xref: /openbmc/linux/drivers/mtd/nand/raw/mtk_nand.c (revision f5ad1c74)
1 // SPDX-License-Identifier: GPL-2.0 OR MIT
2 /*
3  * MTK NAND Flash controller driver.
4  * Copyright (C) 2016 MediaTek Inc.
5  * Authors:	Xiaolei Li		<xiaolei.li@mediatek.com>
6  *		Jorge Ramirez-Ortiz	<jorge.ramirez-ortiz@linaro.org>
7  */
8 
9 #include <linux/platform_device.h>
10 #include <linux/dma-mapping.h>
11 #include <linux/interrupt.h>
12 #include <linux/delay.h>
13 #include <linux/clk.h>
14 #include <linux/mtd/rawnand.h>
15 #include <linux/mtd/mtd.h>
16 #include <linux/module.h>
17 #include <linux/iopoll.h>
18 #include <linux/of.h>
19 #include <linux/of_device.h>
20 #include "mtk_ecc.h"
21 
22 /* NAND controller register definition */
23 #define NFI_CNFG		(0x00)
24 #define		CNFG_AHB		BIT(0)
25 #define		CNFG_READ_EN		BIT(1)
26 #define		CNFG_DMA_BURST_EN	BIT(2)
27 #define		CNFG_BYTE_RW		BIT(6)
28 #define		CNFG_HW_ECC_EN		BIT(8)
29 #define		CNFG_AUTO_FMT_EN	BIT(9)
30 #define		CNFG_OP_CUST		(6 << 12)
31 #define NFI_PAGEFMT		(0x04)
32 #define		PAGEFMT_FDM_ECC_SHIFT	(12)
33 #define		PAGEFMT_FDM_SHIFT	(8)
34 #define		PAGEFMT_SEC_SEL_512	BIT(2)
35 #define		PAGEFMT_512_2K		(0)
36 #define		PAGEFMT_2K_4K		(1)
37 #define		PAGEFMT_4K_8K		(2)
38 #define		PAGEFMT_8K_16K		(3)
39 /* NFI control */
40 #define NFI_CON			(0x08)
41 #define		CON_FIFO_FLUSH		BIT(0)
42 #define		CON_NFI_RST		BIT(1)
43 #define		CON_BRD			BIT(8)  /* burst  read */
44 #define		CON_BWR			BIT(9)	/* burst  write */
45 #define		CON_SEC_SHIFT		(12)
46 /* Timming control register */
47 #define NFI_ACCCON		(0x0C)
48 #define NFI_INTR_EN		(0x10)
49 #define		INTR_AHB_DONE_EN	BIT(6)
50 #define NFI_INTR_STA		(0x14)
51 #define NFI_CMD			(0x20)
52 #define NFI_ADDRNOB		(0x30)
53 #define NFI_COLADDR		(0x34)
54 #define NFI_ROWADDR		(0x38)
55 #define NFI_STRDATA		(0x40)
56 #define		STAR_EN			(1)
57 #define		STAR_DE			(0)
58 #define NFI_CNRNB		(0x44)
59 #define NFI_DATAW		(0x50)
60 #define NFI_DATAR		(0x54)
61 #define NFI_PIO_DIRDY		(0x58)
62 #define		PIO_DI_RDY		(0x01)
63 #define NFI_STA			(0x60)
64 #define		STA_CMD			BIT(0)
65 #define		STA_ADDR		BIT(1)
66 #define		STA_BUSY		BIT(8)
67 #define		STA_EMP_PAGE		BIT(12)
68 #define		NFI_FSM_CUSTDATA	(0xe << 16)
69 #define		NFI_FSM_MASK		(0xf << 16)
70 #define NFI_ADDRCNTR		(0x70)
71 #define		CNTR_MASK		GENMASK(16, 12)
72 #define		ADDRCNTR_SEC_SHIFT	(12)
73 #define		ADDRCNTR_SEC(val) \
74 		(((val) & CNTR_MASK) >> ADDRCNTR_SEC_SHIFT)
75 #define NFI_STRADDR		(0x80)
76 #define NFI_BYTELEN		(0x84)
77 #define NFI_CSEL		(0x90)
78 #define NFI_FDML(x)		(0xA0 + (x) * sizeof(u32) * 2)
79 #define NFI_FDMM(x)		(0xA4 + (x) * sizeof(u32) * 2)
80 #define NFI_FDM_MAX_SIZE	(8)
81 #define NFI_FDM_MIN_SIZE	(1)
82 #define NFI_DEBUG_CON1		(0x220)
83 #define		STROBE_MASK		GENMASK(4, 3)
84 #define		STROBE_SHIFT		(3)
85 #define		MAX_STROBE_DLY		(3)
86 #define NFI_MASTER_STA		(0x224)
87 #define		MASTER_STA_MASK		(0x0FFF)
88 #define NFI_EMPTY_THRESH	(0x23C)
89 
90 #define MTK_NAME		"mtk-nand"
91 #define KB(x)			((x) * 1024UL)
92 #define MB(x)			(KB(x) * 1024UL)
93 
94 #define MTK_TIMEOUT		(500000)
95 #define MTK_RESET_TIMEOUT	(1000000)
96 #define MTK_NAND_MAX_NSELS	(2)
97 #define MTK_NFC_MIN_SPARE	(16)
98 #define ACCTIMING(tpoecs, tprecs, tc2r, tw2r, twh, twst, trlt) \
99 	((tpoecs) << 28 | (tprecs) << 22 | (tc2r) << 16 | \
100 	(tw2r) << 12 | (twh) << 8 | (twst) << 4 | (trlt))
101 
102 struct mtk_nfc_caps {
103 	const u8 *spare_size;
104 	u8 num_spare_size;
105 	u8 pageformat_spare_shift;
106 	u8 nfi_clk_div;
107 	u8 max_sector;
108 	u32 max_sector_size;
109 };
110 
111 struct mtk_nfc_bad_mark_ctl {
112 	void (*bm_swap)(struct mtd_info *, u8 *buf, int raw);
113 	u32 sec;
114 	u32 pos;
115 };
116 
117 /*
118  * FDM: region used to store free OOB data
119  */
120 struct mtk_nfc_fdm {
121 	u32 reg_size;
122 	u32 ecc_size;
123 };
124 
125 struct mtk_nfc_nand_chip {
126 	struct list_head node;
127 	struct nand_chip nand;
128 
129 	struct mtk_nfc_bad_mark_ctl bad_mark;
130 	struct mtk_nfc_fdm fdm;
131 	u32 spare_per_sector;
132 
133 	int nsels;
134 	u8 sels[];
135 	/* nothing after this field */
136 };
137 
138 struct mtk_nfc_clk {
139 	struct clk *nfi_clk;
140 	struct clk *pad_clk;
141 };
142 
143 struct mtk_nfc {
144 	struct nand_controller controller;
145 	struct mtk_ecc_config ecc_cfg;
146 	struct mtk_nfc_clk clk;
147 	struct mtk_ecc *ecc;
148 
149 	struct device *dev;
150 	const struct mtk_nfc_caps *caps;
151 	void __iomem *regs;
152 
153 	struct completion done;
154 	struct list_head chips;
155 
156 	u8 *buffer;
157 
158 	unsigned long assigned_cs;
159 };
160 
161 /*
162  * supported spare size of each IP.
163  * order should be the same with the spare size bitfiled defination of
164  * register NFI_PAGEFMT.
