target/linux/ramips/patches-4.9/0054-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 @@ -1453,6 +1453,67 @@ 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 +       u32 addr_width = nor->addr_width + !!(nor->flags & SNOR_F_4B_EXT_ADDR);
  12 +       int chunk_size;
  13 +       int retlen = 0;
  14 +       int ret;
  15 +
  16 +       chunk_size = nor->chunk_size;
  17 +       if (!chunk_size)
  18 +               chunk_size = _len;
  19 +
  20 +       if (addr_width > 3)
  21 +               chunk_size -= addr_width - 3;
  22 +
  23 +       while (retlen < _len) {
  24 +               size_t len = min_t(int, chunk_size, _len - retlen);
  25 +               const u_char *buf = _buf + retlen;
  26 +               loff_t to = _to + retlen;
  27 +
  28 +               if (nor->flags & SNOR_F_SST)
  29 +                       ret = sst_write(mtd, to, len, &retlen, buf);
  30 +               else
  31 +                       ret = spi_nor_write(mtd, to, len, &retlen, buf);
  32 +               if (ret)
  33 +                       return ret;
  34 +       }
  35 +
  36 +       *_retlen += retlen;
  37 +       return 0;
  38 +}
  39 +
  40 +static int spi_nor_chunked_read(struct mtd_info *mtd, loff_t _from, size_t _len,
  41 +                               size_t *_retlen, u_char *_buf)
  42 +{
  43 +       struct spi_nor *nor = mtd_to_spi_nor(mtd);
  44 +       int chunk_size;
  45 +       int ret;
  46 +
  47 +       chunk_size = nor->chunk_size;
  48 +       if (!chunk_size)
  49 +               chunk_size = _len;
  50 +
  51 +       *_retlen = 0;
  52 +       while (*_retlen < _len) {
  53 +               size_t len = min_t(int, chunk_size, _len - *_retlen);
  54 +               u_char *buf = _buf + *_retlen;
  55 +               loff_t from = _from + *_retlen;
  56 +               int retlen = 0;
  57 +
  58 +               ret = spi_nor_read(mtd, from, len, &retlen, buf);
  59 +               if (ret)
  60 +                       return ret;
  61 +
  62 +               *_retlen += retlen;
  63 +       }
  64 +
  65 +       return 0;
  66 +}
  67 +
  68  static int macronix_quad_enable(struct spi_nor *nor)
  69  {
  70         int ret, val;
  71 @@ -1702,10 +1763,12 @@ int spi_nor_scan(struct spi_nor *nor, co
  72         }
  73
  74         /* sst nor chips use AAI word program */
  75 -       if (info->flags & SST_WRITE)
  76 +       if (info->flags & SST_WRITE) {
  77                 mtd->_write = sst_write;
  78 -       else
  79 +               nor->flags |= SNOR_F_SST;
  80 +       } else {
  81                 mtd->_write = spi_nor_write;
  82 +       }
  83
  84         if (info->flags & USE_FSR)
  85                 nor->flags |= SNOR_F_USE_FSR;
  86 @@ -1735,11 +1798,20 @@ int spi_nor_scan(struct spi_nor *nor, co
  87         mtd->writebufsize = nor->page_size;
  88
  89         if (np) {
  90 +               u32 val;
  91 +
  92                 /* If we were instantiated by DT, use it */
  93                 if (of_property_read_bool(np, "m25p,fast-read"))
  94                         nor->flash_read = SPI_NOR_FAST;
  95                 else
  96                         nor->flash_read = SPI_NOR_NORMAL;
  97 +
  98 +               if (!of_property_read_u32(np, "m25p,chunked-io", &val)) {
  99 +                       dev_info(dev, "using chunked io (size=%d)\n", val);
 100 +                       mtd->_read = spi_nor_chunked_read;
 101 +                       mtd->_write = spi_nor_chunked_write;
 102 +                       nor->chunk_size = val;
 103 +               }
 104         } else {
 105                 /* If we weren't instantiated by DT, default to fast-read */
 106                 nor->flash_read = SPI_NOR_FAST;
 107 --- a/include/linux/mtd/spi-nor.h
 108 +++ b/include/linux/mtd/spi-nor.h
 109 @@ -143,6 +143,7 @@ enum spi_nor_option_flags {
 110         SNOR_F_S3AN_ADDR_DEFAULT = BIT(3),
 111         SNOR_F_READY_XSR_RDY    = BIT(4),
 112         SNOR_F_4B_EXT_ADDR      = BIT(5),
 113 +       SNOR_F_SST              = BIT(6),
 114  };
 115
 116  /**
 117 @@ -182,6 +183,7 @@ struct spi_nor {
 118         struct mutex            lock;
 119         struct device           *dev;
 120         u32                     page_size;
 121 +       u16                     chunk_size;
 122         u8                      addr_width;
 123         u8                      erase_opcode;
 124         u8                      read_opcode;