xref: /openbmc/linux/drivers/mtd/nand/raw/tegra_nand.c (revision 9b93eb47)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2018 Stefan Agner <stefan@agner.ch>
4  * Copyright (C) 2014-2015 Lucas Stach <dev@lynxeye.de>
5  * Copyright (C) 2012 Avionic Design GmbH
6  */
7 
8 #include <linux/clk.h>
9 #include <linux/completion.h>
10 #include <linux/dma-mapping.h>
11 #include <linux/err.h>
12 #include <linux/gpio/consumer.h>
13 #include <linux/interrupt.h>
14 #include <linux/io.h>
15 #include <linux/module.h>
16 #include <linux/mtd/partitions.h>
17 #include <linux/mtd/rawnand.h>
18 #include <linux/of.h>
19 #include <linux/platform_device.h>
20 #include <linux/reset.h>
21 
22 #define COMMAND					0x00
23 #define   COMMAND_GO				BIT(31)
24 #define   COMMAND_CLE				BIT(30)
25 #define   COMMAND_ALE				BIT(29)
26 #define   COMMAND_PIO				BIT(28)
27 #define   COMMAND_TX				BIT(27)
28 #define   COMMAND_RX				BIT(26)
29 #define   COMMAND_SEC_CMD			BIT(25)
30 #define   COMMAND_AFT_DAT			BIT(24)
31 #define   COMMAND_TRANS_SIZE(size)		((((size) - 1) & 0xf) << 20)
32 #define   COMMAND_A_VALID			BIT(19)
33 #define   COMMAND_B_VALID			BIT(18)
34 #define   COMMAND_RD_STATUS_CHK			BIT(17)
35 #define   COMMAND_RBSY_CHK			BIT(16)
36 #define   COMMAND_CE(x)				BIT(8 + ((x) & 0x7))
37 #define   COMMAND_CLE_SIZE(size)		((((size) - 1) & 0x3) << 4)
38 #define   COMMAND_ALE_SIZE(size)		((((size) - 1) & 0xf) << 0)
39 
40 #define STATUS					0x04
41 
42 #define ISR					0x08
43 #define   ISR_CORRFAIL_ERR			BIT(24)
44 #define   ISR_UND				BIT(7)
45 #define   ISR_OVR				BIT(6)
46 #define   ISR_CMD_DONE				BIT(5)
47 #define   ISR_ECC_ERR				BIT(4)
48 
49 #define IER					0x0c
50 #define   IER_ERR_TRIG_VAL(x)			(((x) & 0xf) << 16)
51 #define   IER_UND				BIT(7)
52 #define   IER_OVR				BIT(6)
53 #define   IER_CMD_DONE				BIT(5)
54 #define   IER_ECC_ERR				BIT(4)
55 #define   IER_GIE				BIT(0)
56 
57 #define CONFIG					0x10
58 #define   CONFIG_HW_ECC				BIT(31)
59 #define   CONFIG_ECC_SEL			BIT(30)
60 #define   CONFIG_ERR_COR			BIT(29)
61 #define   CONFIG_PIPE_EN			BIT(28)
62 #define   CONFIG_TVAL_4				(0 << 24)
63 #define   CONFIG_TVAL_6				(1 << 24)
64 #define   CONFIG_TVAL_8				(2 << 24)
65 #define   CONFIG_SKIP_SPARE			BIT(23)
66 #define   CONFIG_BUS_WIDTH_16			BIT(21)
67 #define   CONFIG_COM_BSY			BIT(20)
68 #define   CONFIG_PS_256				(0 << 16)
69 #define   CONFIG_PS_512				(1 << 16)
70 #define   CONFIG_PS_1024			(2 << 16)
71 #define   CONFIG_PS_2048			(3 << 16)
72 #define   CONFIG_PS_4096			(4 << 16)
73 #define   CONFIG_SKIP_SPARE_SIZE_4		(0 << 14)
74 #define   CONFIG_SKIP_SPARE_SIZE_8		(1 << 14)
75 #define   CONFIG_SKIP_SPARE_SIZE_12		(2 << 14)
76 #define   CONFIG_SKIP_SPARE_SIZE_16		(3 << 14)
77 #define   CONFIG_TAG_BYTE_SIZE(x)			((x) & 0xff)
78 
79 #define TIMING_1				0x14
80 #define   TIMING_TRP_RESP(x)			(((x) & 0xf) << 28)
81 #define   TIMING_TWB(x)				(((x) & 0xf) << 24)
82 #define   TIMING_TCR_TAR_TRR(x)			(((x) & 0xf) << 20)
83 #define   TIMING_TWHR(x)			(((x) & 0xf) << 16)
84 #define   TIMING_TCS(x)				(((x) & 0x3) << 14)
85 #define   TIMING_TWH(x)				(((x) & 0x3) << 12)
86 #define   TIMING_TWP(x)				(((x) & 0xf) <<  8)
87 #define   TIMING_TRH(x)				(((x) & 0x3) <<  4)
88 #define   TIMING_TRP(x)				(((x) & 0xf) <<  0)
89 
90 #define RESP					0x18
91 
92 #define TIMING_2				0x1c
93 #define   TIMING_TADL(x)			((x) & 0xf)
94 
95 #define CMD_REG1				0x20
96 #define CMD_REG2				0x24
97 #define ADDR_REG1				0x28
98 #define ADDR_REG2				0x2c
99 
100 #define DMA_MST_CTRL				0x30
101 #define   DMA_MST_CTRL_GO			BIT(31)
102 #define   DMA_MST_CTRL_IN			(0 << 30)
103 #define   DMA_MST_CTRL_OUT			BIT(30)
104 #define   DMA_MST_CTRL_PERF_EN			BIT(29)
105 #define   DMA_MST_CTRL_IE_DONE			BIT(28)
106 #define   DMA_MST_CTRL_REUSE			BIT(27)
107 #define   DMA_MST_CTRL_BURST_1			(2 << 24)
108 #define   DMA_MST_CTRL_BURST_4			(3 << 24)
109 #define   DMA_MST_CTRL_BURST_8			(4 << 24)
110 #define   DMA_MST_CTRL_BURST_16			(5 << 24)
111 #define   DMA_MST_CTRL_IS_DONE			BIT(20)
112 #define   DMA_MST_CTRL_EN_A			BIT(2)
113 #define   DMA_MST_CTRL_EN_B			BIT(1)
114 
115 #define DMA_CFG_A				0x34
116 #define DMA_CFG_B				0x38
117 
118 #define FIFO_CTRL				0x3c
119 #define   FIFO_CTRL_CLR_ALL			BIT(3)
120 
121 #define DATA_PTR				0x40
122 #define TAG_PTR					0x44
123 #define ECC_PTR					0x48
124 
125 #define DEC_STATUS				0x4c
126 #define   DEC_STATUS_A_ECC_FAIL			BIT(1)
