target/linux/brcm47xx/patches-3.10/051-mtd_bcm47xxsflash_implement_polling_chip_status.patch

   1 commit 7026e9844112fa33e5ffcd562daf0c919b16a9d1
   2 Author: Rafał Miłecki <zajec5@gmail.com>
   3 Date:   Sun Mar 24 21:51:31 2013 +0100
   4
   5     mtd: bcm47xxsflash: implement polling chip status
   6
   7     Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
   8     Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
   9
  10 --- a/drivers/mtd/devices/bcm47xxsflash.c
  11 +++ b/drivers/mtd/devices/bcm47xxsflash.c
  12 @@ -1,6 +1,7 @@
  13  #include <linux/kernel.h>
  14  #include <linux/module.h>
  15  #include <linux/slab.h>
  16 +#include <linux/delay.h>
  17  #include <linux/mtd/mtd.h>
  18  #include <linux/platform_device.h>
  19  #include <linux/bcma/bcma.h>
  20 @@ -12,6 +13,57 @@ MODULE_DESCRIPTION("Serial flash driver
  21
  22  static const char * const probes[] = { "bcm47xxpart", NULL };
  23
  24 +/**************************************************
  25 + * Various helpers
  26 + **************************************************/
  27 +
  28 +static void bcm47xxsflash_cmd(struct bcm47xxsflash *b47s, u32 opcode)
  29 +{
  30 +       int i;
  31 +
  32 +       b47s->cc_write(b47s, BCMA_CC_FLASHCTL, BCMA_CC_FLASHCTL_START | opcode);
  33 +       for (i = 0; i < 1000; i++) {
  34 +               if (!(b47s->cc_read(b47s, BCMA_CC_FLASHCTL) &
  35 +                     BCMA_CC_FLASHCTL_BUSY))
  36 +                       return;
  37 +               cpu_relax();
  38 +       }
  39 +       pr_err("Control command failed (timeout)!\n");
  40 +}
  41 +
  42 +static int bcm47xxsflash_poll(struct bcm47xxsflash *b47s, int timeout)
  43 +{
  44 +       unsigned long deadline = jiffies + timeout;
  45 +
  46 +       do {
  47 +               switch (b47s->type) {
  48 +               case BCM47XXSFLASH_TYPE_ST:
  49 +                       bcm47xxsflash_cmd(b47s, OPCODE_ST_RDSR);
  50 +                       if (!(b47s->cc_read(b47s, BCMA_CC_FLASHDATA) &
  51 +                             SR_ST_WIP))
  52 +                               return 0;
  53 +                       break;
  54 +               case BCM47XXSFLASH_TYPE_ATMEL:
  55 +                       bcm47xxsflash_cmd(b47s, OPCODE_AT_STATUS);
  56 +                       if (b47s->cc_read(b47s, BCMA_CC_FLASHDATA) &
  57 +                           SR_AT_READY)
  58 +                               return 0;
  59 +                       break;
  60 +               }
  61 +
  62 +               cpu_relax();
  63 +               udelay(1);
  64 +       } while (!time_after_eq(jiffies, deadline));
  65 +
  66 +       pr_err("Timeout waiting for flash to be ready!\n");
  67 +
  68 +       return -EBUSY;
  69 +}
  70 +
  71 +/**************************************************
  72 + * MTD ops
  73 + **************************************************/
  74 +
  75  static int bcm47xxsflash_read(struct mtd_info *mtd, loff_t from, size_t len,
  76                               size_t *retlen, u_char *buf)
  77  {
  78 @@ -97,6 +149,9 @@ static int bcm47xxsflash_bcma_probe(stru
  79                 goto err_dev_reg;
  80         }
  81
  82 +       if (bcm47xxsflash_poll(b47s, HZ / 10))
  83 +               pr_warn("Serial flash busy\n");
  84 +
  85         return 0;
  86
  87  err_dev_reg: