xref: /linux/drivers/mtd/nand/raw/mpc5121_nfc.c (revision 9cebfe6504488198b012e746bc6b313f88b95439)
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.h>
25 #include <linux/of_address.h>
26 #include <linux/platform_device.h>
27 
28 #include <asm/mpc5121.h>
29 
30 /* Addresses for NFC MAIN RAM BUFFER areas */
31 #define NFC_MAIN_AREA(n)	((n) *  0x200)
32 
33 /* Addresses for NFC SPARE BUFFER areas */
34 #define NFC_SPARE_BUFFERS	8
35 #define NFC_SPARE_LEN		0x40
36 #define NFC_SPARE_AREA(n)	(0x1000 + ((n) * NFC_SPARE_LEN))
37 
38 /* MPC5121 NFC registers */
39 #define NFC_BUF_ADDR		0x1E04
40 #define NFC_FLASH_ADDR		0x1E06
41 #define NFC_FLASH_CMD		0x1E08
42 #define NFC_CONFIG		0x1E0A
43 #define NFC_ECC_STATUS1		0x1E0C
44 #define NFC_ECC_STATUS2		0x1E0E
45 #define NFC_SPAS		0x1E10
46 #define NFC_WRPROT		0x1E12
47 #define NFC_NF_WRPRST		0x1E18
48 #define NFC_CONFIG1		0x1E1A
49 #define NFC_CONFIG2		0x1E1C
50 #define NFC_UNLOCKSTART_BLK0	0x1E20
51 #define NFC_UNLOCKEND_BLK0	0x1E22
52 #define NFC_UNLOCKSTART_BLK1	0x1E24
53 #define NFC_UNLOCKEND_BLK1	0x1E26
54 #define NFC_UNLOCKSTART_BLK2	0x1E28
55 #define NFC_UNLOCKEND_BLK2	0x1E2A
56 #define NFC_UNLOCKSTART_BLK3	0x1E2C
57 #define NFC_UNLOCKEND_BLK3	0x1E2E
58 
59 /* Bit Definitions: NFC_BUF_ADDR */
60 #define NFC_RBA_MASK		(7 << 0)
61 #define NFC_ACTIVE_CS_SHIFT	5
62 #define NFC_ACTIVE_CS_MASK	(3 << NFC_ACTIVE_CS_SHIFT)
63 
64 /* Bit Definitions: NFC_CONFIG */
65 #define NFC_BLS_UNLOCKED	(1 << 1)
66 
67 /* Bit Definitions: NFC_CONFIG1 */
68 #define NFC_ECC_4BIT		(1 << 0)
69 #define NFC_FULL_PAGE_DMA	(1 << 1)
70 #define NFC_SPARE_ONLY		(1 << 2)
71 #define NFC_ECC_ENABLE		(1 << 3)
72 #define NFC_INT_MASK		(1 << 4)
73 #define NFC_BIG_ENDIAN		(1 << 5)
74 #define NFC_RESET		(1 << 6)
75 #define NFC_CE			(1 << 7)
76 #define NFC_ONE_CYCLE		(1 << 8)
77 #define NFC_PPB_32		(0 << 9)
78 #define NFC_PPB_64		(1 << 9)
79 #define NFC_PPB_128		(2 << 9)
80 #define NFC_PPB_256		(3 << 9)
81 #define NFC_PPB_MASK		(3 << 9)
82 #define NFC_FULL_PAGE_INT	(1 << 11)
83 
84 /* Bit Definitions: NFC_CONFIG2 */
85 #define NFC_COMMAND		(1 << 0)
86 #define NFC_ADDRESS		(1 << 1)
87 #define NFC_INPUT		(1 << 2)
88 #define NFC_OUTPUT		(1 << 3)
89 #define NFC_ID			(1 << 4)
90 #define NFC_STATUS		(1 << 5)
91 #define NFC_CMD_FAIL		(1 << 15)
92 #define NFC_INT			(1 << 15)
93 
94 /* Bit Definitions: NFC_WRPROT */
95 #define NFC_WPC_LOCK_TIGHT	(1 << 0)
96 #define NFC_WPC_LOCK		(1 << 1)
97 #define NFC_WPC_UNLOCK		(1 << 2)
98 
99 #define	DRV_NAME		"mpc5121_nfc"
100 
101 /* Timeouts */
102 #define NFC_RESET_TIMEOUT	1000		/* 1 ms */
103 #define NFC_TIMEOUT		(HZ / 10)	/* 1/10 s */
104 
105 struct mpc5121_nfc_prv {
106 	struct nand_controller	controller;
107 	struct nand_chip	chip;
108 	int			irq;
109 	void __iomem		*regs;
110 	struct clk		*clk;
111 	wait_queue_head_t	irq_waitq;
112 	uint			column;
113 	int			spareonly;
