xref: /openbmc/linux/drivers/mtd/nand/raw/fsmc_nand.c (revision 242cdad8)
1 /*
2  * ST Microelectronics
3  * Flexible Static Memory Controller (FSMC)
4  * Driver for NAND portions
5  *
6  * Copyright © 2010 ST Microelectronics
7  * Vipin Kumar <vipin.kumar@st.com>
8  * Ashish Priyadarshi
9  *
10  * Based on drivers/mtd/nand/nomadik_nand.c (removed in v3.8)
11  *  Copyright © 2007 STMicroelectronics Pvt. Ltd.
12  *  Copyright © 2009 Alessandro Rubini
13  *
14  * This file is licensed under the terms of the GNU General Public
15  * License version 2. This program is licensed "as is" without any
16  * warranty of any kind, whether express or implied.
17  */
18 
19 #include <linux/clk.h>
20 #include <linux/completion.h>
21 #include <linux/dmaengine.h>
22 #include <linux/dma-direction.h>
23 #include <linux/dma-mapping.h>
24 #include <linux/err.h>
25 #include <linux/init.h>
26 #include <linux/module.h>
27 #include <linux/resource.h>
28 #include <linux/sched.h>
29 #include <linux/types.h>
30 #include <linux/mtd/mtd.h>
31 #include <linux/mtd/rawnand.h>
32 #include <linux/mtd/nand_ecc.h>
33 #include <linux/platform_device.h>
34 #include <linux/of.h>
35 #include <linux/mtd/partitions.h>
36 #include <linux/io.h>
37 #include <linux/slab.h>
38 #include <linux/amba/bus.h>
39 #include <mtd/mtd-abi.h>
40 
41 /* fsmc controller registers for NOR flash */
42 #define CTRL			0x0
43 	/* ctrl register definitions */
44 	#define BANK_ENABLE		(1 << 0)
45 	#define MUXED			(1 << 1)
46 	#define NOR_DEV			(2 << 2)
47 	#define WIDTH_8			(0 << 4)
48 	#define WIDTH_16		(1 << 4)
49 	#define RSTPWRDWN		(1 << 6)
50 	#define WPROT			(1 << 7)
51 	#define WRT_ENABLE		(1 << 12)
52 	#define WAIT_ENB		(1 << 13)
53 
54 #define CTRL_TIM		0x4
55 	/* ctrl_tim register definitions */
56 
57 #define FSMC_NOR_BANK_SZ	0x8
58 #define FSMC_NOR_REG_SIZE	0x40
59 
60 #define FSMC_NOR_REG(base, bank, reg)		(base + \
61 						FSMC_NOR_BANK_SZ * (bank) + \
62 						reg)
63 
64 /* fsmc controller registers for NAND flash */
65 #define FSMC_PC			0x00
66 	/* pc register definitions */
67 	#define FSMC_RESET		(1 << 0)
68 	#define FSMC_WAITON		(1 << 1)
69 	#define FSMC_ENABLE		(1 << 2)
70 	#define FSMC_DEVTYPE_NAND	(1 << 3)
71 	#define FSMC_DEVWID_8		(0 << 4)
72 	#define FSMC_DEVWID_16		(1 << 4)
73 	#define FSMC_ECCEN		(1 << 6)
74 	#define FSMC_ECCPLEN_512	(0 << 7)
75 	#define FSMC_ECCPLEN_256	(1 << 7)
76 	#define FSMC_TCLR_1		(1)
77 	#define FSMC_TCLR_SHIFT		(9)
78 	#define FSMC_TCLR_MASK		(0xF)
79 	#define FSMC_TAR_1		(1)
80 	#define FSMC_TAR_SHIFT		(13)
81 	#define FSMC_TAR_MASK		(0xF)
82 #define STS			0x04
83 	/* sts register definitions */
84 	#define FSMC_CODE_RDY		(1 << 15)
85 #define COMM			0x08
86 	/* comm register definitions */
87 	#define FSMC_TSET_0		0
88 	#define FSMC_TSET_SHIFT		0
89 	#define FSMC_TSET_MASK		0xFF
90 	#define FSMC_TWAIT_6		6
91 	#define FSMC_TWAIT_SHIFT	8
92 	#define FSMC_TWAIT_MASK		0xFF
93 	#define FSMC_THOLD_4		4
94 	#define FSMC_THOLD_SHIFT	16
95 	#define FSMC_THOLD_MASK		0xFF
96 	#define FSMC_THIZ_1		1
97 	#define FSMC_THIZ_SHIFT		24
98 	#define FSMC_THIZ_MASK		0xFF
99 #define ATTRIB			0x0C
100 #define IOATA			0x10
101 #define ECC1			0x14
102 #define ECC2			0x18
103 #define ECC3			0x1C
104 #define FSMC_NAND_BANK_SZ	0x20
105 
106 #define FSMC_BUSY_WAIT_TIMEOUT	(1 * HZ)
107 
108 struct fsmc_nand_timings {
109 	uint8_t tclr;
110 	uint8_t tar;
111 	uint8_t thiz;
112 	uint8_t thold;
113 	uint8_t twait;
114 	uint8_t tset;
115 };
116 
117 enum access_mode {
118 	USE_DMA_ACCESS = 1,
119 	USE_WORD_ACCESS,
120 };
121 
122 /**
123  * struct fsmc_nand_data - structure for FSMC NAND device state
124  *
125  * @pid:		Part ID on the AMBA PrimeCell format
126  * @mtd:		MTD info for a NAND flash.
127  * @nand:		Chip related info for a NAND flash.
128  * @partitions:		Partition info for a NAND Flash.
129  * @nr_partitions:	Total number of partition of a NAND flash.
130  *
131  * @bank:		Bank number for probed device.
132  * @clk:		Clock structure for FSMC.
133  *
134  * @read_dma_chan:	DMA channel for read access
135  * @write_dma_chan:	DMA channel for write access to NAND
136  * @dma_access_complete: Completion structure
137  *
138  * @data_pa:		NAND Physical port for Data.
139  * @data_va:		NAND port for Data.
140  * @cmd_va:		NAND port for Command.
141  * @addr_va:		NAND port for Address.
142  * @regs_va:		Registers base address for a given bank.
