Merge remote-tracking branches 'asoc/topic/ad1836', 'asoc/topic/ad193x', 'asoc/topic...

[firefly-linux-kernel-4.4.55.git] / drivers / spi / spi-bitbang.c

diff --git a/drivers/spi/spi-bitbang.c b/drivers/spi/spi-bitbang.c
index 8c11355dec233595a04a33877f832084af933168..bd222f6b677d0c775dbd608a66356554adefa660 100644 (file)
--- 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);