Commit 8bcf6135 authored by Jim Cromie's avatar Jim Cromie Committed by Linus Torvalds

[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: default avatarJim Cromie <jim.cromie@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 6cad56fd
...@@ -9,6 +9,7 @@ ...@@ -9,6 +9,7 @@
#include <linux/errno.h> #include <linux/errno.h>
#include <linux/kernel.h> #include <linux/kernel.h>
#include <linux/init.h> #include <linux/init.h>
#include <linux/mutex.h>
#include <linux/pci.h> #include <linux/pci.h>
#include <linux/scx200.h> #include <linux/scx200.h>
...@@ -45,7 +46,7 @@ static struct pci_driver scx200_pci_driver = { ...@@ -45,7 +46,7 @@ static struct pci_driver scx200_pci_driver = {
.probe = scx200_probe, .probe = scx200_probe,
}; };
static DEFINE_SPINLOCK(scx200_gpio_config_lock); static DEFINE_MUTEX(scx200_gpio_config_lock);
static void __devinit scx200_init_shadow(void) static void __devinit scx200_init_shadow(void)
{ {
...@@ -95,9 +96,8 @@ static int __devinit scx200_probe(struct pci_dev *pdev, const struct pci_device_ ...@@ -95,9 +96,8 @@ static int __devinit scx200_probe(struct pci_dev *pdev, const struct pci_device_
u32 scx200_gpio_configure(unsigned index, u32 mask, u32 bits) u32 scx200_gpio_configure(unsigned index, u32 mask, u32 bits)
{ {
u32 config, new_config; 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); outl(index, scx200_gpio_base + 0x20);
config = inl(scx200_gpio_base + 0x24); config = inl(scx200_gpio_base + 0x24);
...@@ -105,7 +105,7 @@ u32 scx200_gpio_configure(unsigned index, u32 mask, u32 bits) ...@@ -105,7 +105,7 @@ u32 scx200_gpio_configure(unsigned index, u32 mask, u32 bits)
new_config = (config & mask) | bits; new_config = (config & mask) | bits;
outl(new_config, scx200_gpio_base + 0x24); outl(new_config, scx200_gpio_base + 0x24);
spin_unlock_irqrestore(&scx200_gpio_config_lock, flags); mutex_unlock(&scx200_gpio_config_lock);
return config; return config;
} }
......
...@@ -16,6 +16,7 @@ ...@@ -16,6 +16,7 @@
#include <linux/kernel.h> #include <linux/kernel.h>
#include <linux/init.h> #include <linux/init.h>
#include <linux/ioport.h> #include <linux/ioport.h>
#include <linux/mutex.h>
#include <linux/nsc_gpio.h> #include <linux/nsc_gpio.h>
#include <linux/platform_device.h> #include <linux/platform_device.h>
#include <asm/uaccess.h> #include <asm/uaccess.h>
...@@ -31,7 +32,7 @@ static int major; /* default to dynamic major */ ...@@ -31,7 +32,7 @@ static int major; /* default to dynamic major */
module_param(major, int, 0); module_param(major, int, 0);
MODULE_PARM_DESC(major, "Major device number"); 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 unsigned pc8736x_gpio_base;
static u8 pc8736x_gpio_shadow[4]; static u8 pc8736x_gpio_shadow[4];
...@@ -119,9 +120,8 @@ static inline u32 pc8736x_gpio_configure_fn(unsigned index, u32 mask, u32 bits, ...@@ -119,9 +120,8 @@ static inline u32 pc8736x_gpio_configure_fn(unsigned index, u32 mask, u32 bits,
u32 func_slct) u32 func_slct)
{ {
u32 config, new_config; 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); device_select(SIO_GPIO_UNIT);
select_pin(index); select_pin(index);
...@@ -133,7 +133,7 @@ static inline u32 pc8736x_gpio_configure_fn(unsigned index, u32 mask, u32 bits, ...@@ -133,7 +133,7 @@ static inline u32 pc8736x_gpio_configure_fn(unsigned index, u32 mask, u32 bits,
new_config = (config & mask) | bits; new_config = (config & mask) | bits;
superio_outb(func_slct, new_config); superio_outb(func_slct, new_config);
spin_unlock_irqrestore(&pc8736x_gpio_config_lock, flags); mutex_unlock(&pc8736x_gpio_config_lock);
return config; return config;
} }
......
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