165  */
166 static const u8 spare_size_mt2701[] = {
167 	16, 26, 27, 28, 32, 36, 40, 44,	48, 49, 50, 51, 52, 62, 63, 64
168 };
169 
170 static const u8 spare_size_mt2712[] = {
171 	16, 26, 27, 28, 32, 36, 40, 44, 48, 49, 50, 51, 52, 62, 61, 63, 64, 67,
172 	74
173 };
174 
175 static const u8 spare_size_mt7622[] = {
176 	16, 26, 27, 28
177 };
178 
179 static inline struct mtk_nfc_nand_chip *to_mtk_nand(struct nand_chip *nand)
180 {
181 	return container_of(nand, struct mtk_nfc_nand_chip, nand);
182 }
183 
184 static inline u8 *data_ptr(struct nand_chip *chip, const u8 *p, int i)
185 {
186 	return (u8 *)p + i * chip->ecc.size;
187 }
188 
189 static inline u8 *oob_ptr(struct nand_chip *chip, int i)
190 {
191 	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
192 	u8 *poi;
193 
194 	/* map the sector's FDM data to free oob:
195 	 * the beginning of the oob area stores the FDM data of bad mark sectors
196 	 */
197 
198 	if (i < mtk_nand->bad_mark.sec)
199 		poi = chip->oob_poi + (i + 1) * mtk_nand->fdm.reg_size;
200 	else if (i == mtk_nand->bad_mark.sec)
201 		poi = chip->oob_poi;
202 	else
203 		poi = chip->oob_poi + i * mtk_nand->fdm.reg_size;
204 
205 	return poi;
206 }
207 
208 static inline int mtk_data_len(struct nand_chip *chip)
209 {
210 	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
211 
212 	return chip->ecc.size + mtk_nand->spare_per_sector;
213 }
214 
215 static inline u8 *mtk_data_ptr(struct nand_chip *chip,  int i)
216 {
217 	struct mtk_nfc *nfc = nand_get_controller_data(chip);
218 
219 	return nfc->buffer + i * mtk_data_len(chip);
220 }
221 
222 static inline u8 *mtk_oob_ptr(struct nand_chip *chip, int i)
223 {
224 	struct mtk_nfc *nfc = nand_get_controller_data(chip);
225 
226 	return nfc->buffer + i * mtk_data_len(chip) + chip->ecc.size;
227 }
228 
229 static inline void nfi_writel(struct mtk_nfc *nfc, u32 val, u32 reg)
230 {
231 	writel(val, nfc->regs + reg);
232 }
233 
234 static inline void nfi_writew(struct mtk_nfc *nfc, u16 val, u32 reg)
235 {
236 	writew(val, nfc->regs + reg);
237 }
238 
239 static inline void nfi_writeb(struct mtk_nfc *nfc, u8 val, u32 reg)
240 {
241 	writeb(val, nfc->regs + reg);
242 }
243 
244 static inline u32 nfi_readl(struct mtk_nfc *nfc, u32 reg)
245 {
246 	return readl_relaxed(nfc->regs + reg);
247 }
248 
249 static inline u16 nfi_readw(struct mtk_nfc *nfc, u32 reg)
250 {
251 	return readw_relaxed(nfc->regs + reg);
252 }
253 
254 static inline u8 nfi_readb(struct mtk_nfc *nfc, u32 reg)
255 {
256 	return readb_relaxed(nfc->regs + reg);
257 }
258 
259 static void mtk_nfc_hw_reset(struct mtk_nfc *nfc)
260 {
261 	struct device *dev = nfc->dev;
262 	u32 val;
263 	int ret;
264 
265 	/* reset all registers and force the NFI master to terminate */
266 	nfi_writel(nfc, CON_FIFO_FLUSH | CON_NFI_RST, NFI_CON);
267 
268 	/* wait for the master to finish the last transaction */
269 	ret = readl_poll_timeout(nfc->regs + NFI_MASTER_STA, val,
270 				 !(val & MASTER_STA_MASK), 50,
271 				 MTK_RESET_TIMEOUT);
272 	if (ret)
273 		dev_warn(dev, "master active in reset [0x%x] = 0x%x\n",
274 			 NFI_MASTER_STA, val);
275 
276 	/* ensure any status register affected by the NFI master is reset */
277 	nfi_writel(nfc, CON_FIFO_FLUSH | CON_NFI_RST, NFI_CON);
278 	nfi_writew(nfc, STAR_DE, NFI_STRDATA);
279 }
280 
281 static int mtk_nfc_send_command(struct mtk_nfc *nfc, u8 command)
282 {
283 	struct device *dev = nfc->dev;
284 	u32 val;
285 	int ret;
286 
287 	nfi_writel(nfc, command, NFI_CMD);
288 
289 	ret = readl_poll_timeout_atomic(nfc->regs + NFI_STA, val,
290 					!(val & STA_CMD), 10,  MTK_TIMEOUT);
291 	if (ret) {
292 		dev_warn(dev, "nfi core timed out entering command mode\n");
293 		return -EIO;
294 	}
295 
296 	return 0;
297 }
298 
299 static int mtk_nfc_send_address(struct mtk_nfc *nfc, int addr)
300 {
301 	struct device *dev = nfc->dev;
302 	u32 val;
303 	int ret;
304 
305 	nfi_writel(nfc, addr, NFI_COLADDR);
306 	nfi_writel(nfc, 0, NFI_ROWADDR);
307 	nfi_writew(nfc, 1, NFI_ADDRNOB);
308 
309 	ret = readl_poll_timeout_atomic(nfc->regs + NFI_STA, val,
310 					!(val & STA_ADDR), 10, MTK_TIMEOUT);
311 	if (ret) {
312 		dev_warn(dev, "nfi core timed out entering address mode\n");
313 		return -EIO;
314 	}
315 
316 	return 0;
317 }
318 
319 static int mtk_nfc_hw_runtime_config(struct mtd_info *mtd)
320 {
321 	struct nand_chip *chip = mtd_to_nand(mtd);
322 	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
323 	struct mtk_nfc *nfc = nand_get_controller_data(chip);
324 	u32 fmt, spare, i;
325 
326 	if (!mtd->writesize)
327 		return 0;
328 
329 	spare = mtk_nand->spare_per_sector;
330 
331 	switch (mtd->writesize) {
332 	case 512:
333 		fmt = PAGEFMT_512_2K | PAGEFMT_SEC_SEL_512;
334 		break;
335 	case KB(2):
336 		if (chip->ecc.size == 512)
337 			fmt = PAGEFMT_2K_4K | PAGEFMT_SEC_SEL_512;
338 		else
339 			fmt = PAGEFMT_512_2K;
340 		break;
341 	case KB(4):
342 		if (chip->ecc.size == 512)
343 			fmt = PAGEFMT_4K_8K | PAGEFMT_SEC_SEL_512;
344 		else
345 			fmt = PAGEFMT_2K_4K;
346 		break;
347 	case KB(8):
348 		if (chip->ecc.size == 512)
349 			fmt = PAGEFMT_8K_16K | PAGEFMT_SEC_SEL_512;
350 		else
351 			fmt = PAGEFMT_4K_8K;
352 		break;
353 	case KB(16):
354 		fmt = PAGEFMT_8K_16K;
355 		break;
356 	default:
357 		dev_err(nfc->dev, "invalid page len: %d\n", mtd->writesize);
358 		return -EINVAL;
359 	}
360 
361 	/*
362 	 * the hardware will double the value for this eccsize, so we need to
363 	 * halve it
364 	 */
365 	if (chip->ecc.size == 1024)
366 		spare >>= 1;
367 
368 	for (i = 0; i < nfc->caps->num_spare_size; i++) {
369 		if (nfc->caps->spare_size[i] == spare)
370 			break;
371 	}
372 
373 	if (i == nfc->caps->num_spare_size) {
374 		dev_err(nfc->dev, "invalid spare size %d\n", spare);
375 		return -EINVAL;
376 	}
377 
378 	fmt |= i << nfc->caps->pageformat_spare_shift;
379 
380 	fmt |= mtk_nand->fdm.reg_size << PAGEFMT_FDM_SHIFT;
381 	fmt |= mtk_nand->fdm.ecc_size << PAGEFMT_FDM_ECC_SHIFT;
382 	nfi_writel(nfc, fmt, NFI_PAGEFMT);
383 
384 	nfc->ecc_cfg.strength = chip->ecc.strength;
385 	nfc->ecc_cfg.len = chip->ecc.size + mtk_nand->fdm.ecc_size;
386 
387 	return 0;
388 }
389 
390 static inline void mtk_nfc_wait_ioready(struct mtk_nfc *nfc)
391 {
392 	int rc;
393 	u8 val;
394 
395 	rc = readb_poll_timeout_atomic(nfc->regs + NFI_PIO_DIRDY, val,
396 				       val & PIO_DI_RDY, 10, MTK_TIMEOUT);
397 	if (rc < 0)
398 		dev_err(nfc->dev, "data not ready\n");
399 }
400 
401 static inline u8 mtk_nfc_read_byte(struct nand_chip *chip)
402 {
403 	struct mtk_nfc *nfc = nand_get_controller_data(chip);
404 	u32 reg;
405 
406 	/* after each byte read, the NFI_STA reg is reset by the hardware */
407 	reg = nfi_readl(nfc, NFI_STA) & NFI_FSM_MASK;