114 	void __iomem		*csreg;
115 	struct device		*dev;
116 };
117 
118 static void mpc5121_nfc_done(struct mtd_info *mtd);
119 
120 /* Read NFC register */
121 static inline u16 nfc_read(struct mtd_info *mtd, uint reg)
122 {
123 	struct nand_chip *chip = mtd_to_nand(mtd);
124 	struct mpc5121_nfc_prv *prv = nand_get_controller_data(chip);
125 
126 	return in_be16(prv->regs + reg);
127 }
128 
129 /* Write NFC register */
130 static inline void nfc_write(struct mtd_info *mtd, uint reg, u16 val)
131 {
132 	struct nand_chip *chip = mtd_to_nand(mtd);
133 	struct mpc5121_nfc_prv *prv = nand_get_controller_data(chip);
134 
135 	out_be16(prv->regs + reg, val);
136 }
137 
138 /* Set bits in NFC register */
139 static inline void nfc_set(struct mtd_info *mtd, uint reg, u16 bits)
140 {
141 	nfc_write(mtd, reg, nfc_read(mtd, reg) | bits);
142 }
143 
144 /* Clear bits in NFC register */
145 static inline void nfc_clear(struct mtd_info *mtd, uint reg, u16 bits)
146 {
147 	nfc_write(mtd, reg, nfc_read(mtd, reg) & ~bits);
148 }
149 
150 /* Invoke address cycle */
151 static inline void mpc5121_nfc_send_addr(struct mtd_info *mtd, u16 addr)
152 {
153 	nfc_write(mtd, NFC_FLASH_ADDR, addr);
154 	nfc_write(mtd, NFC_CONFIG2, NFC_ADDRESS);
155 	mpc5121_nfc_done(mtd);
156 }
157 
158 /* Invoke command cycle */
159 static inline void mpc5121_nfc_send_cmd(struct mtd_info *mtd, u16 cmd)
160 {
161 	nfc_write(mtd, NFC_FLASH_CMD, cmd);
162 	nfc_write(mtd, NFC_CONFIG2, NFC_COMMAND);
163 	mpc5121_nfc_done(mtd);
164 }
165 
166 /* Send data from NFC buffers to NAND flash */
167 static inline void mpc5121_nfc_send_prog_page(struct mtd_info *mtd)
168 {
169 	nfc_clear(mtd, NFC_BUF_ADDR, NFC_RBA_MASK);
170 	nfc_write(mtd, NFC_CONFIG2, NFC_INPUT);
171 	mpc5121_nfc_done(mtd);
172 }
173 
174 /* Receive data from NAND flash */
175 static inline void mpc5121_nfc_send_read_page(struct mtd_info *mtd)
176 {
177 	nfc_clear(mtd, NFC_BUF_ADDR, NFC_RBA_MASK);
178 	nfc_write(mtd, NFC_CONFIG2, NFC_OUTPUT);
179 	mpc5121_nfc_done(mtd);
180 }
181 
182 /* Receive ID from NAND flash */
183 static inline void mpc5121_nfc_send_read_id(struct mtd_info *mtd)
184 {
185 	nfc_clear(mtd, NFC_BUF_ADDR, NFC_RBA_MASK);
186 	nfc_write(mtd, NFC_CONFIG2, NFC_ID);
187 	mpc5121_nfc_done(mtd);
188 }
189 
190 /* Receive status from NAND flash */
191 static inline void mpc5121_nfc_send_read_status(struct mtd_info *mtd)
192 {
193 	nfc_clear(mtd, NFC_BUF_ADDR, NFC_RBA_MASK);
194 	nfc_write(mtd, NFC_CONFIG2, NFC_STATUS);
195 	mpc5121_nfc_done(mtd);
196 }
197 
198 /* NFC interrupt handler */
199 static irqreturn_t mpc5121_nfc_irq(int irq, void *data)
200 {
201 	struct mtd_info *mtd = data;
202 	struct nand_chip *chip = mtd_to_nand(mtd);
203 	struct mpc5121_nfc_prv *prv = nand_get_controller_data(chip);
204 
205 	nfc_set(mtd, NFC_CONFIG1, NFC_INT_MASK);
206 	wake_up(&prv->irq_waitq);
207 
208 	return IRQ_HANDLED;
209 }
210 
