xref: /openbmc/linux/drivers/mtd/nand/raw/qcom_nandc.c (revision 27ab1c1c)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2016, The Linux Foundation. All rights reserved.
4  */
5 
6 #include <linux/clk.h>
7 #include <linux/slab.h>
8 #include <linux/bitops.h>
9 #include <linux/dma-mapping.h>
10 #include <linux/dmaengine.h>
11 #include <linux/module.h>
12 #include <linux/mtd/rawnand.h>
13 #include <linux/mtd/partitions.h>
14 #include <linux/of.h>
15 #include <linux/of_device.h>
16 #include <linux/delay.h>
17 #include <linux/dma/qcom_bam_dma.h>
18 
19 /* NANDc reg offsets */
20 #define	NAND_FLASH_CMD			0x00
21 #define	NAND_ADDR0			0x04
22 #define	NAND_ADDR1			0x08
23 #define	NAND_FLASH_CHIP_SELECT		0x0c
24 #define	NAND_EXEC_CMD			0x10
25 #define	NAND_FLASH_STATUS		0x14
26 #define	NAND_BUFFER_STATUS		0x18
27 #define	NAND_DEV0_CFG0			0x20
28 #define	NAND_DEV0_CFG1			0x24
29 #define	NAND_DEV0_ECC_CFG		0x28
30 #define	NAND_DEV1_ECC_CFG		0x2c
31 #define	NAND_DEV1_CFG0			0x30
32 #define	NAND_DEV1_CFG1			0x34
33 #define	NAND_READ_ID			0x40
34 #define	NAND_READ_STATUS		0x44
35 #define	NAND_DEV_CMD0			0xa0
36 #define	NAND_DEV_CMD1			0xa4
37 #define	NAND_DEV_CMD2			0xa8
38 #define	NAND_DEV_CMD_VLD		0xac
39 #define	SFLASHC_BURST_CFG		0xe0
40 #define	NAND_ERASED_CW_DETECT_CFG	0xe8
41 #define	NAND_ERASED_CW_DETECT_STATUS	0xec
42 #define	NAND_EBI2_ECC_BUF_CFG		0xf0
43 #define	FLASH_BUF_ACC			0x100
44 
45 #define	NAND_CTRL			0xf00
46 #define	NAND_VERSION			0xf08
47 #define	NAND_READ_LOCATION_0		0xf20
48 #define	NAND_READ_LOCATION_1		0xf24
49 #define	NAND_READ_LOCATION_2		0xf28
50 #define	NAND_READ_LOCATION_3		0xf2c
51 
52 /* dummy register offsets, used by write_reg_dma */
53 #define	NAND_DEV_CMD1_RESTORE		0xdead
54 #define	NAND_DEV_CMD_VLD_RESTORE	0xbeef
55 
56 /* NAND_FLASH_CMD bits */
57 #define	PAGE_ACC			BIT(4)
58 #define	LAST_PAGE			BIT(5)
59 
60 /* NAND_FLASH_CHIP_SELECT bits */
61 #define	NAND_DEV_SEL			0
62 #define	DM_EN				BIT(2)
63 
64 /* NAND_FLASH_STATUS bits */
65 #define	FS_OP_ERR			BIT(4)
66 #define	FS_READY_BSY_N			BIT(5)
67 #define	FS_MPU_ERR			BIT(8)
68 #define	FS_DEVICE_STS_ERR		BIT(16)
69 #define	FS_DEVICE_WP			BIT(23)
70 
71 /* NAND_BUFFER_STATUS bits */
72 #define	BS_UNCORRECTABLE_BIT		BIT(8)
73 #define	BS_CORRECTABLE_ERR_MSK		0x1f
74 
75 /* NAND_DEVn_CFG0 bits */
76 #define	DISABLE_STATUS_AFTER_WRITE	4
77 #define	CW_PER_PAGE			6
78 #define	UD_SIZE_BYTES			9
79 #define	ECC_PARITY_SIZE_BYTES_RS	19
80 #define	SPARE_SIZE_BYTES		23
81 #define	NUM_ADDR_CYCLES			27
82 #define	STATUS_BFR_READ			30
83 #define	SET_RD_MODE_AFTER_STATUS	31
84 
85 /* NAND_DEVn_CFG0 bits */
86 #define	DEV0_CFG1_ECC_DISABLE		0
87 #define	WIDE_FLASH			1
88 #define	NAND_RECOVERY_CYCLES		2
89 #define	CS_ACTIVE_BSY			5
90 #define	BAD_BLOCK_BYTE_NUM		6
91 #define	BAD_BLOCK_IN_SPARE_AREA		16
92 #define	WR_RD_BSY_GAP			17
93 #define	ENABLE_BCH_ECC			27
94 
95 /* NAND_DEV0_ECC_CFG bits */
96 #define	ECC_CFG_ECC_DISABLE		0
97 #define	ECC_SW_RESET			1
98 #define	ECC_MODE			4
99 #define	ECC_PARITY_SIZE_BYTES_BCH	8
100 #define	ECC_NUM_DATA_BYTES		16
101 #define	ECC_FORCE_CLK_OPEN		30
102 
103 /* NAND_DEV_CMD1 bits */
104 #define	READ_ADDR			0
105 
106 /* NAND_DEV_CMD_VLD bits */
107 #define	READ_START_VLD			BIT(0)
108 #define	READ_STOP_VLD			BIT(1)
109 #define	WRITE_START_VLD			BIT(2)
110 #define	ERASE_START_VLD			BIT(3)
111 #define	SEQ_READ_START_VLD		BIT(4)
112 
113 /* NAND_EBI2_ECC_BUF_CFG bits */
114 #define	NUM_STEPS			0
115 
116 /* NAND_ERASED_CW_DETECT_CFG bits */
117 #define	ERASED_CW_ECC_MASK		1
118 #define	AUTO_DETECT_RES			0
119 #define	MASK_ECC			(1 << ERASED_CW_ECC_MASK)
120 #define	RESET_ERASED_DET		(1 << AUTO_DETECT_RES)
121 #define	ACTIVE_ERASED_DET		(0 << AUTO_DETECT_RES)
122 #define	CLR_ERASED_PAGE_DET		(RESET_ERASED_DET | MASK_ECC)
123 #define	SET_ERASED_PAGE_DET		(ACTIVE_ERASED_DET | MASK_ECC)
124 
125 /* NAND_ERASED_CW_DETECT_STATUS bits */
126 #define	PAGE_ALL_ERASED			BIT(7)
127 #define	CODEWORD_ALL_ERASED		BIT(6)
128 #define	PAGE_ERASED			BIT(5)
129 #define	CODEWORD_ERASED			BIT(4)
130 #define	ERASED_PAGE			(PAGE_ALL_ERASED | PAGE_ERASED)
131 #define	ERASED_CW			(CODEWORD_ALL_ERASED | CODEWORD_ERASED)
132 
133 /* NAND_READ_LOCATION_n bits */
134 #define READ_LOCATION_OFFSET		0
135 #define READ_LOCATION_SIZE		16
136 #define READ_LOCATION_LAST		31
137 
138 /* Version Mask */
139 #define	NAND_VERSION_MAJOR_MASK		0xf0000000
140 #define	NAND_VERSION_MAJOR_SHIFT	28
141 #define	NAND_VERSION_MINOR_MASK		0x0fff0000
142 #define	NAND_VERSION_MINOR_SHIFT	16
143 
144 /* NAND OP_CMDs */
145 #define	OP_PAGE_READ			0x2
146 #define	OP_PAGE_READ_WITH_ECC		0x3
147 #define	OP_PAGE_READ_WITH_ECC_SPARE	0x4
148 #define	OP_PAGE_READ_ONFI_READ		0x5
149 #define	OP_PROGRAM_PAGE			0x6
150 #define	OP_PAGE_PROGRAM_WITH_ECC	0x7
151 #define	OP_PROGRAM_PAGE_SPARE		0x9
152 #define	OP_BLOCK_ERASE			0xa
153 #define	OP_FETCH_ID			0xb
154 #define	OP_RESET_DEVICE			0xd
155 
156 /* Default Value for NAND_DEV_CMD_VLD */
157 #define NAND_DEV_CMD_VLD_VAL		(READ_START_VLD | WRITE_START_VLD | \
158 					 ERASE_START_VLD | SEQ_READ_START_VLD)
159 
160 /* NAND_CTRL bits */
161 #define	BAM_MODE_EN			BIT(0)
162 
163 /*
164  * the NAND controller performs reads/writes with ECC in 516 byte chunks.
165  * the driver calls the chunks 'step' or 'codeword' interchangeably
166  */
167 #define	NANDC_STEP_SIZE			512
168 
169 /*
170  * the largest page size we support is 8K, this will have 16 steps/codewords
171  * of 512 bytes each
172  */
173 #define	MAX_NUM_STEPS			(SZ_8K / NANDC_STEP_SIZE)
174 
175 /* we read at most 3 registers per codeword scan */
176 #define	MAX_REG_RD			(3 * MAX_NUM_STEPS)
177 
178 /* ECC modes supported by the controller */
179 #define	ECC_NONE	BIT(0)
180 #define	ECC_RS_4BIT	BIT(1)
181 #define	ECC_BCH_4BIT	BIT(2)
182 #define	ECC_BCH_8BIT	BIT(3)
183 
184 #define nandc_set_read_loc(nandc, reg, offset, size, is_last)	\
185 nandc_set_reg(nandc, NAND_READ_LOCATION_##reg,			\
186 	      ((offset) << READ_LOCATION_OFFSET) |		\
187 	      ((size) << READ_LOCATION_SIZE) |			\
188 	      ((is_last) << READ_LOCATION_LAST))
189 
190 /*
191  * Returns the actual register address for all NAND_DEV_ registers
192  * (i.e. NAND_DEV_CMD0, NAND_DEV_CMD1, NAND_DEV_CMD2 and NAND_DEV_CMD_VLD)
193  */
194 #define dev_cmd_reg_addr(nandc, reg) ((nandc)->props->dev_cmd_reg_start + (reg))
195 
196 /* Returns the NAND register physical address */
197 #define nandc_reg_phys(chip, offset) ((chip)->base_phys + (offset))
198 
199 /* Returns the dma address for reg read buffer */
200 #define reg_buf_dma_addr(chip, vaddr) \
201 	((chip)->reg_read_dma + \
202 	((uint8_t *)(vaddr) - (uint8_t *)(chip)->reg_read_buf))
203 
204 #define QPIC_PER_CW_CMD_ELEMENTS	32
205 #define QPIC_PER_CW_CMD_SGL		32
206 #define QPIC_PER_CW_DATA_SGL		8
207 
208 #define QPIC_NAND_COMPLETION_TIMEOUT	msecs_to_jiffies(2000)
209 
210 /*
211  * Flags used in DMA descriptor preparation helper functions
212  * (i.e. read_reg_dma/write_reg_dma/read_data_dma/write_data_dma)
213  */
214 /* Don't set the EOT in current tx BAM sgl */
215 #define NAND_BAM_NO_EOT			BIT(0)
216 /* Set the NWD flag in current BAM sgl */
217 #define NAND_BAM_NWD			BIT(1)
218 /* Finish writing in the current BAM sgl and start writing in another BAM sgl */
219 #define NAND_BAM_NEXT_SGL		BIT(2)
220 /*
221  * Erased codeword status is being used two times in single transfer so this
222  * flag will determine the current value of erased codeword status register
223  */
224 #define NAND_ERASED_CW_SET		BIT(4)
225 
226 /*
227  * This data type corresponds to the BAM transaction which will be used for all
228  * NAND transfers.
229  * @bam_ce - the array of BAM command elements
230  * @cmd_sgl - sgl for NAND BAM command pipe
231  * @data_sgl - sgl for NAND BAM consumer/producer pipe
232  * @bam_ce_pos - the index in bam_ce which is available for next sgl
233  * @bam_ce_start - the index in bam_ce which marks the start position ce
234  *		   for current sgl. It will be used for size calculation
235  *		   for current sgl
236  * @cmd_sgl_pos - current index in command sgl.
237  * @cmd_sgl_start - start index in command sgl.
238  * @tx_sgl_pos - current index in data sgl for tx.
239  * @tx_sgl_start - start index in data sgl for tx.
240  * @rx_sgl_pos - current index in data sgl for rx.
241  * @rx_sgl_start - start index in data sgl for rx.
242  * @wait_second_completion - wait for second DMA desc completion before making
243  *			     the NAND transfer completion.
244  * @txn_done - completion for NAND transfer.
245  * @last_data_desc - last DMA desc in data channel (tx/rx).
246  * @last_cmd_desc - last DMA desc in command channel.
247  */
248 struct bam_transaction {
249 	struct bam_cmd_element *bam_ce;
250 	struct scatterlist *cmd_sgl;
251 	struct scatterlist *data_sgl;
252 	u32 bam_ce_pos;
253 	u32 bam_ce_start;
254 	u32 cmd_sgl_pos;
255 	u32 cmd_sgl_start;
256 	u32 tx_sgl_pos;
257 	u32 tx_sgl_start;
258 	u32 rx_sgl_pos;
259 	u32 rx_sgl_start;
260 	bool wait_second_completion;
261 	struct completion txn_done;
262 	struct dma_async_tx_descriptor *last_data_desc;
263 	struct dma_async_tx_descriptor *last_cmd_desc;
264 };
265 
266 /*
267  * This data type corresponds to the nand dma descriptor
268  * @list - list for desc_info
269  * @dir - DMA transfer direction
270  * @adm_sgl - sgl which will be used for single sgl dma descriptor. Only used by
271  *	      ADM
272  * @bam_sgl - sgl which will be used for dma descriptor. Only used by BAM
273  * @sgl_cnt - number of SGL in bam_sgl. Only used by BAM
274  * @dma_desc - low level DMA engine descriptor
275  */
276 struct desc_info {
277 	struct list_head node;
278 
279 	enum dma_data_direction dir;
280 	union {
281 		struct scatterlist adm_sgl;
282 		struct {
283 			struct scatterlist *bam_sgl;
284 			int sgl_cnt;
285 		};
286 	};
287 	struct dma_async_tx_descriptor *dma_desc;
288 };
289 
290 /*
291  * holds the current register values that we want to write. acts as a contiguous
292  * chunk of memory which we use to write the controller registers through DMA.