127 #define   DEC_STATUS_ERR_COUNT_MASK		0x00ff0000
128 #define   DEC_STATUS_ERR_COUNT_SHIFT		16
129 
130 #define HWSTATUS_CMD				0x50
131 #define HWSTATUS_MASK				0x54
132 #define   HWSTATUS_RDSTATUS_MASK(x)		(((x) & 0xff) << 24)
133 #define   HWSTATUS_RDSTATUS_VALUE(x)		(((x) & 0xff) << 16)
134 #define   HWSTATUS_RBSY_MASK(x)			(((x) & 0xff) << 8)
135 #define   HWSTATUS_RBSY_VALUE(x)		(((x) & 0xff) << 0)
136 
137 #define BCH_CONFIG				0xcc
138 #define   BCH_ENABLE				BIT(0)
139 #define   BCH_TVAL_4				(0 << 4)
140 #define   BCH_TVAL_8				(1 << 4)
141 #define   BCH_TVAL_14				(2 << 4)
142 #define   BCH_TVAL_16				(3 << 4)
143 
144 #define DEC_STAT_RESULT				0xd0
145 #define DEC_STAT_BUF				0xd4
146 #define   DEC_STAT_BUF_FAIL_SEC_FLAG_MASK	0xff000000
147 #define   DEC_STAT_BUF_FAIL_SEC_FLAG_SHIFT	24
148 #define   DEC_STAT_BUF_CORR_SEC_FLAG_MASK	0x00ff0000
149 #define   DEC_STAT_BUF_CORR_SEC_FLAG_SHIFT	16
150 #define   DEC_STAT_BUF_MAX_CORR_CNT_MASK	0x00001f00
151 #define   DEC_STAT_BUF_MAX_CORR_CNT_SHIFT	8
152 
153 #define OFFSET(val, off)	((val) < (off) ? 0 : (val) - (off))
154 
155 #define SKIP_SPARE_BYTES	4
156 #define BITS_PER_STEP_RS	18
157 #define BITS_PER_STEP_BCH	13
158 
159 #define INT_MASK		(IER_UND | IER_OVR | IER_CMD_DONE | IER_GIE)
160 #define HWSTATUS_CMD_DEFAULT	NAND_STATUS_READY
161 #define HWSTATUS_MASK_DEFAULT	(HWSTATUS_RDSTATUS_MASK(1) | \
162 				HWSTATUS_RDSTATUS_VALUE(0) | \
163 				HWSTATUS_RBSY_MASK(NAND_STATUS_READY) | \
164 				HWSTATUS_RBSY_VALUE(NAND_STATUS_READY))
165 
166 struct tegra_nand_controller {
167 	struct nand_controller controller;
168 	struct device *dev;
169 	void __iomem *regs;
170 	int irq;
171 	struct clk *clk;
172 	struct completion command_complete;
173 	struct completion dma_complete;
174 	bool last_read_error;
175 	int cur_cs;
176 	struct nand_chip *chip;
177 };
178 
179 struct tegra_nand_chip {
180 	struct nand_chip chip;
181 	struct gpio_desc *wp_gpio;
182 	struct mtd_oob_region ecc;
183 	u32 config;
184 	u32 config_ecc;
185 	u32 bch_config;
186 	int cs[1];
187 };
188 
189 static inline struct tegra_nand_controller *
190 			to_tegra_ctrl(struct nand_controller *hw_ctrl)
191 {
192 	return container_of(hw_ctrl, struct tegra_nand_controller, controller);
193 }
194 
195 static inline struct tegra_nand_chip *to_tegra_chip(struct nand_chip *chip)
196 {
197 	return container_of(chip, struct tegra_nand_chip, chip);
198 }
199 
200 static int tegra_nand_ooblayout_rs_ecc(struct mtd_info *mtd, int section,
201 				       struct mtd_oob_region *oobregion)
202 {
203 	struct nand_chip *chip = mtd_to_nand(mtd);
204 	int bytes_per_step = DIV_ROUND_UP(BITS_PER_STEP_RS * chip->ecc.strength,
205 					  BITS_PER_BYTE);
206 
207 	if (section > 0)
208 		return -ERANGE;
209 
210 	oobregion->offset = SKIP_SPARE_BYTES;
211 	oobregion->length = round_up(bytes_per_step * chip->ecc.steps, 4);
212 
213 	return 0;
214 }
215 
216 static int tegra_nand_ooblayout_no_free(struct mtd_info *mtd, int section,
217 					struct mtd_oob_region *oobregion)
218 {
219 	return -ERANGE;
220 }
221 
222 static const struct mtd_ooblayout_ops tegra_nand_oob_rs_ops = {
223 	.ecc = tegra_nand_ooblayout_rs_ecc,
224 	.free = tegra_nand_ooblayout_no_free,
225 };
226 
227 static int tegra_nand_ooblayout_bch_ecc(struct mtd_info *mtd, int section,
228 					struct mtd_oob_region *oobregion)
229 {
230 	struct nand_chip *chip = mtd_to_nand(mtd);
231 	int bytes_per_step = DIV_ROUND_UP(BITS_PER_STEP_BCH * chip->ecc.strength,
232 					  BITS_PER_BYTE);
233 
234 	if (section > 0)
235 		return -ERANGE;
236 
237 	oobregion->offset = SKIP_SPARE_BYTES;
238 	oobregion->length = round_up(bytes_per_step * chip->ecc.steps, 4);
239 
240 	return 0;
241 }
242 
243 static const struct mtd_ooblayout_ops tegra_nand_oob_bch_ops = {
244 	.ecc = tegra_nand_ooblayout_bch_ecc,
245 	.free = tegra_nand_ooblayout_no_free,
246 };
247 
248 static irqreturn_t tegra_nand_irq(int irq, void *data)
249 {
250 	struct tegra_nand_controller *ctrl = data;
251 	u32 isr, dma;
252 
253 	isr = readl_relaxed(ctrl->regs + ISR);
254 	dma = readl_relaxed(ctrl->regs + DMA_MST_CTRL);
255 	dev_dbg(ctrl->dev, "isr %08x\n", isr);
256 
257 	if (!isr && !(dma & DMA_MST_CTRL_IS_DONE))
258 		return IRQ_NONE;
259 
260 	/*
261 	 * The bit name is somewhat missleading: This is also set when
262 	 * HW ECC was successful. The data sheet states:
263 	 * Correctable OR Un-correctable errors occurred in the DMA transfer...
