1/*
2 * davinci_nand.c - NAND Flash Driver for DaVinci family chips
3 *
4 * Copyright © 2006 Texas Instruments.
5 *
6 * Port to 2.6.23 Copyright © 2008 by:
7 *   Sander Huijsen <Shuijsen@optelecom-nkf.com>
8 *   Troy Kisky <troy.kisky@boundarydevices.com>
9 *   Dirk Behme <Dirk.Behme@gmail.com>
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19 * GNU General Public License for more details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 */
25
26#include <linux/kernel.h>
27#include <linux/module.h>
28#include <linux/platform_device.h>
29#include <linux/err.h>
30#include <linux/clk.h>
31#include <linux/io.h>
32#include <linux/mtd/nand.h>
33#include <linux/mtd/partitions.h>
34#include <linux/slab.h>
35#include <linux/of_device.h>
36#include <linux/of.h>
37#include <linux/of_mtd.h>
38
39#include <linux/platform_data/mtd-davinci.h>
40#include <linux/platform_data/mtd-davinci-aemif.h>
41
42/*
43 * This is a device driver for the NAND flash controller found on the
44 * various DaVinci family chips.  It handles up to four SoC chipselects,
45 * and some flavors of secondary chipselect (e.g. based on A12) as used
46 * with multichip packages.
47 *
48 * The 1-bit ECC hardware is supported, as well as the newer 4-bit ECC
49 * available on chips like the DM355 and OMAP-L137 and needed with the
50 * more error-prone MLC NAND chips.
51 *
52 * This driver assumes EM_WAIT connects all the NAND devices' RDY/nBUSY
53 * outputs in a "wire-AND" configuration, with no per-chip signals.
54 */
55struct davinci_nand_info {
56	struct mtd_info		mtd;
57	struct nand_chip	chip;
58	struct nand_ecclayout	ecclayout;
59
60	struct device		*dev;
61	struct clk		*clk;
62
63	bool			is_readmode;
64
65	void __iomem		*base;
66	void __iomem		*vaddr;
67
68	uint32_t		ioaddr;
69	uint32_t		current_cs;
70
71	uint32_t		mask_chipsel;
72	uint32_t		mask_ale;
73	uint32_t		mask_cle;
74
75	uint32_t		core_chipsel;
76
77	struct davinci_aemif_timing	*timing;
78};
79
80static DEFINE_SPINLOCK(davinci_nand_lock);
81static bool ecc4_busy;
82
83#define to_davinci_nand(m) container_of(m, struct davinci_nand_info, mtd)
84
85
86static inline unsigned int davinci_nand_readl(struct davinci_nand_info *info,
87		int offset)
88{
89	return __raw_readl(info->base + offset);
90}
91
92static inline void davinci_nand_writel(struct davinci_nand_info *info,
93		int offset, unsigned long value)
94{
95	__raw_writel(value, info->base + offset);
96}
97
98/*----------------------------------------------------------------------*/
99
100/*
101 * Access to hardware control lines:  ALE, CLE, secondary chipselect.
102 */
103
104static void nand_davinci_hwcontrol(struct mtd_info *mtd, int cmd,
105				   unsigned int ctrl)
106{
107	struct davinci_nand_info	*info = to_davinci_nand(mtd);
108	uint32_t			addr = info->current_cs;
109	struct nand_chip		*nand = mtd->priv;
110
111	/* Did the control lines change? */
112	if (ctrl & NAND_CTRL_CHANGE) {
113		if ((ctrl & NAND_CTRL_CLE) == NAND_CTRL_CLE)
114			addr |= info->mask_cle;
115		else if ((ctrl & NAND_CTRL_ALE) == NAND_CTRL_ALE)
116			addr |= info->mask_ale;
117
118		nand->IO_ADDR_W = (void __iomem __force *)addr;
119	}
120
121	if (cmd != NAND_CMD_NONE)
122		iowrite8(cmd, nand->IO_ADDR_W);
123}
124
125static void nand_davinci_select_chip(struct mtd_info *mtd, int chip)
126{
127	struct davinci_nand_info	*info = to_davinci_nand(mtd);
