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authorVignesh R <vigneshr@ti.com>2016-03-29 05:46:17 (GMT)
committerBrian Norris <computersforpeace@gmail.com>2016-04-05 18:06:57 (GMT)
commit08922f644878c9163ada8df3ef9def89be1d5e90 (patch)
treed29bb6fade704b652cfbe40078eca606a083debb
parent5651d6aaf489d1db48c253cf884b40214e91c2c5 (diff)
downloadlinux-08922f644878c9163ada8df3ef9def89be1d5e90.tar.xz
mtd: devices: m25p80: add support for mmap read request
Certain SPI controllers may provide accelerated hardware interface to read from m25p80 type flash devices in order to provide better read performance. SPI core supports such devices with spi_flash_read() API. Call spi_flash_read(), if supported, to make use of such interface. Signed-off-by: Vignesh R <vigneshr@ti.com> [Brian: add memset()] Signed-off-by: Brian Norris <computersforpeace@gmail.com>
-rw-r--r--drivers/mtd/devices/m25p80.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index c9c3b7f..9d68544 100644
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -131,6 +131,28 @@ static int m25p80_read(struct spi_nor *nor, loff_t from, size_t len,
/* convert the dummy cycles to the number of bytes */
dummy /= 8;
+ if (spi_flash_read_supported(spi)) {
+ struct spi_flash_read_message msg;
+ int ret;
+
+ memset(&msg, 0, sizeof(msg));
+
+ msg.buf = buf;
+ msg.from = from;
+ msg.len = len;
+ msg.read_opcode = nor->read_opcode;
+ msg.addr_width = nor->addr_width;
+ msg.dummy_bytes = dummy;
+ /* TODO: Support other combinations */
+ msg.opcode_nbits = SPI_NBITS_SINGLE;
+ msg.addr_nbits = SPI_NBITS_SINGLE;
+ msg.data_nbits = m25p80_rx_nbits(nor);
+
+ ret = spi_flash_read(spi, &msg);
+ *retlen = msg.retlen;
+ return ret;
+ }
+
spi_message_init(&m);
memset(t, 0, (sizeof t));