summaryrefslogtreecommitdiff
path: root/drivers/spi/spi-bitbang.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/spi/spi-bitbang.c')
-rw-r--r--drivers/spi/spi-bitbang.c25
1 files changed, 18 insertions, 7 deletions
diff --git a/drivers/spi/spi-bitbang.c b/drivers/spi/spi-bitbang.c
index 8c11355dec23..bd222f6b677d 100644
--- a/drivers/spi/spi-bitbang.c
+++ b/drivers/spi/spi-bitbang.c
@@ -191,7 +191,7 @@ int spi_bitbang_setup(struct spi_device *spi)
bitbang = spi_master_get_devdata(spi->master);
if (!cs) {
- cs = kzalloc(sizeof *cs, GFP_KERNEL);
+ cs = kzalloc(sizeof(*cs), GFP_KERNEL);
if (!cs)
return -ENOMEM;
spi->controller_state = cs;
@@ -258,7 +258,7 @@ static int spi_bitbang_bufs(struct spi_device *spi, struct spi_transfer *t)
static int spi_bitbang_prepare_hardware(struct spi_master *spi)
{
- struct spi_bitbang *bitbang;
+ struct spi_bitbang *bitbang;
unsigned long flags;
bitbang = spi_master_get_devdata(spi);
@@ -273,7 +273,7 @@ static int spi_bitbang_prepare_hardware(struct spi_master *spi)
static int spi_bitbang_transfer_one(struct spi_master *master,
struct spi_message *m)
{
- struct spi_bitbang *bitbang;
+ struct spi_bitbang *bitbang;
unsigned nsecs;
struct spi_transfer *t = NULL;
unsigned cs_change;
@@ -292,7 +292,7 @@ static int spi_bitbang_transfer_one(struct spi_master *master,
cs_change = 1;
status = 0;
- list_for_each_entry (t, &m->transfers, transfer_list) {
+ list_for_each_entry(t, &m->transfers, transfer_list) {
/* override speed or wordsize? */
if (t->speed_hz || t->bits_per_word)
@@ -349,7 +349,8 @@ static int spi_bitbang_transfer_one(struct spi_master *master,
if (t->delay_usecs)
udelay(t->delay_usecs);
- if (cs_change && !list_is_last(&t->transfer_list, &m->transfers)) {
+ if (cs_change &&
+ !list_is_last(&t->transfer_list, &m->transfers)) {
/* sometimes a short mid-message deselect of the chip
* may be needed to terminate a mode or command
*/
@@ -378,7 +379,7 @@ static int spi_bitbang_transfer_one(struct spi_master *master,
static int spi_bitbang_unprepare_hardware(struct spi_master *spi)
{
- struct spi_bitbang *bitbang;
+ struct spi_bitbang *bitbang;
unsigned long flags;
bitbang = spi_master_get_devdata(spi);
@@ -414,10 +415,16 @@ static int spi_bitbang_unprepare_hardware(struct spi_master *spi)
* This routine registers the spi_master, which will process requests in a
* dedicated task, keeping IRQs unblocked most of the time. To stop
* processing those requests, call spi_bitbang_stop().
+ *
+ * On success, this routine will take a reference to master. The caller is
+ * responsible for calling spi_bitbang_stop() to decrement the reference and
+ * spi_master_put() as counterpart of spi_alloc_master() to prevent a memory
+ * leak.
*/
int spi_bitbang_start(struct spi_bitbang *bitbang)
{
struct spi_master *master = bitbang->master;
+ int ret;
if (!master || !bitbang->chipselect)
return -EINVAL;
@@ -449,7 +456,11 @@ int spi_bitbang_start(struct spi_bitbang *bitbang)
/* driver may get busy before register() returns, especially
* if someone registered boardinfo for devices
*/
- return spi_register_master(master);
+ ret = spi_register_master(spi_master_get(master));
+ if (ret)
+ spi_master_put(master);
+
+ return 0;
}
EXPORT_SYMBOL_GPL(spi_bitbang_start);