143  */
144 struct fsmc_nand_data {
145 	u32			pid;
146 	struct nand_chip	nand;
147 
148 	unsigned int		bank;
149 	struct device		*dev;
150 	enum access_mode	mode;
151 	struct clk		*clk;
152 
153 	/* DMA related objects */
154 	struct dma_chan		*read_dma_chan;
155 	struct dma_chan		*write_dma_chan;
156 	struct completion	dma_access_complete;
157 
158 	struct fsmc_nand_timings *dev_timings;
159 
160 	dma_addr_t		data_pa;
161 	void __iomem		*data_va;
162 	void __iomem		*cmd_va;
163 	void __iomem		*addr_va;
164 	void __iomem		*regs_va;
165 };
166 
167 static int fsmc_ecc1_ooblayout_ecc(struct mtd_info *mtd, int section,
168 				   struct mtd_oob_region *oobregion)
169 {
170 	struct nand_chip *chip = mtd_to_nand(mtd);
171 
172 	if (section >= chip->ecc.steps)
173 		return -ERANGE;
174 
175 	oobregion->offset = (section * 16) + 2;
176 	oobregion->length = 3;
177 
178 	return 0;
179 }
180 
181 static int fsmc_ecc1_ooblayout_free(struct mtd_info *mtd, int section,
182 				    struct mtd_oob_region *oobregion)
183 {
184 	struct nand_chip *chip = mtd_to_nand(mtd);
185 
186 	if (section >= chip->ecc.steps)
187 		return -ERANGE;
188 
189 	oobregion->offset = (section * 16) + 8;
190 
191 	if (section < chip->ecc.steps - 1)
192 		oobregion->length = 8;
193 	else
194 		oobregion->length = mtd->oobsize - oobregion->offset;
195 
196 	return 0;
197 }
198 
199 static const struct mtd_ooblayout_ops fsmc_ecc1_ooblayout_ops = {
200 	.ecc = fsmc_ecc1_ooblayout_ecc,
201 	.free = fsmc_ecc1_ooblayout_free,
202 };
203 
204 /*
205  * ECC placement definitions in oobfree type format.
206  * There are 13 bytes of ecc for every 512 byte block and it has to be read
207  * consecutively and immediately after the 512 byte data block for hardware to
208  * generate the error bit offsets in 512 byte data.
209  */
210 static int fsmc_ecc4_ooblayout_ecc(struct mtd_info *mtd, int section,
211 				   struct mtd_oob_region *oobregion)
212 {
213 	struct nand_chip *chip = mtd_to_nand(mtd);
214 
215 	if (section >= chip->ecc.steps)
216 		return -ERANGE;
217 
218 	oobregion->length = chip->ecc.bytes;
219 
220 	if (!section && mtd->writesize <= 512)
221 		oobregion->offset = 0;
222 	else
223 		oobregion->offset = (section * 16) + 2;
224 
225 	return 0;
226 }
227 
228 static int fsmc_ecc4_ooblayout_free(struct mtd_info *mtd, int section,
229 				    struct mtd_oob_region *oobregion)
230 {
231 	struct nand_chip *chip = mtd_to_nand(mtd);
232 
233 	if (section >= chip->ecc.steps)
234 		return -ERANGE;
235 
236 	oobregion->offset = (section * 16) + 15;
237 
238 	if (section < chip->ecc.steps - 1)
239 		oobregion->length = 3;
240 	else
241 		oobregion->length = mtd->oobsize - oobregion->offset;
242 
243 	return 0;
244 }
245 
246 static const struct mtd_ooblayout_ops fsmc_ecc4_ooblayout_ops = {
247 	.ecc = fsmc_ecc4_ooblayout_ecc,
248 	.free = fsmc_ecc4_ooblayout_free,
249 };
250 
251 static inline struct fsmc_nand_data *mtd_to_fsmc(struct mtd_info *mtd)
252 {
253 	return container_of(mtd_to_nand(mtd), struct fsmc_nand_data, nand);
254 }
255 
256 /*
257  * fsmc_nand_setup - FSMC (Flexible Static Memory Controller) init routine
258  *
259  * This routine initializes timing parameters related to NAND memory access in
260  * FSMC registers
261  */
262 static void fsmc_nand_setup(struct fsmc_nand_data *host,
263 			    struct fsmc_nand_timings *tims)
264 {
265 	uint32_t value = FSMC_DEVTYPE_NAND | FSMC_ENABLE | FSMC_WAITON;
266 	uint32_t tclr, tar, thiz, thold, twait, tset;
267 
268 	tclr = (tims->tclr & FSMC_TCLR_MASK) << FSMC_TCLR_SHIFT;
269 	tar = (tims->tar & FSMC_TAR_MASK) << FSMC_TAR_SHIFT;
270 	thiz = (tims->thiz & FSMC_THIZ_MASK) << FSMC_THIZ_SHIFT;
271 	thold = (tims->thold & FSMC_THOLD_MASK) << FSMC_THOLD_SHIFT;
272 	twait = (tims->twait & FSMC_TWAIT_MASK) << FSMC_TWAIT_SHIFT;
273 	tset = (tims->tset & FSMC_TSET_MASK) << FSMC_TSET_SHIFT;
274 
275 	if (host->nand.options & NAND_BUSWIDTH_16)
276 		writel_relaxed(value | FSMC_DEVWID_16,
277 			       host->regs_va + FSMC_PC);
278 	else
279 		writel_relaxed(value | FSMC_DEVWID_8, host->regs_va + FSMC_PC);
280 
281 	writel_relaxed(readl(host->regs_va + FSMC_PC) | tclr | tar,
282 		       host->regs_va + FSMC_PC);
283 	writel_relaxed(thiz | thold | twait | tset, host->regs_va + COMM);
284 	writel_relaxed(thiz | thold | twait | tset, host->regs_va + ATTRIB);
285 }
286 
287 static int fsmc_calc_timings(struct fsmc_nand_data *host,
288 			     const struct nand_sdr_timings *sdrt,
289 			     struct fsmc_nand_timings *tims)
290 {
291 	unsigned long hclk = clk_get_rate(host->clk);
292 	unsigned long hclkn = NSEC_PER_SEC / hclk;
293 	uint32_t thiz, thold, twait, tset;
294 
295 	if (sdrt->tRC_min < 30000)
296 		return -EOPNOTSUPP;
297 
298 	tims->tar = DIV_ROUND_UP(sdrt->tAR_min / 1000, hclkn) - 1;
299 	if (tims->tar > FSMC_TAR_MASK)
300 		tims->tar = FSMC_TAR_MASK;
301 	tims->tclr = DIV_ROUND_UP(sdrt->tCLR_min / 1000, hclkn) - 1;