408 	if (reg != NFI_FSM_CUSTDATA) {
409 		reg = nfi_readw(nfc, NFI_CNFG);
410 		reg |= CNFG_BYTE_RW | CNFG_READ_EN;
411 		nfi_writew(nfc, reg, NFI_CNFG);
412 
413 		/*
414 		 * set to max sector to allow the HW to continue reading over
415 		 * unaligned accesses
416 		 */
417 		reg = (nfc->caps->max_sector << CON_SEC_SHIFT) | CON_BRD;
418 		nfi_writel(nfc, reg, NFI_CON);
419 
420 		/* trigger to fetch data */
421 		nfi_writew(nfc, STAR_EN, NFI_STRDATA);
422 	}
423 
424 	mtk_nfc_wait_ioready(nfc);
425 
426 	return nfi_readb(nfc, NFI_DATAR);
427 }
428 
429 static void mtk_nfc_read_buf(struct nand_chip *chip, u8 *buf, int len)
430 {
431 	int i;
432 
433 	for (i = 0; i < len; i++)
434 		buf[i] = mtk_nfc_read_byte(chip);
435 }
436 
437 static void mtk_nfc_write_byte(struct nand_chip *chip, u8 byte)
438 {
439 	struct mtk_nfc *nfc = nand_get_controller_data(chip);
440 	u32 reg;
441 
442 	reg = nfi_readl(nfc, NFI_STA) & NFI_FSM_MASK;
443 
444 	if (reg != NFI_FSM_CUSTDATA) {
445 		reg = nfi_readw(nfc, NFI_CNFG) | CNFG_BYTE_RW;
446 		nfi_writew(nfc, reg, NFI_CNFG);
447 
448 		reg = nfc->caps->max_sector << CON_SEC_SHIFT | CON_BWR;
449 		nfi_writel(nfc, reg, NFI_CON);
450 
451 		nfi_writew(nfc, STAR_EN, NFI_STRDATA);
452 	}
453 
454 	mtk_nfc_wait_ioready(nfc);
455 	nfi_writeb(nfc, byte, NFI_DATAW);
456 }
457 
458 static void mtk_nfc_write_buf(struct nand_chip *chip, const u8 *buf, int len)
459 {
460 	int i;
461 
462 	for (i = 0; i < len; i++)
463 		mtk_nfc_write_byte(chip, buf[i]);
464 }
465 
466 static int mtk_nfc_exec_instr(struct nand_chip *chip,
467 			      const struct nand_op_instr *instr)
468 {
469 	struct mtk_nfc *nfc = nand_get_controller_data(chip);
470 	unsigned int i;
471 	u32 status;
472 
473 	switch (instr->type) {
474 	case NAND_OP_CMD_INSTR:
475 		mtk_nfc_send_command(nfc, instr->ctx.cmd.opcode);
476 		return 0;
477 	case NAND_OP_ADDR_INSTR:
478 		for (i = 0; i < instr->ctx.addr.naddrs; i++)
479 			mtk_nfc_send_address(nfc, instr->ctx.addr.addrs[i]);
480 		return 0;
481 	case NAND_OP_DATA_IN_INSTR:
482 		mtk_nfc_read_buf(chip, instr->ctx.data.buf.in,
483 				 instr->ctx.data.len);
484 		return 0;
485 	case NAND_OP_DATA_OUT_INSTR:
486 		mtk_nfc_write_buf(chip, instr->ctx.data.buf.out,
487 				  instr->ctx.data.len);
488 		return 0;
489 	case NAND_OP_WAITRDY_INSTR:
490 		return readl_poll_timeout(nfc->regs + NFI_STA, status,
491 					  status & STA_BUSY, 20,
492 					  instr->ctx.waitrdy.timeout_ms);
493 	default:
494 		break;
495 	}
496 
497 	return -EINVAL;
498 }
499 
500 static void mtk_nfc_select_target(struct nand_chip *nand, unsigned int cs)
501 {
502 	struct mtk_nfc *nfc = nand_get_controller_data(nand);
503 	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(nand);
504 
505 	mtk_nfc_hw_runtime_config(nand_to_mtd(nand));
506 
507 	nfi_writel(nfc, mtk_nand->sels[cs], NFI_CSEL);
508 }
509 
510 static int mtk_nfc_exec_op(struct nand_chip *chip,
511 			   const struct nand_operation *op,
512 			   bool check_only)
513 {
514 	struct mtk_nfc *nfc = nand_get_controller_data(chip);
515 	unsigned int i;
516 	int ret = 0;
517 
518 	if (check_only)
519 		return 0;
520 
521 	mtk_nfc_hw_reset(nfc);
522 	nfi_writew(nfc, CNFG_OP_CUST, NFI_CNFG);
523 	mtk_nfc_select_target(chip, op->cs);
524 
525 	for (i = 0; i < op->ninstrs; i++) {
526 		ret = mtk_nfc_exec_instr(chip, &op->instrs[i]);
527 		if (ret)
528 			break;
529 	}
530 
531 	return ret;
532 }
533 
534 static int mtk_nfc_setup_interface(struct nand_chip *chip, int csline,
535 				   const struct nand_interface_config *conf)
536 {
537 	struct mtk_nfc *nfc = nand_get_controller_data(chip);
538 	const struct nand_sdr_timings *timings;
539 	u32 rate, tpoecs, tprecs, tc2r, tw2r, twh, twst = 0, trlt = 0;
540 	u32 temp, tsel = 0;
541 
542 	timings = nand_get_sdr_timings(conf);
543 	if (IS_ERR(timings))
544 		return -ENOTSUPP;
545 
546 	if (csline == NAND_DATA_IFACE_CHECK_ONLY)
547 		return 0;
548 
549 	rate = clk_get_rate(nfc->clk.nfi_clk);
550 	/* There is a frequency divider in some IPs */
551 	rate /= nfc->caps->nfi_clk_div;
552 
553 	/* turn clock rate into KHZ */
554 	rate /= 1000;
555 
556 	tpoecs = max(timings->tALH_min, timings->tCLH_min) / 1000;
557 	tpoecs = DIV_ROUND_UP(tpoecs * rate, 1000000);
558 	tpoecs &= 0xf;
559 
560 	tprecs = max(timings->tCLS_min, timings->tALS_min) / 1000;
561 	tprecs = DIV_ROUND_UP(tprecs * rate, 1000000);
562 	tprecs &= 0x3f;
563 
564 	/* sdr interface has no tCR which means CE# low to RE# low */
565 	tc2r = 0;
566 
567 	tw2r = timings->tWHR_min / 1000;
568 	tw2r = DIV_ROUND_UP(tw2r * rate, 1000000);
569 	tw2r = DIV_ROUND_UP(tw2r - 1, 2);
570 	tw2r &= 0xf;
571 
572 	twh = max(timings->tREH_min, timings->tWH_min) / 1000;
573 	twh = DIV_ROUND_UP(twh * rate, 1000000) - 1;
574 	twh &= 0xf;
575 
576 	/* Calculate real WE#/RE# hold time in nanosecond */
577 	temp = (twh + 1) * 1000000 / rate;
578 	/* nanosecond to picosecond */
579 	temp *= 1000;
580 
581 	/*
582 	 * WE# low level time should be expaned to meet WE# pulse time
583 	 * and WE# cycle time at the same time.
584 	 */
585 	if (temp < timings->tWC_min)
586 		twst = timings->tWC_min - temp;
587 	twst = max(timings->tWP_min, twst) / 1000;
588 	twst = DIV_ROUND_UP(twst * rate, 1000000) - 1;
589 	twst &= 0xf;
590 
591 	/*
592 	 * RE# low level time should be expaned to meet RE# pulse time
593 	 * and RE# cycle time at the same time.
594 	 */
595 	if (temp < timings->tRC_min)
596 		trlt = timings->tRC_min - temp;
597 	trlt = max(trlt, timings->tRP_min) / 1000;
598 	trlt = DIV_ROUND_UP(trlt * rate, 1000000) - 1;
599 	trlt &= 0xf;
600 
601 	/* Calculate RE# pulse time in nanosecond. */
602 	temp = (trlt + 1) * 1000000 / rate;
603 	/* nanosecond to picosecond */
604 	temp *= 1000;
605 	/*
606 	 * If RE# access time is bigger than RE# pulse time,
607 	 * delay sampling data timing.
608 	 */
609 	if (temp < timings->tREA_max) {
610 		tsel = timings->tREA_max / 1000;
611 		tsel = DIV_ROUND_UP(tsel * rate, 1000000);
612 		tsel -= (trlt + 1);
613 		if (tsel > MAX_STROBE_DLY) {
614 			trlt += tsel - MAX_STROBE_DLY;
615 			tsel = MAX_STROBE_DLY;
616 		}
617 	}
618 	temp = nfi_readl(nfc, NFI_DEBUG_CON1);
619 	temp &= ~STROBE_MASK;
620 	temp |= tsel << STROBE_SHIFT;
621 	nfi_writel(nfc, temp, NFI_DEBUG_CON1);
622 
623 	/*
624 	 * ACCON: access timing control register
625 	 * -------------------------------------
626 	 * 31:28: tpoecs, minimum required time for CS post pulling down after
627 	 *        accessing the device
628 	 * 27:22: tprecs, minimum required time for CS pre pulling down before
629 	 *        accessing the device
630 	 * 21:16: tc2r, minimum required time from NCEB low to NREB low
631 	 * 15:12: tw2r, minimum required time from NWEB high to NREB low.