211 /* Wait for operation complete */
212 static void mpc5121_nfc_done(struct mtd_info *mtd)
213 {
214 	struct nand_chip *chip = mtd_to_nand(mtd);
215 	struct mpc5121_nfc_prv *prv = nand_get_controller_data(chip);
216 	int rv;
217 
218 	if ((nfc_read(mtd, NFC_CONFIG2) & NFC_INT) == 0) {
219 		nfc_clear(mtd, NFC_CONFIG1, NFC_INT_MASK);
220 		rv = wait_event_timeout(prv->irq_waitq,
221 			(nfc_read(mtd, NFC_CONFIG2) & NFC_INT), NFC_TIMEOUT);
222 
223 		if (!rv)
224 			dev_warn(prv->dev,
225 				"Timeout while waiting for interrupt.\n");
226 	}
227 
228 	nfc_clear(mtd, NFC_CONFIG2, NFC_INT);
229 }
230 
231 /* Do address cycle(s) */
232 static void mpc5121_nfc_addr_cycle(struct mtd_info *mtd, int column, int page)
233 {
234 	struct nand_chip *chip = mtd_to_nand(mtd);
235 	u32 pagemask = chip->pagemask;
236 
237 	if (column != -1) {
238 		mpc5121_nfc_send_addr(mtd, column);
239 		if (mtd->writesize > 512)
240 			mpc5121_nfc_send_addr(mtd, column >> 8);
241 	}
242 
243 	if (page != -1) {
244 		do {
245 			mpc5121_nfc_send_addr(mtd, page & 0xFF);
246 			page >>= 8;
247 			pagemask >>= 8;
248 		} while (pagemask);
249 	}
250 }
251 
252 /* Control chip select signals */
253 static void mpc5121_nfc_select_chip(struct nand_chip *nand, int chip)
254 {
255 	struct mtd_info *mtd = nand_to_mtd(nand);
256 
257 	if (chip < 0) {
258 		nfc_clear(mtd, NFC_CONFIG1, NFC_CE);
259 		return;
260 	}
261 
262 	nfc_clear(mtd, NFC_BUF_ADDR, NFC_ACTIVE_CS_MASK);
263 	nfc_set(mtd, NFC_BUF_ADDR, (chip << NFC_ACTIVE_CS_SHIFT) &
264 							NFC_ACTIVE_CS_MASK);
265 	nfc_set(mtd, NFC_CONFIG1, NFC_CE);
266 }
267 
268 /* Init external chip select logic on ADS5121 board */
269 static int ads5121_chipselect_init(struct mtd_info *mtd)
270 {
271 	struct nand_chip *chip = mtd_to_nand(mtd);
272 	struct mpc5121_nfc_prv *prv = nand_get_controller_data(chip);
273 	struct device_node *dn;
274 
275 	dn = of_find_compatible_node(NULL, NULL, "fsl,mpc5121ads-cpld");
276 	if (dn) {
277 		prv->csreg = of_iomap(dn, 0);
278 		of_node_put(dn);
279 		if (!prv->csreg)
280 			return -ENOMEM;
281 
282 		/* CPLD Register 9 controls NAND /CE Lines */
283 		prv->csreg += 9;
284 		return 0;
285 	}
286 
287 	return -EINVAL;
288 }
289 
290 /* Control chips select signal on ADS5121 board */
291 static void ads5121_select_chip(struct nand_chip *nand, int chip)
292 {
293 	struct mpc5121_nfc_prv *prv = nand_get_controller_data(nand);
294 	u8 v;
295 
296 	v = in_8(prv->csreg);
297 	v |= 0x0F;
298 
299 	if (chip >= 0) {
300 		mpc5121_nfc_select_chip(nand, 0);
301 		v &= ~(1 << chip);
302 	} else
303 		mpc5121_nfc_select_chip(nand, -1);
304 
305 	out_8(prv->csreg, v);
306 }
307 
308 /* Read NAND Ready/Busy signal */
309 static int mpc5121_nfc_dev_ready(struct nand_chip *nand)
310 {
311 	/*
312 	 * NFC handles ready/busy signal internally. Therefore, this function
313 	 * always returns status as ready.
