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authorblogic <blogic@3c298f89-4303-0410-b956-a3cf2f4a3e73>2012-10-05 10:12:53 +0000
committerblogic <blogic@3c298f89-4303-0410-b956-a3cf2f4a3e73>2012-10-05 10:12:53 +0000
commit5c105d9f3fd086aff195d3849dcf847d6b0bd927 (patch)
tree1229a11f725bfa58aa7c57a76898553bb5f6654a /target/linux/ar71xx/patches-3.3/406-mtd-m25p80-allow-to-specify-max-read-size.patch
downloadopenwrt-5c105d9f3fd086aff195d3849dcf847d6b0bd927.tar.gz
openwrt-5c105d9f3fd086aff195d3849dcf847d6b0bd927.zip
branch Attitude Adjustment
git-svn-id: svn://svn.openwrt.org/openwrt/branches/attitude_adjustment@33625 3c298f89-4303-0410-b956-a3cf2f4a3e73
Diffstat (limited to 'target/linux/ar71xx/patches-3.3/406-mtd-m25p80-allow-to-specify-max-read-size.patch')
-rw-r--r--target/linux/ar71xx/patches-3.3/406-mtd-m25p80-allow-to-specify-max-read-size.patch112
1 files changed, 112 insertions, 0 deletions
diff --git a/target/linux/ar71xx/patches-3.3/406-mtd-m25p80-allow-to-specify-max-read-size.patch b/target/linux/ar71xx/patches-3.3/406-mtd-m25p80-allow-to-specify-max-read-size.patch
new file mode 100644
index 000000000..8861c615f
--- /dev/null
+++ b/target/linux/ar71xx/patches-3.3/406-mtd-m25p80-allow-to-specify-max-read-size.patch
@@ -0,0 +1,112 @@
+--- a/drivers/mtd/devices/m25p80.c
++++ b/drivers/mtd/devices/m25p80.c
+@@ -100,6 +100,7 @@ struct m25p {
+ u16 addr_width;
+ u8 erase_opcode;
+ u8 *command;
++ size_t max_read_len;
+ };
+
+ static inline struct m25p *mtd_to_m25p(struct mtd_info *mtd)
+@@ -352,6 +353,7 @@ static int m25p80_read(struct mtd_info *
+ struct m25p *flash = mtd_to_m25p(mtd);
+ struct spi_transfer t[2];
+ struct spi_message m;
++ loff_t ofs;
+
+ pr_debug("%s: %s from 0x%08x, len %zd\n", dev_name(&flash->spi->dev),
+ __func__, (u32)from, len);
+@@ -374,8 +376,6 @@ static int m25p80_read(struct mtd_info *
+ t[0].len = m25p_cmdsz(flash) + FAST_READ_DUMMY_BYTE;
+ spi_message_add_tail(&t[0], &m);
+
+- t[1].rx_buf = buf;
+- t[1].len = len;
+ spi_message_add_tail(&t[1], &m);
+
+ /* Byte count starts at zero. */
+@@ -383,13 +383,6 @@ static int m25p80_read(struct mtd_info *
+
+ 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.
+@@ -397,11 +390,44 @@ static int m25p80_read(struct mtd_info *
+
+ /* Set up the write data buffer. */
+ flash->command[0] = OPCODE_READ;
+- m25p_addr2cmd(flash, from, flash->command);
+
+- spi_sync(flash->spi, &m);
++ 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);
+
+- *retlen = m.actual_length - m25p_cmdsz(flash) - FAST_READ_DUMMY_BYTE;
++ done = m.actual_length - m25p_cmdsz(flash) -
++ FAST_READ_DUMMY_BYTE;
++ if (done != readlen) {
++ mutex_unlock(&flash->lock);
++ return 1;
++ }
++
++ ofs += done;
++ len -= done;
++ }
++
++ *retlen = ofs;
+
+ mutex_unlock(&flash->lock);
+
+@@ -925,6 +951,12 @@ static int __devinit m25p_probe(struct s
+ 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 */
+ };
+