632 	 * 11:08: twh, write enable hold time
633 	 * 07:04: twst, write wait states
634 	 * 03:00: trlt, read wait states
635 	 */
636 	trlt = ACCTIMING(tpoecs, tprecs, tc2r, tw2r, twh, twst, trlt);
637 	nfi_writel(nfc, trlt, NFI_ACCCON);
638 
639 	return 0;
640 }
641 
642 static int mtk_nfc_sector_encode(struct nand_chip *chip, u8 *data)
643 {
644 	struct mtk_nfc *nfc = nand_get_controller_data(chip);
645 	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
646 	int size = chip->ecc.size + mtk_nand->fdm.reg_size;
647 
648 	nfc->ecc_cfg.mode = ECC_DMA_MODE;
649 	nfc->ecc_cfg.op = ECC_ENCODE;
650 
651 	return mtk_ecc_encode(nfc->ecc, &nfc->ecc_cfg, data, size);
652 }
653 
654 static void mtk_nfc_no_bad_mark_swap(struct mtd_info *a, u8 *b, int c)
655 {
656 	/* nop */
657 }
658 
659 static void mtk_nfc_bad_mark_swap(struct mtd_info *mtd, u8 *buf, int raw)
660 {
661 	struct nand_chip *chip = mtd_to_nand(mtd);
662 	struct mtk_nfc_nand_chip *nand = to_mtk_nand(chip);
663 	u32 bad_pos = nand->bad_mark.pos;
664 
665 	if (raw)
666 		bad_pos += nand->bad_mark.sec * mtk_data_len(chip);
667 	else
668 		bad_pos += nand->bad_mark.sec * chip->ecc.size;
669 
670 	swap(chip->oob_poi[0], buf[bad_pos]);
671 }
672 
673 static int mtk_nfc_format_subpage(struct mtd_info *mtd, u32 offset,
674 				  u32 len, const u8 *buf)
675 {
676 	struct nand_chip *chip = mtd_to_nand(mtd);
677 	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
678 	struct mtk_nfc *nfc = nand_get_controller_data(chip);
679 	struct mtk_nfc_fdm *fdm = &mtk_nand->fdm;
680 	u32 start, end;
681 	int i, ret;
682 
683 	start = offset / chip->ecc.size;
684 	end = DIV_ROUND_UP(offset + len, chip->ecc.size);
685 
686 	memset(nfc->buffer, 0xff, mtd->writesize + mtd->oobsize);
687 	for (i = 0; i < chip->ecc.steps; i++) {
688 		memcpy(mtk_data_ptr(chip, i), data_ptr(chip, buf, i),
689 		       chip->ecc.size);
690 
691 		if (start > i || i >= end)
692 			continue;
693 
694 		if (i == mtk_nand->bad_mark.sec)
695 			mtk_nand->bad_mark.bm_swap(mtd, nfc->buffer, 1);
696 
697 		memcpy(mtk_oob_ptr(chip, i), oob_ptr(chip, i), fdm->reg_size);
698 
699 		/* program the CRC back to the OOB */
700 		ret = mtk_nfc_sector_encode(chip, mtk_data_ptr(chip, i));
701 		if (ret < 0)
702 			return ret;
703 	}
704 
705 	return 0;
706 }
707 
708 static void mtk_nfc_format_page(struct mtd_info *mtd, const u8 *buf)
709 {
710 	struct nand_chip *chip = mtd_to_nand(mtd);
711 	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
712 	struct mtk_nfc *nfc = nand_get_controller_data(chip);
713 	struct mtk_nfc_fdm *fdm = &mtk_nand->fdm;
714 	u32 i;
715 
716 	memset(nfc->buffer, 0xff, mtd->writesize + mtd->oobsize);
717 	for (i = 0; i < chip->ecc.steps; i++) {
718 		if (buf)
719 			memcpy(mtk_data_ptr(chip, i), data_ptr(chip, buf, i),
720 			       chip->ecc.size);
721 
722 		if (i == mtk_nand->bad_mark.sec)
723 			mtk_nand->bad_mark.bm_swap(mtd, nfc->buffer, 1);
724 
725 		memcpy(mtk_oob_ptr(chip, i), oob_ptr(chip, i), fdm->reg_size);
726 	}
727 }
728 
729 static inline void mtk_nfc_read_fdm(struct nand_chip *chip, u32 start,
730 				    u32 sectors)
731 {
732 	struct mtk_nfc *nfc = nand_get_controller_data(chip);
733 	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
734 	struct mtk_nfc_fdm *fdm = &mtk_nand->fdm;
735 	u32 vall, valm;
736 	u8 *oobptr;
737 	int i, j;
738 
739 	for (i = 0; i < sectors; i++) {
740 		oobptr = oob_ptr(chip, start + i);
741 		vall = nfi_readl(nfc, NFI_FDML(i));
742 		valm = nfi_readl(nfc, NFI_FDMM(i));
743 
744 		for (j = 0; j < fdm->reg_size; j++)
745 			oobptr[j] = (j >= 4 ? valm : vall) >> ((j % 4) * 8);
746 	}
747 }
748 
749 static inline void mtk_nfc_write_fdm(struct nand_chip *chip)
750 {
751 	struct mtk_nfc *nfc = nand_get_controller_data(chip);
752 	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
753 	struct mtk_nfc_fdm *fdm = &mtk_nand->fdm;
754 	u32 vall, valm;
755 	u8 *oobptr;
756 	int i, j;
757 
758 	for (i = 0; i < chip->ecc.steps; i++) {
759 		oobptr = oob_ptr(chip, i);
760 		vall = 0;
761 		valm = 0;
762 		for (j = 0; j < 8; j++) {
763 			if (j < 4)
764 				vall |= (j < fdm->reg_size ? oobptr[j] : 0xff)
765 						<< (j * 8);
766 			else
767 				valm |= (j < fdm->reg_size ? oobptr[j] : 0xff)
768 						<< ((j - 4) * 8);
769 		}
770 		nfi_writel(nfc, vall, NFI_FDML(i));
771 		nfi_writel(nfc, valm, NFI_FDMM(i));
772 	}
773 }
774 
775 static int mtk_nfc_do_write_page(struct mtd_info *mtd, struct nand_chip *chip,
776 				 const u8 *buf, int page, int len)
777 {
778 	struct mtk_nfc *nfc = nand_get_controller_data(chip);
779 	struct device *dev = nfc->dev;
780 	dma_addr_t addr;
781 	u32 reg;
782 	int ret;
783 
784 	addr = dma_map_single(dev, (void *)buf, len, DMA_TO_DEVICE);
785 	ret = dma_mapping_error(nfc->dev, addr);
786 	if (ret) {
787 		dev_err(nfc->dev, "dma mapping error\n");
788 		return -EINVAL;
789 	}
790 
791 	reg = nfi_readw(nfc, NFI_CNFG) | CNFG_AHB | CNFG_DMA_BURST_EN;
792 	nfi_writew(nfc, reg, NFI_CNFG);
793 
794 	nfi_writel(nfc, chip->ecc.steps << CON_SEC_SHIFT, NFI_CON);
795 	nfi_writel(nfc, lower_32_bits(addr), NFI_STRADDR);
796 	nfi_writew(nfc, INTR_AHB_DONE_EN, NFI_INTR_EN);
797 
798 	init_completion(&nfc->done);
799 
800 	reg = nfi_readl(nfc, NFI_CON) | CON_BWR;
801 	nfi_writel(nfc, reg, NFI_CON);
802 	nfi_writew(nfc, STAR_EN, NFI_STRDATA);
803 
804 	ret = wait_for_completion_timeout(&nfc->done, msecs_to_jiffies(500));
805 	if (!ret) {
806 		dev_err(dev, "program ahb done timeout\n");
807 		nfi_writew(nfc, 0, NFI_INTR_EN);
808 		ret = -ETIMEDOUT;
809 		goto timeout;
810 	}
811 
812 	ret = readl_poll_timeout_atomic(nfc->regs + NFI_ADDRCNTR, reg,
813 					ADDRCNTR_SEC(reg) >= chip->ecc.steps,
814 					10, MTK_TIMEOUT);
815 	if (ret)
816 		dev_err(dev, "hwecc write timeout\n");
817 
818 timeout:
819 
820 	dma_unmap_single(nfc->dev, addr, len, DMA_TO_DEVICE);
821 	nfi_writel(nfc, 0, NFI_CON);
822 
823 	return ret;
824 }
825 
826 static int mtk_nfc_write_page(struct mtd_info *mtd, struct nand_chip *chip,
827 			      const u8 *buf, int page, int raw)
828 {
829 	struct mtk_nfc *nfc = nand_get_controller_data(chip);
830 	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
831 	size_t len;
832 	const u8 *bufpoi;
833 	u32 reg;
834 	int ret;
835 
836 	mtk_nfc_select_target(chip, chip->cur_cs);
837 	nand_prog_page_begin_op(chip, page, 0, NULL, 0);
838 
839 	if (!raw) {
840 		/* OOB => FDM: from register,  ECC: from HW */
841 		reg = nfi_readw(nfc, NFI_CNFG) | CNFG_AUTO_FMT_EN;
842 		nfi_writew(nfc, reg | CNFG_HW_ECC_EN, NFI_CNFG);
843 
844 		nfc->ecc_cfg.op = ECC_ENCODE;
845 		nfc->ecc_cfg.mode = ECC_NFI_MODE;
846 		ret = mtk_ecc_enable(nfc->ecc, &nfc->ecc_cfg);
847 		if (ret) {
848 			/* clear NFI config */
849 			reg = nfi_readw(nfc, NFI_CNFG);
850 			reg &= ~(CNFG_AUTO_FMT_EN | CNFG_HW_ECC_EN);
851 			nfi_writew(nfc, reg, NFI_CNFG);
852 
853 			return ret;
854 		}
855 
856 		memcpy(nfc->buffer, buf, mtd->writesize);
857 		mtk_nand->bad_mark.bm_swap(mtd, nfc->buffer, raw);
858 		bufpoi = nfc->buffer;
859 
860 		/* write OOB into the FDM registers (OOB area in MTK NAND) */
861 		mtk_nfc_write_fdm(chip);
862 	} else {
863 		bufpoi = buf;
864 	}
865 
866 	len = mtd->writesize + (raw ? mtd->oobsize : 0);
867 	ret = mtk_nfc_do_write_page(mtd, chip, bufpoi, page, len);
