target/linux/ramips/patches-3.18/0044-mtd-add-chunked-read-io-to-m25p80.patch

   1 --- a/drivers/mtd/devices/m25p80.c
   2 +++ b/drivers/mtd/devices/m25p80.c
   3 @@ -19,6 +19,7 @@
   4  #include <linux/errno.h>
   5  #include <linux/module.h>
   6  #include <linux/device.h>
   7 +#include <linux/of.h>
   8
   9  #include <linux/mtd/mtd.h>
  10  #include <linux/mtd/partitions.h>
  11 @@ -32,6 +33,7 @@ struct m25p {
  12         struct spi_device       *spi;
  13         struct spi_nor          spi_nor;
  14         struct mtd_info         mtd;
  15 +       u16                     chunk_size;
  16         u8                      command[MAX_CMD_SIZE];
  17  };
  18
  19 @@ -157,6 +159,61 @@ static int m25p80_read(struct spi_nor *n
  20         return 0;
  21  }
  22
  23 +static void m25p80_chunked_write(struct spi_nor *nor, loff_t _from, size_t _len,
  24 +                       size_t *_retlen, const u_char *_buf)
  25 +{
  26 +       struct m25p *flash = nor->priv;
  27 +       int chunk_size;
  28 +       int retlen = 0;
  29 +
  30 +       chunk_size = flash->chunk_size;
  31 +       if (!chunk_size)
  32 +               chunk_size = _len;
  33 +
  34 +       if (nor->addr_width > 3)
  35 +               chunk_size -= nor->addr_width - 3;
  36 +
  37 +       while (retlen < _len) {
  38 +               size_t len = min_t(int, chunk_size, _len - retlen);
  39 +               const u_char *buf = _buf + retlen;
  40 +               loff_t from = _from + retlen;
  41 +
  42 +               nor->wait_till_ready(nor);
  43 +               nor->write_reg(nor, SPINOR_OP_WREN, NULL, 0, 0);
  44 +
  45 +               m25p80_write(nor, from, len, &retlen, buf);
  46 +       }
  47 +       *_retlen += retlen;
  48 +}
  49 +
  50 +static int m25p80_chunked_read(struct spi_nor *nor, loff_t _from, size_t _len,
  51 +                       size_t *_retlen, u_char *_buf)
  52 +{
  53 +       struct m25p *flash = nor->priv;
  54 +       int chunk_size;
  55 +
  56 +       chunk_size = flash->chunk_size;
  57 +       if (!chunk_size)
  58 +               chunk_size = _len;
  59 +
  60 +       *_retlen = 0;
  61 +
  62 +       while (*_retlen < _len) {
  63 +               size_t len = min_t(int, chunk_size, _len - *_retlen);
  64 +               u_char *buf = _buf + *_retlen;
  65 +               loff_t from = _from + *_retlen;
  66 +               int retlen = 0;
  67 +               int ret = m25p80_read(nor, from, len, &retlen, buf);
  68 +
  69 +               if (ret)
  70 +                       return ret;
  71 +
  72 +               *_retlen += retlen;
  73 +       }
  74 +
  75 +       return 0;
  76 +}
  77 +
  78  static int m25p80_erase(struct spi_nor *nor, loff_t offset)
  79  {
  80         struct m25p *flash = nor->priv;
  81 @@ -197,6 +254,7 @@ static int m25p_probe(struct spi_device
  82         struct spi_nor *nor;
  83         enum read_mode mode = SPI_NOR_NORMAL;
  84         char *flash_name = NULL;
  85 +       u32 val;
  86         int ret;
  87
  88         data = dev_get_platdata(&spi->dev);
  89 @@ -244,6 +302,14 @@ static int m25p_probe(struct spi_device
  90         if (ret)
  91                 return ret;
  92
  93 +       if (spi->dev.of_node &&
  94 +           !of_property_read_u32(spi->dev.of_node, "m25p,chunked-io", &val)) {
  95 +               dev_warn(&spi->dev, "using chunked io\n");
  96 +               nor->read = m25p80_chunked_read;
  97 +               nor->write = m25p80_chunked_write;
  98 +               flash->chunk_size = val;
  99 +       }
 100 +
 101         ppdata.of_node = spi->dev.of_node;
 102
 103         return mtd_device_parse_register(&flash->mtd, NULL, &ppdata,