drm/fb_helper: Create wrappers for blit, copyarea and fillrect funcs

drm drivers that emulate fbdev populate their fb_fillrect, fb_copyarea
and fb_imageblit fb_ops with the help of cfb_* or sys_* fbdev core
helper functions.

Create drm_fb_helper functions that wrap around these calls.

This is part of an effort to prevent drm drivers from calling fbdev
functions directly, in order to make fbdev emulation a top level drm
option.

v3:
- Fixed kerneldoc errors

v2:
- Added kerneldocs
- Follow the drm way of aligning of arguments in func definitions
- Remove unnecessary checks for non NULL fb_info
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/Kconfig

@@ -38,6 +38,12 @@ config DRM_KMS_FB_HELPER
 	select FRAMEBUFFER_CONSOLE if !EXPERT
 	select FRAMEBUFFER_CONSOLE_DETECT_PRIMARY if FRAMEBUFFER_CONSOLE
 	select FB_SYS_FOPS
+	select FB_SYS_FILLRECT
+	select FB_SYS_COPYAREA
+	select FB_SYS_IMAGEBLIT
+	select FB_CFB_FILLRECT
+	select FB_CFB_COPYAREA
+	select FB_CFB_IMAGEBLIT
 	help
 	  FBDEV helpers for KMS drivers.
 

drivers/gpu/drm/drm_fb_helper.c

@@ -793,6 +793,90 @@ ssize_t drm_fb_helper_sys_write(struct fb_info *info, const char __user *buf,
 }
 EXPORT_SYMBOL(drm_fb_helper_sys_write);
 
+/**
+ * drm_fb_helper_sys_fillrect - wrapper around sys_fillrect
+ * @info: fbdev registered by the helper
+ * @rect: info about rectangle to fill
+ *
+ * A wrapper around sys_fillrect implemented by fbdev core
+ */
+void drm_fb_helper_sys_fillrect(struct fb_info *info,
+				const struct fb_fillrect *rect)
+{
+	sys_fillrect(info, rect);
+}
+EXPORT_SYMBOL(drm_fb_helper_sys_fillrect);
+
+/**
+ * drm_fb_helper_sys_copyarea - wrapper around sys_copyarea
+ * @info: fbdev registered by the helper
+ * @area: info about area to copy
+ *
+ * A wrapper around sys_copyarea implemented by fbdev core
+ */
+void drm_fb_helper_sys_copyarea(struct fb_info *info,
+				const struct fb_copyarea *area)
+{
+	sys_copyarea(info, area);
+}
+EXPORT_SYMBOL(drm_fb_helper_sys_copyarea);
+
+/**
+ * drm_fb_helper_sys_imageblit - wrapper around sys_imageblit
+ * @info: fbdev registered by the helper
+ * @image: info about image to blit
+ *
+ * A wrapper around sys_imageblit implemented by fbdev core
+ */
+void drm_fb_helper_sys_imageblit(struct fb_info *info,
+				 const struct fb_image *image)
+{
+	sys_imageblit(info, image);
+}
+EXPORT_SYMBOL(drm_fb_helper_sys_imageblit);
+
+/**
+ * drm_fb_helper_cfb_fillrect - wrapper around cfb_fillrect
+ * @info: fbdev registered by the helper
+ * @rect: info about rectangle to fill
+ *
+ * A wrapper around cfb_imageblit implemented by fbdev core
+ */
+void drm_fb_helper_cfb_fillrect(struct fb_info *info,
+				const struct fb_fillrect *rect)
+{
+	cfb_fillrect(info, rect);
+}
+EXPORT_SYMBOL(drm_fb_helper_cfb_fillrect);
+
+/**
+ * drm_fb_helper_cfb_copyarea - wrapper around cfb_copyarea
+ * @info: fbdev registered by the helper
+ * @area: info about area to copy
+ *
+ * A wrapper around cfb_copyarea implemented by fbdev core
+ */
+void drm_fb_helper_cfb_copyarea(struct fb_info *info,
+				const struct fb_copyarea *area)
+{
+	cfb_copyarea(info, area);
+}
+EXPORT_SYMBOL(drm_fb_helper_cfb_copyarea);
+
+/**
+ * drm_fb_helper_cfb_imageblit - wrapper around cfb_imageblit
+ * @info: fbdev registered by the helper
+ * @image: info about image to blit
+ *
+ * A wrapper around cfb_imageblit implemented by fbdev core
+ */
+void drm_fb_helper_cfb_imageblit(struct fb_info *info,
+				 const struct fb_image *image)
+{
+	cfb_imageblit(info, image);
+}
+EXPORT_SYMBOL(drm_fb_helper_cfb_imageblit);
+
 static int setcolreg(struct drm_crtc *crtc, u16 red, u16 green,
 		     u16 blue, u16 regno, struct fb_info *info)
 {

include/drm/drm_fb_helper.h

@@ -152,6 +152,20 @@ ssize_t drm_fb_helper_sys_read(struct fb_info *info, char __user *buf,
 ssize_t drm_fb_helper_sys_write(struct fb_info *info, const char __user *buf,
 				size_t count, loff_t *ppos);
 
+void drm_fb_helper_sys_fillrect(struct fb_info *info,
+				const struct fb_fillrect *rect);
+void drm_fb_helper_sys_copyarea(struct fb_info *info,
+				const struct fb_copyarea *area);
+void drm_fb_helper_sys_imageblit(struct fb_info *info,
+				 const struct fb_image *image);
+
+void drm_fb_helper_cfb_fillrect(struct fb_info *info,
+				const struct fb_fillrect *rect);
+void drm_fb_helper_cfb_copyarea(struct fb_info *info,
+				const struct fb_copyarea *area);
+void drm_fb_helper_cfb_imageblit(struct fb_info *info,
+				 const struct fb_image *image);
+
 int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info);
 
 int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper);