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      1 // SPDX-License-Identifier: GPL-2.0+
      2 /*
      3  * Copyright (C) 2015
      4  * Cristian Birsan <cristian.birsan (at) microchip.com>
      5  * Purna Chandra Mandal <purna.mandal (at) microchip.com>
      6  */
      7 
      8 #include <common.h>
      9 #include <dm.h>
     10 #include <fdt_support.h>
     11 #include <flash.h>
     12 #include <mach/pic32.h>
     13 #include <wait_bit.h>
     14 
     15 DECLARE_GLOBAL_DATA_PTR;
     16 
     17 /* NVM Controller registers */
     18 struct pic32_reg_nvm {
     19 	struct pic32_reg_atomic ctrl;
     20 	struct pic32_reg_atomic key;
     21 	struct pic32_reg_atomic addr;
     22 	struct pic32_reg_atomic data;
     23 };
     24 
     25 /* NVM operations */
     26 #define NVMOP_NOP		0
     27 #define NVMOP_WORD_WRITE	1
     28 #define NVMOP_PAGE_ERASE	4
     29 
     30 /* NVM control bits */
     31 #define NVM_WR			BIT(15)
     32 #define NVM_WREN		BIT(14)
     33 #define NVM_WRERR		BIT(13)
     34 #define NVM_LVDERR		BIT(12)
     35 
     36 /* NVM programming unlock register */
     37 #define LOCK_KEY		0x0
     38 #define UNLOCK_KEY1		0xaa996655
     39 #define UNLOCK_KEY2		0x556699aa
     40 
     41 /*
     42  * PIC32 flash banks consist of number of pages, each page
     43  * into number of rows and rows into number of words.
     44  * Here we will maintain page information instead of sector.
     45  */
     46 flash_info_t flash_info[CONFIG_SYS_MAX_FLASH_BANKS];
     47 static struct pic32_reg_nvm *nvm_regs_p;
     48 
     49 static inline void flash_initiate_operation(u32 nvmop)
     50 {
     51 	/* set operation */
     52 	writel(nvmop, &nvm_regs_p->ctrl.raw);
     53 
     54 	/* enable flash write */
     55 	writel(NVM_WREN, &nvm_regs_p->ctrl.set);
     56 
     57 	/* unlock sequence */
     58 	writel(LOCK_KEY, &nvm_regs_p->key.raw);
     59 	writel(UNLOCK_KEY1, &nvm_regs_p->key.raw);
     60 	writel(UNLOCK_KEY2, &nvm_regs_p->key.raw);
     61 
     62 	/* initiate operation */
     63 	writel(NVM_WR, &nvm_regs_p->ctrl.set);
     64 }
     65 
     66 static int flash_wait_till_busy(const char *func, ulong timeout)
     67 {
     68 	int ret = wait_for_bit_le32(&nvm_regs_p->ctrl.raw,
     69 				    NVM_WR, false, timeout, false);
     70 
     71 	return ret ? ERR_TIMEOUT : ERR_OK;
     72 }
     73 
     74 static inline int flash_complete_operation(void)
     75 {
     76 	u32 tmp;
     77 
     78 	tmp = readl(&nvm_regs_p->ctrl.raw);
     79 	if (tmp & NVM_WRERR) {
     80 		printf("Error in Block Erase - Lock Bit may be set!\n");
     81 		flash_initiate_operation(NVMOP_NOP);
     82 		return ERR_PROTECTED;
     83 	}
     84 
     85 	if (tmp & NVM_LVDERR) {
     86 		printf("Error in Block Erase - low-vol detected!\n");
     87 		flash_initiate_operation(NVMOP_NOP);
     88 		return ERR_NOT_ERASED;
     89 	}
     90 
     91 	/* disable flash write or erase operation */
     92 	writel(NVM_WREN, &nvm_regs_p->ctrl.clr);
     93 
     94 	return ERR_OK;
     95 }
     96 
     97 /*
     98  * Erase flash sectors, returns:
     99  * ERR_OK - OK
    100  * ERR_INVAL - invalid sector arguments
    101  * ERR_TIMEOUT - write timeout
    102  * ERR_NOT_ERASED - Flash not erased
    103  * ERR_UNKNOWN_FLASH_VENDOR - incorrect flash
    104  */
    105 int flash_erase(flash_info_t *info, int s_first, int s_last)
