target/linux/ramips/patches-3.14/0044-mtd-add-chunked-read-io-to-m25p80.patch

   1 From b6d5d4c3d595b4cfb6a052ac7151fdb1d9a776ea Mon Sep 17 00:00:00 2001
   2 From: John Crispin <blogic@openwrt.org>
   3 Date: Sun, 27 Jul 2014 09:58:09 +0100
   4 Subject: [PATCH 44/57] mtd: add chunked read io to m25p80
   5
   6 Signed-off-by: John Crispin <blogic@openwrt.org>
   7 Signed-off-by: Felix Fietkau <nbd@openwrt.org>
   8 ---
   9  drivers/mtd/devices/m25p80.c |  128 ++++++++++++++++++++++++++++++++++++++++++
  10  1 file changed, 128 insertions(+)
  11
  12 --- a/drivers/mtd/devices/m25p80.c
  13 +++ b/drivers/mtd/devices/m25p80.c
  14 @@ -110,6 +110,7 @@ struct m25p {
  15         struct mtd_info         mtd;
  16         u16                     page_size;
  17         u16                     addr_width;
  18 +       u16                     chunk_size;
  19         u8                      erase_opcode;
  20         u8                      read_opcode;
  21         u8                      program_opcode;
  22 @@ -562,6 +563,89 @@ static int m25p80_read(struct mtd_info *
  23         return 0;
  24  }
  25
  26 +static int m25p80_read_chunked(struct mtd_info *mtd, loff_t from, size_t len,
  27 +       size_t *retlen, u_char *buf)
  28 +{
  29 +       struct m25p *flash = mtd_to_m25p(mtd);
  30 +       struct spi_transfer t[2];
  31 +       struct spi_message m;
  32 +       uint8_t opcode;
  33 +       int idx, rlen;
  34 +
  35 +       pr_debug("%s: %s from 0x%08x, len %zd\n", dev_name(&flash->spi->dev),
  36 +                       __func__, (u32)from, len);
  37 +
  38 +       mutex_lock(&flash->lock);
  39 +       /* Wait till previous write/erase is done. */
  40 +       if (wait_till_ready(flash)) {
  41 +               /* REVISIT status return?? */
  42 +               mutex_unlock(&flash->lock);
  43 +               return 1;
  44 +       }
  45 +
  46 +       spi_message_init(&m);
  47 +       memset(t, 0, (sizeof t));
  48 +
  49 +       t[0].tx_buf = flash->command;
  50 +       t[0].len = m25p_cmdsz(flash);
  51 +       spi_message_add_tail(&t[0], &m);
  52 +       spi_message_add_tail(&t[1], &m);
  53 +
  54 +       *retlen = 0;
  55 +
  56 +       for (idx = 0; idx < len; idx += rlen) {
  57 +               rlen = min_t(int, flash->chunk_size, len - idx);
  58 +
  59 +               if (idx)
  60 +                       wait_till_ready(flash);
  61 +
  62 +               t[1].rx_buf = &buf[idx];
  63 +               t[1].len = rlen;
  64 +
  65 +               /* Set up the write data buffer. */
  66 +               opcode = OPCODE_NORM_READ;
  67 +               flash->command[0] = opcode;
  68 +               m25p_addr2cmd(flash, from + idx, flash->command);
  69 +
  70 +               spi_sync(flash->spi, &m);
  71 +
  72 +               *retlen += m.actual_length - m25p_cmdsz(flash);
  73 +       }
  74 +
  75 +       mutex_unlock(&flash->lock);
  76 +
  77 +       return 0;
  78 +}
  79 +
  80 +static int m25p80_write_data(struct m25p *flash, struct spi_message *m,
  81 +                            struct spi_transfer *t, int to)
  82 +{
  83 +       const void *buf = t->tx_buf;
  84 +       int len = t->len;
  85 +       int retlen = 0;
  86 +       int chunk_size;
  87 +
  88 +       chunk_size = flash->chunk_size;
  89 +       if (!chunk_size)
  90 +               chunk_size = len;
  91 +
  92 +       while (retlen < len) {
  93 +               t->tx_buf = buf + retlen;
  94 +               t->len = min_t(int, chunk_size, len - retlen);
  95 +
  96 +               if (retlen)
  97 +                       wait_till_ready(flash);