264 	 */
265 	if (isr & ISR_CORRFAIL_ERR)
266 		ctrl->last_read_error = true;
267 
268 	if (isr & ISR_CMD_DONE)
269 		complete(&ctrl->command_complete);
270 
271 	if (isr & ISR_UND)
272 		dev_err(ctrl->dev, "FIFO underrun\n");
273 
274 	if (isr & ISR_OVR)
275 		dev_err(ctrl->dev, "FIFO overrun\n");
276 
277 	/* handle DMA interrupts */
278 	if (dma & DMA_MST_CTRL_IS_DONE) {
279 		writel_relaxed(dma, ctrl->regs + DMA_MST_CTRL);
280 		complete(&ctrl->dma_complete);
281 	}
282 
283 	/* clear interrupts */
284 	writel_relaxed(isr, ctrl->regs + ISR);
285 
286 	return IRQ_HANDLED;
287 }
288 
289 static const char * const tegra_nand_reg_names[] = {
290 	"COMMAND",
291 	"STATUS",
292 	"ISR",
293 	"IER",
294 	"CONFIG",
295 	"TIMING",
296 	NULL,
297 	"TIMING2",
298 	"CMD_REG1",
299 	"CMD_REG2",
300 	"ADDR_REG1",
301 	"ADDR_REG2",
302 	"DMA_MST_CTRL",
303 	"DMA_CFG_A",
304 	"DMA_CFG_B",
305 	"FIFO_CTRL",
306 };
307 
308 static void tegra_nand_dump_reg(struct tegra_nand_controller *ctrl)
309 {
310 	u32 reg;
311 	int i;
312 
313 	dev_err(ctrl->dev, "Tegra NAND controller register dump\n");
314 	for (i = 0; i < ARRAY_SIZE(tegra_nand_reg_names); i++) {
315 		const char *reg_name = tegra_nand_reg_names[i];
316 
317 		if (!reg_name)
318 			continue;
319 
320 		reg = readl_relaxed(ctrl->regs + (i * 4));
321 		dev_err(ctrl->dev, "%s: 0x%08x\n", reg_name, reg);
322 	}
323 }
324 
325 static void tegra_nand_controller_abort(struct tegra_nand_controller *ctrl)
326 {
327 	u32 isr, dma;
328 
329 	disable_irq(ctrl->irq);
330 
331 	/* Abort current command/DMA operation */
332 	writel_relaxed(0, ctrl->regs + DMA_MST_CTRL);
333 	writel_relaxed(0, ctrl->regs + COMMAND);
334 
335 	/* clear interrupts */
336 	isr = readl_relaxed(ctrl->regs + ISR);
337 	writel_relaxed(isr, ctrl->regs + ISR);
338 	dma = readl_relaxed(ctrl->regs + DMA_MST_CTRL);
339 	writel_relaxed(dma, ctrl->regs + DMA_MST_CTRL);
340 
341 	reinit_completion(&ctrl->command_complete);
342 	reinit_completion(&ctrl->dma_complete);
343 
344 	enable_irq(ctrl->irq);
345 }
346 
347 static int tegra_nand_cmd(struct nand_chip *chip,
348 			  const struct nand_subop *subop)
349 {
350 	const struct nand_op_instr *instr;
351 	const struct nand_op_instr *instr_data_in = NULL;
352 	struct tegra_nand_controller *ctrl = to_tegra_ctrl(chip->controller);
353 	unsigned int op_id, size = 0, offset = 0;
354 	bool first_cmd = true;
355 	u32 reg, cmd = 0;
356 	int ret;
357 
358 	for (op_id = 0; op_id < subop->ninstrs; op_id++) {
359 		unsigned int naddrs, i;
360 		const u8 *addrs;
361 		u32 addr1 = 0, addr2 = 0;
362 
363 		instr = &subop->instrs[op_id];
364 
365 		switch (instr->type) {
366 		case NAND_OP_CMD_INSTR:
367 			if (first_cmd) {
368 				cmd |= COMMAND_CLE;
369 				writel_relaxed(instr->ctx.cmd.opcode,
370 					       ctrl->regs + CMD_REG1);
371 			} else {
372 				cmd |= COMMAND_SEC_CMD;
373 				writel_relaxed(instr->ctx.cmd.opcode,
374 					       ctrl->regs + CMD_REG2);
375 			}
376 			first_cmd = false;
377 			break;
378 
379 		case NAND_OP_ADDR_INSTR:
380 			offset = nand_subop_get_addr_start_off(subop, op_id);
381 			naddrs = nand_subop_get_num_addr_cyc(subop, op_id);
382 			addrs = &instr->ctx.addr.addrs[offset];
383 
384 			cmd |= COMMAND_ALE | COMMAND_ALE_SIZE(naddrs);
385 			for (i = 0; i < min_t(unsigned int, 4, naddrs); i++)
386 				addr1 |= *addrs++ << (BITS_PER_BYTE * i);
387 			naddrs -= i;
388 			for (i = 0; i < min_t(unsigned int, 4, naddrs); i++)
389 				addr2 |= *addrs++ << (BITS_PER_BYTE * i);
390 
391 			writel_relaxed(addr1, ctrl->regs + ADDR_REG1);
392 			writel_relaxed(addr2, ctrl->regs + ADDR_REG2);
393 			break;
394 
395 		case NAND_OP_DATA_IN_INSTR:
396 			size = nand_subop_get_data_len(subop, op_id);
397 			offset = nand_subop_get_data_start_off(subop, op_id);
398 
399 			cmd |= COMMAND_TRANS_SIZE(size) | COMMAND_PIO |
400 				COMMAND_RX | COMMAND_A_VALID;
401 
402 			instr_data_in = instr;
403 			break;
404 
405 		case NAND_OP_DATA_OUT_INSTR:
406 			size = nand_subop_get_data_len(subop, op_id);
407 			offset = nand_subop_get_data_start_off(subop, op_id);
408 
409 			cmd |= COMMAND_TRANS_SIZE(size) | COMMAND_PIO |
410 				COMMAND_TX | COMMAND_A_VALID;
411 			memcpy(&reg, instr->ctx.data.buf.out + offset, size);
412 
413 			writel_relaxed(reg, ctrl->regs + RESP);
414 			break;
415 
416 		case NAND_OP_WAITRDY_INSTR:
417 			cmd |= COMMAND_RBSY_CHK;
418 			break;
419 		}
420 	}
421 
422 	cmd |= COMMAND_GO | COMMAND_CE(ctrl->cur_cs);
423 	writel_relaxed(cmd, ctrl->regs + COMMAND);
424 	ret = wait_for_completion_timeout(&ctrl->command_complete,
425 					  msecs_to_jiffies(500));
426 	if (!ret) {
427 		dev_err(ctrl->dev, "COMMAND timeout\n");
428 		tegra_nand_dump_reg(ctrl);
429 		tegra_nand_controller_abort(ctrl);
430 		return -ETIMEDOUT;
431 	}
432 
433 	if (instr_data_in) {
434 		reg = readl_relaxed(ctrl->regs + RESP);
435 		memcpy(instr_data_in->ctx.data.buf.in + offset, &reg, size);
436 	}
437 
438 	return 0;
439 }
440 
441 static const struct nand_op_parser tegra_nand_op_parser = NAND_OP_PARSER(
442 	NAND_OP_PARSER_PATTERN(tegra_nand_cmd,
443 		NAND_OP_PARSER_PAT_CMD_ELEM(true),
444 		NAND_OP_PARSER_PAT_ADDR_ELEM(true, 8),
