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      1 // SPDX-License-Identifier: GPL-2.0+
      2 /*
      3  * (C) Copyright 2010
      4  * Vipin Kumar, ST Microelectronics, vipin.kumar (at) st.com.
      5  *
      6  * (C) Copyright 2012
      7  * Amit Virdi, ST Microelectronics, amit.virdi (at) st.com.
      8  */
      9 
     10 #include <common.h>
     11 #include <nand.h>
     12 #include <asm/io.h>
     13 #include <linux/bitops.h>
     14 #include <linux/err.h>
     15 #include <linux/mtd/nand_ecc.h>
     16 #include <linux/mtd/fsmc_nand.h>
     17 #include <asm/arch/hardware.h>
     18 
     19 static u32 fsmc_version;
     20 static struct fsmc_regs *const fsmc_regs_p = (struct fsmc_regs *)
     21 	CONFIG_SYS_FSMC_BASE;
     22 
     23 /*
     24  * ECC4 and ECC1 have 13 bytes and 3 bytes of ecc respectively for 512 bytes of
     25  * data. ECC4 can correct up to 8 bits in 512 bytes of data while ECC1 can
     26  * correct 1 bit in 512 bytes
     27  */
     28 
     29 static struct nand_ecclayout fsmc_ecc4_lp_layout = {
     30 	.eccbytes = 104,
     31 	.eccpos = {  2,   3,   4,   5,   6,   7,   8,
     32 		9,  10,  11,  12,  13,  14,
     33 		18,  19,  20,  21,  22,  23,  24,
     34 		25,  26,  27,  28,  29,  30,
     35 		34,  35,  36,  37,  38,  39,  40,
     36 		41,  42,  43,  44,  45,  46,
     37 		50,  51,  52,  53,  54,  55,  56,
     38 		57,  58,  59,  60,  61,  62,
     39 		66,  67,  68,  69,  70,  71,  72,
     40 		73,  74,  75,  76,  77,  78,
     41 		82,  83,  84,  85,  86,  87,  88,
     42 		89,  90,  91,  92,  93,  94,
     43 		98,  99, 100, 101, 102, 103, 104,
     44 		105, 106, 107, 108, 109, 110,
     45 		114, 115, 116, 117, 118, 119, 120,
     46 		121, 122, 123, 124, 125, 126
     47 	},
     48 	.oobfree = {
     49 		{.offset = 15, .length = 3},
     50 		{.offset = 31, .length = 3},
     51 		{.offset = 47, .length = 3},
     52 		{.offset = 63, .length = 3},
     53 		{.offset = 79, .length = 3},
     54 		{.offset = 95, .length = 3},
     55 		{.offset = 111, .length = 3},
     56 		{.offset = 127, .length = 1}
     57 	}
     58 };
     59 
     60 /*
     61  * ECC4 layout for NAND of pagesize 4096 bytes & OOBsize 224 bytes. 13*8 bytes
     62  * of OOB size is reserved for ECC, Byte no. 0 & 1 reserved for bad block & 118
     63  * bytes are free for use.