314 	 */
315 	return 1;
316 }
317 
318 /* Write command to NAND flash */
319 static void mpc5121_nfc_command(struct nand_chip *chip, unsigned command,
320 				int column, int page)
321 {
322 	struct mtd_info *mtd = nand_to_mtd(chip);
323 	struct mpc5121_nfc_prv *prv = nand_get_controller_data(chip);
324 
325 	prv->column = (column >= 0) ? column : 0;
326 	prv->spareonly = 0;
327 
328 	switch (command) {
329 	case NAND_CMD_PAGEPROG:
330 		mpc5121_nfc_send_prog_page(mtd);
331 		break;
332 	/*
333 	 * NFC does not support sub-page reads and writes,
334 	 * so emulate them using full page transfers.
335 	 */
336 	case NAND_CMD_READ0:
337 		column = 0;
338 		break;
339 
340 	case NAND_CMD_READ1:
341 		prv->column += 256;
342 		command = NAND_CMD_READ0;
343 		column = 0;
344 		break;
345 
346 	case NAND_CMD_READOOB:
347 		prv->spareonly = 1;
348 		command = NAND_CMD_READ0;
349 		column = 0;
350 		break;
351 
352 	case NAND_CMD_SEQIN:
353 		mpc5121_nfc_command(chip, NAND_CMD_READ0, column, page);
354 		column = 0;
355 		break;
356 
357 	case NAND_CMD_ERASE1:
358 	case NAND_CMD_ERASE2:
359 	case NAND_CMD_READID:
360 	case NAND_CMD_STATUS:
361 		break;
362 
363 	default:
364 		return;
365 	}
366 
367 	mpc5121_nfc_send_cmd(mtd, command);
368 	mpc5121_nfc_addr_cycle(mtd, column, page);
369 
370 	switch (command) {
371 	case NAND_CMD_READ0:
372 		if (mtd->writesize > 512)
373 			mpc5121_nfc_send_cmd(mtd, NAND_CMD_READSTART);
374 		mpc5121_nfc_send_read_page(mtd);
375 		break;
376 
377 	case NAND_CMD_READID:
378 		mpc5121_nfc_send_read_id(mtd);
379 		break;
380 
381 	case NAND_CMD_STATUS:
382 		mpc5121_nfc_send_read_status(mtd);
383 		if (chip->options & NAND_BUSWIDTH_16)
384 			prv->column = 1;
385 		else
386 			prv->column = 0;
387 		break;
388 	}
389 }
390 
391 /* Copy data from/to NFC spare buffers. */
392 static void mpc5121_nfc_copy_spare(struct mtd_info *mtd, uint offset,
393 						u8 *buffer, uint size, int wr)
394 {
395 	struct nand_chip *nand = mtd_to_nand(mtd);
396 	struct mpc5121_nfc_prv *prv = nand_get_controller_data(nand);
397 	uint o, s, sbsize, blksize;
398 
399 	/*
400 	 * NAND spare area is available through NFC spare buffers.
401 	 * The NFC divides spare area into (page_size / 512) chunks.
402 	 * Each chunk is placed into separate spare memory area, using
403 	 * first (spare_size / num_of_chunks) bytes of the buffer.