302 	if (tims->tclr > FSMC_TCLR_MASK)
303 		tims->tclr = FSMC_TCLR_MASK;
304 
305 	thiz = sdrt->tCS_min - sdrt->tWP_min;
306 	tims->thiz = DIV_ROUND_UP(thiz / 1000, hclkn);
307 
308 	thold = sdrt->tDH_min;
309 	if (thold < sdrt->tCH_min)
310 		thold = sdrt->tCH_min;
311 	if (thold < sdrt->tCLH_min)
312 		thold = sdrt->tCLH_min;
313 	if (thold < sdrt->tWH_min)
314 		thold = sdrt->tWH_min;
315 	if (thold < sdrt->tALH_min)
316 		thold = sdrt->tALH_min;
317 	if (thold < sdrt->tREH_min)
318 		thold = sdrt->tREH_min;
319 	tims->thold = DIV_ROUND_UP(thold / 1000, hclkn);
320 	if (tims->thold == 0)
321 		tims->thold = 1;
322 	else if (tims->thold > FSMC_THOLD_MASK)
323 		tims->thold = FSMC_THOLD_MASK;
324 
325 	twait = max(sdrt->tRP_min, sdrt->tWP_min);
326 	tims->twait = DIV_ROUND_UP(twait / 1000, hclkn) - 1;
327 	if (tims->twait == 0)
328 		tims->twait = 1;
329 	else if (tims->twait > FSMC_TWAIT_MASK)
330 		tims->twait = FSMC_TWAIT_MASK;
331 
332 	tset = max(sdrt->tCS_min - sdrt->tWP_min,
333 		   sdrt->tCEA_max - sdrt->tREA_max);
334 	tims->tset = DIV_ROUND_UP(tset / 1000, hclkn) - 1;
335 	if (tims->tset == 0)
336 		tims->tset = 1;
337 	else if (tims->tset > FSMC_TSET_MASK)
338 		tims->tset = FSMC_TSET_MASK;
339 
340 	return 0;
341 }
342 
343 static int fsmc_setup_data_interface(struct mtd_info *mtd, int csline,
344 				     const struct nand_data_interface *conf)
345 {
346 	struct nand_chip *nand = mtd_to_nand(mtd);
347 	struct fsmc_nand_data *host = nand_get_controller_data(nand);
348 	struct fsmc_nand_timings tims;
349 	const struct nand_sdr_timings *sdrt;
350 	int ret;
351 
352 	sdrt = nand_get_sdr_timings(conf);
353 	if (IS_ERR(sdrt))
354 		return PTR_ERR(sdrt);
355 
356 	ret = fsmc_calc_timings(host, sdrt, &tims);
357 	if (ret)
358 		return ret;
359 
360 	if (csline == NAND_DATA_IFACE_CHECK_ONLY)
361 		return 0;
362 
363 	fsmc_nand_setup(host, &tims);
364 
365 	return 0;
366 }
367 
368 /*
369  * fsmc_enable_hwecc - Enables Hardware ECC through FSMC registers
370  */
371 static void fsmc_enable_hwecc(struct mtd_info *mtd, int mode)
372 {
373 	struct fsmc_nand_data *host = mtd_to_fsmc(mtd);
374 
375 	writel_relaxed(readl(host->regs_va + FSMC_PC) & ~FSMC_ECCPLEN_256,
376 		       host->regs_va + FSMC_PC);
377 	writel_relaxed(readl(host->regs_va + FSMC_PC) & ~FSMC_ECCEN,
378 		       host->regs_va + FSMC_PC);
379 	writel_relaxed(readl(host->regs_va + FSMC_PC) | FSMC_ECCEN,
380 		       host->regs_va + FSMC_PC);
381 }
382 
383 /*
384  * fsmc_read_hwecc_ecc4 - Hardware ECC calculator for ecc4 option supported by
385  * FSMC. ECC is 13 bytes for 512 bytes of data (supports error correction up to
386  * max of 8-bits)
387  */
388 static int fsmc_read_hwecc_ecc4(struct mtd_info *mtd, const uint8_t *data,
389 				uint8_t *ecc)
390 {
391 	struct fsmc_nand_data *host = mtd_to_fsmc(mtd);
392 	uint32_t ecc_tmp;
393 	unsigned long deadline = jiffies + FSMC_BUSY_WAIT_TIMEOUT;
394 
395 	do {
396 		if (readl_relaxed(host->regs_va + STS) & FSMC_CODE_RDY)
397 			break;
398 		else
399 			cond_resched();
400 	} while (!time_after_eq(jiffies, deadline));
401 
402 	if (time_after_eq(jiffies, deadline)) {
403 		dev_err(host->dev, "calculate ecc timed out\n");
404 		return -ETIMEDOUT;
405 	}
406 
407 	ecc_tmp = readl_relaxed(host->regs_va + ECC1);
408 	ecc[0] = (uint8_t) (ecc_tmp >> 0);
409 	ecc[1] = (uint8_t) (ecc_tmp >> 8);
410 	ecc[2] = (uint8_t) (ecc_tmp >> 16);
411 	ecc[3] = (uint8_t) (ecc_tmp >> 24);
412 
413 	ecc_tmp = readl_relaxed(host->regs_va + ECC2);
414 	ecc[4] = (uint8_t) (ecc_tmp >> 0);
415 	ecc[5] = (uint8_t) (ecc_tmp >> 8);
416 	ecc[6] = (uint8_t) (ecc_tmp >> 16);
417 	ecc[7] = (uint8_t) (ecc_tmp >> 24);
418 
419 	ecc_tmp = readl_relaxed(host->regs_va + ECC3);
420 	ecc[8] = (uint8_t) (ecc_tmp >> 0);
421 	ecc[9] = (uint8_t) (ecc_tmp >> 8);
422 	ecc[10] = (uint8_t) (ecc_tmp >> 16);
423 	ecc[11] = (uint8_t) (ecc_tmp >> 24);
424 
425 	ecc_tmp = readl_relaxed(host->regs_va + STS);
426 	ecc[12] = (uint8_t) (ecc_tmp >> 16);
427 
428 	return 0;
429 }
430 
431 /*
432  * fsmc_read_hwecc_ecc1 - Hardware ECC calculator for ecc1 option supported by
433  * FSMC. ECC is 3 bytes for 512 bytes of data (supports error correction up to
434  * max of 1-bit)
435  */
436 static int fsmc_read_hwecc_ecc1(struct mtd_info *mtd, const uint8_t *data,
437 				uint8_t *ecc)
438 {
439 	struct fsmc_nand_data *host = mtd_to_fsmc(mtd);
440 	uint32_t ecc_tmp;
441 
442 	ecc_tmp = readl_relaxed(host->regs_va + ECC1);
443 	ecc[0] = (uint8_t) (ecc_tmp >> 0);
444 	ecc[1] = (uint8_t) (ecc_tmp >> 8);
445 	ecc[2] = (uint8_t) (ecc_tmp >> 16);
446 
447 	return 0;
448 }
449 
450 /* Count the number of 0's in buff upto a max of max_bits */
451 static int count_written_bits(uint8_t *buff, int size, int max_bits)
452 {
453 	int k, written_bits = 0;
454 
455 	for (k = 0; k < size; k++) {
456 		written_bits += hweight8(~buff[k]);
457 		if (written_bits > max_bits)