     64  */
     65 static struct nand_ecclayout fsmc_ecc4_224_layout = {
     66 	.eccbytes = 104,
     67 	.eccpos = {  2,   3,   4,   5,   6,   7,   8,
     68 		9,  10,  11,  12,  13,  14,
     69 		18,  19,  20,  21,  22,  23,  24,
     70 		25,  26,  27,  28,  29,  30,
     71 		34,  35,  36,  37,  38,  39,  40,
     72 		41,  42,  43,  44,  45,  46,
     73 		50,  51,  52,  53,  54,  55,  56,
     74 		57,  58,  59,  60,  61,  62,
     75 		66,  67,  68,  69,  70,  71,  72,
     76 		73,  74,  75,  76,  77,  78,
     77 		82,  83,  84,  85,  86,  87,  88,
     78 		89,  90,  91,  92,  93,  94,
     79 		98,  99, 100, 101, 102, 103, 104,
     80 		105, 106, 107, 108, 109, 110,
     81 		114, 115, 116, 117, 118, 119, 120,
     82 		121, 122, 123, 124, 125, 126
     83 	},
     84 	.oobfree = {
     85 		{.offset = 15, .length = 3},
     86 		{.offset = 31, .length = 3},
     87 		{.offset = 47, .length = 3},
     88 		{.offset = 63, .length = 3},
     89 		{.offset = 79, .length = 3},
     90 		{.offset = 95, .length = 3},
     91 		{.offset = 111, .length = 3},
     92 		{.offset = 127, .length = 97}
     93 	}
     94 };
     95 
     96 /*
     97  * ECC placement definitions in oobfree type format
     98  * There are 13 bytes of ecc for every 512 byte block and it has to be read
     99  * consecutively and immediately after the 512 byte data block for hardware to
    100  * generate the error bit offsets in 512 byte data
    101  * Managing the ecc bytes in the following way makes it easier for software to
    102  * read ecc bytes consecutive to data bytes. This way is similar to
    103  * oobfree structure maintained already in u-boot nand driver
    104  */
    105 static struct fsmc_eccplace fsmc_eccpl_lp = {
    106 	.eccplace = {
    107 		{.offset = 2, .length = 13},
    108 		{.offset = 18, .length = 13},
    109 		{.offset = 34, .length = 13},
    110 		{.offset = 50, .length = 13},
    111 		{.offset = 66, .length = 13},
    112 		{.offset = 82, .length = 13},
    113 		{.offset = 98, .length = 13},
    114 		{.offset = 114, .length = 13}
    115 	}
    116 };
    117 
    118 static struct nand_ecclayout fsmc_ecc4_sp_layout = {
    119 	.eccbytes = 13,
    120 	.eccpos = { 0,  1,  2,  3,  6,  7, 8,
    121 		9, 10, 11, 12, 13, 14
    122 	},
    123 	.oobfree = {
    124 		{.offset = 15, .length = 1},
    125 	}
    126 };
    127 
    128 static struct fsmc_eccplace fsmc_eccpl_sp = {
    129 	.eccplace = {
    130 		{.offset = 0, .length = 4},
    131 		{.offset = 6, .length = 9}
    132 	}
    133 };
    134 
    135 static struct nand_ecclayout fsmc_ecc1_layout = {
    136 	.eccbytes = 24,
    137 	.eccpos = {2, 3, 4, 18, 19, 20, 34, 35, 36, 50, 51, 52,
    138 		66, 67, 68, 82, 83, 84, 98, 99, 100, 114, 115, 116},
    139 	.oobfree = {
    140 		{.offset = 8, .length = 8},
    141 		{.offset = 24, .length = 8},
    142 		{.offset = 40, .length = 8},
    143 		{.offset = 56, .length = 8},
    144 		{.offset = 72, .length = 8},
    145 		{.offset = 88, .length = 8},
    146 		{.offset = 104, .length = 8},
    147 		{.offset = 120, .length = 8}
    148 	}
    149 };
    150 
