[PATCH 03/25] drm/fb_helper: Create wrappers for fb_sys_read/write funcs

[Archit Taneja]

Some drm drivers populate their fb_ops with fb_sys_read/write fb sysfs
ops.

Create a drm_fb_helper function  that wraps 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.

Signed-off-by: Archit Taneja <architt at codeaurora.org>
---
 drivers/gpu/drm/Kconfig         |  1 +
 drivers/gpu/drm/drm_fb_helper.c | 20 ++++++++++++++++++++
 include/drm/drm_fb_helper.h     |  5 +++++
 3 files changed, 26 insertions(+)

diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index a66ac44..b284cdc 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -37,6 +37,7 @@ config DRM_KMS_FB_HELPER
 	select FB
 	select FRAMEBUFFER_CONSOLE if !EXPERT
 	select FRAMEBUFFER_CONSOLE_DETECT_PRIMARY if FRAMEBUFFER_CONSOLE
+	select FB_SYS_FOPS
 	help
 	  FBDEV helpers for KMS drivers.
 
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 742377d..795547e 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -744,6 +744,26 @@ void drm_fb_helper_unlink_fbi(struct drm_fb_helper *fb_helper)
 }
 EXPORT_SYMBOL(drm_fb_helper_unlink_fbi);
 
+ssize_t drm_fb_helper_sys_read(struct fb_info *info, char __user *buf,
+			size_t count, loff_t *ppos)
+{
+	if (info)
+		return fb_sys_read(info, buf, count, ppos);
+
+	return -ENODEV;
+}
+EXPORT_SYMBOL(drm_fb_helper_sys_read);
+
+ssize_t drm_fb_helper_sys_write(struct fb_info *info, const char __user *buf,
+			size_t count, loff_t *ppos)
+{
+	if (info)
+		return fb_sys_write(info, buf, count, ppos);
+
+	return -ENODEV;
+}
+EXPORT_SYMBOL(drm_fb_helper_sys_write);
+
 static int setcolreg(struct drm_crtc *crtc, u16 red, u16 green,
 		     u16 blue, u16 regno, struct fb_info *info)
 {
diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h
index 4c90837..f74e59e 100644
--- a/include/drm/drm_fb_helper.h
+++ b/include/drm/drm_fb_helper.h
@@ -147,6 +147,11 @@ void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch,
 
 void drm_fb_helper_unlink_fbi(struct drm_fb_helper *fb_helper);
 
+ssize_t drm_fb_helper_sys_read(struct fb_info *info, char __user *buf,
+			size_t count, loff_t *ppos);
+ssize_t drm_fb_helper_sys_write(struct fb_info *info, const char __user *buf,
+			size_t count, loff_t *ppos);
+
 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);
-- 
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