xref: /openbmc/linux/drivers/mtd/nand/raw/mpc5121_nfc.c (revision 36acd5e2)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright 2004-2008 Freescale Semiconductor, Inc.
4  * Copyright 2009 Semihalf.
5  *
6  * Approved as OSADL project by a majority of OSADL members and funded
7  * by OSADL membership fees in 2009;  for details see www.osadl.org.
8  *
9  * Based on original driver from Freescale Semiconductor
10  * written by John Rigby <jrigby@freescale.com> on basis of mxc_nand.c.
11  * Reworked and extended by Piotr Ziecik <kosmo@semihalf.com>.
12  */
13 
14 #include <linux/module.h>
15 #include <linux/clk.h>
16 #include <linux/gfp.h>
17 #include <linux/delay.h>
18 #include <linux/err.h>
19 #include <linux/interrupt.h>
20 #include <linux/io.h>
21 #include <linux/mtd/mtd.h>
22 #include <linux/mtd/rawnand.h>
23 #include <linux/mtd/partitions.h>
24 #include <linux/of_address.h>
25 #include <linux/of_device.h>
26 #include <linux/of_irq.h>
27 #include <linux/of_platform.h>
28 
29 #include <asm/mpc5121.h>
30 
31 /* Addresses for NFC MAIN RAM BUFFER areas */
32 #define NFC_MAIN_AREA(n)	((n) *  0x200)
33 
34 /* Addresses for NFC SPARE BUFFER areas */
35 #define NFC_SPARE_BUFFERS	8
36 #define NFC_SPARE_LEN		0x40
37 #define NFC_SPARE_AREA(n)	(0x1000 + ((n) * NFC_SPARE_LEN))
38 
39 /* MPC5121 NFC registers */
40 #define NFC_BUF_ADDR		0x1E04
41 #define NFC_FLASH_ADDR		0x1E06
42 #define NFC_FLASH_CMD		0x1E08
43 #define NFC_CONFIG		0x1E0A
44 #define NFC_ECC_STATUS1		0x1E0C
45 #define NFC_ECC_STATUS2		0x1E0E
46 #define NFC_SPAS		0x1E10
47 #define NFC_WRPROT		0x1E12
48 #define NFC_NF_WRPRST		0x1E18
49 #define NFC_CONFIG1		0x1E1A
50 #define NFC_CONFIG2		0x1E1C
51 #define NFC_UNLOCKSTART_BLK0	0x1E20
52 #define NFC_UNLOCKEND_BLK0	0x1E22
53 #define NFC_UNLOCKSTART_BLK1	0x1E24
54 #define NFC_UNLOCKEND_BLK1	0x1E26
55 #define NFC_UNLOCKSTART_BLK2	0x1E28
56 #define NFC_UNLOCKEND_BLK2	0x1E2A
57 #define NFC_UNLOCKSTART_BLK3	0x1E2C
58 #define NFC_UNLOCKEND_BLK3	0x1E2E
59 
60 /* Bit Definitions: NFC_BUF_ADDR */
61 #define NFC_RBA_MASK		(7 << 0)
62 #define NFC_ACTIVE_CS_SHIFT	5
63 #define NFC_ACTIVE_CS_MASK	(3 << NFC_ACTIVE_CS_SHIFT)
64 
65 /* Bit Definitions: NFC_CONFIG */
66 #define NFC_BLS_UNLOCKED	(1 << 1)
67 
68 /* Bit Definitions: NFC_CONFIG1 */
69 #define NFC_ECC_4BIT		(1 << 0)
70 #define NFC_FULL_PAGE_DMA	(1 << 1)
71 #define NFC_SPARE_ONLY		(1 << 2)
72 #define NFC_ECC_ENABLE		(1 << 3)
73 #define NFC_INT_MASK		(1 << 4)
74 #define NFC_BIG_ENDIAN		(1 << 5)
75 #define NFC_RESET		(1 << 6)
76 #define NFC_CE			(1 << 7)
77 #define NFC_ONE_CYCLE		(1 << 8)
78 #define NFC_PPB_32		(0 << 9)
79 #define NFC_PPB_64		(1 << 9)
80 #define NFC_PPB_128		(2 << 9)
81 #define NFC_PPB_256		(3 << 9)
82 #define NFC_PPB_MASK		(3 << 9)
83 #define NFC_FULL_PAGE_INT	(1 << 11)
84 
85 /* Bit Definitions: NFC_CONFIG2 */
86 #define NFC_COMMAND		(1 << 0)
87 #define NFC_ADDRESS		(1 << 1)
88 #define NFC_INPUT		(1 << 2)
89 #define NFC_OUTPUT		(1 << 3)
90 #define NFC_ID			(1 << 4)
91 #define NFC_STATUS		(1 << 5)
92 #define NFC_CMD_FAIL		(1 << 15)
93 #define NFC_INT			(1 << 15)
94 
95 /* Bit Definitions: NFC_WRPROT */
96 #define NFC_WPC_LOCK_TIGHT	(1 << 0)
97 #define NFC_WPC_LOCK		(1 << 1)
98 #define NFC_WPC_UNLOCK		(1 << 2)
99 
100 #define	DRV_NAME		"mpc5121_nfc"
101 
102 /* Timeouts */
103 #define NFC_RESET_TIMEOUT	1000		/* 1 ms */
104 #define NFC_TIMEOUT		(HZ / 10)	/* 1/10 s */
105 
106 struct mpc5121_nfc_prv {
107 	struct nand_controller	controller;
108 	struct nand_chip	chip;
109 	int			irq;
110 	void __iomem		*regs;
111 	struct clk		*clk;
112 	wait_queue_head_t	irq_waitq;
113 	uint			column;
114 	int			spareonly;
115 	void __iomem		*csreg;
116 	struct device		*dev;
117 };
118 
119 static void mpc5121_nfc_done(struct mtd_info *mtd);
120 
121 /* Read NFC register */
122 static inline u16 nfc_read(struct mtd_info *mtd, uint reg)
123 {
124 	struct nand_chip *chip = mtd_to_nand(mtd);
125 	struct mpc5121_nfc_prv *prv = nand_get_controller_data(chip);
126 
127 	return in_be16(prv->regs + reg);
128 }
129 
130 /* Write NFC register */
131 static inline void nfc_write(struct mtd_info *mtd, uint reg, u16 val)
132 {
133 	struct nand_chip *chip = mtd_to_nand(mtd);
134 	struct mpc5121_nfc_prv *prv = nand_get_controller_data(chip);
135 
136 	out_be16(prv->regs + reg, val);
137 }
138 
139 /* Set bits in NFC register */
140 static inline void nfc_set(struct mtd_info *mtd, uint reg, u16 bits)
141 {
142 	nfc_write(mtd, reg, nfc_read(mtd, reg) | bits);
143 }
144 
145 /* Clear bits in NFC register */
146 static inline void nfc_clear(struct mtd_info *mtd, uint reg, u16 bits)
147 {
148 	nfc_write(mtd, reg, nfc_read(mtd, reg) & ~bits);
149 }
150 
151 /* Invoke address cycle */
152 static inline void mpc5121_nfc_send_addr(struct mtd_info *mtd, u16 addr)
153 {
154 	nfc_write(mtd, NFC_FLASH_ADDR, addr);
155 	nfc_write(mtd, NFC_CONFIG2, NFC_ADDRESS);
156 	mpc5121_nfc_done(mtd);
157 }
158 
159 /* Invoke command cycle */
160 static inline void mpc5121_nfc_send_cmd(struct mtd_info *mtd, u16 cmd)
161 {
162 	nfc_write(mtd, NFC_FLASH_CMD, cmd);
163 	nfc_write(mtd, NFC_CONFIG2, NFC_COMMAND);
164 	mpc5121_nfc_done(mtd);
165 }
166 
167 /* Send data from NFC buffers to NAND flash */
168 static inline void mpc5121_nfc_send_prog_page(struct mtd_info *mtd)
169 {
170 	nfc_clear(mtd, NFC_BUF_ADDR, NFC_RBA_MASK);
171 	nfc_write(mtd, NFC_CONFIG2, NFC_INPUT);
172 	mpc5121_nfc_done(mtd);
173 }
174 
175 /* Receive data from NAND flash */
176 static inline void mpc5121_nfc_send_read_page(struct mtd_info *mtd)
177 {
178 	nfc_clear(mtd, NFC_BUF_ADDR, NFC_RBA_MASK);
179 	nfc_write(mtd, NFC_CONFIG2, NFC_OUTPUT);
180 	mpc5121_nfc_done(mtd);
181 }
182 
183 /* Receive ID from NAND flash */
184 static inline void mpc5121_nfc_send_read_id(struct mtd_info *mtd)
185 {
186 	nfc_clear(mtd, NFC_BUF_ADDR, NFC_RBA_MASK);
187 	nfc_write(mtd, NFC_CONFIG2, NFC_ID);
188 	mpc5121_nfc_done(mtd);
189 }
190 
191 /* Receive status from NAND flash */
192 static inline void mpc5121_nfc_send_read_status(struct mtd_info *mtd)
193 {
194 	nfc_clear(mtd, NFC_BUF_ADDR, NFC_RBA_MASK);
195 	nfc_write(mtd, NFC_CONFIG2, NFC_STATUS);
196 	mpc5121_nfc_done(mtd);
197 }
198 
199 /* NFC interrupt handler */
200 static irqreturn_t mpc5121_nfc_irq(int irq, void *data)
201 {
202 	struct mtd_info *mtd = data;
203 	struct nand_chip *chip = mtd_to_nand(mtd);
204 	struct mpc5121_nfc_prv *prv = nand_get_controller_data(chip);
205 
206 	nfc_set(mtd, NFC_CONFIG1, NFC_INT_MASK);
207 	wake_up(&prv->irq_waitq);
208 
209 	return IRQ_HANDLED;
210 }
211 
212 /* Wait for operation complete */
213 static void mpc5121_nfc_done(struct mtd_info *mtd)
214 {
215 	struct nand_chip *chip = mtd_to_nand(mtd);
216 	struct mpc5121_nfc_prv *prv = nand_get_controller_data(chip);
217 	int rv;
218 
219 	if ((nfc_read(mtd, NFC_CONFIG2) & NFC_INT) == 0) {
220 		nfc_clear(mtd, NFC_CONFIG1, NFC_INT_MASK);
221 		rv = wait_event_timeout(prv->irq_waitq,
222 			(nfc_read(mtd, NFC_CONFIG2) & NFC_INT), NFC_TIMEOUT);
223 
224 		if (!rv)
225 			dev_warn(prv->dev,
226 				"Timeout while waiting for interrupt.\n");
227 	}
228 
229 	nfc_clear(mtd, NFC_CONFIG2, NFC_INT);
230 }
231 
232 /* Do address cycle(s) */
233 static void mpc5121_nfc_addr_cycle(struct mtd_info *mtd, int column, int page)
234 {
235 	struct nand_chip *chip = mtd_to_nand(mtd);
236 	u32 pagemask = chip->pagemask;
237 
238 	if (column != -1) {
239 		mpc5121_nfc_send_addr(mtd, column);
240 		if (mtd->writesize > 512)
241 			mpc5121_nfc_send_addr(mtd, column >> 8);
242 	}
243 
244 	if (page != -1) {
245 		do {
246 			mpc5121_nfc_send_addr(mtd, page & 0xFF);
247 			page >>= 8;
248 			pagemask >>= 8;
249 		} while (pagemask);
250 	}
251 }
252 
253 /* Control chip select signals */
254 static void mpc5121_nfc_select_chip(struct nand_chip *nand, int chip)
255 {
256 	struct mtd_info *mtd = nand_to_mtd(nand);
257 
258 	if (chip < 0) {
259 		nfc_clear(mtd, NFC_CONFIG1, NFC_CE);
260 		return;
261 	}
262 
263 	nfc_clear(mtd, NFC_BUF_ADDR, NFC_ACTIVE_CS_MASK);
264 	nfc_set(mtd, NFC_BUF_ADDR, (chip << NFC_ACTIVE_CS_SHIFT) &
265 							NFC_ACTIVE_CS_MASK);
266 	nfc_set(mtd, NFC_CONFIG1, NFC_CE);
267 }
268 
269 /* Init external chip select logic on ADS5121 board */
270 static int ads5121_chipselect_init(struct mtd_info *mtd)
271 {
272 	struct nand_chip *chip = mtd_to_nand(mtd);
273 	struct mpc5121_nfc_prv *prv = nand_get_controller_data(chip);
274 	struct device_node *dn;
275 
276 	dn = of_find_compatible_node(NULL, NULL, "fsl,mpc5121ads-cpld");
277 	if (dn) {
278 		prv->csreg = of_iomap(dn, 0);
279 		of_node_put(dn);
280 		if (!prv->csreg)
281 			return -ENOMEM;
282 
283 		/* CPLD Register 9 controls NAND /CE Lines */
284 		prv->csreg += 9;
285 		return 0;
286 	}
287 
288 	return -EINVAL;
289 }
290 
291 /* Control chips select signal on ADS5121 board */
292 static void ads5121_select_chip(struct nand_chip *nand, int chip)
293 {
294 	struct mtd_info *mtd = nand_to_mtd(nand);
295 	struct mpc5121_nfc_prv *prv = nand_get_controller_data(nand);
296 	u8 v;
297 
298 	v = in_8(prv->csreg);
299 	v |= 0x0F;
300 
301 	if (chip >= 0) {
302 		mpc5121_nfc_select_chip(nand, 0);
303 		v &= ~(1 << chip);
304 	} else
305 		mpc5121_nfc_select_chip(nand, -1);
306 
307 	out_8(prv->csreg, v);
308 }
309 
310 /* Read NAND Ready/Busy signal */
311 static int mpc5121_nfc_dev_ready(struct nand_chip *nand)
312 {
313 	/*
314 	 * NFC handles ready/busy signal internally. Therefore, this function
315 	 * always returns status as ready.
316 	 */
317 	return 1;
318 }
319 
320 /* Write command to NAND flash */
321 static void mpc5121_nfc_command(struct nand_chip *chip, unsigned command,
322 				int column, int page)
323 {
324 	struct mtd_info *mtd = nand_to_mtd(chip);
325 	struct mpc5121_nfc_prv *prv = nand_get_controller_data(chip);
326 
327 	prv->column = (column >= 0) ? column : 0;
328 	prv->spareonly = 0;
329 
330 	switch (command) {
331 	case NAND_CMD_PAGEPROG:
332 		mpc5121_nfc_send_prog_page(mtd);
333 		break;
334 	/*
335 	 * NFC does not support sub-page reads and writes,
336 	 * so emulate them using full page transfers.
337 	 */
338 	case NAND_CMD_READ0:
339 		column = 0;
340 		break;
341 
342 	case NAND_CMD_READ1:
343 		prv->column += 256;
344 		command = NAND_CMD_READ0;
345 		column = 0;
346 		break;
347 
348 	case NAND_CMD_READOOB:
349 		prv->spareonly = 1;
350 		command = NAND_CMD_READ0;
351 		column = 0;
352 		break;
353 
354 	case NAND_CMD_SEQIN:
355 		mpc5121_nfc_command(chip, NAND_CMD_READ0, column, page);
356 		column = 0;
357 		break;
358 
359 	case NAND_CMD_ERASE1:
360 	case NAND_CMD_ERASE2:
361 	case NAND_CMD_READID:
362 	case NAND_CMD_STATUS:
363 		break;
364 
365 	default:
366 		return;
367 	}
368 
369 	mpc5121_nfc_send_cmd(mtd, command);
370 	mpc5121_nfc_addr_cycle(mtd, column, page);
371 
372 	switch (command) {
373 	case NAND_CMD_READ0:
374 		if (mtd->writesize > 512)
375 			mpc5121_nfc_send_cmd(mtd, NAND_CMD_READSTART);
376 		mpc5121_nfc_send_read_page(mtd);
377 		break;
378 
379 	case NAND_CMD_READID:
380 		mpc5121_nfc_send_read_id(mtd);
381 		break;
382 
383 	case NAND_CMD_STATUS:
384 		mpc5121_nfc_send_read_status(mtd);
385 		if (chip->options & NAND_BUSWIDTH_16)
386 			prv->column = 1;
387 		else
388 			prv->column = 0;
389 		break;
390 	}
391 }
392 
393 /* Copy data from/to NFC spare buffers. */
394 static void mpc5121_nfc_copy_spare(struct mtd_info *mtd, uint offset,
395 						u8 *buffer, uint size, int wr)
396 {
397 	struct nand_chip *nand = mtd_to_nand(mtd);
398 	struct mpc5121_nfc_prv *prv = nand_get_controller_data(nand);
399 	uint o, s, sbsize, blksize;
400 
401 	/*
402 	 * NAND spare area is available through NFC spare buffers.
403 	 * The NFC divides spare area into (page_size / 512) chunks.
