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Diffstat (limited to 'target/linux/ar71xx/patches-3.8/406-mtd-m25p80-allow-to-specify-max-read-size.patch')
-rw-r--r--target/linux/ar71xx/patches-3.8/406-mtd-m25p80-allow-to-specify-max-read-size.patch109
1 files changed, 109 insertions, 0 deletions
diff --git a/target/linux/ar71xx/patches-3.8/406-mtd-m25p80-allow-to-specify-max-read-size.patch b/target/linux/ar71xx/patches-3.8/406-mtd-m25p80-allow-to-specify-max-read-size.patch
new file mode 100644
index 0000000..be308c6
--- /dev/null
+++ b/target/linux/ar71xx/patches-3.8/406-mtd-m25p80-allow-to-specify-max-read-size.patch
@@ -0,0 +1,109 @@
+--- a/drivers/mtd/devices/m25p80.c
++++ b/drivers/mtd/devices/m25p80.c
+@@ -93,6 +93,7 @@ struct m25p {
+ u8 erase_opcode;
+ u8 *command;
+ bool fast_read;
++ size_t max_read_len;
+ };
+
+ static inline struct m25p *mtd_to_m25p(struct mtd_info *mtd)
+@@ -344,6 +345,7 @@ static int m25p80_read(struct mtd_info *
+ struct spi_transfer t[2];
+ struct spi_message m;
+ uint8_t opcode;
++ loff_t ofs;
+
+ pr_debug("%s: %s from 0x%08x, len %zd\n", dev_name(&flash->spi->dev),
+ __func__, (u32)from, len);
+@@ -359,19 +361,10 @@ static int m25p80_read(struct mtd_info *
+ t[0].len = m25p_cmdsz(flash) + (flash->fast_read ? 1 : 0);
+ spi_message_add_tail(&t[0], &m);
+
+- t[1].rx_buf = buf;
+- t[1].len = len;
+ spi_message_add_tail(&t[1], &m);
+
+ mutex_lock(&flash->lock);
+
+- /* Wait till previous write/erase is done. */
+- if (wait_till_ready(flash)) {
+- /* REVISIT status return?? */
+- mutex_unlock(&flash->lock);
+- return 1;
+- }
+-
+ /* FIXME switch to OPCODE_FAST_READ. It's required for higher
+ * clocks; and at this writing, every chip this driver handles
+ * supports that opcode.
+@@ -380,13 +373,43 @@ static int m25p80_read(struct mtd_info *
+ /* Set up the write data buffer. */
+ opcode = flash->fast_read ? OPCODE_FAST_READ : OPCODE_NORM_READ;
+ flash->command[0] = opcode;
+- m25p_addr2cmd(flash, from, flash->command);
++ ofs = 0;
++ while (len) {
++ size_t readlen;
++ size_t done;
++ int ret;
++
++ ret = wait_till_ready(flash);
++ if (ret) {
++ mutex_unlock(&flash->lock);
++ return 1;
++ }
++
++ if (flash->max_read_len > 0 &&
++ flash->max_read_len < len)
++ readlen = flash->max_read_len;
++ else
++ readlen = len;
++
++ t[1].rx_buf = buf + ofs;
++ t[1].len = readlen;
++
++ m25p_addr2cmd(flash, from + ofs, flash->command);
++
++ spi_sync(flash->spi, &m);
+
+- spi_sync(flash->spi, &m);
++ done = m.actual_length - m25p_cmdsz(flash) -
++ (flash->fast_read ? 1 : 0);
++ if (done != readlen) {
++ mutex_unlock(&flash->lock);
++ return 1;
++ }
+
+- *retlen = m.actual_length - m25p_cmdsz(flash) -
+- (flash->fast_read ? 1 : 0);
++ ofs += done;
++ len -= done;
++ }
+
++ *retlen = ofs;
+ mutex_unlock(&flash->lock);
+
+ return 0;
+@@ -916,6 +939,12 @@ static int m25p_probe(struct spi_device
+ flash->mtd._erase = m25p80_erase;
+ flash->mtd._read = m25p80_read;
+
++ if (data && data->max_read_len) {
++ flash->max_read_len = data->max_read_len;
++ dev_warn(&spi->dev, "max_read_len set to %d bytes\n",
++ flash->max_read_len);
++ }
++
+ /* sst flash chips use AAI word program */
+ if (JEDEC_MFR(info->jedec_id) == CFI_MFR_SST)
+ flash->mtd._write = sst_write;
+--- a/include/linux/spi/flash.h
++++ b/include/linux/spi/flash.h
+@@ -25,6 +25,7 @@ struct flash_platform_data {
+
+ char *type;
+
++ size_t max_read_len;
+ /* we'll likely add more ... use JEDEC IDs, etc */
+ };
+