868 
869 	if (!raw)
870 		mtk_ecc_disable(nfc->ecc);
871 
872 	if (ret)
873 		return ret;
874 
875 	return nand_prog_page_end_op(chip);
876 }
877 
878 static int mtk_nfc_write_page_hwecc(struct nand_chip *chip, const u8 *buf,
879 				    int oob_on, int page)
880 {
881 	return mtk_nfc_write_page(nand_to_mtd(chip), chip, buf, page, 0);
882 }
883 
884 static int mtk_nfc_write_page_raw(struct nand_chip *chip, const u8 *buf,
885 				  int oob_on, int pg)
886 {
887 	struct mtd_info *mtd = nand_to_mtd(chip);
888 	struct mtk_nfc *nfc = nand_get_controller_data(chip);
889 
890 	mtk_nfc_format_page(mtd, buf);
891 	return mtk_nfc_write_page(mtd, chip, nfc->buffer, pg, 1);
892 }
893 
894 static int mtk_nfc_write_subpage_hwecc(struct nand_chip *chip, u32 offset,
895 				       u32 data_len, const u8 *buf,
896 				       int oob_on, int page)
897 {
898 	struct mtd_info *mtd = nand_to_mtd(chip);
899 	struct mtk_nfc *nfc = nand_get_controller_data(chip);
900 	int ret;
901 
902 	ret = mtk_nfc_format_subpage(mtd, offset, data_len, buf);
903 	if (ret < 0)
904 		return ret;
905 
906 	/* use the data in the private buffer (now with FDM and CRC) */
907 	return mtk_nfc_write_page(mtd, chip, nfc->buffer, page, 1);
908 }
909 
910 static int mtk_nfc_write_oob_std(struct nand_chip *chip, int page)
911 {
912 	return mtk_nfc_write_page_raw(chip, NULL, 1, page);
913 }
914 
915 static int mtk_nfc_update_ecc_stats(struct mtd_info *mtd, u8 *buf, u32 start,
916 				    u32 sectors)
917 {
918 	struct nand_chip *chip = mtd_to_nand(mtd);
919 	struct mtk_nfc *nfc = nand_get_controller_data(chip);
920 	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
921 	struct mtk_ecc_stats stats;
922 	u32 reg_size = mtk_nand->fdm.reg_size;
923 	int rc, i;
924 
925 	rc = nfi_readl(nfc, NFI_STA) & STA_EMP_PAGE;
926 	if (rc) {
927 		memset(buf, 0xff, sectors * chip->ecc.size);
928 		for (i = 0; i < sectors; i++)
929 			memset(oob_ptr(chip, start + i), 0xff, reg_size);
930 		return 0;
931 	}
932 
933 	mtk_ecc_get_stats(nfc->ecc, &stats, sectors);
934 	mtd->ecc_stats.corrected += stats.corrected;
935 	mtd->ecc_stats.failed += stats.failed;
936 
937 	return stats.bitflips;
938 }
939 
940 static int mtk_nfc_read_subpage(struct mtd_info *mtd, struct nand_chip *chip,
941 				u32 data_offs, u32 readlen,
942 				u8 *bufpoi, int page, int raw)
943 {
944 	struct mtk_nfc *nfc = nand_get_controller_data(chip);
945 	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
946 	u32 spare = mtk_nand->spare_per_sector;
947 	u32 column, sectors, start, end, reg;
948 	dma_addr_t addr;
949 	int bitflips = 0;
950 	size_t len;
951 	u8 *buf;
952 	int rc;
953 
954 	mtk_nfc_select_target(chip, chip->cur_cs);
955 	start = data_offs / chip->ecc.size;
956 	end = DIV_ROUND_UP(data_offs + readlen, chip->ecc.size);
957 
958 	sectors = end - start;
959 	column = start * (chip->ecc.size + spare);
960 
961 	len = sectors * chip->ecc.size + (raw ? sectors * spare : 0);
962 	buf = bufpoi + start * chip->ecc.size;
963 
964 	nand_read_page_op(chip, page, column, NULL, 0);
965 
966 	addr = dma_map_single(nfc->dev, buf, len, DMA_FROM_DEVICE);
967 	rc = dma_mapping_error(nfc->dev, addr);
968 	if (rc) {
969 		dev_err(nfc->dev, "dma mapping error\n");
970 
971 		return -EINVAL;
972 	}
973 
974 	reg = nfi_readw(nfc, NFI_CNFG);
975 	reg |= CNFG_READ_EN | CNFG_DMA_BURST_EN | CNFG_AHB;
976 	if (!raw) {
977 		reg |= CNFG_AUTO_FMT_EN | CNFG_HW_ECC_EN;
978 		nfi_writew(nfc, reg, NFI_CNFG);
979 
980 		nfc->ecc_cfg.mode = ECC_NFI_MODE;
981 		nfc->ecc_cfg.sectors = sectors;
982 		nfc->ecc_cfg.op = ECC_DECODE;
983 		rc = mtk_ecc_enable(nfc->ecc, &nfc->ecc_cfg);
984 		if (rc) {
985 			dev_err(nfc->dev, "ecc enable\n");
986 			/* clear NFI_CNFG */
987 			reg &= ~(CNFG_DMA_BURST_EN | CNFG_AHB | CNFG_READ_EN |
988 				CNFG_AUTO_FMT_EN | CNFG_HW_ECC_EN);
989 			nfi_writew(nfc, reg, NFI_CNFG);
990 			dma_unmap_single(nfc->dev, addr, len, DMA_FROM_DEVICE);
991 
992 			return rc;
993 		}
994 	} else {
995 		nfi_writew(nfc, reg, NFI_CNFG);
996 	}
997 
998 	nfi_writel(nfc, sectors << CON_SEC_SHIFT, NFI_CON);
999 	nfi_writew(nfc, INTR_AHB_DONE_EN, NFI_INTR_EN);
1000 	nfi_writel(nfc, lower_32_bits(addr), NFI_STRADDR);
1001 
1002 	init_completion(&nfc->done);
1003 	reg = nfi_readl(nfc, NFI_CON) | CON_BRD;
1004 	nfi_writel(nfc, reg, NFI_CON);
1005 	nfi_writew(nfc, STAR_EN, NFI_STRDATA);
1006 
1007 	rc = wait_for_completion_timeout(&nfc->done, msecs_to_jiffies(500));
1008 	if (!rc)
1009 		dev_warn(nfc->dev, "read ahb/dma done timeout\n");
1010 
1011 	rc = readl_poll_timeout_atomic(nfc->regs + NFI_BYTELEN, reg,
1012 				       ADDRCNTR_SEC(reg) >= sectors, 10,
1013 				       MTK_TIMEOUT);
1014 	if (rc < 0) {
1015 		dev_err(nfc->dev, "subpage done timeout\n");
1016 		bitflips = -EIO;
1017 	} else if (!raw) {
1018 		rc = mtk_ecc_wait_done(nfc->ecc, ECC_DECODE);
1019 		bitflips = rc < 0 ? -ETIMEDOUT :
1020 			mtk_nfc_update_ecc_stats(mtd, buf, start, sectors);
1021 		mtk_nfc_read_fdm(chip, start, sectors);
1022 	}
1023 
1024 	dma_unmap_single(nfc->dev, addr, len, DMA_FROM_DEVICE);
1025 
1026 	if (raw)
1027 		goto done;
1028 
1029 	mtk_ecc_disable(nfc->ecc);
1030 
1031 	if (clamp(mtk_nand->bad_mark.sec, start, end) == mtk_nand->bad_mark.sec)
1032 		mtk_nand->bad_mark.bm_swap(mtd, bufpoi, raw);
1033 done:
1034 	nfi_writel(nfc, 0, NFI_CON);
1035 
1036 	return bitflips;
1037 }
1038 
1039 static int mtk_nfc_read_subpage_hwecc(struct nand_chip *chip, u32 off,
1040 				      u32 len, u8 *p, int pg)
1041 {
1042 	return mtk_nfc_read_subpage(nand_to_mtd(chip), chip, off, len, p, pg,
1043 				    0);
1044 }
1045 
1046 static int mtk_nfc_read_page_hwecc(struct nand_chip *chip, u8 *p, int oob_on,
1047 				   int pg)
1048 {
1049 	struct mtd_info *mtd = nand_to_mtd(chip);
1050 
1051 	return mtk_nfc_read_subpage(mtd, chip, 0, mtd->writesize, p, pg, 0);
1052 }
1053 
1054 static int mtk_nfc_read_page_raw(struct nand_chip *chip, u8 *buf, int oob_on,
1055 				 int page)
1056 {
1057 	struct mtd_info *mtd = nand_to_mtd(chip);
1058 	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
1059 	struct mtk_nfc *nfc = nand_get_controller_data(chip);
1060 	struct mtk_nfc_fdm *fdm = &mtk_nand->fdm;
1061 	int i, ret;
1062 
1063 	memset(nfc->buffer, 0xff, mtd->writesize + mtd->oobsize);
1064 	ret = mtk_nfc_read_subpage(mtd, chip, 0, mtd->writesize, nfc->buffer,
1065 				   page, 1);
1066 	if (ret < 0)
1067 		return ret;
1068 
1069 	for (i = 0; i < chip->ecc.steps; i++) {
1070 		memcpy(oob_ptr(chip, i), mtk_oob_ptr(chip, i), fdm->reg_size);
1071 
1072 		if (i == mtk_nand->bad_mark.sec)
1073 			mtk_nand->bad_mark.bm_swap(mtd, nfc->buffer, 1);
1074 
1075 		if (buf)
1076 			memcpy(data_ptr(chip, buf, i), mtk_data_ptr(chip, i),
1077 			       chip->ecc.size);
1078 	}
1079 
1080 	return ret;
1081 }
1082 
1083 static int mtk_nfc_read_oob_std(struct nand_chip *chip, int page)
1084 {
1085 	return mtk_nfc_read_page_raw(chip, NULL, 1, page);
1086 }
1087 
1088 static inline void mtk_nfc_hw_init(struct mtk_nfc *nfc)
1089 {
1090 	/*
1091 	 * CNRNB: nand ready/busy register
1092 	 * -------------------------------
1093 	 * 7:4: timeout register for polling the NAND busy/ready signal
1094 	 * 0  : poll the status of the busy/ready signal after [7:4]*16 cycles.
