xref: /linux/drivers/mtd/nand/raw/s3c2410.c (revision 4b660dbd9ee2059850fd30e0df420ca7a38a1856)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright © 2004-2008 Simtec Electronics
4  *	http://armlinux.simtec.co.uk/
5  *	Ben Dooks <ben@simtec.co.uk>
6  *
7  * Samsung S3C2410/S3C2440/S3C2412 NAND driver
8 */
9 
10 #define pr_fmt(fmt) "nand-s3c2410: " fmt
11 
12 #ifdef CONFIG_MTD_NAND_S3C2410_DEBUG
13 #define DEBUG
14 #endif
15 
16 #include <linux/module.h>
17 #include <linux/types.h>
18 #include <linux/kernel.h>
19 #include <linux/string.h>
20 #include <linux/io.h>
21 #include <linux/ioport.h>
22 #include <linux/platform_device.h>
23 #include <linux/delay.h>
24 #include <linux/err.h>
25 #include <linux/slab.h>
26 #include <linux/clk.h>
27 #include <linux/cpufreq.h>
28 #include <linux/of.h>
29 
30 #include <linux/mtd/mtd.h>
31 #include <linux/mtd/rawnand.h>
32 #include <linux/mtd/partitions.h>
33 
34 #include <linux/platform_data/mtd-nand-s3c2410.h>
35 
36 #define S3C2410_NFREG(x) (x)
37 
38 #define S3C2410_NFCONF		S3C2410_NFREG(0x00)
39 #define S3C2410_NFCMD		S3C2410_NFREG(0x04)
40 #define S3C2410_NFADDR		S3C2410_NFREG(0x08)
41 #define S3C2410_NFDATA		S3C2410_NFREG(0x0C)
42 #define S3C2410_NFSTAT		S3C2410_NFREG(0x10)
43 #define S3C2410_NFECC		S3C2410_NFREG(0x14)
44 #define S3C2440_NFCONT		S3C2410_NFREG(0x04)
45 #define S3C2440_NFCMD		S3C2410_NFREG(0x08)
46 #define S3C2440_NFADDR		S3C2410_NFREG(0x0C)
47 #define S3C2440_NFDATA		S3C2410_NFREG(0x10)
48 #define S3C2440_NFSTAT		S3C2410_NFREG(0x20)
49 #define S3C2440_NFMECC0		S3C2410_NFREG(0x2C)
50 #define S3C2412_NFSTAT		S3C2410_NFREG(0x28)
51 #define S3C2412_NFMECC0		S3C2410_NFREG(0x34)
52 #define S3C2410_NFCONF_EN		(1<<15)
53 #define S3C2410_NFCONF_INITECC		(1<<12)
54 #define S3C2410_NFCONF_nFCE		(1<<11)
55 #define S3C2410_NFCONF_TACLS(x)		((x)<<8)
56 #define S3C2410_NFCONF_TWRPH0(x)	((x)<<4)
57 #define S3C2410_NFCONF_TWRPH1(x)	((x)<<0)
58 #define S3C2410_NFSTAT_BUSY		(1<<0)
59 #define S3C2440_NFCONF_TACLS(x)		((x)<<12)
60 #define S3C2440_NFCONF_TWRPH0(x)	((x)<<8)
61 #define S3C2440_NFCONF_TWRPH1(x)	((x)<<4)
62 #define S3C2440_NFCONT_INITECC		(1<<4)
63 #define S3C2440_NFCONT_nFCE		(1<<1)
64 #define S3C2440_NFCONT_ENABLE		(1<<0)
65 #define S3C2440_NFSTAT_READY		(1<<0)
66 #define S3C2412_NFCONF_NANDBOOT		(1<<31)
67 #define S3C2412_NFCONT_INIT_MAIN_ECC	(1<<5)
68 #define S3C2412_NFCONT_nFCE0		(1<<1)
69 #define S3C2412_NFSTAT_READY		(1<<0)
70 
71 /* new oob placement block for use with hardware ecc generation
72  */
73 static int s3c2410_ooblayout_ecc(struct mtd_info *mtd, int section,
74 				 struct mtd_oob_region *oobregion)
75 {
76 	if (section)
77 		return -ERANGE;
78 
79 	oobregion->offset = 0;
80 	oobregion->length = 3;
81 
82 	return 0;
83 }
84 
85 static int s3c2410_ooblayout_free(struct mtd_info *mtd, int section,
86 				  struct mtd_oob_region *oobregion)
87 {
88 	if (section)
89 		return -ERANGE;
90 
91 	oobregion->offset = 8;
92 	oobregion->length = 8;
93 
94 	return 0;
95 }
96 
97 static const struct mtd_ooblayout_ops s3c2410_ooblayout_ops = {
98 	.ecc = s3c2410_ooblayout_ecc,
99 	.free = s3c2410_ooblayout_free,
100 };
101 
102 /* controller and mtd information */
103 
104 struct s3c2410_nand_info;
105 
106 /**
107  * struct s3c2410_nand_mtd - driver MTD structure
108  * @chip: The NAND chip information.
109  * @set: The platform information supplied for this set of NAND chips.
110  * @info: Link back to the hardware information.
111 */
112 struct s3c2410_nand_mtd {
113 	struct nand_chip		chip;
114 	struct s3c2410_nand_set		*set;
115 	struct s3c2410_nand_info	*info;
116 };
117 
118 enum s3c_cpu_type {
119 	TYPE_S3C2410,
120 	TYPE_S3C2412,
121 	TYPE_S3C2440,
122 };
123 
124 enum s3c_nand_clk_state {
125 	CLOCK_DISABLE	= 0,
126 	CLOCK_ENABLE,
127 	CLOCK_SUSPEND,
128 };
129 
130 /* overview of the s3c2410 nand state */
131 
132 /**
133  * struct s3c2410_nand_info - NAND controller state.
134  * @controller: Base controller structure.
135  * @mtds: An array of MTD instances on this controller.
136  * @platform: The platform data for this board.
137  * @device: The platform device we bound to.