404 	 * Each chunk is placed into separate spare memory area, using
405 	 * first (spare_size / num_of_chunks) bytes of the buffer.
406 	 *
407 	 * For NAND device in which the spare area is not divided fully
408 	 * by the number of chunks, number of used bytes in each spare
409 	 * buffer is rounded down to the nearest even number of bytes,
410 	 * and all remaining bytes are added to the last used spare area.
411 	 *
412 	 * For more information read section 26.6.10 of MPC5121e
413 	 * Microcontroller Reference Manual, Rev. 3.
414 	 */
415 
416 	/* Calculate number of valid bytes in each spare buffer */
417 	sbsize = (mtd->oobsize / (mtd->writesize / 512)) & ~1;
418 
419 	while (size) {
420 		/* Calculate spare buffer number */
421 		s = offset / sbsize;
422 		if (s > NFC_SPARE_BUFFERS - 1)
423 			s = NFC_SPARE_BUFFERS - 1;
424 
425 		/*
426 		 * Calculate offset to requested data block in selected spare
427 		 * buffer and its size.
428 		 */
429 		o = offset - (s * sbsize);
430 		blksize = min(sbsize - o, size);
431 
432 		if (wr)
433 			memcpy_toio(prv->regs + NFC_SPARE_AREA(s) + o,
434 							buffer, blksize);
435 		else
436 			memcpy_fromio(buffer,
437 				prv->regs + NFC_SPARE_AREA(s) + o, blksize);
438 
439 		buffer += blksize;
440 		offset += blksize;
441 		size -= blksize;
442 	}
443 }
444 
445 /* Copy data from/to NFC main and spare buffers */
446 static void mpc5121_nfc_buf_copy(struct mtd_info *mtd, u_char *buf, int len,
447 									int wr)
448 {
449 	struct nand_chip *chip = mtd_to_nand(mtd);
450 	struct mpc5121_nfc_prv *prv = nand_get_controller_data(chip);
451 	uint c = prv->column;
452 	uint l;
453 
454 	/* Handle spare area access */
455 	if (prv->spareonly || c >= mtd->writesize) {
456 		/* Calculate offset from beginning of spare area */
457 		if (c >= mtd->writesize)
458 			c -= mtd->writesize;
459 
460 		prv->column += len;
461 		mpc5121_nfc_copy_spare(mtd, c, buf, len, wr);
462 		return;
463 	}
464 
465 	/*
466 	 * Handle main area access - limit copy length to prevent
467 	 * crossing main/spare boundary.
468 	 */
469 	l = min((uint)len, mtd->writesize - c);
470 	prv->column += l;
471 
472 	if (wr)
473 		memcpy_toio(prv->regs + NFC_MAIN_AREA(0) + c, buf, l);
474 	else
475 		memcpy_fromio(buf, prv->regs + NFC_MAIN_AREA(0) + c, l);
476 
477 	/* Handle crossing main/spare boundary */
478 	if (l != len) {
479 		buf += l;
480 		len -= l;
481 		mpc5121_nfc_buf_copy(mtd, buf, len, wr);
482 	}
483 }
484 
485 /* Read data from NFC buffers */
486 static void mpc5121_nfc_read_buf(struct nand_chip *chip, u_char *buf, int len)
487 {
488 	mpc5121_nfc_buf_copy(nand_to_mtd(chip), buf, len, 0);
489 }
490 
491 /* Write data to NFC buffers */
492 static void mpc5121_nfc_write_buf(struct nand_chip *chip, const u_char *buf,
493 				  int len)
494 {
495 	mpc5121_nfc_buf_copy(nand_to_mtd(chip), (u_char *)buf, len, 1);
496 }
497 
498 /* Read byte from NFC buffers */
499 static u8 mpc5121_nfc_read_byte(struct nand_chip *chip)
500 {
501 	u8 tmp;
502 
503 	mpc5121_nfc_read_buf(chip, &tmp, sizeof(tmp));
504 
505 	return tmp;
506 }
507 
508 /*
509  * Read NFC configuration from Reset Config Word
510  *
511  * NFC is configured during reset in basis of information stored
512  * in Reset Config Word. There is no other way to set NAND block
513  * size, spare size and bus width.
