xref: /openbmc/linux/drivers/mtd/nand/raw/fsmc_nand.c (revision 2a598d0b)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * ST Microelectronics
4  * Flexible Static Memory Controller (FSMC)
5  * Driver for NAND portions
6  *
7  * Copyright © 2010 ST Microelectronics
8  * Vipin Kumar <vipin.kumar@st.com>
9  * Ashish Priyadarshi
10  *
11  * Based on drivers/mtd/nand/nomadik_nand.c (removed in v3.8)
12  *  Copyright © 2007 STMicroelectronics Pvt. Ltd.
13  *  Copyright © 2009 Alessandro Rubini
14  */
15 
16 #include <linux/clk.h>
17 #include <linux/completion.h>
18 #include <linux/delay.h>
19 #include <linux/dmaengine.h>
20 #include <linux/dma-direction.h>
21 #include <linux/dma-mapping.h>
22 #include <linux/err.h>
23 #include <linux/init.h>
24 #include <linux/module.h>
25 #include <linux/resource.h>
26 #include <linux/sched.h>
27 #include <linux/types.h>
28 #include <linux/mtd/mtd.h>
29 #include <linux/mtd/nand-ecc-sw-hamming.h>
30 #include <linux/mtd/rawnand.h>
31 #include <linux/platform_device.h>
32 #include <linux/of.h>
33 #include <linux/mtd/partitions.h>
34 #include <linux/io.h>
35 #include <linux/slab.h>
36 #include <linux/amba/bus.h>
37 #include <mtd/mtd-abi.h>
38 
39 /* fsmc controller registers for NOR flash */
40 #define CTRL			0x0
41 	/* ctrl register definitions */
42 	#define BANK_ENABLE		BIT(0)
43 	#define MUXED			BIT(1)
44 	#define NOR_DEV			(2 << 2)
45 	#define WIDTH_16		BIT(4)
46 	#define RSTPWRDWN		BIT(6)
47 	#define WPROT			BIT(7)
48 	#define WRT_ENABLE		BIT(12)
49 	#define WAIT_ENB		BIT(13)
50 
51 #define CTRL_TIM		0x4
52 	/* ctrl_tim register definitions */
53 
54 #define FSMC_NOR_BANK_SZ	0x8
55 #define FSMC_NOR_REG_SIZE	0x40
56 
57 #define FSMC_NOR_REG(base, bank, reg)	((base) +			\
58 					 (FSMC_NOR_BANK_SZ * (bank)) +	\
59 					 (reg))
60 
61 /* fsmc controller registers for NAND flash */
62 #define FSMC_PC			0x00
63 	/* pc register definitions */
64 	#define FSMC_RESET		BIT(0)
65 	#define FSMC_WAITON		BIT(1)
66 	#define FSMC_ENABLE		BIT(2)
67 	#define FSMC_DEVTYPE_NAND	BIT(3)
68 	#define FSMC_DEVWID_16		BIT(4)
69 	#define FSMC_ECCEN		BIT(6)
70 	#define FSMC_ECCPLEN_256	BIT(7)
71 	#define FSMC_TCLR_SHIFT		(9)
72 	#define FSMC_TCLR_MASK		(0xF)
73 	#define FSMC_TAR_SHIFT		(13)
74 	#define FSMC_TAR_MASK		(0xF)
75 #define STS			0x04
76 	/* sts register definitions */
77 	#define FSMC_CODE_RDY		BIT(15)
78 #define COMM			0x08
79 	/* comm register definitions */
80 	#define FSMC_TSET_SHIFT		0
81 	#define FSMC_TSET_MASK		0xFF
82 	#define FSMC_TWAIT_SHIFT	8
83 	#define FSMC_TWAIT_MASK		0xFF
84 	#define FSMC_THOLD_SHIFT	16
85 	#define FSMC_THOLD_MASK		0xFF
86 	#define FSMC_THIZ_SHIFT		24
87 	#define FSMC_THIZ_MASK		0xFF
88 #define ATTRIB			0x0C
89 #define IOATA			0x10
90 #define ECC1			0x14
91 #define ECC2			0x18
92 #define ECC3			0x1C
93 #define FSMC_NAND_BANK_SZ	0x20
94 
95 #define FSMC_BUSY_WAIT_TIMEOUT	(1 * HZ)
96 
97 /*
98  * According to SPEAr300 Reference Manual (RM0082)
99  *  TOUDEL = 7ns (Output delay from the flip-flops to the board)
100  *  TINDEL = 5ns (Input delay from the board to the flipflop)
101  */
102 #define TOUTDEL	7000
103 #define TINDEL	5000
104 
105 struct fsmc_nand_timings {
106 	u8 tclr;
107 	u8 tar;
108 	u8 thiz;
109 	u8 thold;
110 	u8 twait;
111 	u8 tset;
112 };
113 
114 enum access_mode {
115 	USE_DMA_ACCESS = 1,
116 	USE_WORD_ACCESS,
117 };
118 
119 /**
120  * struct fsmc_nand_data - structure for FSMC NAND device state
121  *
122  * @base:		Inherit from the nand_controller struct
123  * @pid:		Part ID on the AMBA PrimeCell format
124  * @nand:		Chip related info for a NAND flash.
125  *
126  * @bank:		Bank number for probed device.
127  * @dev:		Parent device
128  * @mode:		Access mode
129  * @clk:		Clock structure for FSMC.
130  *
131  * @read_dma_chan:	DMA channel for read access
132  * @write_dma_chan:	DMA channel for write access to NAND
133  * @dma_access_complete: Completion structure
134  *
135  * @dev_timings:	NAND timings
136  *
137  * @data_pa:		NAND Physical port for Data.