138  * @clk: The clock resource for this controller.
139  * @regs: The area mapped for the hardware registers.
140  * @sel_reg: Pointer to the register controlling the NAND selection.
141  * @sel_bit: The bit in @sel_reg to select the NAND chip.
142  * @mtd_count: The number of MTDs created from this controller.
143  * @save_sel: The contents of @sel_reg to be saved over suspend.
144  * @clk_rate: The clock rate from @clk.
145  * @clk_state: The current clock state.
146  * @cpu_type: The exact type of this controller.
147  */
148 struct s3c2410_nand_info {
149 	/* mtd info */
150 	struct nand_controller		controller;
151 	struct s3c2410_nand_mtd		*mtds;
152 	struct s3c2410_platform_nand	*platform;
153 
154 	/* device info */
155 	struct device			*device;
156 	struct clk			*clk;
157 	void __iomem			*regs;
158 	void __iomem			*sel_reg;
159 	int				sel_bit;
160 	int				mtd_count;
161 	unsigned long			save_sel;
162 	unsigned long			clk_rate;
163 	enum s3c_nand_clk_state		clk_state;
164 
165 	enum s3c_cpu_type		cpu_type;
166 };
167 
168 struct s3c24XX_nand_devtype_data {
169 	enum s3c_cpu_type type;
170 };
171 
172 static const struct s3c24XX_nand_devtype_data s3c2410_nand_devtype_data = {
173 	.type = TYPE_S3C2410,
174 };
175 
176 static const struct s3c24XX_nand_devtype_data s3c2412_nand_devtype_data = {
177 	.type = TYPE_S3C2412,
178 };
179 
180 static const struct s3c24XX_nand_devtype_data s3c2440_nand_devtype_data = {
181 	.type = TYPE_S3C2440,
182 };
183 
184 /* conversion functions */
185 
186 static struct s3c2410_nand_mtd *s3c2410_nand_mtd_toours(struct mtd_info *mtd)
187 {
188 	return container_of(mtd_to_nand(mtd), struct s3c2410_nand_mtd,
189 			    chip);
190 }
191 
192 static struct s3c2410_nand_info *s3c2410_nand_mtd_toinfo(struct mtd_info *mtd)
193 {
194 	return s3c2410_nand_mtd_toours(mtd)->info;
195 }
196 
197 static struct s3c2410_nand_info *to_nand_info(struct platform_device *dev)
198 {
199 	return platform_get_drvdata(dev);
200 }
201 
202 static struct s3c2410_platform_nand *to_nand_plat(struct platform_device *dev)
203 {
204 	return dev_get_platdata(&dev->dev);
205 }
206 
207 static inline int allow_clk_suspend(struct s3c2410_nand_info *info)
208 {
209 #ifdef CONFIG_MTD_NAND_S3C2410_CLKSTOP
210 	return 1;
211 #else
212 	return 0;
213 #endif
214 }
215 
216 /**
217  * s3c2410_nand_clk_set_state - Enable, disable or suspend NAND clock.
218  * @info: The controller instance.
219  * @new_state: State to which clock should be set.
220  */
221 static void s3c2410_nand_clk_set_state(struct s3c2410_nand_info *info,
222 		enum s3c_nand_clk_state new_state)
223 {
224 	if (!allow_clk_suspend(info) && new_state == CLOCK_SUSPEND)
225 		return;
226 
227 	if (info->clk_state == CLOCK_ENABLE) {
228 		if (new_state != CLOCK_ENABLE)
229 			clk_disable_unprepare(info->clk);
230 	} else {
231 		if (new_state == CLOCK_ENABLE)
232 			clk_prepare_enable(info->clk);
233 	}
234 
235 	info->clk_state = new_state;
236 }
237 
238 /* timing calculations */
239 
240 #define NS_IN_KHZ 1000000
241 
242 /**
243  * s3c_nand_calc_rate - calculate timing data.
244  * @wanted: The cycle time in nanoseconds.
245  * @clk: The clock rate in kHz.
246  * @max: The maximum divider value.
247  *
248  * Calculate the timing value from the given parameters.
249  */
250 static int s3c_nand_calc_rate(int wanted, unsigned long clk, int max)
251 {
252 	int result;
253 
254 	result = DIV_ROUND_UP((wanted * clk), NS_IN_KHZ);
255 
256 	pr_debug("result %d from %ld, %d\n", result, clk, wanted);
257 
258 	if (result > max) {
259 		pr_err("%d ns is too big for current clock rate %ld\n",
260 			wanted, clk);
261 		return -1;
262 	}
263 
264 	if (result < 1)
265 		result = 1;
266 
267 	return result;
268 }
269 
270 #define to_ns(ticks, clk) (((ticks) * NS_IN_KHZ) / (unsigned int)(clk))
271 
272 /* controller setup */
273 
274 /**
275  * s3c2410_nand_setrate - setup controller timing information.
276  * @info: The controller instance.
277  *
278  * Given the information supplied by the platform, calculate and set
279  * the necessary timing registers in the hardware to generate the
280  * necessary timing cycles to the hardware.
