[PATCH 6.18.y 1/3] fb: Add dev_of_fbinfo() helper for optional sysfs support

[Sasha Levin <sashal@kernel.org>]

From: Chintan Patel <chintanlike@gmail.com>

[ Upstream commit 39b65316fe9d6d3f730632408ace28d49c5845a4 ]

Add dev_of_fbinfo() to return the framebuffer struct device when
CONFIG_FB_DEVICE is enabled, or NULL otherwise.

This allows fbdev drivers to use sysfs interfaces via runtime checks
instead of CONFIG_FB_DEVICE ifdefs, keeping the code clean while
remaining fully buildable.

Suggested-by: Helge Deller <deller@gmx.de>
Reviewed-by: Helge Deller <deller@gmx.de>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Chintan Patel <chintanlike@gmail.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Helge Deller <deller@gmx.de>
Stable-dep-of: 317a8be73091 ("fbdev: sh_mobile_lcdcfb: Restore the per-overlay sysfs attributes")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 include/linux/fb.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/include/linux/fb.h b/include/linux/fb.h
index f622f5f520cf0..e50fc8f0801e6 100644
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -631,6 +631,15 @@ static inline void unlock_fb_info(struct fb_info *info)
 	mutex_unlock(&info->lock);
 }
 
+static inline struct device *dev_of_fbinfo(const struct fb_info *info)
+{
+#ifdef CONFIG_FB_DEVICE
+	return info->dev;
+#else
+	return NULL;
+#endif
+}
+
 static inline void __fb_pad_aligned_buffer(u8 *dst, u32 d_pitch,
 					   u8 *src, u32 s_pitch, u32 height)
 {
-- 
2.53.0