xref: /rk3399_rockchip-uboot/drivers/mtd/nand/raw/vf610_nfc.c (revision ed99f7731a5a40a9638c4b4e603f3caebef05913)
1 /*
2  * Copyright 2009-2015 Freescale Semiconductor, Inc. and others
3  *
4  * Description: MPC5125, VF610, MCF54418 and Kinetis K70 Nand driver.
5  * Ported to U-Boot by Stefan Agner
6  * Based on RFC driver posted on Kernel Mailing list by Bill Pringlemeir
7  * Jason ported to M54418TWR and MVFA5.
8  * Authors: Stefan Agner <stefan.agner@toradex.com>
9  *          Bill Pringlemeir <bpringlemeir@nbsps.com>
10  *          Shaohui Xie <b21989@freescale.com>
11  *          Jason Jin <Jason.jin@freescale.com>
12  *
13  * Based on original driver mpc5121_nfc.c.
14  *
15  * SPDX-License-Identifier:	GPL-2.0+
16  *
17  * Limitations:
18  * - Untested on MPC5125 and M54418.
19  * - DMA and pipelining not used.
20  * - 2K pages or less.
21  * - HW ECC: Only 2K page with 64+ OOB.
22  * - HW ECC: Only 24 and 32-bit error correction implemented.
23  */
24 
25 #include <common.h>
26 #include <malloc.h>
27 
28 #include <linux/mtd/mtd.h>
29 #include <linux/mtd/rawnand.h>
30 #include <linux/mtd/partitions.h>
31 
32 #include <nand.h>
33 #include <errno.h>
34 #include <asm/io.h>
35 
36 /* Register Offsets */
37 #define NFC_FLASH_CMD1			0x3F00
38 #define NFC_FLASH_CMD2			0x3F04
39 #define NFC_COL_ADDR			0x3F08
40 #define NFC_ROW_ADDR			0x3F0c
41 #define NFC_ROW_ADDR_INC		0x3F14
42 #define NFC_FLASH_STATUS1		0x3F18
43 #define NFC_FLASH_STATUS2		0x3F1c
44 #define NFC_CACHE_SWAP			0x3F28
45 #define NFC_SECTOR_SIZE			0x3F2c
46 #define NFC_FLASH_CONFIG		0x3F30
47 #define NFC_IRQ_STATUS			0x3F38
48 
49 /* Addresses for NFC MAIN RAM BUFFER areas */
50 #define NFC_MAIN_AREA(n)		((n) *  0x1000)
51 
52 #define PAGE_2K				0x0800
53 #define OOB_64				0x0040
54 #define OOB_MAX				0x0100
55 
56 /*
57  * NFC_CMD2[CODE] values. See section:
58  *  - 31.4.7 Flash Command Code Description, Vybrid manual
59  *  - 23.8.6 Flash Command Sequencer, MPC5125 manual
60  *
61  * Briefly these are bitmasks of controller cycles.
62  */
63 #define READ_PAGE_CMD_CODE		0x7EE0
64 #define READ_ONFI_PARAM_CMD_CODE	0x4860
65 #define PROGRAM_PAGE_CMD_CODE		0x7FC0
66 #define ERASE_CMD_CODE			0x4EC0
67 #define READ_ID_CMD_CODE		0x4804
68 #define RESET_CMD_CODE			0x4040
69 #define STATUS_READ_CMD_CODE		0x4068
70 
71 /* NFC ECC mode define */
72 #define ECC_BYPASS			0
73 #define ECC_45_BYTE			6
74 #define ECC_60_BYTE			7
75 
76 /*** Register Mask and bit definitions */
77 
78 /* NFC_FLASH_CMD1 Field */
79 #define CMD_BYTE2_MASK				0xFF000000
80 #define CMD_BYTE2_SHIFT				24
81 
82 /* NFC_FLASH_CM2 Field */
83 #define CMD_BYTE1_MASK				0xFF000000
84 #define CMD_BYTE1_SHIFT				24
85 #define CMD_CODE_MASK				0x00FFFF00
86 #define CMD_CODE_SHIFT				8
87 #define BUFNO_MASK				0x00000006
88 #define BUFNO_SHIFT				1
89 #define START_BIT				(1<<0)
90 
91 /* NFC_COL_ADDR Field */
92 #define COL_ADDR_MASK				0x0000FFFF
93 #define COL_ADDR_SHIFT				0
94 
95 /* NFC_ROW_ADDR Field */
96 #define ROW_ADDR_MASK				0x00FFFFFF
97 #define ROW_ADDR_SHIFT				0
98 #define ROW_ADDR_CHIP_SEL_RB_MASK		0xF0000000
99 #define ROW_ADDR_CHIP_SEL_RB_SHIFT		28
100 #define ROW_ADDR_CHIP_SEL_MASK			0x0F000000
101 #define ROW_ADDR_CHIP_SEL_SHIFT			24
102 
103 /* NFC_FLASH_STATUS2 Field */
104 #define STATUS_BYTE1_MASK			0x000000FF
105 
106 /* NFC_FLASH_CONFIG Field */
107 #define CONFIG_ECC_SRAM_ADDR_MASK		0x7FC00000
108 #define CONFIG_ECC_SRAM_ADDR_SHIFT		22
109 #define CONFIG_ECC_SRAM_REQ_BIT			(1<<21)
110 #define CONFIG_DMA_REQ_BIT			(1<<20)
111 #define CONFIG_ECC_MODE_MASK			0x000E0000
112 #define CONFIG_ECC_MODE_SHIFT			17
113 #define CONFIG_FAST_FLASH_BIT			(1<<16)
114 #define CONFIG_16BIT				(1<<7)
115 #define CONFIG_BOOT_MODE_BIT			(1<<6)
116 #define CONFIG_ADDR_AUTO_INCR_BIT		(1<<5)
117 #define CONFIG_BUFNO_AUTO_INCR_BIT		(1<<4)
118 #define CONFIG_PAGE_CNT_MASK			0xF
119 #define CONFIG_PAGE_CNT_SHIFT			0
120 
121 /* NFC_IRQ_STATUS Field */
122 #define IDLE_IRQ_BIT				(1<<29)
123 #define IDLE_EN_BIT				(1<<20)
124 #define CMD_DONE_CLEAR_BIT			(1<<18)
125 #define IDLE_CLEAR_BIT				(1<<17)
126 
127 #define NFC_TIMEOUT	(1000)
128 
129 /*
130  * ECC status - seems to consume 8 bytes (double word). The documented
131  * status byte is located in the lowest byte of the second word (which is
132  * the 4th or 7th byte depending on endianness).
133  * Calculate an offset to store the ECC status at the end of the buffer.
134  */
135 #define ECC_SRAM_ADDR		(PAGE_2K + OOB_MAX - 8)
136 
137 #define ECC_STATUS		0x4
138 #define ECC_STATUS_MASK		0x80
139 #define ECC_STATUS_ERR_COUNT	0x3F
140 
141 enum vf610_nfc_alt_buf {
142 	ALT_BUF_DATA = 0,
143 	ALT_BUF_ID = 1,
144 	ALT_BUF_STAT = 2,
145 	ALT_BUF_ONFI = 3,
146 };
147 
148 struct vf610_nfc {
149 	struct nand_chip chip;
150 	void __iomem *regs;
151 	uint buf_offset;
152 	int write_sz;
153 	/* Status and ID are in alternate locations. */
154 	enum vf610_nfc_alt_buf alt_buf;
155 };
156 
157 #define mtd_to_nfc(_mtd) nand_get_controller_data(mtd_to_nand(_mtd))
158 
159 #if defined(CONFIG_SYS_NAND_VF610_NFC_45_ECC_BYTES)
160 #define ECC_HW_MODE ECC_45_BYTE
161 
162 static struct nand_ecclayout vf610_nfc_ecc = {
163 	.eccbytes = 45,
164 	.eccpos = {19, 20, 21, 22, 23,
165 		   24, 25, 26, 27, 28, 29, 30, 31,
166 		   32, 33, 34, 35, 36, 37, 38, 39,
167 		   40, 41, 42, 43, 44, 45, 46, 47,
168 		   48, 49, 50, 51, 52, 53, 54, 55,
