arch/ppc64/kernel/pmac_nvram.c

   1 /*
   2  *  arch/ppc/platforms/pmac_nvram.c
   3  *
   4  *  Copyright (C) 2002 Benjamin Herrenschmidt (benh@kernel.crashing.org)
   5  *
   6  *  This program is free software; you can redistribute it and/or
   7  *  modify it under the terms of the GNU General Public License
   8  *  as published by the Free Software Foundation; either version
   9  *  2 of the License, or (at your option) any later version.
  10  *
  11  *  Todo: - add support for the OF persistent properties
  12  */
  13 #include <linux/config.h>
  14 #include <linux/module.h>
  15 #include <linux/kernel.h>
  16 #include <linux/stddef.h>
  17 #include <linux/string.h>
  18 #include <linux/init.h>
  19 #include <linux/slab.h>
  20 #include <linux/delay.h>
  21 #include <linux/errno.h>
  22 #include <linux/bootmem.h>
  23 #include <linux/completion.h>
  24 #include <linux/spinlock.h>
  25 #include <asm/sections.h>
  26 #include <asm/io.h>
  27 #include <asm/system.h>
  28 #include <asm/prom.h>
  29 #include <asm/machdep.h>
  30 #include <asm/nvram.h>
  31
  32 #define DEBUG
  33
  34 #ifdef DEBUG
  35 #define DBG(x...) printk(x)
  36 #else
  37 #define DBG(x...)
  38 #endif
  39
  40 #define NVRAM_SIZE              0x2000  /* 8kB of non-volatile RAM */
  41
  42 #define CORE99_SIGNATURE        0x5a
  43 #define CORE99_ADLER_START      0x14
  44
  45 /* On Core99, nvram is either a sharp, a micron or an AMD flash */
  46 #define SM_FLASH_STATUS_DONE    0x80
  47 #define SM_FLASH_STATUS_ERR     0x38
  48
  49 #define SM_FLASH_CMD_ERASE_CONFIRM      0xd0
  50 #define SM_FLASH_CMD_ERASE_SETUP        0x20
  51 #define SM_FLASH_CMD_RESET              0xff
  52 #define SM_FLASH_CMD_WRITE_SETUP        0x40
  53 #define SM_FLASH_CMD_CLEAR_STATUS       0x50
  54 #define SM_FLASH_CMD_READ_STATUS        0x70
  55
  56 /* CHRP NVRAM header */
  57 struct chrp_header {
  58   u8            signature;
  59   u8            cksum;
  60   u16           len;
  61   char          name[12];
  62   u8            data[0];
  63 };
  64
  65 struct core99_header {
  66   struct chrp_header    hdr;
  67   u32                   adler;
  68   u32                   generation;
  69   u32                   reserved[2];
  70 };
  71
  72 /*
  73  * Read and write the non-volatile RAM on PowerMacs and CHRP machines.
  74  */
  75 static volatile unsigned char *nvram_data;
  76 static int core99_bank = 0;
  77 // XXX Turn that into a sem
  78 static DEFINE_SPINLOCK(nv_lock);
  79
  80 extern int system_running;
  81
  82 static int (*core99_write_bank)(int bank, u8* datas);
  83 static int (*core99_erase_bank)(int bank);
  84
  85 static char *nvram_image __pmacdata;
  86
  87
  88 static ssize_t __pmac core99_nvram_read(char *buf, size_t count, loff_t *index)
  89 {
  90         int i;
  91
  92         if (nvram_image == NULL)
  93                 return -ENODEV;
  94         if (*index > NVRAM_SIZE)
  95                 return 0;
  96
  97         i = *index;
  98         if (i + count > NVRAM_SIZE)
  99                 count = NVRAM_SIZE - i;
 100
 101         memcpy(buf, &nvram_image[i], count);
 102         *index = i + count;
 103         return count;
 104 }
 105
 106 static ssize_t __pmac core99_nvram_write(char *buf, size_t count, loff_t *index)
 107 {
 108         int i;
 109
 110         if (nvram_image == NULL)
 111                 return -ENODEV;
 112         if (*index > NVRAM_SIZE)
 113                 return 0;
 114
 115         i = *index;
 116         if (i + count > NVRAM_SIZE)
 117                 count = NVRAM_SIZE - i;
 118
 119         memcpy(&nvram_image[i], buf, count);
 120         *index = i + count;
 121         return count;
 122 }
 123
 124 static ssize_t __pmac core99_nvram_size(void)
 125 {
 126         if (nvram_image == NULL)
 127                 return -ENODEV;
 128         return NVRAM_SIZE;
 129 }
 130
 131 static u8 __pmac chrp_checksum(struct chrp_header* hdr)
 132 {
 133         u8 *ptr;
 134         u16 sum = hdr->signature;
 135         for (ptr = (u8 *)&hdr->len; ptr < hdr->data; ptr++)
 136                 sum += *ptr;
