113 lines
2.8 KiB
Diff
113 lines
2.8 KiB
Diff
--- 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);
|
|
|
|
@@ -924,6 +950,12 @@ 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 */
|
|
};
|
|
|