xref: /openbmc/linux/drivers/mtd/nand/raw/s3c2410.c (revision 6db6b729)
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  * @mtd: The MTD instance to pass to the MTD layer.
109  * @chip: The NAND chip information.
110  * @set: The platform information supplied for this set of NAND chips.
111  * @info: Link back to the hardware information.
112 */
113 struct s3c2410_nand_mtd {
114 	struct nand_chip		chip;
115 	struct s3c2410_nand_set		*set;
116 	struct s3c2410_nand_info	*info;
117 };
118 
119 enum s3c_cpu_type {
120 	TYPE_S3C2410,
121 	TYPE_S3C2412,
122 	TYPE_S3C2440,
123 };
124 
125 enum s3c_nand_clk_state {
126 	CLOCK_DISABLE	= 0,
127 	CLOCK_ENABLE,
128 	CLOCK_SUSPEND,
129 };
130 
131 /* overview of the s3c2410 nand state */
132 
133 /**
134  * struct s3c2410_nand_info - NAND controller state.
135  * @controller: Base controller structure.
136  * @mtds: An array of MTD instances on this controller.
137  * @platform: The platform data for this board.
138  * @device: The platform device we bound to.
139  * @clk: The clock resource for this controller.
140  * @regs: The area mapped for the hardware registers.
141  * @sel_reg: Pointer to the register controlling the NAND selection.
142  * @sel_bit: The bit in @sel_reg to select the NAND chip.
143  * @mtd_count: The number of MTDs created from this controller.
144  * @save_sel: The contents of @sel_reg to be saved over suspend.
145  * @clk_rate: The clock rate from @clk.
146  * @clk_state: The current clock state.
147  * @cpu_type: The exact type of this controller.
148  * @freq_transition: CPUFreq notifier block
149  */
150 struct s3c2410_nand_info {
151 	/* mtd info */
152 	struct nand_controller		controller;
153 	struct s3c2410_nand_mtd		*mtds;
154 	struct s3c2410_platform_nand	*platform;
155 
156 	/* device info */
157 	struct device			*device;
158 	struct clk			*clk;
159 	void __iomem			*regs;
160 	void __iomem			*sel_reg;
161 	int				sel_bit;
162 	int				mtd_count;
163 	unsigned long			save_sel;
164 	unsigned long			clk_rate;
165 	enum s3c_nand_clk_state		clk_state;
166 
167 	enum s3c_cpu_type		cpu_type;
168 };
169 
170 struct s3c24XX_nand_devtype_data {
171 	enum s3c_cpu_type type;
172 };
173 
174 static const struct s3c24XX_nand_devtype_data s3c2410_nand_devtype_data = {
175 	.type = TYPE_S3C2410,
176 };
177 
178 static const struct s3c24XX_nand_devtype_data s3c2412_nand_devtype_data = {
179 	.type = TYPE_S3C2412,
180 };
181 
182 static const struct s3c24XX_nand_devtype_data s3c2440_nand_devtype_data = {
183 	.type = TYPE_S3C2440,
184 };
185 
186 /* conversion functions */
187 
188 static struct s3c2410_nand_mtd *s3c2410_nand_mtd_toours(struct mtd_info *mtd)
189 {
190 	return container_of(mtd_to_nand(mtd), struct s3c2410_nand_mtd,
191 			    chip);
192 }
193 
194 static struct s3c2410_nand_info *s3c2410_nand_mtd_toinfo(struct mtd_info *mtd)
195 {
196 	return s3c2410_nand_mtd_toours(mtd)->info;
197 }
198 
199 static struct s3c2410_nand_info *to_nand_info(struct platform_device *dev)
200 {
201 	return platform_get_drvdata(dev);
202 }
203 
204 static struct s3c2410_platform_nand *to_nand_plat(struct platform_device *dev)
205 {
206 	return dev_get_platdata(&dev->dev);
207 }
208 
209 static inline int allow_clk_suspend(struct s3c2410_nand_info *info)
210 {
211 #ifdef CONFIG_MTD_NAND_S3C2410_CLKSTOP
212 	return 1;
213 #else
214 	return 0;
215 #endif
216 }
217 
218 /**
219  * s3c2410_nand_clk_set_state - Enable, disable or suspend NAND clock.
220  * @info: The controller instance.
221  * @new_state: State to which clock should be set.
222  */
223 static void s3c2410_nand_clk_set_state(struct s3c2410_nand_info *info,
224 		enum s3c_nand_clk_state new_state)
225 {
226 	if (!allow_clk_suspend(info) && new_state == CLOCK_SUSPEND)
227 		return;
228 
229 	if (info->clk_state == CLOCK_ENABLE) {
230 		if (new_state != CLOCK_ENABLE)
231 			clk_disable_unprepare(info->clk);
232 	} else {
233 		if (new_state == CLOCK_ENABLE)
234 			clk_prepare_enable(info->clk);
235 	}
236 
237 	info->clk_state = new_state;
238 }
239 
240 /* timing calculations */
241 
242 #define NS_IN_KHZ 1000000
243 
244 /**
245  * s3c_nand_calc_rate - calculate timing data.
246  * @wanted: The cycle time in nanoseconds.
247  * @clk: The clock rate in kHz.
248  * @max: The maximum divider value.
249  *
250  * Calculate the timing value from the given parameters.
