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--- 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 */
};
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