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