    151 /* Count the number of 0's in buff upto a max of max_bits */
    152 static int count_written_bits(uint8_t *buff, int size, int max_bits)
    153 {
    154 	int k, written_bits = 0;
    155 
    156 	for (k = 0; k < size; k++) {
    157 		written_bits += hweight8(~buff[k]);
    158 		if (written_bits > max_bits)
    159 			break;
    160 	}
    161 
    162 	return written_bits;
    163 }
    164 
    165 static void fsmc_nand_hwcontrol(struct mtd_info *mtd, int cmd, uint ctrl)
    166 {
    167 	struct nand_chip *this = mtd_to_nand(mtd);
    168 	ulong IO_ADDR_W;
    169 
    170 	if (ctrl & NAND_CTRL_CHANGE) {
    171 		IO_ADDR_W = (ulong)this->IO_ADDR_W;
    172 
    173 		IO_ADDR_W &= ~(CONFIG_SYS_NAND_CLE | CONFIG_SYS_NAND_ALE);
    174 		if (ctrl & NAND_CLE)
    175 			IO_ADDR_W |= CONFIG_SYS_NAND_CLE;
    176 		if (ctrl & NAND_ALE)
    177 			IO_ADDR_W |= CONFIG_SYS_NAND_ALE;
    178 
    179 		if (ctrl & NAND_NCE) {
    180 			writel(readl(&fsmc_regs_p->pc) |
    181 					FSMC_ENABLE, &fsmc_regs_p->pc);
    182 		} else {
    183 			writel(readl(&fsmc_regs_p->pc) &
    184 					~FSMC_ENABLE, &fsmc_regs_p->pc);
    185 		}
    186 		this->IO_ADDR_W = (void *)IO_ADDR_W;
    187 	}
    188 
    189 	if (cmd != NAND_CMD_NONE)
    190 		writeb(cmd, this->IO_ADDR_W);
    191 }
    192 
    193 static int fsmc_bch8_correct_data(struct mtd_info *mtd, u_char *dat,
    194 		u_char *read_ecc, u_char *calc_ecc)
    195 {
    196 	/* The calculated ecc is actually the correction index in data */
    197 	u32 err_idx[8];
    198 	u32 num_err, i;
    199 	u32 ecc1, ecc2, ecc3, ecc4;
    200 
    201 	num_err = (readl(&fsmc_regs_p->sts) >> 10) & 0xF;
    202 
    203 	if (likely(num_err == 0))
    204 		return 0;
    205 
    206 	if (unlikely(num_err > 8)) {
    207 		/*
    208 		 * This is a temporary erase check. A newly erased page read
    209 		 * would result in an ecc error because the oob data is also
    210 		 * erased to FF and the calculated ecc for an FF data is not
    211 		 * FF..FF.
    212 		 * This is a workaround to skip performing correction in case
    213 		 * data is FF..FF
    214 		 *
    215 		 * Logic:
    216 		 * For every page, each bit written as 0 is counted until these
    217 		 * number of bits are greater than 8 (the maximum correction
    218 		 * capability of FSMC for each 512 + 13 bytes)
    219 		 */
    220 
    221 		int bits_ecc = count_written_bits(read_ecc, 13, 8);
    222 		int bits_data = count_written_bits(dat, 512, 8);
    223 
    224 		if ((bits_ecc + bits_data) <= 8) {
    225 			if (bits_data)
    226 				memset(dat, 0xff, 512);
    227 			return bits_data + bits_ecc;
    228 		}
    229 
    230 		return -EBADMSG;
    231 	}
    232 
    233 	ecc1 = readl(&fsmc_regs_p->ecc1);
    234 	ecc2 = readl(&fsmc_regs_p->ecc2);
    235 	ecc3 = readl(&fsmc_regs_p->ecc3);
    236 	ecc4 = readl(&fsmc_regs_p->sts);
    237 
    238 	err_idx[0] = (ecc1 >> 0) & 0x1FFF;
    239 	err_idx[1] = (ecc1 >> 13) & 0x1FFF;
    240 	err_idx[2] = (((ecc2 >> 0) & 0x7F) << 6) | ((ecc1 >> 26) & 0x3F);
    241 	err_idx[3] = (ecc2 >> 7) & 0x1FFF;
    242 	err_idx[4] = (((ecc3 >> 0) & 0x1) << 12) | ((ecc2 >> 20) & 0xFFF);
