Commit 6acc369a authored by Matthias Kaehlcke's avatar Matthias Kaehlcke Committed by Linus Torvalds
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use mutex instead of semaphore in hdaps driver



The hdaps driver uses a semaphore as mutex.  Use the mutex API instead of the
(binary) semaphore.

Signed-off-by: default avatarMatthias Kaehlcke <matthias.kaehlcke@gmail.com>
Cc: Robert Love <rlove@rlove.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d081d470
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+20 −18
Original line number Diff line number Diff line
@@ -30,10 +30,12 @@
#include <linux/platform_device.h>
#include <linux/input.h>
#include <linux/kernel.h>
#include <linux/mutex.h>
#include <linux/module.h>
#include <linux/timer.h>
#include <linux/dmi.h>
#include <linux/jiffies.h>

#include <asm/io.h>

#define HDAPS_LOW_PORT		0x1600	/* first port used by hdaps */
@@ -71,10 +73,10 @@ static u8 km_activity;
static int rest_x;
static int rest_y;

static DECLARE_MUTEX(hdaps_sem);
static DEFINE_MUTEX(hdaps_mtx);

/*
 * __get_latch - Get the value from a given port.  Callers must hold hdaps_sem.
 * __get_latch - Get the value from a given port.  Callers must hold hdaps_mtx.
 */
static inline u8 __get_latch(u16 port)
{
@@ -83,7 +85,7 @@ static inline u8 __get_latch(u16 port)

/*
 * __check_latch - Check a port latch for a given value.  Returns zero if the
 * port contains the given value.  Callers must hold hdaps_sem.
 * port contains the given value.  Callers must hold hdaps_mtx.
 */
static inline int __check_latch(u16 port, u8 val)
{
@@ -94,7 +96,7 @@ static inline int __check_latch(u16 port, u8 val)

/*
 * __wait_latch - Wait up to 100us for a port latch to get a certain value,
 * returning zero if the value is obtained.  Callers must hold hdaps_sem.
 * returning zero if the value is obtained.  Callers must hold hdaps_mtx.
 */
static int __wait_latch(u16 port, u8 val)
{
@@ -111,7 +113,7 @@ static int __wait_latch(u16 port, u8 val)

/*
 * __device_refresh - request a refresh from the accelerometer.  Does not wait
 * for refresh to complete.  Callers must hold hdaps_sem.
 * for refresh to complete.  Callers must hold hdaps_mtx.
 */
static void __device_refresh(void)
{
@@ -125,7 +127,7 @@ static void __device_refresh(void)
/*
 * __device_refresh_sync - request a synchronous refresh from the
 * accelerometer.  We wait for the refresh to complete.  Returns zero if
 * successful and nonzero on error.  Callers must hold hdaps_sem.
 * successful and nonzero on error.  Callers must hold hdaps_mtx.
 */
static int __device_refresh_sync(void)
{
@@ -135,7 +137,7 @@ static int __device_refresh_sync(void)

/*
 * __device_complete - indicate to the accelerometer that we are done reading
 * data, and then initiate an async refresh.  Callers must hold hdaps_sem.
 * data, and then initiate an async refresh.  Callers must hold hdaps_mtx.
 */
static inline void __device_complete(void)
{
@@ -153,7 +155,7 @@ static int hdaps_readb_one(unsigned int port, u8 *val)
{
	int ret;

	down(&hdaps_sem);
	mutex_lock(&hdaps_mtx);

	/* do a sync refresh -- we need to be sure that we read fresh data */
	ret = __device_refresh_sync();
@@ -164,7 +166,7 @@ static int hdaps_readb_one(unsigned int port, u8 *val)
	__device_complete();

out:
	up(&hdaps_sem);
	mutex_unlock(&hdaps_mtx);
	return ret;
}

@@ -199,9 +201,9 @@ static int hdaps_read_pair(unsigned int port1, unsigned int port2,
{
	int ret;

	down(&hdaps_sem);
	mutex_lock(&hdaps_mtx);
	ret = __hdaps_read_pair(port1, port2, val1, val2);
	up(&hdaps_sem);
	mutex_unlock(&hdaps_mtx);

	return ret;
}
@@ -214,7 +216,7 @@ static int hdaps_device_init(void)
{
	int total, ret = -ENXIO;

	down(&hdaps_sem);
	mutex_lock(&hdaps_mtx);

	outb(0x13, 0x1610);
	outb(0x01, 0x161f);
@@ -280,7 +282,7 @@ static int hdaps_device_init(void)
	}

out:
	up(&hdaps_sem);
	mutex_unlock(&hdaps_mtx);
	return ret;
}

@@ -314,7 +316,7 @@ static struct platform_driver hdaps_driver = {
};

/*
 * hdaps_calibrate - Set our "resting" values.  Callers must hold hdaps_sem.
 * hdaps_calibrate - Set our "resting" values.  Callers must hold hdaps_mtx.
 */
static void hdaps_calibrate(void)
{
@@ -326,7 +328,7 @@ static void hdaps_mousedev_poll(unsigned long unused)
	int x, y;

	/* Cannot sleep.  Try nonblockingly.  If we fail, try again later. */
	if (down_trylock(&hdaps_sem)) {
	if (mutex_trylock(&hdaps_mtx)) {
		mod_timer(&hdaps_timer,jiffies + HDAPS_POLL_PERIOD);
		return;
	}
@@ -341,7 +343,7 @@ static void hdaps_mousedev_poll(unsigned long unused)
	mod_timer(&hdaps_timer, jiffies + HDAPS_POLL_PERIOD);

out:
	up(&hdaps_sem);
	mutex_unlock(&hdaps_mtx);
}


@@ -421,9 +423,9 @@ static ssize_t hdaps_calibrate_store(struct device *dev,
				     struct device_attribute *attr,
				     const char *buf, size_t count)
{
	down(&hdaps_sem);
	mutex_lock(&hdaps_mtx);
	hdaps_calibrate();
	up(&hdaps_sem);
	mutex_unlock(&hdaps_mtx);

	return count;
}