xref: /openbmc/linux/drivers/mtd/nand/raw/mpc5121_nfc.c (revision 2cf1c348)
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 mpc5121_nfc_prv *prv = nand_get_controller_data(nand);
295 	u8 v;
296 
297 	v = in_8(prv->csreg);
298 	v |= 0x0F;
299 
300 	if (chip >= 0) {
301 		mpc5121_nfc_select_chip(nand, 0);
302 		v &= ~(1 << chip);
303 	} else
304 		mpc5121_nfc_select_chip(nand, -1);
305 
306 	out_8(prv->csreg, v);
307 }
308 
309 /* Read NAND Ready/Busy signal */
310 static int mpc5121_nfc_dev_ready(struct nand_chip *nand)
311 {
312 	/*
313 	 * NFC handles ready/busy signal internally. Therefore, this function
314 	 * always returns status as ready.
315 	 */
316 	return 1;
317 }
318 
319 /* Write command to NAND flash */
320 static void mpc5121_nfc_command(struct nand_chip *chip, unsigned command,
321 				int column, int page)
322 {
323 	struct mtd_info *mtd = nand_to_mtd(chip);
324 	struct mpc5121_nfc_prv *prv = nand_get_controller_data(chip);
325 
326 	prv->column = (column >= 0) ? column : 0;
327 	prv->spareonly = 0;
328 
329 	switch (command) {
330 	case NAND_CMD_PAGEPROG:
331 		mpc5121_nfc_send_prog_page(mtd);
332 		break;
333 	/*
334 	 * NFC does not support sub-page reads and writes,
335 	 * so emulate them using full page transfers.
336 	 */
337 	case NAND_CMD_READ0:
338 		column = 0;
339 		break;
340 
341 	case NAND_CMD_READ1:
342 		prv->column += 256;
343 		command = NAND_CMD_READ0;
344 		column = 0;
345 		break;
346 
347 	case NAND_CMD_READOOB:
348 		prv->spareonly = 1;
349 		command = NAND_CMD_READ0;
350 		column = 0;
351 		break;
352 
353 	case NAND_CMD_SEQIN:
354 		mpc5121_nfc_command(chip, NAND_CMD_READ0, column, page);
355 		column = 0;
356 		break;
357 
358 	case NAND_CMD_ERASE1:
359 	case NAND_CMD_ERASE2:
360 	case NAND_CMD_READID:
361 	case NAND_CMD_STATUS:
362 		break;
363 
364 	default:
365 		return;
366 	}
367 
368 	mpc5121_nfc_send_cmd(mtd, command);
369 	mpc5121_nfc_addr_cycle(mtd, column, page);
370 
371 	switch (command) {
372 	case NAND_CMD_READ0:
373 		if (mtd->writesize > 512)
374 			mpc5121_nfc_send_cmd(mtd, NAND_CMD_READSTART);
375 		mpc5121_nfc_send_read_page(mtd);
376 		break;
377 
378 	case NAND_CMD_READID:
379 		mpc5121_nfc_send_read_id(mtd);
380 		break;
381 
382 	case NAND_CMD_STATUS:
383 		mpc5121_nfc_send_read_status(mtd);
384 		if (chip->options & NAND_BUSWIDTH_16)
385 			prv->column = 1;
386 		else
387 			prv->column = 0;
388 		break;
389 	}
390 }
391 
392 /* Copy data from/to NFC spare buffers. */
393 static void mpc5121_nfc_copy_spare(struct mtd_info *mtd, uint offset,
394 						u8 *buffer, uint size, int wr)
395 {
396 	struct nand_chip *nand = mtd_to_nand(mtd);
397 	struct mpc5121_nfc_prv *prv = nand_get_controller_data(nand);
398 	uint o, s, sbsize, blksize;
399 
400 	/*
401 	 * NAND spare area is available through NFC spare buffers.
402 	 * The NFC divides spare area into (page_size / 512) chunks.
403 	 * Each chunk is placed into separate spare memory area, using
404 	 * first (spare_size / num_of_chunks) bytes of the buffer.
405 	 *
406 	 * For NAND device in which the spare area is not divided fully
407 	 * by the number of chunks, number of used bytes in each spare
408 	 * buffer is rounded down to the nearest even number of bytes,
409 	 * and all remaining bytes are added to the last used spare area.