293  */
294 struct nandc_regs {
295 	__le32 cmd;
296 	__le32 addr0;
297 	__le32 addr1;
298 	__le32 chip_sel;
299 	__le32 exec;
300 
301 	__le32 cfg0;
302 	__le32 cfg1;
303 	__le32 ecc_bch_cfg;
304 
305 	__le32 clrflashstatus;
306 	__le32 clrreadstatus;
307 
308 	__le32 cmd1;
309 	__le32 vld;
310 
311 	__le32 orig_cmd1;
312 	__le32 orig_vld;
313 
314 	__le32 ecc_buf_cfg;
315 	__le32 read_location0;
316 	__le32 read_location1;
317 	__le32 read_location2;
318 	__le32 read_location3;
319 
320 	__le32 erased_cw_detect_cfg_clr;
321 	__le32 erased_cw_detect_cfg_set;
322 };
323 
324 /*
325  * NAND controller data struct
326  *
327  * @controller:			base controller structure
328  * @host_list:			list containing all the chips attached to the
329  *				controller
330  * @dev:			parent device
331  * @base:			MMIO base
332  * @base_phys:			physical base address of controller registers
333  * @base_dma:			dma base address of controller registers
334  * @core_clk:			controller clock
335  * @aon_clk:			another controller clock
336  *
337  * @chan:			dma channel
338  * @cmd_crci:			ADM DMA CRCI for command flow control
339  * @data_crci:			ADM DMA CRCI for data flow control
340  * @desc_list:			DMA descriptor list (list of desc_infos)
341  *
342  * @data_buffer:		our local DMA buffer for page read/writes,
343  *				used when we can't use the buffer provided
344  *				by upper layers directly
345  * @buf_size/count/start:	markers for chip->legacy.read_buf/write_buf
346  *				functions
347  * @reg_read_buf:		local buffer for reading back registers via DMA
348  * @reg_read_dma:		contains dma address for register read buffer
349  * @reg_read_pos:		marker for data read in reg_read_buf
350  *
351  * @regs:			a contiguous chunk of memory for DMA register
352  *				writes. contains the register values to be
353  *				written to controller
354  * @cmd1/vld:			some fixed controller register values
355  * @props:			properties of current NAND controller,
356  *				initialized via DT match data
357  * @max_cwperpage:		maximum QPIC codewords required. calculated
358  *				from all connected NAND devices pagesize
359  */
360 struct qcom_nand_controller {
361 	struct nand_controller controller;
362 	struct list_head host_list;
363 
364 	struct device *dev;
365 
366 	void __iomem *base;
367 	phys_addr_t base_phys;
368 	dma_addr_t base_dma;
369 
370 	struct clk *core_clk;
371 	struct clk *aon_clk;
372 
373 	union {
374 		/* will be used only by QPIC for BAM DMA */
375 		struct {
376 			struct dma_chan *tx_chan;
377 			struct dma_chan *rx_chan;
378 			struct dma_chan *cmd_chan;
379 		};
380 
381 		/* will be used only by EBI2 for ADM DMA */
382 		struct {
383 			struct dma_chan *chan;
384 			unsigned int cmd_crci;
385 			unsigned int data_crci;
386 		};
387 	};
388 
389 	struct list_head desc_list;
390 	struct bam_transaction *bam_txn;
391 
392 	u8		*data_buffer;
393 	int		buf_size;
394 	int		buf_count;
395 	int		buf_start;
396 	unsigned int	max_cwperpage;
397 
398 	__le32 *reg_read_buf;
399 	dma_addr_t reg_read_dma;
400 	int reg_read_pos;
401 
402 	struct nandc_regs *regs;
403 
404 	u32 cmd1, vld;
405 	const struct qcom_nandc_props *props;
406 };
407 
408 /*
409  * NAND chip structure
410  *
411  * @chip:			base NAND chip structure
412  * @node:			list node to add itself to host_list in
413  *				qcom_nand_controller
414  *
415  * @cs:				chip select value for this chip
416  * @cw_size:			the number of bytes in a single step/codeword
417  *				of a page, consisting of all data, ecc, spare
418  *				and reserved bytes
419  * @cw_data:			the number of bytes within a codeword protected
420  *				by ECC
421  * @use_ecc:			request the controller to use ECC for the
422  *				upcoming read/write
423  * @bch_enabled:		flag to tell whether BCH ECC mode is used
424  * @ecc_bytes_hw:		ECC bytes used by controller hardware for this
425  *				chip
426  * @status:			value to be returned if NAND_CMD_STATUS command
427  *				is executed
428  * @last_command:		keeps track of last command on this chip. used
429  *				for reading correct status
430  *
431  * @cfg0, cfg1, cfg0_raw..:	NANDc register configurations needed for
432  *				ecc/non-ecc mode for the current nand flash
433  *				device
434  */
435 struct qcom_nand_host {
436 	struct nand_chip chip;
437 	struct list_head node;
438 
439 	int cs;
440 	int cw_size;
441 	int cw_data;
442 	bool use_ecc;
443 	bool bch_enabled;
444 	int ecc_bytes_hw;
445 	int spare_bytes;
446 	int bbm_size;
447 	u8 status;
448 	int last_command;
449 
450 	u32 cfg0, cfg1;
451 	u32 cfg0_raw, cfg1_raw;
452 	u32 ecc_buf_cfg;
453 	u32 ecc_bch_cfg;
454 	u32 clrflashstatus;
455 	u32 clrreadstatus;
456 };
457 
458 /*
459  * This data type corresponds to the NAND controller properties which varies
460  * among different NAND controllers.
461  * @ecc_modes - ecc mode for NAND
462  * @is_bam - whether NAND controller is using BAM
463  * @is_qpic - whether NAND CTRL is part of qpic IP
464  * @qpic_v2 - flag to indicate QPIC IP version 2
465  * @dev_cmd_reg_start - NAND_DEV_CMD_* registers starting offset
466  */
467 struct qcom_nandc_props {
468 	u32 ecc_modes;
469 	bool is_bam;
470 	bool is_qpic;
471 	bool qpic_v2;
472 	u32 dev_cmd_reg_start;
473 };
474 
475 /* Frees the BAM transaction memory */
476 static void free_bam_transaction(struct qcom_nand_controller *nandc)
477 {
478 	struct bam_transaction *bam_txn = nandc->bam_txn;
479 
480 	devm_kfree(nandc->dev, bam_txn);
481 }
482 
483 /* Allocates and Initializes the BAM transaction */
484 static struct bam_transaction *
485 alloc_bam_transaction(struct qcom_nand_controller *nandc)
486 {
487 	struct bam_transaction *bam_txn;
488 	size_t bam_txn_size;
489 	unsigned int num_cw = nandc->max_cwperpage;
490 	void *bam_txn_buf;
491 
492 	bam_txn_size =
493 		sizeof(*bam_txn) + num_cw *
494 		((sizeof(*bam_txn->bam_ce) * QPIC_PER_CW_CMD_ELEMENTS) +
495 		(sizeof(*bam_txn->cmd_sgl) * QPIC_PER_CW_CMD_SGL) +
496 		(sizeof(*bam_txn->data_sgl) * QPIC_PER_CW_DATA_SGL));
497 
498 	bam_txn_buf = devm_kzalloc(nandc->dev, bam_txn_size, GFP_KERNEL);
499 	if (!bam_txn_buf)
500 		return NULL;
501 
502 	bam_txn = bam_txn_buf;
503 	bam_txn_buf += sizeof(*bam_txn);
504 
505 	bam_txn->bam_ce = bam_txn_buf;
506 	bam_txn_buf +=
507 		sizeof(*bam_txn->bam_ce) * QPIC_PER_CW_CMD_ELEMENTS * num_cw;
508 
509 	bam_txn->cmd_sgl = bam_txn_buf;
510 	bam_txn_buf +=
511 		sizeof(*bam_txn->cmd_sgl) * QPIC_PER_CW_CMD_SGL * num_cw;
512 
513 	bam_txn->data_sgl = bam_txn_buf;
514 
515 	init_completion(&bam_txn->txn_done);
516 
517 	return bam_txn;
518 }
519 
520 /* Clears the BAM transaction indexes */
521 static void clear_bam_transaction(struct qcom_nand_controller *nandc)
522 {
523 	struct bam_transaction *bam_txn = nandc->bam_txn;
524 
525 	if (!nandc->props->is_bam)
526 		return;
527 
528 	bam_txn->bam_ce_pos = 0;
529 	bam_txn->bam_ce_start = 0;
530 	bam_txn->cmd_sgl_pos = 0;
531 	bam_txn->cmd_sgl_start = 0;
532 	bam_txn->tx_sgl_pos = 0;
533 	bam_txn->tx_sgl_start = 0;
534 	bam_txn->rx_sgl_pos = 0;
535 	bam_txn->rx_sgl_start = 0;
536 	bam_txn->last_data_desc = NULL;
537 	bam_txn->wait_second_completion = false;
538 
539 	sg_init_table(bam_txn->cmd_sgl, nandc->max_cwperpage *
540 		      QPIC_PER_CW_CMD_SGL);
541 	sg_init_table(bam_txn->data_sgl, nandc->max_cwperpage *
542 		      QPIC_PER_CW_DATA_SGL);
543 
544 	reinit_completion(&bam_txn->txn_done);
545 }
546 
547 /* Callback for DMA descriptor completion */
548 static void qpic_bam_dma_done(void *data)
549 {
550 	struct bam_transaction *bam_txn = data;
551 
552 	/*
553 	 * In case of data transfer with NAND, 2 callbacks will be generated.
554 	 * One for command channel and another one for data channel.
555 	 * If current transaction has data descriptors
556 	 * (i.e. wait_second_completion is true), then set this to false
557 	 * and wait for second DMA descriptor completion.
558 	 */
559 	if (bam_txn->wait_second_completion)
560 		bam_txn->wait_second_completion = false;
561 	else
562 		complete(&bam_txn->txn_done);
563 }
564 
565 static inline struct qcom_nand_host *to_qcom_nand_host(struct nand_chip *chip)
566 {
567 	return container_of(chip, struct qcom_nand_host, chip);
568 }
569 
570 static inline struct qcom_nand_controller *
571 get_qcom_nand_controller(struct nand_chip *chip)
572 {
573 	return container_of(chip->controller, struct qcom_nand_controller,
574 			    controller);
575 }
576 
577 static inline u32 nandc_read(struct qcom_nand_controller *nandc, int offset)
578 {
579 	return ioread32(nandc->base + offset);
580 }
581 
582 static inline void nandc_write(struct qcom_nand_controller *nandc, int offset,
583 			       u32 val)
584 {
585 	iowrite32(val, nandc->base + offset);
586 }
587 
588 static inline void nandc_read_buffer_sync(struct qcom_nand_controller *nandc,
589 					  bool is_cpu)
590 {
591 	if (!nandc->props->is_bam)
592 		return;
593 
594 	if (is_cpu)
595 		dma_sync_single_for_cpu(nandc->dev, nandc->reg_read_dma,
596 					MAX_REG_RD *
597 					sizeof(*nandc->reg_read_buf),
598 					DMA_FROM_DEVICE);
599 	else
600 		dma_sync_single_for_device(nandc->dev, nandc->reg_read_dma,
601 					   MAX_REG_RD *
602 					   sizeof(*nandc->reg_read_buf),
603 					   DMA_FROM_DEVICE);
604 }
605 
606 static __le32 *offset_to_nandc_reg(struct nandc_regs *regs, int offset)
607 {
608 	switch (offset) {
609 	case NAND_FLASH_CMD:
610 		return &regs->cmd;
611 	case NAND_ADDR0:
612 		return &regs->addr0;
613 	case NAND_ADDR1:
614 		return &regs->addr1;
615 	case NAND_FLASH_CHIP_SELECT:
616 		return &regs->chip_sel;
617 	case NAND_EXEC_CMD:
618 		return &regs->exec;
619 	case NAND_FLASH_STATUS:
620 		return &regs->clrflashstatus;
621 	case NAND_DEV0_CFG0:
622 		return &regs->cfg0;
623 	case NAND_DEV0_CFG1:
624 		return &regs->cfg1;
625 	case NAND_DEV0_ECC_CFG:
626 		return &regs->ecc_bch_cfg;
627 	case NAND_READ_STATUS:
628 		return &regs->clrreadstatus;
629 	case NAND_DEV_CMD1:
630 		return &regs->cmd1;
631 	case NAND_DEV_CMD1_RESTORE:
632 		return &regs->orig_cmd1;
633 	case NAND_DEV_CMD_VLD:
634 		return &regs->vld;
635 	case NAND_DEV_CMD_VLD_RESTORE:
636 		return &regs->orig_vld;
637 	case NAND_EBI2_ECC_BUF_CFG:
638 		return &regs->ecc_buf_cfg;
639 	case NAND_READ_LOCATION_0:
640 		return &regs->read_location0;
641 	case NAND_READ_LOCATION_1:
642 		return &regs->read_location1;
643 	case NAND_READ_LOCATION_2:
644 		return &regs->read_location2;
645 	case NAND_READ_LOCATION_3:
646 		return &regs->read_location3;
647 	default:
648 		return NULL;
649 	}
650 }
651 
652 static void nandc_set_reg(struct qcom_nand_controller *nandc, int offset,
653 			  u32 val)
654 {
655 	struct nandc_regs *regs = nandc->regs;
656 	__le32 *reg;
657 
658 	reg = offset_to_nandc_reg(regs, offset);
659 
660 	if (reg)
661 		*reg = cpu_to_le32(val);
662 }
663 
664 /* helper to configure address register values */
665 static void set_address(struct qcom_nand_host *host, u16 column, int page)
666 {
667 	struct nand_chip *chip = &host->chip;
668 	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
669 
670 	if (chip->options & NAND_BUSWIDTH_16)
671 		column >>= 1;
672 
673 	nandc_set_reg(nandc, NAND_ADDR0, page << 16 | column);
674 	nandc_set_reg(nandc, NAND_ADDR1, page >> 16 & 0xff);
675 }
676 
677 /*
678  * update_rw_regs:	set up read/write register values, these will be
679  *			written to the NAND controller registers via DMA
680  *
681  * @num_cw:		number of steps for the read/write operation
682  * @read:		read or write operation
683  */
684 static void update_rw_regs(struct qcom_nand_host *host, int num_cw, bool read)
685 {
686 	struct nand_chip *chip = &host->chip;
687 	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
688 	u32 cmd, cfg0, cfg1, ecc_bch_cfg;
689 
690 	if (read) {
691 		if (host->use_ecc)
692 			cmd = OP_PAGE_READ_WITH_ECC | PAGE_ACC | LAST_PAGE;
693 		else
694 			cmd = OP_PAGE_READ | PAGE_ACC | LAST_PAGE;
695 	} else {
696 		cmd = OP_PROGRAM_PAGE | PAGE_ACC | LAST_PAGE;
697 	}
698 
699 	if (host->use_ecc) {
700 		cfg0 = (host->cfg0 & ~(7U << CW_PER_PAGE)) |
701 				(num_cw - 1) << CW_PER_PAGE;
702 
703 		cfg1 = host->cfg1;
704 		ecc_bch_cfg = host->ecc_bch_cfg;
705 	} else {
706 		cfg0 = (host->cfg0_raw & ~(7U << CW_PER_PAGE)) |
707 				(num_cw - 1) << CW_PER_PAGE;
708 
709 		cfg1 = host->cfg1_raw;
710 		ecc_bch_cfg = 1 << ECC_CFG_ECC_DISABLE;
711 	}
712 
713 	nandc_set_reg(nandc, NAND_FLASH_CMD, cmd);
714 	nandc_set_reg(nandc, NAND_DEV0_CFG0, cfg0);
715 	nandc_set_reg(nandc, NAND_DEV0_CFG1, cfg1);
716 	nandc_set_reg(nandc, NAND_DEV0_ECC_CFG, ecc_bch_cfg);
717 	nandc_set_reg(nandc, NAND_EBI2_ECC_BUF_CFG, host->ecc_buf_cfg);
718 	nandc_set_reg(nandc, NAND_FLASH_STATUS, host->clrflashstatus);
719 	nandc_set_reg(nandc, NAND_READ_STATUS, host->clrreadstatus);
720 	nandc_set_reg(nandc, NAND_EXEC_CMD, 1);
721 
722 	if (read)
723 		nandc_set_read_loc(nandc, 0, 0, host->use_ecc ?
724 				   host->cw_data : host->cw_size, 1);
725 }
726 
727 /*
728  * Maps the scatter gather list for DMA transfer and forms the DMA descriptor
729  * for BAM. This descriptor will be added in the NAND DMA descriptor queue
730  * which will be submitted to DMA engine.
731  */
732 static int prepare_bam_async_desc(struct qcom_nand_controller *nandc,
733 				  struct dma_chan *chan,
734 				  unsigned long flags)
735 {
736 	struct desc_info *desc;
737 	struct scatterlist *sgl;
738 	unsigned int sgl_cnt;
739 	int ret;
740 	struct bam_transaction *bam_txn = nandc->bam_txn;
741 	enum dma_transfer_direction dir_eng;
742 	struct dma_async_tx_descriptor *dma_desc;
743 
744 	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
745 	if (!desc)
746 		return -ENOMEM;
747 
748 	if (chan == nandc->cmd_chan) {
749 		sgl = &bam_txn->cmd_sgl[bam_txn->cmd_sgl_start];
750 		sgl_cnt = bam_txn->cmd_sgl_pos - bam_txn->cmd_sgl_start;
751 		bam_txn->cmd_sgl_start = bam_txn->cmd_sgl_pos;
752 		dir_eng = DMA_MEM_TO_DEV;
753 		desc->dir = DMA_TO_DEVICE;
754 	} else if (chan == nandc->tx_chan) {
755 		sgl = &bam_txn->data_sgl[bam_txn->tx_sgl_start];
756 		sgl_cnt = bam_txn->tx_sgl_pos - bam_txn->tx_sgl_start;
757 		bam_txn->tx_sgl_start = bam_txn->tx_sgl_pos;
758 		dir_eng = DMA_MEM_TO_DEV;
759 		desc->dir = DMA_TO_DEVICE;
760 	} else {
761 		sgl = &bam_txn->data_sgl[bam_txn->rx_sgl_start];
762 		sgl_cnt = bam_txn->rx_sgl_pos - bam_txn->rx_sgl_start;
763 		bam_txn->rx_sgl_start = bam_txn->rx_sgl_pos;
764 		dir_eng = DMA_DEV_TO_MEM;
765 		desc->dir = DMA_FROM_DEVICE;
766 	}
767 
768 	sg_mark_end(sgl + sgl_cnt - 1);
769 	ret = dma_map_sg(nandc->dev, sgl, sgl_cnt, desc->dir);
770 	if (ret == 0) {
771 		dev_err(nandc->dev, "failure in mapping desc\n");
772 		kfree(desc);
773 		return -ENOMEM;
774 	}
775 
776 	desc->sgl_cnt = sgl_cnt;
777 	desc->bam_sgl = sgl;
778 
779 	dma_desc = dmaengine_prep_slave_sg(chan, sgl, sgl_cnt, dir_eng,
780 					   flags);
781 
782 	if (!dma_desc) {
783 		dev_err(nandc->dev, "failure in prep desc\n");
784 		dma_unmap_sg(nandc->dev, sgl, sgl_cnt, desc->dir);
785 		kfree(desc);
786 		return -EINVAL;
787 	}
788 
789 	desc->dma_desc = dma_desc;
790 
791 	/* update last data/command descriptor */
792 	if (chan == nandc->cmd_chan)
793 		bam_txn->last_cmd_desc = dma_desc;
794 	else
795 		bam_txn->last_data_desc = dma_desc;
796 
797 	list_add_tail(&desc->node, &nandc->desc_list);
798 
799 	return 0;
800 }
801 
802 /*
803  * Prepares the command descriptor for BAM DMA which will be used for NAND
804  * register reads and writes. The command descriptor requires the command
805  * to be formed in command element type so this function uses the command
806  * element from bam transaction ce array and fills the same with required
807  * data. A single SGL can contain multiple command elements so
808  * NAND_BAM_NEXT_SGL will be used for starting the separate SGL
809  * after the current command element.