1095 	 */
1096 	nfi_writew(nfc, 0xf1, NFI_CNRNB);
1097 	nfi_writel(nfc, PAGEFMT_8K_16K, NFI_PAGEFMT);
1098 
1099 	mtk_nfc_hw_reset(nfc);
1100 
1101 	nfi_readl(nfc, NFI_INTR_STA);
1102 	nfi_writel(nfc, 0, NFI_INTR_EN);
1103 }
1104 
1105 static irqreturn_t mtk_nfc_irq(int irq, void *id)
1106 {
1107 	struct mtk_nfc *nfc = id;
1108 	u16 sta, ien;
1109 
1110 	sta = nfi_readw(nfc, NFI_INTR_STA);
1111 	ien = nfi_readw(nfc, NFI_INTR_EN);
1112 
1113 	if (!(sta & ien))
1114 		return IRQ_NONE;
1115 
1116 	nfi_writew(nfc, ~sta & ien, NFI_INTR_EN);
1117 	complete(&nfc->done);
1118 
1119 	return IRQ_HANDLED;
1120 }
1121 
1122 static int mtk_nfc_enable_clk(struct device *dev, struct mtk_nfc_clk *clk)
1123 {
1124 	int ret;
1125 
1126 	ret = clk_prepare_enable(clk->nfi_clk);
1127 	if (ret) {
1128 		dev_err(dev, "failed to enable nfi clk\n");
1129 		return ret;
1130 	}
1131 
1132 	ret = clk_prepare_enable(clk->pad_clk);
1133 	if (ret) {
1134 		dev_err(dev, "failed to enable pad clk\n");
1135 		clk_disable_unprepare(clk->nfi_clk);
1136 		return ret;
1137 	}
1138 
1139 	return 0;
1140 }
1141 
1142 static void mtk_nfc_disable_clk(struct mtk_nfc_clk *clk)
1143 {
1144 	clk_disable_unprepare(clk->nfi_clk);
1145 	clk_disable_unprepare(clk->pad_clk);
1146 }
1147 
1148 static int mtk_nfc_ooblayout_free(struct mtd_info *mtd, int section,
1149 				  struct mtd_oob_region *oob_region)
1150 {
1151 	struct nand_chip *chip = mtd_to_nand(mtd);
1152 	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
1153 	struct mtk_nfc_fdm *fdm = &mtk_nand->fdm;
1154 	u32 eccsteps;
1155 
1156 	eccsteps = mtd->writesize / chip->ecc.size;
1157 
1158 	if (section >= eccsteps)
1159 		return -ERANGE;
1160 
1161 	oob_region->length = fdm->reg_size - fdm->ecc_size;
1162 	oob_region->offset = section * fdm->reg_size + fdm->ecc_size;
1163 
1164 	return 0;
1165 }
1166 
1167 static int mtk_nfc_ooblayout_ecc(struct mtd_info *mtd, int section,
1168 				 struct mtd_oob_region *oob_region)
1169 {
1170 	struct nand_chip *chip = mtd_to_nand(mtd);
1171 	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
1172 	u32 eccsteps;
1173 
1174 	if (section)
1175 		return -ERANGE;
1176 
1177 	eccsteps = mtd->writesize / chip->ecc.size;
1178 	oob_region->offset = mtk_nand->fdm.reg_size * eccsteps;
1179 	oob_region->length = mtd->oobsize - oob_region->offset;
1180 
1181 	return 0;
1182 }
1183 
1184 static const struct mtd_ooblayout_ops mtk_nfc_ooblayout_ops = {
1185 	.free = mtk_nfc_ooblayout_free,
1186 	.ecc = mtk_nfc_ooblayout_ecc,
1187 };
1188 
1189 static void mtk_nfc_set_fdm(struct mtk_nfc_fdm *fdm, struct mtd_info *mtd)
1190 {
1191 	struct nand_chip *nand = mtd_to_nand(mtd);
1192 	struct mtk_nfc_nand_chip *chip = to_mtk_nand(nand);
1193 	struct mtk_nfc *nfc = nand_get_controller_data(nand);
1194 	u32 ecc_bytes;
1195 
1196 	ecc_bytes = DIV_ROUND_UP(nand->ecc.strength *
1197 				 mtk_ecc_get_parity_bits(nfc->ecc), 8);
1198 
1199 	fdm->reg_size = chip->spare_per_sector - ecc_bytes;
1200 	if (fdm->reg_size > NFI_FDM_MAX_SIZE)
1201 		fdm->reg_size = NFI_FDM_MAX_SIZE;
1202 
1203 	/* bad block mark storage */
1204 	fdm->ecc_size = 1;
1205 }
1206 
1207 static void mtk_nfc_set_bad_mark_ctl(struct mtk_nfc_bad_mark_ctl *bm_ctl,
1208 				     struct mtd_info *mtd)
1209 {
1210 	struct nand_chip *nand = mtd_to_nand(mtd);
1211 
1212 	if (mtd->writesize == 512) {
1213 		bm_ctl->bm_swap = mtk_nfc_no_bad_mark_swap;
1214 	} else {
1215 		bm_ctl->bm_swap = mtk_nfc_bad_mark_swap;
1216 		bm_ctl->sec = mtd->writesize / mtk_data_len(nand);
1217 		bm_ctl->pos = mtd->writesize % mtk_data_len(nand);
1218 	}
1219 }
1220 
1221 static int mtk_nfc_set_spare_per_sector(u32 *sps, struct mtd_info *mtd)
1222 {
1223 	struct nand_chip *nand = mtd_to_nand(mtd);
1224 	struct mtk_nfc *nfc = nand_get_controller_data(nand);
1225 	const u8 *spare = nfc->caps->spare_size;
1226 	u32 eccsteps, i, closest_spare = 0;
1227 
1228 	eccsteps = mtd->writesize / nand->ecc.size;
1229 	*sps = mtd->oobsize / eccsteps;
1230 
1231 	if (nand->ecc.size == 1024)
1232 		*sps >>= 1;
1233 
1234 	if (*sps < MTK_NFC_MIN_SPARE)
1235 		return -EINVAL;
1236 
1237 	for (i = 0; i < nfc->caps->num_spare_size; i++) {
1238 		if (*sps >= spare[i] && spare[i] >= spare[closest_spare]) {
1239 			closest_spare = i;
1240 			if (*sps == spare[i])
1241 				break;
1242 		}
1243 	}
1244 
1245 	*sps = spare[closest_spare];
1246 
1247 	if (nand->ecc.size == 1024)
1248 		*sps <<= 1;
1249 
1250 	return 0;
1251 }
1252 
1253 static int mtk_nfc_ecc_init(struct device *dev, struct mtd_info *mtd)
1254 {
1255 	struct nand_chip *nand = mtd_to_nand(mtd);
1256 	const struct nand_ecc_props *requirements =
1257 		nanddev_get_ecc_requirements(&nand->base);
1258 	struct mtk_nfc *nfc = nand_get_controller_data(nand);
1259 	u32 spare;
1260 	int free, ret;
1261 
1262 	/* support only ecc hw mode */
1263 	if (nand->ecc.engine_type != NAND_ECC_ENGINE_TYPE_ON_HOST) {
1264 		dev_err(dev, "ecc.engine_type not supported\n");
1265 		return -EINVAL;
1266 	}
1267 
1268 	/* if optional dt settings not present */
1269 	if (!nand->ecc.size || !nand->ecc.strength) {
1270 		/* use datasheet requirements */
1271 		nand->ecc.strength = requirements->strength;
1272 		nand->ecc.size = requirements->step_size;
1273 
1274 		/*
1275 		 * align eccstrength and eccsize
1276 		 * this controller only supports 512 and 1024 sizes
1277 		 */
1278 		if (nand->ecc.size < 1024) {
1279 			if (mtd->writesize > 512 &&
1280 			    nfc->caps->max_sector_size > 512) {
1281 				nand->ecc.size = 1024;
1282 				nand->ecc.strength <<= 1;
1283 			} else {
1284 				nand->ecc.size = 512;
1285 			}
1286 		} else {
1287 			nand->ecc.size = 1024;
1288 		}
1289 
1290 		ret = mtk_nfc_set_spare_per_sector(&spare, mtd);
1291 		if (ret)
1292 			return ret;
1293 
1294 		/* calculate oob bytes except ecc parity data */
1295 		free = (nand->ecc.strength * mtk_ecc_get_parity_bits(nfc->ecc)
1296 			+ 7) >> 3;
1297 		free = spare - free;
1298 
1299 		/*
1300 		 * enhance ecc strength if oob left is bigger than max FDM size
1301 		 * or reduce ecc strength if oob size is not enough for ecc
1302 		 * parity data.