138  * @data_va:		NAND port for Data.
139  * @cmd_va:		NAND port for Command.
140  * @addr_va:		NAND port for Address.
141  * @regs_va:		Registers base address for a given bank.
142  */
143 struct fsmc_nand_data {
144 	struct nand_controller	base;
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 *nand_to_fsmc(struct nand_chip *chip)
252 {
253 	return container_of(chip, 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 	u32 value = FSMC_DEVTYPE_NAND | FSMC_ENABLE | FSMC_WAITON;
266 	u32 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 		value |= FSMC_DEVWID_16;
277 
278 	writel_relaxed(value | tclr | tar, host->regs_va + FSMC_PC);
279 	writel_relaxed(thiz | thold | twait | tset, host->regs_va + COMM);
280 	writel_relaxed(thiz | thold | twait | tset, host->regs_va + ATTRIB);
281 }
282 
283 static int fsmc_calc_timings(struct fsmc_nand_data *host,
284 			     const struct nand_sdr_timings *sdrt,
285 			     struct fsmc_nand_timings *tims)
286 {
287 	unsigned long hclk = clk_get_rate(host->clk);
288 	unsigned long hclkn = NSEC_PER_SEC / hclk;
289 	u32 thiz, thold, twait, tset, twait_min;
290 
291 	if (sdrt->tRC_min < 30000)
292 		return -EOPNOTSUPP;
293 
294 	tims->tar = DIV_ROUND_UP(sdrt->tAR_min / 1000, hclkn) - 1;
295 	if (tims->tar > FSMC_TAR_MASK)
296 		tims->tar = FSMC_TAR_MASK;
297 	tims->tclr = DIV_ROUND_UP(sdrt->tCLR_min / 1000, hclkn) - 1;
298 	if (tims->tclr > FSMC_TCLR_MASK)
299 		tims->tclr = FSMC_TCLR_MASK;
300 
301 	thiz = sdrt->tCS_min - sdrt->tWP_min;
302 	tims->thiz = DIV_ROUND_UP(thiz / 1000, hclkn);
303 
304 	thold = sdrt->tDH_min;
305 	if (thold < sdrt->tCH_min)
306 		thold = sdrt->tCH_min;
307 	if (thold < sdrt->tCLH_min)
308 		thold = sdrt->tCLH_min;
309 	if (thold < sdrt->tWH_min)
310 		thold = sdrt->tWH_min;
311 	if (thold < sdrt->tALH_min)
312 		thold = sdrt->tALH_min;
313 	if (thold < sdrt->tREH_min)
314 		thold = sdrt->tREH_min;
315 	tims->thold = DIV_ROUND_UP(thold / 1000, hclkn);
316 	if (tims->thold == 0)
317 		tims->thold = 1;
318 	else if (tims->thold > FSMC_THOLD_MASK)
319 		tims->thold = FSMC_THOLD_MASK;
320 
321 	tset = max(sdrt->tCS_min - sdrt->tWP_min,
322 		   sdrt->tCEA_max - sdrt->tREA_max);
323 	tims->tset = DIV_ROUND_UP(tset / 1000, hclkn) - 1;
324 	if (tims->tset == 0)
325 		tims->tset = 1;
326 	else if (tims->tset > FSMC_TSET_MASK)
327 		tims->tset = FSMC_TSET_MASK;
328 
329 	/*
330 	 * According to SPEAr300 Reference Manual (RM0082) which gives more
331 	 * information related to FSMSC timings than the SPEAr600 one (RM0305),
332 	 *   twait >= tCEA - (tset * TCLK) + TOUTDEL + TINDEL
333 	 */
334 	twait_min = sdrt->tCEA_max - ((tims->tset + 1) * hclkn * 1000)
335 		    + TOUTDEL + TINDEL;
336 	twait = max3(sdrt->tRP_min, sdrt->tWP_min, twait_min);
337 
338 	tims->twait = DIV_ROUND_UP(twait / 1000, hclkn) - 1;
339 	if (tims->twait == 0)
340 		tims->twait = 1;
341 	else if (tims->twait > FSMC_TWAIT_MASK)
342 		tims->twait = FSMC_TWAIT_MASK;
343 
344 	return 0;
345 }
346 
347 static int fsmc_setup_interface(struct nand_chip *nand, int csline,
348 				const struct nand_interface_config *conf)
349 {
350 	struct fsmc_nand_data *host = nand_to_fsmc(nand);
351 	struct fsmc_nand_timings tims;
352 	const struct nand_sdr_timings *sdrt;
353 	int ret;
354 
355 	sdrt = nand_get_sdr_timings(conf);
356 	if (IS_ERR(sdrt))
357 		return PTR_ERR(sdrt);
358 
359 	ret = fsmc_calc_timings(host, sdrt, &tims);
360 	if (ret)
361 		return ret;
362 
363 	if (csline == NAND_DATA_IFACE_CHECK_ONLY)
364 		return 0;
365 
366 	fsmc_nand_setup(host, &tims);
367 
368 	return 0;
369 }
370 
371 /*
372  * fsmc_enable_hwecc - Enables Hardware ECC through FSMC registers
373  */
374 static void fsmc_enable_hwecc(struct nand_chip *chip, int mode)
375 {
376 	struct fsmc_nand_data *host = nand_to_fsmc(chip);
377 
378 	writel_relaxed(readl(host->regs_va + FSMC_PC) & ~FSMC_ECCPLEN_256,
379 		       host->regs_va + FSMC_PC);
380 	writel_relaxed(readl(host->regs_va + FSMC_PC) & ~FSMC_ECCEN,
381 		       host->regs_va + FSMC_PC);