128	uint32_t			addr = info->ioaddr;
129
130	/* maybe kick in a second chipselect */
131	if (chip > 0)
132		addr |= info->mask_chipsel;
133	info->current_cs = addr;
134
135	info->chip.IO_ADDR_W = (void __iomem __force *)addr;
136	info->chip.IO_ADDR_R = info->chip.IO_ADDR_W;
137}
138
139/*----------------------------------------------------------------------*/
140
141/*
142 * 1-bit hardware ECC ... context maintained for each core chipselect
143 */
144
145static inline uint32_t nand_davinci_readecc_1bit(struct mtd_info *mtd)
146{
147	struct davinci_nand_info *info = to_davinci_nand(mtd);
148
149	return davinci_nand_readl(info, NANDF1ECC_OFFSET
150			+ 4 * info->core_chipsel);
151}
152
153static void nand_davinci_hwctl_1bit(struct mtd_info *mtd, int mode)
154{
155	struct davinci_nand_info *info;
156	uint32_t nandcfr;
157	unsigned long flags;
158
159	info = to_davinci_nand(mtd);
160
161	/* Reset ECC hardware */
162	nand_davinci_readecc_1bit(mtd);
163
164	spin_lock_irqsave(&davinci_nand_lock, flags);
165
166	/* Restart ECC hardware */
167	nandcfr = davinci_nand_readl(info, NANDFCR_OFFSET);
168	nandcfr |= BIT(8 + info->core_chipsel);
169	davinci_nand_writel(info, NANDFCR_OFFSET, nandcfr);
170
171	spin_unlock_irqrestore(&davinci_nand_lock, flags);
172}
173
174/*
175 * Read hardware ECC value and pack into three bytes
176 */
177static int nand_davinci_calculate_1bit(struct mtd_info *mtd,
178				      const u_char *dat, u_char *ecc_code)
179{
180	unsigned int ecc_val = nand_davinci_readecc_1bit(mtd);
181	unsigned int ecc24 = (ecc_val & 0x0fff) | ((ecc_val & 0x0fff0000) >> 4);
182
183	/* invert so that erased block ecc is correct */
184	ecc24 = ~ecc24;
185	ecc_code[0] = (u_char)(ecc24);
186	ecc_code[1] = (u_char)(ecc24 >> 8);
187	ecc_code[2] = (u_char)(ecc24 >> 16);
188
189	return 0;
190}
191
192static int nand_davinci_correct_1bit(struct mtd_info *mtd, u_char *dat,
193				     u_char *read_ecc, u_char *calc_ecc)
194{
195	struct nand_chip *chip = mtd->priv;
196	uint32_t eccNand = read_ecc[0] | (read_ecc[1] << 8) |
197					  (read_ecc[2] << 16);
198	uint32_t eccCalc = calc_ecc[0] | (calc_ecc[1] << 8) |
199					  (calc_ecc[2] << 16);
200	uint32_t diff = eccCalc ^ eccNand;
201
202	if (diff) {
203		if ((((diff >> 12) ^ diff) & 0xfff) == 0xfff) {
204			/* Correctable error */
205			if ((diff >> (12 + 3)) < chip->ecc.size) {
206				dat[diff >> (12 + 3)] ^= BIT((diff >> 12) & 7);
207				return 1;
208			} else {
209				return -1;
210			}
211		} else if (!(diff & (diff - 1))) {
212			/* Single bit ECC error in the ECC itself,
213			 * nothing to fix */
214			return 1;
215		} else {
216			/* Uncorrectable error */
217			return -1;
218		}
219
220	}
221	return 0;
222}
223
224/*----------------------------------------------------------------------*/
225
226/*
227 * 4-bit hardware ECC ... context maintained over entire AEMIF
228 *
229 * This is a syndrome engine, but we avoid NAND_ECC_HW_SYNDROME
230 * since that forces use of a problematic "infix OOB" layout.
231 * Among other things, it trashes manufacturer bad block markers.
232 * Also, and specific to this hardware, it ECC-protects the "prepad"
233 * in the OOB ... while having ECC protection for parts of OOB would
234 * seem useful, the current MTD stack sometimes wants to update the
235 * OOB without recomputing ECC.