 137         while (sum > 0xFF)
 138                 sum = (sum & 0xFF) + (sum>>8);
 139         return sum;
 140 }
 141
 142 static u32 __pmac core99_calc_adler(u8 *buffer)
 143 {
 144         int cnt;
 145         u32 low, high;
 146
 147         buffer += CORE99_ADLER_START;
 148         low = 1;
 149         high = 0;
 150         for (cnt=0; cnt<(NVRAM_SIZE-CORE99_ADLER_START); cnt++) {
 151                 if ((cnt % 5000) == 0) {
 152                         high  %= 65521UL;
 153                         high %= 65521UL;
 154                 }
 155                 low += buffer[cnt];
 156                 high += low;
 157         }
 158         low  %= 65521UL;
 159         high %= 65521UL;
 160
 161         return (high << 16) | low;
 162 }
 163
 164 static u32 __pmac core99_check(u8* datas)
 165 {
 166         struct core99_header* hdr99 = (struct core99_header*)datas;
 167
 168         if (hdr99->hdr.signature != CORE99_SIGNATURE) {
 169                 DBG("Invalid signature\n");
 170                 return 0;
 171         }
 172         if (hdr99->hdr.cksum != chrp_checksum(&hdr99->hdr)) {
 173                 DBG("Invalid checksum\n");
 174                 return 0;
 175         }
 176         if (hdr99->adler != core99_calc_adler(datas)) {
 177                 DBG("Invalid adler\n");
 178                 return 0;
 179         }
 180         return hdr99->generation;
 181 }
 182
 183 static int __pmac sm_erase_bank(int bank)
 184 {
 185         int stat, i;
 186         unsigned long timeout;
 187
 188         u8* base = (u8 *)nvram_data + core99_bank*NVRAM_SIZE;
 189
 190         DBG("nvram: Sharp/Micron Erasing bank %d...\n", bank);
 191
 192         out_8(base, SM_FLASH_CMD_ERASE_SETUP);
 193         out_8(base, SM_FLASH_CMD_ERASE_CONFIRM);
 194         timeout = 0;
 195         do {
 196                 if (++timeout > 1000000) {
 197                         printk(KERN_ERR "nvram: Sharp/Miron flash erase timeout !\n");
 198                         break;
 199                 }
 200                 out_8(base, SM_FLASH_CMD_READ_STATUS);
 201                 stat = in_8(base);
 202         } while (!(stat & SM_FLASH_STATUS_DONE));
 203
 204         out_8(base, SM_FLASH_CMD_CLEAR_STATUS);
 205         out_8(base, SM_FLASH_CMD_RESET);
 206
 207         for (i=0; i<NVRAM_SIZE; i++)
 208                 if (base[i] != 0xff) {
 209                         printk(KERN_ERR "nvram: Sharp/Micron flash erase failed !\n");
 210                         return -ENXIO;
 211                 }
 212         return 0;
 213 }
 214
 215 static int __pmac sm_write_bank(int bank, u8* datas)
 216 {
 217         int i, stat = 0;
 218         unsigned long timeout;
 219
 220         u8* base = (u8 *)nvram_data + core99_bank*NVRAM_SIZE;
 221
 222         DBG("nvram: Sharp/Micron Writing bank %d...\n", bank);
 223
 224         for (i=0; i<NVRAM_SIZE; i++) {
 225                 out_8(base+i, SM_FLASH_CMD_WRITE_SETUP);
 226                 udelay(1);
 227                 out_8(base+i, datas[i]);
 228                 timeout = 0;
 229                 do {
 230                         if (++timeout > 1000000) {
 231                                 printk(KERN_ERR "nvram: Sharp/Micron flash write timeout !\n");
 232                                 break;
 233                         }
 234                         out_8(base, SM_FLASH_CMD_READ_STATUS);
 235                         stat = in_8(base);
 236                 } while (!(stat & SM_FLASH_STATUS_DONE));
 237                 if (!(stat & SM_FLASH_STATUS_DONE))
 238                         break;
 239         }
 240         out_8(base, SM_FLASH_CMD_CLEAR_STATUS);
 241         out_8(base, SM_FLASH_CMD_RESET);
 242         for (i=0; i<NVRAM_SIZE; i++)
 243                 if (base[i] != datas[i]) {
 244                         printk(KERN_ERR "nvram: Sharp/Micron flash write failed !\n");
 245                         return -ENXIO;
 246                 }
 247         return 0;
 248 }
 249
 250 static int __pmac amd_erase_bank(int bank)
 251 {
 252         int i, stat = 0;
 253         unsigned long timeout;
 254
 255         u8* base = (u8 *)nvram_data + core99_bank*NVRAM_SIZE;
 256
 257         DBG("nvram: AMD Erasing bank %d...\n", bank);
 258
 259         /* Unlock 1 */
 260         out_8(base+0x555, 0xaa);
 261         udelay(1);
 262         /* Unlock 2 */
 263         out_8(base+0x2aa, 0x55);
 264         udelay(1);
 265
 266         /* Sector-Erase */
 267         out_8(base+0x555, 0x80);
 268         udelay(1);
 269         out_8(base+0x555, 0xaa);
 270         udelay(1);
 271         out_8(base+0x2aa, 0x55);
 272         udelay(1);
 273         out_8(base, 0x30);
 274         udelay(1);
 275
 276         timeout = 0;
 277         do {
 278                 if (++timeout > 1000000) {
 279                         printk(KERN_ERR "nvram: AMD flash erase timeout !\n");
 280                         break;
 281                 }
 282                 stat = in_8(base) ^ in_8(base);
 283         } while (stat != 0);
 284
 285         /* Reset */
 286         out_8(base, 0xf0);
 287         udelay(1);
 288
 289         for (i=0; i<NVRAM_SIZE; i++)
 290                 if (base[i] != 0xff) {
 291                         printk(KERN_ERR "nvram: AMD flash erase failed !\n");
 292                         return -ENXIO;
 293                 }
 294         return 0;
 295 }
 296
 297 static int __pmac amd_write_bank(int bank, u8* datas)
 298 {
 299         int i, stat = 0;
 300         unsigned long timeout;
 301
 302         u8* base = (u8 *)nvram_data + core99_bank*NVRAM_SIZE;
 303
 304         DBG("nvram: AMD Writing bank %d...\n", bank);
 305
 306         for (i=0; i<NVRAM_SIZE; i++) {
 307                 /* Unlock 1 */
 308                 out_8(base+0x555, 0xaa);
 309                 udelay(1);
 310                 /* Unlock 2 */
 311                 out_8(base+0x2aa, 0x55);
 312                 udelay(1);
 313
 314                 /* Write single word */
 315                 out_8(base+0x555, 0xa0);
 316                 udelay(1);
 317                 out_8(base+i, datas[i]);
 318
 319                 timeout = 0;
 320                 do {
 321                         if (++timeout > 1000000) {
 322                                 printk(KERN_ERR "nvram: AMD flash write timeout !\n");
 323                                 break;
 324                         }
 325                         stat = in_8(base) ^ in_8(base);
 326                 } while (stat != 0);
 327                 if (stat != 0)
 328                         break;
 329         }
 330
 331         /* Reset */
 332         out_8(base, 0xf0);
 333         udelay(1);
 334
 335         for (i=0; i<NVRAM_SIZE; i++)
 336                 if (base[i] != datas[i]) {
 337                         printk(KERN_ERR "nvram: AMD flash write failed !\n");
 338                         return -ENXIO;
 339                 }
 340         return 0;
 341 }
 342
 343
 344 static int __pmac core99_nvram_sync(void)
 345 {
 346         struct core99_header* hdr99;
 347         unsigned long flags;
 348
 349         spin_lock_irqsave(&nv_lock, flags);
 350         if (!memcmp(nvram_image, (u8*)nvram_data + core99_bank*NVRAM_SIZE,
 351                 NVRAM_SIZE))
 352                 goto bail;
 353
 354         DBG("Updating nvram...\n");
 355
 356         hdr99 = (struct core99_header*)nvram_image;
 357         hdr99->generation++;
 358         hdr99->hdr.signature = CORE99_SIGNATURE;
 359         hdr99->hdr.cksum = chrp_checksum(&hdr99->hdr);
 360         hdr99->adler = core99_calc_adler(nvram_image);
 361         core99_bank = core99_bank ? 0 : 1;
 362         if (core99_erase_bank)
 363                 if (core99_erase_bank(core99_bank)) {
 364                         printk("nvram: Error erasing bank %d\n", core99_bank);
 365                         goto bail;
 366                 }
 367         if (core99_write_bank)
 368                 if (core99_write_bank(core99_bank, nvram_image))
 369                         printk("nvram: Error writing bank %d\n", core99_bank);
 370  bail:
 371         spin_unlock_irqrestore(&nv_lock, flags);
 372
 373         return 0;
 374 }
 375