382 	writel_relaxed(readl(host->regs_va + FSMC_PC) | FSMC_ECCEN,
383 		       host->regs_va + FSMC_PC);
384 }
385 
386 /*
387  * fsmc_read_hwecc_ecc4 - Hardware ECC calculator for ecc4 option supported by
388  * FSMC. ECC is 13 bytes for 512 bytes of data (supports error correction up to
389  * max of 8-bits)
390  */
391 static int fsmc_read_hwecc_ecc4(struct nand_chip *chip, const u8 *data,
392 				u8 *ecc)
393 {
394 	struct fsmc_nand_data *host = nand_to_fsmc(chip);
395 	u32 ecc_tmp;
396 	unsigned long deadline = jiffies + FSMC_BUSY_WAIT_TIMEOUT;
397 
398 	do {
399 		if (readl_relaxed(host->regs_va + STS) & FSMC_CODE_RDY)
400 			break;
401 
402 		cond_resched();
403 	} while (!time_after_eq(jiffies, deadline));
404 
405 	if (time_after_eq(jiffies, deadline)) {
406 		dev_err(host->dev, "calculate ecc timed out\n");
407 		return -ETIMEDOUT;
408 	}
409 
410 	ecc_tmp = readl_relaxed(host->regs_va + ECC1);
411 	ecc[0] = ecc_tmp;
412 	ecc[1] = ecc_tmp >> 8;
413 	ecc[2] = ecc_tmp >> 16;
414 	ecc[3] = ecc_tmp >> 24;
415 
416 	ecc_tmp = readl_relaxed(host->regs_va + ECC2);
417 	ecc[4] = ecc_tmp;
418 	ecc[5] = ecc_tmp >> 8;
419 	ecc[6] = ecc_tmp >> 16;
420 	ecc[7] = ecc_tmp >> 24;
421 
422 	ecc_tmp = readl_relaxed(host->regs_va + ECC3);
423 	ecc[8] = ecc_tmp;
424 	ecc[9] = ecc_tmp >> 8;
425 	ecc[10] = ecc_tmp >> 16;
426 	ecc[11] = ecc_tmp >> 24;
427 
428 	ecc_tmp = readl_relaxed(host->regs_va + STS);
429 	ecc[12] = ecc_tmp >> 16;
430 
431 	return 0;
432 }
433 
434 /*
435  * fsmc_read_hwecc_ecc1 - Hardware ECC calculator for ecc1 option supported by
436  * FSMC. ECC is 3 bytes for 512 bytes of data (supports error correction up to
437  * max of 1-bit)
438  */
439 static int fsmc_read_hwecc_ecc1(struct nand_chip *chip, const u8 *data,
440 				u8 *ecc)
441 {
442 	struct fsmc_nand_data *host = nand_to_fsmc(chip);
443 	u32 ecc_tmp;
444 
445 	ecc_tmp = readl_relaxed(host->regs_va + ECC1);
446 	ecc[0] = ecc_tmp;
447 	ecc[1] = ecc_tmp >> 8;
448 	ecc[2] = ecc_tmp >> 16;
449 
450 	return 0;
451 }
452 
453 static int fsmc_correct_ecc1(struct nand_chip *chip,
454 			     unsigned char *buf,
455 			     unsigned char *read_ecc,
456 			     unsigned char *calc_ecc)
457 {
458 	bool sm_order = chip->ecc.options & NAND_ECC_SOFT_HAMMING_SM_ORDER;
459 
460 	return ecc_sw_hamming_correct(buf, read_ecc, calc_ecc,
461 				      chip->ecc.size, sm_order);
462 }
463 
464 /* Count the number of 0's in buff upto a max of max_bits */
465 static int count_written_bits(u8 *buff, int size, int max_bits)
466 {
467 	int k, written_bits = 0;
468 
469 	for (k = 0; k < size; k++) {
470 		written_bits += hweight8(~buff[k]);
471 		if (written_bits > max_bits)
472 			break;
473 	}
474 
475 	return written_bits;
476 }
477 
478 static void dma_complete(void *param)
479 {
480 	struct fsmc_nand_data *host = param;
481 
482 	complete(&host->dma_access_complete);
483 }
484 
485 static int dma_xfer(struct fsmc_nand_data *host, void *buffer, int len,
486 		    enum dma_data_direction direction)
487 {
488 	struct dma_chan *chan;
489 	struct dma_device *dma_dev;
490 	struct dma_async_tx_descriptor *tx;
491 	dma_addr_t dma_dst, dma_src, dma_addr;
492 	dma_cookie_t cookie;
493 	unsigned long flags = DMA_CTRL_ACK | DMA_PREP_INTERRUPT;
494 	int ret;
495 	unsigned long time_left;
496 
497 	if (direction == DMA_TO_DEVICE)
498 		chan = host->write_dma_chan;
499 	else if (direction == DMA_FROM_DEVICE)
500 		chan = host->read_dma_chan;
501 	else
502 		return -EINVAL;
503 
504 	dma_dev = chan->device;
505 	dma_addr = dma_map_single(dma_dev->dev, buffer, len, direction);
506 
507 	if (direction == DMA_TO_DEVICE) {
508 		dma_src = dma_addr;
509 		dma_dst = host->data_pa;
510 	} else {
511 		dma_src = host->data_pa;
512 		dma_dst = dma_addr;
513 	}
514 
515 	tx = dma_dev->device_prep_dma_memcpy(chan, dma_dst, dma_src,
516 			len, flags);
517 	if (!tx) {
518 		dev_err(host->dev, "device_prep_dma_memcpy error\n");
519 		ret = -EIO;
520 		goto unmap_dma;
521 	}
522 
523 	tx->callback = dma_complete;
524 	tx->callback_param = host;
525 	cookie = tx->tx_submit(tx);
526 
527 	ret = dma_submit_error(cookie);
528 	if (ret) {
529 		dev_err(host->dev, "dma_submit_error %d\n", cookie);
530 		goto unmap_dma;
531 	}
532 
533 	dma_async_issue_pending(chan);
534 
535 	time_left =
536 	wait_for_completion_timeout(&host->dma_access_complete,
537 				    msecs_to_jiffies(3000));
538 	if (time_left == 0) {
539 		dmaengine_terminate_all(chan);
540 		dev_err(host->dev, "wait_for_completion_timeout\n");
541 		ret = -ETIMEDOUT;
542 		goto unmap_dma;
543 	}
544 
545 	ret = 0;
546 
547 unmap_dma:
548 	dma_unmap_single(dma_dev->dev, dma_addr, len, direction);
549 
550 	return ret;
551 }
552 
553 /*
554  * fsmc_write_buf - write buffer to chip
555  * @host:	FSMC NAND controller
556  * @buf:	data buffer
557  * @len:	number of bytes to write
558  */
559 static void fsmc_write_buf(struct fsmc_nand_data *host, const u8 *buf,
560 			   int len)
561 {
562 	int i;
563 
564 	if (IS_ALIGNED((uintptr_t)buf, sizeof(u32)) &&
565 	    IS_ALIGNED(len, sizeof(u32))) {
566 		u32 *p = (u32 *)buf;
567 
568 		len = len >> 2;
569 		for (i = 0; i < len; i++)
570 			writel_relaxed(p[i], host->data_va);
571 	} else {
572 		for (i = 0; i < len; i++)
573 			writeb_relaxed(buf[i], host->data_va);
574 	}
575 }
576 
577 /*
578  * fsmc_read_buf - read chip data into buffer
579  * @host:	FSMC NAND controller
580  * @buf:	buffer to store date
581  * @len:	number of bytes to read
582  */
583 static void fsmc_read_buf(struct fsmc_nand_data *host, u8 *buf, int len)
584 {
585 	int i;
586 
587 	if (IS_ALIGNED((uintptr_t)buf, sizeof(u32)) &&
588 	    IS_ALIGNED(len, sizeof(u32))) {
589 		u32 *p = (u32 *)buf;
590 
591 		len = len >> 2;
592 		for (i = 0; i < len; i++)
593 			p[i] = readl_relaxed(host->data_va);
594 	} else {
595 		for (i = 0; i < len; i++)
596 			buf[i] = readb_relaxed(host->data_va);
597 	}
598 }
599 
600 /*
601  * fsmc_read_buf_dma - read chip data into buffer
602  * @host:	FSMC NAND controller
603  * @buf:	buffer to store date
604  * @len:	number of bytes to read
605  */
606 static void fsmc_read_buf_dma(struct fsmc_nand_data *host, u8 *buf,
607 			      int len)
608 {
609 	dma_xfer(host, buf, len, DMA_FROM_DEVICE);
610 }
611 
612 /*
613  * fsmc_write_buf_dma - write buffer to chip
614  * @host:	FSMC NAND controller
615  * @buf:	data buffer
616  * @len:	number of bytes to write
617  */
618 static void fsmc_write_buf_dma(struct fsmc_nand_data *host, const u8 *buf,
619 			       int len)
620 {
621 	dma_xfer(host, (void *)buf, len, DMA_TO_DEVICE);
622 }
623 
624 /*
625  * fsmc_exec_op - hook called by the core to execute NAND operations
626  *
627  * This controller is simple enough and thus does not need to use the parser
628  * provided by the core, instead, handle every situation here.
629  */
630 static int fsmc_exec_op(struct nand_chip *chip, const struct nand_operation *op,
631 			bool check_only)
632 {
633 	struct fsmc_nand_data *host = nand_to_fsmc(chip);
634 	const struct nand_op_instr *instr = NULL;
635 	int ret = 0;
636 	unsigned int op_id;
637 	int i;
638 
639 	if (check_only)
640 		return 0;
641 
642 	pr_debug("Executing operation [%d instructions]:\n", op->ninstrs);
643 
644 	for (op_id = 0; op_id < op->ninstrs; op_id++) {
645 		instr = &op->instrs[op_id];
646 
647 		nand_op_trace("  ", instr);
648 
649 		switch (instr->type) {
650 		case NAND_OP_CMD_INSTR:
651 			writeb_relaxed(instr->ctx.cmd.opcode, host->cmd_va);
652 			break;
653 
654 		case NAND_OP_ADDR_INSTR:
655 			for (i = 0; i < instr->ctx.addr.naddrs; i++)
656 				writeb_relaxed(instr->ctx.addr.addrs[i],
657 					       host->addr_va);
658 			break;
659 
660 		case NAND_OP_DATA_IN_INSTR:
661 			if (host->mode == USE_DMA_ACCESS)
662 				fsmc_read_buf_dma(host, instr->ctx.data.buf.in,
663 						  instr->ctx.data.len);
664 			else
665 				fsmc_read_buf(host, instr->ctx.data.buf.in,
666 					      instr->ctx.data.len);
667 			break;
668 
669 		case NAND_OP_DATA_OUT_INSTR:
670 			if (host->mode == USE_DMA_ACCESS)
671 				fsmc_write_buf_dma(host,
672 						   instr->ctx.data.buf.out,
673 						   instr->ctx.data.len);
674 			else
675 				fsmc_write_buf(host, instr->ctx.data.buf.out,
676 					       instr->ctx.data.len);
677 			break;
678 
679 		case NAND_OP_WAITRDY_INSTR:
680 			ret = nand_soft_waitrdy(chip,
681 						instr->ctx.waitrdy.timeout_ms);
682 			break;
683 		}
684 
685 		if (instr->delay_ns)
686 			ndelay(instr->delay_ns);
687 	}
688 
689 	return ret;
690 }
691 
692 /*
693  * fsmc_read_page_hwecc
694  * @chip:	nand chip info structure
695  * @buf:	buffer to store read data
696  * @oob_required:	caller expects OOB data read to chip->oob_poi
697  * @page:	page number to read
698  *
699  * This routine is needed for fsmc version 8 as reading from NAND chip has to be
700  * performed in a strict sequence as follows:
701  * data(512 byte) -> ecc(13 byte)
702  * After this read, fsmc hardware generates and reports error data bits(up to a
703  * max of 8 bits)
704  */
705 static int fsmc_read_page_hwecc(struct nand_chip *chip, u8 *buf,
706 				int oob_required, int page)
707 {
708 	struct mtd_info *mtd = nand_to_mtd(chip);
709 	int i, j, s, stat, eccsize = chip->ecc.size;
710 	int eccbytes = chip->ecc.bytes;
711 	int eccsteps = chip->ecc.steps;
712 	u8 *p = buf;
713 	u8 *ecc_calc = chip->ecc.calc_buf;
714 	u8 *ecc_code = chip->ecc.code_buf;
715 	int off, len, ret, group = 0;
716 	/*
717 	 * ecc_oob is intentionally taken as u16. In 16bit devices, we
718 	 * end up reading 14 bytes (7 words) from oob. The local array is
719 	 * to maintain word alignment
720 	 */
721 	u16 ecc_oob[7];
722 	u8 *oob = (u8 *)&ecc_oob[0];
723 	unsigned int max_bitflips = 0;
724 
725 	for (i = 0, s = 0; s < eccsteps; s++, i += eccbytes, p += eccsize) {
726 		nand_read_page_op(chip, page, s * eccsize, NULL, 0);
727 		chip->ecc.hwctl(chip, NAND_ECC_READ);
728 		ret = nand_read_data_op(chip, p, eccsize, false, false);
729 		if (ret)
730 			return ret;
731 
732 		for (j = 0; j < eccbytes;) {
733 			struct mtd_oob_region oobregion;
734 
735 			ret = mtd_ooblayout_ecc(mtd, group++, &oobregion);
736 			if (ret)
737 				return ret;
738 
739 			off = oobregion.offset;
740 			len = oobregion.length;
741 
742 			/*
743 			 * length is intentionally kept a higher multiple of 2
744 			 * to read at least 13 bytes even in case of 16 bit NAND
745 			 * devices
746 			 */
747 			if (chip->options & NAND_BUSWIDTH_16)
748 				len = roundup(len, 2);
749 
750 			nand_read_oob_op(chip, page, off, oob + j, len);
751 			j += len;
752 		}
753 
754 		memcpy(&ecc_code[i], oob, chip->ecc.bytes);
755 		chip->ecc.calculate(chip, p, &ecc_calc[i]);
756 
757 		stat = chip->ecc.correct(chip, p, &ecc_code[i], &ecc_calc[i]);
758 		if (stat < 0) {
759 			mtd->ecc_stats.failed++;
760 		} else {
761 			mtd->ecc_stats.corrected += stat;
762 			max_bitflips = max_t(unsigned int, max_bitflips, stat);
763 		}
764 	}
765 
766 	return max_bitflips;
767 }
768 
769 /*
770  * fsmc_bch8_correct_data
771  * @mtd:	mtd info structure
772  * @dat:	buffer of read data
773  * @read_ecc:	ecc read from device spare area
774  * @calc_ecc:	ecc calculated from read data
775  *
776  * calc_ecc is a 104 bit information containing maximum of 8 error
777  * offset information of 13 bits each in 512 bytes of read data.
778  */
779 static int fsmc_bch8_correct_data(struct nand_chip *chip, u8 *dat,
780 				  u8 *read_ecc, u8 *calc_ecc)
781 {
782 	struct fsmc_nand_data *host = nand_to_fsmc(chip);
783 	u32 err_idx[8];
784 	u32 num_err, i;
785 	u32 ecc1, ecc2, ecc3, ecc4;
786 
787 	num_err = (readl_relaxed(host->regs_va + STS) >> 10) & 0xF;
788 
789 	/* no bit flipping */
790 	if (likely(num_err == 0))
791 		return 0;
792 
793 	/* too many errors */
794 	if (unlikely(num_err > 8)) {
795 		/*
796 		 * This is a temporary erase check. A newly erased page read
797 		 * would result in an ecc error because the oob data is also
798 		 * erased to FF and the calculated ecc for an FF data is not
799 		 * FF..FF.