445 		NAND_OP_PARSER_PAT_CMD_ELEM(true),
446 		NAND_OP_PARSER_PAT_WAITRDY_ELEM(true)),
447 	NAND_OP_PARSER_PATTERN(tegra_nand_cmd,
448 		NAND_OP_PARSER_PAT_DATA_OUT_ELEM(false, 4)),
449 	NAND_OP_PARSER_PATTERN(tegra_nand_cmd,
450 		NAND_OP_PARSER_PAT_CMD_ELEM(true),
451 		NAND_OP_PARSER_PAT_ADDR_ELEM(true, 8),
452 		NAND_OP_PARSER_PAT_CMD_ELEM(true),
453 		NAND_OP_PARSER_PAT_WAITRDY_ELEM(true),
454 		NAND_OP_PARSER_PAT_DATA_IN_ELEM(true, 4)),
455 	);
456 
457 static void tegra_nand_select_target(struct nand_chip *chip,
458 				     unsigned int die_nr)
459 {
460 	struct tegra_nand_chip *nand = to_tegra_chip(chip);
461 	struct tegra_nand_controller *ctrl = to_tegra_ctrl(chip->controller);
462 
463 	ctrl->cur_cs = nand->cs[die_nr];
464 }
465 
466 static int tegra_nand_exec_op(struct nand_chip *chip,
467 			      const struct nand_operation *op,
468 			      bool check_only)
469 {
470 	tegra_nand_select_target(chip, op->cs);
471 	return nand_op_parser_exec_op(chip, &tegra_nand_op_parser, op,
472 				      check_only);
473 }
474 
475 static void tegra_nand_hw_ecc(struct tegra_nand_controller *ctrl,
476 			      struct nand_chip *chip, bool enable)
477 {
478 	struct tegra_nand_chip *nand = to_tegra_chip(chip);
479 
480 	if (chip->ecc.algo == NAND_ECC_BCH && enable)
481 		writel_relaxed(nand->bch_config, ctrl->regs + BCH_CONFIG);
482 	else
483 		writel_relaxed(0, ctrl->regs + BCH_CONFIG);
484 
485 	if (enable)
486 		writel_relaxed(nand->config_ecc, ctrl->regs + CONFIG);
487 	else
488 		writel_relaxed(nand->config, ctrl->regs + CONFIG);
489 }
490 
491 static int tegra_nand_page_xfer(struct mtd_info *mtd, struct nand_chip *chip,
492 				void *buf, void *oob_buf, int oob_len, int page,
493 				bool read)
494 {
495 	struct tegra_nand_controller *ctrl = to_tegra_ctrl(chip->controller);
496 	enum dma_data_direction dir = read ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
497 	dma_addr_t dma_addr = 0, dma_addr_oob = 0;
498 	u32 addr1, cmd, dma_ctrl;
499 	int ret;
500 
501 	tegra_nand_select_target(chip, chip->cur_cs);
502 
503 	if (read) {
504 		writel_relaxed(NAND_CMD_READ0, ctrl->regs + CMD_REG1);
505 		writel_relaxed(NAND_CMD_READSTART, ctrl->regs + CMD_REG2);
506 	} else {
507 		writel_relaxed(NAND_CMD_SEQIN, ctrl->regs + CMD_REG1);
508 		writel_relaxed(NAND_CMD_PAGEPROG, ctrl->regs + CMD_REG2);
509 	}
510 	cmd = COMMAND_CLE | COMMAND_SEC_CMD;
511 
512 	/* Lower 16-bits are column, by default 0 */
513 	addr1 = page << 16;
514 
515 	if (!buf)
516 		addr1 |= mtd->writesize;
517 	writel_relaxed(addr1, ctrl->regs + ADDR_REG1);
518 
519 	if (chip->options & NAND_ROW_ADDR_3) {
520 		writel_relaxed(page >> 16, ctrl->regs + ADDR_REG2);
521 		cmd |= COMMAND_ALE | COMMAND_ALE_SIZE(5);
522 	} else {
523 		cmd |= COMMAND_ALE | COMMAND_ALE_SIZE(4);
524 	}
525 
526 	if (buf) {
527 		dma_addr = dma_map_single(ctrl->dev, buf, mtd->writesize, dir);
528 		ret = dma_mapping_error(ctrl->dev, dma_addr);
529 		if (ret) {
530 			dev_err(ctrl->dev, "dma mapping error\n");
531 			return -EINVAL;
532 		}
533 
534 		writel_relaxed(mtd->writesize - 1, ctrl->regs + DMA_CFG_A);
535 		writel_relaxed(dma_addr, ctrl->regs + DATA_PTR);
536 	}
537 
538 	if (oob_buf) {
539 		dma_addr_oob = dma_map_single(ctrl->dev, oob_buf, mtd->oobsize,
540 					      dir);
541 		ret = dma_mapping_error(ctrl->dev, dma_addr_oob);
542 		if (ret) {
543 			dev_err(ctrl->dev, "dma mapping error\n");
544 			ret = -EINVAL;
545 			goto err_unmap_dma_page;
546 		}
547 
548 		writel_relaxed(oob_len - 1, ctrl->regs + DMA_CFG_B);
549 		writel_relaxed(dma_addr_oob, ctrl->regs + TAG_PTR);
550 	}
551 
552 	dma_ctrl = DMA_MST_CTRL_GO | DMA_MST_CTRL_PERF_EN |
553 		   DMA_MST_CTRL_IE_DONE | DMA_MST_CTRL_IS_DONE |
554 		   DMA_MST_CTRL_BURST_16;
555 
556 	if (buf)
557 		dma_ctrl |= DMA_MST_CTRL_EN_A;
558 	if (oob_buf)
559 		dma_ctrl |= DMA_MST_CTRL_EN_B;
560 
561 	if (read)
562 		dma_ctrl |= DMA_MST_CTRL_IN | DMA_MST_CTRL_REUSE;
563 	else
564 		dma_ctrl |= DMA_MST_CTRL_OUT;
565 
566 	writel_relaxed(dma_ctrl, ctrl->regs + DMA_MST_CTRL);
567 
568 	cmd |= COMMAND_GO | COMMAND_RBSY_CHK | COMMAND_TRANS_SIZE(9) |
569 	       COMMAND_CE(ctrl->cur_cs);
570 
571 	if (buf)
572 		cmd |= COMMAND_A_VALID;
573 	if (oob_buf)
574 		cmd |= COMMAND_B_VALID;
575 
576 	if (read)
577 		cmd |= COMMAND_RX;
578 	else
579 		cmd |= COMMAND_TX | COMMAND_AFT_DAT;
580 
581 	writel_relaxed(cmd, ctrl->regs + COMMAND);
582 
583 	ret = wait_for_completion_timeout(&ctrl->command_complete,
584 					  msecs_to_jiffies(500));
585 	if (!ret) {
586 		dev_err(ctrl->dev, "COMMAND timeout\n");
587 		tegra_nand_dump_reg(ctrl);
588 		tegra_nand_controller_abort(ctrl);
589 		ret = -ETIMEDOUT;
590 		goto err_unmap_dma;
591 	}
592 
593 	ret = wait_for_completion_timeout(&ctrl->dma_complete,
594 					  msecs_to_jiffies(500));
595 	if (!ret) {
596 		dev_err(ctrl->dev, "DMA timeout\n");
597 		tegra_nand_dump_reg(ctrl);
598 		tegra_nand_controller_abort(ctrl);
599 		ret = -ETIMEDOUT;
600 		goto err_unmap_dma;
601 	}
602 	ret = 0;
603 
604 err_unmap_dma:
605 	if (oob_buf)
606 		dma_unmap_single(ctrl->dev, dma_addr_oob, mtd->oobsize, dir);
607 err_unmap_dma_page:
608 	if (buf)
609 		dma_unmap_single(ctrl->dev, dma_addr, mtd->writesize, dir);