281  */
282 static int s3c2410_nand_setrate(struct s3c2410_nand_info *info)
283 {
284 	struct s3c2410_platform_nand *plat = info->platform;
285 	int tacls_max = (info->cpu_type == TYPE_S3C2412) ? 8 : 4;
286 	int tacls, twrph0, twrph1;
287 	unsigned long clkrate = clk_get_rate(info->clk);
288 	unsigned long set, cfg, mask;
289 	unsigned long flags;
290 
291 	/* calculate the timing information for the controller */
292 
293 	info->clk_rate = clkrate;
294 	clkrate /= 1000;	/* turn clock into kHz for ease of use */
295 
296 	if (plat != NULL) {
297 		tacls = s3c_nand_calc_rate(plat->tacls, clkrate, tacls_max);
298 		twrph0 = s3c_nand_calc_rate(plat->twrph0, clkrate, 8);
299 		twrph1 = s3c_nand_calc_rate(plat->twrph1, clkrate, 8);
300 	} else {
301 		/* default timings */
302 		tacls = tacls_max;
303 		twrph0 = 8;
304 		twrph1 = 8;
305 	}
306 
307 	if (tacls < 0 || twrph0 < 0 || twrph1 < 0) {
308 		dev_err(info->device, "cannot get suitable timings\n");
309 		return -EINVAL;
310 	}
311 
312 	dev_info(info->device, "Tacls=%d, %dns Twrph0=%d %dns, Twrph1=%d %dns\n",
313 		tacls, to_ns(tacls, clkrate), twrph0, to_ns(twrph0, clkrate),
314 						twrph1, to_ns(twrph1, clkrate));
315 
316 	switch (info->cpu_type) {
317 	case TYPE_S3C2410:
318 		mask = (S3C2410_NFCONF_TACLS(3) |
319 			S3C2410_NFCONF_TWRPH0(7) |
320 			S3C2410_NFCONF_TWRPH1(7));
321 		set = S3C2410_NFCONF_EN;
322 		set |= S3C2410_NFCONF_TACLS(tacls - 1);
323 		set |= S3C2410_NFCONF_TWRPH0(twrph0 - 1);
324 		set |= S3C2410_NFCONF_TWRPH1(twrph1 - 1);
325 		break;
326 
327 	case TYPE_S3C2440:
328 	case TYPE_S3C2412:
329 		mask = (S3C2440_NFCONF_TACLS(tacls_max - 1) |
330 			S3C2440_NFCONF_TWRPH0(7) |
331 			S3C2440_NFCONF_TWRPH1(7));
332 
333 		set = S3C2440_NFCONF_TACLS(tacls - 1);
334 		set |= S3C2440_NFCONF_TWRPH0(twrph0 - 1);
335 		set |= S3C2440_NFCONF_TWRPH1(twrph1 - 1);
336 		break;
337 
338 	default:
339 		BUG();
340 	}
341 
342 	local_irq_save(flags);
343 
344 	cfg = readl(info->regs + S3C2410_NFCONF);
345 	cfg &= ~mask;
346 	cfg |= set;
347 	writel(cfg, info->regs + S3C2410_NFCONF);
348 
349 	local_irq_restore(flags);
350 
351 	dev_dbg(info->device, "NF_CONF is 0x%lx\n", cfg);
352 
353 	return 0;
354 }
355 
356 /**
357  * s3c2410_nand_inithw - basic hardware initialisation
358  * @info: The hardware state.
359  *
360  * Do the basic initialisation of the hardware, using s3c2410_nand_setrate()
361  * to setup the hardware access speeds and set the controller to be enabled.
362 */
363 static int s3c2410_nand_inithw(struct s3c2410_nand_info *info)
364 {
365 	int ret;
366 
367 	ret = s3c2410_nand_setrate(info);
368 	if (ret < 0)
369 		return ret;
370 
371 	switch (info->cpu_type) {
372 	case TYPE_S3C2410:
373 	default:
374 		break;
375 
376 	case TYPE_S3C2440:
377 	case TYPE_S3C2412:
378 		/* enable the controller and de-assert nFCE */
379 
380 		writel(S3C2440_NFCONT_ENABLE, info->regs + S3C2440_NFCONT);
381 	}
382 
383 	return 0;
384 }
385 
386 /**
387  * s3c2410_nand_select_chip - select the given nand chip
388  * @this: NAND chip object.
389  * @chip: The chip number.
390  *
391  * This is called by the MTD layer to either select a given chip for the
392  * @mtd instance, or to indicate that the access has finished and the
393  * chip can be de-selected.
394  *
395  * The routine ensures that the nFCE line is correctly setup, and any
396  * platform specific selection code is called to route nFCE to the specific
397  * chip.
398  */
399 static void s3c2410_nand_select_chip(struct nand_chip *this, int chip)
400 {
401 	struct s3c2410_nand_info *info;
402 	struct s3c2410_nand_mtd *nmtd;
403 	unsigned long cur;
404 
405 	nmtd = nand_get_controller_data(this);
406 	info = nmtd->info;
407 
408 	if (chip != -1)
409 		s3c2410_nand_clk_set_state(info, CLOCK_ENABLE);
410 
411 	cur = readl(info->sel_reg);
412 
413 	if (chip == -1) {
414 		cur |= info->sel_bit;
415 	} else {
416 		if (nmtd->set != NULL && chip > nmtd->set->nr_chips) {
417 			dev_err(info->device, "invalid chip %d\n", chip);
418 			return;
419 		}
420 
421 		if (info->platform != NULL) {
422 			if (info->platform->select_chip != NULL)
423 				(info->platform->select_chip) (nmtd->set, chip);
424 		}
425 
426 		cur &= ~info->sel_bit;
427 	}
428 
429 	writel(cur, info->sel_reg);
430 
431 	if (chip == -1)
432 		s3c2410_nand_clk_set_state(info, CLOCK_SUSPEND);
433 }
434 
435 /* s3c2410_nand_hwcontrol
436  *
437  * Issue command and address cycles to the chip
438 */
439 
440 static void s3c2410_nand_hwcontrol(struct nand_chip *chip, int cmd,
441 				   unsigned int ctrl)
442 {
443 	struct mtd_info *mtd = nand_to_mtd(chip);
444 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
445 
446 	if (cmd == NAND_CMD_NONE)
447 		return;
448 
449 	if (ctrl & NAND_CLE)
450 		writeb(cmd, info->regs + S3C2410_NFCMD);
451 	else
452 		writeb(cmd, info->regs + S3C2410_NFADDR);
453 }
454 
455 /* command and control functions */
456 
457 static void s3c2440_nand_hwcontrol(struct nand_chip *chip, int cmd,