    243 	err_idx[5] = (ecc3 >> 1) & 0x1FFF;
    244 	err_idx[6] = (ecc3 >> 14) & 0x1FFF;
    245 	err_idx[7] = (((ecc4 >> 16) & 0xFF) << 5) | ((ecc3 >> 27) & 0x1F);
    246 
    247 	i = 0;
    248 	while (i < num_err) {
    249 		err_idx[i] ^= 3;
    250 
    251 		if (err_idx[i] < 512 * 8)
    252 			__change_bit(err_idx[i], dat);
    253 
    254 		i++;
    255 	}
    256 
    257 	return num_err;
    258 }
    259 
    260 static int fsmc_read_hwecc(struct mtd_info *mtd,
    261 			const u_char *data, u_char *ecc)
    262 {
    263 	u_int ecc_tmp;
    264 	int timeout = CONFIG_SYS_HZ;
    265 	ulong start;
    266 
    267 	switch (fsmc_version) {
    268 	case FSMC_VER8:
    269 		start = get_timer(0);
    270 		while (get_timer(start) < timeout) {
    271 			/*
    272 			 * Busy waiting for ecc computation
    273 			 * to finish for 512 bytes
    274 			 */
    275 			if (readl(&fsmc_regs_p->sts) & FSMC_CODE_RDY)
    276 				break;
    277 		}
    278 
    279 		ecc_tmp = readl(&fsmc_regs_p->ecc1);
    280 		ecc[0] = (u_char) (ecc_tmp >> 0);
    281 		ecc[1] = (u_char) (ecc_tmp >> 8);
    282 		ecc[2] = (u_char) (ecc_tmp >> 16);
    283 		ecc[3] = (u_char) (ecc_tmp >> 24);
    284 
    285 		ecc_tmp = readl(&fsmc_regs_p->ecc2);
    286 		ecc[4] = (u_char) (ecc_tmp >> 0);
    287 		ecc[5] = (u_char) (ecc_tmp >> 8);
    288 		ecc[6] = (u_char) (ecc_tmp >> 16);
    289 		ecc[7] = (u_char) (ecc_tmp >> 24);
    290 
    291 		ecc_tmp = readl(&fsmc_regs_p->ecc3);
    292 		ecc[8] = (u_char) (ecc_tmp >> 0);
    293 		ecc[9] = (u_char) (ecc_tmp >> 8);
    294 		ecc[10] = (u_char) (ecc_tmp >> 16);
    295 		ecc[11] = (u_char) (ecc_tmp >> 24);
    296 
    297 		ecc_tmp = readl(&fsmc_regs_p->sts);
    298 		ecc[12] = (u_char) (ecc_tmp >> 16);
    299 		break;
    300 
    301 	default:
    302 		ecc_tmp = readl(&fsmc_regs_p->ecc1);
    303 		ecc[0] = (u_char) (ecc_tmp >> 0);
    304 		ecc[1] = (u_char) (ecc_tmp >> 8);
    305 		ecc[2] = (u_char) (ecc_tmp >> 16);
    306 		break;
    307 	}
    308 
    309 	return 0;
    310 }
    311 
    312 void fsmc_enable_hwecc(struct mtd_info *mtd, int mode)
    313 {
    314 	writel(readl(&fsmc_regs_p->pc) & ~FSMC_ECCPLEN_256,
    315 			&fsmc_regs_p->pc);
    316 	writel(readl(&fsmc_regs_p->pc) & ~FSMC_ECCEN,
    317 			&fsmc_regs_p->pc);
    318 	writel(readl(&fsmc_regs_p->pc) | FSMC_ECCEN,
    319 			&fsmc_regs_p->pc);
    320 }
    321 
    322 /*
    323  * fsmc_read_page_hwecc
    324  * @mtd:	mtd info structure
    325  * @chip:	nand chip info structure
    326  * @buf:	buffer to store read data
    327  * @oob_required:	caller expects OOB data read to chip->oob_poi
    328  * @page:	page number to read
    329  *
    330  * This routine is needed for fsmc verison 8 as reading from NAND chip has to be
    331  * performed in a strict sequence as follows:
    332  * data(512 byte) -> ecc(13 byte)
    333  * After this read, fsmc hardware generates and reports error data bits(upto a
    334  * max of 8 bits)
    335  */
    336 static int fsmc_read_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
    337 				 uint8_t *buf, int oob_required, int page)
