target/linux/brcm63xx/patches-3.18/345-MIPS-BCM63XX-fixup-mapped-SPI-flash-access-on-boot.patch

   1 From 1cacd0f7b0d35f8e3d3f8a69ecb3b5e436d6b9e8 Mon Sep 17 00:00:00 2001
   2 From: Jonas Gorski <jogo@openwrt.org>
   3 Date: Sun, 22 Dec 2013 13:25:25 +0100
   4 Subject: [PATCH 52/56] MIPS: BCM63XX: fixup mapped SPI flash access on boot
   5
   6 Some bootloaders leave the flash access in an invalid state with dual
   7 read enabled; fix it by disabling it and falling back to simple fast
   8 reads.
   9
  10 Signed-off-by: Jonas Gorski <jogo@openwrt.org>
  11 ---
  12  arch/mips/bcm63xx/dev-flash.c | 36 ++++++++++++++++++++++++++++++++++++
  13  1 file changed, 36 insertions(+)
  14
  15 --- a/arch/mips/bcm63xx/dev-flash.c
  16 +++ b/arch/mips/bcm63xx/dev-flash.c
  17 @@ -110,9 +110,46 @@ static int __init bcm63xx_detect_flash_t
  18         }
  19  }
  20
  21 +#define HSSPI_FLASH_CTRL_REG           0x14
  22 +#define FLASH_CTRL_READ_OPCODE_MASK    0xff
  23 +#define FLASH_CTRL_ADDR_BYTES_MASK     (0x3 << 8)
  24 +#define FLASH_CTRL_ADDR_BYTES_2                (0 << 8)
  25 +#define FLASH_CTRL_ADDR_BYTES_3                (1 << 8)
  26 +#define FLASH_CTRL_ADDR_BYTES_4                (2 << 8)
  27 +#define FLASH_CTRL_MB_EN               (1 << 23)
  28 +
  29  void __init bcm63xx_flash_detect(void)
  30  {
  31         flash_type = bcm63xx_detect_flash_type();
  32 +
  33 +       /* reduce flash mapping to single i/o reads for safety */
  34 +       if (flash_type == BCM63XX_FLASH_TYPE_SERIAL &&
  35 +           (BCMCPU_IS_6318() || BCMCPU_IS_6328() || BCMCPU_IS_6362() ||
  36 +            BCMCPU_IS_63268())) {
  37 +               u32 val = bcm_rset_readl(RSET_HSSPI, HSSPI_FLASH_CTRL_REG);
  38 +
  39 +               if (!(val & FLASH_CTRL_MB_EN))
  40 +                       return;
  41 +
  42 +               val &= ~FLASH_CTRL_MB_EN;
  43 +               val &= ~FLASH_CTRL_READ_OPCODE_MASK;
  44 +
  45 +               switch (val & FLASH_CTRL_ADDR_BYTES_MASK) {
  46 +               case FLASH_CTRL_ADDR_BYTES_3:
  47 +                       val |= 0x0b; /* OPCODE_FAST_READ */
  48 +                       break;
  49 +               case FLASH_CTRL_ADDR_BYTES_4:
  50 +                       val |= 0x0c; /* OPCODE_FAST_READ_4B */
  51 +                       break;
  52 +               case FLASH_CTRL_ADDR_BYTES_2:
  53 +               default:
  54 +                       pr_warn("unsupported address byte mode (%x), not fixing up\n",
  55 +                               val & FLASH_CTRL_ADDR_BYTES_MASK);
  56 +                       return;
  57 +               }
  58 +
  59 +               bcm_rset_writel(RSET_HSSPI, val, HSSPI_FLASH_CTRL_REG);
  60 +       }
  61  }
  62
  63  int __init bcm63xx_flash_register(void)