summaryrefslogtreecommitdiff
path: root/drivers/spi/spi-bitbang.c
diff options
context:
space:
mode:
authorPelle Nilsson <per.nilsson@xelmo.com>2015-04-14 15:40:17 +0200
committerMark Brown <broonie@kernel.org>2015-04-18 12:01:03 +0100
commit7d0ec8b6f40b356f780b79de63eeafd6b907d68c (patch)
tree669ce3a25a14487c4dd0bb08839719e89245ca9c /drivers/spi/spi-bitbang.c
parentc517d838eb7d07bbe9507871fab3931deccff539 (diff)
spi: bitbang: Make setup_transfer() callback optional
Some controller drivers have no need of this callback (spi-altera even causes a NULL pointer dereference because it doesn't register the callback, falsely assuming that it is already optional). Fixes: 30af9b558a56 ("spi/bitbang: Drop empty setup() functions") Signed-off-by: Pelle Nilsson <per.nilsson@xelmo.com> Reviewed-by: Ezequiel Garcia <ezequiel.garcia@vanguardiasur.com.ar> Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi/spi-bitbang.c')
-rw-r--r--drivers/spi/spi-bitbang.c17
1 files changed, 10 insertions, 7 deletions
diff --git a/drivers/spi/spi-bitbang.c b/drivers/spi/spi-bitbang.c
index 5ef6638d5e8a..840a4984d365 100644
--- a/drivers/spi/spi-bitbang.c
+++ b/drivers/spi/spi-bitbang.c
@@ -180,7 +180,6 @@ int spi_bitbang_setup(struct spi_device *spi)
{
struct spi_bitbang_cs *cs = spi->controller_state;
struct spi_bitbang *bitbang;
- int retval;
unsigned long flags;
bitbang = spi_master_get_devdata(spi->master);
@@ -197,9 +196,11 @@ int spi_bitbang_setup(struct spi_device *spi)
if (!cs->txrx_word)
return -EINVAL;
- retval = bitbang->setup_transfer(spi, NULL);
- if (retval < 0)
- return retval;
+ if (bitbang->setup_transfer) {
+ int retval = bitbang->setup_transfer(spi, NULL);
+ if (retval < 0)
+ return retval;
+ }
dev_dbg(&spi->dev, "%s, %u nsec/bit\n", __func__, 2 * cs->nsecs);
@@ -295,9 +296,11 @@ static int spi_bitbang_transfer_one(struct spi_master *master,
/* init (-1) or override (1) transfer params */
if (do_setup != 0) {
- status = bitbang->setup_transfer(spi, t);
- if (status < 0)
- break;
+ if (bitbang->setup_transfer) {
+ status = bitbang->setup_transfer(spi, t);
+ if (status < 0)
+ break;
+ }
if (do_setup == -1)
do_setup = 0;
}