458 			break;
459 	}
460 
461 	return written_bits;
462 }
463 
464 static void dma_complete(void *param)
465 {
466 	struct fsmc_nand_data *host = param;
467 
468 	complete(&host->dma_access_complete);
469 }
470 
471 static int dma_xfer(struct fsmc_nand_data *host, void *buffer, int len,
472 		enum dma_data_direction direction)
473 {
474 	struct dma_chan *chan;
475 	struct dma_device *dma_dev;
476 	struct dma_async_tx_descriptor *tx;
477 	dma_addr_t dma_dst, dma_src, dma_addr;
478 	dma_cookie_t cookie;
479 	unsigned long flags = DMA_CTRL_ACK | DMA_PREP_INTERRUPT;
480 	int ret;
481 	unsigned long time_left;
482 
483 	if (direction == DMA_TO_DEVICE)
484 		chan = host->write_dma_chan;
485 	else if (direction == DMA_FROM_DEVICE)
486 		chan = host->read_dma_chan;
487 	else
488 		return -EINVAL;
489 
490 	dma_dev = chan->device;
491 	dma_addr = dma_map_single(dma_dev->dev, buffer, len, direction);
492 
493 	if (direction == DMA_TO_DEVICE) {
494 		dma_src = dma_addr;
495 		dma_dst = host->data_pa;
496 	} else {
497 		dma_src = host->data_pa;
498 		dma_dst = dma_addr;
499 	}
500 
501 	tx = dma_dev->device_prep_dma_memcpy(chan, dma_dst, dma_src,
502 			len, flags);
503 	if (!tx) {
504 		dev_err(host->dev, "device_prep_dma_memcpy error\n");
505 		ret = -EIO;
506 		goto unmap_dma;
507 	}
508 
509 	tx->callback = dma_complete;
510 	tx->callback_param = host;
511 	cookie = tx->tx_submit(tx);
512 
513 	ret = dma_submit_error(cookie);
514 	if (ret) {
515 		dev_err(host->dev, "dma_submit_error %d\n", cookie);
516 		goto unmap_dma;
517 	}
518 
519 	dma_async_issue_pending(chan);
520 
521 	time_left =
522 	wait_for_completion_timeout(&host->dma_access_complete,
523 				msecs_to_jiffies(3000));
524 	if (time_left == 0) {
525 		dmaengine_terminate_all(chan);
526 		dev_err(host->dev, "wait_for_completion_timeout\n");
527 		ret = -ETIMEDOUT;
528 		goto unmap_dma;
529 	}
530 
531 	ret = 0;
532 
533 unmap_dma:
534 	dma_unmap_single(dma_dev->dev, dma_addr, len, direction);
535 
536 	return ret;
537 }
538 
539 /*
540  * fsmc_write_buf - write buffer to chip
541  * @mtd:	MTD device structure
542  * @buf:	data buffer
543  * @len:	number of bytes to write
544  */
545 static void fsmc_write_buf(struct mtd_info *mtd, const uint8_t *buf, int len)
546 {
547 	struct fsmc_nand_data *host  = mtd_to_fsmc(mtd);
548 	int i;
549 
550 	if (IS_ALIGNED((uintptr_t)buf, sizeof(uint32_t)) &&
551 			IS_ALIGNED(len, sizeof(uint32_t))) {
552 		uint32_t *p = (uint32_t *)buf;
553 		len = len >> 2;
554 		for (i = 0; i < len; i++)
555 			writel_relaxed(p[i], host->data_va);
556 	} else {
557 		for (i = 0; i < len; i++)
558 			writeb_relaxed(buf[i], host->data_va);
559 	}
560 }
561 
562 /*
563  * fsmc_read_buf - read chip data into buffer
564  * @mtd:	MTD device structure
565  * @buf:	buffer to store date
566  * @len:	number of bytes to read
567  */
568 static void fsmc_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
569 {
570 	struct fsmc_nand_data *host  = mtd_to_fsmc(mtd);
571 	int i;
572 
573 	if (IS_ALIGNED((uintptr_t)buf, sizeof(uint32_t)) &&
574 			IS_ALIGNED(len, sizeof(uint32_t))) {
575 		uint32_t *p = (uint32_t *)buf;
576 		len = len >> 2;
577 		for (i = 0; i < len; i++)
578 			p[i] = readl_relaxed(host->data_va);
579 	} else {
580 		for (i = 0; i < len; i++)
581 			buf[i] = readb_relaxed(host->data_va);
582 	}
583 }
584 
585 /*
586  * fsmc_read_buf_dma - read chip data into buffer
587  * @mtd:	MTD device structure
588  * @buf:	buffer to store date
589  * @len:	number of bytes to read
590  */
591 static void fsmc_read_buf_dma(struct mtd_info *mtd, uint8_t *buf, int len)
592 {
593 	struct fsmc_nand_data *host  = mtd_to_fsmc(mtd);
594 
595 	dma_xfer(host, buf, len, DMA_FROM_DEVICE);
596 }
597 
598 /*
599  * fsmc_write_buf_dma - write buffer to chip
600  * @mtd:	MTD device structure
601  * @buf:	data buffer
602  * @len:	number of bytes to write
603  */
604 static void fsmc_write_buf_dma(struct mtd_info *mtd, const uint8_t *buf,
605 		int len)
606 {
607 	struct fsmc_nand_data *host = mtd_to_fsmc(mtd);
608 
609 	dma_xfer(host, (void *)buf, len, DMA_TO_DEVICE);
610 }
611 
612 /* fsmc_select_chip - assert or deassert nCE */
613 static void fsmc_select_chip(struct mtd_info *mtd, int chipnr)
614 {
615 	struct fsmc_nand_data *host = mtd_to_fsmc(mtd);
616 	u32 pc;
617 
618 	/* Support only one CS */
619 	if (chipnr > 0)
620 		return;
621 
622 	pc = readl(host->regs_va + FSMC_PC);
623 	if (chipnr < 0)
624 		writel_relaxed(pc & ~FSMC_ENABLE, host->regs_va + FSMC_PC);
625 	else
626 		writel_relaxed(pc | FSMC_ENABLE, host->regs_va + FSMC_PC);
627 
628 	/* nCE line must be asserted before starting any operation */
629 	mb();
630 }
631 
632 /*
633  * fsmc_exec_op - hook called by the core to execute NAND operations
634  *
635  * This controller is simple enough and thus does not need to use the parser
636  * provided by the core, instead, handle every situation here.