800 		 * This is a workaround to skip performing correction in case
801 		 * data is FF..FF
802 		 *
803 		 * Logic:
804 		 * For every page, each bit written as 0 is counted until these
805 		 * number of bits are greater than 8 (the maximum correction
806 		 * capability of FSMC for each 512 + 13 bytes)
807 		 */
808 
809 		int bits_ecc = count_written_bits(read_ecc, chip->ecc.bytes, 8);
810 		int bits_data = count_written_bits(dat, chip->ecc.size, 8);
811 
812 		if ((bits_ecc + bits_data) <= 8) {
813 			if (bits_data)
814 				memset(dat, 0xff, chip->ecc.size);
815 			return bits_data;
816 		}
817 
818 		return -EBADMSG;
819 	}
820 
821 	/*
822 	 * ------------------- calc_ecc[] bit wise -----------|--13 bits--|
823 	 * |---idx[7]--|--.....-----|---idx[2]--||---idx[1]--||---idx[0]--|
824 	 *
825 	 * calc_ecc is a 104 bit information containing maximum of 8 error
826 	 * offset information of 13 bits each. calc_ecc is copied into a
827 	 * u64 array and error offset indexes are populated in err_idx
828 	 * array
829 	 */
830 	ecc1 = readl_relaxed(host->regs_va + ECC1);
831 	ecc2 = readl_relaxed(host->regs_va + ECC2);
832 	ecc3 = readl_relaxed(host->regs_va + ECC3);
833 	ecc4 = readl_relaxed(host->regs_va + STS);
834 
835 	err_idx[0] = (ecc1 >> 0) & 0x1FFF;
836 	err_idx[1] = (ecc1 >> 13) & 0x1FFF;
837 	err_idx[2] = (((ecc2 >> 0) & 0x7F) << 6) | ((ecc1 >> 26) & 0x3F);
838 	err_idx[3] = (ecc2 >> 7) & 0x1FFF;
839 	err_idx[4] = (((ecc3 >> 0) & 0x1) << 12) | ((ecc2 >> 20) & 0xFFF);
840 	err_idx[5] = (ecc3 >> 1) & 0x1FFF;
841 	err_idx[6] = (ecc3 >> 14) & 0x1FFF;
842 	err_idx[7] = (((ecc4 >> 16) & 0xFF) << 5) | ((ecc3 >> 27) & 0x1F);
843 
844 	i = 0;
845 	while (num_err--) {
846 		err_idx[i] ^= 3;
847 
848 		if (err_idx[i] < chip->ecc.size * 8) {
849 			int err = err_idx[i];
850 
851 			dat[err >> 3] ^= BIT(err & 7);
852 			i++;
853 		}
854 	}
855 	return i;
856 }
857 
858 static bool filter(struct dma_chan *chan, void *slave)
859 {
860 	chan->private = slave;
861 	return true;
862 }
863 
864 static int fsmc_nand_probe_config_dt(struct platform_device *pdev,
865 				     struct fsmc_nand_data *host,
866 				     struct nand_chip *nand)
867 {
868 	struct device_node *np = pdev->dev.of_node;
869 	u32 val;
870 	int ret;
871 
872 	nand->options = 0;
873 
874 	if (!of_property_read_u32(np, "bank-width", &val)) {
875 		if (val == 2) {
876 			nand->options |= NAND_BUSWIDTH_16;
877 		} else if (val != 1) {
878 			dev_err(&pdev->dev, "invalid bank-width %u\n", val);
879 			return -EINVAL;
880 		}
881 	}
882 
883 	if (of_property_read_bool(np, "nand-skip-bbtscan"))
884 		nand->options |= NAND_SKIP_BBTSCAN;
885 
886 	host->dev_timings = devm_kzalloc(&pdev->dev,
887 					 sizeof(*host->dev_timings),
888 					 GFP_KERNEL);
889 	if (!host->dev_timings)
890 		return -ENOMEM;
891 
892 	ret = of_property_read_u8_array(np, "timings", (u8 *)host->dev_timings,
893 					sizeof(*host->dev_timings));
894 	if (ret)
895 		host->dev_timings = NULL;
896 
897 	/* Set default NAND bank to 0 */
898 	host->bank = 0;
899 	if (!of_property_read_u32(np, "bank", &val)) {
900 		if (val > 3) {
901 			dev_err(&pdev->dev, "invalid bank %u\n", val);
902 			return -EINVAL;
903 		}
904 		host->bank = val;
905 	}
906 	return 0;
907 }
908 
909 static int fsmc_nand_attach_chip(struct nand_chip *nand)
910 {
911 	struct mtd_info *mtd = nand_to_mtd(nand);
912 	struct fsmc_nand_data *host = nand_to_fsmc(nand);
913 
914 	if (nand->ecc.engine_type == NAND_ECC_ENGINE_TYPE_INVALID)
915 		nand->ecc.engine_type = NAND_ECC_ENGINE_TYPE_ON_HOST;
916 
917 	if (!nand->ecc.size)
918 		nand->ecc.size = 512;
919 
920 	if (AMBA_REV_BITS(host->pid) >= 8) {
921 		nand->ecc.read_page = fsmc_read_page_hwecc;
922 		nand->ecc.calculate = fsmc_read_hwecc_ecc4;
923 		nand->ecc.correct = fsmc_bch8_correct_data;
924 		nand->ecc.bytes = 13;
925 		nand->ecc.strength = 8;
926 	}
927 
928 	if (AMBA_REV_BITS(host->pid) >= 8) {
929 		switch (mtd->oobsize) {
930 		case 16:
931 		case 64:
932 		case 128:
933 		case 224:
934 		case 256:
935 			break;
936 		default:
937 			dev_warn(host->dev,
938 				 "No oob scheme defined for oobsize %d\n",
939 				 mtd->oobsize);
940 			return -EINVAL;
941 		}
942 
943 		mtd_set_ooblayout(mtd, &fsmc_ecc4_ooblayout_ops);
944 
945 		return 0;
946 	}
947 
948 	switch (nand->ecc.engine_type) {
949 	case NAND_ECC_ENGINE_TYPE_ON_HOST:
950 		dev_info(host->dev, "Using 1-bit HW ECC scheme\n");
951 		nand->ecc.calculate = fsmc_read_hwecc_ecc1;
952 		nand->ecc.correct = fsmc_correct_ecc1;
953 		nand->ecc.hwctl = fsmc_enable_hwecc;
954 		nand->ecc.bytes = 3;
955 		nand->ecc.strength = 1;
956 		nand->ecc.options |= NAND_ECC_SOFT_HAMMING_SM_ORDER;
957 		break;
958 
959 	case NAND_ECC_ENGINE_TYPE_SOFT:
960 		if (nand->ecc.algo == NAND_ECC_ALGO_BCH) {
961 			dev_info(host->dev,
962 				 "Using 4-bit SW BCH ECC scheme\n");
963 			break;
964 		}
965 		break;
966 
967 	case NAND_ECC_ENGINE_TYPE_ON_DIE:
968 		break;
969 
970 	default:
971 		dev_err(host->dev, "Unsupported ECC mode!\n");
972 		return -ENOTSUPP;
973 	}
974 
975 	/*
976 	 * Don't set layout for BCH4 SW ECC. This will be
977 	 * generated later during BCH initialization.