169 		   56, 57, 58, 59, 60, 61, 62, 63},
170 	.oobfree = {
171 		{.offset = 2,
172 		 .length = 17} }
173 };
174 #elif defined(CONFIG_SYS_NAND_VF610_NFC_60_ECC_BYTES)
175 #define ECC_HW_MODE ECC_60_BYTE
176 
177 static struct nand_ecclayout vf610_nfc_ecc = {
178 	.eccbytes = 60,
179 	.eccpos = { 4,  5,  6,  7,  8,  9, 10, 11,
180 		   12, 13, 14, 15, 16, 17, 18, 19,
181 		   20, 21, 22, 23, 24, 25, 26, 27,
182 		   28, 29, 30, 31, 32, 33, 34, 35,
183 		   36, 37, 38, 39, 40, 41, 42, 43,
184 		   44, 45, 46, 47, 48, 49, 50, 51,
185 		   52, 53, 54, 55, 56, 57, 58, 59,
186 		   60, 61, 62, 63 },
187 	.oobfree = {
188 		{.offset = 2,
189 		 .length = 2} }
190 };
191 #endif
192 
193 static inline u32 vf610_nfc_read(struct mtd_info *mtd, uint reg)
194 {
195 	struct vf610_nfc *nfc = mtd_to_nfc(mtd);
196 
197 	return readl(nfc->regs + reg);
198 }
199 
200 static inline void vf610_nfc_write(struct mtd_info *mtd, uint reg, u32 val)
201 {
202 	struct vf610_nfc *nfc = mtd_to_nfc(mtd);
203 
204 	writel(val, nfc->regs + reg);
205 }
206 
207 static inline void vf610_nfc_set(struct mtd_info *mtd, uint reg, u32 bits)
208 {
209 	vf610_nfc_write(mtd, reg, vf610_nfc_read(mtd, reg) | bits);
210 }
211 
212 static inline void vf610_nfc_clear(struct mtd_info *mtd, uint reg, u32 bits)
213 {
214 	vf610_nfc_write(mtd, reg, vf610_nfc_read(mtd, reg) & ~bits);
215 }
216 
217 static inline void vf610_nfc_set_field(struct mtd_info *mtd, u32 reg,
218 				       u32 mask, u32 shift, u32 val)
219 {
220 	vf610_nfc_write(mtd, reg,
221 			(vf610_nfc_read(mtd, reg) & (~mask)) | val << shift);
222 }
223 
224 static inline void vf610_nfc_memcpy(void *dst, const void *src, size_t n)
225 {
226 	/*
227 	 * Use this accessor for the internal SRAM buffers. On the ARM
228 	 * Freescale Vybrid SoC it's known that the driver can treat
229 	 * the SRAM buffer as if it's memory. Other platform might need
230 	 * to treat the buffers differently.
231 	 *
232 	 * For the time being, use memcpy
233 	 */
234 	memcpy(dst, src, n);
235 }
236 
237 /* Clear flags for upcoming command */
238 static inline void vf610_nfc_clear_status(void __iomem *regbase)
239 {
240 	void __iomem *reg = regbase + NFC_IRQ_STATUS;
241 	u32 tmp = __raw_readl(reg);
242 	tmp |= CMD_DONE_CLEAR_BIT | IDLE_CLEAR_BIT;
243 	__raw_writel(tmp, reg);
244 }
245 
246 /* Wait for complete operation */
247 static void vf610_nfc_done(struct mtd_info *mtd)
248 {
249 	struct vf610_nfc *nfc = mtd_to_nfc(mtd);
250 	uint start;
251 
252 	/*
253 	 * Barrier is needed after this write. This write need
254 	 * to be done before reading the next register the first
255 	 * time.
256 	 * vf610_nfc_set implicates such a barrier by using writel
257 	 * to write to the register.