637  */
638 static int fsmc_exec_op(struct nand_chip *chip, const struct nand_operation *op,
639 			bool check_only)
640 {
641 	struct mtd_info *mtd = nand_to_mtd(chip);
642 	struct fsmc_nand_data *host = mtd_to_fsmc(mtd);
643 	const struct nand_op_instr *instr = NULL;
644 	int ret = 0;
645 	unsigned int op_id;
646 	int i;
647 
648 	pr_debug("Executing operation [%d instructions]:\n", op->ninstrs);
649 	for (op_id = 0; op_id < op->ninstrs; op_id++) {
650 		instr = &op->instrs[op_id];
651 
652 		switch (instr->type) {
653 		case NAND_OP_CMD_INSTR:
654 			pr_debug("  ->CMD      [0x%02x]\n",
655 				 instr->ctx.cmd.opcode);
656 
657 			writeb_relaxed(instr->ctx.cmd.opcode, host->cmd_va);
658 			break;
659 
660 		case NAND_OP_ADDR_INSTR:
661 			pr_debug("  ->ADDR     [%d cyc]",
662 				 instr->ctx.addr.naddrs);
663 
664 			for (i = 0; i < instr->ctx.addr.naddrs; i++)
665 				writeb_relaxed(instr->ctx.addr.addrs[i],
666 					       host->addr_va);
667 			break;
668 
669 		case NAND_OP_DATA_IN_INSTR:
670 			pr_debug("  ->DATA_IN  [%d B%s]\n", instr->ctx.data.len,
671 				 instr->ctx.data.force_8bit ?
672 				 ", force 8-bit" : "");
673 
674 			if (host->mode == USE_DMA_ACCESS)
675 				fsmc_read_buf_dma(mtd, instr->ctx.data.buf.in,
676 						  instr->ctx.data.len);
677 			else
678 				fsmc_read_buf(mtd, instr->ctx.data.buf.in,
679 					      instr->ctx.data.len);
680 			break;
681 
682 		case NAND_OP_DATA_OUT_INSTR:
683 			pr_debug("  ->DATA_OUT [%d B%s]\n", instr->ctx.data.len,
684 				 instr->ctx.data.force_8bit ?
685 				 ", force 8-bit" : "");
686 
687 			if (host->mode == USE_DMA_ACCESS)
688 				fsmc_write_buf_dma(mtd, instr->ctx.data.buf.out,
689 						   instr->ctx.data.len);
690 			else
691 				fsmc_write_buf(mtd, instr->ctx.data.buf.out,
692 					       instr->ctx.data.len);
693 			break;
694 
695 		case NAND_OP_WAITRDY_INSTR:
696 			pr_debug("  ->WAITRDY  [max %d ms]\n",
697 				 instr->ctx.waitrdy.timeout_ms);
698 
699 			ret = nand_soft_waitrdy(chip,
700 						instr->ctx.waitrdy.timeout_ms);
701 			break;
702 		}
703 	}
704 
705 	return ret;
706 }
707 
708 /*
709  * fsmc_read_page_hwecc
710  * @mtd:	mtd info structure
711  * @chip:	nand chip info structure
712  * @buf:	buffer to store read data
713  * @oob_required:	caller expects OOB data read to chip->oob_poi
714  * @page:	page number to read
715  *
716  * This routine is needed for fsmc version 8 as reading from NAND chip has to be
717  * performed in a strict sequence as follows:
718  * data(512 byte) -> ecc(13 byte)
719  * After this read, fsmc hardware generates and reports error data bits(up to a
720  * max of 8 bits)
721  */
722 static int fsmc_read_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
723 				 uint8_t *buf, int oob_required, int page)
724 {
725 	int i, j, s, stat, eccsize = chip->ecc.size;
726 	int eccbytes = chip->ecc.bytes;
727 	int eccsteps = chip->ecc.steps;
728 	uint8_t *p = buf;
729 	uint8_t *ecc_calc = chip->ecc.calc_buf;
730 	uint8_t *ecc_code = chip->ecc.code_buf;
731 	int off, len, group = 0;
732 	/*
733 	 * ecc_oob is intentionally taken as uint16_t. In 16bit devices, we
734 	 * end up reading 14 bytes (7 words) from oob. The local array is
735 	 * to maintain word alignment
736 	 */
737 	uint16_t ecc_oob[7];
738 	uint8_t *oob = (uint8_t *)&ecc_oob[0];
739 	unsigned int max_bitflips = 0;
740 
741 	for (i = 0, s = 0; s < eccsteps; s++, i += eccbytes, p += eccsize) {
742 		nand_read_page_op(chip, page, s * eccsize, NULL, 0);
743 		chip->ecc.hwctl(mtd, NAND_ECC_READ);
744 		nand_read_data_op(chip, p, eccsize, false);
745 
746 		for (j = 0; j < eccbytes;) {
747 			struct mtd_oob_region oobregion;
748 			int ret;
749 
750 			ret = mtd_ooblayout_ecc(mtd, group++, &oobregion);
751 			if (ret)
752 				return ret;
753 
754 			off = oobregion.offset;
755 			len = oobregion.length;
756 
757 			/*
758 			 * length is intentionally kept a higher multiple of 2
759 			 * to read at least 13 bytes even in case of 16 bit NAND
760 			 * devices
761 			 */
762 			if (chip->options & NAND_BUSWIDTH_16)
763 				len = roundup(len, 2);
764 
765 			nand_read_oob_op(chip, page, off, oob + j, len);
766 			j += len;
767 		}
768 
769 		memcpy(&ecc_code[i], oob, chip->ecc.bytes);
770 		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
771 
772 		stat = chip->ecc.correct(mtd, p, &ecc_code[i], &ecc_calc[i]);
773 		if (stat < 0) {
774 			mtd->ecc_stats.failed++;
775 		} else {
776 			mtd->ecc_stats.corrected += stat;
777 			max_bitflips = max_t(unsigned int, max_bitflips, stat);
778 		}
779 	}
780 
781 	return max_bitflips;
782 }
783 
784 /*
785  * fsmc_bch8_correct_data
786  * @mtd:	mtd info structure
787  * @dat:	buffer of read data
788  * @read_ecc:	ecc read from device spare area
789  * @calc_ecc:	ecc calculated from read data
790  *
791  * calc_ecc is a 104 bit information containing maximum of 8 error
792  * offset informations of 13 bits each in 512 bytes of read data.