236 */
237
238static void nand_davinci_hwctl_4bit(struct mtd_info *mtd, int mode)
239{
240	struct davinci_nand_info *info = to_davinci_nand(mtd);
241	unsigned long flags;
242	u32 val;
243
244	spin_lock_irqsave(&davinci_nand_lock, flags);
245
246	/* Start 4-bit ECC calculation for read/write */
247	val = davinci_nand_readl(info, NANDFCR_OFFSET);
248	val &= ~(0x03 << 4);
249	val |= (info->core_chipsel << 4) | BIT(12);
250	davinci_nand_writel(info, NANDFCR_OFFSET, val);
251
252	info->is_readmode = (mode == NAND_ECC_READ);
253
254	spin_unlock_irqrestore(&davinci_nand_lock, flags);
255}
256
257/* Read raw ECC code after writing to NAND. */
258static void
259nand_davinci_readecc_4bit(struct davinci_nand_info *info, u32 code[4])
260{
261	const u32 mask = 0x03ff03ff;
262
263	code[0] = davinci_nand_readl(info, NAND_4BIT_ECC1_OFFSET) & mask;
264	code[1] = davinci_nand_readl(info, NAND_4BIT_ECC2_OFFSET) & mask;
265	code[2] = davinci_nand_readl(info, NAND_4BIT_ECC3_OFFSET) & mask;
266	code[3] = davinci_nand_readl(info, NAND_4BIT_ECC4_OFFSET) & mask;
267}
268
269/* Terminate read ECC; or return ECC (as bytes) of data written to NAND. */
270static int nand_davinci_calculate_4bit(struct mtd_info *mtd,
271		const u_char *dat, u_char *ecc_code)
272{
273	struct davinci_nand_info *info = to_davinci_nand(mtd);
274	u32 raw_ecc[4], *p;
275	unsigned i;
276
277	/* After a read, terminate ECC calculation by a dummy read
278	 * of some 4-bit ECC register.  ECC covers everything that
279	 * was read; correct() just uses the hardware state, so
280	 * ecc_code is not needed.
281	 */
282	if (info->is_readmode) {
283		davinci_nand_readl(info, NAND_4BIT_ECC1_OFFSET);
284		return 0;
285	}
286
287	/* Pack eight raw 10-bit ecc values into ten bytes, making
288	 * two passes which each convert four values (in upper and
289	 * lower halves of two 32-bit words) into five bytes.  The
290	 * ROM boot loader uses this same packing scheme.
291	 */
292	nand_davinci_readecc_4bit(info, raw_ecc);
293	for (i = 0, p = raw_ecc; i < 2; i++, p += 2) {
294		*ecc_code++ =   p[0]        & 0xff;
295		*ecc_code++ = ((p[0] >>  8) & 0x03) | ((p[0] >> 14) & 0xfc);
296		*ecc_code++ = ((p[0] >> 22) & 0x0f) | ((p[1] <<  4) & 0xf0);
297		*ecc_code++ = ((p[1] >>  4) & 0x3f) | ((p[1] >> 10) & 0xc0);
298		*ecc_code++ =  (p[1] >> 18) & 0xff;
299	}
300
301	return 0;
302}
303
304/* Correct up to 4 bits in data we just read, using state left in the
305 * hardware plus the ecc_code computed when it was first written.
306 */
307static int nand_davinci_correct_4bit(struct mtd_info *mtd,
308		u_char *data, u_char *ecc_code, u_char *null)
309{
310	int i;
311	struct davinci_nand_info *info = to_davinci_nand(mtd);
312	unsigned short ecc10[8];
313	unsigned short *ecc16;
314	u32 syndrome[4];
315	u32 ecc_state;
316	unsigned num_errors, corrected;
317	unsigned long timeo;
318
319	/* All bytes 0xff?  It's an erased page; ignore its ECC. */
320	for (i = 0; i < 10; i++) {
321		if (ecc_code[i] != 0xff)
322			goto compare;
323	}
324	return 0;
325
326compare:
327	/* Unpack ten bytes into eight 10 bit values.  We know we're
328	 * little-endian, and use type punning for less shifting/masking.
329	 */
330	if (WARN_ON(0x01 & (unsigned) ecc_code))
331		return -EINVAL;
332	ecc16 = (unsigned short *)ecc_code;
333
334	ecc10[0] =  (ecc16[0] >>  0) & 0x3ff;
335	ecc10[1] = ((ecc16[0] >> 10) & 0x3f) | ((ecc16[1] << 6) & 0x3c0);
336	ecc10[2] =  (ecc16[1] >>  4) & 0x3ff;
337	ecc10[3] = ((ecc16[1] >> 14) & 0x3)  | ((ecc16[2] << 2) & 0x3fc);
338	ecc10[4] =  (ecc16[2] >>  8)         | ((ecc16[3] << 8) & 0x300);
339	ecc10[5] =  (ecc16[3] >>  2) & 0x3ff;
340	ecc10[6] = ((ecc16[3] >> 12) & 0xf)  | ((ecc16[4] << 4) & 0x3f0);
341	ecc10[7] =  (ecc16[4] >>  6) & 0x3ff;
342
343	/* Tell ECC controller about the expected ECC codes. */
344	for (i = 7; i >= 0; i--)
345		davinci_nand_writel(info, NAND_4BIT_ECC_LOAD_OFFSET, ecc10[i]);
346
347	/* Allow time for syndrome calculation ... then read it.