514  */
515 static int mpc5121_nfc_read_hw_config(struct mtd_info *mtd)
516 {
517 	struct nand_chip *chip = mtd_to_nand(mtd);
518 	struct mpc5121_nfc_prv *prv = nand_get_controller_data(chip);
519 	struct mpc512x_reset_module *rm;
520 	struct device_node *rmnode;
521 	uint rcw_pagesize = 0;
522 	uint rcw_sparesize = 0;
523 	uint rcw_width;
524 	uint rcwh;
525 	uint romloc, ps;
526 	int ret = 0;
527 
528 	rmnode = of_find_compatible_node(NULL, NULL, "fsl,mpc5121-reset");
529 	if (!rmnode) {
530 		dev_err(prv->dev, "Missing 'fsl,mpc5121-reset' "
531 					"node in device tree!\n");
532 		return -ENODEV;
533 	}
534 
535 	rm = of_iomap(rmnode, 0);
536 	if (!rm) {
537 		dev_err(prv->dev, "Error mapping reset module node!\n");
538 		ret = -EBUSY;
539 		goto out;
540 	}
541 
542 	rcwh = in_be32(&rm->rcwhr);
543 
544 	/* Bit 6: NFC bus width */
545 	rcw_width = ((rcwh >> 6) & 0x1) ? 2 : 1;
546 
547 	/* Bit 7: NFC Page/Spare size */
548 	ps = (rcwh >> 7) & 0x1;
549 
550 	/* Bits [22:21]: ROM Location */
551 	romloc = (rcwh >> 21) & 0x3;
552 
553 	/* Decode RCW bits */
554 	switch ((ps << 2) | romloc) {
555 	case 0x00:
556 	case 0x01:
557 		rcw_pagesize = 512;
558 		rcw_sparesize = 16;
559 		break;
560 	case 0x02:
561 	case 0x03:
562 		rcw_pagesize = 4096;
563 		rcw_sparesize = 128;
564 		break;
565 	case 0x04:
566 	case 0x05:
567 		rcw_pagesize = 2048;
568 		rcw_sparesize = 64;
569 		break;
570 	case 0x06:
571 	case 0x07:
572 		rcw_pagesize = 4096;
573 		rcw_sparesize = 218;
574 		break;
575 	}
576 
577 	mtd->writesize = rcw_pagesize;
578 	mtd->oobsize = rcw_sparesize;
579 	if (rcw_width == 2)
580 		chip->options |= NAND_BUSWIDTH_16;
581 
582 	dev_notice(prv->dev, "Configured for "
583 				"%u-bit NAND, page size %u "
584 				"with %u spare.\n",
585 				rcw_width * 8, rcw_pagesize,
586 				rcw_sparesize);
587 	iounmap(rm);
588 out:
589 	of_node_put(rmnode);
590 	return ret;
591 }
592 
593 /* Free driver resources */
594 static void mpc5121_nfc_free(struct device *dev, struct mtd_info *mtd)
595 {
596 	struct nand_chip *chip = mtd_to_nand(mtd);
597 	struct mpc5121_nfc_prv *prv = nand_get_controller_data(chip);
598 
599 	if (prv->clk)
600 		clk_disable_unprepare(prv->clk);
601 
602 	if (prv->csreg)
603 		iounmap(prv->csreg);
604 }
605 
606 static int mpc5121_nfc_attach_chip(struct nand_chip *chip)
607 {
608 	chip->ecc.engine_type = NAND_ECC_ENGINE_TYPE_SOFT;
609 
610 	if (chip->ecc.algo == NAND_ECC_ALGO_UNKNOWN)
611 		chip->ecc.algo = NAND_ECC_ALGO_HAMMING;
612 
613 	return 0;
614 }
615 
616 static const struct nand_controller_ops mpc5121_nfc_ops = {
617 	.attach_chip = mpc5121_nfc_attach_chip,
618 };
619 
620 static int mpc5121_nfc_probe(struct platform_device *op)
621 {
622 	struct device_node *dn = op->dev.of_node;
623 	struct clk *clk;
624 	struct device *dev = &op->dev;
625 	struct mpc5121_nfc_prv *prv;
626 	struct resource res;
627 	struct mtd_info *mtd;
628 	struct nand_chip *chip;
629 	unsigned long regs_paddr, regs_size;
630 	const __be32 *chips_no;
631 	int resettime = 0;
632 	int retval = 0;
633 	int rev, len;
634 
635 	/*
636 	 * Check SoC revision. This driver supports only NFC
637 	 * in MPC5121 revision 2 and MPC5123 revision 3.
