diff options
Diffstat (limited to 'drivers/spi/spi-bitbang.c')
| -rw-r--r-- | drivers/spi/spi-bitbang.c | 30 |
1 files changed, 19 insertions, 11 deletions
diff --git a/drivers/spi/spi-bitbang.c b/drivers/spi/spi-bitbang.c index 8c11355dec2..dc7d2c2d643 100644 --- a/drivers/spi/spi-bitbang.c +++ b/drivers/spi/spi-bitbang.c @@ -16,7 +16,6 @@ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ -#include <linux/init.h> #include <linux/spinlock.h> #include <linux/workqueue.h> #include <linux/interrupt.h> @@ -191,7 +190,7 @@ 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 +257,7 @@ 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 +272,7 @@ 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 +291,7 @@ 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 +348,8 @@ 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 +378,7 @@ 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 +414,16 @@ 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; @@ -449,18 +455,20 @@ 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); /** * spi_bitbang_stop - stops the task providing spi communication */ -int spi_bitbang_stop(struct spi_bitbang *bitbang) +void spi_bitbang_stop(struct spi_bitbang *bitbang) { spi_unregister_master(bitbang->master); - - return 0; } EXPORT_SYMBOL_GPL(spi_bitbang_stop); |