458 				   unsigned int ctrl)
459 {
460 	struct mtd_info *mtd = nand_to_mtd(chip);
461 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
462 
463 	if (cmd == NAND_CMD_NONE)
464 		return;
465 
466 	if (ctrl & NAND_CLE)
467 		writeb(cmd, info->regs + S3C2440_NFCMD);
468 	else
469 		writeb(cmd, info->regs + S3C2440_NFADDR);
470 }
471 
472 /* s3c2410_nand_devready()
473  *
474  * returns 0 if the nand is busy, 1 if it is ready
475 */
476 
477 static int s3c2410_nand_devready(struct nand_chip *chip)
478 {
479 	struct mtd_info *mtd = nand_to_mtd(chip);
480 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
481 	return readb(info->regs + S3C2410_NFSTAT) & S3C2410_NFSTAT_BUSY;
482 }
483 
484 static int s3c2440_nand_devready(struct nand_chip *chip)
485 {
486 	struct mtd_info *mtd = nand_to_mtd(chip);
487 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
488 	return readb(info->regs + S3C2440_NFSTAT) & S3C2440_NFSTAT_READY;
489 }
490 
491 static int s3c2412_nand_devready(struct nand_chip *chip)
492 {
493 	struct mtd_info *mtd = nand_to_mtd(chip);
494 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
495 	return readb(info->regs + S3C2412_NFSTAT) & S3C2412_NFSTAT_READY;
496 }
497 
498 /* ECC handling functions */
499 
500 static int s3c2410_nand_correct_data(struct nand_chip *chip, u_char *dat,
501 				     u_char *read_ecc, u_char *calc_ecc)
502 {
503 	struct mtd_info *mtd = nand_to_mtd(chip);
504 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
505 	unsigned int diff0, diff1, diff2;
506 	unsigned int bit, byte;
507 
508 	pr_debug("%s(%p,%p,%p,%p)\n", __func__, mtd, dat, read_ecc, calc_ecc);
509 
510 	diff0 = read_ecc[0] ^ calc_ecc[0];
511 	diff1 = read_ecc[1] ^ calc_ecc[1];
512 	diff2 = read_ecc[2] ^ calc_ecc[2];
513 
514 	pr_debug("%s: rd %*phN calc %*phN diff %02x%02x%02x\n",
515 		 __func__, 3, read_ecc, 3, calc_ecc,
516 		 diff0, diff1, diff2);
517 
518 	if (diff0 == 0 && diff1 == 0 && diff2 == 0)
519 		return 0;		/* ECC is ok */
520 
521 	/* sometimes people do not think about using the ECC, so check
522 	 * to see if we have an 0xff,0xff,0xff read ECC and then ignore
523 	 * the error, on the assumption that this is an un-eccd page.
524 	 */
525 	if (read_ecc[0] == 0xff && read_ecc[1] == 0xff && read_ecc[2] == 0xff
526 	    && info->platform->ignore_unset_ecc)
527 		return 0;
528 
529 	/* Can we correct this ECC (ie, one row and column change).
530 	 * Note, this is similar to the 256 error code on smartmedia */
531 
532 	if (((diff0 ^ (diff0 >> 1)) & 0x55) == 0x55 &&
533 	    ((diff1 ^ (diff1 >> 1)) & 0x55) == 0x55 &&
534 	    ((diff2 ^ (diff2 >> 1)) & 0x55) == 0x55) {
535 		/* calculate the bit position of the error */
536 
537 		bit  = ((diff2 >> 3) & 1) |
538 		       ((diff2 >> 4) & 2) |
539 		       ((diff2 >> 5) & 4);
540 
541 		/* calculate the byte position of the error */
542 
543 		byte = ((diff2 << 7) & 0x100) |
544 		       ((diff1 << 0) & 0x80)  |
545 		       ((diff1 << 1) & 0x40)  |
546 		       ((diff1 << 2) & 0x20)  |
547 		       ((diff1 << 3) & 0x10)  |
548 		       ((diff0 >> 4) & 0x08)  |
549 		       ((diff0 >> 3) & 0x04)  |
550 		       ((diff0 >> 2) & 0x02)  |
551 		       ((diff0 >> 1) & 0x01);
552 
553 		dev_dbg(info->device, "correcting error bit %d, byte %d\n",
554 			bit, byte);
555 
556 		dat[byte] ^= (1 << bit);
557 		return 1;
558 	}
559 
560 	/* if there is only one bit difference in the ECC, then
561 	 * one of only a row or column parity has changed, which
562 	 * means the error is most probably in the ECC itself */
563 
564 	diff0 |= (diff1 << 8);
565 	diff0 |= (diff2 << 16);
566 
567 	/* equal to "(diff0 & ~(1 << __ffs(diff0)))" */
568 	if ((diff0 & (diff0 - 1)) == 0)
569 		return 1;
570 
571 	return -1;
572 }
573 
574 /* ECC functions
575  *
576  * These allow the s3c2410 and s3c2440 to use the controller's ECC
577  * generator block to ECC the data as it passes through]
578 */
579 
580 static void s3c2410_nand_enable_hwecc(struct nand_chip *chip, int mode)
581 {
582 	struct s3c2410_nand_info *info;
583 	unsigned long ctrl;
584 
585 	info = s3c2410_nand_mtd_toinfo(nand_to_mtd(chip));
586 	ctrl = readl(info->regs + S3C2410_NFCONF);
587 	ctrl |= S3C2410_NFCONF_INITECC;
588 	writel(ctrl, info->regs + S3C2410_NFCONF);
589 }
590 
591 static void s3c2412_nand_enable_hwecc(struct nand_chip *chip, int mode)
592 {
593 	struct s3c2410_nand_info *info;
594 	unsigned long ctrl;
595 
596 	info = s3c2410_nand_mtd_toinfo(nand_to_mtd(chip));
597 	ctrl = readl(info->regs + S3C2440_NFCONT);
598 	writel(ctrl | S3C2412_NFCONT_INIT_MAIN_ECC,
599 	       info->regs + S3C2440_NFCONT);
600 }
601 
602 static void s3c2440_nand_enable_hwecc(struct nand_chip *chip, int mode)
603 {
604 	struct s3c2410_nand_info *info;
605 	unsigned long ctrl;
606 
607 	info = s3c2410_nand_mtd_toinfo(nand_to_mtd(chip));
608 	ctrl = readl(info->regs + S3C2440_NFCONT);
609 	writel(ctrl | S3C2440_NFCONT_INITECC, info->regs + S3C2440_NFCONT);
610 }
611 
612 static int s3c2410_nand_calculate_ecc(struct nand_chip *chip,