810  */
811 static int prep_bam_dma_desc_cmd(struct qcom_nand_controller *nandc, bool read,
812 				 int reg_off, const void *vaddr,
813 				 int size, unsigned int flags)
814 {
815 	int bam_ce_size;
816 	int i, ret;
817 	struct bam_cmd_element *bam_ce_buffer;
818 	struct bam_transaction *bam_txn = nandc->bam_txn;
819 
820 	bam_ce_buffer = &bam_txn->bam_ce[bam_txn->bam_ce_pos];
821 
822 	/* fill the command desc */
823 	for (i = 0; i < size; i++) {
824 		if (read)
825 			bam_prep_ce(&bam_ce_buffer[i],
826 				    nandc_reg_phys(nandc, reg_off + 4 * i),
827 				    BAM_READ_COMMAND,
828 				    reg_buf_dma_addr(nandc,
829 						     (__le32 *)vaddr + i));
830 		else
831 			bam_prep_ce_le32(&bam_ce_buffer[i],
832 					 nandc_reg_phys(nandc, reg_off + 4 * i),
833 					 BAM_WRITE_COMMAND,
834 					 *((__le32 *)vaddr + i));
835 	}
836 
837 	bam_txn->bam_ce_pos += size;
838 
839 	/* use the separate sgl after this command */
840 	if (flags & NAND_BAM_NEXT_SGL) {
841 		bam_ce_buffer = &bam_txn->bam_ce[bam_txn->bam_ce_start];
842 		bam_ce_size = (bam_txn->bam_ce_pos -
843 				bam_txn->bam_ce_start) *
844 				sizeof(struct bam_cmd_element);
845 		sg_set_buf(&bam_txn->cmd_sgl[bam_txn->cmd_sgl_pos],
846 			   bam_ce_buffer, bam_ce_size);
847 		bam_txn->cmd_sgl_pos++;
848 		bam_txn->bam_ce_start = bam_txn->bam_ce_pos;
849 
850 		if (flags & NAND_BAM_NWD) {
851 			ret = prepare_bam_async_desc(nandc, nandc->cmd_chan,
852 						     DMA_PREP_FENCE |
853 						     DMA_PREP_CMD);
854 			if (ret)
855 				return ret;
856 		}
857 	}
858 
859 	return 0;
860 }
861 
862 /*
863  * Prepares the data descriptor for BAM DMA which will be used for NAND
864  * data reads and writes.
865  */
866 static int prep_bam_dma_desc_data(struct qcom_nand_controller *nandc, bool read,
867 				  const void *vaddr,
868 				  int size, unsigned int flags)
869 {
870 	int ret;
871 	struct bam_transaction *bam_txn = nandc->bam_txn;
872 
873 	if (read) {
874 		sg_set_buf(&bam_txn->data_sgl[bam_txn->rx_sgl_pos],
875 			   vaddr, size);
876 		bam_txn->rx_sgl_pos++;
877 	} else {
878 		sg_set_buf(&bam_txn->data_sgl[bam_txn->tx_sgl_pos],
879 			   vaddr, size);
880 		bam_txn->tx_sgl_pos++;
881 
882 		/*
883 		 * BAM will only set EOT for DMA_PREP_INTERRUPT so if this flag
884 		 * is not set, form the DMA descriptor
885 		 */
886 		if (!(flags & NAND_BAM_NO_EOT)) {
887 			ret = prepare_bam_async_desc(nandc, nandc->tx_chan,
888 						     DMA_PREP_INTERRUPT);
889 			if (ret)
890 				return ret;
891 		}
892 	}
893 
894 	return 0;
895 }
896 
897 static int prep_adm_dma_desc(struct qcom_nand_controller *nandc, bool read,
898 			     int reg_off, const void *vaddr, int size,
899 			     bool flow_control)
900 {
901 	struct desc_info *desc;
902 	struct dma_async_tx_descriptor *dma_desc;
903 	struct scatterlist *sgl;
904 	struct dma_slave_config slave_conf;
905 	enum dma_transfer_direction dir_eng;
906 	int ret;
907 
908 	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
909 	if (!desc)
910 		return -ENOMEM;
911 
912 	sgl = &desc->adm_sgl;
913 
914 	sg_init_one(sgl, vaddr, size);
915 
916 	if (read) {
917 		dir_eng = DMA_DEV_TO_MEM;
918 		desc->dir = DMA_FROM_DEVICE;
919 	} else {
920 		dir_eng = DMA_MEM_TO_DEV;
921 		desc->dir = DMA_TO_DEVICE;
922 	}
923 
924 	ret = dma_map_sg(nandc->dev, sgl, 1, desc->dir);
925 	if (ret == 0) {
926 		ret = -ENOMEM;
927 		goto err;
928 	}
929 
930 	memset(&slave_conf, 0x00, sizeof(slave_conf));
931 
932 	slave_conf.device_fc = flow_control;
933 	if (read) {
934 		slave_conf.src_maxburst = 16;
935 		slave_conf.src_addr = nandc->base_dma + reg_off;
936 		slave_conf.slave_id = nandc->data_crci;
937 	} else {
938 		slave_conf.dst_maxburst = 16;
939 		slave_conf.dst_addr = nandc->base_dma + reg_off;
940 		slave_conf.slave_id = nandc->cmd_crci;
941 	}
942 
943 	ret = dmaengine_slave_config(nandc->chan, &slave_conf);
944 	if (ret) {
945 		dev_err(nandc->dev, "failed to configure dma channel\n");
946 		goto err;
947 	}
948 
949 	dma_desc = dmaengine_prep_slave_sg(nandc->chan, sgl, 1, dir_eng, 0);
950 	if (!dma_desc) {
951 		dev_err(nandc->dev, "failed to prepare desc\n");
952 		ret = -EINVAL;
953 		goto err;
954 	}
955 
956 	desc->dma_desc = dma_desc;
957 
958 	list_add_tail(&desc->node, &nandc->desc_list);
959 
960 	return 0;
961 err:
962 	kfree(desc);
963 
964 	return ret;
965 }
966 
967 /*
968  * read_reg_dma:	prepares a descriptor to read a given number of
969  *			contiguous registers to the reg_read_buf pointer
970  *
971  * @first:		offset of the first register in the contiguous block
972  * @num_regs:		number of registers to read
973  * @flags:		flags to control DMA descriptor preparation
974  */
975 static int read_reg_dma(struct qcom_nand_controller *nandc, int first,
976 			int num_regs, unsigned int flags)
977 {
978 	bool flow_control = false;
979 	void *vaddr;
980 
981 	vaddr = nandc->reg_read_buf + nandc->reg_read_pos;
982 	nandc->reg_read_pos += num_regs;
983 
984 	if (first == NAND_DEV_CMD_VLD || first == NAND_DEV_CMD1)
985 		first = dev_cmd_reg_addr(nandc, first);
986 
987 	if (nandc->props->is_bam)
988 		return prep_bam_dma_desc_cmd(nandc, true, first, vaddr,
989 					     num_regs, flags);
990 
991 	if (first == NAND_READ_ID || first == NAND_FLASH_STATUS)
992 		flow_control = true;
993 
994 	return prep_adm_dma_desc(nandc, true, first, vaddr,
995 				 num_regs * sizeof(u32), flow_control);
996 }
997 
998 /*
999  * write_reg_dma:	prepares a descriptor to write a given number of
1000  *			contiguous registers
1001  *
1002  * @first:		offset of the first register in the contiguous block
1003  * @num_regs:		number of registers to write
1004  * @flags:		flags to control DMA descriptor preparation
1005  */
1006 static int write_reg_dma(struct qcom_nand_controller *nandc, int first,
1007 			 int num_regs, unsigned int flags)
1008 {
1009 	bool flow_control = false;
1010 	struct nandc_regs *regs = nandc->regs;
1011 	void *vaddr;
1012 
1013 	vaddr = offset_to_nandc_reg(regs, first);
1014 
1015 	if (first == NAND_ERASED_CW_DETECT_CFG) {
1016 		if (flags & NAND_ERASED_CW_SET)
1017 			vaddr = &regs->erased_cw_detect_cfg_set;
1018 		else
1019 			vaddr = &regs->erased_cw_detect_cfg_clr;
1020 	}
1021 
1022 	if (first == NAND_EXEC_CMD)
1023 		flags |= NAND_BAM_NWD;
1024 
1025 	if (first == NAND_DEV_CMD1_RESTORE || first == NAND_DEV_CMD1)
1026 		first = dev_cmd_reg_addr(nandc, NAND_DEV_CMD1);
1027 
1028 	if (first == NAND_DEV_CMD_VLD_RESTORE || first == NAND_DEV_CMD_VLD)
1029 		first = dev_cmd_reg_addr(nandc, NAND_DEV_CMD_VLD);
1030 
1031 	if (nandc->props->is_bam)
1032 		return prep_bam_dma_desc_cmd(nandc, false, first, vaddr,
1033 					     num_regs, flags);
1034 
1035 	if (first == NAND_FLASH_CMD)
1036 		flow_control = true;
1037 
1038 	return prep_adm_dma_desc(nandc, false, first, vaddr,
1039 				 num_regs * sizeof(u32), flow_control);
1040 }
1041 
1042 /*
1043  * read_data_dma:	prepares a DMA descriptor to transfer data from the
1044  *			controller's internal buffer to the buffer 'vaddr'
1045  *
1046  * @reg_off:		offset within the controller's data buffer
1047  * @vaddr:		virtual address of the buffer we want to write to
1048  * @size:		DMA transaction size in bytes
1049  * @flags:		flags to control DMA descriptor preparation
1050  */
1051 static int read_data_dma(struct qcom_nand_controller *nandc, int reg_off,
1052 			 const u8 *vaddr, int size, unsigned int flags)
1053 {
1054 	if (nandc->props->is_bam)
1055 		return prep_bam_dma_desc_data(nandc, true, vaddr, size, flags);
1056 
1057 	return prep_adm_dma_desc(nandc, true, reg_off, vaddr, size, false);
1058 }
1059 
1060 /*
1061  * write_data_dma:	prepares a DMA descriptor to transfer data from
1062  *			'vaddr' to the controller's internal buffer
1063  *
1064  * @reg_off:		offset within the controller's data buffer
1065  * @vaddr:		virtual address of the buffer we want to read from
1066  * @size:		DMA transaction size in bytes
1067  * @flags:		flags to control DMA descriptor preparation
1068  */
1069 static int write_data_dma(struct qcom_nand_controller *nandc, int reg_off,
1070 			  const u8 *vaddr, int size, unsigned int flags)
1071 {
1072 	if (nandc->props->is_bam)
1073 		return prep_bam_dma_desc_data(nandc, false, vaddr, size, flags);
1074 
1075 	return prep_adm_dma_desc(nandc, false, reg_off, vaddr, size, false);
1076 }
1077 
1078 /*
1079  * Helper to prepare DMA descriptors for configuring registers
1080  * before reading a NAND page.
1081  */
1082 static void config_nand_page_read(struct qcom_nand_controller *nandc)
1083 {
1084 	write_reg_dma(nandc, NAND_ADDR0, 2, 0);
1085 	write_reg_dma(nandc, NAND_DEV0_CFG0, 3, 0);
1086 	write_reg_dma(nandc, NAND_EBI2_ECC_BUF_CFG, 1, 0);
1087 	write_reg_dma(nandc, NAND_ERASED_CW_DETECT_CFG, 1, 0);
1088 	write_reg_dma(nandc, NAND_ERASED_CW_DETECT_CFG, 1,
1089 		      NAND_ERASED_CW_SET | NAND_BAM_NEXT_SGL);
1090 }
1091 
1092 /*
1093  * Helper to prepare DMA descriptors for configuring registers
1094  * before reading each codeword in NAND page.
1095  */
1096 static void
1097 config_nand_cw_read(struct qcom_nand_controller *nandc, bool use_ecc)
1098 {
1099 	if (nandc->props->is_bam)
1100 		write_reg_dma(nandc, NAND_READ_LOCATION_0, 4,
1101 			      NAND_BAM_NEXT_SGL);
1102 
1103 	write_reg_dma(nandc, NAND_FLASH_CMD, 1, NAND_BAM_NEXT_SGL);
1104 	write_reg_dma(nandc, NAND_EXEC_CMD, 1, NAND_BAM_NEXT_SGL);
1105 
1106 	if (use_ecc) {
1107 		read_reg_dma(nandc, NAND_FLASH_STATUS, 2, 0);
1108 		read_reg_dma(nandc, NAND_ERASED_CW_DETECT_STATUS, 1,
1109 			     NAND_BAM_NEXT_SGL);
1110 	} else {
1111 		read_reg_dma(nandc, NAND_FLASH_STATUS, 1, NAND_BAM_NEXT_SGL);
1112 	}
1113 }
1114 
1115 /*
1116  * Helper to prepare dma descriptors to configure registers needed for reading a
1117  * single codeword in page
1118  */
1119 static void
1120 config_nand_single_cw_page_read(struct qcom_nand_controller *nandc,
1121 				bool use_ecc)
1122 {
1123 	config_nand_page_read(nandc);
1124 	config_nand_cw_read(nandc, use_ecc);
1125 }
1126 
1127 /*
1128  * Helper to prepare DMA descriptors used to configure registers needed for
1129  * before writing a NAND page.
1130  */
1131 static void config_nand_page_write(struct qcom_nand_controller *nandc)
1132 {
1133 	write_reg_dma(nandc, NAND_ADDR0, 2, 0);
1134 	write_reg_dma(nandc, NAND_DEV0_CFG0, 3, 0);
1135 	write_reg_dma(nandc, NAND_EBI2_ECC_BUF_CFG, 1,
1136 		      NAND_BAM_NEXT_SGL);
1137 }
1138 
1139 /*
1140  * Helper to prepare DMA descriptors for configuring registers
1141  * before writing each codeword in NAND page.
