xref: /openbmc/u-boot/drivers/mtd/nand/raw/vf610_nfc.c (revision 6c6add60)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright 2009-2015 Freescale Semiconductor, Inc. and others
4  *
5  * Description: MPC5125, VF610, MCF54418 and Kinetis K70 Nand driver.
6  * Ported to U-Boot by Stefan Agner
7  * Based on RFC driver posted on Kernel Mailing list by Bill Pringlemeir
8  * Jason ported to M54418TWR and MVFA5.
9  * Authors: Stefan Agner <stefan.agner@toradex.com>
10  *          Bill Pringlemeir <bpringlemeir@nbsps.com>
11  *          Shaohui Xie <b21989@freescale.com>
12  *          Jason Jin <Jason.jin@freescale.com>
13  *
14  * Based on original driver mpc5121_nfc.c.
15  *
16  * Limitations:
17  * - Untested on MPC5125 and M54418.
18  * - DMA and pipelining not used.
19  * - 2K pages or less.
20  * - HW ECC: Only 2K page with 64+ OOB.
21  * - HW ECC: Only 24 and 32-bit error correction implemented.
22  */
23 
24 #include <common.h>
25 #include <malloc.h>
26 
27 #include <linux/mtd/mtd.h>
28 #include <linux/mtd/rawnand.h>
29 #include <linux/mtd/partitions.h>
30 
31 #include <nand.h>
32 #include <errno.h>
33 #include <asm/io.h>
34 
35 /* Register Offsets */
36 #define NFC_FLASH_CMD1			0x3F00
37 #define NFC_FLASH_CMD2			0x3F04
38 #define NFC_COL_ADDR			0x3F08
39 #define NFC_ROW_ADDR			0x3F0c
40 #define NFC_ROW_ADDR_INC		0x3F14
41 #define NFC_FLASH_STATUS1		0x3F18
42 #define NFC_FLASH_STATUS2		0x3F1c
43 #define NFC_CACHE_SWAP			0x3F28
44 #define NFC_SECTOR_SIZE			0x3F2c
45 #define NFC_FLASH_CONFIG		0x3F30
46 #define NFC_IRQ_STATUS			0x3F38
47 
48 /* Addresses for NFC MAIN RAM BUFFER areas */
49 #define NFC_MAIN_AREA(n)		((n) *  0x1000)
50 
51 #define PAGE_2K				0x0800
52 #define OOB_64				0x0040
53 #define OOB_MAX				0x0100
54 
55 /*
56  * NFC_CMD2[CODE] values. See section:
57  *  - 31.4.7 Flash Command Code Description, Vybrid manual
58  *  - 23.8.6 Flash Command Sequencer, MPC5125 manual
59  *
60  * Briefly these are bitmasks of controller cycles.
61  */
62 #define READ_PAGE_CMD_CODE		0x7EE0
63 #define READ_ONFI_PARAM_CMD_CODE	0x4860
64 #define PROGRAM_PAGE_CMD_CODE		0x7FC0
65 #define ERASE_CMD_CODE			0x4EC0
66 #define READ_ID_CMD_CODE		0x4804
67 #define RESET_CMD_CODE			0x4040
68 #define STATUS_READ_CMD_CODE		0x4068
69 
70 /* NFC ECC mode define */
71 #define ECC_BYPASS			0
72 #define ECC_45_BYTE			6
73 #define ECC_60_BYTE			7
74 
75 /*** Register Mask and bit definitions */
76 
77 /* NFC_FLASH_CMD1 Field */
78 #define CMD_BYTE2_MASK				0xFF000000
79 #define CMD_BYTE2_SHIFT				24
80 
81 /* NFC_FLASH_CM2 Field */
82 #define CMD_BYTE1_MASK				0xFF000000
83 #define CMD_BYTE1_SHIFT				24
84 #define CMD_CODE_MASK				0x00FFFF00
85 #define CMD_CODE_SHIFT				8
86 #define BUFNO_MASK				0x00000006
87 #define BUFNO_SHIFT				1
88 #define START_BIT				(1<<0)
89 
90 /* NFC_COL_ADDR Field */
91 #define COL_ADDR_MASK				0x0000FFFF
92 #define COL_ADDR_SHIFT				0
93 
94 /* NFC_ROW_ADDR Field */
95 #define ROW_ADDR_MASK				0x00FFFFFF
96 #define ROW_ADDR_SHIFT				0
97 #define ROW_ADDR_CHIP_SEL_RB_MASK		0xF0000000
98 #define ROW_ADDR_CHIP_SEL_RB_SHIFT		28
99 #define ROW_ADDR_CHIP_SEL_MASK			0x0F000000
100 #define ROW_ADDR_CHIP_SEL_SHIFT			24
101 
102 /* NFC_FLASH_STATUS2 Field */
103 #define STATUS_BYTE1_MASK			0x000000FF
104 
105 /* NFC_FLASH_CONFIG Field */
106 #define CONFIG_ECC_SRAM_ADDR_MASK		0x7FC00000
107 #define CONFIG_ECC_SRAM_ADDR_SHIFT		22
108 #define CONFIG_ECC_SRAM_REQ_BIT			(1<<21)
109 #define CONFIG_DMA_REQ_BIT			(1<<20)
110 #define CONFIG_ECC_MODE_MASK			0x000E0000
111 #define CONFIG_ECC_MODE_SHIFT			17
112 #define CONFIG_FAST_FLASH_BIT			(1<<16)
113 #define CONFIG_16BIT				(1<<7)
114 #define CONFIG_BOOT_MODE_BIT			(1<<6)
115 #define CONFIG_ADDR_AUTO_INCR_BIT		(1<<5)
116 #define CONFIG_BUFNO_AUTO_INCR_BIT		(1<<4)
117 #define CONFIG_PAGE_CNT_MASK			0xF
118 #define CONFIG_PAGE_CNT_SHIFT			0
119 
120 /* NFC_IRQ_STATUS Field */
121 #define IDLE_IRQ_BIT				(1<<29)
122 #define IDLE_EN_BIT				(1<<20)
123 #define CMD_DONE_CLEAR_BIT			(1<<18)
124 #define IDLE_CLEAR_BIT				(1<<17)
125 
126 #define NFC_TIMEOUT	(1000)
127 
128 /*
129  * ECC status - seems to consume 8 bytes (double word). The documented
130  * status byte is located in the lowest byte of the second word (which is
131  * the 4th or 7th byte depending on endianness).
132  * Calculate an offset to store the ECC status at the end of the buffer.
133  */
134 #define ECC_SRAM_ADDR		(PAGE_2K + OOB_MAX - 8)
135 
136 #define ECC_STATUS		0x4
137 #define ECC_STATUS_MASK		0x80
138 #define ECC_STATUS_ERR_COUNT	0x3F
139 
140 enum vf610_nfc_alt_buf {
141 	ALT_BUF_DATA = 0,
142 	ALT_BUF_ID = 1,
143 	ALT_BUF_STAT = 2,
144 	ALT_BUF_ONFI = 3,
145 };
146 
147 struct vf610_nfc {
148 	struct nand_chip chip;
149 	void __iomem *regs;
150 	uint buf_offset;
151 	int write_sz;
152 	/* Status and ID are in alternate locations. */
153 	enum vf610_nfc_alt_buf alt_buf;
154 };
155 
156 #define mtd_to_nfc(_mtd) nand_get_controller_data(mtd_to_nand(_mtd))
157 
158 #if defined(CONFIG_SYS_NAND_VF610_NFC_45_ECC_BYTES)
159 #define ECC_HW_MODE ECC_45_BYTE
160 
161 static struct nand_ecclayout vf610_nfc_ecc = {
162 	.eccbytes = 45,
163 	.eccpos = {19, 20, 21, 22, 23,
164 		   24, 25, 26, 27, 28, 29, 30, 31,
165 		   32, 33, 34, 35, 36, 37, 38, 39,
166 		   40, 41, 42, 43, 44, 45, 46, 47,
167 		   48, 49, 50, 51, 52, 53, 54, 55,
168 		   56, 57, 58, 59, 60, 61, 62, 63},
169 	.oobfree = {
170 		{.offset = 2,
171 		 .length = 17} }
172 };
173 #elif defined(CONFIG_SYS_NAND_VF610_NFC_60_ECC_BYTES)
174 #define ECC_HW_MODE ECC_60_BYTE
175 
176 static struct nand_ecclayout vf610_nfc_ecc = {
177 	.eccbytes = 60,
178 	.eccpos = { 4,  5,  6,  7,  8,  9, 10, 11,
179 		   12, 13, 14, 15, 16, 17, 18, 19,
180 		   20, 21, 22, 23, 24, 25, 26, 27,
181 		   28, 29, 30, 31, 32, 33, 34, 35,
182 		   36, 37, 38, 39, 40, 41, 42, 43,
183 		   44, 45, 46, 47, 48, 49, 50, 51,
184 		   52, 53, 54, 55, 56, 57, 58, 59,
185 		   60, 61, 62, 63 },
186 	.oobfree = {
187 		{.offset = 2,
188 		 .length = 2} }
189 };
190 #endif
191 
192 static inline u32 vf610_nfc_read(struct mtd_info *mtd, uint reg)
193 {
194 	struct vf610_nfc *nfc = mtd_to_nfc(mtd);
195 
196 	return readl(nfc->regs + reg);
197 }
198 
199 static inline void vf610_nfc_write(struct mtd_info *mtd, uint reg, u32 val)
200 {
201 	struct vf610_nfc *nfc = mtd_to_nfc(mtd);
202 
203 	writel(val, nfc->regs + reg);
204 }
205 
206 static inline void vf610_nfc_set(struct mtd_info *mtd, uint reg, u32 bits)
207 {
208 	vf610_nfc_write(mtd, reg, vf610_nfc_read(mtd, reg) | bits);
209 }
210 
211 static inline void vf610_nfc_clear(struct mtd_info *mtd, uint reg, u32 bits)
212 {
213 	vf610_nfc_write(mtd, reg, vf610_nfc_read(mtd, reg) & ~bits);
214 }
215 
216 static inline void vf610_nfc_set_field(struct mtd_info *mtd, u32 reg,
217 				       u32 mask, u32 shift, u32 val)
218 {
219 	vf610_nfc_write(mtd, reg,
220 			(vf610_nfc_read(mtd, reg) & (~mask)) | val << shift);
221 }
222 
223 static inline void vf610_nfc_memcpy(void *dst, const void *src, size_t n)
224 {
225 	/*
226 	 * Use this accessor for the internal SRAM buffers. On the ARM
227 	 * Freescale Vybrid SoC it's known that the driver can treat
228 	 * the SRAM buffer as if it's memory. Other platform might need
229 	 * to treat the buffers differently.
230 	 *
231 	 * For the time being, use memcpy
232 	 */
233 	memcpy(dst, src, n);
234 }
235 
236 /* Clear flags for upcoming command */
237 static inline void vf610_nfc_clear_status(void __iomem *regbase)
238 {
239 	void __iomem *reg = regbase + NFC_IRQ_STATUS;
240 	u32 tmp = __raw_readl(reg);
241 	tmp |= CMD_DONE_CLEAR_BIT | IDLE_CLEAR_BIT;
242 	__raw_writel(tmp, reg);
243 }
244 
245 /* Wait for complete operation */
246 static void vf610_nfc_done(struct mtd_info *mtd)
247 {
248 	struct vf610_nfc *nfc = mtd_to_nfc(mtd);
249 	uint start;
250 
251 	/*
252 	 * Barrier is needed after this write. This write need
253 	 * to be done before reading the next register the first
254 	 * time.
255 	 * vf610_nfc_set implicates such a barrier by using writel
256 	 * to write to the register.
