[LINUX PATCH 1/2] mtd: Added dummy entry in the spi_transfer structure.

P L Sai Krishna lakshmi.sai.krishna.potthuri at xilinx.com
Mon Mar 21 05:20:08 PDT 2016


This patch does following things.
1. Added dummy entry in the spi_transfer structure.
2. Assigned dummy cycles to dummy member in the transfer
structure during read operation.

Signed-off-by: P L Sai Krishna <lakshmis at xilinx.com>
---
 drivers/mtd/devices/m25p80.c | 1 +
 include/linux/spi/spi.h      | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index c9c3b7f..7c9fac9 100644
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -139,6 +139,7 @@ static int m25p80_read(struct spi_nor *nor, loff_t from, size_t len,
 
 	t[0].tx_buf = flash->command;
 	t[0].len = m25p_cmdsz(nor) + dummy;
+	t[0].dummy = nor->read_dummy;
 	spi_message_add_tail(&t[0], &m);
 
 	t[1].rx_buf = buf;
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index 857a9a1..3f93526 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -664,6 +664,7 @@ extern void spi_res_release(struct spi_master *master,
  * @len: size of rx and tx buffers (in bytes)
  * @speed_hz: Select a speed other than the device default for this
  *      transfer. If 0 the default (from @spi_device) is used.
+ * @dummy: number of dummy cycles.
  * @bits_per_word: select a bits_per_word other than the device default
  *      for this transfer. If 0 the default (from @spi_device) is used.
  * @cs_change: affects chipselect after this transfer completes
@@ -752,6 +753,7 @@ struct spi_transfer {
 	u8		bits_per_word;
 	u16		delay_usecs;
 	u32		speed_hz;
+	u32		dummy;
 
 	struct list_head transfer_list;
 };
-- 
2.1.2




More information about the linux-arm-kernel mailing list