drivers/bcma/driver_chipcommon_sflash.c

   1 /*
   2  * Broadcom specific AMBA
   3  * ChipCommon serial flash interface
   4  *
   5  * Licensed under the GNU/GPL. See COPYING for details.
   6  */
   7
   8 #include <linux/platform_device.h>
   9 #include <linux/bcma/bcma.h>
  10
  11 #include "bcma_private.h"
  12
  13 static struct resource bcma_sflash_resource = {
  14         .name   = "bcma_sflash",
  15         .start  = BCMA_SFLASH,
  16         .end    = 0,
  17         .flags  = IORESOURCE_MEM | IORESOURCE_READONLY,
  18 };
  19
  20 struct platform_device bcma_sflash_dev = {
  21         .name           = "bcma_sflash",
  22         .resource       = &bcma_sflash_resource,
  23         .num_resources  = 1,
  24 };
  25
  26 struct bcma_sflash_tbl_e {
  27         char *name;
  28         u32 id;
  29         u32 blocksize;
  30         u16 numblocks;
  31 };
  32
  33 static struct bcma_sflash_tbl_e bcma_sflash_st_tbl[] = {
  34         { "", 0x14, 0x10000, 32, },
  35         { 0 },
  36 };
  37
  38 static struct bcma_sflash_tbl_e bcma_sflash_sst_tbl[] = {
  39         { 0 },
  40 };
  41
  42 static struct bcma_sflash_tbl_e bcma_sflash_at_tbl[] = {
  43         { 0 },
  44 };
  45
  46 static void bcma_sflash_cmd(struct bcma_drv_cc *cc, u32 opcode)
  47 {
  48         int i;
  49         bcma_cc_write32(cc, BCMA_CC_FLASHCTL,
  50                         BCMA_CC_FLASHCTL_START | opcode);
  51         for (i = 0; i < 1000; i++) {
  52                 if (!(bcma_cc_read32(cc, BCMA_CC_FLASHCTL) &
  53                       BCMA_CC_FLASHCTL_BUSY))
  54                         return;
  55                 cpu_relax();
  56         }
  57         bcma_err(cc->core->bus, "SFLASH control command failed (timeout)!\n");
  58 }
  59
  60 /* Initialize serial flash access */
  61 int bcma_sflash_init(struct bcma_drv_cc *cc)
  62 {
  63         struct bcma_bus *bus = cc->core->bus;
  64         struct bcma_sflash *sflash = &cc->sflash;
  65         struct bcma_sflash_tbl_e *e;
  66         u32 id, id2;
  67
  68         switch (cc->capabilities & BCMA_CC_CAP_FLASHT) {
  69         case BCMA_CC_FLASHT_STSER:
  70                 bcma_sflash_cmd(cc, BCMA_CC_FLASHCTL_ST_DP);
  71
  72                 bcma_cc_write32(cc, BCMA_CC_FLASHADDR, 0);
  73                 bcma_sflash_cmd(cc, BCMA_CC_FLASHCTL_ST_RES);
  74                 id = bcma_cc_read32(cc, BCMA_CC_FLASHDATA);
  75
  76                 bcma_cc_write32(cc, BCMA_CC_FLASHADDR, 1);
  77                 bcma_sflash_cmd(cc, BCMA_CC_FLASHCTL_ST_RES);
  78                 id2 = bcma_cc_read32(cc, BCMA_CC_FLASHDATA);
  79
  80                 switch (id) {
  81                 case 0xbf:
  82                         for (e = bcma_sflash_sst_tbl; e->name; e++) {
  83                                 if (e->id == id2)
  84                                         break;
  85                         }
  86                         break;
  87                 default:
  88                         for (e = bcma_sflash_st_tbl; e->name; e++) {
  89                                 if (e->id == id)
  90                                         break;
  91                         }
  92                         break;
  93                 }
  94                 if (!e->name) {
  95                         bcma_err(bus, "Unsupported ST serial flash (id: 0x%X, id2: 0x%X)\n", id, id2);
  96                         return -ENOTSUPP;
  97                 }
  98
  99                 break;
 100         case BCMA_CC_FLASHT_ATSER:
 101                 bcma_sflash_cmd(cc, BCMA_CC_FLASHCTL_AT_STATUS);
 102                 id = bcma_cc_read32(cc, BCMA_CC_FLASHDATA) & 0x3c;
 103
 104                 for (e = bcma_sflash_at_tbl; e->name; e++) {
 105                         if (e->id == id)
 106                                 break;
 107                 }
 108                 if (!e->name) {
 109                         bcma_err(bus, "Unsupported Atmel serial flash (id: 0x%X)\n", id);
 110                         return -ENOTSUPP;
 111                 }
 112
 113                 break;
 114         default:
 115                 bcma_err(bus, "Unsupported flash type\n");
 116                 return -ENOTSUPP;
 117         }
 118
 119         sflash->window = BCMA_SFLASH;
 120         sflash->blocksize = e->blocksize;
 121         sflash->numblocks = e->numblocks;
 122         sflash->size = sflash->blocksize * sflash->numblocks;
 123         sflash->present = true;
 124
 125         bcma_info(bus, "Found %s serial flash (size: %dKiB, blocksize: 0x%X, blocks: %d)\n",
 126                   e->name, sflash->size / 1024, sflash->blocksize,
 127                   sflash->numblocks);
 128
 129         /* Prepare platform device, but don't register it yet. It's too early,
 130          * malloc (required by device_private_init) is not available yet. */
 131         bcma_sflash_dev.resource[0].end = bcma_sflash_dev.resource[0].start +
 132                                           sflash->size;
 133         bcma_sflash_dev.dev.platform_data = sflash;
 134
 135         return 0;
 136 }