257 	 */
258 	vf610_nfc_set(mtd, NFC_FLASH_CMD2, START_BIT);
259 
260 	start = get_timer(0);
261 
262 	while (!(vf610_nfc_read(mtd, NFC_IRQ_STATUS) & IDLE_IRQ_BIT)) {
263 		if (get_timer(start) > NFC_TIMEOUT) {
264 			printf("Timeout while waiting for IDLE.\n");
265 			return;
266 		}
267 	}
268 	vf610_nfc_clear_status(nfc->regs);
269 }
270 
271 static u8 vf610_nfc_get_id(struct mtd_info *mtd, int col)
272 {
273 	u32 flash_id;
274 
275 	if (col < 4) {
276 		flash_id = vf610_nfc_read(mtd, NFC_FLASH_STATUS1);
277 		flash_id >>= (3 - col) * 8;
278 	} else {
279 		flash_id = vf610_nfc_read(mtd, NFC_FLASH_STATUS2);
280 		flash_id >>= 24;
281 	}
282 
283 	return flash_id & 0xff;
284 }
285 
286 static u8 vf610_nfc_get_status(struct mtd_info *mtd)
287 {
288 	return vf610_nfc_read(mtd, NFC_FLASH_STATUS2) & STATUS_BYTE1_MASK;
289 }
290 
291 /* Single command */
292 static void vf610_nfc_send_command(void __iomem *regbase, u32 cmd_byte1,
293 				   u32 cmd_code)
294 {
295 	void __iomem *reg = regbase + NFC_FLASH_CMD2;
296 	u32 tmp;
297 	vf610_nfc_clear_status(regbase);
298 
299 	tmp = __raw_readl(reg);
300 	tmp &= ~(CMD_BYTE1_MASK | CMD_CODE_MASK | BUFNO_MASK);
301 	tmp |= cmd_byte1 << CMD_BYTE1_SHIFT;
302 	tmp |= cmd_code << CMD_CODE_SHIFT;
303 	__raw_writel(tmp, reg);
304 }
305 
306 /* Two commands */
307 static void vf610_nfc_send_commands(void __iomem *regbase, u32 cmd_byte1,
308 			      u32 cmd_byte2, u32 cmd_code)
309 {
310 	void __iomem *reg = regbase + NFC_FLASH_CMD1;
311 	u32 tmp;
312 	vf610_nfc_send_command(regbase, cmd_byte1, cmd_code);
313 
314 	tmp = __raw_readl(reg);
315 	tmp &= ~CMD_BYTE2_MASK;
316 	tmp |= cmd_byte2 << CMD_BYTE2_SHIFT;
317 	__raw_writel(tmp, reg);
318 }
319 
320 static void vf610_nfc_addr_cycle(struct mtd_info *mtd, int column, int page)
321 {
322 	if (column != -1) {
323 		struct vf610_nfc *nfc = mtd_to_nfc(mtd);
324 		if (nfc->chip.options & NAND_BUSWIDTH_16)
325 			column = column / 2;
326 		vf610_nfc_set_field(mtd, NFC_COL_ADDR, COL_ADDR_MASK,
327 				    COL_ADDR_SHIFT, column);
328 	}
329 	if (page != -1)
330 		vf610_nfc_set_field(mtd, NFC_ROW_ADDR, ROW_ADDR_MASK,
331 				    ROW_ADDR_SHIFT, page);
332 }
333 
334 static inline void vf610_nfc_ecc_mode(struct mtd_info *mtd, int ecc_mode)
335 {
336 	vf610_nfc_set_field(mtd, NFC_FLASH_CONFIG,
337 			    CONFIG_ECC_MODE_MASK,
338 			    CONFIG_ECC_MODE_SHIFT, ecc_mode);
339 }
340 
341 static inline void vf610_nfc_transfer_size(void __iomem *regbase, int size)
342 {
343 	__raw_writel(size, regbase + NFC_SECTOR_SIZE);
344 }
345 
346 /* Send command to NAND chip */
347 static void vf610_nfc_command(struct mtd_info *mtd, unsigned command,
348 			      int column, int page)
349 {
350 	struct vf610_nfc *nfc = mtd_to_nfc(mtd);
351 	int trfr_sz = nfc->chip.options & NAND_BUSWIDTH_16 ? 1 : 0;
352 
353 	nfc->buf_offset = max(column, 0);
354 	nfc->alt_buf = ALT_BUF_DATA;
355 
356 	switch (command) {
357 	case NAND_CMD_SEQIN:
358 		/* Use valid column/page from preread... */
359 		vf610_nfc_addr_cycle(mtd, column, page);
360 		nfc->buf_offset = 0;
361 
362 		/*
363 		 * SEQIN => data => PAGEPROG sequence is done by the controller
364 		 * hence we do not need to issue the command here...
