From: Andrey Pronin <apro...@chromium.org>
Some devices may need CS to be deasserted for some time
between transactions. Added a new capability to guarantee
a delay between SPI transactions for the device.
Signed-off-by: Andrey Pronin <apro...@chromium.org>
---
drivers/spi/spi.c | 3 +++
include/linux/spi/spi.h | 4 ++++
2 files changed, 7 insertions(+)
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index c51c864..639c7bd 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -971,6 +971,9 @@ static int spi_transfer_one_message(struct spi_master
*master,
spi_reset_cs_wake_timer(msg->spi);
}
+ if (msg->spi->xfer_delay)
+ mdelay(msg->spi->xfer_delay);
+
spi_set_cs(msg->spi, true);
SPI_STATISTICS_INCREMENT_FIELD(statm, messages);
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index 4b06ba6..4b1aa13 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -137,6 +137,8 @@ void spi_statistics_add_transfer_stats(struct
spi_statistics *stats,
* @cs_wake_timer: Timer measuring the delay before the device goes to
* sleep after the last SPI transaction.
*
+ * @xfer_delay: Delay between SPI transactions (msec).
+ *
* @statistics: statistics for the spi_device
*
* A @spi_device is used to interchange data between an SPI slave
@@ -183,6 +185,8 @@ struct spi_device {
bool cs_wake_needed;
struct timer_list cs_wake_timer;
+ u32 xfer_delay;
+
/* the statistics */
struct spi_statistics statistics;
--
2.6.6