348	 * A syndrome of all zeroes 0 means no detected errors.
349	 */
350	davinci_nand_readl(info, NANDFSR_OFFSET);
351	nand_davinci_readecc_4bit(info, syndrome);
352	if (!(syndrome[0] | syndrome[1] | syndrome[2] | syndrome[3]))
353		return 0;
354
355	/*
356	 * Clear any previous address calculation by doing a dummy read of an
357	 * error address register.
358	 */
359	davinci_nand_readl(info, NAND_ERR_ADD1_OFFSET);
360
361	/* Start address calculation, and wait for it to complete.
362	 * We _could_ start reading more data while this is working,
363	 * to speed up the overall page read.
364	 */
365	davinci_nand_writel(info, NANDFCR_OFFSET,
366			davinci_nand_readl(info, NANDFCR_OFFSET) | BIT(13));
367
368	/*
369	 * ECC_STATE field reads 0x3 (Error correction complete) immediately
370	 * after setting the 4BITECC_ADD_CALC_START bit. So if you immediately
371	 * begin trying to poll for the state, you may fall right out of your
372	 * loop without any of the correction calculations having taken place.
373	 * The recommendation from the hardware team is to initially delay as
374	 * long as ECC_STATE reads less than 4. After that, ECC HW has entered
375	 * correction state.
376	 */
377	timeo = jiffies + usecs_to_jiffies(100);
378	do {
379		ecc_state = (davinci_nand_readl(info,
380				NANDFSR_OFFSET) >> 8) & 0x0f;
381		cpu_relax();
382	} while ((ecc_state < 4) && time_before(jiffies, timeo));
383
384	for (;;) {
385		u32	fsr = davinci_nand_readl(info, NANDFSR_OFFSET);
386
387		switch ((fsr >> 8) & 0x0f) {
388		case 0:		/* no error, should not happen */
389			davinci_nand_readl(info, NAND_ERR_ERRVAL1_OFFSET);
390			return 0;
391		case 1:		/* five or more errors detected */
392			davinci_nand_readl(info, NAND_ERR_ERRVAL1_OFFSET);
393			return -EIO;
394		case 2:		/* error addresses computed */
395		case 3:
396			num_errors = 1 + ((fsr >> 16) & 0x03);
397			goto correct;
398		default:	/* still working on it */
399			cpu_relax();
400			continue;
401		}
402	}
403
404correct:
405	/* correct each error */
406	for (i = 0, corrected = 0; i < num_errors; i++) {
407		int error_address, error_value;
408
409		if (i > 1) {
410			error_address = davinci_nand_readl(info,
411						NAND_ERR_ADD2_OFFSET);
412			error_value = davinci_nand_readl(info,
413						NAND_ERR_ERRVAL2_OFFSET);
414		} else {
415			error_address = davinci_nand_readl(info,
416						NAND_ERR_ADD1_OFFSET);
417			error_value = davinci_nand_readl(info,
418						NAND_ERR_ERRVAL1_OFFSET);
419		}
420
421		if (i & 1) {
422			error_address >>= 16;
423			error_value >>= 16;
424		}
425		error_address &= 0x3ff;
426		error_address = (512 + 7) - error_address;
427
428		if (error_address < 512) {
429			data[error_address] ^= error_value;
430			corrected++;
431		}
432	}
433
434	return corrected;
435}
436
437/*----------------------------------------------------------------------*/
438
439/*
440 * NOTE:  NAND boot requires ALE == EM_A[1], CLE == EM_A[2], so that's
441 * how these chips are normally wired.  This translates to both 8 and 16
442 * bit busses using ALE == BIT(3) in byte addresses, and CLE == BIT(4).
443 *
444 * For now we assume that configuration, or any other one which ignores
445 * the two LSBs for NAND access ... so we can issue 32-bit reads/writes
446 * and have that transparently morphed into multiple NAND operations.