638 	 */
639 	rev = (mfspr(SPRN_SVR) >> 4) & 0xF;
640 	if ((rev != 2) && (rev != 3)) {
641 		dev_err(dev, "SoC revision %u is not supported!\n", rev);
642 		return -ENXIO;
643 	}
644 
645 	prv = devm_kzalloc(dev, sizeof(*prv), GFP_KERNEL);
646 	if (!prv)
647 		return -ENOMEM;
648 
649 	chip = &prv->chip;
650 	mtd = nand_to_mtd(chip);
651 
652 	nand_controller_init(&prv->controller);
653 	prv->controller.ops = &mpc5121_nfc_ops;
654 	chip->controller = &prv->controller;
655 
656 	mtd->dev.parent = dev;
657 	nand_set_controller_data(chip, prv);
658 	nand_set_flash_node(chip, dn);
659 	prv->dev = dev;
660 
661 	/* Read NFC configuration from Reset Config Word */
662 	retval = mpc5121_nfc_read_hw_config(mtd);
663 	if (retval) {
664 		dev_err(dev, "Unable to read NFC config!\n");
665 		return retval;
666 	}
667 
668 	prv->irq = irq_of_parse_and_map(dn, 0);
669 	if (prv->irq == NO_IRQ) {
670 		dev_err(dev, "Error mapping IRQ!\n");
671 		return -EINVAL;
672 	}
673 
674 	retval = of_address_to_resource(dn, 0, &res);
675 	if (retval) {
676 		dev_err(dev, "Error parsing memory region!\n");
677 		return retval;
678 	}
679 
680 	chips_no = of_get_property(dn, "chips", &len);
681 	if (!chips_no || len != sizeof(*chips_no)) {
682 		dev_err(dev, "Invalid/missing 'chips' property!\n");
683 		return -EINVAL;
684 	}
685 
686 	regs_paddr = res.start;
687 	regs_size = resource_size(&res);
688 
689 	if (!devm_request_mem_region(dev, regs_paddr, regs_size, DRV_NAME)) {
690 		dev_err(dev, "Error requesting memory region!\n");
691 		return -EBUSY;
692 	}
693 
694 	prv->regs = devm_ioremap(dev, regs_paddr, regs_size);
695 	if (!prv->regs) {
696 		dev_err(dev, "Error mapping memory region!\n");
697 		return -ENOMEM;
698 	}
699 
700 	mtd->name = "MPC5121 NAND";
701 	chip->legacy.dev_ready = mpc5121_nfc_dev_ready;
702 	chip->legacy.cmdfunc = mpc5121_nfc_command;
703 	chip->legacy.read_byte = mpc5121_nfc_read_byte;
704 	chip->legacy.read_buf = mpc5121_nfc_read_buf;
705 	chip->legacy.write_buf = mpc5121_nfc_write_buf;
706 	chip->legacy.select_chip = mpc5121_nfc_select_chip;
707 	chip->legacy.set_features = nand_get_set_features_notsupp;
708 	chip->legacy.get_features = nand_get_set_features_notsupp;
709 	chip->bbt_options = NAND_BBT_USE_FLASH;
710 
711 	/* Support external chip-select logic on ADS5121 board */
712 	if (of_machine_is_compatible("fsl,mpc5121ads")) {
713 		retval = ads5121_chipselect_init(mtd);
714 		if (retval) {
715 			dev_err(dev, "Chipselect init error!\n");
716 			return retval;
717 		}
718 
719 		chip->legacy.select_chip = ads5121_select_chip;
720 	}
721 
722 	/* Enable NFC clock */
723 	clk = devm_clk_get(dev, "ipg");
724 	if (IS_ERR(clk)) {
725 		dev_err(dev, "Unable to acquire NFC clock!\n");
726 		retval = PTR_ERR(clk);
727 		goto error;
728 	}
729 	retval = clk_prepare_enable(clk);
730 	if (retval) {
731 		dev_err(dev, "Unable to enable NFC clock!\n");
732 		goto error;
733 	}
734 	prv->clk = clk;
735 
736 	/* Reset NAND Flash controller */
737 	nfc_set(mtd, NFC_CONFIG1, NFC_RESET);
738 	while (nfc_read(mtd, NFC_CONFIG1) & NFC_RESET) {
739 		if (resettime++ >= NFC_RESET_TIMEOUT) {
740 			dev_err(dev, "Timeout while resetting NFC!\n");
741 			retval = -EINVAL;
742 			goto error;
743 		}
744 
745 		udelay(1);
746 	}
747 
748 	/* Enable write to NFC memory */
749 	nfc_write(mtd, NFC_CONFIG, NFC_BLS_UNLOCKED);
750 
751 	/* Enable write to all NAND pages */
752 	nfc_write(mtd, NFC_UNLOCKSTART_BLK0, 0x0000);
753 	nfc_write(mtd, NFC_UNLOCKEND_BLK0, 0xFFFF);
754 	nfc_write(mtd, NFC_WRPROT, NFC_WPC_UNLOCK);
755 
756 	/*
757 	 * Setup NFC:
758 	 *	- Big Endian transfers,
759 	 *	- Interrupt after full page read/write.