978 	 */
979 	if (nand->ecc.engine_type == NAND_ECC_ENGINE_TYPE_ON_HOST) {
980 		switch (mtd->oobsize) {
981 		case 16:
982 		case 64:
983 		case 128:
984 			mtd_set_ooblayout(mtd,
985 					  &fsmc_ecc1_ooblayout_ops);
986 			break;
987 		default:
988 			dev_warn(host->dev,
989 				 "No oob scheme defined for oobsize %d\n",
990 				 mtd->oobsize);
991 			return -EINVAL;
992 		}
993 	}
994 
995 	return 0;
996 }
997 
998 static const struct nand_controller_ops fsmc_nand_controller_ops = {
999 	.attach_chip = fsmc_nand_attach_chip,
1000 	.exec_op = fsmc_exec_op,
1001 	.setup_interface = fsmc_setup_interface,
1002 };
1003 
1004 /**
1005  * fsmc_nand_disable() - Disables the NAND bank
1006  * @host: The instance to disable
1007  */
1008 static void fsmc_nand_disable(struct fsmc_nand_data *host)
1009 {
1010 	u32 val;
1011 
1012 	val = readl(host->regs_va + FSMC_PC);
1013 	val &= ~FSMC_ENABLE;
1014 	writel(val, host->regs_va + FSMC_PC);
1015 }
1016 
1017 /*
1018  * fsmc_nand_probe - Probe function
1019  * @pdev:       platform device structure
1020  */
1021 static int __init fsmc_nand_probe(struct platform_device *pdev)
1022 {
1023 	struct fsmc_nand_data *host;
1024 	struct mtd_info *mtd;
1025 	struct nand_chip *nand;
1026 	struct resource *res;
1027 	void __iomem *base;
1028 	dma_cap_mask_t mask;
1029 	int ret = 0;
1030 	u32 pid;
1031 	int i;
1032 
1033 	/* Allocate memory for the device structure (and zero it) */
1034 	host = devm_kzalloc(&pdev->dev, sizeof(*host), GFP_KERNEL);
1035 	if (!host)
1036 		return -ENOMEM;
1037 
1038 	nand = &host->nand;
1039 
1040 	ret = fsmc_nand_probe_config_dt(pdev, host, nand);
1041 	if (ret)
1042 		return ret;
1043 
1044 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "nand_data");
1045 	host->data_va = devm_ioremap_resource(&pdev->dev, res);
1046 	if (IS_ERR(host->data_va))
1047 		return PTR_ERR(host->data_va);
1048 
1049 	host->data_pa = (dma_addr_t)res->start;
1050 
1051 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "nand_addr");
1052 	host->addr_va = devm_ioremap_resource(&pdev->dev, res);
1053 	if (IS_ERR(host->addr_va))
1054 		return PTR_ERR(host->addr_va);
1055 
1056 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "nand_cmd");
1057 	host->cmd_va = devm_ioremap_resource(&pdev->dev, res);
1058 	if (IS_ERR(host->cmd_va))
1059 		return PTR_ERR(host->cmd_va);
1060 
1061 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "fsmc_regs");
1062 	base = devm_ioremap_resource(&pdev->dev, res);
1063 	if (IS_ERR(base))
1064 		return PTR_ERR(base);
1065 
1066 	host->regs_va = base + FSMC_NOR_REG_SIZE +
1067 		(host->bank * FSMC_NAND_BANK_SZ);
1068 
1069 	host->clk = devm_clk_get(&pdev->dev, NULL);
1070 	if (IS_ERR(host->clk)) {
1071 		dev_err(&pdev->dev, "failed to fetch block clock\n");
1072 		return PTR_ERR(host->clk);
1073 	}
1074 
1075 	ret = clk_prepare_enable(host->clk);
1076 	if (ret)
1077 		return ret;
1078 
1079 	/*
1080 	 * This device ID is actually a common AMBA ID as used on the
1081 	 * AMBA PrimeCell bus. However it is not a PrimeCell.