410 	 *
411 	 * For more information read section 26.6.10 of MPC5121e
412 	 * Microcontroller Reference Manual, Rev. 3.
413 	 */
414 
415 	/* Calculate number of valid bytes in each spare buffer */
416 	sbsize = (mtd->oobsize / (mtd->writesize / 512)) & ~1;
417 
418 	while (size) {
419 		/* Calculate spare buffer number */
420 		s = offset / sbsize;
421 		if (s > NFC_SPARE_BUFFERS - 1)
422 			s = NFC_SPARE_BUFFERS - 1;
423 
424 		/*
425 		 * Calculate offset to requested data block in selected spare
426 		 * buffer and its size.
427 		 */
428 		o = offset - (s * sbsize);
429 		blksize = min(sbsize - o, size);
430 
431 		if (wr)
432 			memcpy_toio(prv->regs + NFC_SPARE_AREA(s) + o,
433 							buffer, blksize);
434 		else
435 			memcpy_fromio(buffer,
436 				prv->regs + NFC_SPARE_AREA(s) + o, blksize);
437 
438 		buffer += blksize;
439 		offset += blksize;
440 		size -= blksize;
441 	}
442 }
443 
444 /* Copy data from/to NFC main and spare buffers */
445 static void mpc5121_nfc_buf_copy(struct mtd_info *mtd, u_char *buf, int len,
446 									int wr)
447 {
448 	struct nand_chip *chip = mtd_to_nand(mtd);
449 	struct mpc5121_nfc_prv *prv = nand_get_controller_data(chip);
450 	uint c = prv->column;
451 	uint l;
452 
453 	/* Handle spare area access */
454 	if (prv->spareonly || c >= mtd->writesize) {
455 		/* Calculate offset from beginning of spare area */
456 		if (c >= mtd->writesize)
457 			c -= mtd->writesize;
458 
459 		prv->column += len;
460 		mpc5121_nfc_copy_spare(mtd, c, buf, len, wr);
461 		return;
462 	}
463 
464 	/*
465 	 * Handle main area access - limit copy length to prevent
466 	 * crossing main/spare boundary.
467 	 */
468 	l = min((uint)len, mtd->writesize - c);
469 	prv->column += l;
470 
471 	if (wr)
472 		memcpy_toio(prv->regs + NFC_MAIN_AREA(0) + c, buf, l);
473 	else
474 		memcpy_fromio(buf, prv->regs + NFC_MAIN_AREA(0) + c, l);
475 
476 	/* Handle crossing main/spare boundary */
477 	if (l != len) {
478 		buf += l;
479 		len -= l;
480 		mpc5121_nfc_buf_copy(mtd, buf, len, wr);
481 	}
482 }
483 
484 /* Read data from NFC buffers */
485 static void mpc5121_nfc_read_buf(struct nand_chip *chip, u_char *buf, int len)
486 {
487 	mpc5121_nfc_buf_copy(nand_to_mtd(chip), buf, len, 0);
488 }
489 
490 /* Write data to NFC buffers */
491 static void mpc5121_nfc_write_buf(struct nand_chip *chip, const u_char *buf,
492 				  int len)
493 {
494 	mpc5121_nfc_buf_copy(nand_to_mtd(chip), (u_char *)buf, len, 1);
495 }
496 
497 /* Read byte from NFC buffers */
498 static u8 mpc5121_nfc_read_byte(struct nand_chip *chip)
499 {
500 	u8 tmp;
501 
502 	mpc5121_nfc_read_buf(chip, &tmp, sizeof(tmp));
503 
504 	return tmp;
505 }
506 
507 /*
508  * Read NFC configuration from Reset Config Word
509  *
510  * NFC is configured during reset in basis of information stored
511  * in Reset Config Word. There is no other way to set NAND block
512  * size, spare size and bus width.