760 	 */
761 	nfc_write(mtd, NFC_CONFIG1, NFC_BIG_ENDIAN | NFC_INT_MASK |
762 							NFC_FULL_PAGE_INT);
763 
764 	/* Set spare area size */
765 	nfc_write(mtd, NFC_SPAS, mtd->oobsize >> 1);
766 
767 	init_waitqueue_head(&prv->irq_waitq);
768 	retval = devm_request_irq(dev, prv->irq, &mpc5121_nfc_irq, 0, DRV_NAME,
769 									mtd);
770 	if (retval) {
771 		dev_err(dev, "Error requesting IRQ!\n");
772 		goto error;
773 	}
774 
775 	/* Detect NAND chips */
776 	retval = nand_scan(chip, be32_to_cpup(chips_no));
777 	if (retval) {
778 		dev_err(dev, "NAND Flash not found !\n");
779 		goto error;
780 	}
781 
782 	/* Set erase block size */
783 	switch (mtd->erasesize / mtd->writesize) {
784 	case 32:
785 		nfc_set(mtd, NFC_CONFIG1, NFC_PPB_32);
786 		break;
787 
788 	case 64:
789 		nfc_set(mtd, NFC_CONFIG1, NFC_PPB_64);
790 		break;
791 
792 	case 128:
793 		nfc_set(mtd, NFC_CONFIG1, NFC_PPB_128);
794 		break;
795 
796 	case 256:
797 		nfc_set(mtd, NFC_CONFIG1, NFC_PPB_256);
798 		break;
799 
800 	default:
801 		dev_err(dev, "Unsupported NAND flash!\n");
802 		retval = -ENXIO;
803 		goto error;
804 	}
805 
806 	dev_set_drvdata(dev, mtd);
807 
808 	/* Register device in MTD */
809 	retval = mtd_device_register(mtd, NULL, 0);
810 	if (retval) {
811 		dev_err(dev, "Error adding MTD device!\n");
812 		goto error;
813 	}
814 
815 	return 0;
816 error:
817 	mpc5121_nfc_free(dev, mtd);
818 	return retval;
819 }
820 
821 static int mpc5121_nfc_remove(struct platform_device *op)
822 {
823 	struct device *dev = &op->dev;
824 	struct mtd_info *mtd = dev_get_drvdata(dev);
825 	int ret;
826 
827 	ret = mtd_device_unregister(mtd);
828 	WARN_ON(ret);
829 	nand_cleanup(mtd_to_nand(mtd));
830 	mpc5121_nfc_free(dev, mtd);
831 
832 	return 0;
833 }
834 
835 static const struct of_device_id mpc5121_nfc_match[] = {
836 	{ .compatible = "fsl,mpc5121-nfc", },
837 	{},
838 };
839 MODULE_DEVICE_TABLE(of, mpc5121_nfc_match);
840 
841 static struct platform_driver mpc5121_nfc_driver = {
842 	.probe		= mpc5121_nfc_probe,
843 	.remove		= mpc5121_nfc_remove,
844 	.driver		= {
845 		.name = DRV_NAME,
846 		.of_match_table = mpc5121_nfc_match,
847 	},
848 };
849 
850 module_platform_driver(mpc5121_nfc_driver);
851 
852 MODULE_AUTHOR("Freescale Semiconductor, Inc.");
853 MODULE_DESCRIPTION("MPC5121 NAND MTD driver");
854 MODULE_LICENSE("GPL");
855