251  */
252 static int s3c_nand_calc_rate(int wanted, unsigned long clk, int max)
253 {
254 	int result;
255 
256 	result = DIV_ROUND_UP((wanted * clk), NS_IN_KHZ);
257 
258 	pr_debug("result %d from %ld, %d\n", result, clk, wanted);
259 
260 	if (result > max) {
261 		pr_err("%d ns is too big for current clock rate %ld\n",
262 			wanted, clk);
263 		return -1;
264 	}
265 
266 	if (result < 1)
267 		result = 1;
268 
269 	return result;
270 }
271 
272 #define to_ns(ticks, clk) (((ticks) * NS_IN_KHZ) / (unsigned int)(clk))
273 
274 /* controller setup */
275 
276 /**
277  * s3c2410_nand_setrate - setup controller timing information.
278  * @info: The controller instance.
279  *
280  * Given the information supplied by the platform, calculate and set
281  * the necessary timing registers in the hardware to generate the
282  * necessary timing cycles to the hardware.
283  */
284 static int s3c2410_nand_setrate(struct s3c2410_nand_info *info)
285 {
286 	struct s3c2410_platform_nand *plat = info->platform;
287 	int tacls_max = (info->cpu_type == TYPE_S3C2412) ? 8 : 4;
288 	int tacls, twrph0, twrph1;
289 	unsigned long clkrate = clk_get_rate(info->clk);
290 	unsigned long set, cfg, mask;
291 	unsigned long flags;
292 
293 	/* calculate the timing information for the controller */
294 
295 	info->clk_rate = clkrate;
296 	clkrate /= 1000;	/* turn clock into kHz for ease of use */
297 
298 	if (plat != NULL) {
299 		tacls = s3c_nand_calc_rate(plat->tacls, clkrate, tacls_max);
300 		twrph0 = s3c_nand_calc_rate(plat->twrph0, clkrate, 8);
301 		twrph1 = s3c_nand_calc_rate(plat->twrph1, clkrate, 8);
302 	} else {
303 		/* default timings */
304 		tacls = tacls_max;
305 		twrph0 = 8;
306 		twrph1 = 8;
307 	}
308 
309 	if (tacls < 0 || twrph0 < 0 || twrph1 < 0) {
310 		dev_err(info->device, "cannot get suitable timings\n");
311 		return -EINVAL;
312 	}
313 
314 	dev_info(info->device, "Tacls=%d, %dns Twrph0=%d %dns, Twrph1=%d %dns\n",
315 		tacls, to_ns(tacls, clkrate), twrph0, to_ns(twrph0, clkrate),
316 						twrph1, to_ns(twrph1, clkrate));
317 
318 	switch (info->cpu_type) {
319 	case TYPE_S3C2410:
320 		mask = (S3C2410_NFCONF_TACLS(3) |
321 			S3C2410_NFCONF_TWRPH0(7) |
322 			S3C2410_NFCONF_TWRPH1(7));
323 		set = S3C2410_NFCONF_EN;
324 		set |= S3C2410_NFCONF_TACLS(tacls - 1);
325 		set |= S3C2410_NFCONF_TWRPH0(twrph0 - 1);
326 		set |= S3C2410_NFCONF_TWRPH1(twrph1 - 1);
327 		break;
328 
329 	case TYPE_S3C2440:
330 	case TYPE_S3C2412:
331 		mask = (S3C2440_NFCONF_TACLS(tacls_max - 1) |
332 			S3C2440_NFCONF_TWRPH0(7) |
333 			S3C2440_NFCONF_TWRPH1(7));
334 
335 		set = S3C2440_NFCONF_TACLS(tacls - 1);
336 		set |= S3C2440_NFCONF_TWRPH0(twrph0 - 1);
337 		set |= S3C2440_NFCONF_TWRPH1(twrph1 - 1);
338 		break;
339 
340 	default:
341 		BUG();
342 	}
343 
344 	local_irq_save(flags);
345 
346 	cfg = readl(info->regs + S3C2410_NFCONF);
347 	cfg &= ~mask;
348 	cfg |= set;
349 	writel(cfg, info->regs + S3C2410_NFCONF);
350 
351 	local_irq_restore(flags);
352 
353 	dev_dbg(info->device, "NF_CONF is 0x%lx\n", cfg);
354 
355 	return 0;
356 }
357 
358 /**
359  * s3c2410_nand_inithw - basic hardware initialisation
360  * @info: The hardware state.
361  *
362  * Do the basic initialisation of the hardware, using s3c2410_nand_setrate()
363  * to setup the hardware access speeds and set the controller to be enabled.
364 */
365 static int s3c2410_nand_inithw(struct s3c2410_nand_info *info)
366 {
367 	int ret;
368 
369 	ret = s3c2410_nand_setrate(info);
370 	if (ret < 0)
371 		return ret;
372 
373 	switch (info->cpu_type) {
374 	case TYPE_S3C2410:
375 	default:
376 		break;
377 
378 	case TYPE_S3C2440:
379 	case TYPE_S3C2412:
380 		/* enable the controller and de-assert nFCE */
381 
382 		writel(S3C2440_NFCONT_ENABLE, info->regs + S3C2440_NFCONT);
383 	}
384 
385 	return 0;
386 }
387 
388 /**
389  * s3c2410_nand_select_chip - select the given nand chip
390  * @this: NAND chip object.
391  * @chip: The chip number.
392  *
393  * This is called by the MTD layer to either select a given chip for the
394  * @mtd instance, or to indicate that the access has finished and the
395  * chip can be de-selected.