404 	 *
405 	 * For NAND device in which the spare area is not divided fully
406 	 * by the number of chunks, number of used bytes in each spare
407 	 * buffer is rounded down to the nearest even number of bytes,
408 	 * and all remaining bytes are added to the last used spare area.
409 	 *
410 	 * For more information read section 26.6.10 of MPC5121e
411 	 * Microcontroller Reference Manual, Rev. 3.
412 	 */
413 
414 	/* Calculate number of valid bytes in each spare buffer */
415 	sbsize = (mtd->oobsize / (mtd->writesize / 512)) & ~1;
416 
417 	while (size) {
418 		/* Calculate spare buffer number */
419 		s = offset / sbsize;
420 		if (s > NFC_SPARE_BUFFERS - 1)
421 			s = NFC_SPARE_BUFFERS - 1;
422 
423 		/*
424 		 * Calculate offset to requested data block in selected spare
425 		 * buffer and its size.
426 		 */
427 		o = offset - (s * sbsize);
428 		blksize = min(sbsize - o, size);
429 
430 		if (wr)
431 			memcpy_toio(prv->regs + NFC_SPARE_AREA(s) + o,
432 							buffer, blksize);
433 		else
434 			memcpy_fromio(buffer,
435 				prv->regs + NFC_SPARE_AREA(s) + o, blksize);
436 
437 		buffer += blksize;
438 		offset += blksize;
439 		size -= blksize;
440 	}
441 }
442 
443 /* Copy data from/to NFC main and spare buffers */
444 static void mpc5121_nfc_buf_copy(struct mtd_info *mtd, u_char *buf, int len,
445 									int wr)
446 {
447 	struct nand_chip *chip = mtd_to_nand(mtd);
448 	struct mpc5121_nfc_prv *prv = nand_get_controller_data(chip);
449 	uint c = prv->column;
450 	uint l;
451 
452 	/* Handle spare area access */
453 	if (prv->spareonly || c >= mtd->writesize) {
454 		/* Calculate offset from beginning of spare area */
455 		if (c >= mtd->writesize)
456 			c -= mtd->writesize;
457 
458 		prv->column += len;
459 		mpc5121_nfc_copy_spare(mtd, c, buf, len, wr);
460 		return;
461 	}
462 
463 	/*
464 	 * Handle main area access - limit copy length to prevent
465 	 * crossing main/spare boundary.
466 	 */
467 	l = min((uint)len, mtd->writesize - c);
468 	prv->column += l;
469 
470 	if (wr)
471 		memcpy_toio(prv->regs + NFC_MAIN_AREA(0) + c, buf, l);
472 	else
473 		memcpy_fromio(buf, prv->regs + NFC_MAIN_AREA(0) + c, l);
474 
475 	/* Handle crossing main/spare boundary */
476 	if (l != len) {
477 		buf += l;
478 		len -= l;
479 		mpc5121_nfc_buf_copy(mtd, buf, len, wr);
480 	}
481 }
482 
483 /* Read data from NFC buffers */
484 static void mpc5121_nfc_read_buf(struct nand_chip *chip, u_char *buf, int len)
485 {
486 	mpc5121_nfc_buf_copy(nand_to_mtd(chip), buf, len, 0);
487 }
488 
489 /* Write data to NFC buffers */
490 static void mpc5121_nfc_write_buf(struct nand_chip *chip, const u_char *buf,
491 				  int len)
492 {
493 	mpc5121_nfc_buf_copy(nand_to_mtd(chip), (u_char *)buf, len, 1);
494 }
495 
496 /* Read byte from NFC buffers */
497 static u8 mpc5121_nfc_read_byte(struct nand_chip *chip)
498 {
499 	u8 tmp;
500 
501 	mpc5121_nfc_read_buf(chip, &tmp, sizeof(tmp));
502 
503 	return tmp;
504 }
505 
506 /*
507  * Read NFC configuration from Reset Config Word
508  *
509  * NFC is configured during reset in basis of information stored
510  * in Reset Config Word. There is no other way to set NAND block
511  * size, spare size and bus width.