613 				      const u_char *dat, u_char *ecc_code)
614 {
615 	struct mtd_info *mtd = nand_to_mtd(chip);
616 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
617 
618 	ecc_code[0] = readb(info->regs + S3C2410_NFECC + 0);
619 	ecc_code[1] = readb(info->regs + S3C2410_NFECC + 1);
620 	ecc_code[2] = readb(info->regs + S3C2410_NFECC + 2);
621 
622 	pr_debug("%s: returning ecc %*phN\n", __func__, 3, ecc_code);
623 
624 	return 0;
625 }
626 
627 static int s3c2412_nand_calculate_ecc(struct nand_chip *chip,
628 				      const u_char *dat, u_char *ecc_code)
629 {
630 	struct mtd_info *mtd = nand_to_mtd(chip);
631 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
632 	unsigned long ecc = readl(info->regs + S3C2412_NFMECC0);
633 
634 	ecc_code[0] = ecc;
635 	ecc_code[1] = ecc >> 8;
636 	ecc_code[2] = ecc >> 16;
637 
638 	pr_debug("%s: returning ecc %*phN\n", __func__, 3, ecc_code);
639 
640 	return 0;
641 }
642 
643 static int s3c2440_nand_calculate_ecc(struct nand_chip *chip,
644 				      const u_char *dat, u_char *ecc_code)
645 {
646 	struct mtd_info *mtd = nand_to_mtd(chip);
647 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
648 	unsigned long ecc = readl(info->regs + S3C2440_NFMECC0);
649 
650 	ecc_code[0] = ecc;
651 	ecc_code[1] = ecc >> 8;
652 	ecc_code[2] = ecc >> 16;
653 
654 	pr_debug("%s: returning ecc %06lx\n", __func__, ecc & 0xffffff);
655 
656 	return 0;
657 }
658 
659 /* over-ride the standard functions for a little more speed. We can
660  * use read/write block to move the data buffers to/from the controller
661 */
662 
663 static void s3c2410_nand_read_buf(struct nand_chip *this, u_char *buf, int len)
664 {
665 	readsb(this->legacy.IO_ADDR_R, buf, len);
666 }
667 
668 static void s3c2440_nand_read_buf(struct nand_chip *this, u_char *buf, int len)
669 {
670 	struct mtd_info *mtd = nand_to_mtd(this);
671 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
672 
673 	readsl(info->regs + S3C2440_NFDATA, buf, len >> 2);
674 
675 	/* cleanup if we've got less than a word to do */
676 	if (len & 3) {
677 		buf += len & ~3;
678 
679 		for (; len & 3; len--)
680 			*buf++ = readb(info->regs + S3C2440_NFDATA);
681 	}
682 }
683 
684 static void s3c2410_nand_write_buf(struct nand_chip *this, const u_char *buf,
685 				   int len)
686 {
687 	writesb(this->legacy.IO_ADDR_W, buf, len);
688 }
689 
690 static void s3c2440_nand_write_buf(struct nand_chip *this, const u_char *buf,
691 				   int len)
692 {
693 	struct mtd_info *mtd = nand_to_mtd(this);
694 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
695 
696 	writesl(info->regs + S3C2440_NFDATA, buf, len >> 2);
697 
698 	/* cleanup any fractional write */
699 	if (len & 3) {
700 		buf += len & ~3;
701 
702 		for (; len & 3; len--, buf++)
703 			writeb(*buf, info->regs + S3C2440_NFDATA);
704 	}
705 }
706 
707 /* device management functions */
708 
709 static void s3c24xx_nand_remove(struct platform_device *pdev)
710 {
711 	struct s3c2410_nand_info *info = to_nand_info(pdev);
712 
713 	if (info == NULL)
714 		return;
715 
716 	/* Release all our mtds  and their partitions, then go through
717 	 * freeing the resources used
718 	 */
719 
720 	if (info->mtds != NULL) {
721 		struct s3c2410_nand_mtd *ptr = info->mtds;
722 		int mtdno;
723 
724 		for (mtdno = 0; mtdno < info->mtd_count; mtdno++, ptr++) {
725 			pr_debug("releasing mtd %d (%p)\n", mtdno, ptr);
726 			WARN_ON(mtd_device_unregister(nand_to_mtd(&ptr->chip)));
727 			nand_cleanup(&ptr->chip);
728 		}
729 	}
730 
731 	/* free the common resources */
732 
733 	if (!IS_ERR(info->clk))
734 		s3c2410_nand_clk_set_state(info, CLOCK_DISABLE);
735 }
736 
737 static int s3c2410_nand_add_partition(struct s3c2410_nand_info *info,
738 				      struct s3c2410_nand_mtd *mtd,
739 				      struct s3c2410_nand_set *set)
740 {
741 	if (set) {
742 		struct mtd_info *mtdinfo = nand_to_mtd(&mtd->chip);
743 
744 		mtdinfo->name = set->name;
745 
746 		return mtd_device_register(mtdinfo, set->partitions,
747 					   set->nr_partitions);
748 	}
749 
750 	return -ENODEV;
751 }
752 
753 static int s3c2410_nand_setup_interface(struct nand_chip *chip, int csline,
754 					const struct nand_interface_config *conf)
755 {
756 	struct mtd_info *mtd = nand_to_mtd(chip);
757 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
758 	struct s3c2410_platform_nand *pdata = info->platform;
759 	const struct nand_sdr_timings *timings;
760 	int tacls;
761 
762 	timings = nand_get_sdr_timings(conf);
763 	if (IS_ERR(timings))
764 		return -ENOTSUPP;
765 
766 	tacls = timings->tCLS_min - timings->tWP_min;
767 	if (tacls < 0)
768 		tacls = 0;
769 
770 	pdata->tacls  = DIV_ROUND_UP(tacls, 1000);
771 	pdata->twrph0 = DIV_ROUND_UP(timings->tWP_min, 1000);
772 	pdata->twrph1 = DIV_ROUND_UP(timings->tCLH_min, 1000);
773 
774 	return s3c2410_nand_setrate(info);
775 }
776 
777 /**
778  * s3c2410_nand_init_chip - initialise a single instance of an chip
779  * @info: The base NAND controller the chip is on.