365 		 */
366 		return;
367 	case NAND_CMD_PAGEPROG:
368 		trfr_sz += nfc->write_sz;
369 		vf610_nfc_ecc_mode(mtd, ECC_HW_MODE);
370 		vf610_nfc_transfer_size(nfc->regs, trfr_sz);
371 		vf610_nfc_send_commands(nfc->regs, NAND_CMD_SEQIN,
372 					command, PROGRAM_PAGE_CMD_CODE);
373 		break;
374 
375 	case NAND_CMD_RESET:
376 		vf610_nfc_transfer_size(nfc->regs, 0);
377 		vf610_nfc_send_command(nfc->regs, command, RESET_CMD_CODE);
378 		break;
379 
380 	case NAND_CMD_READOOB:
381 		trfr_sz += mtd->oobsize;
382 		column = mtd->writesize;
383 		vf610_nfc_transfer_size(nfc->regs, trfr_sz);
384 		vf610_nfc_send_commands(nfc->regs, NAND_CMD_READ0,
385 					NAND_CMD_READSTART, READ_PAGE_CMD_CODE);
386 		vf610_nfc_addr_cycle(mtd, column, page);
387 		vf610_nfc_ecc_mode(mtd, ECC_BYPASS);
388 		break;
389 
390 	case NAND_CMD_READ0:
391 		trfr_sz += mtd->writesize + mtd->oobsize;
392 		vf610_nfc_transfer_size(nfc->regs, trfr_sz);
393 		vf610_nfc_ecc_mode(mtd, ECC_HW_MODE);
394 		vf610_nfc_send_commands(nfc->regs, NAND_CMD_READ0,
395 					NAND_CMD_READSTART, READ_PAGE_CMD_CODE);
396 		vf610_nfc_addr_cycle(mtd, column, page);
397 		break;
398 
399 	case NAND_CMD_PARAM:
400 		nfc->alt_buf = ALT_BUF_ONFI;
401 		trfr_sz = 3 * sizeof(struct nand_onfi_params);
402 		vf610_nfc_transfer_size(nfc->regs, trfr_sz);
403 		vf610_nfc_send_command(nfc->regs, NAND_CMD_PARAM,
404 				       READ_ONFI_PARAM_CMD_CODE);
405 		vf610_nfc_set_field(mtd, NFC_ROW_ADDR, ROW_ADDR_MASK,
406 				    ROW_ADDR_SHIFT, column);
407 		vf610_nfc_ecc_mode(mtd, ECC_BYPASS);
408 		break;
409 
410 	case NAND_CMD_ERASE1:
411 		vf610_nfc_transfer_size(nfc->regs, 0);
412 		vf610_nfc_send_commands(nfc->regs, command,
413 					NAND_CMD_ERASE2, ERASE_CMD_CODE);
414 		vf610_nfc_addr_cycle(mtd, column, page);
415 		break;
416 
417 	case NAND_CMD_READID:
418 		nfc->alt_buf = ALT_BUF_ID;
419 		nfc->buf_offset = 0;
420 		vf610_nfc_transfer_size(nfc->regs, 0);
421 		vf610_nfc_send_command(nfc->regs, command, READ_ID_CMD_CODE);
422 		vf610_nfc_set_field(mtd, NFC_ROW_ADDR, ROW_ADDR_MASK,
423 				    ROW_ADDR_SHIFT, column);
424 		break;
425 
426 	case NAND_CMD_STATUS:
427 		nfc->alt_buf = ALT_BUF_STAT;
428 		vf610_nfc_transfer_size(nfc->regs, 0);
429 		vf610_nfc_send_command(nfc->regs, command, STATUS_READ_CMD_CODE);
430 		break;
431 	default:
432 		return;
433 	}
434 
435 	vf610_nfc_done(mtd);
436 
437 	nfc->write_sz = 0;
438 }
439 
440 /* Read data from NFC buffers */
441 static void vf610_nfc_read_buf(struct mtd_info *mtd, u_char *buf, int len)
442 {
443 	struct vf610_nfc *nfc = mtd_to_nfc(mtd);
444 	uint c = nfc->buf_offset;
445 
446 	/* Alternate buffers are only supported through read_byte */
447 	if (nfc->alt_buf)
448 		return;
449 
450 	vf610_nfc_memcpy(buf, nfc->regs + NFC_MAIN_AREA(0) + c, len);
451 
452 	nfc->buf_offset += len;
453 }
454 
455 /* Write data to NFC buffers */
456 static void vf610_nfc_write_buf(struct mtd_info *mtd, const uint8_t *buf,
457 				int len)
458 {
459 	struct vf610_nfc *nfc = mtd_to_nfc(mtd);
460 	uint c = nfc->buf_offset;
461 	uint l;
462 