513  */
514 static int mpc5121_nfc_read_hw_config(struct mtd_info *mtd)
515 {
516 	struct nand_chip *chip = mtd_to_nand(mtd);
517 	struct mpc5121_nfc_prv *prv = nand_get_controller_data(chip);
518 	struct mpc512x_reset_module *rm;
519 	struct device_node *rmnode;
520 	uint rcw_pagesize = 0;
521 	uint rcw_sparesize = 0;
522 	uint rcw_width;
523 	uint rcwh;
524 	uint romloc, ps;
525 	int ret = 0;
526 
527 	rmnode = of_find_compatible_node(NULL, NULL, "fsl,mpc5121-reset");
528 	if (!rmnode) {
529 		dev_err(prv->dev, "Missing 'fsl,mpc5121-reset' "
530 					"node in device tree!\n");
531 		return -ENODEV;
532 	}
533 
534 	rm = of_iomap(rmnode, 0);
535 	if (!rm) {
536 		dev_err(prv->dev, "Error mapping reset module node!\n");
537 		ret = -EBUSY;
538 		goto out;
539 	}
540 
541 	rcwh = in_be32(&rm->rcwhr);
542 
543 	/* Bit 6: NFC bus width */
544 	rcw_width = ((rcwh >> 6) & 0x1) ? 2 : 1;
545 
546 	/* Bit 7: NFC Page/Spare size */
547 	ps = (rcwh >> 7) & 0x1;
548 
549 	/* Bits [22:21]: ROM Location */
550 	romloc = (rcwh >> 21) & 0x3;
551 
552 	/* Decode RCW bits */
553 	switch ((ps << 2) | romloc) {
554 	case 0x00:
555 	case 0x01:
556 		rcw_pagesize = 512;
557 		rcw_sparesize = 16;
558 		break;
559 	case 0x02:
560 	case 0x03:
561 		rcw_pagesize = 4096;
562 		rcw_sparesize = 128;
563 		break;
564 	case 0x04:
565 	case 0x05:
566 		rcw_pagesize = 2048;
567 		rcw_sparesize = 64;
568 		break;
569 	case 0x06:
570 	case 0x07:
571 		rcw_pagesize = 4096;
572 		rcw_sparesize = 218;
573 		break;
574 	}
575 
576 	mtd->writesize = rcw_pagesize;
577 	mtd->oobsize = rcw_sparesize;
578 	if (rcw_width == 2)
579 		chip->options |= NAND_BUSWIDTH_16;
580 
581 	dev_notice(prv->dev, "Configured for "
582 				"%u-bit NAND, page size %u "
583 				"with %u spare.\n",
584 				rcw_width * 8, rcw_pagesize,
585 				rcw_sparesize);
586 	iounmap(rm);
587 out:
588 	of_node_put(rmnode);
589 	return ret;
590 }
591 
592 /* Free driver resources */
593 static void mpc5121_nfc_free(struct device *dev, struct mtd_info *mtd)
594 {
595 	struct nand_chip *chip = mtd_to_nand(mtd);
596 	struct mpc5121_nfc_prv *prv = nand_get_controller_data(chip);
597 
598 	if (prv->clk)
599 		clk_disable_unprepare(prv->clk);
600 
601 	if (prv->csreg)
602 		iounmap(prv->csreg);
603 }
604 
605 static int mpc5121_nfc_attach_chip(struct nand_chip *chip)
606 {
607 	if (chip->ecc.engine_type == NAND_ECC_ENGINE_TYPE_SOFT &&
608 	    chip->ecc.algo == NAND_ECC_ALGO_UNKNOWN)
609 		chip->ecc.algo = NAND_ECC_ALGO_HAMMING;
610 
611 	return 0;
612 }
613 
614 static const struct nand_controller_ops mpc5121_nfc_ops = {
615 	.attach_chip = mpc5121_nfc_attach_chip,
616 };
617 
618 static int mpc5121_nfc_probe(struct platform_device *op)
619 {
620 	struct device_node *dn = op->dev.of_node;
621 	struct clk *clk;
622 	struct device *dev = &op->dev;
623 	struct mpc5121_nfc_prv *prv;
624 	struct resource res;
625 	struct mtd_info *mtd;
626 	struct nand_chip *chip;
627 	unsigned long regs_paddr, regs_size;
628 	const __be32 *chips_no;
629 	int resettime = 0;
630 	int retval = 0;
631 	int rev, len;
632 
633 	/*
634 	 * Check SoC revision. This driver supports only NFC
635 	 * in MPC5121 revision 2 and MPC5123 revision 3.