396  *
397  * The routine ensures that the nFCE line is correctly setup, and any
398  * platform specific selection code is called to route nFCE to the specific
399  * chip.
400  */
401 static void s3c2410_nand_select_chip(struct nand_chip *this, int chip)
402 {
403 	struct s3c2410_nand_info *info;
404 	struct s3c2410_nand_mtd *nmtd;
405 	unsigned long cur;
406 
407 	nmtd = nand_get_controller_data(this);
408 	info = nmtd->info;
409 
410 	if (chip != -1)
411 		s3c2410_nand_clk_set_state(info, CLOCK_ENABLE);
412 
413 	cur = readl(info->sel_reg);
414 
415 	if (chip == -1) {
416 		cur |= info->sel_bit;
417 	} else {
418 		if (nmtd->set != NULL && chip > nmtd->set->nr_chips) {
419 			dev_err(info->device, "invalid chip %d\n", chip);
420 			return;
421 		}
422 
423 		if (info->platform != NULL) {
424 			if (info->platform->select_chip != NULL)
425 				(info->platform->select_chip) (nmtd->set, chip);
426 		}
427 
428 		cur &= ~info->sel_bit;
429 	}
430 
431 	writel(cur, info->sel_reg);
432 
433 	if (chip == -1)
434 		s3c2410_nand_clk_set_state(info, CLOCK_SUSPEND);
435 }
436 
437 /* s3c2410_nand_hwcontrol
438  *
439  * Issue command and address cycles to the chip
440 */
441 
442 static void s3c2410_nand_hwcontrol(struct nand_chip *chip, int cmd,
443 				   unsigned int ctrl)
444 {
445 	struct mtd_info *mtd = nand_to_mtd(chip);
446 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
447 
448 	if (cmd == NAND_CMD_NONE)
449 		return;
450 
451 	if (ctrl & NAND_CLE)
452 		writeb(cmd, info->regs + S3C2410_NFCMD);
453 	else
454 		writeb(cmd, info->regs + S3C2410_NFADDR);
455 }
456 
457 /* command and control functions */
458 
459 static void s3c2440_nand_hwcontrol(struct nand_chip *chip, int cmd,
460 				   unsigned int ctrl)
461 {
462 	struct mtd_info *mtd = nand_to_mtd(chip);
463 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
464 
465 	if (cmd == NAND_CMD_NONE)
466 		return;
467 
468 	if (ctrl & NAND_CLE)
469 		writeb(cmd, info->regs + S3C2440_NFCMD);
470 	else
471 		writeb(cmd, info->regs + S3C2440_NFADDR);
472 }
473 
474 /* s3c2410_nand_devready()
475  *
476  * returns 0 if the nand is busy, 1 if it is ready
477 */
478 
479 static int s3c2410_nand_devready(struct nand_chip *chip)
480 {
481 	struct mtd_info *mtd = nand_to_mtd(chip);
482 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
483 	return readb(info->regs + S3C2410_NFSTAT) & S3C2410_NFSTAT_BUSY;
484 }
485 
486 static int s3c2440_nand_devready(struct nand_chip *chip)
487 {
488 	struct mtd_info *mtd = nand_to_mtd(chip);
489 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
490 	return readb(info->regs + S3C2440_NFSTAT) & S3C2440_NFSTAT_READY;
491 }
492 
493 static int s3c2412_nand_devready(struct nand_chip *chip)
494 {
495 	struct mtd_info *mtd = nand_to_mtd(chip);
496 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
497 	return readb(info->regs + S3C2412_NFSTAT) & S3C2412_NFSTAT_READY;
498 }
499 
500 /* ECC handling functions */
501 
502 static int s3c2410_nand_correct_data(struct nand_chip *chip, u_char *dat,
503 				     u_char *read_ecc, u_char *calc_ecc)
504 {
505 	struct mtd_info *mtd = nand_to_mtd(chip);
506 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
507 	unsigned int diff0, diff1, diff2;
508 	unsigned int bit, byte;
509 
510 	pr_debug("%s(%p,%p,%p,%p)\n", __func__, mtd, dat, read_ecc, calc_ecc);
511 
512 	diff0 = read_ecc[0] ^ calc_ecc[0];
513 	diff1 = read_ecc[1] ^ calc_ecc[1];
514 	diff2 = read_ecc[2] ^ calc_ecc[2];
515 
516 	pr_debug("%s: rd %*phN calc %*phN diff %02x%02x%02x\n",
517 		 __func__, 3, read_ecc, 3, calc_ecc,
518 		 diff0, diff1, diff2);
519 
520 	if (diff0 == 0 && diff1 == 0 && diff2 == 0)
521 		return 0;		/* ECC is ok */
522 
523 	/* sometimes people do not think about using the ECC, so check
524 	 * to see if we have an 0xff,0xff,0xff read ECC and then ignore
525 	 * the error, on the assumption that this is an un-eccd page.
526 	 */
527 	if (read_ecc[0] == 0xff && read_ecc[1] == 0xff && read_ecc[2] == 0xff
528 	    && info->platform->ignore_unset_ecc)
529 		return 0;
530 
531 	/* Can we correct this ECC (ie, one row and column change).