    106 {
    107 	ulong sect_start, sect_end, flags;
    108 	int prot, sect;
    109 	int rc;
    110 
    111 	if ((info->flash_id & FLASH_VENDMASK) != FLASH_MAN_MCHP) {
    112 		printf("Can't erase unknown flash type %08lx - aborted\n",
    113 		       info->flash_id);
    114 		return ERR_UNKNOWN_FLASH_VENDOR;
    115 	}
    116 
    117 	if ((s_first < 0) || (s_first > s_last)) {
    118 		printf("- no sectors to erase\n");
    119 		return ERR_INVAL;
    120 	}
    121 
    122 	prot = 0;
    123 	for (sect = s_first; sect <= s_last; ++sect) {
    124 		if (info->protect[sect])
    125 			prot++;
    126 	}
    127 
    128 	if (prot)
    129 		printf("- Warning: %d protected sectors will not be erased!\n",
    130 		       prot);
    131 	else
    132 		printf("\n");
    133 
    134 	/* erase on unprotected sectors */
    135 	for (sect = s_first; sect <= s_last; sect++) {
    136 		if (info->protect[sect])
    137 			continue;
    138 
    139 		/* disable interrupts */
    140 		flags = disable_interrupts();
    141 
    142 		/* write destination page address (physical) */
    143 		sect_start = CPHYSADDR(info->start[sect]);
    144 		writel(sect_start, &nvm_regs_p->addr.raw);
    145 
    146 		/* page erase */
    147 		flash_initiate_operation(NVMOP_PAGE_ERASE);
    148 
    149 		/* wait */
    150 		rc = flash_wait_till_busy(__func__,
    151 					  CONFIG_SYS_FLASH_ERASE_TOUT);
    152 
    153 		/* re-enable interrupts if necessary */
    154 		if (flags)
    155 			enable_interrupts();
    156 
    157 		if (rc != ERR_OK)
    158 			return rc;
    159 
    160 		rc = flash_complete_operation();
    161 		if (rc != ERR_OK)
    162 			return rc;
    163 
    164 		/*
    165 		 * flash content is updated but cache might contain stale
    166 		 * data, so invalidate dcache.
    167 		 */
    168 		sect_end = info->start[sect] + info->size / info->sector_count;
    169 		invalidate_dcache_range(info->start[sect], sect_end);
    170 	}
    171 
    172 	printf(" done\n");
    173 	return ERR_OK;
    174 }
    175 
    176 int page_erase(flash_info_t *info, int sect)
    177 {
    178 	return 0;
    179 }
    180 
    181 /* Write a word to flash */
    182 static int write_word(flash_info_t *info, ulong dest, ulong word)
    183 {
    184 	ulong flags;
    185 	int rc;
    186 
    187 	/* read flash to check if it is sufficiently erased */
    188 	if ((readl((void __iomem *)dest) & word) != word) {
    189 		printf("Error, Flash not erased!\n");
    190 		return ERR_NOT_ERASED;
    191 	}
    192 
    193 	/* disable interrupts */
    194 	flags = disable_interrupts();
    195 
    196 	/* update destination page address (physical) */
    197 	writel(CPHYSADDR(dest), &nvm_regs_p->addr.raw);
    198 	writel(word, &nvm_regs_p->data.raw);
    199 
    200 	/* word write */
    201 	flash_initiate_operation(NVMOP_WORD_WRITE);
    202 
    203 	/* wait for operation to complete */
    204 	rc = flash_wait_till_busy(__func__, CONFIG_SYS_FLASH_WRITE_TOUT);
    205 
    206 	/* re-enable interrupts if necessary */
    207 	if (flags)
    208 		enable_interrupts();
    209 
    210 	if (rc != ERR_OK)
    211 		return rc;
    212 
    213 	return flash_complete_operation();
    214 }
    215 
    216 /*
    217  * Copy memory to flash, returns:
    218  * ERR_OK - OK
    219  * ERR_TIMEOUT - write timeout