    338 {
    339 	struct fsmc_eccplace *fsmc_eccpl;
    340 	int i, j, s, stat, eccsize = chip->ecc.size;
    341 	int eccbytes = chip->ecc.bytes;
    342 	int eccsteps = chip->ecc.steps;
    343 	uint8_t *p = buf;
    344 	uint8_t *ecc_calc = chip->buffers->ecccalc;
    345 	uint8_t *ecc_code = chip->buffers->ecccode;
    346 	int off, len, group = 0;
    347 	uint8_t oob[13] __attribute__ ((aligned (2)));
    348 
    349 	/* Differentiate between small and large page ecc place definitions */
    350 	if (mtd->writesize == 512)
    351 		fsmc_eccpl = &fsmc_eccpl_sp;
    352 	else
    353 		fsmc_eccpl = &fsmc_eccpl_lp;
    354 
    355 	for (i = 0, s = 0; s < eccsteps; s++, i += eccbytes, p += eccsize) {
    356 
    357 		chip->cmdfunc(mtd, NAND_CMD_READ0, s * eccsize, page);
    358 		chip->ecc.hwctl(mtd, NAND_ECC_READ);
    359 		chip->read_buf(mtd, p, eccsize);
    360 
    361 		for (j = 0; j < eccbytes;) {
    362 			off = fsmc_eccpl->eccplace[group].offset;
    363 			len = fsmc_eccpl->eccplace[group].length;
    364 			group++;
    365 
    366 			/*
    367 			 * length is intentionally kept a higher multiple of 2
    368 			 * to read at least 13 bytes even in case of 16 bit NAND
    369 			 * devices
    370 			 */
    371 			if (chip->options & NAND_BUSWIDTH_16)
    372 				len = roundup(len, 2);
    373 			chip->cmdfunc(mtd, NAND_CMD_READOOB, off, page);
    374 			chip->read_buf(mtd, oob + j, len);
    375 			j += len;
    376 		}
    377 
    378 		memcpy(&ecc_code[i], oob, 13);
    379 		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
    380 
    381 		stat = chip->ecc.correct(mtd, p, &ecc_code[i],
    382 				&ecc_calc[i]);
    383 		if (stat < 0)
    384 			mtd->ecc_stats.failed++;
    385 		else
    386 			mtd->ecc_stats.corrected += stat;
    387 	}
    388 
    389 	return 0;
    390 }
    391 
    392 #ifndef CONFIG_SPL_BUILD
    393 /*
    394  * fsmc_nand_switch_ecc - switch the ECC operation between different engines
    395  *
    396  * @eccstrength		- the number of bits that could be corrected
    397  *			  (1 - HW, 4 - SW BCH4)
    398  */
    399 int fsmc_nand_switch_ecc(uint32_t eccstrength)
    400 {
    401 	struct nand_chip *nand;
    402 	struct mtd_info *mtd;
    403 	int err;
    404 
    405 	/*
    406 	 * This functions is only called on SPEAr600 platforms, supporting
    407 	 * 1 bit HW ECC. The BCH8 HW ECC (FSMC_VER8) from the ST-Ericsson
    408 	 * Nomadik SoC is currently supporting this fsmc_nand_switch_ecc()
    409 	 * function, as it doesn't need to switch to a different ECC layout.
    410 	 */
    411 	mtd = get_nand_dev_by_index(nand_curr_device);
    412 	nand = mtd_to_nand(mtd);
    413 
    414 	/* Setup the ecc configurations again */
    415 	if (eccstrength == 1) {
    416 		nand->ecc.mode = NAND_ECC_HW;
    417 		nand->ecc.bytes = 3;
    418 		nand->ecc.strength = 1;
    419 		nand->ecc.layout = &fsmc_ecc1_layout;
    420 		nand->ecc.calculate = fsmc_read_hwecc;
    421 		nand->ecc.correct = nand_correct_data;
    422 	} else if (eccstrength == 4) {
    423 		/*
    424 		 * .calculate .correct and .bytes will be set in