532 	 * Note, this is similar to the 256 error code on smartmedia */
533 
534 	if (((diff0 ^ (diff0 >> 1)) & 0x55) == 0x55 &&
535 	    ((diff1 ^ (diff1 >> 1)) & 0x55) == 0x55 &&
536 	    ((diff2 ^ (diff2 >> 1)) & 0x55) == 0x55) {
537 		/* calculate the bit position of the error */
538 
539 		bit  = ((diff2 >> 3) & 1) |
540 		       ((diff2 >> 4) & 2) |
541 		       ((diff2 >> 5) & 4);
542 
543 		/* calculate the byte position of the error */
544 
545 		byte = ((diff2 << 7) & 0x100) |
546 		       ((diff1 << 0) & 0x80)  |
547 		       ((diff1 << 1) & 0x40)  |
548 		       ((diff1 << 2) & 0x20)  |
549 		       ((diff1 << 3) & 0x10)  |
550 		       ((diff0 >> 4) & 0x08)  |
551 		       ((diff0 >> 3) & 0x04)  |
552 		       ((diff0 >> 2) & 0x02)  |
553 		       ((diff0 >> 1) & 0x01);
554 
555 		dev_dbg(info->device, "correcting error bit %d, byte %d\n",
556 			bit, byte);
557 
558 		dat[byte] ^= (1 << bit);
559 		return 1;
560 	}
561 
562 	/* if there is only one bit difference in the ECC, then
563 	 * one of only a row or column parity has changed, which
564 	 * means the error is most probably in the ECC itself */
565 
566 	diff0 |= (diff1 << 8);
567 	diff0 |= (diff2 << 16);
568 
569 	/* equal to "(diff0 & ~(1 << __ffs(diff0)))" */
570 	if ((diff0 & (diff0 - 1)) == 0)
571 		return 1;
572 
573 	return -1;
574 }
575 
576 /* ECC functions
577  *
578  * These allow the s3c2410 and s3c2440 to use the controller's ECC
579  * generator block to ECC the data as it passes through]
580 */
581 
582 static void s3c2410_nand_enable_hwecc(struct nand_chip *chip, int mode)
583 {
584 	struct s3c2410_nand_info *info;
585 	unsigned long ctrl;
586 
587 	info = s3c2410_nand_mtd_toinfo(nand_to_mtd(chip));
588 	ctrl = readl(info->regs + S3C2410_NFCONF);
589 	ctrl |= S3C2410_NFCONF_INITECC;
590 	writel(ctrl, info->regs + S3C2410_NFCONF);
591 }
592 
593 static void s3c2412_nand_enable_hwecc(struct nand_chip *chip, int mode)
594 {
595 	struct s3c2410_nand_info *info;
596 	unsigned long ctrl;
597 
598 	info = s3c2410_nand_mtd_toinfo(nand_to_mtd(chip));
599 	ctrl = readl(info->regs + S3C2440_NFCONT);
600 	writel(ctrl | S3C2412_NFCONT_INIT_MAIN_ECC,
601 	       info->regs + S3C2440_NFCONT);
602 }
603 
604 static void s3c2440_nand_enable_hwecc(struct nand_chip *chip, int mode)
605 {
606 	struct s3c2410_nand_info *info;
607 	unsigned long ctrl;
608 
609 	info = s3c2410_nand_mtd_toinfo(nand_to_mtd(chip));
610 	ctrl = readl(info->regs + S3C2440_NFCONT);
611 	writel(ctrl | S3C2440_NFCONT_INITECC, info->regs + S3C2440_NFCONT);
612 }
613 
614 static int s3c2410_nand_calculate_ecc(struct nand_chip *chip,
615 				      const u_char *dat, u_char *ecc_code)
616 {
617 	struct mtd_info *mtd = nand_to_mtd(chip);
618 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
619 
620 	ecc_code[0] = readb(info->regs + S3C2410_NFECC + 0);
621 	ecc_code[1] = readb(info->regs + S3C2410_NFECC + 1);
622 	ecc_code[2] = readb(info->regs + S3C2410_NFECC + 2);
623 
624 	pr_debug("%s: returning ecc %*phN\n", __func__, 3, ecc_code);
625 
626 	return 0;
627 }
628 
629 static int s3c2412_nand_calculate_ecc(struct nand_chip *chip,
630 				      const u_char *dat, u_char *ecc_code)
631 {
632 	struct mtd_info *mtd = nand_to_mtd(chip);
633 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
634 	unsigned long ecc = readl(info->regs + S3C2412_NFMECC0);
635 
636 	ecc_code[0] = ecc;
637 	ecc_code[1] = ecc >> 8;
638 	ecc_code[2] = ecc >> 16;
639 
640 	pr_debug("%s: returning ecc %*phN\n", __func__, 3, ecc_code);
641 
642 	return 0;
643 }
644 
645 static int s3c2440_nand_calculate_ecc(struct nand_chip *chip,
646 				      const u_char *dat, u_char *ecc_code)
647 {
648 	struct mtd_info *mtd = nand_to_mtd(chip);
649 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
650 	unsigned long ecc = readl(info->regs + S3C2440_NFMECC0);
651 
652 	ecc_code[0] = ecc;
653 	ecc_code[1] = ecc >> 8;
654 	ecc_code[2] = ecc >> 16;
655 
656 	pr_debug("%s: returning ecc %06lx\n", __func__, ecc & 0xffffff);
657 
658 	return 0;
659 }
660 
661 /* over-ride the standard functions for a little more speed. We can
662  * use read/write block to move the data buffers to/from the controller
663 */
664 
665 static void s3c2410_nand_read_buf(struct nand_chip *this, u_char *buf, int len)
666 {
667 	readsb(this->legacy.IO_ADDR_R, buf, len);
668 }
669 
670 static void s3c2440_nand_read_buf(struct nand_chip *this, u_char *buf, int len)