447 */
448static void nand_davinci_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
449{
450	struct nand_chip *chip = mtd->priv;
451
452	if ((0x03 & ((unsigned)buf)) == 0 && (0x03 & len) == 0)
453		ioread32_rep(chip->IO_ADDR_R, buf, len >> 2);
454	else if ((0x01 & ((unsigned)buf)) == 0 && (0x01 & len) == 0)
455		ioread16_rep(chip->IO_ADDR_R, buf, len >> 1);
456	else
457		ioread8_rep(chip->IO_ADDR_R, buf, len);
458}
459
460static void nand_davinci_write_buf(struct mtd_info *mtd,
461		const uint8_t *buf, int len)
462{
463	struct nand_chip *chip = mtd->priv;
464
465	if ((0x03 & ((unsigned)buf)) == 0 && (0x03 & len) == 0)
466		iowrite32_rep(chip->IO_ADDR_R, buf, len >> 2);
467	else if ((0x01 & ((unsigned)buf)) == 0 && (0x01 & len) == 0)
468		iowrite16_rep(chip->IO_ADDR_R, buf, len >> 1);
469	else
470		iowrite8_rep(chip->IO_ADDR_R, buf, len);
471}
472
473/*
474 * Check hardware register for wait status. Returns 1 if device is ready,
475 * 0 if it is still busy.
476 */
477static int nand_davinci_dev_ready(struct mtd_info *mtd)
478{
479	struct davinci_nand_info *info = to_davinci_nand(mtd);
480
481	return davinci_nand_readl(info, NANDFSR_OFFSET) & BIT(0);
482}
483
484/*----------------------------------------------------------------------*/
485
486/* An ECC layout for using 4-bit ECC with small-page flash, storing
487 * ten ECC bytes plus the manufacturer's bad block marker byte, and
488 * and not overlapping the default BBT markers.
489 */
490static struct nand_ecclayout hwecc4_small = {
491	.eccbytes = 10,
492	.eccpos = { 0, 1, 2, 3, 4,
493		/* offset 5 holds the badblock marker */
494		6, 7,
495		13, 14, 15, },
496	.oobfree = {
497		{.offset = 8, .length = 5, },
498		{.offset = 16, },
499	},
500};
501
502/* An ECC layout for using 4-bit ECC with large-page (2048bytes) flash,
503 * storing ten ECC bytes plus the manufacturer's bad block marker byte,
504 * and not overlapping the default BBT markers.
505 */
506static struct nand_ecclayout hwecc4_2048 = {
507	.eccbytes = 40,
508	.eccpos = {
509		/* at the end of spare sector */
510		24, 25, 26, 27, 28, 29,	30, 31, 32, 33,
511		34, 35, 36, 37, 38, 39,	40, 41, 42, 43,
512		44, 45, 46, 47, 48, 49, 50, 51, 52, 53,
513		54, 55, 56, 57, 58, 59, 60, 61, 62, 63,
514		},
515	.oobfree = {
516		/* 2 bytes at offset 0 hold manufacturer badblock markers */
517		{.offset = 2, .length = 22, },
518		/* 5 bytes at offset 8 hold BBT markers */
519		/* 8 bytes at offset 16 hold JFFS2 clean markers */
520	},
521};
522
523#if defined(CONFIG_OF)
524static const struct of_device_id davinci_nand_of_match[] = {
525	{.compatible = "ti,davinci-nand", },
526	{.compatible = "ti,keystone-nand", },
527	{},
528};
529MODULE_DEVICE_TABLE(of, davinci_nand_of_match);
530
531static struct davinci_nand_pdata
532	*nand_davinci_get_pdata(struct platform_device *pdev)
533{
534	if (!dev_get_platdata(&pdev->dev) && pdev->dev.of_node) {
535		struct davinci_nand_pdata *pdata;
536		const char *mode;
537		u32 prop;
538
539		pdata =  devm_kzalloc(&pdev->dev,
540				sizeof(struct davinci_nand_pdata),
541				GFP_KERNEL);
542		pdev->dev.platform_data = pdata;
543		if (!pdata)
544			return ERR_PTR(-ENOMEM);
545		if (!of_property_read_u32(pdev->dev.of_node,