463 	l = min_t(uint, len, mtd->writesize + mtd->oobsize - c);
464 	vf610_nfc_memcpy(nfc->regs + NFC_MAIN_AREA(0) + c, buf, l);
465 
466 	nfc->write_sz += l;
467 	nfc->buf_offset += l;
468 }
469 
470 /* Read byte from NFC buffers */
471 static uint8_t vf610_nfc_read_byte(struct mtd_info *mtd)
472 {
473 	struct vf610_nfc *nfc = mtd_to_nfc(mtd);
474 	u8 tmp;
475 	uint c = nfc->buf_offset;
476 
477 	switch (nfc->alt_buf) {
478 	case ALT_BUF_ID:
479 		tmp = vf610_nfc_get_id(mtd, c);
480 		break;
481 	case ALT_BUF_STAT:
482 		tmp = vf610_nfc_get_status(mtd);
483 		break;
484 #ifdef __LITTLE_ENDIAN
485 	case ALT_BUF_ONFI:
486 		/* Reverse byte since the controller uses big endianness */
487 		c = nfc->buf_offset ^ 0x3;
488 		/* fall-through */
489 #endif
490 	default:
491 		tmp = *((u8 *)(nfc->regs + NFC_MAIN_AREA(0) + c));
492 		break;
493 	}
494 	nfc->buf_offset++;
495 	return tmp;
496 }
497 
498 /* Read word from NFC buffers */
499 static u16 vf610_nfc_read_word(struct mtd_info *mtd)
500 {
501 	u16 tmp;
502 
503 	vf610_nfc_read_buf(mtd, (u_char *)&tmp, sizeof(tmp));
504 	return tmp;
505 }
506 
507 /* If not provided, upper layers apply a fixed delay. */
508 static int vf610_nfc_dev_ready(struct mtd_info *mtd)
509 {
510 	/* NFC handles R/B internally; always ready.  */
511 	return 1;
512 }
513 
514 /*
515  * This function supports Vybrid only (MPC5125 would have full RB and four CS)
516  */
517 static void vf610_nfc_select_chip(struct mtd_info *mtd, int chip)
518 {
519 #ifdef CONFIG_VF610
520 	u32 tmp = vf610_nfc_read(mtd, NFC_ROW_ADDR);
521 	tmp &= ~(ROW_ADDR_CHIP_SEL_RB_MASK | ROW_ADDR_CHIP_SEL_MASK);
522 
523 	if (chip >= 0) {
524 		tmp |= 1 << ROW_ADDR_CHIP_SEL_RB_SHIFT;
525 		tmp |= (1 << chip) << ROW_ADDR_CHIP_SEL_SHIFT;
526 	}
527 
528 	vf610_nfc_write(mtd, NFC_ROW_ADDR, tmp);
529 #endif
530 }
531 
532 /* Count the number of 0's in buff upto max_bits */
533 static inline int count_written_bits(uint8_t *buff, int size, int max_bits)
534 {
535 	uint32_t *buff32 = (uint32_t *)buff;
536 	int k, written_bits = 0;
537 
538 	for (k = 0; k < (size / 4); k++) {
539 		written_bits += hweight32(~buff32[k]);
540 		if (written_bits > max_bits)
541 			break;
542 	}
543 
544 	return written_bits;
545 }
546 
547 static inline int vf610_nfc_correct_data(struct mtd_info *mtd, uint8_t *dat,
548 					 uint8_t *oob, int page)
549 {
550 	struct vf610_nfc *nfc = mtd_to_nfc(mtd);
551 	u32 ecc_status_off = NFC_MAIN_AREA(0) + ECC_SRAM_ADDR + ECC_STATUS;
552 	u8 ecc_status;
553 	u8 ecc_count;
554 	int flips;
555 	int flips_threshold = nfc->chip.ecc.strength / 2;
556 
557 	ecc_status = vf610_nfc_read(mtd, ecc_status_off) & 0xff;
558 	ecc_count = ecc_status & ECC_STATUS_ERR_COUNT;
559 
560 	if (!(ecc_status & ECC_STATUS_MASK))
561 		return ecc_count;
562 
563 	/* Read OOB without ECC unit enabled */
564 	vf610_nfc_command(mtd, NAND_CMD_READOOB, 0, page);
565 	vf610_nfc_read_buf(mtd, oob, mtd->oobsize);
566 
567 	/*
568 	 * On an erased page, bit count (including OOB) should be zero or
569 	 * at least less then half of the ECC strength.
