fbdev: make FB_BACKLIGHT a tristate

BACKLIGHT_CLASS_DEVICE is already tristate, but a dependency FB_BACKLIGHT prevents it from being built as a module. There doesn't seem to be any particularly good reason for this, so switch FB_BACKLIGHT over to tristate.

Signed-off-by Rob Clark <[email protected]>

Tested-by Arnd Bergmann <[email protected]>

---
v2: remove IS_ENABLED() from UABI headers. Userspace doesn't
know the kernel config, so just remove the ifdef guard

 drivers/video/fbdev/Kconfig        | 2 +-
 drivers/video/fbdev/core/fbsysfs.c | 8 ++++----
 include/linux/fb.h                 | 2 +-
 include/uapi/linux/fb.h            | 2 --
 4 files changed, 6 insertions(+), 8 deletions(-)

drivers/video/fbdev/Kconfig +1 -1

index 591a13a59787..146ab2c347f8 100644
@@ -198,7 +198,7 @@ config FB_MACMODES
        default n
 
 config FB_BACKLIGHT
-       bool
+       tristate
        depends on FB
        select BACKLIGHT_LCD_SUPPORT
        select BACKLIGHT_CLASS_DEVICE

drivers/video/fbdev/core/fbsysfs.c +4 -4

index e31a182b42bf..44cca39f2b51 100644
@@ -60,7 +60,7 @@ struct fb_info *framebuffer_alloc(size_t size, struct device *dev)
        info->device = dev;
        info->fbcon_rotate_hint = -1;
 
-#ifdef CONFIG_FB_BACKLIGHT
+#if IS_ENABLED(CONFIG_FB_BACKLIGHT)
        mutex_init(&info->bl_curve_mutex);
 #endif
 

@@ -429,7 +429,7 @@ static ssize_t show_fbstate(struct device *device,
        return snprintf(buf, PAGE_SIZE, "%d\n", fb_info->state);
 }
 
-#ifdef CONFIG_FB_BACKLIGHT
+#if IS_ENABLED(CONFIG_FB_BACKLIGHT)
 static ssize_t store_bl_curve(struct device *device,
                              struct device_attribute *attr,
                              const char *buf, size_t count)

@@ -510,7 +510,7 @@ static struct device_attribute device_attrs[] = {
        __ATTR(stride, S_IRUGO, show_stride, NULL),
        __ATTR(rotate, S_IRUGO|S_IWUSR, show_rotate, store_rotate),
        __ATTR(state, S_IRUGO|S_IWUSR, show_fbstate, store_fbstate),
-#ifdef CONFIG_FB_BACKLIGHT
+#if IS_ENABLED(CONFIG_FB_BACKLIGHT)
        __ATTR(bl_curve, S_IRUGO|S_IWUSR, show_bl_curve, store_bl_curve),
 #endif
 };

@@ -551,7 +551,7 @@ void fb_cleanup_device(struct fb_info *fb_info)
        }
 }
 
-#ifdef CONFIG_FB_BACKLIGHT
+#if IS_ENABLED(CONFIG_FB_BACKLIGHT)
 /* This function generates a linear backlight curve
  *
  *     0: off

include/linux/fb.h +1 -1

index a3cab6dc9b44..7cdd31a69719 100644
@@ -485,7 +485,7 @@ struct fb_info {
        struct list_head modelist;      /* mode list */
        struct fb_videomode *mode;      /* current mode */
 
-#ifdef CONFIG_FB_BACKLIGHT
+#if IS_ENABLED(CONFIG_FB_BACKLIGHT)
        /* assigned backlight device */
        /* set before framebuffer registration,
           remove after unregister */

include/uapi/linux/fb.h +0 -3

index 6cd9b198b7c6..b6aac7ee1f67 100644
@@ -393,11 +393,9 @@ struct fb_cursor {
        struct fb_image image;  /* Cursor image */
 };
 
-#ifdef CONFIG_FB_BACKLIGHT
 /* Settings for the generic backlight code */
 #define FB_BACKLIGHT_LEVELS    128
 #define FB_BACKLIGHT_MAX       0xFF
-#endif
 
 
 #endif /* _UAPI_LINUX_FB_H */
--

2.17.2

Quoted 8 lines · Rob Clark

BACKLIGHT_CLASS_DEVICE is already tristate, but a dependency FB_BACKLIGHT prevents it from being built as a module. There doesn't seem to be any particularly good reason for this, so switch FB_BACKLIGHT over to tristate.

Signed-off-by Rob Clark <[email protected]>

Tested-by Arnd Bergmann <[email protected]>

bump