793  */
794 static int fsmc_bch8_correct_data(struct mtd_info *mtd, uint8_t *dat,
795 			     uint8_t *read_ecc, uint8_t *calc_ecc)
796 {
797 	struct nand_chip *chip = mtd_to_nand(mtd);
798 	struct fsmc_nand_data *host = mtd_to_fsmc(mtd);
799 	uint32_t err_idx[8];
800 	uint32_t num_err, i;
801 	uint32_t ecc1, ecc2, ecc3, ecc4;
802 
803 	num_err = (readl_relaxed(host->regs_va + STS) >> 10) & 0xF;
804 
805 	/* no bit flipping */
806 	if (likely(num_err == 0))
807 		return 0;
808 
809 	/* too many errors */
810 	if (unlikely(num_err > 8)) {
811 		/*
812 		 * This is a temporary erase check. A newly erased page read
813 		 * would result in an ecc error because the oob data is also
814 		 * erased to FF and the calculated ecc for an FF data is not
815 		 * FF..FF.
816 		 * This is a workaround to skip performing correction in case
817 		 * data is FF..FF
818 		 *
819 		 * Logic:
820 		 * For every page, each bit written as 0 is counted until these
821 		 * number of bits are greater than 8 (the maximum correction
822 		 * capability of FSMC for each 512 + 13 bytes)
823 		 */
824 
825 		int bits_ecc = count_written_bits(read_ecc, chip->ecc.bytes, 8);
826 		int bits_data = count_written_bits(dat, chip->ecc.size, 8);
827 
828 		if ((bits_ecc + bits_data) <= 8) {
829 			if (bits_data)
830 				memset(dat, 0xff, chip->ecc.size);
831 			return bits_data;
832 		}
833 
834 		return -EBADMSG;
835 	}
836 
837 	/*
838 	 * ------------------- calc_ecc[] bit wise -----------|--13 bits--|
839 	 * |---idx[7]--|--.....-----|---idx[2]--||---idx[1]--||---idx[0]--|
840 	 *
841 	 * calc_ecc is a 104 bit information containing maximum of 8 error
842 	 * offset informations of 13 bits each. calc_ecc is copied into a
843 	 * uint64_t array and error offset indexes are populated in err_idx
844 	 * array
845 	 */
846 	ecc1 = readl_relaxed(host->regs_va + ECC1);
847 	ecc2 = readl_relaxed(host->regs_va + ECC2);
848 	ecc3 = readl_relaxed(host->regs_va + ECC3);
849 	ecc4 = readl_relaxed(host->regs_va + STS);
850 
851 	err_idx[0] = (ecc1 >> 0) & 0x1FFF;
852 	err_idx[1] = (ecc1 >> 13) & 0x1FFF;
853 	err_idx[2] = (((ecc2 >> 0) & 0x7F) << 6) | ((ecc1 >> 26) & 0x3F);
854 	err_idx[3] = (ecc2 >> 7) & 0x1FFF;
855 	err_idx[4] = (((ecc3 >> 0) & 0x1) << 12) | ((ecc2 >> 20) & 0xFFF);
856 	err_idx[5] = (ecc3 >> 1) & 0x1FFF;
857 	err_idx[6] = (ecc3 >> 14) & 0x1FFF;
858 	err_idx[7] = (((ecc4 >> 16) & 0xFF) << 5) | ((ecc3 >> 27) & 0x1F);
859 
860 	i = 0;
861 	while (num_err--) {
862 		change_bit(0, (unsigned long *)&err_idx[i]);
863 		change_bit(1, (unsigned long *)&err_idx[i]);
864 
865 		if (err_idx[i] < chip->ecc.size * 8) {
866 			change_bit(err_idx[i], (unsigned long *)dat);
867 			i++;
868 		}
869 	}
870 	return i;
871 }
872 
873 static bool filter(struct dma_chan *chan, void *slave)
874 {
875 	chan->private = slave;
876 	return true;
877 }
878 
879 static int fsmc_nand_probe_config_dt(struct platform_device *pdev,
880 				     struct fsmc_nand_data *host,
881 				     struct nand_chip *nand)
882 {
883 	struct device_node *np = pdev->dev.of_node;
884 	u32 val;
885 	int ret;
886 
887 	nand->options = 0;
888 
889 	if (!of_property_read_u32(np, "bank-width", &val)) {
890 		if (val == 2) {
891 			nand->options |= NAND_BUSWIDTH_16;
892 		} else if (val != 1) {
893 			dev_err(&pdev->dev, "invalid bank-width %u\n", val);
894 			return -EINVAL;
895 		}
896 	}
897 
898 	if (of_get_property(np, "nand-skip-bbtscan", NULL))
899 		nand->options |= NAND_SKIP_BBTSCAN;
900 
901 	host->dev_timings = devm_kzalloc(&pdev->dev,
902 				sizeof(*host->dev_timings), GFP_KERNEL);
903 	if (!host->dev_timings)
904 		return -ENOMEM;
905 	ret = of_property_read_u8_array(np, "timings", (u8 *)host->dev_timings,
906 						sizeof(*host->dev_timings));
907 	if (ret)
908 		host->dev_timings = NULL;
909 
910 	/* Set default NAND bank to 0 */
911 	host->bank = 0;
912 	if (!of_property_read_u32(np, "bank", &val)) {
913 		if (val > 3) {
914 			dev_err(&pdev->dev, "invalid bank %u\n", val);
