diff options
Diffstat (limited to 'drivers/video/backlight/apple_bl.c')
| -rw-r--r-- | drivers/video/backlight/apple_bl.c | 48 |
1 files changed, 32 insertions, 16 deletions
diff --git a/drivers/video/backlight/apple_bl.c b/drivers/video/backlight/apple_bl.c index be98d152b7f..d8432967668 100644 --- a/drivers/video/backlight/apple_bl.c +++ b/drivers/video/backlight/apple_bl.c @@ -16,6 +16,8 @@ * get at the firmware code in order to figure out what it's actually doing. */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + #include <linux/module.h> #include <linux/kernel.h> #include <linux/init.h> @@ -24,6 +26,8 @@ #include <linux/io.h> #include <linux/pci.h> #include <linux/acpi.h> +#include <linux/atomic.h> +#include <linux/apple_bl.h> static struct backlight_device *apple_backlight_device; @@ -38,8 +42,6 @@ struct hw_data { static const struct hw_data *hw_data; -#define DRIVER "apple_backlight: " - /* Module parameters. */ static int debug; module_param_named(debug, debug, int, 0644); @@ -59,8 +61,7 @@ static int intel_chipset_send_intensity(struct backlight_device *bd) int intensity = bd->props.brightness; if (debug) - printk(KERN_DEBUG DRIVER "setting brightness to %d\n", - intensity); + pr_debug("setting brightness to %d\n", intensity); intel_chipset_set_brightness(intensity); return 0; @@ -75,8 +76,7 @@ static int intel_chipset_get_intensity(struct backlight_device *bd) intensity = inb(0xb3) >> 4; if (debug) - printk(KERN_DEBUG DRIVER "read brightness of %d\n", - intensity); + pr_debug("read brightness of %d\n", intensity); return intensity; } @@ -106,8 +106,7 @@ static int nvidia_chipset_send_intensity(struct backlight_device *bd) int intensity = bd->props.brightness; if (debug) - printk(KERN_DEBUG DRIVER "setting brightness to %d\n", - intensity); + pr_debug("setting brightness to %d\n", intensity); nvidia_chipset_set_brightness(intensity); return 0; @@ -122,8 +121,7 @@ static int nvidia_chipset_get_intensity(struct backlight_device *bd) intensity = inb(0x52f) >> 4; if (debug) - printk(KERN_DEBUG DRIVER "read brightness of %d\n", - intensity); + pr_debug("read brightness of %d\n", intensity); return intensity; } @@ -139,7 +137,7 @@ static const struct hw_data nvidia_chipset_data = { .set_brightness = nvidia_chipset_set_brightness, }; -static int __devinit apple_bl_add(struct acpi_device *dev) +static int apple_bl_add(struct acpi_device *dev) { struct backlight_properties props; struct pci_dev *host; @@ -148,7 +146,7 @@ static int __devinit apple_bl_add(struct acpi_device *dev) host = pci_get_bus_and_slot(0, 0); if (!host) { - printk(KERN_ERR DRIVER "unable to find PCI host\n"); + pr_err("unable to find PCI host\n"); return -ENODEV; } @@ -160,7 +158,7 @@ static int __devinit apple_bl_add(struct acpi_device *dev) pci_dev_put(host); if (!hw_data) { - printk(KERN_ERR DRIVER "unknown hardware\n"); + pr_err("unknown hardware\n"); return -ENODEV; } @@ -198,7 +196,7 @@ static int __devinit apple_bl_add(struct acpi_device *dev) return 0; } -static int __devexit apple_bl_remove(struct acpi_device *dev, int type) +static int apple_bl_remove(struct acpi_device *dev) { backlight_device_unregister(apple_backlight_device); @@ -221,14 +219,32 @@ static struct acpi_driver apple_bl_driver = { }, }; +static atomic_t apple_bl_registered = ATOMIC_INIT(0); + +int apple_bl_register(void) +{ + if (atomic_xchg(&apple_bl_registered, 1) == 0) + return acpi_bus_register_driver(&apple_bl_driver); + + return 0; +} +EXPORT_SYMBOL_GPL(apple_bl_register); + +void apple_bl_unregister(void) +{ + if (atomic_xchg(&apple_bl_registered, 0) == 1) + acpi_bus_unregister_driver(&apple_bl_driver); +} +EXPORT_SYMBOL_GPL(apple_bl_unregister); + static int __init apple_bl_init(void) { - return acpi_bus_register_driver(&apple_bl_driver); + return apple_bl_register(); } static void __exit apple_bl_exit(void) { - acpi_bus_unregister_driver(&apple_bl_driver); + apple_bl_unregister(); } module_init(apple_bl_init); |