610 
611 	return ret;
612 }
613 
614 static int tegra_nand_read_page_raw(struct nand_chip *chip, u8 *buf,
615 				    int oob_required, int page)
616 {
617 	struct mtd_info *mtd = nand_to_mtd(chip);
618 	void *oob_buf = oob_required ? chip->oob_poi : NULL;
619 
620 	return tegra_nand_page_xfer(mtd, chip, buf, oob_buf,
621 				    mtd->oobsize, page, true);
622 }
623 
624 static int tegra_nand_write_page_raw(struct nand_chip *chip, const u8 *buf,
625 				     int oob_required, int page)
626 {
627 	struct mtd_info *mtd = nand_to_mtd(chip);
628 	void *oob_buf = oob_required ? chip->oob_poi : NULL;
629 
630 	return tegra_nand_page_xfer(mtd, chip, (void *)buf, oob_buf,
631 				     mtd->oobsize, page, false);
632 }
633 
634 static int tegra_nand_read_oob(struct nand_chip *chip, int page)
635 {
636 	struct mtd_info *mtd = nand_to_mtd(chip);
637 
638 	return tegra_nand_page_xfer(mtd, chip, NULL, chip->oob_poi,
639 				    mtd->oobsize, page, true);
640 }
641 
642 static int tegra_nand_write_oob(struct nand_chip *chip, int page)
643 {
644 	struct mtd_info *mtd = nand_to_mtd(chip);
645 
646 	return tegra_nand_page_xfer(mtd, chip, NULL, chip->oob_poi,
647 				    mtd->oobsize, page, false);
648 }
649 
650 static int tegra_nand_read_page_hwecc(struct nand_chip *chip, u8 *buf,
651 				      int oob_required, int page)
652 {
653 	struct mtd_info *mtd = nand_to_mtd(chip);
654 	struct tegra_nand_controller *ctrl = to_tegra_ctrl(chip->controller);
655 	struct tegra_nand_chip *nand = to_tegra_chip(chip);
656 	void *oob_buf = oob_required ? chip->oob_poi : NULL;
657 	u32 dec_stat, max_corr_cnt;
658 	unsigned long fail_sec_flag;
659 	int ret;
660 
661 	tegra_nand_hw_ecc(ctrl, chip, true);
662 	ret = tegra_nand_page_xfer(mtd, chip, buf, oob_buf, 0, page, true);
663 	tegra_nand_hw_ecc(ctrl, chip, false);
664 	if (ret)
665 		return ret;
666 
667 	/* No correctable or un-correctable errors, page must have 0 bitflips */
668 	if (!ctrl->last_read_error)
669 		return 0;
670 
671 	/*
672 	 * Correctable or un-correctable errors occurred. Use DEC_STAT_BUF
673 	 * which contains information for all ECC selections.
674 	 *
675 	 * Note that since we do not use Command Queues DEC_RESULT does not
676 	 * state the number of pages we can read from the DEC_STAT_BUF. But
677 	 * since CORRFAIL_ERR did occur during page read we do have a valid
678 	 * result in DEC_STAT_BUF.
679 	 */
680 	ctrl->last_read_error = false;
681 	dec_stat = readl_relaxed(ctrl->regs + DEC_STAT_BUF);
682 
683 	fail_sec_flag = (dec_stat & DEC_STAT_BUF_FAIL_SEC_FLAG_MASK) >>
684 			DEC_STAT_BUF_FAIL_SEC_FLAG_SHIFT;
685 
686 	max_corr_cnt = (dec_stat & DEC_STAT_BUF_MAX_CORR_CNT_MASK) >>
687 		       DEC_STAT_BUF_MAX_CORR_CNT_SHIFT;
688 
689 	if (fail_sec_flag) {
690 		int bit, max_bitflips = 0;
691 
692 		/*
693 		 * Since we do not support subpage writes, a complete page
694 		 * is either written or not. We can take a shortcut here by
695 		 * checking wheather any of the sector has been successful
696 		 * read. If at least one sectors has been read successfully,
697 		 * the page must have been a written previously. It cannot
698 		 * be an erased page.
699 		 *
700 		 * E.g. controller might return fail_sec_flag with 0x4, which
701 		 * would mean only the third sector failed to correct. The
702 		 * page must have been written and the third sector is really
703 		 * not correctable anymore.
704 		 */
705 		if (fail_sec_flag ^ GENMASK(chip->ecc.steps - 1, 0)) {
706 			mtd->ecc_stats.failed += hweight8(fail_sec_flag);
707 			return max_corr_cnt;
708 		}
709 
710 		/*
711 		 * All sectors failed to correct, but the ECC isn't smart
712 		 * enough to figure out if a page is really just erased.
713 		 * Read OOB data and check whether data/OOB is completely
714 		 * erased or if error correction just failed for all sub-
715 		 * pages.
716 		 */
717 		ret = tegra_nand_read_oob(chip, page);
718 		if (ret < 0)
719 			return ret;
720 
721 		for_each_set_bit(bit, &fail_sec_flag, chip->ecc.steps) {
722 			u8 *data = buf + (chip->ecc.size * bit);
723 			u8 *oob = chip->oob_poi + nand->ecc.offset +
724 				  (chip->ecc.bytes * bit);
725 
726 			ret = nand_check_erased_ecc_chunk(data, chip->ecc.size,
727 							  oob, chip->ecc.bytes,
728 							  NULL, 0,
729 							  chip->ecc.strength);
730 			if (ret < 0) {
731 				mtd->ecc_stats.failed++;
732 			} else {
733 				mtd->ecc_stats.corrected += ret;
734 				max_bitflips = max(ret, max_bitflips);
735 			}
736 		}
737 
738 		return max_t(unsigned int, max_corr_cnt, max_bitflips);
739 	} else {
740 		int corr_sec_flag;
741 
742 		corr_sec_flag = (dec_stat & DEC_STAT_BUF_CORR_SEC_FLAG_MASK) >>
743 				DEC_STAT_BUF_CORR_SEC_FLAG_SHIFT;
744 
745 		/*
746 		 * The value returned in the register is the maximum of
747 		 * bitflips encountered in any of the ECC regions. As there is
748 		 * no way to get the number of bitflips in a specific regions
749 		 * we are not able to deliver correct stats but instead
750 		 * overestimate the number of corrected bitflips by assuming
751 		 * that all regions where errors have been corrected
752 		 * encountered the maximum number of bitflips.