1142  */
1143 static void config_nand_cw_write(struct qcom_nand_controller *nandc)
1144 {
1145 	write_reg_dma(nandc, NAND_FLASH_CMD, 1, NAND_BAM_NEXT_SGL);
1146 	write_reg_dma(nandc, NAND_EXEC_CMD, 1, NAND_BAM_NEXT_SGL);
1147 
1148 	read_reg_dma(nandc, NAND_FLASH_STATUS, 1, NAND_BAM_NEXT_SGL);
1149 
1150 	write_reg_dma(nandc, NAND_FLASH_STATUS, 1, 0);
1151 	write_reg_dma(nandc, NAND_READ_STATUS, 1, NAND_BAM_NEXT_SGL);
1152 }
1153 
1154 /*
1155  * the following functions are used within chip->legacy.cmdfunc() to
1156  * perform different NAND_CMD_* commands
1157  */
1158 
1159 /* sets up descriptors for NAND_CMD_PARAM */
1160 static int nandc_param(struct qcom_nand_host *host)
1161 {
1162 	struct nand_chip *chip = &host->chip;
1163 	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
1164 
1165 	/*
1166 	 * NAND_CMD_PARAM is called before we know much about the FLASH chip
1167 	 * in use. we configure the controller to perform a raw read of 512
1168 	 * bytes to read onfi params
1169 	 */
1170 	if (nandc->props->qpic_v2)
1171 		nandc_set_reg(nandc, NAND_FLASH_CMD, OP_PAGE_READ_ONFI_READ |
1172 			      PAGE_ACC | LAST_PAGE);
1173 	else
1174 		nandc_set_reg(nandc, NAND_FLASH_CMD, OP_PAGE_READ |
1175 			      PAGE_ACC | LAST_PAGE);
1176 
1177 	nandc_set_reg(nandc, NAND_ADDR0, 0);
1178 	nandc_set_reg(nandc, NAND_ADDR1, 0);
1179 	nandc_set_reg(nandc, NAND_DEV0_CFG0, 0 << CW_PER_PAGE
1180 					| 512 << UD_SIZE_BYTES
1181 					| 5 << NUM_ADDR_CYCLES
1182 					| 0 << SPARE_SIZE_BYTES);
1183 	nandc_set_reg(nandc, NAND_DEV0_CFG1, 7 << NAND_RECOVERY_CYCLES
1184 					| 0 << CS_ACTIVE_BSY
1185 					| 17 << BAD_BLOCK_BYTE_NUM
1186 					| 1 << BAD_BLOCK_IN_SPARE_AREA
1187 					| 2 << WR_RD_BSY_GAP
1188 					| 0 << WIDE_FLASH
1189 					| 1 << DEV0_CFG1_ECC_DISABLE);
1190 	nandc_set_reg(nandc, NAND_EBI2_ECC_BUF_CFG, 1 << ECC_CFG_ECC_DISABLE);
1191 
1192 	/* configure CMD1 and VLD for ONFI param probing in QPIC v1 */
1193 	if (!nandc->props->qpic_v2) {
1194 		nandc_set_reg(nandc, NAND_DEV_CMD_VLD,
1195 			      (nandc->vld & ~READ_START_VLD));
1196 		nandc_set_reg(nandc, NAND_DEV_CMD1,
1197 			      (nandc->cmd1 & ~(0xFF << READ_ADDR))
1198 			      | NAND_CMD_PARAM << READ_ADDR);
1199 	}
1200 
1201 	nandc_set_reg(nandc, NAND_EXEC_CMD, 1);
1202 
1203 	if (!nandc->props->qpic_v2) {
1204 		nandc_set_reg(nandc, NAND_DEV_CMD1_RESTORE, nandc->cmd1);
1205 		nandc_set_reg(nandc, NAND_DEV_CMD_VLD_RESTORE, nandc->vld);
1206 	}
1207 
1208 	nandc_set_read_loc(nandc, 0, 0, 512, 1);
1209 
1210 	if (!nandc->props->qpic_v2) {
1211 		write_reg_dma(nandc, NAND_DEV_CMD_VLD, 1, 0);
1212 		write_reg_dma(nandc, NAND_DEV_CMD1, 1, NAND_BAM_NEXT_SGL);
1213 	}
1214 
1215 	nandc->buf_count = 512;
1216 	memset(nandc->data_buffer, 0xff, nandc->buf_count);
1217 
1218 	config_nand_single_cw_page_read(nandc, false);
1219 
1220 	read_data_dma(nandc, FLASH_BUF_ACC, nandc->data_buffer,
1221 		      nandc->buf_count, 0);
1222 
1223 	/* restore CMD1 and VLD regs */
1224 	if (!nandc->props->qpic_v2) {
1225 		write_reg_dma(nandc, NAND_DEV_CMD1_RESTORE, 1, 0);
1226 		write_reg_dma(nandc, NAND_DEV_CMD_VLD_RESTORE, 1, NAND_BAM_NEXT_SGL);
1227 	}
1228 
1229 	return 0;
1230 }
1231 
1232 /* sets up descriptors for NAND_CMD_ERASE1 */
1233 static int erase_block(struct qcom_nand_host *host, int page_addr)
1234 {
1235 	struct nand_chip *chip = &host->chip;
1236 	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
1237 
1238 	nandc_set_reg(nandc, NAND_FLASH_CMD,
1239 		      OP_BLOCK_ERASE | PAGE_ACC | LAST_PAGE);
1240 	nandc_set_reg(nandc, NAND_ADDR0, page_addr);
1241 	nandc_set_reg(nandc, NAND_ADDR1, 0);
1242 	nandc_set_reg(nandc, NAND_DEV0_CFG0,
1243 		      host->cfg0_raw & ~(7 << CW_PER_PAGE));
1244 	nandc_set_reg(nandc, NAND_DEV0_CFG1, host->cfg1_raw);
1245 	nandc_set_reg(nandc, NAND_EXEC_CMD, 1);
1246 	nandc_set_reg(nandc, NAND_FLASH_STATUS, host->clrflashstatus);
1247 	nandc_set_reg(nandc, NAND_READ_STATUS, host->clrreadstatus);
1248 
1249 	write_reg_dma(nandc, NAND_FLASH_CMD, 3, NAND_BAM_NEXT_SGL);
1250 	write_reg_dma(nandc, NAND_DEV0_CFG0, 2, NAND_BAM_NEXT_SGL);
1251 	write_reg_dma(nandc, NAND_EXEC_CMD, 1, NAND_BAM_NEXT_SGL);
1252 
1253 	read_reg_dma(nandc, NAND_FLASH_STATUS, 1, NAND_BAM_NEXT_SGL);
1254 
1255 	write_reg_dma(nandc, NAND_FLASH_STATUS, 1, 0);
1256 	write_reg_dma(nandc, NAND_READ_STATUS, 1, NAND_BAM_NEXT_SGL);
1257 
1258 	return 0;
1259 }
1260 
1261 /* sets up descriptors for NAND_CMD_READID */
1262 static int read_id(struct qcom_nand_host *host, int column)
1263 {
1264 	struct nand_chip *chip = &host->chip;
1265 	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
1266 
1267 	if (column == -1)
1268 		return 0;
1269 
1270 	nandc_set_reg(nandc, NAND_FLASH_CMD, OP_FETCH_ID);
1271 	nandc_set_reg(nandc, NAND_ADDR0, column);
1272 	nandc_set_reg(nandc, NAND_ADDR1, 0);
1273 	nandc_set_reg(nandc, NAND_FLASH_CHIP_SELECT,
1274 		      nandc->props->is_bam ? 0 : DM_EN);
1275 	nandc_set_reg(nandc, NAND_EXEC_CMD, 1);
1276 
1277 	write_reg_dma(nandc, NAND_FLASH_CMD, 4, NAND_BAM_NEXT_SGL);
1278 	write_reg_dma(nandc, NAND_EXEC_CMD, 1, NAND_BAM_NEXT_SGL);
1279 
1280 	read_reg_dma(nandc, NAND_READ_ID, 1, NAND_BAM_NEXT_SGL);
1281 
1282 	return 0;
1283 }
1284 
1285 /* sets up descriptors for NAND_CMD_RESET */
1286 static int reset(struct qcom_nand_host *host)
1287 {
1288 	struct nand_chip *chip = &host->chip;
1289 	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
1290 
1291 	nandc_set_reg(nandc, NAND_FLASH_CMD, OP_RESET_DEVICE);
1292 	nandc_set_reg(nandc, NAND_EXEC_CMD, 1);
1293 
1294 	write_reg_dma(nandc, NAND_FLASH_CMD, 1, NAND_BAM_NEXT_SGL);
1295 	write_reg_dma(nandc, NAND_EXEC_CMD, 1, NAND_BAM_NEXT_SGL);
1296 
1297 	read_reg_dma(nandc, NAND_FLASH_STATUS, 1, NAND_BAM_NEXT_SGL);
1298 
1299 	return 0;
1300 }
1301 
1302 /* helpers to submit/free our list of dma descriptors */
1303 static int submit_descs(struct qcom_nand_controller *nandc)
1304 {
1305 	struct desc_info *desc;
1306 	dma_cookie_t cookie = 0;
1307 	struct bam_transaction *bam_txn = nandc->bam_txn;
1308 	int r;
1309 
1310 	if (nandc->props->is_bam) {
1311 		if (bam_txn->rx_sgl_pos > bam_txn->rx_sgl_start) {
1312 			r = prepare_bam_async_desc(nandc, nandc->rx_chan, 0);
1313 			if (r)
1314 				return r;
1315 		}
1316 
1317 		if (bam_txn->tx_sgl_pos > bam_txn->tx_sgl_start) {
1318 			r = prepare_bam_async_desc(nandc, nandc->tx_chan,
1319 						   DMA_PREP_INTERRUPT);
1320 			if (r)
1321 				return r;
1322 		}
1323 
1324 		if (bam_txn->cmd_sgl_pos > bam_txn->cmd_sgl_start) {
1325 			r = prepare_bam_async_desc(nandc, nandc->cmd_chan,
1326 						   DMA_PREP_CMD);
1327 			if (r)
1328 				return r;
1329 		}
1330 	}
1331 
1332 	list_for_each_entry(desc, &nandc->desc_list, node)
1333 		cookie = dmaengine_submit(desc->dma_desc);
1334 
1335 	if (nandc->props->is_bam) {
1336 		bam_txn->last_cmd_desc->callback = qpic_bam_dma_done;
1337 		bam_txn->last_cmd_desc->callback_param = bam_txn;
1338 		if (bam_txn->last_data_desc) {
1339 			bam_txn->last_data_desc->callback = qpic_bam_dma_done;
1340 			bam_txn->last_data_desc->callback_param = bam_txn;
1341 			bam_txn->wait_second_completion = true;
1342 		}
1343 
1344 		dma_async_issue_pending(nandc->tx_chan);
1345 		dma_async_issue_pending(nandc->rx_chan);
1346 		dma_async_issue_pending(nandc->cmd_chan);
1347 
1348 		if (!wait_for_completion_timeout(&bam_txn->txn_done,
1349 						 QPIC_NAND_COMPLETION_TIMEOUT))
1350 			return -ETIMEDOUT;
1351 	} else {
1352 		if (dma_sync_wait(nandc->chan, cookie) != DMA_COMPLETE)
1353 			return -ETIMEDOUT;
1354 	}
1355 
1356 	return 0;
1357 }
1358 
1359 static void free_descs(struct qcom_nand_controller *nandc)
1360 {
1361 	struct desc_info *desc, *n;
1362 
1363 	list_for_each_entry_safe(desc, n, &nandc->desc_list, node) {
1364 		list_del(&desc->node);
1365 
1366 		if (nandc->props->is_bam)
1367 			dma_unmap_sg(nandc->dev, desc->bam_sgl,
1368 				     desc->sgl_cnt, desc->dir);
1369 		else
1370 			dma_unmap_sg(nandc->dev, &desc->adm_sgl, 1,
1371 				     desc->dir);
1372 
1373 		kfree(desc);
1374 	}
1375 }
1376 
1377 /* reset the register read buffer for next NAND operation */
1378 static void clear_read_regs(struct qcom_nand_controller *nandc)
1379 {
1380 	nandc->reg_read_pos = 0;
1381 	nandc_read_buffer_sync(nandc, false);
1382 }
1383 
1384 static void pre_command(struct qcom_nand_host *host, int command)
1385 {
1386 	struct nand_chip *chip = &host->chip;
1387 	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
1388 
1389 	nandc->buf_count = 0;
1390 	nandc->buf_start = 0;
1391 	host->use_ecc = false;
1392 	host->last_command = command;
1393 
1394 	clear_read_regs(nandc);
1395 
1396 	if (command == NAND_CMD_RESET || command == NAND_CMD_READID ||
1397 	    command == NAND_CMD_PARAM || command == NAND_CMD_ERASE1)
1398 		clear_bam_transaction(nandc);
1399 }
1400 
1401 /*
1402  * this is called after NAND_CMD_PAGEPROG and NAND_CMD_ERASE1 to set our
1403  * privately maintained status byte, this status byte can be read after
1404  * NAND_CMD_STATUS is called
1405  */
1406 static void parse_erase_write_errors(struct qcom_nand_host *host, int command)
1407 {
1408 	struct nand_chip *chip = &host->chip;
1409 	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
1410 	struct nand_ecc_ctrl *ecc = &chip->ecc;
1411 	int num_cw;
1412 	int i;
1413 
1414 	num_cw = command == NAND_CMD_PAGEPROG ? ecc->steps : 1;
1415 	nandc_read_buffer_sync(nandc, true);
1416 
1417 	for (i = 0; i < num_cw; i++) {
1418 		u32 flash_status = le32_to_cpu(nandc->reg_read_buf[i]);
1419 
1420 		if (flash_status & FS_MPU_ERR)
1421 			host->status &= ~NAND_STATUS_WP;
1422 
1423 		if (flash_status & FS_OP_ERR || (i == (num_cw - 1) &&
1424 						 (flash_status &
1425 						  FS_DEVICE_STS_ERR)))
1426 			host->status |= NAND_STATUS_FAIL;
1427 	}
1428 }
1429 
1430 static void post_command(struct qcom_nand_host *host, int command)
1431 {
1432 	struct nand_chip *chip = &host->chip;
1433 	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
1434 
1435 	switch (command) {
1436 	case NAND_CMD_READID:
1437 		nandc_read_buffer_sync(nandc, true);
1438 		memcpy(nandc->data_buffer, nandc->reg_read_buf,
1439 		       nandc->buf_count);
1440 		break;
1441 	case NAND_CMD_PAGEPROG:
1442 	case NAND_CMD_ERASE1:
1443 		parse_erase_write_errors(host, command);
1444 		break;
1445 	default:
1446 		break;
1447 	}
1448 }
1449 
1450 /*
1451  * Implements chip->legacy.cmdfunc. It's  only used for a limited set of
1452  * commands. The rest of the commands wouldn't be called by upper layers.
1453  * For example, NAND_CMD_READOOB would never be called because we have our own
1454  * versions of read_oob ops for nand_ecc_ctrl.
1455  */
1456 static void qcom_nandc_command(struct nand_chip *chip, unsigned int command,
1457 			       int column, int page_addr)
1458 {
1459 	struct qcom_nand_host *host = to_qcom_nand_host(chip);
1460 	struct nand_ecc_ctrl *ecc = &chip->ecc;
1461 	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
1462 	bool wait = false;
1463 	int ret = 0;
1464 
1465 	pre_command(host, command);
1466 
1467 	switch (command) {
1468 	case NAND_CMD_RESET:
1469 		ret = reset(host);
1470 		wait = true;
1471 		break;
1472 
1473 	case NAND_CMD_READID:
1474 		nandc->buf_count = 4;
1475 		ret = read_id(host, column);
1476 		wait = true;
1477 		break;
1478 
1479 	case NAND_CMD_PARAM:
1480 		ret = nandc_param(host);
1481 		wait = true;
1482 		break;
1483 
1484 	case NAND_CMD_ERASE1:
1485 		ret = erase_block(host, page_addr);
1486 		wait = true;
1487 		break;
1488 
1489 	case NAND_CMD_READ0:
1490 		/* we read the entire page for now */
1491 		WARN_ON(column != 0);
1492 
1493 		host->use_ecc = true;
1494 		set_address(host, 0, page_addr);
1495 		update_rw_regs(host, ecc->steps, true);
1496 		break;
1497 
1498 	case NAND_CMD_SEQIN:
1499 		WARN_ON(column != 0);
1500 		set_address(host, 0, page_addr);
1501 		break;
1502 
1503 	case NAND_CMD_PAGEPROG:
1504 	case NAND_CMD_STATUS:
1505 	case NAND_CMD_NONE:
1506 	default:
1507 		break;
1508 	}
1509 
1510 	if (ret) {
1511 		dev_err(nandc->dev, "failure executing command %d\n",
1512 			command);
1513 		free_descs(nandc);
1514 		return;
1515 	}
1516 
1517 	if (wait) {
1518 		ret = submit_descs(nandc);
1519 		if (ret)
1520 			dev_err(nandc->dev,
1521 				"failure submitting descs for command %d\n",
1522 				command);
1523 	}
1524 
1525 	free_descs(nandc);
1526 
1527 	post_command(host, command);
1528 }
1529 
1530 /*
1531  * when using BCH ECC, the HW flags an error in NAND_FLASH_STATUS if it read
1532  * an erased CW, and reports an erased CW in NAND_ERASED_CW_DETECT_STATUS.
1533  *
1534  * when using RS ECC, the HW reports the same erros when reading an erased CW,
1535  * but it notifies that it is an erased CW by placing special characters at
1536  * certain offsets in the buffer.