512  */
513 static int mpc5121_nfc_read_hw_config(struct mtd_info *mtd)
514 {
515 	struct nand_chip *chip = mtd_to_nand(mtd);
516 	struct mpc5121_nfc_prv *prv = nand_get_controller_data(chip);
517 	struct mpc512x_reset_module *rm;
518 	struct device_node *rmnode;
519 	uint rcw_pagesize = 0;
520 	uint rcw_sparesize = 0;
521 	uint rcw_width;
522 	uint rcwh;
523 	uint romloc, ps;
524 	int ret = 0;
525 
526 	rmnode = of_find_compatible_node(NULL, NULL, "fsl,mpc5121-reset");
527 	if (!rmnode) {
528 		dev_err(prv->dev, "Missing 'fsl,mpc5121-reset' "
529 					"node in device tree!\n");
530 		return -ENODEV;
531 	}
532 
533 	rm = of_iomap(rmnode, 0);
534 	if (!rm) {
535 		dev_err(prv->dev, "Error mapping reset module node!\n");
536 		ret = -EBUSY;
537 		goto out;
538 	}
539 
540 	rcwh = in_be32(&rm->rcwhr);
541 
542 	/* Bit 6: NFC bus width */
543 	rcw_width = ((rcwh >> 6) & 0x1) ? 2 : 1;
544 
545 	/* Bit 7: NFC Page/Spare size */
546 	ps = (rcwh >> 7) & 0x1;
547 
548 	/* Bits [22:21]: ROM Location */
549 	romloc = (rcwh >> 21) & 0x3;
550 
551 	/* Decode RCW bits */
552 	switch ((ps << 2) | romloc) {
553 	case 0x00:
554 	case 0x01:
555 		rcw_pagesize = 512;
556 		rcw_sparesize = 16;
557 		break;
558 	case 0x02:
559 	case 0x03:
560 		rcw_pagesize = 4096;
561 		rcw_sparesize = 128;
562 		break;
563 	case 0x04:
564 	case 0x05:
565 		rcw_pagesize = 2048;
566 		rcw_sparesize = 64;
567 		break;
568 	case 0x06:
569 	case 0x07:
570 		rcw_pagesize = 4096;
571 		rcw_sparesize = 218;
572 		break;
573 	}
574 
575 	mtd->writesize = rcw_pagesize;
576 	mtd->oobsize = rcw_sparesize;
577 	if (rcw_width == 2)
578 		chip->options |= NAND_BUSWIDTH_16;
579 
580 	dev_notice(prv->dev, "Configured for "
581 				"%u-bit NAND, page size %u "
582 				"with %u spare.\n",
583 				rcw_width * 8, rcw_pagesize,
584 				rcw_sparesize);
585 	iounmap(rm);
586 out:
587 	of_node_put(rmnode);
588 	return ret;
589 }
590 
591 /* Free driver resources */
592 static void mpc5121_nfc_free(struct device *dev, struct mtd_info *mtd)
593 {
594 	struct nand_chip *chip = mtd_to_nand(mtd);
595 	struct mpc5121_nfc_prv *prv = nand_get_controller_data(chip);
596 
597 	if (prv->csreg)
598 		iounmap(prv->csreg);
599 }
600 
601 static int mpc5121_nfc_attach_chip(struct nand_chip *chip)
602 {
603 	if (chip->ecc.engine_type == NAND_ECC_ENGINE_TYPE_SOFT &&
604 	    chip->ecc.algo == NAND_ECC_ALGO_UNKNOWN)
605 		chip->ecc.algo = NAND_ECC_ALGO_HAMMING;
606 
607 	return 0;
608 }
609 
610 static const struct nand_controller_ops mpc5121_nfc_ops = {
611 	.attach_chip = mpc5121_nfc_attach_chip,
612 };
613 
614 static int mpc5121_nfc_probe(struct platform_device *op)
615 {
616 	struct device_node *dn = op->dev.of_node;
617 	struct clk *clk;
618 	struct device *dev = &op->dev;
619 	struct mpc5121_nfc_prv *prv;
620 	struct mtd_info *mtd;
621 	struct nand_chip *chip;
622 	const __be32 *chips_no;
623 	void __iomem *regs;
624 	int resettime = 0;
625 	int retval = 0;
626 	int rev, len;
627 	int irq;
628 
629 	/*
630 	 * Check SoC revision. This driver supports only NFC
631 	 * in MPC5121 revision 2 and MPC5123 revision 3.