753 		 */
754 		mtd->ecc_stats.corrected += max_corr_cnt * hweight8(corr_sec_flag);
755 
756 		return max_corr_cnt;
757 	}
758 }
759 
760 static int tegra_nand_write_page_hwecc(struct nand_chip *chip, const u8 *buf,
761 				       int oob_required, int page)
762 {
763 	struct mtd_info *mtd = nand_to_mtd(chip);
764 	struct tegra_nand_controller *ctrl = to_tegra_ctrl(chip->controller);
765 	void *oob_buf = oob_required ? chip->oob_poi : NULL;
766 	int ret;
767 
768 	tegra_nand_hw_ecc(ctrl, chip, true);
769 	ret = tegra_nand_page_xfer(mtd, chip, (void *)buf, oob_buf,
770 				   0, page, false);
771 	tegra_nand_hw_ecc(ctrl, chip, false);
772 
773 	return ret;
774 }
775 
776 static void tegra_nand_setup_timing(struct tegra_nand_controller *ctrl,
777 				    const struct nand_sdr_timings *timings)
778 {
779 	/*
780 	 * The period (and all other timings in this function) is in ps,
781 	 * so need to take care here to avoid integer overflows.
782 	 */
783 	unsigned int rate = clk_get_rate(ctrl->clk) / 1000000;
784 	unsigned int period = DIV_ROUND_UP(1000000, rate);
785 	u32 val, reg = 0;
786 
787 	val = DIV_ROUND_UP(max3(timings->tAR_min, timings->tRR_min,
788 				timings->tRC_min), period);
789 	reg |= TIMING_TCR_TAR_TRR(OFFSET(val, 3));
790 
791 	val = DIV_ROUND_UP(max(max(timings->tCS_min, timings->tCH_min),
792 			       max(timings->tALS_min, timings->tALH_min)),
793 			   period);
794 	reg |= TIMING_TCS(OFFSET(val, 2));
795 
796 	val = DIV_ROUND_UP(max(timings->tRP_min, timings->tREA_max) + 6000,
797 			   period);
798 	reg |= TIMING_TRP(OFFSET(val, 1)) | TIMING_TRP_RESP(OFFSET(val, 1));
799 
800 	reg |= TIMING_TWB(OFFSET(DIV_ROUND_UP(timings->tWB_max, period), 1));
801 	reg |= TIMING_TWHR(OFFSET(DIV_ROUND_UP(timings->tWHR_min, period), 1));
802 	reg |= TIMING_TWH(OFFSET(DIV_ROUND_UP(timings->tWH_min, period), 1));
803 	reg |= TIMING_TWP(OFFSET(DIV_ROUND_UP(timings->tWP_min, period), 1));
804 	reg |= TIMING_TRH(OFFSET(DIV_ROUND_UP(timings->tREH_min, period), 1));
805 
806 	writel_relaxed(reg, ctrl->regs + TIMING_1);
807 
808 	val = DIV_ROUND_UP(timings->tADL_min, period);
809 	reg = TIMING_TADL(OFFSET(val, 3));
810 
811 	writel_relaxed(reg, ctrl->regs + TIMING_2);
812 }
813 
814 static int tegra_nand_setup_data_interface(struct nand_chip *chip, int csline,
815 					const struct nand_data_interface *conf)
816 {
817 	struct tegra_nand_controller *ctrl = to_tegra_ctrl(chip->controller);
818 	const struct nand_sdr_timings *timings;
819 
820 	timings = nand_get_sdr_timings(conf);
821 	if (IS_ERR(timings))
822 		return PTR_ERR(timings);
823 
824 	if (csline == NAND_DATA_IFACE_CHECK_ONLY)
825 		return 0;
826 
827 	tegra_nand_setup_timing(ctrl, timings);
828 
829 	return 0;
830 }
831 
832 static const int rs_strength_bootable[] = { 4 };
833 static const int rs_strength[] = { 4, 6, 8 };
834 static const int bch_strength_bootable[] = { 8, 16 };
835 static const int bch_strength[] = { 4, 8, 14, 16 };
836 
837 static int tegra_nand_get_strength(struct nand_chip *chip, const int *strength,
838 				   int strength_len, int bits_per_step,
839 				   int oobsize)
840 {
841 	bool maximize = chip->ecc.options & NAND_ECC_MAXIMIZE;
842 	int i;
843 
844 	/*
845 	 * Loop through available strengths. Backwards in case we try to
846 	 * maximize the BCH strength.
847 	 */
848 	for (i = 0; i < strength_len; i++) {
849 		int strength_sel, bytes_per_step, bytes_per_page;
850 
851 		if (maximize) {
852 			strength_sel = strength[strength_len - i - 1];
853 		} else {
854 			strength_sel = strength[i];
855 
856 			if (strength_sel < chip->base.eccreq.strength)
857 				continue;
858 		}
859 
860 		bytes_per_step = DIV_ROUND_UP(bits_per_step * strength_sel,
861 					      BITS_PER_BYTE);
862 		bytes_per_page = round_up(bytes_per_step * chip->ecc.steps, 4);
863 
864 		/* Check whether strength fits OOB */
865 		if (bytes_per_page < (oobsize - SKIP_SPARE_BYTES))
866 			return strength_sel;
867 	}
868 
869 	return -EINVAL;
870 }
871 
872 static int tegra_nand_select_strength(struct nand_chip *chip, int oobsize)
873 {
874 	const int *strength;
875 	int strength_len, bits_per_step;
876 
877 	switch (chip->ecc.algo) {
878 	case NAND_ECC_RS:
879 		bits_per_step = BITS_PER_STEP_RS;
880 		if (chip->options & NAND_IS_BOOT_MEDIUM) {
881 			strength = rs_strength_bootable;
882 			strength_len = ARRAY_SIZE(rs_strength_bootable);
883 		} else {
884 			strength = rs_strength;
885 			strength_len = ARRAY_SIZE(rs_strength);
886 		}
887 		break;
888 	case NAND_ECC_BCH:
889 		bits_per_step = BITS_PER_STEP_BCH;
890 		if (chip->options & NAND_IS_BOOT_MEDIUM) {
891 			strength = bch_strength_bootable;
892 			strength_len = ARRAY_SIZE(bch_strength_bootable);
893 		} else {
894 			strength = bch_strength;
895 			strength_len = ARRAY_SIZE(bch_strength);
896 		}
897 		break;
898 	default:
899 		return -EINVAL;
900 	}
901 
902 	return tegra_nand_get_strength(chip, strength, strength_len,
903 				       bits_per_step, oobsize);