636 	 */
637 	rev = (mfspr(SPRN_SVR) >> 4) & 0xF;
638 	if ((rev != 2) && (rev != 3)) {
639 		dev_err(dev, "SoC revision %u is not supported!\n", rev);
640 		return -ENXIO;
641 	}
642 
643 	prv = devm_kzalloc(dev, sizeof(*prv), GFP_KERNEL);
644 	if (!prv)
645 		return -ENOMEM;
646 
647 	chip = &prv->chip;
648 	mtd = nand_to_mtd(chip);
649 
650 	nand_controller_init(&prv->controller);
651 	prv->controller.ops = &mpc5121_nfc_ops;
652 	chip->controller = &prv->controller;
653 
654 	mtd->dev.parent = dev;
655 	nand_set_controller_data(chip, prv);
656 	nand_set_flash_node(chip, dn);
657 	prv->dev = dev;
658 
659 	/* Read NFC configuration from Reset Config Word */
660 	retval = mpc5121_nfc_read_hw_config(mtd);
661 	if (retval) {
662 		dev_err(dev, "Unable to read NFC config!\n");
663 		return retval;
664 	}
665 
666 	prv->irq = irq_of_parse_and_map(dn, 0);
667 	if (prv->irq == NO_IRQ) {
668 		dev_err(dev, "Error mapping IRQ!\n");
669 		return -EINVAL;
670 	}
671 
672 	retval = of_address_to_resource(dn, 0, &res);
673 	if (retval) {
674 		dev_err(dev, "Error parsing memory region!\n");
675 		return retval;
676 	}
677 
678 	chips_no = of_get_property(dn, "chips", &len);
679 	if (!chips_no || len != sizeof(*chips_no)) {
680 		dev_err(dev, "Invalid/missing 'chips' property!\n");
681 		return -EINVAL;
682 	}
683 
684 	regs_paddr = res.start;
685 	regs_size = resource_size(&res);
686 
687 	if (!devm_request_mem_region(dev, regs_paddr, regs_size, DRV_NAME)) {
688 		dev_err(dev, "Error requesting memory region!\n");
689 		return -EBUSY;
690 	}
691 
692 	prv->regs = devm_ioremap(dev, regs_paddr, regs_size);
693 	if (!prv->regs) {
694 		dev_err(dev, "Error mapping memory region!\n");
695 		return -ENOMEM;
696 	}
697 
698 	mtd->name = "MPC5121 NAND";
699 	chip->legacy.dev_ready = mpc5121_nfc_dev_ready;
700 	chip->legacy.cmdfunc = mpc5121_nfc_command;
701 	chip->legacy.read_byte = mpc5121_nfc_read_byte;
702 	chip->legacy.read_buf = mpc5121_nfc_read_buf;
703 	chip->legacy.write_buf = mpc5121_nfc_write_buf;
704 	chip->legacy.select_chip = mpc5121_nfc_select_chip;
705 	chip->legacy.set_features = nand_get_set_features_notsupp;
706 	chip->legacy.get_features = nand_get_set_features_notsupp;
707 	chip->bbt_options = NAND_BBT_USE_FLASH;
708 
709 	/* Support external chip-select logic on ADS5121 board */
710 	if (of_machine_is_compatible("fsl,mpc5121ads")) {
711 		retval = ads5121_chipselect_init(mtd);
712 		if (retval) {
713 			dev_err(dev, "Chipselect init error!\n");
714 			return retval;
715 		}
716 
717 		chip->legacy.select_chip = ads5121_select_chip;
718 	}
719 
720 	/* Enable NFC clock */
721 	clk = devm_clk_get(dev, "ipg");
722 	if (IS_ERR(clk)) {
723 		dev_err(dev, "Unable to acquire NFC clock!\n");
724 		retval = PTR_ERR(clk);
725 		goto error;
726 	}
727 	retval = clk_prepare_enable(clk);
728 	if (retval) {
729 		dev_err(dev, "Unable to enable NFC clock!\n");
730 		goto error;
731 	}
732 	prv->clk = clk;
733 
734 	/* Reset NAND Flash controller */
735 	nfc_set(mtd, NFC_CONFIG1, NFC_RESET);
736 	while (nfc_read(mtd, NFC_CONFIG1) & NFC_RESET) {
737 		if (resettime++ >= NFC_RESET_TIMEOUT) {
738 			dev_err(dev, "Timeout while resetting NFC!\n");
739 			retval = -EINVAL;
740 			goto error;
741 		}
742 
743 		udelay(1);
744 	}
745 
746 	/* Enable write to NFC memory */
747 	nfc_write(mtd, NFC_CONFIG, NFC_BLS_UNLOCKED);
748 
749 	/* Enable write to all NAND pages */
750 	nfc_write(mtd, NFC_UNLOCKSTART_BLK0, 0x0000);
751 	nfc_write(mtd, NFC_UNLOCKEND_BLK0, 0xFFFF);
752 	nfc_write(mtd, NFC_WRPROT, NFC_WPC_UNLOCK);
753 
754 	/*
755 	 * Setup NFC:
756 	 *	- Big Endian transfers,
757 	 *	- Interrupt after full page read/write.