546			"ti,davinci-chipselect", &prop))
547			pdev->id = prop;
548		else
549			return ERR_PTR(-EINVAL);
550
551		if (!of_property_read_u32(pdev->dev.of_node,
552			"ti,davinci-mask-ale", &prop))
553			pdata->mask_ale = prop;
554		if (!of_property_read_u32(pdev->dev.of_node,
555			"ti,davinci-mask-cle", &prop))
556			pdata->mask_cle = prop;
557		if (!of_property_read_u32(pdev->dev.of_node,
558			"ti,davinci-mask-chipsel", &prop))
559			pdata->mask_chipsel = prop;
560		if (!of_property_read_string(pdev->dev.of_node,
561			"nand-ecc-mode", &mode) ||
562		    !of_property_read_string(pdev->dev.of_node,
563			"ti,davinci-ecc-mode", &mode)) {
564			if (!strncmp("none", mode, 4))
565				pdata->ecc_mode = NAND_ECC_NONE;
566			if (!strncmp("soft", mode, 4))
567				pdata->ecc_mode = NAND_ECC_SOFT;
568			if (!strncmp("hw", mode, 2))
569				pdata->ecc_mode = NAND_ECC_HW;
570		}
571		if (!of_property_read_u32(pdev->dev.of_node,
572			"ti,davinci-ecc-bits", &prop))
573			pdata->ecc_bits = prop;
574
575		prop = of_get_nand_bus_width(pdev->dev.of_node);
576		if (0 < prop || !of_property_read_u32(pdev->dev.of_node,
577			"ti,davinci-nand-buswidth", &prop))
578			if (prop == 16)
579				pdata->options |= NAND_BUSWIDTH_16;
580		if (of_property_read_bool(pdev->dev.of_node,
581			"nand-on-flash-bbt") ||
582		    of_property_read_bool(pdev->dev.of_node,
583			"ti,davinci-nand-use-bbt"))
584			pdata->bbt_options = NAND_BBT_USE_FLASH;
585
586		if (of_device_is_compatible(pdev->dev.of_node,
587					    "ti,keystone-nand")) {
588			pdata->options |= NAND_NO_SUBPAGE_WRITE;
589		}
590	}
591
592	return dev_get_platdata(&pdev->dev);
593}
594#else
595static struct davinci_nand_pdata
596	*nand_davinci_get_pdata(struct platform_device *pdev)
597{
598	return dev_get_platdata(&pdev->dev);
599}
600#endif
601
602static int nand_davinci_probe(struct platform_device *pdev)
603{
604	struct davinci_nand_pdata	*pdata;
605	struct davinci_nand_info	*info;
606	struct resource			*res1;
607	struct resource			*res2;
608	void __iomem			*vaddr;
609	void __iomem			*base;
610	int				ret;
611	uint32_t			val;
612	nand_ecc_modes_t		ecc_mode;
613
614	pdata = nand_davinci_get_pdata(pdev);
615	if (IS_ERR(pdata))
616		return PTR_ERR(pdata);
617
618	/* insist on board-specific configuration */
619	if (!pdata)
620		return -ENODEV;
621
622	/* which external chipselect will we be managing? */
623	if (pdev->id < 0 || pdev->id > 3)
624		return -ENODEV;
625
626	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
627	if (!info)
628		return -ENOMEM;
629
630	platform_set_drvdata(pdev, info);
631
632	res1 = platform_get_resource(pdev, IORESOURCE_MEM, 0);
633	res2 = platform_get_resource(pdev, IORESOURCE_MEM, 1);
634	if (!res1 || !res2) {
635		dev_err(&pdev->dev, "resource missing\n");
636		return -EINVAL;
637	}
638
639	vaddr = devm_ioremap_resource(&pdev->dev, res1);
640	if (IS_ERR(vaddr))
641		return PTR_ERR(vaddr);
642
643	/*
644	 * This registers range is used to setup NAND settings. In case with
645	 * TI AEMIF driver, the same memory address range is requested already
646	 * by AEMIF, so we cannot request it twice, just ioremap.
647	 * The AEMIF and NAND drivers not use the same registers in this range.