    220  * ERR_NOT_ERASED - Flash not erased
    221  */
    222 int write_buff(flash_info_t *info, uchar *src, ulong addr, ulong cnt)
    223 {
    224 	ulong dst, tmp_le, len = cnt;
    225 	int i, l, rc;
    226 	uchar *cp;
    227 
    228 	/* get lower word aligned address */
    229 	dst = (addr & ~3);
    230 
    231 	/* handle unaligned start bytes */
    232 	l = addr - dst;
    233 	if (l != 0) {
    234 		tmp_le = 0;
    235 		for (i = 0, cp = (uchar *)dst; i < l; ++i, ++cp)
    236 			tmp_le |= *cp << (i * 8);
    237 
    238 		for (; (i < 4) && (cnt > 0); ++i, ++src, --cnt, ++cp)
    239 			tmp_le |= *src << (i * 8);
    240 
    241 		for (; (cnt == 0) && (i < 4); ++i, ++cp)
    242 			tmp_le |= *cp << (i * 8);
    243 
    244 		rc = write_word(info, dst, tmp_le);
    245 		if (rc)
    246 			goto out;
    247 
    248 		dst += 4;
    249 	}
    250 
    251 	/* handle word aligned part */
    252 	while (cnt >= 4) {
    253 		tmp_le = src[0] | src[1] << 8 | src[2] << 16 | src[3] << 24;
    254 		rc = write_word(info, dst, tmp_le);
    255 		if (rc)
    256 			goto out;
    257 		src += 4;
    258 		dst += 4;
    259 		cnt -= 4;
    260 	}
    261 
    262 	if (cnt == 0) {
    263 		rc = ERR_OK;
    264 		goto out;
    265 	}
    266 
    267 	/* handle unaligned tail bytes */
    268 	tmp_le = 0;
    269 	for (i = 0, cp = (uchar *)dst; (i < 4) && (cnt > 0); ++i, ++cp) {
    270 		tmp_le |= *src++ << (i * 8);
    271 		--cnt;
    272 	}
    273 
    274 	for (; i < 4; ++i, ++cp)
    275 		tmp_le |= *cp << (i * 8);
    276 
    277 	rc = write_word(info, dst, tmp_le);
    278 out:
    279 	/*
    280 	 * flash content updated by nvm controller but CPU cache might
    281 	 * have stale data, so invalidate dcache.
    282 	 */
    283 	invalidate_dcache_range(addr, addr + len);
    284 
    285 	printf(" done\n");
    286 	return rc;
    287 }
    288 
    289 void flash_print_info(flash_info_t *info)
    290 {
    291 	int i;
    292 
    293 	if (info->flash_id == FLASH_UNKNOWN) {
    294 		printf("missing or unknown FLASH type\n");
    295 		return;
    296 	}
    297 
    298 	switch (info->flash_id & FLASH_VENDMASK) {
    299 	case FLASH_MAN_MCHP:
    300 		printf("Microchip Technology ");
    301 		break;
    302 	default:
    303 		printf("Unknown Vendor ");
    304 		break;
    305 	}
    306 
    307 	switch (info->flash_id & FLASH_TYPEMASK) {
    308 	case FLASH_MCHP100T:
    309 		printf("Internal (8 Mbit, 64 x 16k)\n");
    310 		break;
    311 	default:
    312 		printf("Unknown Chip Type\n");
    313 		break;
    314 	}
    315 
    316 	printf("  Size: %ld MB in %d Sectors\n",
    317 	       info->size >> 20, info->sector_count);
    318 
    319 	printf("  Sector Start Addresses:");
    320 	for (i = 0; i < info->sector_count; ++i) {
    321 		if ((i % 5) == 0)
    322 			printf("\n   ");
    323 
    324 		printf(" %08lX%s", info->start[i],
    325 		       info->protect[i] ? " (RO)" : "     ");
    326 	}
    327 	printf("\n");
    328 }
    329 
    330 unsigned long flash_init(void)
    331 {
    332 	unsigned long size = 0;
    333 	struct udevice *dev;
    334 	int bank;
    335 
    336 	/* probe every MTD device */
    337 	for (uclass_first_device(UCLASS_MTD, &dev); dev;
    338 	     uclass_next_device(&dev)) {
    339 		/* nop */
    340 	}
    341 
    342 	/* calc total flash size */