904 }
905 
906 static int tegra_nand_attach_chip(struct nand_chip *chip)
907 {
908 	struct tegra_nand_controller *ctrl = to_tegra_ctrl(chip->controller);
909 	struct tegra_nand_chip *nand = to_tegra_chip(chip);
910 	struct mtd_info *mtd = nand_to_mtd(chip);
911 	int bits_per_step;
912 	int ret;
913 
914 	if (chip->bbt_options & NAND_BBT_USE_FLASH)
915 		chip->bbt_options |= NAND_BBT_NO_OOB;
916 
917 	chip->ecc.mode = NAND_ECC_HW;
918 	chip->ecc.size = 512;
919 	chip->ecc.steps = mtd->writesize / chip->ecc.size;
920 	if (chip->base.eccreq.step_size != 512) {
921 		dev_err(ctrl->dev, "Unsupported step size %d\n",
922 			chip->base.eccreq.step_size);
923 		return -EINVAL;
924 	}
925 
926 	chip->ecc.read_page = tegra_nand_read_page_hwecc;
927 	chip->ecc.write_page = tegra_nand_write_page_hwecc;
928 	chip->ecc.read_page_raw = tegra_nand_read_page_raw;
929 	chip->ecc.write_page_raw = tegra_nand_write_page_raw;
930 	chip->ecc.read_oob = tegra_nand_read_oob;
931 	chip->ecc.write_oob = tegra_nand_write_oob;
932 
933 	if (chip->options & NAND_BUSWIDTH_16)
934 		nand->config |= CONFIG_BUS_WIDTH_16;
935 
936 	if (chip->ecc.algo == NAND_ECC_UNKNOWN) {
937 		if (mtd->writesize < 2048)
938 			chip->ecc.algo = NAND_ECC_RS;
939 		else
940 			chip->ecc.algo = NAND_ECC_BCH;
941 	}
942 
943 	if (chip->ecc.algo == NAND_ECC_BCH && mtd->writesize < 2048) {
944 		dev_err(ctrl->dev, "BCH supports 2K or 4K page size only\n");
945 		return -EINVAL;
946 	}
947 
948 	if (!chip->ecc.strength) {
949 		ret = tegra_nand_select_strength(chip, mtd->oobsize);
950 		if (ret < 0) {
951 			dev_err(ctrl->dev,
952 				"No valid strength found, minimum %d\n",
953 				chip->base.eccreq.strength);
954 			return ret;
955 		}
956 
957 		chip->ecc.strength = ret;
958 	}
959 
960 	nand->config_ecc = CONFIG_PIPE_EN | CONFIG_SKIP_SPARE |
961 			   CONFIG_SKIP_SPARE_SIZE_4;
962 
963 	switch (chip->ecc.algo) {
964 	case NAND_ECC_RS:
965 		bits_per_step = BITS_PER_STEP_RS * chip->ecc.strength;
966 		mtd_set_ooblayout(mtd, &tegra_nand_oob_rs_ops);
967 		nand->config_ecc |= CONFIG_HW_ECC | CONFIG_ECC_SEL |
968 				    CONFIG_ERR_COR;
969 		switch (chip->ecc.strength) {
970 		case 4:
971 			nand->config_ecc |= CONFIG_TVAL_4;
972 			break;
973 		case 6:
974 			nand->config_ecc |= CONFIG_TVAL_6;
975 			break;
976 		case 8:
977 			nand->config_ecc |= CONFIG_TVAL_8;
978 			break;
979 		default:
980 			dev_err(ctrl->dev, "ECC strength %d not supported\n",
981 				chip->ecc.strength);
982 			return -EINVAL;
983 		}
984 		break;
985 	case NAND_ECC_BCH:
986 		bits_per_step = BITS_PER_STEP_BCH * chip->ecc.strength;
987 		mtd_set_ooblayout(mtd, &tegra_nand_oob_bch_ops);
988 		nand->bch_config = BCH_ENABLE;
989 		switch (chip->ecc.strength) {
990 		case 4:
991 			nand->bch_config |= BCH_TVAL_4;
992 			break;
993 		case 8:
994 			nand->bch_config |= BCH_TVAL_8;
995 			break;
996 		case 14:
997 			nand->bch_config |= BCH_TVAL_14;
998 			break;
999 		case 16:
1000 			nand->bch_config |= BCH_TVAL_16;
1001 			break;
1002 		default:
1003 			dev_err(ctrl->dev, "ECC strength %d not supported\n",
1004 				chip->ecc.strength);
1005 			return -EINVAL;
1006 		}
1007 		break;
1008 	default:
1009 		dev_err(ctrl->dev, "ECC algorithm not supported\n");
1010 		return -EINVAL;
1011 	}
1012 
1013 	dev_info(ctrl->dev, "Using %s with strength %d per 512 byte step\n",
1014 		 chip->ecc.algo == NAND_ECC_BCH ? "BCH" : "RS",
1015 		 chip->ecc.strength);
1016 
1017 	chip->ecc.bytes = DIV_ROUND_UP(bits_per_step, BITS_PER_BYTE);
1018 
1019 	switch (mtd->writesize) {
1020 	case 256:
1021 		nand->config |= CONFIG_PS_256;
1022 		break;
1023 	case 512:
1024 		nand->config |= CONFIG_PS_512;
1025 		break;
1026 	case 1024:
1027 		nand->config |= CONFIG_PS_1024;
1028 		break;
1029 	case 2048:
1030 		nand->config |= CONFIG_PS_2048;
1031 		break;
1032 	case 4096:
1033 		nand->config |= CONFIG_PS_4096;
1034 		break;
1035 	default:
1036 		dev_err(ctrl->dev, "Unsupported writesize %d\n",
1037 			mtd->writesize);
1038 		return -ENODEV;
1039 	}
1040 
1041 	/* Store complete configuration for HW ECC in config_ecc */
1042 	nand->config_ecc |= nand->config;
1043 
1044 	/* Non-HW ECC read/writes complete OOB */
1045 	nand->config |= CONFIG_TAG_BYTE_SIZE(mtd->oobsize - 1);
1046 	writel_relaxed(nand->config, ctrl->regs + CONFIG);
1047 
1048 	return 0;
1049 }
1050 
1051 static const struct nand_controller_ops tegra_nand_controller_ops = {
1052 	.attach_chip = &tegra_nand_attach_chip,
1053 	.exec_op = tegra_nand_exec_op,
1054 	.setup_data_interface = tegra_nand_setup_data_interface,
1055 };
1056 
1057 static int tegra_nand_chips_init(struct device *dev,
1058 				 struct tegra_nand_controller *ctrl)
1059 {
1060 	struct device_node *np = dev->of_node;
1061 	struct device_node *np_nand;
1062 	int nsels, nchips = of_get_child_count(np);
1063 	struct tegra_nand_chip *nand;
1064 	struct mtd_info *mtd;
1065 	struct nand_chip *chip;
1066 	int ret;
1067 	u32 cs;
1068 
