[PATCH v7 4/9] drm/panic: Add drm_panic_is_format_supported()

[Jocelyn Falempe <jfalempe@xxxxxxxxxx>]

So driver knows early if drm_panic will be able to display something
on the current scanout buffer.

Signed-off-by: Jocelyn Falempe <jfalempe@xxxxxxxxxx>
---
 drivers/gpu/drm/drm_panic.c | 13 +++++++++++++
 include/drm/drm_panic.h     |  4 ++++
 2 files changed, 17 insertions(+)

diff --git a/drivers/gpu/drm/drm_panic.c b/drivers/gpu/drm/drm_panic.c
index 362a696ec48a..c68167cd4c08 100644
--- a/drivers/gpu/drm/drm_panic.c
+++ b/drivers/gpu/drm/drm_panic.c
@@ -348,6 +348,19 @@ void drm_panic_unregister(struct drm_device *dev)
 }
 EXPORT_SYMBOL(drm_panic_unregister);
 
+/**
+ * drm_panic_is_format_supported()
+ * @format: a fourcc color code
+ * Returns: true if supported, false otherwise.
+ *
+ * Check if drm_panic will be able to use this color format.
+ */
+bool drm_panic_is_format_supported(u32 format)
+{
+	return drm_fb_convert_from_xrgb8888(0xffffff, format) != 0;
+}
+EXPORT_SYMBOL(drm_panic_is_format_supported);
+
 /**
  * drm_panic_init() - Initialize drm-panic subsystem
  *
diff --git a/include/drm/drm_panic.h b/include/drm/drm_panic.h
index bcf392b6fa1b..1549c8eb8dcc 100644
--- a/include/drm/drm_panic.h
+++ b/include/drm/drm_panic.h
@@ -84,6 +84,8 @@ void drm_panic_exit(void);
 void drm_panic_register(struct drm_device *dev);
 void drm_panic_unregister(struct drm_device *dev);
 
+bool drm_panic_is_format_supported(u32 format);
+
 #else
 
 static inline void drm_panic_init(void) {}
@@ -92,6 +94,8 @@ static inline void drm_panic_exit(void) {}
 static inline void drm_panic_register(struct drm_device *dev) {}
 static inline void drm_panic_unregister(struct drm_device *dev) {}
 
+bool drm_panic_is_format_supported(u32 format) {return false; }
+
 #endif
 
 #endif /* __DRM_PANIC_H__ */
-- 
2.43.0