780  * @nmtd: The new controller MTD instance to fill in.
781  * @set: The information passed from the board specific platform data.
782  *
783  * Initialise the given @nmtd from the information in @info and @set. This
784  * readies the structure for use with the MTD layer functions by ensuring
785  * all pointers are setup and the necessary control routines selected.
786  */
787 static void s3c2410_nand_init_chip(struct s3c2410_nand_info *info,
788 				   struct s3c2410_nand_mtd *nmtd,
789 				   struct s3c2410_nand_set *set)
790 {
791 	struct device_node *np = info->device->of_node;
792 	struct nand_chip *chip = &nmtd->chip;
793 	void __iomem *regs = info->regs;
794 
795 	nand_set_flash_node(chip, set->of_node);
796 
797 	chip->legacy.write_buf    = s3c2410_nand_write_buf;
798 	chip->legacy.read_buf     = s3c2410_nand_read_buf;
799 	chip->legacy.select_chip  = s3c2410_nand_select_chip;
800 	chip->legacy.chip_delay   = 50;
801 	nand_set_controller_data(chip, nmtd);
802 	chip->options	   = set->options;
803 	chip->controller   = &info->controller;
804 
805 	/*
806 	 * let's keep behavior unchanged for legacy boards booting via pdata and
807 	 * auto-detect timings only when booting with a device tree.
808 	 */
809 	if (!np)
810 		chip->options |= NAND_KEEP_TIMINGS;
811 
812 	switch (info->cpu_type) {
813 	case TYPE_S3C2410:
814 		chip->legacy.IO_ADDR_W = regs + S3C2410_NFDATA;
815 		info->sel_reg   = regs + S3C2410_NFCONF;
816 		info->sel_bit	= S3C2410_NFCONF_nFCE;
817 		chip->legacy.cmd_ctrl  = s3c2410_nand_hwcontrol;
818 		chip->legacy.dev_ready = s3c2410_nand_devready;
819 		break;
820 
821 	case TYPE_S3C2440:
822 		chip->legacy.IO_ADDR_W = regs + S3C2440_NFDATA;
823 		info->sel_reg   = regs + S3C2440_NFCONT;
824 		info->sel_bit	= S3C2440_NFCONT_nFCE;
825 		chip->legacy.cmd_ctrl  = s3c2440_nand_hwcontrol;
826 		chip->legacy.dev_ready = s3c2440_nand_devready;
827 		chip->legacy.read_buf  = s3c2440_nand_read_buf;
828 		chip->legacy.write_buf	= s3c2440_nand_write_buf;
829 		break;
830 
831 	case TYPE_S3C2412:
832 		chip->legacy.IO_ADDR_W = regs + S3C2440_NFDATA;
833 		info->sel_reg   = regs + S3C2440_NFCONT;
834 		info->sel_bit	= S3C2412_NFCONT_nFCE0;
835 		chip->legacy.cmd_ctrl  = s3c2440_nand_hwcontrol;
836 		chip->legacy.dev_ready = s3c2412_nand_devready;
837 
838 		if (readl(regs + S3C2410_NFCONF) & S3C2412_NFCONF_NANDBOOT)
839 			dev_info(info->device, "System booted from NAND\n");
840 
841 		break;
842 	}
843 
844 	chip->legacy.IO_ADDR_R = chip->legacy.IO_ADDR_W;
845 
846 	nmtd->info	   = info;
847 	nmtd->set	   = set;
848 
849 	chip->ecc.engine_type = info->platform->engine_type;
850 
851 	/*
852 	 * If you use u-boot BBT creation code, specifying this flag will
853 	 * let the kernel fish out the BBT from the NAND.
854 	 */
855 	if (set->flash_bbt)
856 		chip->bbt_options |= NAND_BBT_USE_FLASH;
857 }
858 
859 /**
860  * s3c2410_nand_attach_chip - Init the ECC engine after NAND scan
861  * @chip: The NAND chip
862  *
863  * This hook is called by the core after the identification of the NAND chip,
864  * once the relevant per-chip information is up to date.. This call ensure that
865  * we update the internal state accordingly.
866  *
867  * The internal state is currently limited to the ECC state information.
868 */
869 static int s3c2410_nand_attach_chip(struct nand_chip *chip)
870 {
871 	struct mtd_info *mtd = nand_to_mtd(chip);
872 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
873 
874 	switch (chip->ecc.engine_type) {
875 
876 	case NAND_ECC_ENGINE_TYPE_NONE:
877 		dev_info(info->device, "ECC disabled\n");
878 		break;
879 
880 	case NAND_ECC_ENGINE_TYPE_SOFT:
881 		/*
882 		 * This driver expects Hamming based ECC when engine_type is set
883 		 * to NAND_ECC_ENGINE_TYPE_SOFT. Force ecc.algo to
884 		 * NAND_ECC_ALGO_HAMMING to avoid adding an extra ecc_algo field
885 		 * to s3c2410_platform_nand.
