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 <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 };