 376 int __init pmac_nvram_init(void)
 377 {
 378         struct device_node *dp;
 379         u32 gen_bank0, gen_bank1;
 380         int i;
 381
 382         dp = find_devices("nvram");
 383         if (dp == NULL) {
 384                 printk(KERN_ERR "Can't find NVRAM device\n");
 385                 return -ENODEV;
 386         }
 387         if (!device_is_compatible(dp, "nvram,flash")) {
 388                 printk(KERN_ERR "Incompatible type of NVRAM\n");
 389                 return -ENXIO;
 390         }
 391
 392         nvram_image = alloc_bootmem(NVRAM_SIZE);
 393         if (nvram_image == NULL) {
 394                 printk(KERN_ERR "nvram: can't allocate ram image\n");
 395                 return -ENOMEM;
 396         }
 397         nvram_data = ioremap(dp->addrs[0].address, NVRAM_SIZE*2);
 398
 399         DBG("nvram: Checking bank 0...\n");
 400
 401         gen_bank0 = core99_check((u8 *)nvram_data);
 402         gen_bank1 = core99_check((u8 *)nvram_data + NVRAM_SIZE);
 403         core99_bank = (gen_bank0 < gen_bank1) ? 1 : 0;
 404
 405         DBG("nvram: gen0=%d, gen1=%d\n", gen_bank0, gen_bank1);
 406         DBG("nvram: Active bank is: %d\n", core99_bank);
 407
 408         for (i=0; i<NVRAM_SIZE; i++)
 409                 nvram_image[i] = nvram_data[i + core99_bank*NVRAM_SIZE];
 410
 411         ppc_md.nvram_read       = core99_nvram_read;
 412         ppc_md.nvram_write      = core99_nvram_write;
 413         ppc_md.nvram_size       = core99_nvram_size;
 414         ppc_md.nvram_sync       = core99_nvram_sync;
 415
 416         /*
 417          * Maybe we could be smarter here though making an exclusive list
 418          * of known flash chips is a bit nasty as older OF didn't provide us
 419          * with a useful "compatible" entry. A solution would be to really
 420          * identify the chip using flash id commands and base ourselves on
 421          * a list of known chips IDs
 422          */
 423         if (device_is_compatible(dp, "amd-0137")) {
 424                 core99_erase_bank = amd_erase_bank;
 425                 core99_write_bank = amd_write_bank;
 426         } else {
 427                 core99_erase_bank = sm_erase_bank;
 428                 core99_write_bank = sm_write_bank;
 429         }
 430
 431         return 0;
 432 }
 433
 434 int __pmac pmac_get_partition(int partition)
 435 {
 436         struct nvram_partition *part;
 437         const char *name;
 438         int sig;
 439
 440         switch(partition) {
 441         case pmac_nvram_OF:
 442                 name = "common";
 443                 sig = NVRAM_SIG_SYS;
 444                 break;
 445         case pmac_nvram_XPRAM:
 446                 name = "APL,MacOS75";
 447                 sig = NVRAM_SIG_OS;
 448                 break;
 449         case pmac_nvram_NR:
 450         default:
 451                 /* Oldworld stuff */
 452                 return -ENODEV;
 453         }
 454
 455         part = nvram_find_partition(sig, name);
 456         if (part == NULL)
 457                 return 0;
 458
 459         return part->index;
 460 }
 461
 462 u8 __pmac pmac_xpram_read(int xpaddr)
 463 {
 464         int offset = pmac_get_partition(pmac_nvram_XPRAM);
 465         loff_t index;
 466         u8 buf;
 467         ssize_t count;
 468
 469         if (offset < 0 || xpaddr < 0 || xpaddr > 0x100)
 470                 return 0xff;
 471         index = offset + xpaddr;
 472
 473         count = ppc_md.nvram_read(&buf, 1, &index);
 474         if (count != 1)
 475                 return 0xff;
 476         return buf;
 477 }
 478
 479 void __pmac pmac_xpram_write(int xpaddr, u8 data)
 480 {
 481         int offset = pmac_get_partition(pmac_nvram_XPRAM);
 482         loff_t index;
 483         u8 buf;
 484
 485         if (offset < 0 || xpaddr < 0 || xpaddr > 0x100)
 486                 return;
 487         index = offset + xpaddr;
 488         buf = data;
 489
 490         ppc_md.nvram_write(&buf, 1, &index);
 491 }
 492
 493 EXPORT_SYMBOL(pmac_get_partition);
 494 EXPORT_SYMBOL(pmac_xpram_read);
 495 EXPORT_SYMBOL(pmac_xpram_write);