drivers/mtd/pic32_flash.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2015
   4  * Cristian Birsan <cristian.birsan@microchip.com>
   5  * Purna Chandra Mandal <purna.mandal@microchip.com>
   6  */
   7
   8 #include <common.h>
   9 #include <cpu_func.h>
  10 #include <dm.h>
  11 #include <fdt_support.h>
  12 #include <flash.h>
  13 #include <init.h>
  14 #include <irq_func.h>
  15 #include <linux/bitops.h>
  16 #include <mach/pic32.h>
  17 #include <wait_bit.h>
  18
  19 DECLARE_GLOBAL_DATA_PTR;
  20
  21 /* NVM Controller registers */
  22 struct pic32_reg_nvm {
  23         struct pic32_reg_atomic ctrl;
  24         struct pic32_reg_atomic key;
  25         struct pic32_reg_atomic addr;
  26         struct pic32_reg_atomic data;
  27 };
  28
  29 /* NVM operations */
  30 #define NVMOP_NOP               0
  31 #define NVMOP_WORD_WRITE        1
  32 #define NVMOP_PAGE_ERASE        4
  33
  34 /* NVM control bits */
  35 #define NVM_WR                  BIT(15)
  36 #define NVM_WREN                BIT(14)
  37 #define NVM_WRERR               BIT(13)
  38 #define NVM_LVDERR              BIT(12)
  39
  40 /* NVM programming unlock register */
  41 #define LOCK_KEY                0x0
  42 #define UNLOCK_KEY1             0xaa996655
  43 #define UNLOCK_KEY2             0x556699aa
  44
  45 /*
  46  * PIC32 flash banks consist of number of pages, each page
  47  * into number of rows and rows into number of words.
  48  * Here we will maintain page information instead of sector.
  49  */
  50 flash_info_t flash_info[CONFIG_SYS_MAX_FLASH_BANKS];
  51 static struct pic32_reg_nvm *nvm_regs_p;
  52
  53 static inline void flash_initiate_operation(u32 nvmop)
  54 {
  55         /* set operation */
  56         writel(nvmop, &nvm_regs_p->ctrl.raw);
  57
  58         /* enable flash write */
  59         writel(NVM_WREN, &nvm_regs_p->ctrl.set);
  60
  61         /* unlock sequence */
  62         writel(LOCK_KEY, &nvm_regs_p->key.raw);
  63         writel(UNLOCK_KEY1, &nvm_regs_p->key.raw);
  64         writel(UNLOCK_KEY2, &nvm_regs_p->key.raw);
  65
  66         /* initiate operation */
  67         writel(NVM_WR, &nvm_regs_p->ctrl.set);
  68 }
  69
  70 static int flash_wait_till_busy(const char *func, ulong timeout)
  71 {
  72         int ret = wait_for_bit_le32(&nvm_regs_p->ctrl.raw,
  73                                     NVM_WR, false, timeout, false);
  74
  75         return ret ? ERR_TIMEOUT : ERR_OK;
  76 }
  77
  78 static inline int flash_complete_operation(void)
  79 {
  80         u32 tmp;
  81
  82         tmp = readl(&nvm_regs_p->ctrl.raw);
  83         if (tmp & NVM_WRERR) {
  84                 printf("Error in Block Erase - Lock Bit may be set!\n");
  85                 flash_initiate_operation(NVMOP_NOP);
  86                 return ERR_PROTECTED;
  87         }
  88
  89         if (tmp & NVM_LVDERR) {
  90                 printf("Error in Block Erase - low-vol detected!\n");
  91                 flash_initiate_operation(NVMOP_NOP);
  92                 return ERR_NOT_ERASED;
  93         }
  94
  95         /* disable flash write or erase operation */
  96         writel(NVM_WREN, &nvm_regs_p->ctrl.clr);
  97
  98         return ERR_OK;
  99 }
 100
 101 /*
 102  * Erase flash sectors, returns:
 103  * ERR_OK - OK
 104  * ERR_INVAL - invalid sector arguments
 105  * ERR_TIMEOUT - write timeout
 106  * ERR_NOT_ERASED - Flash not erased
 107  * ERR_UNKNOWN_FLASH_VENDOR - incorrect flash
 108  */
 109 int flash_erase(flash_info_t *info, int s_first, int s_last)
 110 {
 111         ulong sect_start, sect_end, flags;
 112         int prot, sect;
 113         int rc;
 114
 115         if ((info->flash_id & FLASH_VENDMASK) != FLASH_MAN_MCHP) {
 116                 printf("Can't erase unknown flash type %08lx - aborted\n",
