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authorJon Hunter <jonathanh@nvidia.com>2017-11-14 14:43:28 +0000
committerLee Jones <lee.jones@linaro.org>2018-01-08 11:03:34 +0000
commitd501ff903bdd735b215bded10958d8f794ca0339 (patch)
treef1a7188a67697fab4407df5915ae168d08651d1c /drivers/mfd
parent572ff4d560be3784205b224cd67d6715620092d7 (diff)
downloadlinux-d501ff903bdd735b215bded10958d8f794ca0339.tar.bz2
mfd: cros ec: spi: Simplify delay handling between SPI messages
The EC SPI driver prevents SPI transfers being to rapidly by keeping track of the time the last transfer was issued via the 'last_transfer_ns' variable. Previously, if the 'last_transfer_ns' variable was zero, this indicated that no previous transfer had been sent and that no delay was needed. However, the EC SPI driver has been updated to always initialise the 'last_transfer_ns' variable during probe and therefore, it is no longer necessary to test if it is zero. Remove the code that checks if this variable is zero. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Reviewed-by: Brian Norris <briannorris@chromium.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Acked-by: Benson Leung <bleung@chromium.org> Signed-off-by: Lee Jones <lee.jones@linaro.org>
Diffstat (limited to 'drivers/mfd')
-rw-r--r--drivers/mfd/cros_ec_spi.c25
1 files changed, 9 insertions, 16 deletions
diff --git a/drivers/mfd/cros_ec_spi.c b/drivers/mfd/cros_ec_spi.c
index c9714072e224..54cb760342f5 100644
--- a/drivers/mfd/cros_ec_spi.c
+++ b/drivers/mfd/cros_ec_spi.c
@@ -72,8 +72,7 @@
* struct cros_ec_spi - information about a SPI-connected EC
*
* @spi: SPI device we are connected to
- * @last_transfer_ns: time that we last finished a transfer, or 0 if there
- * if no record
+ * @last_transfer_ns: time that we last finished a transfer.
* @start_of_msg_delay: used to set the delay_usecs on the spi_transfer that
* is sent when we want to turn on CS at the start of a transaction.
* @end_of_msg_delay: used to set the delay_usecs on the spi_transfer that
@@ -378,18 +377,15 @@ static int cros_ec_pkt_xfer_spi(struct cros_ec_device *ec_dev,
u8 *rx_buf;
u8 sum;
int ret = 0, final_ret;
+ unsigned long delay;
len = cros_ec_prepare_tx(ec_dev, ec_msg);
dev_dbg(ec_dev->dev, "prepared, len=%d\n", len);
/* If it's too soon to do another transaction, wait */
- if (ec_spi->last_transfer_ns) {
- unsigned long delay; /* The delay completed so far */
-
- delay = ktime_get_ns() - ec_spi->last_transfer_ns;
- if (delay < EC_SPI_RECOVERY_TIME_NS)
- ndelay(EC_SPI_RECOVERY_TIME_NS - delay);
- }
+ delay = ktime_get_ns() - ec_spi->last_transfer_ns;
+ if (delay < EC_SPI_RECOVERY_TIME_NS)
+ ndelay(EC_SPI_RECOVERY_TIME_NS - delay);
rx_buf = kzalloc(len, GFP_KERNEL);
if (!rx_buf)
@@ -510,18 +506,15 @@ static int cros_ec_cmd_xfer_spi(struct cros_ec_device *ec_dev,
u8 *rx_buf;
int sum;
int ret = 0, final_ret;
+ unsigned long delay;
len = cros_ec_prepare_tx(ec_dev, ec_msg);
dev_dbg(ec_dev->dev, "prepared, len=%d\n", len);
/* If it's too soon to do another transaction, wait */
- if (ec_spi->last_transfer_ns) {
- unsigned long delay; /* The delay completed so far */
-
- delay = ktime_get_ns() - ec_spi->last_transfer_ns;
- if (delay < EC_SPI_RECOVERY_TIME_NS)
- ndelay(EC_SPI_RECOVERY_TIME_NS - delay);
- }
+ delay = ktime_get_ns() - ec_spi->last_transfer_ns;
+ if (delay < EC_SPI_RECOVERY_TIME_NS)
+ ndelay(EC_SPI_RECOVERY_TIME_NS - delay);
rx_buf = kzalloc(len, GFP_KERNEL);
if (!rx_buf)