648	 */
649	base = devm_ioremap(&pdev->dev, res2->start, resource_size(res2));
650	if (!base) {
651		dev_err(&pdev->dev, "ioremap failed for resource %pR\n", res2);
652		return -EADDRNOTAVAIL;
653	}
654
655	info->dev		= &pdev->dev;
656	info->base		= base;
657	info->vaddr		= vaddr;
658
659	info->mtd.priv		= &info->chip;
660	info->mtd.name		= dev_name(&pdev->dev);
661	info->mtd.owner		= THIS_MODULE;
662
663	info->mtd.dev.parent	= &pdev->dev;
664
665	info->chip.IO_ADDR_R	= vaddr;
666	info->chip.IO_ADDR_W	= vaddr;
667	info->chip.chip_delay	= 0;
668	info->chip.select_chip	= nand_davinci_select_chip;
669
670	/* options such as NAND_BBT_USE_FLASH */
671	info->chip.bbt_options	= pdata->bbt_options;
672	/* options such as 16-bit widths */
673	info->chip.options	= pdata->options;
674	info->chip.bbt_td	= pdata->bbt_td;
675	info->chip.bbt_md	= pdata->bbt_md;
676	info->timing		= pdata->timing;
677
678	info->ioaddr		= (uint32_t __force) vaddr;
679
680	info->current_cs	= info->ioaddr;
681	info->core_chipsel	= pdev->id;
682	info->mask_chipsel	= pdata->mask_chipsel;
683
684	/* use nandboot-capable ALE/CLE masks by default */
685	info->mask_ale		= pdata->mask_ale ? : MASK_ALE;
686	info->mask_cle		= pdata->mask_cle ? : MASK_CLE;
687
688	/* Set address of hardware control function */
689	info->chip.cmd_ctrl	= nand_davinci_hwcontrol;
690	info->chip.dev_ready	= nand_davinci_dev_ready;
691
692	/* Speed up buffer I/O */
693	info->chip.read_buf     = nand_davinci_read_buf;
694	info->chip.write_buf    = nand_davinci_write_buf;
695
696	/* Use board-specific ECC config */
697	ecc_mode		= pdata->ecc_mode;
698
699	ret = -EINVAL;
700	switch (ecc_mode) {
701	case NAND_ECC_NONE:
702	case NAND_ECC_SOFT:
703		pdata->ecc_bits = 0;
704		break;
705	case NAND_ECC_HW:
706		if (pdata->ecc_bits == 4) {
707			/* No sanity checks:  CPUs must support this,
708			 * and the chips may not use NAND_BUSWIDTH_16.
709			 */
710
711			/* No sharing 4-bit hardware between chipselects yet */
712			spin_lock_irq(&davinci_nand_lock);
713			if (ecc4_busy)
714				ret = -EBUSY;
715			else
716				ecc4_busy = true;
717			spin_unlock_irq(&davinci_nand_lock);
718
719			if (ret == -EBUSY)
720				return ret;
721
722			info->chip.ecc.calculate = nand_davinci_calculate_4bit;
723			info->chip.ecc.correct = nand_davinci_correct_4bit;
724			info->chip.ecc.hwctl = nand_davinci_hwctl_4bit;
725			info->chip.ecc.bytes = 10;
726		} else {
727			info->chip.ecc.calculate = nand_davinci_calculate_1bit;
728			info->chip.ecc.correct = nand_davinci_correct_1bit;
729			info->chip.ecc.hwctl = nand_davinci_hwctl_1bit;
730			info->chip.ecc.bytes = 3;
731		}
732		info->chip.ecc.size = 512;
733		info->chip.ecc.strength = pdata->ecc_bits;
734		break;
735	default:
736		return -EINVAL;
737	}
738	info->chip.ecc.mode = ecc_mode;
739
740	info->clk = devm_clk_get(&pdev->dev, "aemif");
741	if (IS_ERR(info->clk)) {
742		ret = PTR_ERR(info->clk);
743		dev_dbg(&pdev->dev, "unable to get AEMIF clock, err %d\n", ret);
744		return ret;
745	}
746
747	ret = clk_prepare_enable(info->clk);
748	if (ret < 0) {
749		dev_dbg(&pdev->dev, "unable to enable AEMIF clock, err %d\n",
750			ret);
751		goto err_clk_enable;
752	}
753
754	spin_lock_irq(&davinci_nand_lock);
755
756	/* put CSxNAND into NAND mode */
757	val = davinci_nand_readl(info, NANDFCR_OFFSET);
758	val |= BIT(info->core_chipsel);
759	davinci_nand_writel(info, NANDFCR_OFFSET, val);
760
761	spin_unlock_irq(&davinci_nand_lock);
762
763	/* Scan to find existence of the device(s) */
764	ret = nand_scan_ident(&info->mtd, pdata->mask_chipsel ? 2 : 1, NULL);
765	if (ret < 0) {
766		dev_dbg(&pdev->dev, "no NAND chip(s) found\n");
767		goto err;
768	}
769
770	/* Update ECC layout if needed ... for 1-bit HW ECC, the default
771	 * is OK, but it allocates 6 bytes when only 3 are needed (for
772	 * each 512 bytes).  For the 4-bit HW ECC, that default is not
773	 * usable:  10 bytes are needed, not 6.