1303 		 */
1304 		if (free > NFI_FDM_MAX_SIZE) {
1305 			spare -= NFI_FDM_MAX_SIZE;
1306 			nand->ecc.strength = (spare << 3) /
1307 					     mtk_ecc_get_parity_bits(nfc->ecc);
1308 		} else if (free < 0) {
1309 			spare -= NFI_FDM_MIN_SIZE;
1310 			nand->ecc.strength = (spare << 3) /
1311 					     mtk_ecc_get_parity_bits(nfc->ecc);
1312 		}
1313 	}
1314 
1315 	mtk_ecc_adjust_strength(nfc->ecc, &nand->ecc.strength);
1316 
1317 	dev_info(dev, "eccsize %d eccstrength %d\n",
1318 		 nand->ecc.size, nand->ecc.strength);
1319 
1320 	return 0;
1321 }
1322 
1323 static int mtk_nfc_attach_chip(struct nand_chip *chip)
1324 {
1325 	struct mtd_info *mtd = nand_to_mtd(chip);
1326 	struct device *dev = mtd->dev.parent;
1327 	struct mtk_nfc *nfc = nand_get_controller_data(chip);
1328 	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
1329 	int len;
1330 	int ret;
1331 
1332 	if (chip->options & NAND_BUSWIDTH_16) {
1333 		dev_err(dev, "16bits buswidth not supported");
1334 		return -EINVAL;
1335 	}
1336 
1337 	/* store bbt magic in page, cause OOB is not protected */
1338 	if (chip->bbt_options & NAND_BBT_USE_FLASH)
1339 		chip->bbt_options |= NAND_BBT_NO_OOB;
1340 
1341 	ret = mtk_nfc_ecc_init(dev, mtd);
1342 	if (ret)
1343 		return ret;
1344 
1345 	ret = mtk_nfc_set_spare_per_sector(&mtk_nand->spare_per_sector, mtd);
1346 	if (ret)
1347 		return ret;
1348 
1349 	mtk_nfc_set_fdm(&mtk_nand->fdm, mtd);
1350 	mtk_nfc_set_bad_mark_ctl(&mtk_nand->bad_mark, mtd);
1351 
1352 	len = mtd->writesize + mtd->oobsize;
1353 	nfc->buffer = devm_kzalloc(dev, len, GFP_KERNEL);
1354 	if (!nfc->buffer)
1355 		return  -ENOMEM;
1356 
1357 	return 0;
1358 }
1359 
1360 static const struct nand_controller_ops mtk_nfc_controller_ops = {
1361 	.attach_chip = mtk_nfc_attach_chip,
1362 	.setup_interface = mtk_nfc_setup_interface,
1363 	.exec_op = mtk_nfc_exec_op,
1364 };
1365 
1366 static int mtk_nfc_nand_chip_init(struct device *dev, struct mtk_nfc *nfc,
1367 				  struct device_node *np)
1368 {
1369 	struct mtk_nfc_nand_chip *chip;
1370 	struct nand_chip *nand;
1371 	struct mtd_info *mtd;
1372 	int nsels;
1373 	u32 tmp;
1374 	int ret;
1375 	int i;
1376 
1377 	if (!of_get_property(np, "reg", &nsels))
1378 		return -ENODEV;
1379 
1380 	nsels /= sizeof(u32);
1381 	if (!nsels || nsels > MTK_NAND_MAX_NSELS) {
1382 		dev_err(dev, "invalid reg property size %d\n", nsels);
1383 		return -EINVAL;
1384 	}
1385 
1386 	chip = devm_kzalloc(dev, sizeof(*chip) + nsels * sizeof(u8),
1387 			    GFP_KERNEL);
1388 	if (!chip)
1389 		return -ENOMEM;
1390 
1391 	chip->nsels = nsels;
1392 	for (i = 0; i < nsels; i++) {
1393 		ret = of_property_read_u32_index(np, "reg", i, &tmp);
1394 		if (ret) {
1395 			dev_err(dev, "reg property failure : %d\n", ret);
1396 			return ret;
1397 		}
1398 
1399 		if (tmp >= MTK_NAND_MAX_NSELS) {
1400 			dev_err(dev, "invalid CS: %u\n", tmp);
1401 			return -EINVAL;
1402 		}
1403 
1404 		if (test_and_set_bit(tmp, &nfc->assigned_cs)) {
1405 			dev_err(dev, "CS %u already assigned\n", tmp);
1406 			return -EINVAL;
1407 		}
1408 
1409 		chip->sels[i] = tmp;
1410 	}
1411 
1412 	nand = &chip->nand;
1413 	nand->controller = &nfc->controller;
1414 
1415 	nand_set_flash_node(nand, np);
1416 	nand_set_controller_data(nand, nfc);
1417 
1418 	nand->options |= NAND_USES_DMA | NAND_SUBPAGE_READ;
1419 
1420 	/* set default mode in case dt entry is missing */
1421 	nand->ecc.engine_type = NAND_ECC_ENGINE_TYPE_ON_HOST;
1422 
1423 	nand->ecc.write_subpage = mtk_nfc_write_subpage_hwecc;
1424 	nand->ecc.write_page_raw = mtk_nfc_write_page_raw;
1425 	nand->ecc.write_page = mtk_nfc_write_page_hwecc;
1426 	nand->ecc.write_oob_raw = mtk_nfc_write_oob_std;
1427 	nand->ecc.write_oob = mtk_nfc_write_oob_std;
1428 
1429 	nand->ecc.read_subpage = mtk_nfc_read_subpage_hwecc;
1430 	nand->ecc.read_page_raw = mtk_nfc_read_page_raw;
1431 	nand->ecc.read_page = mtk_nfc_read_page_hwecc;
1432 	nand->ecc.read_oob_raw = mtk_nfc_read_oob_std;
1433 	nand->ecc.read_oob = mtk_nfc_read_oob_std;
1434 
1435 	mtd = nand_to_mtd(nand);
1436 	mtd->owner = THIS_MODULE;
1437 	mtd->dev.parent = dev;
1438 	mtd->name = MTK_NAME;
1439 	mtd_set_ooblayout(mtd, &mtk_nfc_ooblayout_ops);
1440 
1441 	mtk_nfc_hw_init(nfc);
1442 
1443 	ret = nand_scan(nand, nsels);
1444 	if (ret)
1445 		return ret;
1446 
1447 	ret = mtd_device_register(mtd, NULL, 0);
1448 	if (ret) {
1449 		dev_err(dev, "mtd parse partition error\n");
1450 		nand_cleanup(nand);
1451 		return ret;
1452 	}
1453 
1454 	list_add_tail(&chip->node, &nfc->chips);
1455 
1456 	return 0;
1457 }
1458 
1459 static int mtk_nfc_nand_chips_init(struct device *dev, struct mtk_nfc *nfc)
1460 {
1461 	struct device_node *np = dev->of_node;
1462 	struct device_node *nand_np;
1463 	int ret;
1464 
1465 	for_each_child_of_node(np, nand_np) {
1466 		ret = mtk_nfc_nand_chip_init(dev, nfc, nand_np);
1467 		if (ret) {
1468 			of_node_put(nand_np);
1469 			return ret;
1470 		}
1471 	}
1472 
1473 	return 0;
1474 }
1475 
1476 static const struct mtk_nfc_caps mtk_nfc_caps_mt2701 = {
1477 	.spare_size = spare_size_mt2701,
1478 	.num_spare_size = 16,
1479 	.pageformat_spare_shift = 4,
1480 	.nfi_clk_div = 1,
1481 	.max_sector = 16,
1482 	.max_sector_size = 1024,
1483 };
1484 
