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 +159,58 @@ 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 +       while (retlen < _len) {
  35 +               size_t len = min_t(int, chunk_size, _len - retlen);
  36 +               const u_char *buf = _buf + retlen;
  37 +               loff_t from = _from + retlen;
  38 +
  39 +               nor->wait_till_ready(nor);
  40 +               nor->write_reg(nor, SPINOR_OP_WREN, NULL, 0, 0);
  41 +
  42 +               m25p80_write(nor, from, len, &retlen, buf);
  43 +       }
  44 +       *_retlen += retlen;
  45 +}
  46 +
  47 +static int m25p80_chunked_read(struct spi_nor *nor, loff_t _from, size_t _len,
  48 +                       size_t *_retlen, u_char *_buf)
  49 +{
  50 +       struct m25p *flash = nor->priv;
  51 +       int chunk_size;
  52 +
  53 +       chunk_size = flash->chunk_size;
  54 +       if (!chunk_size)
  55 +               chunk_size = _len;
  56 +
  57 +       *_retlen = 0;
  58 +
  59 +       while (*_retlen < _len) {
  60 +               size_t len = min_t(int, chunk_size, _len - *_retlen);
  61 +               u_char *buf = _buf + *_retlen;
  62 +               loff_t from = _from + *_retlen;
  63 +               int retlen = 0;
  64 +               int ret = m25p80_read(nor, from, len, &retlen, buf);
  65 +
  66 +               if (ret)
  67 +                       return ret;
  68 +
  69 +               *_retlen += retlen;
  70 +       }
  71 +
  72 +       return 0;
  73 +}
  74 +
  75  static int m25p80_erase(struct spi_nor *nor, loff_t offset)
  76  {
  77         struct m25p *flash = nor->priv;
  78 @@ -197,6 +251,7 @@ static int m25p_probe(struct spi_device
  79         struct spi_nor *nor;
  80         enum read_mode mode = SPI_NOR_NORMAL;
  81         char *flash_name = NULL;
  82 +       u32 val;
  83         int ret;
  84
  85         data = dev_get_platdata(&spi->dev);
  86 @@ -244,6 +299,14 @@ static int m25p_probe(struct spi_device
  87         if (ret)
  88                 return ret;
  89
  90 +       if (spi->dev.of_node &&
  91 +           !of_property_read_u32(spi->dev.of_node, "m25p,chunked-io", &val)) {
  92 +               dev_warn(&spi->dev, "using chunked io\n");
  93 +               nor->read = m25p80_chunked_read;
  94 +               nor->write = m25p80_chunked_write;
  95 +               flash->chunk_size = val;
  96 +       }
  97 +
  98         ppdata.of_node = spi->dev.of_node;
  99
 100         return mtd_device_parse_register(&flash->mtd, NULL, &ppdata,