1537  *
1538  * verify if the page is erased or not, and fix up the page for RS ECC by
1539  * replacing the special characters with 0xff.
1540  */
1541 static bool erased_chunk_check_and_fixup(u8 *data_buf, int data_len)
1542 {
1543 	u8 empty1, empty2;
1544 
1545 	/*
1546 	 * an erased page flags an error in NAND_FLASH_STATUS, check if the page
1547 	 * is erased by looking for 0x54s at offsets 3 and 175 from the
1548 	 * beginning of each codeword
1549 	 */
1550 
1551 	empty1 = data_buf[3];
1552 	empty2 = data_buf[175];
1553 
1554 	/*
1555 	 * if the erased codework markers, if they exist override them with
1556 	 * 0xffs
1557 	 */
1558 	if ((empty1 == 0x54 && empty2 == 0xff) ||
1559 	    (empty1 == 0xff && empty2 == 0x54)) {
1560 		data_buf[3] = 0xff;
1561 		data_buf[175] = 0xff;
1562 	}
1563 
1564 	/*
1565 	 * check if the entire chunk contains 0xffs or not. if it doesn't, then
1566 	 * restore the original values at the special offsets
1567 	 */
1568 	if (memchr_inv(data_buf, 0xff, data_len)) {
1569 		data_buf[3] = empty1;
1570 		data_buf[175] = empty2;
1571 
1572 		return false;
1573 	}
1574 
1575 	return true;
1576 }
1577 
1578 struct read_stats {
1579 	__le32 flash;
1580 	__le32 buffer;
1581 	__le32 erased_cw;
1582 };
1583 
1584 /* reads back FLASH_STATUS register set by the controller */
1585 static int check_flash_errors(struct qcom_nand_host *host, int cw_cnt)
1586 {
1587 	struct nand_chip *chip = &host->chip;
1588 	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
1589 	int i;
1590 
1591 	nandc_read_buffer_sync(nandc, true);
1592 
1593 	for (i = 0; i < cw_cnt; i++) {
1594 		u32 flash = le32_to_cpu(nandc->reg_read_buf[i]);
1595 
1596 		if (flash & (FS_OP_ERR | FS_MPU_ERR))
1597 			return -EIO;
1598 	}
1599 
1600 	return 0;
1601 }
1602 
1603 /* performs raw read for one codeword */
1604 static int
1605 qcom_nandc_read_cw_raw(struct mtd_info *mtd, struct nand_chip *chip,
1606 		       u8 *data_buf, u8 *oob_buf, int page, int cw)
1607 {
1608 	struct qcom_nand_host *host = to_qcom_nand_host(chip);
1609 	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
1610 	struct nand_ecc_ctrl *ecc = &chip->ecc;
1611 	int data_size1, data_size2, oob_size1, oob_size2;
1612 	int ret, reg_off = FLASH_BUF_ACC, read_loc = 0;
1613 
1614 	nand_read_page_op(chip, page, 0, NULL, 0);
1615 	host->use_ecc = false;
1616 
1617 	clear_bam_transaction(nandc);
1618 	set_address(host, host->cw_size * cw, page);
1619 	update_rw_regs(host, 1, true);
1620 	config_nand_page_read(nandc);
1621 
1622 	data_size1 = mtd->writesize - host->cw_size * (ecc->steps - 1);
1623 	oob_size1 = host->bbm_size;
1624 
1625 	if (cw == (ecc->steps - 1)) {
1626 		data_size2 = ecc->size - data_size1 -
1627 			     ((ecc->steps - 1) * 4);
1628 		oob_size2 = (ecc->steps * 4) + host->ecc_bytes_hw +
1629 			    host->spare_bytes;
1630 	} else {
1631 		data_size2 = host->cw_data - data_size1;
1632 		oob_size2 = host->ecc_bytes_hw + host->spare_bytes;
1633 	}
1634 
1635 	if (nandc->props->is_bam) {
1636 		nandc_set_read_loc(nandc, 0, read_loc, data_size1, 0);
1637 		read_loc += data_size1;
1638 
1639 		nandc_set_read_loc(nandc, 1, read_loc, oob_size1, 0);
1640 		read_loc += oob_size1;
1641 
1642 		nandc_set_read_loc(nandc, 2, read_loc, data_size2, 0);
1643 		read_loc += data_size2;
1644 
1645 		nandc_set_read_loc(nandc, 3, read_loc, oob_size2, 1);
1646 	}
1647 
1648 	config_nand_cw_read(nandc, false);
1649 
1650 	read_data_dma(nandc, reg_off, data_buf, data_size1, 0);
1651 	reg_off += data_size1;
1652 
1653 	read_data_dma(nandc, reg_off, oob_buf, oob_size1, 0);
1654 	reg_off += oob_size1;
1655 
1656 	read_data_dma(nandc, reg_off, data_buf + data_size1, data_size2, 0);
1657 	reg_off += data_size2;
1658 
1659 	read_data_dma(nandc, reg_off, oob_buf + oob_size1, oob_size2, 0);
1660 
1661 	ret = submit_descs(nandc);
1662 	free_descs(nandc);
1663 	if (ret) {
1664 		dev_err(nandc->dev, "failure to read raw cw %d\n", cw);
1665 		return ret;
1666 	}
1667 
1668 	return check_flash_errors(host, 1);
1669 }
1670 
1671 /*
1672  * Bitflips can happen in erased codewords also so this function counts the
1673  * number of 0 in each CW for which ECC engine returns the uncorrectable
1674  * error. The page will be assumed as erased if this count is less than or
1675  * equal to the ecc->strength for each CW.
1676  *
1677  * 1. Both DATA and OOB need to be checked for number of 0. The
1678  *    top-level API can be called with only data buf or OOB buf so use
1679  *    chip->data_buf if data buf is null and chip->oob_poi if oob buf
1680  *    is null for copying the raw bytes.
1681  * 2. Perform raw read for all the CW which has uncorrectable errors.
1682  * 3. For each CW, check the number of 0 in cw_data and usable OOB bytes.
1683  *    The BBM and spare bytes bit flip won’t affect the ECC so don’t check
1684  *    the number of bitflips in this area.
1685  */
1686 static int
1687 check_for_erased_page(struct qcom_nand_host *host, u8 *data_buf,
1688 		      u8 *oob_buf, unsigned long uncorrectable_cws,
1689 		      int page, unsigned int max_bitflips)
1690 {
1691 	struct nand_chip *chip = &host->chip;
1692 	struct mtd_info *mtd = nand_to_mtd(chip);
1693 	struct nand_ecc_ctrl *ecc = &chip->ecc;
1694 	u8 *cw_data_buf, *cw_oob_buf;
1695 	int cw, data_size, oob_size, ret = 0;
1696 
1697 	if (!data_buf)
1698 		data_buf = nand_get_data_buf(chip);
1699 
1700 	if (!oob_buf) {
1701 		nand_get_data_buf(chip);
1702 		oob_buf = chip->oob_poi;
1703 	}
1704 
1705 	for_each_set_bit(cw, &uncorrectable_cws, ecc->steps) {
1706 		if (cw == (ecc->steps - 1)) {
1707 			data_size = ecc->size - ((ecc->steps - 1) * 4);
1708 			oob_size = (ecc->steps * 4) + host->ecc_bytes_hw;
1709 		} else {
1710 			data_size = host->cw_data;
1711 			oob_size = host->ecc_bytes_hw;
1712 		}
1713 
1714 		/* determine starting buffer address for current CW */
1715 		cw_data_buf = data_buf + (cw * host->cw_data);
1716 		cw_oob_buf = oob_buf + (cw * ecc->bytes);
1717 
1718 		ret = qcom_nandc_read_cw_raw(mtd, chip, cw_data_buf,
1719 					     cw_oob_buf, page, cw);
1720 		if (ret)
1721 			return ret;
1722 
1723 		/*
1724 		 * make sure it isn't an erased page reported
1725 		 * as not-erased by HW because of a few bitflips
1726 		 */
1727 		ret = nand_check_erased_ecc_chunk(cw_data_buf, data_size,
1728 						  cw_oob_buf + host->bbm_size,
1729 						  oob_size, NULL,
1730 						  0, ecc->strength);
1731 		if (ret < 0) {
1732 			mtd->ecc_stats.failed++;
1733 		} else {
1734 			mtd->ecc_stats.corrected += ret;
1735 			max_bitflips = max_t(unsigned int, max_bitflips, ret);
1736 		}
1737 	}
1738 
1739 	return max_bitflips;
1740 }
1741 
1742 /*
1743  * reads back status registers set by the controller to notify page read
1744  * errors. this is equivalent to what 'ecc->correct()' would do.
1745  */
1746 static int parse_read_errors(struct qcom_nand_host *host, u8 *data_buf,
1747 			     u8 *oob_buf, int page)
1748 {
1749 	struct nand_chip *chip = &host->chip;
1750 	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
1751 	struct mtd_info *mtd = nand_to_mtd(chip);
1752 	struct nand_ecc_ctrl *ecc = &chip->ecc;
1753 	unsigned int max_bitflips = 0, uncorrectable_cws = 0;
1754 	struct read_stats *buf;
1755 	bool flash_op_err = false, erased;
1756 	int i;
1757 	u8 *data_buf_start = data_buf, *oob_buf_start = oob_buf;
1758 
1759 	buf = (struct read_stats *)nandc->reg_read_buf;
1760 	nandc_read_buffer_sync(nandc, true);
1761 
1762 	for (i = 0; i < ecc->steps; i++, buf++) {
1763 		u32 flash, buffer, erased_cw;
1764 		int data_len, oob_len;
1765 
1766 		if (i == (ecc->steps - 1)) {
1767 			data_len = ecc->size - ((ecc->steps - 1) << 2);
1768 			oob_len = ecc->steps << 2;
1769 		} else {
1770 			data_len = host->cw_data;
1771 			oob_len = 0;
1772 		}
1773 
1774 		flash = le32_to_cpu(buf->flash);
1775 		buffer = le32_to_cpu(buf->buffer);
1776 		erased_cw = le32_to_cpu(buf->erased_cw);
1777 
1778 		/*
1779 		 * Check ECC failure for each codeword. ECC failure can
1780 		 * happen in either of the following conditions
1781 		 * 1. If number of bitflips are greater than ECC engine
1782 		 *    capability.
1783 		 * 2. If this codeword contains all 0xff for which erased
1784 		 *    codeword detection check will be done.
1785 		 */
1786 		if ((flash & FS_OP_ERR) && (buffer & BS_UNCORRECTABLE_BIT)) {
1787 			/*
1788 			 * For BCH ECC, ignore erased codeword errors, if
1789 			 * ERASED_CW bits are set.
1790 			 */
1791 			if (host->bch_enabled) {
1792 				erased = (erased_cw & ERASED_CW) == ERASED_CW ?
1793 					 true : false;
1794 			/*
1795 			 * For RS ECC, HW reports the erased CW by placing
1796 			 * special characters at certain offsets in the buffer.
1797 			 * These special characters will be valid only if
1798 			 * complete page is read i.e. data_buf is not NULL.
1799 			 */
1800 			} else if (data_buf) {
1801 				erased = erased_chunk_check_and_fixup(data_buf,
1802 								      data_len);
1803 			} else {
1804 				erased = false;
1805 			}
1806 
1807 			if (!erased)
1808 				uncorrectable_cws |= BIT(i);
1809 		/*
1810 		 * Check if MPU or any other operational error (timeout,
1811 		 * device failure, etc.) happened for this codeword and
1812 		 * make flash_op_err true. If flash_op_err is set, then
1813 		 * EIO will be returned for page read.
1814 		 */
1815 		} else if (flash & (FS_OP_ERR | FS_MPU_ERR)) {
1816 			flash_op_err = true;
1817 		/*
1818 		 * No ECC or operational errors happened. Check the number of
1819 		 * bits corrected and update the ecc_stats.corrected.
1820 		 */
1821 		} else {
1822 			unsigned int stat;
1823 
1824 			stat = buffer & BS_CORRECTABLE_ERR_MSK;
1825 			mtd->ecc_stats.corrected += stat;
1826 			max_bitflips = max(max_bitflips, stat);
1827 		}
1828 
1829 		if (data_buf)
1830 			data_buf += data_len;
1831 		if (oob_buf)
1832 			oob_buf += oob_len + ecc->bytes;
1833 	}
1834 
1835 	if (flash_op_err)
1836 		return -EIO;
1837 
1838 	if (!uncorrectable_cws)
1839 		return max_bitflips;
1840 
1841 	return check_for_erased_page(host, data_buf_start, oob_buf_start,
1842 				     uncorrectable_cws, page,
1843 				     max_bitflips);
1844 }
1845 
1846 /*
1847  * helper to perform the actual page read operation, used by ecc->read_page(),
1848  * ecc->read_oob()
1849  */
1850 static int read_page_ecc(struct qcom_nand_host *host, u8 *data_buf,
1851 			 u8 *oob_buf, int page)
1852 {
1853 	struct nand_chip *chip = &host->chip;
1854 	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
1855 	struct nand_ecc_ctrl *ecc = &chip->ecc;
1856 	u8 *data_buf_start = data_buf, *oob_buf_start = oob_buf;
1857 	int i, ret;
1858 
1859 	config_nand_page_read(nandc);
1860 
1861 	/* queue cmd descs for each codeword */
1862 	for (i = 0; i < ecc->steps; i++) {
1863 		int data_size, oob_size;
1864 
1865 		if (i == (ecc->steps - 1)) {
1866 			data_size = ecc->size - ((ecc->steps - 1) << 2);
1867 			oob_size = (ecc->steps << 2) + host->ecc_bytes_hw +
1868 				   host->spare_bytes;
1869 		} else {
1870 			data_size = host->cw_data;
1871 			oob_size = host->ecc_bytes_hw + host->spare_bytes;
1872 		}
1873 
1874 		if (nandc->props->is_bam) {
1875 			if (data_buf && oob_buf) {
1876 				nandc_set_read_loc(nandc, 0, 0, data_size, 0);
1877 				nandc_set_read_loc(nandc, 1, data_size,
1878 						   oob_size, 1);
1879 			} else if (data_buf) {
1880 				nandc_set_read_loc(nandc, 0, 0, data_size, 1);
1881 			} else {
1882 				nandc_set_read_loc(nandc, 0, data_size,
1883 						   oob_size, 1);
1884 			}
1885 		}
1886 
1887 		config_nand_cw_read(nandc, true);
1888 
1889 		if (data_buf)
1890 			read_data_dma(nandc, FLASH_BUF_ACC, data_buf,
1891 				      data_size, 0);
1892 
1893 		/*
1894 		 * when ecc is enabled, the controller doesn't read the real
1895 		 * or dummy bad block markers in each chunk. To maintain a
1896 		 * consistent layout across RAW and ECC reads, we just
1897 		 * leave the real/dummy BBM offsets empty (i.e, filled with
1898 		 * 0xffs)
1899 		 */
1900 		if (oob_buf) {
1901 			int j;
1902 
1903 			for (j = 0; j < host->bbm_size; j++)
1904 				*oob_buf++ = 0xff;
1905 
1906 			read_data_dma(nandc, FLASH_BUF_ACC + data_size,
1907 				      oob_buf, oob_size, 0);
1908 		}
1909 
1910 		if (data_buf)
1911 			data_buf += data_size;
1912 		if (oob_buf)
1913 			oob_buf += oob_size;
1914 	}
1915 
1916 	ret = submit_descs(nandc);
1917 	free_descs(nandc);
1918 
1919 	if (ret) {
1920 		dev_err(nandc->dev, "failure to read page/oob\n");
1921 		return ret;
1922 	}
1923 
1924 	return parse_read_errors(host, data_buf_start, oob_buf_start, page);
1925 }
1926 
1927 /*
1928  * a helper that copies the last step/codeword of a page (containing free oob)
1929  * into our local buffer
1930  */
1931 static int copy_last_cw(struct qcom_nand_host *host, int page)
1932 {
1933 	struct nand_chip *chip = &host->chip;
1934 	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
1935 	struct nand_ecc_ctrl *ecc = &chip->ecc;
1936 	int size;
1937 	int ret;
1938 
1939 	clear_read_regs(nandc);
1940 
1941 	size = host->use_ecc ? host->cw_data : host->cw_size;
1942 
1943 	/* prepare a clean read buffer */
1944 	memset(nandc->data_buffer, 0xff, size);
1945 
1946 	set_address(host, host->cw_size * (ecc->steps - 1), page);
1947 	update_rw_regs(host, 1, true);
1948 
1949 	config_nand_single_cw_page_read(nandc, host->use_ecc);
1950 
1951 	read_data_dma(nandc, FLASH_BUF_ACC, nandc->data_buffer, size, 0);
1952 
1953 	ret = submit_descs(nandc);
1954 	if (ret)
1955 		dev_err(nandc->dev, "failed to copy last codeword\n");
1956 
1957 	free_descs(nandc);
1958 
1959 	return ret;
1960 }
1961 
1962 /* implements ecc->read_page() */
1963 static int qcom_nandc_read_page(struct nand_chip *chip, uint8_t *buf,
1964 				int oob_required, int page)
1965 {
1966 	struct qcom_nand_host *host = to_qcom_nand_host(chip);
1967 	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
1968 	u8 *data_buf, *oob_buf = NULL;
1969 
1970 	nand_read_page_op(chip, page, 0, NULL, 0);
1971 	data_buf = buf;
1972 	oob_buf = oob_required ? chip->oob_poi : NULL;
1973 
1974 	clear_bam_transaction(nandc);
1975 
1976 	return read_page_ecc(host, data_buf, oob_buf, page);
1977 }
1978 
1979 /* implements ecc->read_page_raw() */
1980 static int qcom_nandc_read_page_raw(struct nand_chip *chip, uint8_t *buf,
1981 				    int oob_required, int page)
1982 {
1983 	struct mtd_info *mtd = nand_to_mtd(chip);
1984 	struct qcom_nand_host *host = to_qcom_nand_host(chip);
1985 	struct nand_ecc_ctrl *ecc = &chip->ecc;
1986 	int cw, ret;
1987 	u8 *data_buf = buf, *oob_buf = chip->oob_poi;
1988 
1989 	for (cw = 0; cw < ecc->steps; cw++) {
1990 		ret = qcom_nandc_read_cw_raw(mtd, chip, data_buf, oob_buf,
1991 					     page, cw);
1992 		if (ret)
1993 			return ret;
1994 
1995 		data_buf += host->cw_data;
1996 		oob_buf += ecc->bytes;
1997 	}
1998 
1999 	return 0;
2000 }
2001 
2002 /* implements ecc->read_oob() */
2003 static int qcom_nandc_read_oob(struct nand_chip *chip, int page)
2004 {
2005 	struct qcom_nand_host *host = to_qcom_nand_host(chip);
2006 	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
2007 	struct nand_ecc_ctrl *ecc = &chip->ecc;
2008 
2009 	clear_read_regs(nandc);
2010 	clear_bam_transaction(nandc);
2011 
2012 	host->use_ecc = true;
2013 	set_address(host, 0, page);
2014 	update_rw_regs(host, ecc->steps, true);
2015 
2016 	return read_page_ecc(host, NULL, chip->oob_poi, page);
2017 }
2018 
2019 /* implements ecc->write_page() */
2020 static int qcom_nandc_write_page(struct nand_chip *chip, const uint8_t *buf,
2021 				 int oob_required, int page)
2022 {
2023 	struct qcom_nand_host *host = to_qcom_nand_host(chip);
2024 	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
2025 	struct nand_ecc_ctrl *ecc = &chip->ecc;
2026 	u8 *data_buf, *oob_buf;
2027 	int i, ret;
2028 
2029 	nand_prog_page_begin_op(chip, page, 0, NULL, 0);
2030 
2031 	clear_read_regs(nandc);
2032 	clear_bam_transaction(nandc);
2033 
2034 	data_buf = (u8 *)buf;
2035 	oob_buf = chip->oob_poi;
2036 
2037 	host->use_ecc = true;
2038 	update_rw_regs(host, ecc->steps, false);
2039 	config_nand_page_write(nandc);
2040 
2041 	for (i = 0; i < ecc->steps; i++) {
2042 		int data_size, oob_size;
2043 
2044 		if (i == (ecc->steps - 1)) {
2045 			data_size = ecc->size - ((ecc->steps - 1) << 2);
2046 			oob_size = (ecc->steps << 2) + host->ecc_bytes_hw +
2047 				   host->spare_bytes;
2048 		} else {
2049 			data_size = host->cw_data;
2050 			oob_size = ecc->bytes;
2051 		}
2052 
2053 
2054 		write_data_dma(nandc, FLASH_BUF_ACC, data_buf, data_size,
2055 			       i == (ecc->steps - 1) ? NAND_BAM_NO_EOT : 0);
2056 
2057 		/*
2058 		 * when ECC is enabled, we don't really need to write anything
2059 		 * to oob for the first n - 1 codewords since these oob regions
2060 		 * just contain ECC bytes that's written by the controller
2061 		 * itself. For the last codeword, we skip the bbm positions and
2062 		 * write to the free oob area.
