target/linux/ramips/patches-4.4/0054-mtd-add-chunked-read-io-to-m25p80.patch

   1 --- a/drivers/mtd/spi-nor/spi-nor.c
   2 +++ b/drivers/mtd/spi-nor/spi-nor.c
   3 @@ -1011,6 +1011,66 @@ write_err:
   4         return ret;
   5  }
   6
   7 +static int spi_nor_chunked_write(struct mtd_info *mtd, loff_t _to, size_t _len,
   8 +                                size_t *_retlen, const u_char *_buf)
   9 +{
  10 +       struct spi_nor *nor = mtd_to_spi_nor(mtd);
  11 +       int chunk_size;
  12 +       int retlen = 0;
  13 +       int ret;
  14 +
  15 +       chunk_size = nor->chunk_size;
  16 +       if (!chunk_size)
  17 +               chunk_size = _len;
  18 +
  19 +       if (nor->addr_width > 3)
  20 +               chunk_size -= nor->addr_width - 3;
  21 +
  22 +       while (retlen < _len) {
  23 +               size_t len = min_t(int, chunk_size, _len - retlen);
  24 +               const u_char *buf = _buf + retlen;
  25 +               loff_t to = _to + retlen;
  26 +
  27 +               if (nor->flags & SNOR_F_SST)
  28 +                       ret = sst_write(mtd, to, len, &retlen, buf);
  29 +               else
  30 +                       ret = spi_nor_write(mtd, to, len, &retlen, buf);
  31 +               if (ret)
  32 +                       return ret;
  33 +       }
  34 +
  35 +       *_retlen += retlen;
  36 +       return 0;
  37 +}
  38 +
  39 +static int spi_nor_chunked_read(struct mtd_info *mtd, loff_t _from, size_t _len,
  40 +                               size_t *_retlen, u_char *_buf)
  41 +{
  42 +       struct spi_nor *nor = mtd_to_spi_nor(mtd);
  43 +       int chunk_size;
  44 +       int ret;
  45 +
  46 +       chunk_size = nor->chunk_size;
  47 +       if (!chunk_size)
  48 +               chunk_size = _len;
  49 +
  50 +       *_retlen = 0;
  51 +       while (*_retlen < _len) {
  52 +               size_t len = min_t(int, chunk_size, _len - *_retlen);
  53 +               u_char *buf = _buf + *_retlen;
  54 +               loff_t from = _from + *_retlen;
  55 +               int retlen = 0;
  56 +
  57 +               ret = spi_nor_read(mtd, from, len, &retlen, buf);
  58 +               if (ret)
  59 +                       return ret;
  60 +
  61 +               *_retlen += retlen;
  62 +       }
  63 +
  64 +       return 0;
  65 +}
  66 +
  67  static int macronix_quad_enable(struct spi_nor *nor)
  68  {
  69         int ret, val;
  70 @@ -1232,10 +1292,12 @@ int spi_nor_scan(struct spi_nor *nor, co
  71         }
  72
  73         /* sst nor chips use AAI word program */
  74 -       if (info->flags & SST_WRITE)
  75 +       if (info->flags & SST_WRITE) {
  76                 mtd->_write = sst_write;
  77 -       else
  78 +               nor->flags |= SNOR_F_SST;
  79 +       } else {
  80                 mtd->_write = spi_nor_write;
  81 +       }
  82
  83         if (info->flags & USE_FSR)
  84                 nor->flags |= SNOR_F_USE_FSR;
  85 @@ -1263,11 +1325,20 @@ int spi_nor_scan(struct spi_nor *nor, co
  86         mtd->writebufsize = nor->page_size;
  87
  88         if (np) {
  89 +               u32 val;
  90 +
  91                 /* If we were instantiated by DT, use it */
  92                 if (of_property_read_bool(np, "m25p,fast-read"))
  93                         nor->flash_read = SPI_NOR_FAST;
  94                 else
  95                         nor->flash_read = SPI_NOR_NORMAL;
  96 +
  97 +               if (!of_property_read_u32(np, "m25p,chunked-io", &val)) {
  98 +                       dev_info(dev, "using chunked io (size=%d)\n", val);
  99 +                       mtd->_read = spi_nor_chunked_read;
 100 +                       mtd->_write = spi_nor_chunked_write;
 101 +                       nor->chunk_size = val;
 102 +               }
 103         } else {
 104                 /* If we weren't instantiated by DT, default to fast-read */
 105                 nor->flash_read = SPI_NOR_FAST;
 106 --- a/include/linux/mtd/spi-nor.h
 107 +++ b/include/linux/mtd/spi-nor.h
 108 @@ -116,6 +116,7 @@ enum spi_nor_ops {
 109
 110  enum spi_nor_option_flags {
 111         SNOR_F_USE_FSR          = BIT(0),
 112 +       SNOR_F_SST              = BIT(1),
 113  };
 114
 115  /**
 116 @@ -156,6 +157,7 @@ struct spi_nor {
 117         struct device           *dev;
 118         struct device_node      *flash_node;
 119         u32                     page_size;
 120 +       u16                     chunk_size;
 121         u8                      addr_width;
 122         u8                      erase_opcode;
 123         u8                      read_opcode;