fbdev: Introduce devm_register_framebuffer()

Introduce a device-managed variant of register_framebuffer() which
automatically unregisters the framebuffer on device destruction.
This can simplify the error handling and resource management in drivers.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Helge Deller <deller@gmx.de>

diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c
index 4c4ad0a86a5044dea7b6c89aad242ecc5477a9b9..3c568cff2913e4f625333b31906636b732b280a7 100644 (file)
--- a/drivers/video/fbdev/core/fbmem.c
+++ b/drivers/video/fbdev/core/fbmem.c
@@ -544,6 +544,36 @@ unregister_framebuffer(struct fb_info *fb_info)
 }
 EXPORT_SYMBOL(unregister_framebuffer);
 
+static void devm_unregister_framebuffer(void *data)
+{
+       struct fb_info *info = data;
+
+       unregister_framebuffer(info);
+}
+
+/**
+ *     devm_register_framebuffer - resource-managed frame buffer device registration
+ *     @dev: device the framebuffer belongs to
+ *     @fb_info: frame buffer info structure
+ *
+ *     Registers a frame buffer device @fb_info to device @dev.
+ *
+ *     Returns negative errno on error, or zero for success.
+ *
+ */
+int
+devm_register_framebuffer(struct device *dev, struct fb_info *fb_info)
+{
+       int ret;
+
+       ret = register_framebuffer(fb_info);
+       if (ret)
+               return ret;
+
+       return devm_add_action_or_reset(dev, devm_unregister_framebuffer, fb_info);
+}
+EXPORT_SYMBOL(devm_register_framebuffer);
+
 /**
  *     fb_set_suspend - low level driver signals suspend
  *     @info: framebuffer affected

diff --git a/include/linux/fb.h b/include/linux/fb.h
index db7d97b10964778a1db4606ac2accb703099b095..abf6643ebcafb11c417328bd178494303b4fdb90 100644 (file)
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -601,6 +601,7 @@ extern ssize_t fb_sys_write(struct fb_info *info, const char __user *buf,
 /* fbmem.c */
 extern int register_framebuffer(struct fb_info *fb_info);
 extern void unregister_framebuffer(struct fb_info *fb_info);
+extern int devm_register_framebuffer(struct device *dev, struct fb_info *fb_info);
 extern char* fb_get_buffer_offset(struct fb_info *info, struct fb_pixmap *buf, u32 size);
 extern void fb_pad_unaligned_buffer(u8 *dst, u32 d_pitch, u8 *src, u32 idx,
                                u32 height, u32 shift_high, u32 shift_low, u32 mod);