    343 	for (bank = 0; bank < CONFIG_SYS_MAX_FLASH_BANKS; ++bank)
    344 		size += flash_info[bank].size;
    345 
    346 	return size;
    347 }
    348 
    349 static void pic32_flash_bank_init(flash_info_t *info,
    350 				  ulong base, ulong size)
    351 {
    352 	ulong sect_size;
    353 	int sect;
    354 
    355 	/* device & manufacturer code */
    356 	info->flash_id = FLASH_MAN_MCHP | FLASH_MCHP100T;
    357 	info->sector_count = CONFIG_SYS_MAX_FLASH_SECT;
    358 	info->size = size;
    359 
    360 	/* update sector (i.e page) info */
    361 	sect_size = info->size / info->sector_count;
    362 	for (sect = 0; sect < info->sector_count; sect++) {
    363 		info->start[sect] = base;
    364 		/* protect each sector by default */
    365 		info->protect[sect] = 1;
    366 		base += sect_size;
    367 	}
    368 }
    369 
    370 static int pic32_flash_probe(struct udevice *dev)
    371 {
    372 	void *blob = (void *)gd->fdt_blob;
    373 	int node = dev_of_offset(dev);
    374 	const char *list, *end;
    375 	const fdt32_t *cell;
    376 	unsigned long addr, size;
    377 	int parent, addrc, sizec;
    378 	flash_info_t *info;
    379 	int len, idx;
    380 
    381 	/*
    382 	 * decode regs. there are multiple reg tuples, and they need to
    383 	 * match with reg-names.
    384 	 */
    385 	parent = fdt_parent_offset(blob, node);
    386 	fdt_support_default_count_cells(blob, parent, &addrc, &sizec);
    387 	list = fdt_getprop(blob, node, "reg-names", &len);
    388 	if (!list)
    389 		return -ENOENT;
    390 
    391 	end = list + len;
    392 	cell = fdt_getprop(blob, node, "reg", &len);
    393 	if (!cell)
    394 		return -ENOENT;
    395 
    396 	for (idx = 0, info = &flash_info[0]; list < end;) {
    397 		addr = fdt_translate_address((void *)blob, node, cell + idx);
    398 		size = fdt_addr_to_cpu(cell[idx + addrc]);
    399 		len = strlen(list);
    400 		if (!strncmp(list, "nvm", len)) {
    401 			/* NVM controller */
    402 			nvm_regs_p = ioremap(addr, size);
    403 		} else if (!strncmp(list, "bank", 4)) {
    404 			/* Flash bank: use kseg0 cached address */
    405 			pic32_flash_bank_init(info, CKSEG0ADDR(addr), size);
    406 			info++;
    407 		}
    408 		idx += addrc + sizec;
    409 		list += len + 1;
    410 	}
    411 
    412 	/* disable flash write/erase operations */
    413 	writel(NVM_WREN, &nvm_regs_p->ctrl.clr);
    414 
    415 #if (CONFIG_SYS_MONITOR_BASE >= CONFIG_SYS_FLASH_BASE)
    416 	/* monitor protection ON by default */
    417 	flash_protect(FLAG_PROTECT_SET,
    418 		      CONFIG_SYS_MONITOR_BASE,
    419 		      CONFIG_SYS_MONITOR_BASE + monitor_flash_len - 1,
    420 		      &flash_info[0]);
    421 #endif
    422 
    423 #ifdef CONFIG_ENV_IS_IN_FLASH
    424 	/* ENV protection ON by default */
    425 	flash_protect(FLAG_PROTECT_SET,
    426 		      CONFIG_ENV_ADDR,
    427 		      CONFIG_ENV_ADDR + CONFIG_ENV_SECT_SIZE - 1,
    428 		      &flash_info[0]);
    429 #endif
    430 	return 0;
    431 }
    432 
    433 static const struct udevice_id pic32_flash_ids[] = {
    434 	{ .compatible = "microchip,pic32mzda-flash" },
    435 	{}
    436 };
    437 
    438 U_BOOT_DRIVER(pic32_flash) = {
    439 	.name	= "pic32_flash",
    440 	.id	= UCLASS_MTD,
    441 	.of_match = pic32_flash_ids,
    442 	.probe	= pic32_flash_probe,
    443 };
    444