 117                        info->flash_id);
 118                 return ERR_UNKNOWN_FLASH_VENDOR;
 119         }
 120
 121         if ((s_first < 0) || (s_first > s_last)) {
 122                 printf("- no sectors to erase\n");
 123                 return ERR_INVAL;
 124         }
 125
 126         prot = 0;
 127         for (sect = s_first; sect <= s_last; ++sect) {
 128                 if (info->protect[sect])
 129                         prot++;
 130         }
 131
 132         if (prot)
 133                 printf("- Warning: %d protected sectors will not be erased!\n",
 134                        prot);
 135         else
 136                 printf("\n");
 137
 138         /* erase on unprotected sectors */
 139         for (sect = s_first; sect <= s_last; sect++) {
 140                 if (info->protect[sect])
 141                         continue;
 142
 143                 /* disable interrupts */
 144                 flags = disable_interrupts();
 145
 146                 /* write destination page address (physical) */
 147                 sect_start = CPHYSADDR(info->start[sect]);
 148                 writel(sect_start, &nvm_regs_p->addr.raw);
 149
 150                 /* page erase */
 151                 flash_initiate_operation(NVMOP_PAGE_ERASE);
 152
 153                 /* wait */
 154                 rc = flash_wait_till_busy(__func__,
 155                                           CONFIG_SYS_FLASH_ERASE_TOUT);
 156
 157                 /* re-enable interrupts if necessary */
 158                 if (flags)
 159                         enable_interrupts();
 160
 161                 if (rc != ERR_OK)
 162                         return rc;
 163
 164                 rc = flash_complete_operation();
 165                 if (rc != ERR_OK)
 166                         return rc;
 167
 168                 /*
 169                  * flash content is updated but cache might contain stale
 170                  * data, so invalidate dcache.
 171                  */
 172                 sect_end = info->start[sect] + info->size / info->sector_count;
 173                 invalidate_dcache_range(info->start[sect], sect_end);
 174         }
 175
 176         printf(" done\n");
 177         return ERR_OK;
 178 }
 179
 180 int page_erase(flash_info_t *info, int sect)
 181 {
 182         return 0;
 183 }
 184
 185 /* Write a word to flash */
 186 static int write_word(flash_info_t *info, ulong dest, ulong word)
 187 {
 188         ulong flags;
 189         int rc;
 190
 191         /* read flash to check if it is sufficiently erased */
 192         if ((readl((void __iomem *)dest) & word) != word) {
 193                 printf("Error, Flash not erased!\n");
 194                 return ERR_NOT_ERASED;
 195         }
 196
 197         /* disable interrupts */
 198         flags = disable_interrupts();
 199
 200         /* update destination page address (physical) */
 201         writel(CPHYSADDR(dest), &nvm_regs_p->addr.raw);
 202         writel(word, &nvm_regs_p->data.raw);
 203
 204         /* word write */
 205         flash_initiate_operation(NVMOP_WORD_WRITE);
 206
 207         /* wait for operation to complete */
 208         rc = flash_wait_till_busy(__func__, CONFIG_SYS_FLASH_WRITE_TOUT);
 209
 210         /* re-enable interrupts if necessary */
 211         if (flags)
 212                 enable_interrupts();
 213
 214         if (rc != ERR_OK)
 215                 return rc;
 216
 217         return flash_complete_operation();
 218 }
 219
 220 /*
 221  * Copy memory to flash, returns:
 222  * ERR_OK - OK
 223  * ERR_TIMEOUT - write timeout
 224  * ERR_NOT_ERASED - Flash not erased
 225  */
 226 int write_buff(flash_info_t *info, uchar *src, ulong addr, ulong cnt)
 227 {
 228         ulong dst, tmp_le, len = cnt;