632 	 */
633 	rev = (mfspr(SPRN_SVR) >> 4) & 0xF;
634 	if ((rev != 2) && (rev != 3)) {
635 		dev_err(dev, "SoC revision %u is not supported!\n", rev);
636 		return -ENXIO;
637 	}
638 
639 	regs = devm_platform_ioremap_resource(op, 0);
640 	if (IS_ERR(regs))
641 		return PTR_ERR(regs);
642 
643 	irq = platform_get_irq(op, 0);
644 	if (irq < 0)
645 		return irq;
646 
647 	prv = devm_kzalloc(dev, sizeof(*prv), GFP_KERNEL);
648 	if (!prv)
649 		return -ENOMEM;
650 
651 	chip = &prv->chip;
652 	mtd = nand_to_mtd(chip);
653 
654 	nand_controller_init(&prv->controller);
655 	prv->controller.ops = &mpc5121_nfc_ops;
656 	chip->controller = &prv->controller;
657 
658 	mtd->dev.parent = dev;
659 	nand_set_controller_data(chip, prv);
660 	nand_set_flash_node(chip, dn);
661 	prv->dev = dev;
662 
663 	/* Read NFC configuration from Reset Config Word */
664 	retval = mpc5121_nfc_read_hw_config(mtd);
665 	if (retval) {
666 		dev_err(dev, "Unable to read NFC config!\n");
667 		return retval;
668 	}
669 
670 	prv->irq = irq;
671 
672 	chips_no = of_get_property(dn, "chips", &len);
673 	if (!chips_no || len != sizeof(*chips_no)) {
674 		dev_err(dev, "Invalid/missing 'chips' property!\n");
675 		return -EINVAL;
676 	}
677 
678 	prv->regs = regs;
679 
680 	mtd->name = "MPC5121 NAND";
681 	chip->legacy.dev_ready = mpc5121_nfc_dev_ready;
682 	chip->legacy.cmdfunc = mpc5121_nfc_command;
683 	chip->legacy.read_byte = mpc5121_nfc_read_byte;
684 	chip->legacy.read_buf = mpc5121_nfc_read_buf;
685 	chip->legacy.write_buf = mpc5121_nfc_write_buf;
686 	chip->legacy.select_chip = mpc5121_nfc_select_chip;
687 	chip->legacy.set_features = nand_get_set_features_notsupp;
688 	chip->legacy.get_features = nand_get_set_features_notsupp;
689 	chip->bbt_options = NAND_BBT_USE_FLASH;
690 
691 	/* Support external chip-select logic on ADS5121 board */
692 	if (of_machine_is_compatible("fsl,mpc5121ads")) {
693 		retval = ads5121_chipselect_init(mtd);
694 		if (retval) {
695 			dev_err(dev, "Chipselect init error!\n");
696 			return retval;
697 		}
698 
699 		chip->legacy.select_chip = ads5121_select_chip;
700 	}
701 
702 	/* Enable NFC clock */
703 	clk = devm_clk_get_enabled(dev, "ipg");
704 	if (IS_ERR(clk)) {
705 		dev_err(dev, "Unable to acquire and enable NFC clock!\n");
706 		retval = PTR_ERR(clk);
707 		goto error;
708 	}
709 	prv->clk = clk;
710 
711 	/* Reset NAND Flash controller */
712 	nfc_set(mtd, NFC_CONFIG1, NFC_RESET);
713 	while (nfc_read(mtd, NFC_CONFIG1) & NFC_RESET) {
714 		if (resettime++ >= NFC_RESET_TIMEOUT) {
715 			dev_err(dev, "Timeout while resetting NFC!\n");
716 			retval = -EINVAL;
717 			goto error;
718 		}
719 
720 		udelay(1);
721 	}
722 
723 	/* Enable write to NFC memory */
724 	nfc_write(mtd, NFC_CONFIG, NFC_BLS_UNLOCKED);
725 
726 	/* Enable write to all NAND pages */
727 	nfc_write(mtd, NFC_UNLOCKSTART_BLK0, 0x0000);
728 	nfc_write(mtd, NFC_UNLOCKEND_BLK0, 0xFFFF);
729 	nfc_write(mtd, NFC_WRPROT, NFC_WPC_UNLOCK);
730 
731 	/*
732 	 * Setup NFC:
733 	 *	- Big Endian transfers,
734 	 *	- Interrupt after full page read/write.