  98 +
  99 +               write_enable(flash);
 100 +               m25p_addr2cmd(flash, to + retlen, flash->command);
 101 +               spi_sync(flash->spi, m);
 102 +
 103 +               retlen += m->actual_length - m25p_cmdsz(flash);
 104 +       }
 105 +
 106 +       return retlen;
 107 +}
 108 +
 109  /*
 110   * Write an address range to the flash chip.  Data must be written in
 111   * FLASH_PAGESIZE chunks.  The address range may be any size provided
 112 @@ -596,11 +680,8 @@ static int m25p80_write(struct mtd_info
 113                 return 1;
 114         }
 115
 116 -       write_enable(flash);
 117 -
 118         /* Set up the opcode in the write buffer. */
 119         flash->command[0] = flash->program_opcode;
 120 -       m25p_addr2cmd(flash, to, flash->command);
 121
 122         page_offset = to & (flash->page_size - 1);
 123
 124 @@ -608,9 +689,7 @@ static int m25p80_write(struct mtd_info
 125         if (page_offset + len <= flash->page_size) {
 126                 t[1].len = len;
 127
 128 -               spi_sync(flash->spi, &m);
 129 -
 130 -               *retlen = m.actual_length - m25p_cmdsz(flash);
 131 +               *retlen = m25p80_write_data(flash, &m, &t[1], to);
 132         } else {
 133                 u32 i;
 134
 135 @@ -618,9 +697,7 @@ static int m25p80_write(struct mtd_info
 136                 page_size = flash->page_size - page_offset;
 137
 138                 t[1].len = page_size;
 139 -               spi_sync(flash->spi, &m);
 140 -
 141 -               *retlen = m.actual_length - m25p_cmdsz(flash);
 142 +               *retlen = m25p80_write_data(flash, &m, &t[1], to);
 143
 144                 /* write everything in flash->page_size chunks */
 145                 for (i = page_size; i < len; i += page_size) {
 146 @@ -628,19 +705,12 @@ static int m25p80_write(struct mtd_info
 147                         if (page_size > flash->page_size)
 148                                 page_size = flash->page_size;
 149
 150 -                       /* write the next page to flash */
 151 -                       m25p_addr2cmd(flash, to + i, flash->command);
 152 -
 153                         t[1].tx_buf = buf + i;
 154                         t[1].len = page_size;
 155
 156                         wait_till_ready(flash);
 157
 158 -                       write_enable(flash);
 159 -
 160 -                       spi_sync(flash->spi, &m);
 161 -
 162 -                       *retlen += m.actual_length - m25p_cmdsz(flash);
 163 +                       *retlen += m25p80_write_data(flash, &m, &t[1], to + i);
 164                 }
 165         }
 166
 167 @@ -1105,6 +1175,7 @@ static int m25p_probe(struct spi_device
 168         struct mtd_part_parser_data     ppdata;
 169         struct device_node *np = spi->dev.of_node;
 170         int ret;
 171 +       u32 val;
 172
 173         /* Platform data helps sort out which chip type we have, as
 174          * well as how this board partitions it.  If we don't have
 175 @@ -1187,6 +1258,12 @@ static int m25p_probe(struct spi_device
 176         flash->mtd._erase = m25p80_erase;
 177         flash->mtd._read = m25p80_read;
 178
 179 +       if (np && !of_property_read_u32(np, "m25p,chunked-io", &val)) {
 180 +               dev_warn(&spi->dev, "using chunked io\n");
 181 +               flash->mtd._read = m25p80_read_chunked;
 182 +               flash->chunk_size = val;
 183 +       }
 184 +
 185         /* flash protection support for STmicro chips */
 186         if (JEDEC_MFR(info->jedec_id) == CFI_MFR_ST) {
 187                 flash->mtd._lock = m25p80_lock;