258 	 */
259 	vf610_nfc_set(mtd, NFC_FLASH_CMD2, START_BIT);
260 
261 	start = get_timer(0);
262 
263 	while (!(vf610_nfc_read(mtd, NFC_IRQ_STATUS) & IDLE_IRQ_BIT)) {
264 		if (get_timer(start) > NFC_TIMEOUT) {
265 			printf("Timeout while waiting for IDLE.\n");
266 			return;
267 		}
268 	}
269 	vf610_nfc_clear_status(nfc->regs);
270 }
271 
272 static u8 vf610_nfc_get_id(struct mtd_info *mtd, int col)
273 {
274 	u32 flash_id;
275 
276 	if (col < 4) {
277 		flash_id = vf610_nfc_read(mtd, NFC_FLASH_STATUS1);
278 		flash_id >>= (3 - col) * 8;
279 	} else {
280 		flash_id = vf610_nfc_read(mtd, NFC_FLASH_STATUS2);
281 		flash_id >>= 24;
282 	}
283 
284 	return flash_id & 0xff;
285 }
286 
287 static u8 vf610_nfc_get_status(struct mtd_info *mtd)
288 {
289 	return vf610_nfc_read(mtd, NFC_FLASH_STATUS2) & STATUS_BYTE1_MASK;
290 }
291 
292 /* Single command */
293 static void vf610_nfc_send_command(void __iomem *regbase, u32 cmd_byte1,
294 				   u32 cmd_code)
295 {
296 	void __iomem *reg = regbase + NFC_FLASH_CMD2;
297 	u32 tmp;
298 	vf610_nfc_clear_status(regbase);
299 
300 	tmp = __raw_readl(reg);
301 	tmp &= ~(CMD_BYTE1_MASK | CMD_CODE_MASK | BUFNO_MASK);
302 	tmp |= cmd_byte1 << CMD_BYTE1_SHIFT;
303 	tmp |= cmd_code << CMD_CODE_SHIFT;
304 	__raw_writel(tmp, reg);
305 }
306 
307 /* Two commands */
308 static void vf610_nfc_send_commands(void __iomem *regbase, u32 cmd_byte1,
309 			      u32 cmd_byte2, u32 cmd_code)
310 {
311 	void __iomem *reg = regbase + NFC_FLASH_CMD1;
312 	u32 tmp;
313 	vf610_nfc_send_command(regbase, cmd_byte1, cmd_code);
314 
315 	tmp = __raw_readl(reg);
316 	tmp &= ~CMD_BYTE2_MASK;
317 	tmp |= cmd_byte2 << CMD_BYTE2_SHIFT;
318 	__raw_writel(tmp, reg);
319 }
320 
321 static void vf610_nfc_addr_cycle(struct mtd_info *mtd, int column, int page)
322 {
323 	if (column != -1) {
324 		struct vf610_nfc *nfc = mtd_to_nfc(mtd);
325 		if (nfc->chip.options & NAND_BUSWIDTH_16)
326 			column = column / 2;
327 		vf610_nfc_set_field(mtd, NFC_COL_ADDR, COL_ADDR_MASK,
328 				    COL_ADDR_SHIFT, column);
329 	}
330 	if (page != -1)
331 		vf610_nfc_set_field(mtd, NFC_ROW_ADDR, ROW_ADDR_MASK,
332 				    ROW_ADDR_SHIFT, page);
333 }
334 
335 static inline void vf610_nfc_ecc_mode(struct mtd_info *mtd, int ecc_mode)
336 {
337 	vf610_nfc_set_field(mtd, NFC_FLASH_CONFIG,
338 			    CONFIG_ECC_MODE_MASK,
339 			    CONFIG_ECC_MODE_SHIFT, ecc_mode);
340 }
341 
342 static inline void vf610_nfc_transfer_size(void __iomem *regbase, int size)
343 {
344 	__raw_writel(size, regbase + NFC_SECTOR_SIZE);
345 }
346 
347 /* Send command to NAND chip */
348 static void vf610_nfc_command(struct mtd_info *mtd, unsigned command,
349 			      int column, int page)
350 {
351 	struct vf610_nfc *nfc = mtd_to_nfc(mtd);
352 	int trfr_sz = nfc->chip.options & NAND_BUSWIDTH_16 ? 1 : 0;
353 
354 	nfc->buf_offset = max(column, 0);
355 	nfc->alt_buf = ALT_BUF_DATA;
356 
357 	switch (command) {
358 	case NAND_CMD_SEQIN:
359 		/* Use valid column/page from preread... */
360 		vf610_nfc_addr_cycle(mtd, column, page);
361 		nfc->buf_offset = 0;
362 
363 		/*
364 		 * SEQIN => data => PAGEPROG sequence is done by the controller
365 		 * hence we do not need to issue the command here...