735 	 */
736 	nfc_write(mtd, NFC_CONFIG1, NFC_BIG_ENDIAN | NFC_INT_MASK |
737 							NFC_FULL_PAGE_INT);
738 
739 	/* Set spare area size */
740 	nfc_write(mtd, NFC_SPAS, mtd->oobsize >> 1);
741 
742 	init_waitqueue_head(&prv->irq_waitq);
743 	retval = devm_request_irq(dev, prv->irq, &mpc5121_nfc_irq, 0, DRV_NAME,
744 									mtd);
745 	if (retval) {
746 		dev_err(dev, "Error requesting IRQ!\n");
747 		goto error;
748 	}
749 
750 	/*
751 	 * This driver assumes that the default ECC engine should be TYPE_SOFT.
752 	 * Set ->engine_type before registering the NAND devices in order to
753 	 * provide a driver specific default value.
754 	 */
755 	chip->ecc.engine_type = NAND_ECC_ENGINE_TYPE_SOFT;
756 
757 	/* Detect NAND chips */
758 	retval = nand_scan(chip, be32_to_cpup(chips_no));
759 	if (retval) {
760 		dev_err(dev, "NAND Flash not found !\n");
761 		goto error;
762 	}
763 
764 	/* Set erase block size */
765 	switch (mtd->erasesize / mtd->writesize) {
766 	case 32:
767 		nfc_set(mtd, NFC_CONFIG1, NFC_PPB_32);
768 		break;
769 
770 	case 64:
771 		nfc_set(mtd, NFC_CONFIG1, NFC_PPB_64);
772 		break;
773 
774 	case 128:
775 		nfc_set(mtd, NFC_CONFIG1, NFC_PPB_128);
776 		break;
777 
778 	case 256:
779 		nfc_set(mtd, NFC_CONFIG1, NFC_PPB_256);
780 		break;
781 
782 	default:
783 		dev_err(dev, "Unsupported NAND flash!\n");
784 		retval = -ENXIO;
785 		goto error;
786 	}
787 
788 	dev_set_drvdata(dev, mtd);
789 
790 	/* Register device in MTD */
791 	retval = mtd_device_register(mtd, NULL, 0);
792 	if (retval) {
793 		dev_err(dev, "Error adding MTD device!\n");
794 		goto error;
795 	}
796 
797 	return 0;
798 error:
799 	mpc5121_nfc_free(dev, mtd);
800 	return retval;
801 }
802 
803 static void mpc5121_nfc_remove(struct platform_device *op)
804 {
805 	struct device *dev = &op->dev;
806 	struct mtd_info *mtd = dev_get_drvdata(dev);
807 	int ret;
808 
809 	ret = mtd_device_unregister(mtd);
810 	WARN_ON(ret);
811 	nand_cleanup(mtd_to_nand(mtd));
812 	mpc5121_nfc_free(dev, mtd);
813 }
814 
815 static const struct of_device_id mpc5121_nfc_match[] = {
816 	{ .compatible = "fsl,mpc5121-nfc", },
817 	{},
818 };
819 MODULE_DEVICE_TABLE(of, mpc5121_nfc_match);
820 
821 static struct platform_driver mpc5121_nfc_driver = {
822 	.probe		= mpc5121_nfc_probe,
823 	.remove		= mpc5121_nfc_remove,
824 	.driver		= {
825 		.name = DRV_NAME,
826 		.of_match_table = mpc5121_nfc_match,
827 	},
828 };
829 
830 module_platform_driver(mpc5121_nfc_driver);
831 
832 MODULE_AUTHOR("Freescale Semiconductor, Inc.");
833 MODULE_DESCRIPTION("MPC5121 NAND MTD driver");
834 MODULE_LICENSE("GPL");
835