886 		 */
887 		chip->ecc.algo = NAND_ECC_ALGO_HAMMING;
888 		dev_info(info->device, "soft ECC\n");
889 		break;
890 
891 	case NAND_ECC_ENGINE_TYPE_ON_HOST:
892 		chip->ecc.calculate = s3c2410_nand_calculate_ecc;
893 		chip->ecc.correct   = s3c2410_nand_correct_data;
894 		chip->ecc.strength  = 1;
895 
896 		switch (info->cpu_type) {
897 		case TYPE_S3C2410:
898 			chip->ecc.hwctl	    = s3c2410_nand_enable_hwecc;
899 			chip->ecc.calculate = s3c2410_nand_calculate_ecc;
900 			break;
901 
902 		case TYPE_S3C2412:
903 			chip->ecc.hwctl     = s3c2412_nand_enable_hwecc;
904 			chip->ecc.calculate = s3c2412_nand_calculate_ecc;
905 			break;
906 
907 		case TYPE_S3C2440:
908 			chip->ecc.hwctl     = s3c2440_nand_enable_hwecc;
909 			chip->ecc.calculate = s3c2440_nand_calculate_ecc;
910 			break;
911 		}
912 
913 		dev_dbg(info->device, "chip %p => page shift %d\n",
914 			chip, chip->page_shift);
915 
916 		/* change the behaviour depending on whether we are using
917 		 * the large or small page nand device */
918 		if (chip->page_shift > 10) {
919 			chip->ecc.size	    = 256;
920 			chip->ecc.bytes	    = 3;
921 		} else {
922 			chip->ecc.size	    = 512;
923 			chip->ecc.bytes	    = 3;
924 			mtd_set_ooblayout(nand_to_mtd(chip),
925 					  &s3c2410_ooblayout_ops);
926 		}
927 
928 		dev_info(info->device, "hardware ECC\n");
929 		break;
930 
931 	default:
932 		dev_err(info->device, "invalid ECC mode!\n");
933 		return -EINVAL;
934 	}
935 
936 	if (chip->bbt_options & NAND_BBT_USE_FLASH)
937 		chip->options |= NAND_SKIP_BBTSCAN;
938 
939 	return 0;
940 }
941 
942 static const struct nand_controller_ops s3c24xx_nand_controller_ops = {
943 	.attach_chip = s3c2410_nand_attach_chip,
944 	.setup_interface = s3c2410_nand_setup_interface,
945 };
946 
947 static const struct of_device_id s3c24xx_nand_dt_ids[] = {
948 	{
949 		.compatible = "samsung,s3c2410-nand",
950 		.data = &s3c2410_nand_devtype_data,
951 	}, {
952 		/* also compatible with s3c6400 */
953 		.compatible = "samsung,s3c2412-nand",
954 		.data = &s3c2412_nand_devtype_data,
955 	}, {
956 		.compatible = "samsung,s3c2440-nand",
957 		.data = &s3c2440_nand_devtype_data,
958 	},
959 	{ /* sentinel */ }
960 };
961 MODULE_DEVICE_TABLE(of, s3c24xx_nand_dt_ids);
962 
963 static int s3c24xx_nand_probe_dt(struct platform_device *pdev)
964 {
965 	const struct s3c24XX_nand_devtype_data *devtype_data;
966 	struct s3c2410_platform_nand *pdata;
967 	struct s3c2410_nand_info *info = platform_get_drvdata(pdev);
968 	struct device_node *np = pdev->dev.of_node, *child;
969 	struct s3c2410_nand_set *sets;
970 
971 	devtype_data = of_device_get_match_data(&pdev->dev);
972 	if (!devtype_data)
973 		return -ENODEV;
974 
975 	info->cpu_type = devtype_data->type;
976 
977 	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
978 	if (!pdata)
979 		return -ENOMEM;
980 
981 	pdev->dev.platform_data = pdata;
982 
983 	pdata->nr_sets = of_get_child_count(np);
984 	if (!pdata->nr_sets)
985 		return 0;
986 
987 	sets = devm_kcalloc(&pdev->dev, pdata->nr_sets, sizeof(*sets),
988 			    GFP_KERNEL);
989 	if (!sets)
990 		return -ENOMEM;
991 
992 	pdata->sets = sets;
993 
994 	for_each_available_child_of_node(np, child) {
995 		sets->name = (char *)child->name;
996 		sets->of_node = child;
997 		sets->nr_chips = 1;
998 
999 		of_node_get(child);
1000 
1001 		sets++;
1002 	}
1003 
1004 	return 0;
1005 }
1006 
1007 static int s3c24xx_nand_probe_pdata(struct platform_device *pdev)
1008 {
1009 	struct s3c2410_nand_info *info = platform_get_drvdata(pdev);
1010 
1011 	info->cpu_type = platform_get_device_id(pdev)->driver_data;
1012 
1013 	return 0;
1014 }
1015 
1016 /* s3c24xx_nand_probe
1017  *
1018  * called by device layer when it finds a device matching
1019  * one our driver can handled. This code checks to see if
1020  * it can allocate all necessary resources then calls the
1021  * nand layer to look for devices
1022 */
1023 static int s3c24xx_nand_probe(struct platform_device *pdev)
1024 {
1025 	struct s3c2410_platform_nand *plat;
1026 	struct s3c2410_nand_info *info;
1027 	struct s3c2410_nand_mtd *nmtd;
1028 	struct s3c2410_nand_set *sets;
1029 	struct resource *res;
1030 	int err = 0;
1031 	int size;
1032 	int nr_sets;
1033 	int setno;
1034 
1035 	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
1036 	if (info == NULL) {
1037 		err = -ENOMEM;
1038 		goto exit_error;
1039 	}
1040 
1041 	platform_set_drvdata(pdev, info);
1042 
1043 	nand_controller_init(&info->controller);
1044 	info->controller.ops = &s3c24xx_nand_controller_ops;
1045 
1046 	/* get the clock source and enable it */
1047 
1048 	info->clk = devm_clk_get(&pdev->dev, "nand");
1049 	if (IS_ERR(info->clk)) {
1050 		dev_err(&pdev->dev, "failed to get clock\n");
1051 		err = -ENOENT;