    425 		 * nand_scan_tail()
    426 		 */
    427 		nand->ecc.mode = NAND_ECC_SOFT_BCH;
    428 		nand->ecc.strength = 4;
    429 		nand->ecc.layout = NULL;
    430 	} else {
    431 		printf("Error: ECC strength %d not supported!\n", eccstrength);
    432 	}
    433 
    434 	/* Update NAND handling after ECC mode switch */
    435 	err = nand_scan_tail(mtd);
    436 
    437 	return err;
    438 }
    439 #endif /* CONFIG_SPL_BUILD */
    440 
    441 int fsmc_nand_init(struct nand_chip *nand)
    442 {
    443 	static int chip_nr;
    444 	struct mtd_info *mtd;
    445 	u32 peripid2 = readl(&fsmc_regs_p->peripid2);
    446 
    447 	fsmc_version = (peripid2 >> FSMC_REVISION_SHFT) &
    448 		FSMC_REVISION_MSK;
    449 
    450 	writel(readl(&fsmc_regs_p->ctrl) | FSMC_WP, &fsmc_regs_p->ctrl);
    451 
    452 #if defined(CONFIG_SYS_FSMC_NAND_16BIT)
    453 	writel(FSMC_DEVWID_16 | FSMC_DEVTYPE_NAND | FSMC_ENABLE | FSMC_WAITON,
    454 			&fsmc_regs_p->pc);
    455 #elif defined(CONFIG_SYS_FSMC_NAND_8BIT)
    456 	writel(FSMC_DEVWID_8 | FSMC_DEVTYPE_NAND | FSMC_ENABLE | FSMC_WAITON,
    457 			&fsmc_regs_p->pc);
    458 #else
    459 #error Please define CONFIG_SYS_FSMC_NAND_16BIT or CONFIG_SYS_FSMC_NAND_8BIT
    460 #endif
    461 	writel(readl(&fsmc_regs_p->pc) | FSMC_TCLR_1 | FSMC_TAR_1,
    462 			&fsmc_regs_p->pc);
    463 	writel(FSMC_THIZ_1 | FSMC_THOLD_4 | FSMC_TWAIT_6 | FSMC_TSET_0,
    464 			&fsmc_regs_p->comm);
    465 	writel(FSMC_THIZ_1 | FSMC_THOLD_4 | FSMC_TWAIT_6 | FSMC_TSET_0,
    466 			&fsmc_regs_p->attrib);
    467 
    468 	nand->options = 0;
    469 #if defined(CONFIG_SYS_FSMC_NAND_16BIT)
    470 	nand->options |= NAND_BUSWIDTH_16;
    471 #endif
    472 	nand->ecc.mode = NAND_ECC_HW;
    473 	nand->ecc.size = 512;
    474 	nand->ecc.calculate = fsmc_read_hwecc;
    475 	nand->ecc.hwctl = fsmc_enable_hwecc;
    476 	nand->cmd_ctrl = fsmc_nand_hwcontrol;
    477 	nand->IO_ADDR_R = nand->IO_ADDR_W =
    478 		(void  __iomem *)CONFIG_SYS_NAND_BASE;
    479 	nand->badblockbits = 7;
    480 
    481 	mtd = nand_to_mtd(nand);
    482 
    483 	switch (fsmc_version) {
    484 	case FSMC_VER8:
    485 		nand->ecc.bytes = 13;
    486 		nand->ecc.strength = 8;
    487 		nand->ecc.correct = fsmc_bch8_correct_data;
    488 		nand->ecc.read_page = fsmc_read_page_hwecc;
    489 		if (mtd->writesize == 512)
    490 			nand->ecc.layout = &fsmc_ecc4_sp_layout;
    491 		else {
    492 			if (mtd->oobsize == 224)
    493 				nand->ecc.layout = &fsmc_ecc4_224_layout;
    494 			else
    495 				nand->ecc.layout = &fsmc_ecc4_lp_layout;
    496 		}
    497 
    498 		break;
    499 	default:
    500 		nand->ecc.bytes = 3;
    501 		nand->ecc.strength = 1;
    502 		nand->ecc.layout = &fsmc_ecc1_layout;
    503 		nand->ecc.correct = nand_correct_data;
    504 		break;
    505 	}
    506 
    507 	/* Detect NAND chips */
    508 	if (nand_scan_ident(mtd, CONFIG_SYS_MAX_NAND_DEVICE, NULL))
    509 		return -ENXIO;
    510 
    511 	if (nand_scan_tail(mtd))
    512 		return -ENXIO;
    513 
    514 	if (nand_register(chip_nr++, mtd))
    515 		return -ENXIO;
    516 
    517 	return 0;
    518 }
    519