366 		 */
367 		return;
368 	case NAND_CMD_PAGEPROG:
369 		trfr_sz += nfc->write_sz;
370 		vf610_nfc_ecc_mode(mtd, ECC_HW_MODE);
371 		vf610_nfc_transfer_size(nfc->regs, trfr_sz);
372 		vf610_nfc_send_commands(nfc->regs, NAND_CMD_SEQIN,
373 					command, PROGRAM_PAGE_CMD_CODE);
374 		break;
375 
376 	case NAND_CMD_RESET:
377 		vf610_nfc_transfer_size(nfc->regs, 0);
378 		vf610_nfc_send_command(nfc->regs, command, RESET_CMD_CODE);
379 		break;
380 
381 	case NAND_CMD_READOOB:
382 		trfr_sz += mtd->oobsize;
383 		column = mtd->writesize;
384 		vf610_nfc_transfer_size(nfc->regs, trfr_sz);
385 		vf610_nfc_send_commands(nfc->regs, NAND_CMD_READ0,
386 					NAND_CMD_READSTART, READ_PAGE_CMD_CODE);
387 		vf610_nfc_addr_cycle(mtd, column, page);
388 		vf610_nfc_ecc_mode(mtd, ECC_BYPASS);
389 		break;
390 
391 	case NAND_CMD_READ0:
392 		trfr_sz += mtd->writesize + mtd->oobsize;
393 		vf610_nfc_transfer_size(nfc->regs, trfr_sz);
394 		vf610_nfc_ecc_mode(mtd, ECC_HW_MODE);
395 		vf610_nfc_send_commands(nfc->regs, NAND_CMD_READ0,
396 					NAND_CMD_READSTART, READ_PAGE_CMD_CODE);
397 		vf610_nfc_addr_cycle(mtd, column, page);
398 		break;
399 
400 	case NAND_CMD_PARAM:
401 		nfc->alt_buf = ALT_BUF_ONFI;
402 		trfr_sz = 3 * sizeof(struct nand_onfi_params);
403 		vf610_nfc_transfer_size(nfc->regs, trfr_sz);
404 		vf610_nfc_send_command(nfc->regs, NAND_CMD_PARAM,
405 				       READ_ONFI_PARAM_CMD_CODE);
406 		vf610_nfc_set_field(mtd, NFC_ROW_ADDR, ROW_ADDR_MASK,
407 				    ROW_ADDR_SHIFT, column);
408 		vf610_nfc_ecc_mode(mtd, ECC_BYPASS);
409 		break;
410 
411 	case NAND_CMD_ERASE1:
412 		vf610_nfc_transfer_size(nfc->regs, 0);
413 		vf610_nfc_send_commands(nfc->regs, command,
414 					NAND_CMD_ERASE2, ERASE_CMD_CODE);
415 		vf610_nfc_addr_cycle(mtd, column, page);
416 		break;
417 
418 	case NAND_CMD_READID:
419 		nfc->alt_buf = ALT_BUF_ID;
420 		nfc->buf_offset = 0;
421 		vf610_nfc_transfer_size(nfc->regs, 0);
422 		vf610_nfc_send_command(nfc->regs, command, READ_ID_CMD_CODE);
423 		vf610_nfc_set_field(mtd, NFC_ROW_ADDR, ROW_ADDR_MASK,
424 				    ROW_ADDR_SHIFT, column);
425 		break;
426 
427 	case NAND_CMD_STATUS:
428 		nfc->alt_buf = ALT_BUF_STAT;
429 		vf610_nfc_transfer_size(nfc->regs, 0);
430 		vf610_nfc_send_command(nfc->regs, command, STATUS_READ_CMD_CODE);
431 		break;
432 	default:
433 		return;
434 	}
435 
436 	vf610_nfc_done(mtd);
437 
438 	nfc->write_sz = 0;
439 }
440 
441 /* Read data from NFC buffers */
442 static void vf610_nfc_read_buf(struct mtd_info *mtd, u_char *buf, int len)
443 {
444 	struct vf610_nfc *nfc = mtd_to_nfc(mtd);
445 	uint c = nfc->buf_offset;
446 
447 	/* Alternate buffers are only supported through read_byte */
448 	if (nfc->alt_buf)
449 		return;
450 
451 	vf610_nfc_memcpy(buf, nfc->regs + NFC_MAIN_AREA(0) + c, len);
452 
453 	nfc->buf_offset += len;
454 }
455 
456 /* Write data to NFC buffers */
457 static void vf610_nfc_write_buf(struct mtd_info *mtd, const uint8_t *buf,
458 				int len)
459 {
460 	struct vf610_nfc *nfc = mtd_to_nfc(mtd);
461 	uint c = nfc->buf_offset;
462 	uint l;
463 