915 			return -EINVAL;
916 		}
917 		host->bank = val;
918 	}
919 	return 0;
920 }
921 
922 static int fsmc_nand_attach_chip(struct nand_chip *nand)
923 {
924 	struct mtd_info *mtd = nand_to_mtd(nand);
925 	struct fsmc_nand_data *host = mtd_to_fsmc(mtd);
926 
927 	if (AMBA_REV_BITS(host->pid) >= 8) {
928 		switch (mtd->oobsize) {
929 		case 16:
930 		case 64:
931 		case 128:
932 		case 224:
933 		case 256:
934 			break;
935 		default:
936 			dev_warn(host->dev,
937 				 "No oob scheme defined for oobsize %d\n",
938 				 mtd->oobsize);
939 			return -EINVAL;
940 		}
941 
942 		mtd_set_ooblayout(mtd, &fsmc_ecc4_ooblayout_ops);
943 
944 		return 0;
945 	}
946 
947 	switch (nand->ecc.mode) {
948 	case NAND_ECC_HW:
949 		dev_info(host->dev, "Using 1-bit HW ECC scheme\n");
950 		nand->ecc.calculate = fsmc_read_hwecc_ecc1;
951 		nand->ecc.correct = nand_correct_data;
952 		nand->ecc.bytes = 3;
953 		nand->ecc.strength = 1;
954 		break;
955 
956 	case NAND_ECC_SOFT:
957 		if (nand->ecc.algo == NAND_ECC_BCH) {
958 			dev_info(host->dev,
959 				 "Using 4-bit SW BCH ECC scheme\n");
960 			break;
961 		}
962 
963 	case NAND_ECC_ON_DIE:
964 		break;
965 
966 	default:
967 		dev_err(host->dev, "Unsupported ECC mode!\n");
968 		return -ENOTSUPP;
969 	}
970 
971 	/*
972 	 * Don't set layout for BCH4 SW ECC. This will be
973 	 * generated later in nand_bch_init() later.
974 	 */
975 	if (nand->ecc.mode == NAND_ECC_HW) {
976 		switch (mtd->oobsize) {
977 		case 16:
978 		case 64:
979 		case 128:
980 			mtd_set_ooblayout(mtd,
981 					  &fsmc_ecc1_ooblayout_ops);
982 			break;
983 		default:
984 			dev_warn(host->dev,
985 				 "No oob scheme defined for oobsize %d\n",
986 				 mtd->oobsize);
987 			return -EINVAL;
988 		}
989 	}
990 
991 	return 0;
992 }
993 
994 static const struct nand_controller_ops fsmc_nand_controller_ops = {
995 	.attach_chip = fsmc_nand_attach_chip,
996 };
997 
998 /*
999  * fsmc_nand_probe - Probe function
1000  * @pdev:       platform device structure
1001  */
1002 static int __init fsmc_nand_probe(struct platform_device *pdev)
1003 {
1004 	struct fsmc_nand_data *host;
1005 	struct mtd_info *mtd;
1006 	struct nand_chip *nand;
1007 	struct resource *res;
1008 	void __iomem *base;
1009 	dma_cap_mask_t mask;
1010 	int ret = 0;
1011 	u32 pid;
1012 	int i;
1013 
1014 	/* Allocate memory for the device structure (and zero it) */
1015 	host = devm_kzalloc(&pdev->dev, sizeof(*host), GFP_KERNEL);
1016 	if (!host)
1017 		return -ENOMEM;
1018 
1019 	nand = &host->nand;
1020 
1021 	ret = fsmc_nand_probe_config_dt(pdev, host, nand);
1022 	if (ret)
1023 		return ret;
1024 
1025 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "nand_data");
1026 	host->data_va = devm_ioremap_resource(&pdev->dev, res);
1027 	if (IS_ERR(host->data_va))
1028 		return PTR_ERR(host->data_va);
1029 
1030 	host->data_pa = (dma_addr_t)res->start;
1031 
1032 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "nand_addr");
1033 	host->addr_va = devm_ioremap_resource(&pdev->dev, res);
1034 	if (IS_ERR(host->addr_va))
1035 		return PTR_ERR(host->addr_va);
1036 
1037 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "nand_cmd");
1038 	host->cmd_va = devm_ioremap_resource(&pdev->dev, res);
1039 	if (IS_ERR(host->cmd_va))
1040 		return PTR_ERR(host->cmd_va);
1041 
1042 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "fsmc_regs");
1043 	base = devm_ioremap_resource(&pdev->dev, res);
1044 	if (IS_ERR(base))
1045 		return PTR_ERR(base);
1046 
1047 	host->regs_va = base + FSMC_NOR_REG_SIZE +
1048 		(host->bank * FSMC_NAND_BANK_SZ);
1049 
1050 	host->clk = devm_clk_get(&pdev->dev, NULL);
1051 	if (IS_ERR(host->clk)) {
1052 		dev_err(&pdev->dev, "failed to fetch block clock\n");
1053 		return PTR_ERR(host->clk);
1054 	}
1055 
1056 	ret = clk_prepare_enable(host->clk);
1057 	if (ret)
1058 		return ret;
1059 
1060 	/*
1061 	 * This device ID is actually a common AMBA ID as used on the
1062 	 * AMBA PrimeCell bus. However it is not a PrimeCell.