671 {
672 	struct mtd_info *mtd = nand_to_mtd(this);
673 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
674 
675 	readsl(info->regs + S3C2440_NFDATA, buf, len >> 2);
676 
677 	/* cleanup if we've got less than a word to do */
678 	if (len & 3) {
679 		buf += len & ~3;
680 
681 		for (; len & 3; len--)
682 			*buf++ = readb(info->regs + S3C2440_NFDATA);
683 	}
684 }
685 
686 static void s3c2410_nand_write_buf(struct nand_chip *this, const u_char *buf,
687 				   int len)
688 {
689 	writesb(this->legacy.IO_ADDR_W, buf, len);
690 }
691 
692 static void s3c2440_nand_write_buf(struct nand_chip *this, const u_char *buf,
693 				   int len)
694 {
695 	struct mtd_info *mtd = nand_to_mtd(this);
696 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
697 
698 	writesl(info->regs + S3C2440_NFDATA, buf, len >> 2);
699 
700 	/* cleanup any fractional write */
701 	if (len & 3) {
702 		buf += len & ~3;
703 
704 		for (; len & 3; len--, buf++)
705 			writeb(*buf, info->regs + S3C2440_NFDATA);
706 	}
707 }
708 
709 /* device management functions */
710 
711 static void s3c24xx_nand_remove(struct platform_device *pdev)
712 {
713 	struct s3c2410_nand_info *info = to_nand_info(pdev);
714 
715 	if (info == NULL)
716 		return;
717 
718 	/* Release all our mtds  and their partitions, then go through
719 	 * freeing the resources used
720 	 */
721 
722 	if (info->mtds != NULL) {
723 		struct s3c2410_nand_mtd *ptr = info->mtds;
724 		int mtdno;
725 
726 		for (mtdno = 0; mtdno < info->mtd_count; mtdno++, ptr++) {
727 			pr_debug("releasing mtd %d (%p)\n", mtdno, ptr);
728 			WARN_ON(mtd_device_unregister(nand_to_mtd(&ptr->chip)));
729 			nand_cleanup(&ptr->chip);
730 		}
731 	}
732 
733 	/* free the common resources */
734 
735 	if (!IS_ERR(info->clk))
736 		s3c2410_nand_clk_set_state(info, CLOCK_DISABLE);
737 }
738 
739 static int s3c2410_nand_add_partition(struct s3c2410_nand_info *info,
740 				      struct s3c2410_nand_mtd *mtd,
741 				      struct s3c2410_nand_set *set)
742 {
743 	if (set) {
744 		struct mtd_info *mtdinfo = nand_to_mtd(&mtd->chip);
745 
746 		mtdinfo->name = set->name;
747 
748 		return mtd_device_register(mtdinfo, set->partitions,
749 					   set->nr_partitions);
750 	}
751 
752 	return -ENODEV;
753 }
754 
755 static int s3c2410_nand_setup_interface(struct nand_chip *chip, int csline,
756 					const struct nand_interface_config *conf)
757 {
758 	struct mtd_info *mtd = nand_to_mtd(chip);
759 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
760 	struct s3c2410_platform_nand *pdata = info->platform;
761 	const struct nand_sdr_timings *timings;
762 	int tacls;
763 
764 	timings = nand_get_sdr_timings(conf);
765 	if (IS_ERR(timings))
766 		return -ENOTSUPP;
767 
768 	tacls = timings->tCLS_min - timings->tWP_min;
769 	if (tacls < 0)
770 		tacls = 0;
771 
772 	pdata->tacls  = DIV_ROUND_UP(tacls, 1000);
773 	pdata->twrph0 = DIV_ROUND_UP(timings->tWP_min, 1000);
774 	pdata->twrph1 = DIV_ROUND_UP(timings->tCLH_min, 1000);
775 
776 	return s3c2410_nand_setrate(info);
777 }
778 
779 /**
780  * s3c2410_nand_init_chip - initialise a single instance of an chip
781  * @info: The base NAND controller the chip is on.
782  * @nmtd: The new controller MTD instance to fill in.
783  * @set: The information passed from the board specific platform data.
784  *
785  * Initialise the given @nmtd from the information in @info and @set. This
786  * readies the structure for use with the MTD layer functions by ensuring
787  * all pointers are setup and the necessary control routines selected.
788  */
789 static void s3c2410_nand_init_chip(struct s3c2410_nand_info *info,
790 				   struct s3c2410_nand_mtd *nmtd,
791 				   struct s3c2410_nand_set *set)
792 {
793 	struct device_node *np = info->device->of_node;
794 	struct nand_chip *chip = &nmtd->chip;
795 	void __iomem *regs = info->regs;
796 
797 	nand_set_flash_node(chip, set->of_node);
798 
799 	chip->legacy.write_buf    = s3c2410_nand_write_buf;
800 	chip->legacy.read_buf     = s3c2410_nand_read_buf;
801 	chip->legacy.select_chip  = s3c2410_nand_select_chip;
802 	chip->legacy.chip_delay   = 50;
803 	nand_set_controller_data(chip, nmtd);
804 	chip->options	   = set->options;
805 	chip->controller   = &info->controller;
806 
807 	/*
808 	 * let's keep behavior unchanged for legacy boards booting via pdata and
809 	 * auto-detect timings only when booting with a device tree.