758 	 */
759 	nfc_write(mtd, NFC_CONFIG1, NFC_BIG_ENDIAN | NFC_INT_MASK |
760 							NFC_FULL_PAGE_INT);
761 
762 	/* Set spare area size */
763 	nfc_write(mtd, NFC_SPAS, mtd->oobsize >> 1);
764 
765 	init_waitqueue_head(&prv->irq_waitq);
766 	retval = devm_request_irq(dev, prv->irq, &mpc5121_nfc_irq, 0, DRV_NAME,
767 									mtd);
768 	if (retval) {
769 		dev_err(dev, "Error requesting IRQ!\n");
770 		goto error;
771 	}
772 
773 	/*
774 	 * This driver assumes that the default ECC engine should be TYPE_SOFT.
775 	 * Set ->engine_type before registering the NAND devices in order to
776 	 * provide a driver specific default value.
777 	 */
778 	chip->ecc.engine_type = NAND_ECC_ENGINE_TYPE_SOFT;
779 
780 	/* Detect NAND chips */
781 	retval = nand_scan(chip, be32_to_cpup(chips_no));
782 	if (retval) {
783 		dev_err(dev, "NAND Flash not found !\n");
784 		goto error;
785 	}
786 
787 	/* Set erase block size */
788 	switch (mtd->erasesize / mtd->writesize) {
789 	case 32:
790 		nfc_set(mtd, NFC_CONFIG1, NFC_PPB_32);
791 		break;
792 
793 	case 64:
794 		nfc_set(mtd, NFC_CONFIG1, NFC_PPB_64);
795 		break;
796 
797 	case 128:
798 		nfc_set(mtd, NFC_CONFIG1, NFC_PPB_128);
799 		break;
800 
801 	case 256:
802 		nfc_set(mtd, NFC_CONFIG1, NFC_PPB_256);
803 		break;
804 
805 	default:
806 		dev_err(dev, "Unsupported NAND flash!\n");
807 		retval = -ENXIO;
808 		goto error;
809 	}
810 
811 	dev_set_drvdata(dev, mtd);
812 
813 	/* Register device in MTD */
814 	retval = mtd_device_register(mtd, NULL, 0);
815 	if (retval) {
816 		dev_err(dev, "Error adding MTD device!\n");
817 		goto error;
818 	}
819 
820 	return 0;
821 error:
822 	mpc5121_nfc_free(dev, mtd);
823 	return retval;
824 }
825 
826 static int mpc5121_nfc_remove(struct platform_device *op)
827 {
828 	struct device *dev = &op->dev;
829 	struct mtd_info *mtd = dev_get_drvdata(dev);
830 	int ret;
831 
832 	ret = mtd_device_unregister(mtd);
833 	WARN_ON(ret);
834 	nand_cleanup(mtd_to_nand(mtd));
835 	mpc5121_nfc_free(dev, mtd);
836 
837 	return 0;
838 }
839 
840 static const struct of_device_id mpc5121_nfc_match[] = {
841 	{ .compatible = "fsl,mpc5121-nfc", },
842 	{},
843 };
844 MODULE_DEVICE_TABLE(of, mpc5121_nfc_match);
845 
846 static struct platform_driver mpc5121_nfc_driver = {
847 	.probe		= mpc5121_nfc_probe,
848 	.remove		= mpc5121_nfc_remove,
849 	.driver		= {
850 		.name = DRV_NAME,
851 		.of_match_table = mpc5121_nfc_match,
852 	},
853 };
854 
855 module_platform_driver(mpc5121_nfc_driver);
856 
857 MODULE_AUTHOR("Freescale Semiconductor, Inc.");
858 MODULE_DESCRIPTION("MPC5121 NAND MTD driver");
859 MODULE_LICENSE("GPL");
860