1069 	if (nchips != 1) {
1070 		dev_err(dev, "Currently only one NAND chip supported\n");
1071 		return -EINVAL;
1072 	}
1073 
1074 	np_nand = of_get_next_child(np, NULL);
1075 
1076 	nsels = of_property_count_elems_of_size(np_nand, "reg", sizeof(u32));
1077 	if (nsels != 1) {
1078 		dev_err(dev, "Missing/invalid reg property\n");
1079 		return -EINVAL;
1080 	}
1081 
1082 	/* Retrieve CS id, currently only single die NAND supported */
1083 	ret = of_property_read_u32(np_nand, "reg", &cs);
1084 	if (ret) {
1085 		dev_err(dev, "could not retrieve reg property: %d\n", ret);
1086 		return ret;
1087 	}
1088 
1089 	nand = devm_kzalloc(dev, sizeof(*nand), GFP_KERNEL);
1090 	if (!nand)
1091 		return -ENOMEM;
1092 
1093 	nand->cs[0] = cs;
1094 
1095 	nand->wp_gpio = devm_gpiod_get_optional(dev, "wp", GPIOD_OUT_LOW);
1096 
1097 	if (IS_ERR(nand->wp_gpio)) {
1098 		ret = PTR_ERR(nand->wp_gpio);
1099 		dev_err(dev, "Failed to request WP GPIO: %d\n", ret);
1100 		return ret;
1101 	}
1102 
1103 	chip = &nand->chip;
1104 	chip->controller = &ctrl->controller;
1105 
1106 	mtd = nand_to_mtd(chip);
1107 
1108 	mtd->dev.parent = dev;
1109 	mtd->owner = THIS_MODULE;
1110 
1111 	nand_set_flash_node(chip, np_nand);
1112 
1113 	if (!mtd->name)
1114 		mtd->name = "tegra_nand";
1115 
1116 	chip->options = NAND_NO_SUBPAGE_WRITE | NAND_USE_BOUNCE_BUFFER;
1117 
1118 	ret = nand_scan(chip, 1);
1119 	if (ret)
1120 		return ret;
1121 
1122 	mtd_ooblayout_ecc(mtd, 0, &nand->ecc);
1123 
1124 	ret = mtd_device_register(mtd, NULL, 0);
1125 	if (ret) {
1126 		dev_err(dev, "Failed to register mtd device: %d\n", ret);
1127 		nand_cleanup(chip);
1128 		return ret;
1129 	}
1130 
1131 	ctrl->chip = chip;
1132 
1133 	return 0;
1134 }
1135 
1136 static int tegra_nand_probe(struct platform_device *pdev)
1137 {
1138 	struct reset_control *rst;
1139 	struct tegra_nand_controller *ctrl;
1140 	struct resource *res;
1141 	int err = 0;
1142 
1143 	ctrl = devm_kzalloc(&pdev->dev, sizeof(*ctrl), GFP_KERNEL);
1144 	if (!ctrl)
1145 		return -ENOMEM;
1146 
1147 	ctrl->dev = &pdev->dev;
1148 	nand_controller_init(&ctrl->controller);
1149 	ctrl->controller.ops = &tegra_nand_controller_ops;
1150 
1151 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1152 	ctrl->regs = devm_ioremap_resource(&pdev->dev, res);
1153 	if (IS_ERR(ctrl->regs))
1154 		return PTR_ERR(ctrl->regs);
1155 
1156 	rst = devm_reset_control_get(&pdev->dev, "nand");
1157 	if (IS_ERR(rst))
1158 		return PTR_ERR(rst);
1159 
1160 	ctrl->clk = devm_clk_get(&pdev->dev, "nand");
1161 	if (IS_ERR(ctrl->clk))
1162 		return PTR_ERR(ctrl->clk);
1163 
1164 	err = clk_prepare_enable(ctrl->clk);
1165 	if (err)
1166 		return err;
1167 
1168 	err = reset_control_reset(rst);
1169 	if (err) {
1170 		dev_err(ctrl->dev, "Failed to reset HW: %d\n", err);
1171 		goto err_disable_clk;
1172 	}
1173 
1174 	writel_relaxed(HWSTATUS_CMD_DEFAULT, ctrl->regs + HWSTATUS_CMD);
1175 	writel_relaxed(HWSTATUS_MASK_DEFAULT, ctrl->regs + HWSTATUS_MASK);
1176 	writel_relaxed(INT_MASK, ctrl->regs + IER);
1177 
1178 	init_completion(&ctrl->command_complete);
1179 	init_completion(&ctrl->dma_complete);
1180 
1181 	ctrl->irq = platform_get_irq(pdev, 0);
1182 	err = devm_request_irq(&pdev->dev, ctrl->irq, tegra_nand_irq, 0,
1183 			       dev_name(&pdev->dev), ctrl);
1184 	if (err) {
1185 		dev_err(ctrl->dev, "Failed to get IRQ: %d\n", err);
1186 		goto err_disable_clk;
1187 	}
1188 
1189 	writel_relaxed(DMA_MST_CTRL_IS_DONE, ctrl->regs + DMA_MST_CTRL);
1190 
1191 	err = tegra_nand_chips_init(ctrl->dev, ctrl);
1192 	if (err)
1193 		goto err_disable_clk;
1194 
1195 	platform_set_drvdata(pdev, ctrl);
1196 
1197 	return 0;
1198 
1199 err_disable_clk:
1200 	clk_disable_unprepare(ctrl->clk);
1201 	return err;
1202 }
1203 
1204 static int tegra_nand_remove(struct platform_device *pdev)
1205 {
1206 	struct tegra_nand_controller *ctrl = platform_get_drvdata(pdev);
1207 	struct nand_chip *chip = ctrl->chip;
1208 	struct mtd_info *mtd = nand_to_mtd(chip);
1209 	int ret;
1210 
1211 	ret = mtd_device_unregister(mtd);
1212 	if (ret)
1213 		return ret;
1214 
1215 	nand_cleanup(chip);
1216 
1217 	clk_disable_unprepare(ctrl->clk);
1218 
1219 	return 0;
1220 }
1221 
1222 static const struct of_device_id tegra_nand_of_match[] = {
1223 	{ .compatible = "nvidia,tegra20-nand" },
1224 	{ /* sentinel */ }
1225 };
1226 MODULE_DEVICE_TABLE(of, tegra_nand_of_match);
1227 
1228 static struct platform_driver tegra_nand_driver = {
1229 	.driver = {
1230 		.name = "tegra-nand",
1231 		.of_match_table = tegra_nand_of_match,
1232 	},
1233 	.probe = tegra_nand_probe,
1234 	.remove = tegra_nand_remove,
1235 };
1236 module_platform_driver(tegra_nand_driver);
1237 
1238 MODULE_DESCRIPTION("NVIDIA Tegra NAND driver");
1239 MODULE_AUTHOR("Thierry Reding <thierry.reding@nvidia.com>");
1240 MODULE_AUTHOR("Lucas Stach <dev@lynxeye.de>");
1241 MODULE_AUTHOR("Stefan Agner <stefan@agner.ch>");
1242 MODULE_LICENSE("GPL v2");
1243