810 	 */
811 	if (!np)
812 		chip->options |= NAND_KEEP_TIMINGS;
813 
814 	switch (info->cpu_type) {
815 	case TYPE_S3C2410:
816 		chip->legacy.IO_ADDR_W = regs + S3C2410_NFDATA;
817 		info->sel_reg   = regs + S3C2410_NFCONF;
818 		info->sel_bit	= S3C2410_NFCONF_nFCE;
819 		chip->legacy.cmd_ctrl  = s3c2410_nand_hwcontrol;
820 		chip->legacy.dev_ready = s3c2410_nand_devready;
821 		break;
822 
823 	case TYPE_S3C2440:
824 		chip->legacy.IO_ADDR_W = regs + S3C2440_NFDATA;
825 		info->sel_reg   = regs + S3C2440_NFCONT;
826 		info->sel_bit	= S3C2440_NFCONT_nFCE;
827 		chip->legacy.cmd_ctrl  = s3c2440_nand_hwcontrol;
828 		chip->legacy.dev_ready = s3c2440_nand_devready;
829 		chip->legacy.read_buf  = s3c2440_nand_read_buf;
830 		chip->legacy.write_buf	= s3c2440_nand_write_buf;
831 		break;
832 
833 	case TYPE_S3C2412:
834 		chip->legacy.IO_ADDR_W = regs + S3C2440_NFDATA;
835 		info->sel_reg   = regs + S3C2440_NFCONT;
836 		info->sel_bit	= S3C2412_NFCONT_nFCE0;
837 		chip->legacy.cmd_ctrl  = s3c2440_nand_hwcontrol;
838 		chip->legacy.dev_ready = s3c2412_nand_devready;
839 
840 		if (readl(regs + S3C2410_NFCONF) & S3C2412_NFCONF_NANDBOOT)
841 			dev_info(info->device, "System booted from NAND\n");
842 
843 		break;
844 	}
845 
846 	chip->legacy.IO_ADDR_R = chip->legacy.IO_ADDR_W;
847 
848 	nmtd->info	   = info;
849 	nmtd->set	   = set;
850 
851 	chip->ecc.engine_type = info->platform->engine_type;
852 
853 	/*
854 	 * If you use u-boot BBT creation code, specifying this flag will
855 	 * let the kernel fish out the BBT from the NAND.
856 	 */
857 	if (set->flash_bbt)
858 		chip->bbt_options |= NAND_BBT_USE_FLASH;
859 }
860 
861 /**
862  * s3c2410_nand_attach_chip - Init the ECC engine after NAND scan
863  * @chip: The NAND chip
864  *
865  * This hook is called by the core after the identification of the NAND chip,
866  * once the relevant per-chip information is up to date.. This call ensure that
867  * we update the internal state accordingly.
868  *
869  * The internal state is currently limited to the ECC state information.
870 */
871 static int s3c2410_nand_attach_chip(struct nand_chip *chip)
872 {
873 	struct mtd_info *mtd = nand_to_mtd(chip);
874 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
875 
876 	switch (chip->ecc.engine_type) {
877 
878 	case NAND_ECC_ENGINE_TYPE_NONE:
879 		dev_info(info->device, "ECC disabled\n");
880 		break;
881 
882 	case NAND_ECC_ENGINE_TYPE_SOFT:
883 		/*
884 		 * This driver expects Hamming based ECC when engine_type is set
885 		 * to NAND_ECC_ENGINE_TYPE_SOFT. Force ecc.algo to
886 		 * NAND_ECC_ALGO_HAMMING to avoid adding an extra ecc_algo field
887 		 * to s3c2410_platform_nand.
888 		 */
889 		chip->ecc.algo = NAND_ECC_ALGO_HAMMING;
890 		dev_info(info->device, "soft ECC\n");
891 		break;
892 
893 	case NAND_ECC_ENGINE_TYPE_ON_HOST:
894 		chip->ecc.calculate = s3c2410_nand_calculate_ecc;
895 		chip->ecc.correct   = s3c2410_nand_correct_data;
896 		chip->ecc.strength  = 1;
897 
898 		switch (info->cpu_type) {
899 		case TYPE_S3C2410:
900 			chip->ecc.hwctl	    = s3c2410_nand_enable_hwecc;
901 			chip->ecc.calculate = s3c2410_nand_calculate_ecc;
902 			break;
903 
904 		case TYPE_S3C2412:
905 			chip->ecc.hwctl     = s3c2412_nand_enable_hwecc;
906 			chip->ecc.calculate = s3c2412_nand_calculate_ecc;
907 			break;
908 
909 		case TYPE_S3C2440:
910 			chip->ecc.hwctl     = s3c2440_nand_enable_hwecc;
911 			chip->ecc.calculate = s3c2440_nand_calculate_ecc;
912 			break;
913 		}
914 
915 		dev_dbg(info->device, "chip %p => page shift %d\n",
916 			chip, chip->page_shift);
917 
918 		/* change the behaviour depending on whether we are using
919 		 * the large or small page nand device */
920 		if (chip->page_shift > 10) {
921 			chip->ecc.size	    = 256;
922 			chip->ecc.bytes	    = 3;
923 		} else {
924 			chip->ecc.size	    = 512;
925 			chip->ecc.bytes	    = 3;
926 			mtd_set_ooblayout(nand_to_mtd(chip),
927 					  &s3c2410_ooblayout_ops);
928 		}
929 
930 		dev_info(info->device, "hardware ECC\n");
931 		break;
932 
933 	default:
934 		dev_err(info->device, "invalid ECC mode!\n");
935 		return -EINVAL;
936 	}
937 
938 	if (chip->bbt_options & NAND_BBT_USE_FLASH)
939 		chip->options |= NAND_SKIP_BBTSCAN;
940 
941 	return 0;
942 }
943 
944 static const struct nand_controller_ops s3c24xx_nand_controller_ops = {
945 	.attach_chip = s3c2410_nand_attach_chip,
946 	.setup_interface = s3c2410_nand_setup_interface,
947 };
948 
949 static const struct of_device_id s3c24xx_nand_dt_ids[] = {
950 	{
951 		.compatible = "samsung,s3c2410-nand",
952 		.data = &s3c2410_nand_devtype_data,
953 	}, {
954 		/* also compatible with s3c6400 */
955 		.compatible = "samsung,s3c2412-nand",
956 		.data = &s3c2412_nand_devtype_data,
957 	}, {
958 		.compatible = "samsung,s3c2440-nand",
959 		.data = &s3c2440_nand_devtype_data,
960 	},
961 	{ /* sentinel */ }
962 };
963 MODULE_DEVICE_TABLE(of, s3c24xx_nand_dt_ids);
964 
965 static int s3c24xx_nand_probe_dt(struct platform_device *pdev)
966 {
967 	const struct s3c24XX_nand_devtype_data *devtype_data;
968 	struct s3c2410_platform_nand *pdata;
969 	struct s3c2410_nand_info *info = platform_get_drvdata(pdev);
970 	struct device_node *np = pdev->dev.of_node, *child;
971 	struct s3c2410_nand_set *sets;
972 
973 	devtype_data = of_device_get_match_data(&pdev->dev);
974 	if (!devtype_data)
975 		return -ENODEV;
976 
977 	info->cpu_type = devtype_data->type;
978 
979 	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
980 	if (!pdata)
981 		return -ENOMEM;
982 
983 	pdev->dev.platform_data = pdata;
984 
985 	pdata->nr_sets = of_get_child_count(np);
986 	if (!pdata->nr_sets)
987 		return 0;
988 
989 	sets = devm_kcalloc(&pdev->dev, pdata->nr_sets, sizeof(*sets),
990 			    GFP_KERNEL);
991 	if (!sets)
992 		return -ENOMEM;
993 
994 	pdata->sets = sets;
995 
996 	for_each_available_child_of_node(np, child) {
997 		sets->name = (char *)child->name;
998 		sets->of_node = child;
999 		sets->nr_chips = 1;
1000 
1001 		of_node_get(child);
1002 
1003 		sets++;
1004 	}
1005 
1006 	return 0;
1007 }
1008 
1009 static int s3c24xx_nand_probe_pdata(struct platform_device *pdev)
1010 {
1011 	struct s3c2410_nand_info *info = platform_get_drvdata(pdev);
1012 
1013 	info->cpu_type = platform_get_device_id(pdev)->driver_data;
1014 
1015 	return 0;
1016 }
1017 
1018 /* s3c24xx_nand_probe
1019  *
1020  * called by device layer when it finds a device matching
1021  * one our driver can handled. This code checks to see if
1022  * it can allocate all necessary resources then calls the
1023  * nand layer to look for devices
1024 */
1025 static int s3c24xx_nand_probe(struct platform_device *pdev)
1026 {
1027 	struct s3c2410_platform_nand *plat;
1028 	struct s3c2410_nand_info *info;
1029 	struct s3c2410_nand_mtd *nmtd;
1030 	struct s3c2410_nand_set *sets;
1031 	struct resource *res;
1032 	int err = 0;
1033 	int size;
1034 	int nr_sets;
1035 	int setno;
1036 
1037 	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
1038 	if (info == NULL) {
1039 		err = -ENOMEM;
1040 		goto exit_error;
1041 	}
1042 
1043 	platform_set_drvdata(pdev, info);
1044 
1045 	nand_controller_init(&info->controller);
1046 	info->controller.ops = &s3c24xx_nand_controller_ops;
1047 
1048 	/* get the clock source and enable it */
1049 
1050 	info->clk = devm_clk_get(&pdev->dev, "nand");
1051 	if (IS_ERR(info->clk)) {
1052 		dev_err(&pdev->dev, "failed to get clock\n");
1053 		err = -ENOENT;
1054 		goto exit_error;
1055 	}
1056 
1057 	s3c2410_nand_clk_set_state(info, CLOCK_ENABLE);
1058 
1059 	if (pdev->dev.of_node)
1060 		err = s3c24xx_nand_probe_dt(pdev);
1061 	else
1062 		err = s3c24xx_nand_probe_pdata(pdev);
1063 
1064 	if (err)
1065 		goto exit_error;
1066 
1067 	plat = to_nand_plat(pdev);
1068 
1069 	/* allocate and map the resource */
1070 
1071 	/* currently we assume we have the one resource */
1072 	res = pdev->resource;
1073 	size = resource_size(res);
1074 
1075 	info->device	= &pdev->dev;
1076 	info->platform	= plat;
1077 
1078 	info->regs = devm_ioremap_resource(&pdev->dev, res);
1079 	if (IS_ERR(info->regs)) {
1080 		err = PTR_ERR(info->regs);