570 	 */
571 	flips = count_written_bits(dat, nfc->chip.ecc.size, flips_threshold);
572 	flips += count_written_bits(oob, mtd->oobsize, flips_threshold);
573 
574 	if (unlikely(flips > flips_threshold))
575 		return -EINVAL;
576 
577 	/* Erased page. */
578 	memset(dat, 0xff, nfc->chip.ecc.size);
579 	memset(oob, 0xff, mtd->oobsize);
580 	return flips;
581 }
582 
583 static int vf610_nfc_read_page(struct mtd_info *mtd, struct nand_chip *chip,
584 				uint8_t *buf, int oob_required, int page)
585 {
586 	int eccsize = chip->ecc.size;
587 	int stat;
588 
589 	vf610_nfc_read_buf(mtd, buf, eccsize);
590 	if (oob_required)
591 		vf610_nfc_read_buf(mtd, chip->oob_poi, mtd->oobsize);
592 
593 	stat = vf610_nfc_correct_data(mtd, buf, chip->oob_poi, page);
594 
595 	if (stat < 0) {
596 		mtd->ecc_stats.failed++;
597 		return 0;
598 	} else {
599 		mtd->ecc_stats.corrected += stat;
600 		return stat;
601 	}
602 }
603 
604 /*
605  * ECC will be calculated automatically
606  */
607 static int vf610_nfc_write_page(struct mtd_info *mtd, struct nand_chip *chip,
608 			       const uint8_t *buf, int oob_required, int page)
609 {
610 	struct vf610_nfc *nfc = mtd_to_nfc(mtd);
611 
612 	vf610_nfc_write_buf(mtd, buf, mtd->writesize);
613 	if (oob_required)
614 		vf610_nfc_write_buf(mtd, chip->oob_poi, mtd->oobsize);
615 
616 	/* Always write whole page including OOB due to HW ECC */
617 	nfc->write_sz = mtd->writesize + mtd->oobsize;
618 
619 	return 0;
620 }
621 
622 struct vf610_nfc_config {
623 	int hardware_ecc;
624 	int width;
625 	int flash_bbt;
626 };
627 
628 static int vf610_nfc_nand_init(int devnum, void __iomem *addr)
629 {
630 	struct mtd_info *mtd;
631 	struct nand_chip *chip;
632 	struct vf610_nfc *nfc;
633 	int err = 0;
634 	struct vf610_nfc_config cfg = {
635 		.hardware_ecc = 1,
636 #ifdef CONFIG_SYS_NAND_BUSWIDTH_16BIT
637 		.width = 16,
638 #else
639 		.width = 8,
640 #endif
641 		.flash_bbt = 1,
642 	};
643 
644 	nfc = malloc(sizeof(*nfc));
645 	if (!nfc) {
646 		printf(KERN_ERR "%s: Memory exhausted!\n", __func__);
647 		return -ENOMEM;
648 	}
649 
650 	chip = &nfc->chip;
651 	nfc->regs = addr;
652 
653 	mtd = nand_to_mtd(chip);
654 	nand_set_controller_data(chip, nfc);
655 
656 	if (cfg.width == 16)
657 		chip->options |= NAND_BUSWIDTH_16;
658 
659 	chip->dev_ready = vf610_nfc_dev_ready;
660 	chip->cmdfunc = vf610_nfc_command;
661 	chip->read_byte = vf610_nfc_read_byte;
662 	chip->read_word = vf610_nfc_read_word;
663 	chip->read_buf = vf610_nfc_read_buf;
664 	chip->write_buf = vf610_nfc_write_buf;
665 	chip->select_chip = vf610_nfc_select_chip;
666 
667 	chip->options |= NAND_NO_SUBPAGE_WRITE;
668 
669 	chip->ecc.size = PAGE_2K;
670 
671 	/* Set configuration register. */
672 	vf610_nfc_clear(mtd, NFC_FLASH_CONFIG, CONFIG_16BIT);
673 	vf610_nfc_clear(mtd, NFC_FLASH_CONFIG, CONFIG_ADDR_AUTO_INCR_BIT);
674 	vf610_nfc_clear(mtd, NFC_FLASH_CONFIG, CONFIG_BUFNO_AUTO_INCR_BIT);