774	 */
775	if (pdata->ecc_bits == 4) {
776		int	chunks = info->mtd.writesize / 512;
777
778		if (!chunks || info->mtd.oobsize < 16) {
779			dev_dbg(&pdev->dev, "too small\n");
780			ret = -EINVAL;
781			goto err;
782		}
783
784		/* For small page chips, preserve the manufacturer's
785		 * badblock marking data ... and make sure a flash BBT
786		 * table marker fits in the free bytes.
787		 */
788		if (chunks == 1) {
789			info->ecclayout = hwecc4_small;
790			info->ecclayout.oobfree[1].length =
791				info->mtd.oobsize - 16;
792			goto syndrome_done;
793		}
794		if (chunks == 4) {
795			info->ecclayout = hwecc4_2048;
796			info->chip.ecc.mode = NAND_ECC_HW_OOB_FIRST;
797			goto syndrome_done;
798		}
799
800		/* 4KiB page chips are not yet supported. The eccpos from
801		 * nand_ecclayout cannot hold 80 bytes and change to eccpos[]
802		 * breaks userspace ioctl interface with mtd-utils. Once we
803		 * resolve this issue, NAND_ECC_HW_OOB_FIRST mode can be used
804		 * for the 4KiB page chips.
805		 *
806		 * TODO: Note that nand_ecclayout has now been expanded and can
807		 *  hold plenty of OOB entries.
808		 */
809		dev_warn(&pdev->dev, "no 4-bit ECC support yet "
810				"for 4KiB-page NAND\n");
811		ret = -EIO;
812		goto err;
813
814syndrome_done:
815		info->chip.ecc.layout = &info->ecclayout;
816	}
817
818	ret = nand_scan_tail(&info->mtd);
819	if (ret < 0)
820		goto err;
821
822	if (pdata->parts)
823		ret = mtd_device_parse_register(&info->mtd, NULL, NULL,
824					pdata->parts, pdata->nr_parts);
825	else {
826		struct mtd_part_parser_data	ppdata;
827
828		ppdata.of_node = pdev->dev.of_node;
829		ret = mtd_device_parse_register(&info->mtd, NULL, &ppdata,
830						NULL, 0);
831	}
832	if (ret < 0)
833		goto err;
834
835	val = davinci_nand_readl(info, NRCSR_OFFSET);
836	dev_info(&pdev->dev, "controller rev. %d.%d\n",
837	       (val >> 8) & 0xff, val & 0xff);
838
839	return 0;
840
841err:
842	clk_disable_unprepare(info->clk);
843
844err_clk_enable:
845	spin_lock_irq(&davinci_nand_lock);
846	if (ecc_mode == NAND_ECC_HW_SYNDROME)
847		ecc4_busy = false;
848	spin_unlock_irq(&davinci_nand_lock);
849	return ret;
850}
851
852static int nand_davinci_remove(struct platform_device *pdev)
853{
854	struct davinci_nand_info *info = platform_get_drvdata(pdev);
855
856	spin_lock_irq(&davinci_nand_lock);
857	if (info->chip.ecc.mode == NAND_ECC_HW_SYNDROME)
858		ecc4_busy = false;
859	spin_unlock_irq(&davinci_nand_lock);
860
861	nand_release(&info->mtd);
862
863	clk_disable_unprepare(info->clk);
864
865	return 0;
866}
867
868static struct platform_driver nand_davinci_driver = {
869	.probe		= nand_davinci_probe,
870	.remove		= nand_davinci_remove,
871	.driver		= {
872		.name	= "davinci_nand",
873		.of_match_table = of_match_ptr(davinci_nand_of_match),
874	},
875};
876MODULE_ALIAS("platform:davinci_nand");
877
878module_platform_driver(nand_davinci_driver);
879
880MODULE_LICENSE("GPL");
881MODULE_AUTHOR("Texas Instruments");
882MODULE_DESCRIPTION("Davinci NAND flash driver");
883
884