 229         int i, l, rc;
 230         uchar *cp;
 231
 232         /* get lower word aligned address */
 233         dst = (addr & ~3);
 234
 235         /* handle unaligned start bytes */
 236         l = addr - dst;
 237         if (l != 0) {
 238                 tmp_le = 0;
 239                 for (i = 0, cp = (uchar *)dst; i < l; ++i, ++cp)
 240                         tmp_le |= *cp << (i * 8);
 241
 242                 for (; (i < 4) && (cnt > 0); ++i, ++src, --cnt, ++cp)
 243                         tmp_le |= *src << (i * 8);
 244
 245                 for (; (cnt == 0) && (i < 4); ++i, ++cp)
 246                         tmp_le |= *cp << (i * 8);
 247
 248                 rc = write_word(info, dst, tmp_le);
 249                 if (rc)
 250                         goto out;
 251
 252                 dst += 4;
 253         }
 254
 255         /* handle word aligned part */
 256         while (cnt >= 4) {
 257                 tmp_le = src[0] | src[1] << 8 | src[2] << 16 | src[3] << 24;
 258                 rc = write_word(info, dst, tmp_le);
 259                 if (rc)
 260                         goto out;
 261                 src += 4;
 262                 dst += 4;
 263                 cnt -= 4;
 264         }
 265
 266         if (cnt == 0) {
 267                 rc = ERR_OK;
 268                 goto out;
 269         }
 270
 271         /* handle unaligned tail bytes */
 272         tmp_le = 0;
 273         for (i = 0, cp = (uchar *)dst; (i < 4) && (cnt > 0); ++i, ++cp) {
 274                 tmp_le |= *src++ << (i * 8);
 275                 --cnt;
 276         }
 277
 278         for (; i < 4; ++i, ++cp)
 279                 tmp_le |= *cp << (i * 8);
 280
 281         rc = write_word(info, dst, tmp_le);
 282 out:
 283         /*
 284          * flash content updated by nvm controller but CPU cache might
 285          * have stale data, so invalidate dcache.
 286          */
 287         invalidate_dcache_range(addr, addr + len);
 288
 289         printf(" done\n");
 290         return rc;
 291 }
 292
 293 void flash_print_info(flash_info_t *info)
 294 {
 295         int i;
 296
 297         if (info->flash_id == FLASH_UNKNOWN) {
 298                 printf("missing or unknown FLASH type\n");
 299                 return;
 300         }
 301
 302         switch (info->flash_id & FLASH_VENDMASK) {
 303         case FLASH_MAN_MCHP:
 304                 printf("Microchip Technology ");
 305                 break;
 306         default:
 307                 printf("Unknown Vendor ");
 308                 break;
 309         }
 310
 311         switch (info->flash_id & FLASH_TYPEMASK) {
 312         case FLASH_MCHP100T:
 313                 printf("Internal (8 Mbit, 64 x 16k)\n");
 314                 break;
 315         default:
 316                 printf("Unknown Chip Type\n");
 317                 break;
 318         }
 319
 320         printf("  Size: %ld MB in %d Sectors\n",
 321                info->size >> 20, info->sector_count);
 322
 323         printf("  Sector Start Addresses:");
 324         for (i = 0; i < info->sector_count; ++i) {
 325                 if ((i % 5) == 0)
 326                         printf("\n   ");
 327
 328                 printf(" %08lX%s", info->start[i],
 329                        info->protect[i] ? " (RO)" : "     ");
 330         }
 331         printf("\n");
 332 }
 333
 334 unsigned long flash_init(void)
 335 {
 336         unsigned long size = 0;
 337         struct udevice *dev;
 338         int bank;
 339
 340         /* probe every MTD device */
 341         for (uclass_first_device(UCLASS_MTD, &dev); dev;
 342              uclass_next_device(&dev)) {
 343                 /* nop */
 344         }
 345
 346         /* calc total flash size */
