[PATCH] platform/x86: apple-gmux: Use guard(mutex) to simplify the code

[Thorsten Blum]

Use guard(mutex) and remove the manual mutex_unlock() calls. Return
several results directly and drop the now-unused local variables.

Signed-off-by: Thorsten Blum <blum@xxxxxxxxxx>
---
 drivers/platform/x86/apple-gmux.c | 48 +++++++++----------------------
 1 file changed, 14 insertions(+), 34 deletions(-)

diff --git a/drivers/platform/x86/apple-gmux.c b/drivers/platform/x86/apple-gmux.c
index 9c728ac4e045..6c7790012011 100644
--- a/drivers/platform/x86/apple-gmux.c
+++ b/drivers/platform/x86/apple-gmux.c
@@ -169,41 +169,32 @@ static int gmux_index_wait_complete(struct apple_gmux_data *gmux_data)
 
 static u8 gmux_index_read8(struct apple_gmux_data *gmux_data, int port)
 {
-	u8 val;
-
-	mutex_lock(&gmux_data->index_lock);
+	guard(mutex)(&gmux_data->index_lock);
 	gmux_index_wait_ready(gmux_data);
 	outb((port & 0xff), gmux_data->iostart + GMUX_PORT_READ);
 	gmux_index_wait_complete(gmux_data);
-	val = inb(gmux_data->iostart + GMUX_PORT_VALUE);
-	mutex_unlock(&gmux_data->index_lock);
 
-	return val;
+	return inb(gmux_data->iostart + GMUX_PORT_VALUE);
 }
 
 static void gmux_index_write8(struct apple_gmux_data *gmux_data, int port,
 			      u8 val)
 {
-	mutex_lock(&gmux_data->index_lock);
+	guard(mutex)(&gmux_data->index_lock);
 	outb(val, gmux_data->iostart + GMUX_PORT_VALUE);
 	gmux_index_wait_ready(gmux_data);
 	outb(port & 0xff, gmux_data->iostart + GMUX_PORT_WRITE);
 	gmux_index_wait_complete(gmux_data);
-	mutex_unlock(&gmux_data->index_lock);
 }
 
 static u32 gmux_index_read32(struct apple_gmux_data *gmux_data, int port)
 {
-	u32 val;
-
-	mutex_lock(&gmux_data->index_lock);
+	guard(mutex)(&gmux_data->index_lock);
 	gmux_index_wait_ready(gmux_data);
 	outb((port & 0xff), gmux_data->iostart + GMUX_PORT_READ);
 	gmux_index_wait_complete(gmux_data);
-	val = inl(gmux_data->iostart + GMUX_PORT_VALUE);
-	mutex_unlock(&gmux_data->index_lock);
 
-	return val;
+	return inl(gmux_data->iostart + GMUX_PORT_VALUE);
 }
 
 static void gmux_index_write32(struct apple_gmux_data *gmux_data, int port,
@@ -212,7 +203,7 @@ static void gmux_index_write32(struct apple_gmux_data *gmux_data, int port,
 	int i;
 	u8 tmpval;
 
-	mutex_lock(&gmux_data->index_lock);
+	guard(mutex)(&gmux_data->index_lock);
 
 	for (i = 0; i < 4; i++) {
 		tmpval = (val >> (i * 8)) & 0xff;
@@ -222,7 +213,6 @@ static void gmux_index_write32(struct apple_gmux_data *gmux_data, int port,
 	gmux_index_wait_ready(gmux_data);
 	outb(port & 0xff, gmux_data->iostart + GMUX_PORT_WRITE);
 	gmux_index_wait_complete(gmux_data);
-	mutex_unlock(&gmux_data->index_lock);
 }
 
 static int gmux_mmio_wait(struct apple_gmux_data *gmux_data)
@@ -241,24 +231,20 @@ static int gmux_mmio_wait(struct apple_gmux_data *gmux_data)
 
 static u8 gmux_mmio_read8(struct apple_gmux_data *gmux_data, int port)
 {
-	u8 val;
-
-	mutex_lock(&gmux_data->index_lock);
+	guard(mutex)(&gmux_data->index_lock);
 	gmux_mmio_wait(gmux_data);
 	iowrite8((port & 0xff), gmux_data->iomem_base + GMUX_MMIO_PORT_SELECT);
-	iowrite8(GMUX_MMIO_READ | sizeof(val),
+	iowrite8(GMUX_MMIO_READ | sizeof(u8),
 		gmux_data->iomem_base + GMUX_MMIO_COMMAND_SEND);
 	gmux_mmio_wait(gmux_data);
-	val = ioread8(gmux_data->iomem_base);
-	mutex_unlock(&gmux_data->index_lock);
 
-	return val;
+	return ioread8(gmux_data->iomem_base);
 }
 
 static void gmux_mmio_write8(struct apple_gmux_data *gmux_data, int port,
 			      u8 val)
 {
-	mutex_lock(&gmux_data->index_lock);
+	guard(mutex)(&gmux_data->index_lock);
 	gmux_mmio_wait(gmux_data);
 	iowrite8(val, gmux_data->iomem_base);
 
@@ -267,35 +253,29 @@ static void gmux_mmio_write8(struct apple_gmux_data *gmux_data, int port,
 		gmux_data->iomem_base + GMUX_MMIO_COMMAND_SEND);
 
 	gmux_mmio_wait(gmux_data);
-	mutex_unlock(&gmux_data->index_lock);
 }
 
 static u32 gmux_mmio_read32(struct apple_gmux_data *gmux_data, int port)
 {
-	u32 val;
-
-	mutex_lock(&gmux_data->index_lock);
+	guard(mutex)(&gmux_data->index_lock);
 	gmux_mmio_wait(gmux_data);
 	iowrite8((port & 0xff), gmux_data->iomem_base + GMUX_MMIO_PORT_SELECT);
-	iowrite8(GMUX_MMIO_READ | sizeof(val),
+	iowrite8(GMUX_MMIO_READ | sizeof(u32),
 		gmux_data->iomem_base + GMUX_MMIO_COMMAND_SEND);
 	gmux_mmio_wait(gmux_data);
-	val = ioread32be(gmux_data->iomem_base);
-	mutex_unlock(&gmux_data->index_lock);
 
-	return val;
+	return ioread32be(gmux_data->iomem_base);
 }
 
 static void gmux_mmio_write32(struct apple_gmux_data *gmux_data, int port,
 			       u32 val)
 {
-	mutex_lock(&gmux_data->index_lock);
+	guard(mutex)(&gmux_data->index_lock);
 	iowrite32be(val, gmux_data->iomem_base);
 	iowrite8(port & 0xff, gmux_data->iomem_base + GMUX_MMIO_PORT_SELECT);
 	iowrite8(GMUX_MMIO_WRITE | sizeof(val),
 		gmux_data->iomem_base + GMUX_MMIO_COMMAND_SEND);
 	gmux_mmio_wait(gmux_data);
-	mutex_unlock(&gmux_data->index_lock);
 }
 
 static u8 gmux_read8(struct apple_gmux_data *gmux_data, int port)