464 	l = min_t(uint, len, mtd->writesize + mtd->oobsize - c);
465 	vf610_nfc_memcpy(nfc->regs + NFC_MAIN_AREA(0) + c, buf, l);
466 
467 	nfc->write_sz += l;
468 	nfc->buf_offset += l;
469 }
470 
471 /* Read byte from NFC buffers */
472 static uint8_t vf610_nfc_read_byte(struct mtd_info *mtd)
473 {
474 	struct vf610_nfc *nfc = mtd_to_nfc(mtd);
475 	u8 tmp;
476 	uint c = nfc->buf_offset;
477 
478 	switch (nfc->alt_buf) {
479 	case ALT_BUF_ID:
480 		tmp = vf610_nfc_get_id(mtd, c);
481 		break;
482 	case ALT_BUF_STAT:
483 		tmp = vf610_nfc_get_status(mtd);
484 		break;
485 #ifdef __LITTLE_ENDIAN
486 	case ALT_BUF_ONFI:
487 		/* Reverse byte since the controller uses big endianness */
488 		c = nfc->buf_offset ^ 0x3;
489 		/* fall-through */
490 #endif
491 	default:
492 		tmp = *((u8 *)(nfc->regs + NFC_MAIN_AREA(0) + c));
493 		break;
494 	}
495 	nfc->buf_offset++;
496 	return tmp;
497 }
498 
499 /* Read word from NFC buffers */
500 static u16 vf610_nfc_read_word(struct mtd_info *mtd)
501 {
502 	u16 tmp;
503 
504 	vf610_nfc_read_buf(mtd, (u_char *)&tmp, sizeof(tmp));
505 	return tmp;
506 }
507 
508 /* If not provided, upper layers apply a fixed delay. */
509 static int vf610_nfc_dev_ready(struct mtd_info *mtd)
510 {
511 	/* NFC handles R/B internally; always ready.  */
512 	return 1;
513 }
514 
515 /*
516  * This function supports Vybrid only (MPC5125 would have full RB and four CS)
517  */
518 static void vf610_nfc_select_chip(struct mtd_info *mtd, int chip)
519 {
520 #ifdef CONFIG_VF610
521 	u32 tmp = vf610_nfc_read(mtd, NFC_ROW_ADDR);
522 	tmp &= ~(ROW_ADDR_CHIP_SEL_RB_MASK | ROW_ADDR_CHIP_SEL_MASK);
523 
524 	if (chip >= 0) {
525 		tmp |= 1 << ROW_ADDR_CHIP_SEL_RB_SHIFT;
526 		tmp |= (1 << chip) << ROW_ADDR_CHIP_SEL_SHIFT;
527 	}
528 
529 	vf610_nfc_write(mtd, NFC_ROW_ADDR, tmp);
530 #endif
531 }
532 
533 /* Count the number of 0's in buff upto max_bits */
534 static inline int count_written_bits(uint8_t *buff, int size, int max_bits)
535 {
536 	uint32_t *buff32 = (uint32_t *)buff;
537 	int k, written_bits = 0;
538 
539 	for (k = 0; k < (size / 4); k++) {
540 		written_bits += hweight32(~buff32[k]);
541 		if (written_bits > max_bits)
542 			break;
543 	}
544 
545 	return written_bits;
546 }
547 
548 static inline int vf610_nfc_correct_data(struct mtd_info *mtd, uint8_t *dat,
549 					 uint8_t *oob, int page)
550 {
551 	struct vf610_nfc *nfc = mtd_to_nfc(mtd);
552 	u32 ecc_status_off = NFC_MAIN_AREA(0) + ECC_SRAM_ADDR + ECC_STATUS;
553 	u8 ecc_status;
554 	u8 ecc_count;
555 	int flips;
556 	int flips_threshold = nfc->chip.ecc.strength / 2;
557 
558 	ecc_status = vf610_nfc_read(mtd, ecc_status_off) & 0xff;
559 	ecc_count = ecc_status & ECC_STATUS_ERR_COUNT;
560 
561 	if (!(ecc_status & ECC_STATUS_MASK))
562 		return ecc_count;
563 
564 	/* Read OOB without ECC unit enabled */
565 	vf610_nfc_command(mtd, NAND_CMD_READOOB, 0, page);
566 	vf610_nfc_read_buf(mtd, oob, mtd->oobsize);
567 
568 	/*
569 	 * On an erased page, bit count (including OOB) should be zero or
570 	 * at least less then half of the ECC strength.