1485 static const struct mtk_nfc_caps mtk_nfc_caps_mt2712 = {
1486 	.spare_size = spare_size_mt2712,
1487 	.num_spare_size = 19,
1488 	.pageformat_spare_shift = 16,
1489 	.nfi_clk_div = 2,
1490 	.max_sector = 16,
1491 	.max_sector_size = 1024,
1492 };
1493 
1494 static const struct mtk_nfc_caps mtk_nfc_caps_mt7622 = {
1495 	.spare_size = spare_size_mt7622,
1496 	.num_spare_size = 4,
1497 	.pageformat_spare_shift = 4,
1498 	.nfi_clk_div = 1,
1499 	.max_sector = 8,
1500 	.max_sector_size = 512,
1501 };
1502 
1503 static const struct of_device_id mtk_nfc_id_table[] = {
1504 	{
1505 		.compatible = "mediatek,mt2701-nfc",
1506 		.data = &mtk_nfc_caps_mt2701,
1507 	}, {
1508 		.compatible = "mediatek,mt2712-nfc",
1509 		.data = &mtk_nfc_caps_mt2712,
1510 	}, {
1511 		.compatible = "mediatek,mt7622-nfc",
1512 		.data = &mtk_nfc_caps_mt7622,
1513 	},
1514 	{}
1515 };
1516 MODULE_DEVICE_TABLE(of, mtk_nfc_id_table);
1517 
1518 static int mtk_nfc_probe(struct platform_device *pdev)
1519 {
1520 	struct device *dev = &pdev->dev;
1521 	struct device_node *np = dev->of_node;
1522 	struct mtk_nfc *nfc;
1523 	struct resource *res;
1524 	int ret, irq;
1525 
1526 	nfc = devm_kzalloc(dev, sizeof(*nfc), GFP_KERNEL);
1527 	if (!nfc)
1528 		return -ENOMEM;
1529 
1530 	nand_controller_init(&nfc->controller);
1531 	INIT_LIST_HEAD(&nfc->chips);
1532 	nfc->controller.ops = &mtk_nfc_controller_ops;
1533 
1534 	/* probe defer if not ready */
1535 	nfc->ecc = of_mtk_ecc_get(np);
1536 	if (IS_ERR(nfc->ecc))
1537 		return PTR_ERR(nfc->ecc);
1538 	else if (!nfc->ecc)
1539 		return -ENODEV;
1540 
1541 	nfc->caps = of_device_get_match_data(dev);
1542 	nfc->dev = dev;
1543 
1544 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1545 	nfc->regs = devm_ioremap_resource(dev, res);
1546 	if (IS_ERR(nfc->regs)) {
1547 		ret = PTR_ERR(nfc->regs);
1548 		goto release_ecc;
1549 	}
1550 
1551 	nfc->clk.nfi_clk = devm_clk_get(dev, "nfi_clk");
1552 	if (IS_ERR(nfc->clk.nfi_clk)) {
1553 		dev_err(dev, "no clk\n");
1554 		ret = PTR_ERR(nfc->clk.nfi_clk);
1555 		goto release_ecc;
1556 	}
1557 
1558 	nfc->clk.pad_clk = devm_clk_get(dev, "pad_clk");
1559 	if (IS_ERR(nfc->clk.pad_clk)) {
1560 		dev_err(dev, "no pad clk\n");
1561 		ret = PTR_ERR(nfc->clk.pad_clk);
1562 		goto release_ecc;
1563 	}
1564 
1565 	ret = mtk_nfc_enable_clk(dev, &nfc->clk);
1566 	if (ret)
1567 		goto release_ecc;
1568 
1569 	irq = platform_get_irq(pdev, 0);
1570 	if (irq < 0) {
1571 		ret = -EINVAL;
1572 		goto clk_disable;
1573 	}
1574 
1575 	ret = devm_request_irq(dev, irq, mtk_nfc_irq, 0x0, "mtk-nand", nfc);
1576 	if (ret) {
1577 		dev_err(dev, "failed to request nfi irq\n");
1578 		goto clk_disable;
1579 	}
1580 
1581 	ret = dma_set_mask(dev, DMA_BIT_MASK(32));
1582 	if (ret) {
1583 		dev_err(dev, "failed to set dma mask\n");
1584 		goto clk_disable;
1585 	}
1586 
1587 	platform_set_drvdata(pdev, nfc);
1588 
1589 	ret = mtk_nfc_nand_chips_init(dev, nfc);
1590 	if (ret) {
1591 		dev_err(dev, "failed to init nand chips\n");
1592 		goto clk_disable;
1593 	}
1594 
1595 	return 0;
1596 
1597 clk_disable:
1598 	mtk_nfc_disable_clk(&nfc->clk);
1599 
1600 release_ecc:
1601 	mtk_ecc_release(nfc->ecc);
1602 
1603 	return ret;
1604 }
1605 
1606 static int mtk_nfc_remove(struct platform_device *pdev)
1607 {
1608 	struct mtk_nfc *nfc = platform_get_drvdata(pdev);
1609 	struct mtk_nfc_nand_chip *mtk_chip;
1610 	struct nand_chip *chip;
1611 	int ret;
1612 
1613 	while (!list_empty(&nfc->chips)) {
1614 		mtk_chip = list_first_entry(&nfc->chips,
1615 					    struct mtk_nfc_nand_chip, node);
1616 		chip = &mtk_chip->nand;
1617 		ret = mtd_device_unregister(nand_to_mtd(chip));
1618 		WARN_ON(ret);
1619 		nand_cleanup(chip);
1620 		list_del(&mtk_chip->node);
1621 	}
1622 
1623 	mtk_ecc_release(nfc->ecc);
1624 	mtk_nfc_disable_clk(&nfc->clk);
1625 
1626 	return 0;
1627 }
1628 
1629 #ifdef CONFIG_PM_SLEEP
1630 static int mtk_nfc_suspend(struct device *dev)
1631 {
1632 	struct mtk_nfc *nfc = dev_get_drvdata(dev);
1633 
1634 	mtk_nfc_disable_clk(&nfc->clk);
1635 
1636 	return 0;
1637 }
1638 
1639 static int mtk_nfc_resume(struct device *dev)
1640 {
1641 	struct mtk_nfc *nfc = dev_get_drvdata(dev);
1642 	struct mtk_nfc_nand_chip *chip;
1643 	struct nand_chip *nand;
1644 	int ret;
1645 	u32 i;
1646 
1647 	udelay(200);
1648 
1649 	ret = mtk_nfc_enable_clk(dev, &nfc->clk);
1650 	if (ret)
1651 		return ret;
1652 
1653 	/* reset NAND chip if VCC was powered off */
1654 	list_for_each_entry(chip, &nfc->chips, node) {
1655 		nand = &chip->nand;
1656 		for (i = 0; i < chip->nsels; i++)
1657 			nand_reset(nand, i);
1658 	}
1659 
1660 	return 0;
1661 }
1662 
1663 static SIMPLE_DEV_PM_OPS(mtk_nfc_pm_ops, mtk_nfc_suspend, mtk_nfc_resume);
1664 #endif
1665 
1666 static struct platform_driver mtk_nfc_driver = {
1667 	.probe  = mtk_nfc_probe,
1668 	.remove = mtk_nfc_remove,
1669 	.driver = {
1670 		.name  = MTK_NAME,
1671 		.of_match_table = mtk_nfc_id_table,
1672 #ifdef CONFIG_PM_SLEEP
1673 		.pm = &mtk_nfc_pm_ops,
1674 #endif
1675 	},
1676 };
1677 
1678 module_platform_driver(mtk_nfc_driver);
1679 
1680 MODULE_LICENSE("Dual MIT/GPL");
1681 MODULE_AUTHOR("Xiaolei Li <xiaolei.li@mediatek.com>");
1682 MODULE_DESCRIPTION("MTK Nand Flash Controller Driver");
1683