 347         for (bank = 0; bank < CONFIG_SYS_MAX_FLASH_BANKS; ++bank)
 348                 size += flash_info[bank].size;
 349
 350         return size;
 351 }
 352
 353 static void pic32_flash_bank_init(flash_info_t *info,
 354                                   ulong base, ulong size)
 355 {
 356         ulong sect_size;
 357         int sect;
 358
 359         /* device & manufacturer code */
 360         info->flash_id = FLASH_MAN_MCHP | FLASH_MCHP100T;
 361         info->sector_count = CONFIG_SYS_MAX_FLASH_SECT;
 362         info->size = size;
 363
 364         /* update sector (i.e page) info */
 365         sect_size = info->size / info->sector_count;
 366         for (sect = 0; sect < info->sector_count; sect++) {
 367                 info->start[sect] = base;
 368                 /* protect each sector by default */
 369                 info->protect[sect] = 1;
 370                 base += sect_size;
 371         }
 372 }
 373
 374 static int pic32_flash_probe(struct udevice *dev)
 375 {
 376         void *blob = (void *)gd->fdt_blob;
 377         int node = dev_of_offset(dev);
 378         const char *list, *end;
 379         const fdt32_t *cell;
 380         unsigned long addr, size;
 381         int parent, addrc, sizec;
 382         flash_info_t *info;
 383         int len, idx;
 384
 385         /*
 386          * decode regs. there are multiple reg tuples, and they need to
 387          * match with reg-names.
 388          */
 389         parent = fdt_parent_offset(blob, node);
 390         fdt_support_default_count_cells(blob, parent, &addrc, &sizec);
 391         list = fdt_getprop(blob, node, "reg-names", &len);
 392         if (!list)
 393                 return -ENOENT;
 394
 395         end = list + len;
 396         cell = fdt_getprop(blob, node, "reg", &len);
 397         if (!cell)
 398                 return -ENOENT;
 399
 400         for (idx = 0, info = &flash_info[0]; list < end;) {
 401                 addr = fdt_translate_address((void *)blob, node, cell + idx);
 402                 size = fdt_addr_to_cpu(cell[idx + addrc]);
 403                 len = strlen(list);
 404                 if (!strncmp(list, "nvm", len)) {
 405                         /* NVM controller */
 406                         nvm_regs_p = ioremap(addr, size);
 407                 } else if (!strncmp(list, "bank", 4)) {
 408                         /* Flash bank: use kseg0 cached address */
 409                         pic32_flash_bank_init(info, CKSEG0ADDR(addr), size);
 410                         info++;
 411                 }
 412                 idx += addrc + sizec;
 413                 list += len + 1;
 414         }
 415
 416         /* disable flash write/erase operations */
 417         writel(NVM_WREN, &nvm_regs_p->ctrl.clr);
 418
 419 #if (CONFIG_SYS_MONITOR_BASE >= CONFIG_SYS_FLASH_BASE)
 420         /* monitor protection ON by default */
 421         flash_protect(FLAG_PROTECT_SET,
 422                       CONFIG_SYS_MONITOR_BASE,
 423                       CONFIG_SYS_MONITOR_BASE + monitor_flash_len - 1,
 424                       &flash_info[0]);
 425 #endif
 426
 427 #ifdef CONFIG_ENV_IS_IN_FLASH
 428         /* ENV protection ON by default */
 429         flash_protect(FLAG_PROTECT_SET,
 430                       CONFIG_ENV_ADDR,
 431                       CONFIG_ENV_ADDR + CONFIG_ENV_SECT_SIZE - 1,
 432                       &flash_info[0]);
 433 #endif
 434         return 0;
 435 }
 436
 437 static const struct udevice_id pic32_flash_ids[] = {
 438         { .compatible = "microchip,pic32mzda-flash" },
 439         {}
 440 };
 441
 442 U_BOOT_DRIVER(pic32_flash) = {
 443         .name   = "pic32_flash",
 444         .id     = UCLASS_MTD,
 445         .of_match = pic32_flash_ids,
 446         .probe  = pic32_flash_probe,
 447 };