571 	 */
572 	flips = count_written_bits(dat, nfc->chip.ecc.size, flips_threshold);
573 	flips += count_written_bits(oob, mtd->oobsize, flips_threshold);
574 
575 	if (unlikely(flips > flips_threshold))
576 		return -EINVAL;
577 
578 	/* Erased page. */
579 	memset(dat, 0xff, nfc->chip.ecc.size);
580 	memset(oob, 0xff, mtd->oobsize);
581 	return flips;
582 }
583 
584 static int vf610_nfc_read_page(struct mtd_info *mtd, struct nand_chip *chip,
585 				uint8_t *buf, int oob_required, int page)
586 {
587 	int eccsize = chip->ecc.size;
588 	int stat;
589 
590 	vf610_nfc_read_buf(mtd, buf, eccsize);
591 	if (oob_required)
592 		vf610_nfc_read_buf(mtd, chip->oob_poi, mtd->oobsize);
593 
594 	stat = vf610_nfc_correct_data(mtd, buf, chip->oob_poi, page);
595 
596 	if (stat < 0) {
597 		mtd->ecc_stats.failed++;
598 		return 0;
599 	} else {
600 		mtd->ecc_stats.corrected += stat;
601 		return stat;
602 	}
603 }
604 
605 /*
606  * ECC will be calculated automatically
607  */
608 static int vf610_nfc_write_page(struct mtd_info *mtd, struct nand_chip *chip,
609 			       const uint8_t *buf, int oob_required, int page)
610 {
611 	struct vf610_nfc *nfc = mtd_to_nfc(mtd);
612 
613 	vf610_nfc_write_buf(mtd, buf, mtd->writesize);
614 	if (oob_required)
615 		vf610_nfc_write_buf(mtd, chip->oob_poi, mtd->oobsize);
616 
617 	/* Always write whole page including OOB due to HW ECC */
618 	nfc->write_sz = mtd->writesize + mtd->oobsize;
619 
620 	return 0;
621 }
622 
623 struct vf610_nfc_config {
624 	int hardware_ecc;
625 	int width;
626 	int flash_bbt;
627 };
628 
629 static int vf610_nfc_nand_init(int devnum, void __iomem *addr)
630 {
631 	struct mtd_info *mtd;
632 	struct nand_chip *chip;
633 	struct vf610_nfc *nfc;
634 	int err = 0;
635 	struct vf610_nfc_config cfg = {
636 		.hardware_ecc = 1,
637 #ifdef CONFIG_SYS_NAND_BUSWIDTH_16BIT
638 		.width = 16,
639 #else
640 		.width = 8,
641 #endif
642 		.flash_bbt = 1,
643 	};
644 
645 	nfc = malloc(sizeof(*nfc));
646 	if (!nfc) {
647 		printf(KERN_ERR "%s: Memory exhausted!\n", __func__);
648 		return -ENOMEM;
649 	}
650 
651 	chip = &nfc->chip;
652 	nfc->regs = addr;
653 
654 	mtd = nand_to_mtd(chip);
655 	nand_set_controller_data(chip, nfc);
656 
657 	if (cfg.width == 16)
658 		chip->options |= NAND_BUSWIDTH_16;
659 
660 	chip->dev_ready = vf610_nfc_dev_ready;
661 	chip->cmdfunc = vf610_nfc_command;
662 	chip->read_byte = vf610_nfc_read_byte;
663 	chip->read_word = vf610_nfc_read_word;
664 	chip->read_buf = vf610_nfc_read_buf;
665 	chip->write_buf = vf610_nfc_write_buf;
666 	chip->select_chip = vf610_nfc_select_chip;
667 
668 	chip->options |= NAND_NO_SUBPAGE_WRITE;
669 
670 	chip->ecc.size = PAGE_2K;
671 
672 	/* Set configuration register. */
673 	vf610_nfc_clear(mtd, NFC_FLASH_CONFIG, CONFIG_16BIT);
674 	vf610_nfc_clear(mtd, NFC_FLASH_CONFIG, CONFIG_ADDR_AUTO_INCR_BIT);
675 	vf610_nfc_clear(mtd, NFC_FLASH_CONFIG, CONFIG_BUFNO_AUTO_INCR_BIT);