1082 	 */
1083 	for (pid = 0, i = 0; i < 4; i++)
1084 		pid |= (readl(base + resource_size(res) - 0x20 + 4 * i) &
1085 			255) << (i * 8);
1086 
1087 	host->pid = pid;
1088 
1089 	dev_info(&pdev->dev,
1090 		 "FSMC device partno %03x, manufacturer %02x, revision %02x, config %02x\n",
1091 		 AMBA_PART_BITS(pid), AMBA_MANF_BITS(pid),
1092 		 AMBA_REV_BITS(pid), AMBA_CONFIG_BITS(pid));
1093 
1094 	host->dev = &pdev->dev;
1095 
1096 	if (host->mode == USE_DMA_ACCESS)
1097 		init_completion(&host->dma_access_complete);
1098 
1099 	/* Link all private pointers */
1100 	mtd = nand_to_mtd(&host->nand);
1101 	nand_set_flash_node(nand, pdev->dev.of_node);
1102 
1103 	mtd->dev.parent = &pdev->dev;
1104 
1105 	nand->badblockbits = 7;
1106 
1107 	if (host->mode == USE_DMA_ACCESS) {
1108 		dma_cap_zero(mask);
1109 		dma_cap_set(DMA_MEMCPY, mask);
1110 		host->read_dma_chan = dma_request_channel(mask, filter, NULL);
1111 		if (!host->read_dma_chan) {
1112 			dev_err(&pdev->dev, "Unable to get read dma channel\n");
1113 			ret = -ENODEV;
1114 			goto disable_clk;
1115 		}
1116 		host->write_dma_chan = dma_request_channel(mask, filter, NULL);
1117 		if (!host->write_dma_chan) {
1118 			dev_err(&pdev->dev, "Unable to get write dma channel\n");
1119 			ret = -ENODEV;
1120 			goto release_dma_read_chan;
1121 		}
1122 	}
1123 
1124 	if (host->dev_timings) {
1125 		fsmc_nand_setup(host, host->dev_timings);
1126 		nand->options |= NAND_KEEP_TIMINGS;
1127 	}
1128 
1129 	nand_controller_init(&host->base);
1130 	host->base.ops = &fsmc_nand_controller_ops;
1131 	nand->controller = &host->base;
1132 
1133 	/*
1134 	 * Scan to find existence of the device
1135 	 */
1136 	ret = nand_scan(nand, 1);
1137 	if (ret)
1138 		goto release_dma_write_chan;
1139 
1140 	mtd->name = "nand";
1141 	ret = mtd_device_register(mtd, NULL, 0);
1142 	if (ret)
1143 		goto cleanup_nand;
1144 
1145 	platform_set_drvdata(pdev, host);
1146 	dev_info(&pdev->dev, "FSMC NAND driver registration successful\n");
1147 
1148 	return 0;
1149 
1150 cleanup_nand:
1151 	nand_cleanup(nand);
1152 release_dma_write_chan:
1153 	if (host->mode == USE_DMA_ACCESS)
1154 		dma_release_channel(host->write_dma_chan);
1155 release_dma_read_chan:
1156 	if (host->mode == USE_DMA_ACCESS)
1157 		dma_release_channel(host->read_dma_chan);
1158 disable_clk:
1159 	fsmc_nand_disable(host);
1160 	clk_disable_unprepare(host->clk);
1161 
1162 	return ret;
1163 }
1164 
1165 /*
1166  * Clean up routine
1167  */
1168 static void fsmc_nand_remove(struct platform_device *pdev)
1169 {
1170 	struct fsmc_nand_data *host = platform_get_drvdata(pdev);
1171 
1172 	if (host) {
1173 		struct nand_chip *chip = &host->nand;
1174 		int ret;
1175 
1176 		ret = mtd_device_unregister(nand_to_mtd(chip));
1177 		WARN_ON(ret);
1178 		nand_cleanup(chip);
1179 		fsmc_nand_disable(host);
1180 
1181 		if (host->mode == USE_DMA_ACCESS) {
1182 			dma_release_channel(host->write_dma_chan);
1183 			dma_release_channel(host->read_dma_chan);
1184 		}
1185 		clk_disable_unprepare(host->clk);
1186 	}
1187 }
1188 
1189 #ifdef CONFIG_PM_SLEEP
1190 static int fsmc_nand_suspend(struct device *dev)
1191 {
1192 	struct fsmc_nand_data *host = dev_get_drvdata(dev);
1193 
1194 	if (host)
1195 		clk_disable_unprepare(host->clk);
1196 
1197 	return 0;
1198 }
1199 
1200 static int fsmc_nand_resume(struct device *dev)
1201 {
1202 	struct fsmc_nand_data *host = dev_get_drvdata(dev);
1203 
1204 	if (host) {
1205 		clk_prepare_enable(host->clk);
1206 		if (host->dev_timings)
1207 			fsmc_nand_setup(host, host->dev_timings);
1208 		nand_reset(&host->nand, 0);
1209 	}
1210 
1211 	return 0;
1212 }
1213 #endif
1214 
1215 static SIMPLE_DEV_PM_OPS(fsmc_nand_pm_ops, fsmc_nand_suspend, fsmc_nand_resume);
1216 
1217 static const struct of_device_id fsmc_nand_id_table[] = {
1218 	{ .compatible = "st,spear600-fsmc-nand" },
1219 	{ .compatible = "stericsson,fsmc-nand" },
1220 	{}
1221 };
1222 MODULE_DEVICE_TABLE(of, fsmc_nand_id_table);
1223 
1224 static struct platform_driver fsmc_nand_driver = {
1225 	.remove_new = fsmc_nand_remove,
1226 	.driver = {
1227 		.name = "fsmc-nand",
1228 		.of_match_table = fsmc_nand_id_table,
1229 		.pm = &fsmc_nand_pm_ops,
1230 	},
1231 };
1232 
1233 module_platform_driver_probe(fsmc_nand_driver, fsmc_nand_probe);
1234 
1235 MODULE_LICENSE("GPL v2");
1236 MODULE_AUTHOR("Vipin Kumar <vipin.kumar@st.com>, Ashish Priyadarshi");
1237 MODULE_DESCRIPTION("NAND driver for SPEAr Platforms");
1238