1081 		goto exit_error;
1082 	}
1083 
1084 	dev_dbg(&pdev->dev, "mapped registers at %p\n", info->regs);
1085 
1086 	if (!plat->sets || plat->nr_sets < 1) {
1087 		err = -EINVAL;
1088 		goto exit_error;
1089 	}
1090 
1091 	sets = plat->sets;
1092 	nr_sets = plat->nr_sets;
1093 
1094 	info->mtd_count = nr_sets;
1095 
1096 	/* allocate our information */
1097 
1098 	size = nr_sets * sizeof(*info->mtds);
1099 	info->mtds = devm_kzalloc(&pdev->dev, size, GFP_KERNEL);
1100 	if (info->mtds == NULL) {
1101 		err = -ENOMEM;
1102 		goto exit_error;
1103 	}
1104 
1105 	/* initialise all possible chips */
1106 
1107 	nmtd = info->mtds;
1108 
1109 	for (setno = 0; setno < nr_sets; setno++, nmtd++, sets++) {
1110 		struct mtd_info *mtd = nand_to_mtd(&nmtd->chip);
1111 
1112 		pr_debug("initialising set %d (%p, info %p)\n",
1113 			 setno, nmtd, info);
1114 
1115 		mtd->dev.parent = &pdev->dev;
1116 		s3c2410_nand_init_chip(info, nmtd, sets);
1117 
1118 		err = nand_scan(&nmtd->chip, sets ? sets->nr_chips : 1);
1119 		if (err)
1120 			goto exit_error;
1121 
1122 		s3c2410_nand_add_partition(info, nmtd, sets);
1123 	}
1124 
1125 	/* initialise the hardware */
1126 	err = s3c2410_nand_inithw(info);
1127 	if (err != 0)
1128 		goto exit_error;
1129 
1130 	if (allow_clk_suspend(info)) {
1131 		dev_info(&pdev->dev, "clock idle support enabled\n");
1132 		s3c2410_nand_clk_set_state(info, CLOCK_SUSPEND);
1133 	}
1134 
1135 	return 0;
1136 
1137  exit_error:
1138 	s3c24xx_nand_remove(pdev);
1139 
1140 	if (err == 0)
1141 		err = -EINVAL;
1142 	return err;
1143 }
1144 
1145 /* PM Support */
1146 #ifdef CONFIG_PM
1147 
1148 static int s3c24xx_nand_suspend(struct platform_device *dev, pm_message_t pm)
1149 {
1150 	struct s3c2410_nand_info *info = platform_get_drvdata(dev);
1151 
1152 	if (info) {
1153 		info->save_sel = readl(info->sel_reg);
1154 
1155 		/* For the moment, we must ensure nFCE is high during
1156 		 * the time we are suspended. This really should be
1157 		 * handled by suspending the MTDs we are using, but
1158 		 * that is currently not the case. */
1159 
1160 		writel(info->save_sel | info->sel_bit, info->sel_reg);
1161 
1162 		s3c2410_nand_clk_set_state(info, CLOCK_DISABLE);
1163 	}
1164 
1165 	return 0;
1166 }
1167 
1168 static int s3c24xx_nand_resume(struct platform_device *dev)
1169 {
1170 	struct s3c2410_nand_info *info = platform_get_drvdata(dev);
1171 	unsigned long sel;
1172 
1173 	if (info) {
1174 		s3c2410_nand_clk_set_state(info, CLOCK_ENABLE);
1175 		s3c2410_nand_inithw(info);
1176 
1177 		/* Restore the state of the nFCE line. */
1178 
1179 		sel = readl(info->sel_reg);
1180 		sel &= ~info->sel_bit;
1181 		sel |= info->save_sel & info->sel_bit;
1182 		writel(sel, info->sel_reg);
1183 
1184 		s3c2410_nand_clk_set_state(info, CLOCK_SUSPEND);
1185 	}
1186 
1187 	return 0;
1188 }
1189 
1190 #else
1191 #define s3c24xx_nand_suspend NULL
1192 #define s3c24xx_nand_resume NULL
1193 #endif
1194 
1195 /* driver device registration */
1196 
1197 static const struct platform_device_id s3c24xx_driver_ids[] = {
1198 	{
1199 		.name		= "s3c2410-nand",
1200 		.driver_data	= TYPE_S3C2410,
1201 	}, {
1202 		.name		= "s3c2440-nand",
1203 		.driver_data	= TYPE_S3C2440,
1204 	}, {
1205 		.name		= "s3c2412-nand",
1206 		.driver_data	= TYPE_S3C2412,
1207 	}, {
1208 		.name		= "s3c6400-nand",
1209 		.driver_data	= TYPE_S3C2412, /* compatible with 2412 */
1210 	},
1211 	{ }
1212 };
1213 
1214 MODULE_DEVICE_TABLE(platform, s3c24xx_driver_ids);
1215 
1216 static struct platform_driver s3c24xx_nand_driver = {
1217 	.probe		= s3c24xx_nand_probe,
1218 	.remove_new	= s3c24xx_nand_remove,
1219 	.suspend	= s3c24xx_nand_suspend,
1220 	.resume		= s3c24xx_nand_resume,
1221 	.id_table	= s3c24xx_driver_ids,
1222 	.driver		= {
1223 		.name	= "s3c24xx-nand",
1224 		.of_match_table = s3c24xx_nand_dt_ids,
1225 	},
1226 };
1227 
1228 module_platform_driver(s3c24xx_nand_driver);
1229 
1230 MODULE_LICENSE("GPL");
1231 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
1232 MODULE_DESCRIPTION("S3C24XX MTD NAND driver");
1233