676 	vf610_nfc_clear(mtd, NFC_FLASH_CONFIG, CONFIG_BOOT_MODE_BIT);
677 	vf610_nfc_clear(mtd, NFC_FLASH_CONFIG, CONFIG_DMA_REQ_BIT);
678 	vf610_nfc_set(mtd, NFC_FLASH_CONFIG, CONFIG_FAST_FLASH_BIT);
679 
680 	/* Disable virtual pages, only one elementary transfer unit */
681 	vf610_nfc_set_field(mtd, NFC_FLASH_CONFIG, CONFIG_PAGE_CNT_MASK,
682 			    CONFIG_PAGE_CNT_SHIFT, 1);
683 
684 	/* first scan to find the device and get the page size */
685 	if (nand_scan_ident(mtd, CONFIG_SYS_MAX_NAND_DEVICE, NULL)) {
686 		err = -ENXIO;
687 		goto error;
688 	}
689 
690 	if (cfg.width == 16)
691 		vf610_nfc_set(mtd, NFC_FLASH_CONFIG, CONFIG_16BIT);
692 
693 	/* Bad block options. */
694 	if (cfg.flash_bbt)
695 		chip->bbt_options = NAND_BBT_USE_FLASH | NAND_BBT_NO_OOB |
696 				    NAND_BBT_CREATE;
697 
698 	/* Single buffer only, max 256 OOB minus ECC status */
699 	if (mtd->writesize + mtd->oobsize > PAGE_2K + OOB_MAX - 8) {
700 		dev_err(nfc->dev, "Unsupported flash page size\n");
701 		err = -ENXIO;
702 		goto error;
703 	}
704 
705 	if (cfg.hardware_ecc) {
706 		if (mtd->writesize != PAGE_2K && mtd->oobsize < 64) {
707 			dev_err(nfc->dev, "Unsupported flash with hwecc\n");
708 			err = -ENXIO;
709 			goto error;
710 		}
711 
712 		if (chip->ecc.size != mtd->writesize) {
713 			dev_err(nfc->dev, "ecc size: %d\n", chip->ecc.size);
714 			dev_err(nfc->dev, "Step size needs to be page size\n");
715 			err = -ENXIO;
716 			goto error;
717 		}
718 
719 		/* Current HW ECC layouts only use 64 bytes of OOB */
720 		if (mtd->oobsize > 64)
721 			mtd->oobsize = 64;
722 
723 		/* propagate ecc.layout to mtd_info */
724 		mtd->ecclayout = chip->ecc.layout;
725 		chip->ecc.read_page = vf610_nfc_read_page;
726 		chip->ecc.write_page = vf610_nfc_write_page;
727 		chip->ecc.mode = NAND_ECC_HW;
728 
729 		chip->ecc.size = PAGE_2K;
730 		chip->ecc.layout = &vf610_nfc_ecc;
731 #if defined(CONFIG_SYS_NAND_VF610_NFC_45_ECC_BYTES)
732 		chip->ecc.strength = 24;
733 		chip->ecc.bytes = 45;
734 #elif defined(CONFIG_SYS_NAND_VF610_NFC_60_ECC_BYTES)
735 		chip->ecc.strength = 32;
736 		chip->ecc.bytes = 60;
737 #endif
738 
739 		/* Set ECC_STATUS offset */
740 		vf610_nfc_set_field(mtd, NFC_FLASH_CONFIG,
741 				    CONFIG_ECC_SRAM_ADDR_MASK,
742 				    CONFIG_ECC_SRAM_ADDR_SHIFT,
743 				    ECC_SRAM_ADDR >> 3);
744 
745 		/* Enable ECC status in SRAM */
746 		vf610_nfc_set(mtd, NFC_FLASH_CONFIG, CONFIG_ECC_SRAM_REQ_BIT);
747 	}
748 
749 	/* second phase scan */
750 	err = nand_scan_tail(mtd);
751 	if (err)
752 		return err;
753 
754 	err = nand_register(devnum, mtd);
755 	if (err)
756 		return err;
757 
758 	return 0;
759 
760 error:
761 	return err;
762 }
763 
764 void board_nand_init(void)
765 {
766 	int err = vf610_nfc_nand_init(0, (void __iomem *)CONFIG_SYS_NAND_BASE);
767 	if (err)
768 		printf("VF610 NAND init failed (err %d)\n", err);
769 }
770