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