675 	vf610_nfc_clear(mtd, NFC_FLASH_CONFIG, CONFIG_BOOT_MODE_BIT);
676 	vf610_nfc_clear(mtd, NFC_FLASH_CONFIG, CONFIG_DMA_REQ_BIT);
677 	vf610_nfc_set(mtd, NFC_FLASH_CONFIG, CONFIG_FAST_FLASH_BIT);
678 
679 	/* Disable virtual pages, only one elementary transfer unit */
680 	vf610_nfc_set_field(mtd, NFC_FLASH_CONFIG, CONFIG_PAGE_CNT_MASK,
681 			    CONFIG_PAGE_CNT_SHIFT, 1);
682 
683 	/* first scan to find the device and get the page size */
684 	if (nand_scan_ident(mtd, CONFIG_SYS_MAX_NAND_DEVICE, NULL)) {
685 		err = -ENXIO;
686 		goto error;
687 	}
688 
689 	if (cfg.width == 16)
690 		vf610_nfc_set(mtd, NFC_FLASH_CONFIG, CONFIG_16BIT);
691 
692 	/* Bad block options. */
693 	if (cfg.flash_bbt)
694 		chip->bbt_options = NAND_BBT_USE_FLASH | NAND_BBT_NO_OOB |
695 				    NAND_BBT_CREATE;
696 
697 	/* Single buffer only, max 256 OOB minus ECC status */
698 	if (mtd->writesize + mtd->oobsize > PAGE_2K + OOB_MAX - 8) {
699 		dev_err(nfc->dev, "Unsupported flash page size\n");
700 		err = -ENXIO;
701 		goto error;
702 	}
703 
704 	if (cfg.hardware_ecc) {
705 		if (mtd->writesize != PAGE_2K && mtd->oobsize < 64) {
706 			dev_err(nfc->dev, "Unsupported flash with hwecc\n");
707 			err = -ENXIO;
708 			goto error;
709 		}
710 
711 		if (chip->ecc.size != mtd->writesize) {
712 			dev_err(nfc->dev, "ecc size: %d\n", chip->ecc.size);
713 			dev_err(nfc->dev, "Step size needs to be page size\n");
714 			err = -ENXIO;
715 			goto error;
716 		}
717 
718 		/* Current HW ECC layouts only use 64 bytes of OOB */
719 		if (mtd->oobsize > 64)
720 			mtd->oobsize = 64;
721 
722 		/* propagate ecc.layout to mtd_info */
723 		mtd->ecclayout = chip->ecc.layout;
724 		chip->ecc.read_page = vf610_nfc_read_page;
725 		chip->ecc.write_page = vf610_nfc_write_page;
726 		chip->ecc.mode = NAND_ECC_HW;
727 
728 		chip->ecc.size = PAGE_2K;
729 		chip->ecc.layout = &vf610_nfc_ecc;
730 #if defined(CONFIG_SYS_NAND_VF610_NFC_45_ECC_BYTES)
731 		chip->ecc.strength = 24;
732 		chip->ecc.bytes = 45;
733 #elif defined(CONFIG_SYS_NAND_VF610_NFC_60_ECC_BYTES)
734 		chip->ecc.strength = 32;
735 		chip->ecc.bytes = 60;
736 #endif
737 
738 		/* Set ECC_STATUS offset */
739 		vf610_nfc_set_field(mtd, NFC_FLASH_CONFIG,
740 				    CONFIG_ECC_SRAM_ADDR_MASK,
741 				    CONFIG_ECC_SRAM_ADDR_SHIFT,
742 				    ECC_SRAM_ADDR >> 3);
743 
744 		/* Enable ECC status in SRAM */
745 		vf610_nfc_set(mtd, NFC_FLASH_CONFIG, CONFIG_ECC_SRAM_REQ_BIT);
746 	}
747 
748 	/* second phase scan */
749 	err = nand_scan_tail(mtd);
750 	if (err)
751 		return err;
752 
753 	err = nand_register(devnum, mtd);
754 	if (err)
755 		return err;
756 
757 	return 0;
758 
759 error:
760 	return err;
761 }
762 
763 void board_nand_init(void)
764 {
765 	int err = vf610_nfc_nand_init(0, (void __iomem *)CONFIG_SYS_NAND_BASE);
766 	if (err)
767 		printf("VF610 NAND init failed (err %d)\n", err);
768 }
769