1063 	 */
1064 	for (pid = 0, i = 0; i < 4; i++)
1065 		pid |= (readl(base + resource_size(res) - 0x20 + 4 * i) & 255) << (i * 8);
1066 	host->pid = pid;
1067 	dev_info(&pdev->dev, "FSMC device partno %03x, manufacturer %02x, "
1068 		 "revision %02x, config %02x\n",
1069 		 AMBA_PART_BITS(pid), AMBA_MANF_BITS(pid),
1070 		 AMBA_REV_BITS(pid), AMBA_CONFIG_BITS(pid));
1071 
1072 	host->dev = &pdev->dev;
1073 
1074 	if (host->mode == USE_DMA_ACCESS)
1075 		init_completion(&host->dma_access_complete);
1076 
1077 	/* Link all private pointers */
1078 	mtd = nand_to_mtd(&host->nand);
1079 	nand_set_controller_data(nand, host);
1080 	nand_set_flash_node(nand, pdev->dev.of_node);
1081 
1082 	mtd->dev.parent = &pdev->dev;
1083 	nand->exec_op = fsmc_exec_op;
1084 	nand->select_chip = fsmc_select_chip;
1085 	nand->chip_delay = 30;
1086 
1087 	/*
1088 	 * Setup default ECC mode. nand_dt_init() called from nand_scan_ident()
1089 	 * can overwrite this value if the DT provides a different value.
1090 	 */
1091 	nand->ecc.mode = NAND_ECC_HW;
1092 	nand->ecc.hwctl = fsmc_enable_hwecc;
1093 	nand->ecc.size = 512;
1094 	nand->badblockbits = 7;
1095 
1096 	if (host->mode == USE_DMA_ACCESS) {
1097 		dma_cap_zero(mask);
1098 		dma_cap_set(DMA_MEMCPY, mask);
1099 		host->read_dma_chan = dma_request_channel(mask, filter, NULL);
1100 		if (!host->read_dma_chan) {
1101 			dev_err(&pdev->dev, "Unable to get read dma channel\n");
1102 			goto disable_clk;
1103 		}
1104 		host->write_dma_chan = dma_request_channel(mask, filter, NULL);
1105 		if (!host->write_dma_chan) {
1106 			dev_err(&pdev->dev, "Unable to get write dma channel\n");
1107 			goto release_dma_read_chan;
1108 		}
1109 	}
1110 
1111 	if (host->dev_timings)
1112 		fsmc_nand_setup(host, host->dev_timings);
1113 	else
1114 		nand->setup_data_interface = fsmc_setup_data_interface;
1115 
1116 	if (AMBA_REV_BITS(host->pid) >= 8) {
1117 		nand->ecc.read_page = fsmc_read_page_hwecc;
1118 		nand->ecc.calculate = fsmc_read_hwecc_ecc4;
1119 		nand->ecc.correct = fsmc_bch8_correct_data;
1120 		nand->ecc.bytes = 13;
1121 		nand->ecc.strength = 8;
1122 	}
1123 
1124 	/*
1125 	 * Scan to find existence of the device
1126 	 */
1127 	nand->dummy_controller.ops = &fsmc_nand_controller_ops;
1128 	ret = nand_scan(mtd, 1);
1129 	if (ret)
1130 		goto release_dma_write_chan;
1131 
1132 	mtd->name = "nand";
1133 	ret = mtd_device_register(mtd, NULL, 0);
1134 	if (ret)
1135 		goto cleanup_nand;
1136 
1137 	platform_set_drvdata(pdev, host);
1138 	dev_info(&pdev->dev, "FSMC NAND driver registration successful\n");
1139 
1140 	return 0;
1141 
1142 cleanup_nand:
1143 	nand_cleanup(nand);
1144 release_dma_write_chan:
1145 	if (host->mode == USE_DMA_ACCESS)
1146 		dma_release_channel(host->write_dma_chan);
1147 release_dma_read_chan:
1148 	if (host->mode == USE_DMA_ACCESS)
1149 		dma_release_channel(host->read_dma_chan);
1150 disable_clk:
1151 	clk_disable_unprepare(host->clk);
1152 
1153 	return ret;
1154 }
1155 
1156 /*
1157  * Clean up routine
1158  */
1159 static int fsmc_nand_remove(struct platform_device *pdev)
1160 {
1161 	struct fsmc_nand_data *host = platform_get_drvdata(pdev);
1162 
1163 	if (host) {
1164 		nand_release(nand_to_mtd(&host->nand));
1165 
1166 		if (host->mode == USE_DMA_ACCESS) {
1167 			dma_release_channel(host->write_dma_chan);
1168 			dma_release_channel(host->read_dma_chan);
1169 		}
1170 		clk_disable_unprepare(host->clk);
1171 	}
1172 
1173 	return 0;
1174 }
1175 
1176 #ifdef CONFIG_PM_SLEEP
1177 static int fsmc_nand_suspend(struct device *dev)
1178 {
1179 	struct fsmc_nand_data *host = dev_get_drvdata(dev);
1180 	if (host)
1181 		clk_disable_unprepare(host->clk);
1182 	return 0;
1183 }
1184 
1185 static int fsmc_nand_resume(struct device *dev)
1186 {
1187 	struct fsmc_nand_data *host = dev_get_drvdata(dev);
1188 	if (host) {
1189 		clk_prepare_enable(host->clk);
1190 		if (host->dev_timings)
1191 			fsmc_nand_setup(host, host->dev_timings);
1192 	}
1193 	return 0;
1194 }
1195 #endif
1196 
1197 static SIMPLE_DEV_PM_OPS(fsmc_nand_pm_ops, fsmc_nand_suspend, fsmc_nand_resume);
1198 
1199 static const struct of_device_id fsmc_nand_id_table[] = {
1200 	{ .compatible = "st,spear600-fsmc-nand" },
1201 	{ .compatible = "stericsson,fsmc-nand" },
1202 	{}
1203 };
1204 MODULE_DEVICE_TABLE(of, fsmc_nand_id_table);
1205 
1206 static struct platform_driver fsmc_nand_driver = {
1207 	.remove = fsmc_nand_remove,
1208 	.driver = {
1209 		.name = "fsmc-nand",
1210 		.of_match_table = fsmc_nand_id_table,
1211 		.pm = &fsmc_nand_pm_ops,
1212 	},
1213 };
1214 
1215 module_platform_driver_probe(fsmc_nand_driver, fsmc_nand_probe);
1216 
1217 MODULE_LICENSE("GPL");
1218 MODULE_AUTHOR("Vipin Kumar <vipin.kumar@st.com>, Ashish Priyadarshi");
1219 MODULE_DESCRIPTION("NAND driver for SPEAr Platforms");
1220