target/linux/layerscape/patches-4.4/1081-mtd-spi-nor-provide-default-erase_sector-implementat.patch

   1 From 56bd0e13d8bc3b4486251b10ac9d2ba7434c21ee Mon Sep 17 00:00:00 2001
   2 From: Brian Norris <computersforpeace@gmail.com>
   3 Date: Tue, 10 Nov 2015 12:15:27 -0800
   4 Subject: [PATCH 081/113] mtd: spi-nor: provide default erase_sector
   5  implementation
   6
   7 Some spi-nor drivers perform sector erase by duplicating their
   8 write_reg() command. Let's not require that the driver fill this out,
   9 and provide a default instead.
  10
  11 Tested on m25p80.c and Medatek's MT8173 SPI NOR flash driver.
  12
  13 Signed-off-by: Brian Norris <computersforpeace@gmail.com>
  14 ---
  15  drivers/mtd/spi-nor/spi-nor.c |   37 +++++++++++++++++++++++++++++++++----
  16  include/linux/mtd/spi-nor.h   |    3 ++-
  17  2 files changed, 35 insertions(+), 5 deletions(-)
  18
  19 --- a/drivers/mtd/spi-nor/spi-nor.c
  20 +++ b/drivers/mtd/spi-nor/spi-nor.c
  21 @@ -38,6 +38,7 @@
  22  #define CHIP_ERASE_2MB_READY_WAIT_JIFFIES      (40UL * HZ)
  23
  24  #define SPI_NOR_MAX_ID_LEN     6
  25 +#define SPI_NOR_MAX_ADDR_WIDTH 4
  26
  27  struct flash_info {
  28         char            *name;
  29 @@ -314,6 +315,29 @@ static void spi_nor_unlock_and_unprep(st
  30  }
  31
  32  /*
  33 + * Initiate the erasure of a single sector
  34 + */
  35 +static int spi_nor_erase_sector(struct spi_nor *nor, u32 addr)
  36 +{
  37 +       u8 buf[SPI_NOR_MAX_ADDR_WIDTH];
  38 +       int i;
  39 +
  40 +       if (nor->erase)
  41 +               return nor->erase(nor, addr);
  42 +
  43 +       /*
  44 +        * Default implementation, if driver doesn't have a specialized HW
  45 +        * control
  46 +        */
  47 +       for (i = nor->addr_width - 1; i >= 0; i--) {
  48 +               buf[i] = addr & 0xff;
  49 +               addr >>= 8;
  50 +       }
  51 +
  52 +       return nor->write_reg(nor, nor->erase_opcode, buf, nor->addr_width);
  53 +}
  54 +
  55 +/*
  56   * Erase an address range on the nor chip.  The address range may extend
  57   * one or more erase sectors.  Return an error is there is a problem erasing.
  58   */
  59 @@ -372,10 +396,9 @@ static int spi_nor_erase(struct mtd_info
  60                 while (len) {
  61                         write_enable(nor);
  62
  63 -                       if (nor->erase(nor, addr)) {
  64 -                               ret = -EIO;
  65 +                       ret = spi_nor_erase_sector(nor, addr);
  66 +                       if (ret)
  67                                 goto erase_err;
  68 -                       }
  69
  70                         addr += mtd->erasesize;
  71                         len -= mtd->erasesize;
  72 @@ -1100,7 +1123,7 @@ static int set_quad_mode(struct spi_nor
  73  static int spi_nor_check(struct spi_nor *nor)
  74  {
  75         if (!nor->dev || !nor->read || !nor->write ||
  76 -               !nor->read_reg || !nor->write_reg || !nor->erase) {
  77 +               !nor->read_reg || !nor->write_reg) {
  78                 pr_err("spi-nor: please fill all the necessary fields!\n");
  79                 return -EINVAL;
  80         }
  81 @@ -1303,6 +1326,12 @@ int spi_nor_scan(struct spi_nor *nor, co
  82                 nor->addr_width = 3;
  83         }
  84
  85 +       if (nor->addr_width > SPI_NOR_MAX_ADDR_WIDTH) {
  86 +               dev_err(dev, "address width is too large: %u\n",
  87 +                       nor->addr_width);
  88 +               return -EINVAL;
  89 +       }
  90 +
  91         nor->read_dummy = spi_nor_read_dummy_cycles(nor);
  92
  93         dev_info(dev, "%s (%lld Kbytes)\n", info->name,
  94 --- a/include/linux/mtd/spi-nor.h
  95 +++ b/include/linux/mtd/spi-nor.h
  96 @@ -142,7 +142,8 @@ enum spi_nor_option_flags {
  97   * @read:              [DRIVER-SPECIFIC] read data from the SPI NOR
  98   * @write:             [DRIVER-SPECIFIC] write data to the SPI NOR
  99   * @erase:             [DRIVER-SPECIFIC] erase a sector of the SPI NOR
 100 - *                     at the offset @offs
 101 + *                     at the offset @offs; if not provided by the driver,
 102 + *                     spi-nor will send the erase opcode via write_reg()
 103   * @flash_lock:                [FLASH-SPECIFIC] lock a region of the SPI NOR
 104   * @flash_unlock:      [FLASH-SPECIFIC] unlock a region of the SPI NOR
 105   * @flash_is_locked:   [FLASH-SPECIFIC] check if a region of the SPI NOR is