2063 		 */
2064 		if (i == (ecc->steps - 1)) {
2065 			oob_buf += host->bbm_size;
2066 
2067 			write_data_dma(nandc, FLASH_BUF_ACC + data_size,
2068 				       oob_buf, oob_size, 0);
2069 		}
2070 
2071 		config_nand_cw_write(nandc);
2072 
2073 		data_buf += data_size;
2074 		oob_buf += oob_size;
2075 	}
2076 
2077 	ret = submit_descs(nandc);
2078 	if (ret)
2079 		dev_err(nandc->dev, "failure to write page\n");
2080 
2081 	free_descs(nandc);
2082 
2083 	if (!ret)
2084 		ret = nand_prog_page_end_op(chip);
2085 
2086 	return ret;
2087 }
2088 
2089 /* implements ecc->write_page_raw() */
2090 static int qcom_nandc_write_page_raw(struct nand_chip *chip,
2091 				     const uint8_t *buf, int oob_required,
2092 				     int page)
2093 {
2094 	struct mtd_info *mtd = nand_to_mtd(chip);
2095 	struct qcom_nand_host *host = to_qcom_nand_host(chip);
2096 	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
2097 	struct nand_ecc_ctrl *ecc = &chip->ecc;
2098 	u8 *data_buf, *oob_buf;
2099 	int i, ret;
2100 
2101 	nand_prog_page_begin_op(chip, page, 0, NULL, 0);
2102 	clear_read_regs(nandc);
2103 	clear_bam_transaction(nandc);
2104 
2105 	data_buf = (u8 *)buf;
2106 	oob_buf = chip->oob_poi;
2107 
2108 	host->use_ecc = false;
2109 	update_rw_regs(host, ecc->steps, false);
2110 	config_nand_page_write(nandc);
2111 
2112 	for (i = 0; i < ecc->steps; i++) {
2113 		int data_size1, data_size2, oob_size1, oob_size2;
2114 		int reg_off = FLASH_BUF_ACC;
2115 
2116 		data_size1 = mtd->writesize - host->cw_size * (ecc->steps - 1);
2117 		oob_size1 = host->bbm_size;
2118 
2119 		if (i == (ecc->steps - 1)) {
2120 			data_size2 = ecc->size - data_size1 -
2121 				     ((ecc->steps - 1) << 2);
2122 			oob_size2 = (ecc->steps << 2) + host->ecc_bytes_hw +
2123 				    host->spare_bytes;
2124 		} else {
2125 			data_size2 = host->cw_data - data_size1;
2126 			oob_size2 = host->ecc_bytes_hw + host->spare_bytes;
2127 		}
2128 
2129 		write_data_dma(nandc, reg_off, data_buf, data_size1,
2130 			       NAND_BAM_NO_EOT);
2131 		reg_off += data_size1;
2132 		data_buf += data_size1;
2133 
2134 		write_data_dma(nandc, reg_off, oob_buf, oob_size1,
2135 			       NAND_BAM_NO_EOT);
2136 		reg_off += oob_size1;
2137 		oob_buf += oob_size1;
2138 
2139 		write_data_dma(nandc, reg_off, data_buf, data_size2,
2140 			       NAND_BAM_NO_EOT);
2141 		reg_off += data_size2;
2142 		data_buf += data_size2;
2143 
2144 		write_data_dma(nandc, reg_off, oob_buf, oob_size2, 0);
2145 		oob_buf += oob_size2;
2146 
2147 		config_nand_cw_write(nandc);
2148 	}
2149 
2150 	ret = submit_descs(nandc);
2151 	if (ret)
2152 		dev_err(nandc->dev, "failure to write raw page\n");
2153 
2154 	free_descs(nandc);
2155 
2156 	if (!ret)
2157 		ret = nand_prog_page_end_op(chip);
2158 
2159 	return ret;
2160 }
2161 
2162 /*
2163  * implements ecc->write_oob()
2164  *
2165  * the NAND controller cannot write only data or only OOB within a codeword
2166  * since ECC is calculated for the combined codeword. So update the OOB from
2167  * chip->oob_poi, and pad the data area with OxFF before writing.
2168  */
2169 static int qcom_nandc_write_oob(struct nand_chip *chip, int page)
2170 {
2171 	struct mtd_info *mtd = nand_to_mtd(chip);
2172 	struct qcom_nand_host *host = to_qcom_nand_host(chip);
2173 	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
2174 	struct nand_ecc_ctrl *ecc = &chip->ecc;
2175 	u8 *oob = chip->oob_poi;
2176 	int data_size, oob_size;
2177 	int ret;
2178 
2179 	host->use_ecc = true;
2180 	clear_bam_transaction(nandc);
2181 
2182 	/* calculate the data and oob size for the last codeword/step */
2183 	data_size = ecc->size - ((ecc->steps - 1) << 2);
2184 	oob_size = mtd->oobavail;
2185 
2186 	memset(nandc->data_buffer, 0xff, host->cw_data);
2187 	/* override new oob content to last codeword */
2188 	mtd_ooblayout_get_databytes(mtd, nandc->data_buffer + data_size, oob,
2189 				    0, mtd->oobavail);
2190 
2191 	set_address(host, host->cw_size * (ecc->steps - 1), page);
2192 	update_rw_regs(host, 1, false);
2193 
2194 	config_nand_page_write(nandc);
2195 	write_data_dma(nandc, FLASH_BUF_ACC,
2196 		       nandc->data_buffer, data_size + oob_size, 0);
2197 	config_nand_cw_write(nandc);
2198 
2199 	ret = submit_descs(nandc);
2200 
2201 	free_descs(nandc);
2202 
2203 	if (ret) {
2204 		dev_err(nandc->dev, "failure to write oob\n");
2205 		return -EIO;
2206 	}
2207 
2208 	return nand_prog_page_end_op(chip);
2209 }
2210 
2211 static int qcom_nandc_block_bad(struct nand_chip *chip, loff_t ofs)
2212 {
2213 	struct mtd_info *mtd = nand_to_mtd(chip);
2214 	struct qcom_nand_host *host = to_qcom_nand_host(chip);
2215 	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
2216 	struct nand_ecc_ctrl *ecc = &chip->ecc;
2217 	int page, ret, bbpos, bad = 0;
2218 
2219 	page = (int)(ofs >> chip->page_shift) & chip->pagemask;
2220 
2221 	/*
2222 	 * configure registers for a raw sub page read, the address is set to
2223 	 * the beginning of the last codeword, we don't care about reading ecc
2224 	 * portion of oob. we just want the first few bytes from this codeword
2225 	 * that contains the BBM
2226 	 */
2227 	host->use_ecc = false;
2228 
2229 	clear_bam_transaction(nandc);
2230 	ret = copy_last_cw(host, page);
2231 	if (ret)
2232 		goto err;
2233 
2234 	if (check_flash_errors(host, 1)) {
2235 		dev_warn(nandc->dev, "error when trying to read BBM\n");
2236 		goto err;
2237 	}
2238 
2239 	bbpos = mtd->writesize - host->cw_size * (ecc->steps - 1);
2240 
2241 	bad = nandc->data_buffer[bbpos] != 0xff;
2242 
2243 	if (chip->options & NAND_BUSWIDTH_16)
2244 		bad = bad || (nandc->data_buffer[bbpos + 1] != 0xff);
2245 err:
2246 	return bad;
2247 }
2248 
2249 static int qcom_nandc_block_markbad(struct nand_chip *chip, loff_t ofs)
2250 {
2251 	struct qcom_nand_host *host = to_qcom_nand_host(chip);
2252 	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
2253 	struct nand_ecc_ctrl *ecc = &chip->ecc;
2254 	int page, ret;
2255 
2256 	clear_read_regs(nandc);
2257 	clear_bam_transaction(nandc);
2258 
2259 	/*
2260 	 * to mark the BBM as bad, we flash the entire last codeword with 0s.
2261 	 * we don't care about the rest of the content in the codeword since
2262 	 * we aren't going to use this block again
2263 	 */
2264 	memset(nandc->data_buffer, 0x00, host->cw_size);
2265 
2266 	page = (int)(ofs >> chip->page_shift) & chip->pagemask;
2267 
2268 	/* prepare write */
2269 	host->use_ecc = false;
2270 	set_address(host, host->cw_size * (ecc->steps - 1), page);
2271 	update_rw_regs(host, 1, false);
2272 
2273 	config_nand_page_write(nandc);
2274 	write_data_dma(nandc, FLASH_BUF_ACC,
2275 		       nandc->data_buffer, host->cw_size, 0);
2276 	config_nand_cw_write(nandc);
2277 
2278 	ret = submit_descs(nandc);
2279 
2280 	free_descs(nandc);
2281 
2282 	if (ret) {
2283 		dev_err(nandc->dev, "failure to update BBM\n");
2284 		return -EIO;
2285 	}
2286 
2287 	return nand_prog_page_end_op(chip);
2288 }
2289 
2290 /*
2291  * the three functions below implement chip->legacy.read_byte(),
2292  * chip->legacy.read_buf() and chip->legacy.write_buf() respectively. these
2293  * aren't used for reading/writing page data, they are used for smaller data
2294  * like reading	id, status etc
2295  */
2296 static uint8_t qcom_nandc_read_byte(struct nand_chip *chip)
2297 {
2298 	struct qcom_nand_host *host = to_qcom_nand_host(chip);
2299 	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
2300 	u8 *buf = nandc->data_buffer;
2301 	u8 ret = 0x0;
2302 
2303 	if (host->last_command == NAND_CMD_STATUS) {
2304 		ret = host->status;
2305 
2306 		host->status = NAND_STATUS_READY | NAND_STATUS_WP;
2307 
2308 		return ret;
2309 	}
2310 
2311 	if (nandc->buf_start < nandc->buf_count)
2312 		ret = buf[nandc->buf_start++];
2313 
2314 	return ret;
2315 }
2316 
2317 static void qcom_nandc_read_buf(struct nand_chip *chip, uint8_t *buf, int len)
2318 {
2319 	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
2320 	int real_len = min_t(size_t, len, nandc->buf_count - nandc->buf_start);
2321 
2322 	memcpy(buf, nandc->data_buffer + nandc->buf_start, real_len);
2323 	nandc->buf_start += real_len;
2324 }
2325 
2326 static void qcom_nandc_write_buf(struct nand_chip *chip, const uint8_t *buf,
2327 				 int len)
2328 {
2329 	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
2330 	int real_len = min_t(size_t, len, nandc->buf_count - nandc->buf_start);
2331 
2332 	memcpy(nandc->data_buffer + nandc->buf_start, buf, real_len);
2333 
2334 	nandc->buf_start += real_len;
2335 }
2336 
2337 /* we support only one external chip for now */
2338 static void qcom_nandc_select_chip(struct nand_chip *chip, int chipnr)
2339 {
2340 	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
2341 
2342 	if (chipnr <= 0)
2343 		return;
2344 
2345 	dev_warn(nandc->dev, "invalid chip select\n");
2346 }
2347 
2348 /*
2349  * NAND controller page layout info
2350  *
2351  * Layout with ECC enabled:
2352  *
2353  * |----------------------|  |---------------------------------|
2354  * |           xx.......yy|  |             *********xx.......yy|
2355  * |    DATA   xx..ECC..yy|  |    DATA     **SPARE**xx..ECC..yy|
2356  * |   (516)   xx.......yy|  |  (516-n*4)  **(n*4)**xx.......yy|
2357  * |           xx.......yy|  |             *********xx.......yy|
2358  * |----------------------|  |---------------------------------|
2359  *     codeword 1,2..n-1                  codeword n
2360  *  <---(528/532 Bytes)-->    <-------(528/532 Bytes)--------->
2361  *
2362  * n = Number of codewords in the page
2363  * . = ECC bytes
2364  * * = Spare/free bytes
2365  * x = Unused byte(s)
2366  * y = Reserved byte(s)
2367  *
2368  * 2K page: n = 4, spare = 16 bytes
2369  * 4K page: n = 8, spare = 32 bytes
2370  * 8K page: n = 16, spare = 64 bytes
2371  *
2372  * the qcom nand controller operates at a sub page/codeword level. each
2373  * codeword is 528 and 532 bytes for 4 bit and 8 bit ECC modes respectively.
2374  * the number of ECC bytes vary based on the ECC strength and the bus width.
2375  *
2376  * the first n - 1 codewords contains 516 bytes of user data, the remaining
2377  * 12/16 bytes consist of ECC and reserved data. The nth codeword contains
2378  * both user data and spare(oobavail) bytes that sum up to 516 bytes.
2379  *
2380  * When we access a page with ECC enabled, the reserved bytes(s) are not
2381  * accessible at all. When reading, we fill up these unreadable positions
2382  * with 0xffs. When writing, the controller skips writing the inaccessible
2383  * bytes.
2384  *
2385  * Layout with ECC disabled:
2386  *
2387  * |------------------------------|  |---------------------------------------|
2388  * |         yy          xx.......|  |         bb          *********xx.......|
2389  * |  DATA1  yy  DATA2   xx..ECC..|  |  DATA1  bb  DATA2   **SPARE**xx..ECC..|
2390  * | (size1) yy (size2)  xx.......|  | (size1) bb (size2)  **(n*4)**xx.......|
2391  * |         yy          xx.......|  |         bb          *********xx.......|
2392  * |------------------------------|  |---------------------------------------|
2393  *         codeword 1,2..n-1                        codeword n
2394  *  <-------(528/532 Bytes)------>    <-----------(528/532 Bytes)----------->
2395  *
2396  * n = Number of codewords in the page
2397  * . = ECC bytes
2398  * * = Spare/free bytes
2399  * x = Unused byte(s)
2400  * y = Dummy Bad Bock byte(s)
2401  * b = Real Bad Block byte(s)
2402  * size1/size2 = function of codeword size and 'n'
2403  *
2404  * when the ECC block is disabled, one reserved byte (or two for 16 bit bus
2405  * width) is now accessible. For the first n - 1 codewords, these are dummy Bad
2406  * Block Markers. In the last codeword, this position contains the real BBM
2407  *
2408  * In order to have a consistent layout between RAW and ECC modes, we assume
2409  * the following OOB layout arrangement:
2410  *
2411  * |-----------|  |--------------------|
2412  * |yyxx.......|  |bb*********xx.......|
2413  * |yyxx..ECC..|  |bb*FREEOOB*xx..ECC..|
2414  * |yyxx.......|  |bb*********xx.......|
2415  * |yyxx.......|  |bb*********xx.......|
2416  * |-----------|  |--------------------|
2417  *  first n - 1       nth OOB region
2418  *  OOB regions
2419  *
2420  * n = Number of codewords in the page
2421  * . = ECC bytes
2422  * * = FREE OOB bytes
2423  * y = Dummy bad block byte(s) (inaccessible when ECC enabled)
2424  * x = Unused byte(s)
2425  * b = Real bad block byte(s) (inaccessible when ECC enabled)
2426  *
2427  * This layout is read as is when ECC is disabled. When ECC is enabled, the
2428  * inaccessible Bad Block byte(s) are ignored when we write to a page/oob,
2429  * and assumed as 0xffs when we read a page/oob. The ECC, unused and
2430  * dummy/real bad block bytes are grouped as ecc bytes (i.e, ecc->bytes is
2431  * the sum of the three).
2432  */
2433 static int qcom_nand_ooblayout_ecc(struct mtd_info *mtd, int section,
2434 				   struct mtd_oob_region *oobregion)
2435 {
2436 	struct nand_chip *chip = mtd_to_nand(mtd);
2437 	struct qcom_nand_host *host = to_qcom_nand_host(chip);
2438 	struct nand_ecc_ctrl *ecc = &chip->ecc;
2439 
2440 	if (section > 1)
2441 		return -ERANGE;
2442 
2443 	if (!section) {
2444 		oobregion->length = (ecc->bytes * (ecc->steps - 1)) +
2445 				    host->bbm_size;
2446 		oobregion->offset = 0;
2447 	} else {
2448 		oobregion->length = host->ecc_bytes_hw + host->spare_bytes;
2449 		oobregion->offset = mtd->oobsize - oobregion->length;
2450 	}
2451 
2452 	return 0;
2453 }
2454 
2455 static int qcom_nand_ooblayout_free(struct mtd_info *mtd, int section,
2456 				     struct mtd_oob_region *oobregion)
2457 {
2458 	struct nand_chip *chip = mtd_to_nand(mtd);
2459 	struct qcom_nand_host *host = to_qcom_nand_host(chip);
2460 	struct nand_ecc_ctrl *ecc = &chip->ecc;
2461 
2462 	if (section)
2463 		return -ERANGE;
2464 
2465 	oobregion->length = ecc->steps * 4;
2466 	oobregion->offset = ((ecc->steps - 1) * ecc->bytes) + host->bbm_size;
2467 
2468 	return 0;
2469 }
2470 
2471 static const struct mtd_ooblayout_ops qcom_nand_ooblayout_ops = {
2472 	.ecc = qcom_nand_ooblayout_ecc,
2473 	.free = qcom_nand_ooblayout_free,
2474 };
2475 
2476 static int
2477 qcom_nandc_calc_ecc_bytes(int step_size, int strength)
2478 {
2479 	return strength == 4 ? 12 : 16;
2480 }
2481 NAND_ECC_CAPS_SINGLE(qcom_nandc_ecc_caps, qcom_nandc_calc_ecc_bytes,
2482 		     NANDC_STEP_SIZE, 4, 8);
2483 
2484 static int qcom_nand_attach_chip(struct nand_chip *chip)
2485 {
2486 	struct mtd_info *mtd = nand_to_mtd(chip);
2487 	struct qcom_nand_host *host = to_qcom_nand_host(chip);
2488 	struct nand_ecc_ctrl *ecc = &chip->ecc;
2489 	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
2490 	int cwperpage, bad_block_byte, ret;
2491 	bool wide_bus;
2492 	int ecc_mode = 1;
2493 
2494 	/* controller only supports 512 bytes data steps */
2495 	ecc->size = NANDC_STEP_SIZE;
2496 	wide_bus = chip->options & NAND_BUSWIDTH_16 ? true : false;
2497 	cwperpage = mtd->writesize / NANDC_STEP_SIZE;
2498 
2499 	/*
2500 	 * Each CW has 4 available OOB bytes which will be protected with ECC
2501 	 * so remaining bytes can be used for ECC.
2502 	 */
2503 	ret = nand_ecc_choose_conf(chip, &qcom_nandc_ecc_caps,
2504 				   mtd->oobsize - (cwperpage * 4));
2505 	if (ret) {
2506 		dev_err(nandc->dev, "No valid ECC settings possible\n");
2507 		return ret;
2508 	}
2509 
2510 	if (ecc->strength >= 8) {
2511 		/* 8 bit ECC defaults to BCH ECC on all platforms */
2512 		host->bch_enabled = true;
2513 		ecc_mode = 1;
2514 
2515 		if (wide_bus) {
2516 			host->ecc_bytes_hw = 14;
2517 			host->spare_bytes = 0;
2518 			host->bbm_size = 2;
2519 		} else {
2520 			host->ecc_bytes_hw = 13;
2521 			host->spare_bytes = 2;
2522 			host->bbm_size = 1;
2523 		}
2524 	} else {
2525 		/*
2526 		 * if the controller supports BCH for 4 bit ECC, the controller
2527 		 * uses lesser bytes for ECC. If RS is used, the ECC bytes is
2528 		 * always 10 bytes
2529 		 */
2530 		if (nandc->props->ecc_modes & ECC_BCH_4BIT) {
2531 			/* BCH */
2532 			host->bch_enabled = true;
2533 			ecc_mode = 0;
2534 
2535 			if (wide_bus) {
2536 				host->ecc_bytes_hw = 8;
2537 				host->spare_bytes = 2;
2538 				host->bbm_size = 2;
2539 			} else {
2540 				host->ecc_bytes_hw = 7;
2541 				host->spare_bytes = 4;
2542 				host->bbm_size = 1;
2543 			}
2544 		} else {
2545 			/* RS */
2546 			host->ecc_bytes_hw = 10;
2547 
2548 			if (wide_bus) {
2549 				host->spare_bytes = 0;
2550 				host->bbm_size = 2;
2551 			} else {
2552 				host->spare_bytes = 1;
2553 				host->bbm_size = 1;
2554 			}
2555 		}
2556 	}
2557 
2558 	/*
2559 	 * we consider ecc->bytes as the sum of all the non-data content in a
2560 	 * step. It gives us a clean representation of the oob area (even if
2561 	 * all the bytes aren't used for ECC).It is always 16 bytes for 8 bit
2562 	 * ECC and 12 bytes for 4 bit ECC
2563 	 */
2564 	ecc->bytes = host->ecc_bytes_hw + host->spare_bytes + host->bbm_size;
2565 
2566 	ecc->read_page		= qcom_nandc_read_page;
2567 	ecc->read_page_raw	= qcom_nandc_read_page_raw;
2568 	ecc->read_oob		= qcom_nandc_read_oob;
2569 	ecc->write_page		= qcom_nandc_write_page;
2570 	ecc->write_page_raw	= qcom_nandc_write_page_raw;
2571 	ecc->write_oob		= qcom_nandc_write_oob;
2572 
2573 	ecc->engine_type = NAND_ECC_ENGINE_TYPE_ON_HOST;
2574 
2575 	mtd_set_ooblayout(mtd, &qcom_nand_ooblayout_ops);
2576 
2577 	nandc->max_cwperpage = max_t(unsigned int, nandc->max_cwperpage,
2578 				     cwperpage);
2579 
2580 	/*
2581 	 * DATA_UD_BYTES varies based on whether the read/write command protects
2582 	 * spare data with ECC too. We protect spare data by default, so we set
2583 	 * it to main + spare data, which are 512 and 4 bytes respectively.
2584 	 */
2585 	host->cw_data = 516;
2586 
2587 	/*
2588 	 * total bytes in a step, either 528 bytes for 4 bit ECC, or 532 bytes
2589 	 * for 8 bit ECC
2590 	 */
2591 	host->cw_size = host->cw_data + ecc->bytes;
2592 	bad_block_byte = mtd->writesize - host->cw_size * (cwperpage - 1) + 1;
2593 
2594 	host->cfg0 = (cwperpage - 1) << CW_PER_PAGE
2595 				| host->cw_data << UD_SIZE_BYTES
2596 				| 0 << DISABLE_STATUS_AFTER_WRITE
2597 				| 5 << NUM_ADDR_CYCLES
2598 				| host->ecc_bytes_hw << ECC_PARITY_SIZE_BYTES_RS
2599 				| 0 << STATUS_BFR_READ
2600 				| 1 << SET_RD_MODE_AFTER_STATUS
2601 				| host->spare_bytes << SPARE_SIZE_BYTES;
2602 
2603 	host->cfg1 = 7 << NAND_RECOVERY_CYCLES
2604 				| 0 <<  CS_ACTIVE_BSY
2605 				| bad_block_byte << BAD_BLOCK_BYTE_NUM
2606 				| 0 << BAD_BLOCK_IN_SPARE_AREA
2607 				| 2 << WR_RD_BSY_GAP
2608 				| wide_bus << WIDE_FLASH
2609 				| host->bch_enabled << ENABLE_BCH_ECC;
2610 
2611 	host->cfg0_raw = (cwperpage - 1) << CW_PER_PAGE
2612 				| host->cw_size << UD_SIZE_BYTES
2613 				| 5 << NUM_ADDR_CYCLES
2614 				| 0 << SPARE_SIZE_BYTES;
2615 
2616 	host->cfg1_raw = 7 << NAND_RECOVERY_CYCLES
2617 				| 0 << CS_ACTIVE_BSY
2618 				| 17 << BAD_BLOCK_BYTE_NUM
2619 				| 1 << BAD_BLOCK_IN_SPARE_AREA
2620 				| 2 << WR_RD_BSY_GAP
2621 				| wide_bus << WIDE_FLASH
2622 				| 1 << DEV0_CFG1_ECC_DISABLE;
2623 
2624 	host->ecc_bch_cfg = !host->bch_enabled << ECC_CFG_ECC_DISABLE
2625 				| 0 << ECC_SW_RESET
2626 				| host->cw_data << ECC_NUM_DATA_BYTES
2627 				| 1 << ECC_FORCE_CLK_OPEN
2628 				| ecc_mode << ECC_MODE
2629 				| host->ecc_bytes_hw << ECC_PARITY_SIZE_BYTES_BCH;
2630 
2631 	host->ecc_buf_cfg = 0x203 << NUM_STEPS;
2632 
2633 	host->clrflashstatus = FS_READY_BSY_N;
2634 	host->clrreadstatus = 0xc0;
2635 	nandc->regs->erased_cw_detect_cfg_clr =
2636 		cpu_to_le32(CLR_ERASED_PAGE_DET);
2637 	nandc->regs->erased_cw_detect_cfg_set =
2638 		cpu_to_le32(SET_ERASED_PAGE_DET);
2639 
2640 	dev_dbg(nandc->dev,
2641 		"cfg0 %x cfg1 %x ecc_buf_cfg %x ecc_bch cfg %x cw_size %d cw_data %d strength %d parity_bytes %d steps %d\n",
2642 		host->cfg0, host->cfg1, host->ecc_buf_cfg, host->ecc_bch_cfg,
2643 		host->cw_size, host->cw_data, ecc->strength, ecc->bytes,
2644 		cwperpage);
2645 
2646 	return 0;
2647 }
2648 
2649 static const struct nand_controller_ops qcom_nandc_ops = {
2650 	.attach_chip = qcom_nand_attach_chip,
2651 };
2652 
2653 static void qcom_nandc_unalloc(struct qcom_nand_controller *nandc)
2654 {
2655 	if (nandc->props->is_bam) {
2656 		if (!dma_mapping_error(nandc->dev, nandc->reg_read_dma))
2657 			dma_unmap_single(nandc->dev, nandc->reg_read_dma,
2658 					 MAX_REG_RD *
2659 					 sizeof(*nandc->reg_read_buf),
2660 					 DMA_FROM_DEVICE);
2661 
2662 		if (nandc->tx_chan)
2663 			dma_release_channel(nandc->tx_chan);
2664 
2665 		if (nandc->rx_chan)
2666 			dma_release_channel(nandc->rx_chan);
2667 
2668 		if (nandc->cmd_chan)
2669 			dma_release_channel(nandc->cmd_chan);
2670 	} else {
2671 		if (nandc->chan)
2672 			dma_release_channel(nandc->chan);
2673 	}
2674 }
2675 
2676 static int qcom_nandc_alloc(struct qcom_nand_controller *nandc)
2677 {
2678 	int ret;
2679 
2680 	ret = dma_set_coherent_mask(nandc->dev, DMA_BIT_MASK(32));
2681 	if (ret) {
2682 		dev_err(nandc->dev, "failed to set DMA mask\n");
2683 		return ret;
2684 	}
2685 
2686 	/*
2687 	 * we use the internal buffer for reading ONFI params, reading small
2688 	 * data like ID and status, and preforming read-copy-write operations
2689 	 * when writing to a codeword partially. 532 is the maximum possible
2690 	 * size of a codeword for our nand controller
2691 	 */
2692 	nandc->buf_size = 532;
2693 
2694 	nandc->data_buffer = devm_kzalloc(nandc->dev, nandc->buf_size,
2695 					GFP_KERNEL);
2696 	if (!nandc->data_buffer)
2697 		return -ENOMEM;
2698 
2699 	nandc->regs = devm_kzalloc(nandc->dev, sizeof(*nandc->regs),
2700 					GFP_KERNEL);
2701 	if (!nandc->regs)
2702 		return -ENOMEM;
2703 
2704 	nandc->reg_read_buf = devm_kcalloc(nandc->dev,
2705 				MAX_REG_RD, sizeof(*nandc->reg_read_buf),
2706 				GFP_KERNEL);
2707 	if (!nandc->reg_read_buf)
2708 		return -ENOMEM;
2709 
2710 	if (nandc->props->is_bam) {
2711 		nandc->reg_read_dma =
2712 			dma_map_single(nandc->dev, nandc->reg_read_buf,
2713 				       MAX_REG_RD *
2714 				       sizeof(*nandc->reg_read_buf),
2715 				       DMA_FROM_DEVICE);
2716 		if (dma_mapping_error(nandc->dev, nandc->reg_read_dma)) {
2717 			dev_err(nandc->dev, "failed to DMA MAP reg buffer\n");
2718 			return -EIO;
2719 		}
2720 
2721 		nandc->tx_chan = dma_request_chan(nandc->dev, "tx");
2722 		if (IS_ERR(nandc->tx_chan)) {
2723 			ret = PTR_ERR(nandc->tx_chan);
2724 			nandc->tx_chan = NULL;
2725 			dev_err_probe(nandc->dev, ret,
2726 				      "tx DMA channel request failed\n");
2727 			goto unalloc;
2728 		}
2729 
2730 		nandc->rx_chan = dma_request_chan(nandc->dev, "rx");
2731 		if (IS_ERR(nandc->rx_chan)) {
2732 			ret = PTR_ERR(nandc->rx_chan);
2733 			nandc->rx_chan = NULL;
2734 			dev_err_probe(nandc->dev, ret,
2735 				      "rx DMA channel request failed\n");
2736 			goto unalloc;
2737 		}
2738 
2739 		nandc->cmd_chan = dma_request_chan(nandc->dev, "cmd");
2740 		if (IS_ERR(nandc->cmd_chan)) {
2741 			ret = PTR_ERR(nandc->cmd_chan);
2742 			nandc->cmd_chan = NULL;
2743 			dev_err_probe(nandc->dev, ret,
2744 				      "cmd DMA channel request failed\n");
2745 			goto unalloc;
2746 		}
2747 
2748 		/*
2749 		 * Initially allocate BAM transaction to read ONFI param page.
2750 		 * After detecting all the devices, this BAM transaction will
2751 		 * be freed and the next BAM tranasction will be allocated with
2752 		 * maximum codeword size
2753 		 */
2754 		nandc->max_cwperpage = 1;
2755 		nandc->bam_txn = alloc_bam_transaction(nandc);
2756 		if (!nandc->bam_txn) {
2757 			dev_err(nandc->dev,
2758 				"failed to allocate bam transaction\n");
2759 			ret = -ENOMEM;
2760 			goto unalloc;
2761 		}
2762 	} else {
2763 		nandc->chan = dma_request_chan(nandc->dev, "rxtx");
2764 		if (IS_ERR(nandc->chan)) {
2765 			ret = PTR_ERR(nandc->chan);
2766 			nandc->chan = NULL;
2767 			dev_err_probe(nandc->dev, ret,
2768 				      "rxtx DMA channel request failed\n");
2769 			return ret;
2770 		}
2771 	}
2772 
2773 	INIT_LIST_HEAD(&nandc->desc_list);
2774 	INIT_LIST_HEAD(&nandc->host_list);
2775 
2776 	nand_controller_init(&nandc->controller);
2777 	nandc->controller.ops = &qcom_nandc_ops;
2778 
2779 	return 0;
2780 unalloc:
2781 	qcom_nandc_unalloc(nandc);
2782 	return ret;
2783 }
2784 
2785 /* one time setup of a few nand controller registers */
2786 static int qcom_nandc_setup(struct qcom_nand_controller *nandc)
2787 {
2788 	u32 nand_ctrl;
2789 
2790 	/* kill onenand */
2791 	if (!nandc->props->is_qpic)
2792 		nandc_write(nandc, SFLASHC_BURST_CFG, 0);
2793 
2794 	if (!nandc->props->qpic_v2)
2795 		nandc_write(nandc, dev_cmd_reg_addr(nandc, NAND_DEV_CMD_VLD),
2796 			    NAND_DEV_CMD_VLD_VAL);
2797 
2798 	/* enable ADM or BAM DMA */
2799 	if (nandc->props->is_bam) {
2800 		nand_ctrl = nandc_read(nandc, NAND_CTRL);
2801 
2802 		/*
2803 		 *NAND_CTRL is an operational registers, and CPU
2804 		 * access to operational registers are read only
2805 		 * in BAM mode. So update the NAND_CTRL register
2806 		 * only if it is not in BAM mode. In most cases BAM
2807 		 * mode will be enabled in bootloader
2808 		 */
2809 		if (!(nand_ctrl & BAM_MODE_EN))
2810 			nandc_write(nandc, NAND_CTRL, nand_ctrl | BAM_MODE_EN);
2811 	} else {
2812 		nandc_write(nandc, NAND_FLASH_CHIP_SELECT, DM_EN);
2813 	}
2814 
2815 	/* save the original values of these registers */
2816 	if (!nandc->props->qpic_v2) {
2817 		nandc->cmd1 = nandc_read(nandc, dev_cmd_reg_addr(nandc, NAND_DEV_CMD1));
2818 		nandc->vld = NAND_DEV_CMD_VLD_VAL;
2819 	}
2820 
2821 	return 0;
2822 }
2823 
2824 static int qcom_nand_host_init_and_register(struct qcom_nand_controller *nandc,
2825 					    struct qcom_nand_host *host,
2826 					    struct device_node *dn)
2827 {
2828 	struct nand_chip *chip = &host->chip;
2829 	struct mtd_info *mtd = nand_to_mtd(chip);
2830 	struct device *dev = nandc->dev;
2831 	int ret;
2832 
2833 	ret = of_property_read_u32(dn, "reg", &host->cs);
2834 	if (ret) {
2835 		dev_err(dev, "can't get chip-select\n");
2836 		return -ENXIO;
2837 	}
2838 
2839 	nand_set_flash_node(chip, dn);
2840 	mtd->name = devm_kasprintf(dev, GFP_KERNEL, "qcom_nand.%d", host->cs);
2841 	if (!mtd->name)
2842 		return -ENOMEM;
2843 
2844 	mtd->owner = THIS_MODULE;
2845 	mtd->dev.parent = dev;
2846 
2847 	chip->legacy.cmdfunc	= qcom_nandc_command;
2848 	chip->legacy.select_chip	= qcom_nandc_select_chip;
2849 	chip->legacy.read_byte	= qcom_nandc_read_byte;
2850 	chip->legacy.read_buf	= qcom_nandc_read_buf;
2851 	chip->legacy.write_buf	= qcom_nandc_write_buf;
2852 	chip->legacy.set_features	= nand_get_set_features_notsupp;
2853 	chip->legacy.get_features	= nand_get_set_features_notsupp;
2854 
2855 	/*
2856 	 * the bad block marker is readable only when we read the last codeword
2857 	 * of a page with ECC disabled. currently, the nand_base and nand_bbt
2858 	 * helpers don't allow us to read BB from a nand chip with ECC
2859 	 * disabled (MTD_OPS_PLACE_OOB is set by default). use the block_bad
2860 	 * and block_markbad helpers until we permanently switch to using
2861 	 * MTD_OPS_RAW for all drivers (with the help of badblockbits)
2862 	 */
2863 	chip->legacy.block_bad		= qcom_nandc_block_bad;
2864 	chip->legacy.block_markbad	= qcom_nandc_block_markbad;
2865 
2866 	chip->controller = &nandc->controller;
2867 	chip->options |= NAND_NO_SUBPAGE_WRITE | NAND_USES_DMA |
2868 			 NAND_SKIP_BBTSCAN;
2869 
2870 	/* set up initial status value */
2871 	host->status = NAND_STATUS_READY | NAND_STATUS_WP;
2872 
2873 	ret = nand_scan(chip, 1);
2874 	if (ret)
2875 		return ret;
2876 
2877 	if (nandc->props->is_bam) {
2878 		free_bam_transaction(nandc);
2879 		nandc->bam_txn = alloc_bam_transaction(nandc);
2880 		if (!nandc->bam_txn) {
2881 			dev_err(nandc->dev,
2882 				"failed to allocate bam transaction\n");
2883 			return -ENOMEM;
2884 		}
2885 	}
2886 
2887 	ret = mtd_device_register(mtd, NULL, 0);
2888 	if (ret)
2889 		nand_cleanup(chip);
2890 
2891 	return ret;
2892 }
2893 
2894 static int qcom_probe_nand_devices(struct qcom_nand_controller *nandc)
2895 {
2896 	struct device *dev = nandc->dev;
2897 	struct device_node *dn = dev->of_node, *child;
2898 	struct qcom_nand_host *host;
2899 	int ret;
2900 
2901 	for_each_available_child_of_node(dn, child) {
2902 		host = devm_kzalloc(dev, sizeof(*host), GFP_KERNEL);
2903 		if (!host) {
2904 			of_node_put(child);
2905 			return -ENOMEM;
2906 		}
2907 
2908 		ret = qcom_nand_host_init_and_register(nandc, host, child);
2909 		if (ret) {
2910 			devm_kfree(dev, host);
2911 			continue;
2912 		}
2913 
2914 		list_add_tail(&host->node, &nandc->host_list);
2915 	}
2916 
2917 	if (list_empty(&nandc->host_list))
2918 		return -ENODEV;
2919 
2920 	return 0;
2921 }
2922 
2923 /* parse custom DT properties here */
2924 static int qcom_nandc_parse_dt(struct platform_device *pdev)
2925 {
2926 	struct qcom_nand_controller *nandc = platform_get_drvdata(pdev);
2927 	struct device_node *np = nandc->dev->of_node;
2928 	int ret;
2929 
2930 	if (!nandc->props->is_bam) {
2931 		ret = of_property_read_u32(np, "qcom,cmd-crci",
2932 					   &nandc->cmd_crci);
2933 		if (ret) {
2934 			dev_err(nandc->dev, "command CRCI unspecified\n");
2935 			return ret;
2936 		}
2937 
2938 		ret = of_property_read_u32(np, "qcom,data-crci",
2939 					   &nandc->data_crci);
2940 		if (ret) {
2941 			dev_err(nandc->dev, "data CRCI unspecified\n");
2942 			return ret;
2943 		}
2944 	}
2945 
2946 	return 0;
2947 }
2948 
2949 static int qcom_nandc_probe(struct platform_device *pdev)
2950 {
2951 	struct qcom_nand_controller *nandc;
2952 	const void *dev_data;
2953 	struct device *dev = &pdev->dev;
2954 	struct resource *res;
2955 	int ret;
2956 
2957 	nandc = devm_kzalloc(&pdev->dev, sizeof(*nandc), GFP_KERNEL);
2958 	if (!nandc)
2959 		return -ENOMEM;
2960 
2961 	platform_set_drvdata(pdev, nandc);
2962 	nandc->dev = dev;
2963 
2964 	dev_data = of_device_get_match_data(dev);
2965 	if (!dev_data) {
2966 		dev_err(&pdev->dev, "failed to get device data\n");
2967 		return -ENODEV;
2968 	}
2969 
2970 	nandc->props = dev_data;
2971 
2972 	nandc->core_clk = devm_clk_get(dev, "core");
2973 	if (IS_ERR(nandc->core_clk))
2974 		return PTR_ERR(nandc->core_clk);
2975 
2976 	nandc->aon_clk = devm_clk_get(dev, "aon");
2977 	if (IS_ERR(nandc->aon_clk))
2978 		return PTR_ERR(nandc->aon_clk);
2979 
2980 	ret = qcom_nandc_parse_dt(pdev);
2981 	if (ret)
2982 		return ret;
2983 
2984 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
2985 	nandc->base = devm_ioremap_resource(dev, res);
2986 	if (IS_ERR(nandc->base))
2987 		return PTR_ERR(nandc->base);
2988 
2989 	nandc->base_phys = res->start;
2990 	nandc->base_dma = dma_map_resource(dev, res->start,
2991 					   resource_size(res),
2992 					   DMA_BIDIRECTIONAL, 0);
2993 	if (!nandc->base_dma)
2994 		return -ENXIO;
2995 
2996 	ret = qcom_nandc_alloc(nandc);
2997 	if (ret)
2998 		goto err_nandc_alloc;
2999 
3000 	ret = clk_prepare_enable(nandc->core_clk);
3001 	if (ret)
3002 		goto err_core_clk;
3003 
3004 	ret = clk_prepare_enable(nandc->aon_clk);
3005 	if (ret)
3006 		goto err_aon_clk;
3007 
3008 	ret = qcom_nandc_setup(nandc);
3009 	if (ret)
3010 		goto err_setup;
3011 
3012 	ret = qcom_probe_nand_devices(nandc);
3013 	if (ret)
3014 		goto err_setup;
3015 
3016 	return 0;
3017 
3018 err_setup:
3019 	clk_disable_unprepare(nandc->aon_clk);
3020 err_aon_clk:
3021 	clk_disable_unprepare(nandc->core_clk);
3022 err_core_clk:
3023 	qcom_nandc_unalloc(nandc);
3024 err_nandc_alloc:
3025 	dma_unmap_resource(dev, res->start, resource_size(res),
3026 			   DMA_BIDIRECTIONAL, 0);
3027 
3028 	return ret;
3029 }
3030 
3031 static int qcom_nandc_remove(struct platform_device *pdev)
3032 {
3033 	struct qcom_nand_controller *nandc = platform_get_drvdata(pdev);
3034 	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
3035 	struct qcom_nand_host *host;
3036 	struct nand_chip *chip;
3037 	int ret;
3038 
3039 	list_for_each_entry(host, &nandc->host_list, node) {
3040 		chip = &host->chip;
3041 		ret = mtd_device_unregister(nand_to_mtd(chip));
3042 		WARN_ON(ret);
3043 		nand_cleanup(chip);
3044 	}
3045 
3046 	qcom_nandc_unalloc(nandc);
3047 
3048 	clk_disable_unprepare(nandc->aon_clk);
3049 	clk_disable_unprepare(nandc->core_clk);
3050 
3051 	dma_unmap_resource(&pdev->dev, nandc->base_dma, resource_size(res),
3052 			   DMA_BIDIRECTIONAL, 0);
3053 
3054 	return 0;
3055 }
3056 
3057 static const struct qcom_nandc_props ipq806x_nandc_props = {
3058 	.ecc_modes = (ECC_RS_4BIT | ECC_BCH_8BIT),
3059 	.is_bam = false,
3060 	.dev_cmd_reg_start = 0x0,
3061 };
3062 
3063 static const struct qcom_nandc_props ipq4019_nandc_props = {
3064 	.ecc_modes = (ECC_BCH_4BIT | ECC_BCH_8BIT),
3065 	.is_bam = true,
3066 	.is_qpic = true,
3067 	.dev_cmd_reg_start = 0x0,
3068 };
3069 
3070 static const struct qcom_nandc_props ipq8074_nandc_props = {
3071 	.ecc_modes = (ECC_BCH_4BIT | ECC_BCH_8BIT),
3072 	.is_bam = true,
3073 	.is_qpic = true,
3074 	.dev_cmd_reg_start = 0x7000,
3075 };
3076 
3077 static const struct qcom_nandc_props sdx55_nandc_props = {
3078 	.ecc_modes = (ECC_BCH_4BIT | ECC_BCH_8BIT),
3079 	.is_bam = true,
3080 	.is_qpic = true,
3081 	.qpic_v2 = true,
3082 	.dev_cmd_reg_start = 0x7000,
3083 };
3084 
3085 /*
3086  * data will hold a struct pointer containing more differences once we support
3087  * more controller variants
3088  */
3089 static const struct of_device_id qcom_nandc_of_match[] = {
3090 	{
3091 		.compatible = "qcom,ipq806x-nand",
3092 		.data = &ipq806x_nandc_props,
3093 	},
3094 	{
3095 		.compatible = "qcom,ipq4019-nand",
3096 		.data = &ipq4019_nandc_props,
3097 	},
3098 	{
3099 		.compatible = "qcom,ipq6018-nand",
3100 		.data = &ipq8074_nandc_props,
3101 	},
3102 	{
3103 		.compatible = "qcom,ipq8074-nand",
3104 		.data = &ipq8074_nandc_props,
3105 	},
3106 	{
3107 		.compatible = "qcom,sdx55-nand",
3108 		.data = &sdx55_nandc_props,
3109 	},
3110 	{}
3111 };
3112 MODULE_DEVICE_TABLE(of, qcom_nandc_of_match);
3113 
3114 static struct platform_driver qcom_nandc_driver = {
3115 	.driver = {
3116 		.name = "qcom-nandc",
3117 		.of_match_table = qcom_nandc_of_match,
3118 	},
3119 	.probe   = qcom_nandc_probe,
3120 	.remove  = qcom_nandc_remove,
3121 };
3122 module_platform_driver(qcom_nandc_driver);
3123 
3124 MODULE_AUTHOR("Archit Taneja <architt@codeaurora.org>");
3125 MODULE_DESCRIPTION("Qualcomm NAND Controller driver");
3126 MODULE_LICENSE("GPL v2");
3127