[PATCH] chardev: GPIO for SCx200 & PC-8736x: replace spinlocks w mutexes

Replace spinlocks guarding gpio config ops with mutexes.  This is a me-too
patch, and is justifiable insofar as mutexes have stricter semantics and
better debugging support, so are preferred where they are applicable.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/i386/kernel/scx200.c

@@ -9,6 +9,7 @@
 #include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
+#include <linux/mutex.h>
 #include <linux/pci.h>
 
 #include <linux/scx200.h>
@@ -45,7 +46,7 @@ static struct pci_driver scx200_pci_driver = {
 	.probe = scx200_probe,
 };
 
-static DEFINE_SPINLOCK(scx200_gpio_config_lock);
+static DEFINE_MUTEX(scx200_gpio_config_lock);
 
 static void __devinit scx200_init_shadow(void)
 {
@@ -95,17 +96,16 @@ static int __devinit scx200_probe(struct pci_dev *pdev, const struct pci_device_
 u32 scx200_gpio_configure(unsigned index, u32 mask, u32 bits)
 {
 	u32 config, new_config;
-	unsigned long flags;
 
-	spin_lock_irqsave(&scx200_gpio_config_lock, flags);
+	mutex_lock(&scx200_gpio_config_lock);
 
 	outl(index, scx200_gpio_base + 0x20);
 	config = inl(scx200_gpio_base + 0x24);
 
 	new_config = (config & mask) | bits;
 	outl(new_config, scx200_gpio_base + 0x24);
 
-	spin_unlock_irqrestore(&scx200_gpio_config_lock, flags);
+	mutex_unlock(&scx200_gpio_config_lock);
 
 	return config;
 }

drivers/char/pc8736x_gpio.c

@@ -16,6 +16,7 @@
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/ioport.h>
+#include <linux/mutex.h>
 #include <linux/nsc_gpio.h>
 #include <linux/platform_device.h>
 #include <asm/uaccess.h>
@@ -31,7 +32,7 @@ static int major;		/* default to dynamic major */
 module_param(major, int, 0);
 MODULE_PARM_DESC(major, "Major device number");
 
-static DEFINE_SPINLOCK(pc8736x_gpio_config_lock);
+static DEFINE_MUTEX(pc8736x_gpio_config_lock);
 static unsigned pc8736x_gpio_base;
 static u8 pc8736x_gpio_shadow[4];
 
@@ -119,9 +120,8 @@ static inline u32 pc8736x_gpio_configure_fn(unsigned index, u32 mask, u32 bits,
 					    u32 func_slct)
 {
 	u32 config, new_config;
-	unsigned long flags;
 
-	spin_lock_irqsave(&pc8736x_gpio_config_lock, flags);
+	mutex_lock(&pc8736x_gpio_config_lock);
 
 	device_select(SIO_GPIO_UNIT);
 	select_pin(index);
@@ -133,7 +133,7 @@ static inline u32 pc8736x_gpio_configure_fn(unsigned index, u32 mask, u32 bits,
 	new_config = (config & mask) | bits;
 	superio_outb(func_slct, new_config);
 
-	spin_unlock_irqrestore(&pc8736x_gpio_config_lock, flags);
+	mutex_unlock(&pc8736x_gpio_config_lock);
 
 	return config;
 }