Add functions to allow other modules to enable or disable apple_bl. This will be used by the gmux driver to disable apple_bl when the gmux is present, as it is a better and more reliable option for brightness control.
Signed-off-by: Seth Forshee <[email protected]> --- drivers/video/backlight/apple_bl.c | 23 +++++++++++++++++++++-- include/linux/apple_bl.h | 11 +++++++++++ 2 files changed, 32 insertions(+), 2 deletions(-) create mode 100644 include/linux/apple_bl.h diff --git a/drivers/video/backlight/apple_bl.c b/drivers/video/backlight/apple_bl.c index be98d15..87332ce 100644 --- a/drivers/video/backlight/apple_bl.c +++ b/drivers/video/backlight/apple_bl.c @@ -24,6 +24,7 @@ #include <linux/io.h> #include <linux/pci.h> #include <linux/acpi.h> +#include <linux/atomic.h> static struct backlight_device *apple_backlight_device; @@ -221,14 +222,32 @@ static struct acpi_driver apple_bl_driver = { }, }; +atomic_t apple_bl_register_count = ATOMIC_INIT(0); + +int apple_bl_register(void) +{ + if (atomic_xchg(&apple_bl_register_count, 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_register_count, 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); diff --git a/include/linux/apple_bl.h b/include/linux/apple_bl.h new file mode 100644 index 0000000..5c86ae5 --- /dev/null +++ b/include/linux/apple_bl.h @@ -0,0 +1,11 @@ +/* + * apple_bl exported symbols + */ + +#ifndef _LINUX_APPLE_BL_H +#define _LINUX_APPLE_BL_H + +extern int apple_bl_register(void); +extern void apple_bl_unregister(void); + +#endif -- 1.7.9.1 -- To unsubscribe from this list: send the line "unsubscribe platform-driver-x86" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