1052 		goto exit_error;
1053 	}
1054 
1055 	s3c2410_nand_clk_set_state(info, CLOCK_ENABLE);
1056 
1057 	if (pdev->dev.of_node)
1058 		err = s3c24xx_nand_probe_dt(pdev);
1059 	else
1060 		err = s3c24xx_nand_probe_pdata(pdev);
1061 
1062 	if (err)
1063 		goto exit_error;
1064 
1065 	plat = to_nand_plat(pdev);
1066 
1067 	/* allocate and map the resource */
1068 
1069 	/* currently we assume we have the one resource */
1070 	res = pdev->resource;
1071 	size = resource_size(res);
1072 
1073 	info->device	= &pdev->dev;
1074 	info->platform	= plat;
1075 
1076 	info->regs = devm_ioremap_resource(&pdev->dev, res);
1077 	if (IS_ERR(info->regs)) {
1078 		err = PTR_ERR(info->regs);
1079 		goto exit_error;
1080 	}
1081 
1082 	dev_dbg(&pdev->dev, "mapped registers at %p\n", info->regs);
1083 
1084 	if (!plat->sets || plat->nr_sets < 1) {
1085 		err = -EINVAL;
1086 		goto exit_error;
1087 	}
1088 
1089 	sets = plat->sets;
1090 	nr_sets = plat->nr_sets;
1091 
1092 	info->mtd_count = nr_sets;
1093 
1094 	/* allocate our information */
1095 
1096 	size = nr_sets * sizeof(*info->mtds);
1097 	info->mtds = devm_kzalloc(&pdev->dev, size, GFP_KERNEL);
1098 	if (info->mtds == NULL) {
1099 		err = -ENOMEM;
1100 		goto exit_error;
1101 	}
1102 
1103 	/* initialise all possible chips */
1104 
1105 	nmtd = info->mtds;
1106 
1107 	for (setno = 0; setno < nr_sets; setno++, nmtd++, sets++) {
1108 		struct mtd_info *mtd = nand_to_mtd(&nmtd->chip);
1109 
1110 		pr_debug("initialising set %d (%p, info %p)\n",
1111 			 setno, nmtd, info);
1112 
1113 		mtd->dev.parent = &pdev->dev;
1114 		s3c2410_nand_init_chip(info, nmtd, sets);
1115 
1116 		err = nand_scan(&nmtd->chip, sets ? sets->nr_chips : 1);
1117 		if (err)
1118 			goto exit_error;
1119 
1120 		s3c2410_nand_add_partition(info, nmtd, sets);
1121 	}
1122 
1123 	/* initialise the hardware */
1124 	err = s3c2410_nand_inithw(info);
1125 	if (err != 0)
1126 		goto exit_error;
1127 
1128 	if (allow_clk_suspend(info)) {
1129 		dev_info(&pdev->dev, "clock idle support enabled\n");
1130 		s3c2410_nand_clk_set_state(info, CLOCK_SUSPEND);
1131 	}
1132 
1133 	return 0;
1134 
1135  exit_error:
1136 	s3c24xx_nand_remove(pdev);
1137 
1138 	if (err == 0)
1139 		err = -EINVAL;
1140 	return err;
1141 }
1142 
1143 /* PM Support */
1144 #ifdef CONFIG_PM
1145 
1146 static int s3c24xx_nand_suspend(struct platform_device *dev, pm_message_t pm)
1147 {
1148 	struct s3c2410_nand_info *info = platform_get_drvdata(dev);
1149 
1150 	if (info) {
1151 		info->save_sel = readl(info->sel_reg);
1152 
1153 		/* For the moment, we must ensure nFCE is high during
1154 		 * the time we are suspended. This really should be
1155 		 * handled by suspending the MTDs we are using, but
1156 		 * that is currently not the case. */
1157 
1158 		writel(info->save_sel | info->sel_bit, info->sel_reg);
1159 
1160 		s3c2410_nand_clk_set_state(info, CLOCK_DISABLE);
1161 	}
1162 
1163 	return 0;
1164 }
1165 
1166 static int s3c24xx_nand_resume(struct platform_device *dev)
1167 {
1168 	struct s3c2410_nand_info *info = platform_get_drvdata(dev);
1169 	unsigned long sel;
1170 
1171 	if (info) {
1172 		s3c2410_nand_clk_set_state(info, CLOCK_ENABLE);
1173 		s3c2410_nand_inithw(info);
1174 
1175 		/* Restore the state of the nFCE line. */
1176 
1177 		sel = readl(info->sel_reg);
1178 		sel &= ~info->sel_bit;
1179 		sel |= info->save_sel & info->sel_bit;
1180 		writel(sel, info->sel_reg);
1181 
1182 		s3c2410_nand_clk_set_state(info, CLOCK_SUSPEND);
1183 	}
1184 
1185 	return 0;
1186 }
1187 
1188 #else
1189 #define s3c24xx_nand_suspend NULL
1190 #define s3c24xx_nand_resume NULL
1191 #endif
1192 
1193 /* driver device registration */
1194 
1195 static const struct platform_device_id s3c24xx_driver_ids[] = {
1196 	{
1197 		.name		= "s3c2410-nand",
1198 		.driver_data	= TYPE_S3C2410,
1199 	}, {
1200 		.name		= "s3c2440-nand",
1201 		.driver_data	= TYPE_S3C2440,
1202 	}, {
1203 		.name		= "s3c2412-nand",
1204 		.driver_data	= TYPE_S3C2412,
1205 	}, {
1206 		.name		= "s3c6400-nand",
1207 		.driver_data	= TYPE_S3C2412, /* compatible with 2412 */
1208 	},
1209 	{ }
1210 };
1211 
1212 MODULE_DEVICE_TABLE(platform, s3c24xx_driver_ids);
1213 
1214 static struct platform_driver s3c24xx_nand_driver = {
1215 	.probe		= s3c24xx_nand_probe,
1216 	.remove_new	= s3c24xx_nand_remove,
1217 	.suspend	= s3c24xx_nand_suspend,
1218 	.resume		= s3c24xx_nand_resume,
1219 	.id_table	= s3c24xx_driver_ids,
1220 	.driver		= {
1221 		.name	= "s3c24xx-nand",
1222 		.of_match_table = s3c24xx_nand_dt_ids,
1223 	},
1224 };
1225 
1226 module_platform_driver(s3c24xx_nand_driver);
1227 
1228 MODULE_LICENSE("GPL");
1229 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
1230 MODULE_DESCRIPTION("S3C24XX MTD NAND driver");
1231