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authorRussell King <rmk+kernel@arm.linux.org.uk>2012-01-21 09:33:38 +0000
committerRussell King <rmk+kernel@arm.linux.org.uk>2012-02-18 23:15:32 +0000
commitcae154767a96563d33924872aacfdc63d584f707 (patch)
tree5071f9b5c462bb48b8f6539aeb62664a3e7ab20a /drivers/mfd/ucb1x00-core.c
parentddb1e04a35846b6c5b6039e92555dafaf6ee03d2 (diff)
MFD: ucb1x00-core: use mutexes instead of semaphores
Convert the ucb1x00 driver to use mutexes rather than the depreciated semaphores for exclusive access to the ADC. Acked-by: Jochen Friedrich <jochen@scram.de> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'drivers/mfd/ucb1x00-core.c')
-rw-r--r--drivers/mfd/ucb1x00-core.c15
1 files changed, 7 insertions, 8 deletions
diff --git a/drivers/mfd/ucb1x00-core.c b/drivers/mfd/ucb1x00-core.c
index c2757c11ce7b..7386f822d4cd 100644
--- a/drivers/mfd/ucb1x00-core.c
+++ b/drivers/mfd/ucb1x00-core.c
@@ -27,7 +27,6 @@
#include <linux/mutex.h>
#include <linux/mfd/ucb1x00.h>
#include <linux/gpio.h>
-#include <linux/semaphore.h>
static DEFINE_MUTEX(ucb1x00_mutex);
static LIST_HEAD(ucb1x00_drivers);
@@ -99,7 +98,7 @@ void ucb1x00_io_write(struct ucb1x00 *ucb, unsigned int set, unsigned int clear)
* ucb1x00_enable must have been called to enable the comms
* before using this function.
*
- * This function does not take any semaphores or spinlocks.
+ * This function does not take any mutexes or spinlocks.
*/
unsigned int ucb1x00_io_read(struct ucb1x00 *ucb)
{
@@ -183,7 +182,7 @@ static int ucb1x00_gpio_direction_output(struct gpio_chip *chip, unsigned offset
* Any code wishing to use the ADC converter must call this
* function prior to using it.
*
- * This function takes the ADC semaphore to prevent two or more
+ * This function takes the ADC mutex to prevent two or more
* concurrent uses, and therefore may sleep. As a result, it
* can only be called from process context, not interrupt
* context.
@@ -193,7 +192,7 @@ static int ucb1x00_gpio_direction_output(struct gpio_chip *chip, unsigned offset
*/
void ucb1x00_adc_enable(struct ucb1x00 *ucb)
{
- down(&ucb->adc_sem);
+ mutex_lock(&ucb->adc_mutex);
ucb->adc_cr |= UCB_ADC_ENA;
@@ -215,7 +214,7 @@ void ucb1x00_adc_enable(struct ucb1x00 *ucb)
* complete (2 frames max without sync).
*
* If called for a synchronised ADC conversion, it may sleep
- * with the ADC semaphore held.
+ * with the ADC mutex held.
*/
unsigned int ucb1x00_adc_read(struct ucb1x00 *ucb, int adc_channel, int sync)
{
@@ -243,7 +242,7 @@ unsigned int ucb1x00_adc_read(struct ucb1x00 *ucb, int adc_channel, int sync)
* ucb1x00_adc_disable - disable the ADC converter
* @ucb: UCB1x00 structure describing chip
*
- * Disable the ADC converter and release the ADC semaphore.
+ * Disable the ADC converter and release the ADC mutex.
*/
void ucb1x00_adc_disable(struct ucb1x00 *ucb)
{
@@ -251,7 +250,7 @@ void ucb1x00_adc_disable(struct ucb1x00 *ucb)
ucb1x00_reg_write(ucb, UCB_ADC_CR, ucb->adc_cr);
ucb1x00_disable(ucb);
- up(&ucb->adc_sem);
+ mutex_unlock(&ucb->adc_mutex);
}
/*
@@ -560,7 +559,7 @@ static int ucb1x00_probe(struct mcp *mcp)
spin_lock_init(&ucb->lock);
spin_lock_init(&ucb->io_lock);
- sema_init(&ucb->adc_sem, 1);
+ mutex_init(&ucb->adc_mutex);
ucb->id = id;
ucb->mcp = mcp;