[PATCH v5 03/11] drm: Add drm_mode_create_rotation_property()

From: sagar . a . kamble
Date: Mon Feb 10 2014 - 02:31:39 EST


From: Ville SyrjÃlà <ville.syrjala at linux.intel.com>

Add a function to create a standards compliant rotation property.

v4: For creating rotation bitmask property send number of values
as only number of set rotations

Cc: David Airlie <airlied@xxxxxxxx>
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Ville SyrjÃlà <ville.syrjala@xxxxxxxxxxxxxxx>
Signed-off-by: Sagar Kamble <sagar.a.kamble@xxxxxxxxx>
---
drivers/gpu/drm/drm_crtc.c | 33 +++++++++++++++++++++++++++++++++
include/drm/drm_crtc.h | 2 ++
2 files changed, 35 insertions(+)

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 628d3d3..e7bbbad 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -4118,3 +4118,36 @@ void drm_mode_config_cleanup(struct drm_device *dev)
idr_destroy(&dev->mode_config.crtc_idr);
}
EXPORT_SYMBOL(drm_mode_config_cleanup);
+
+/*
+* Function to get number of bits set in bitmask
+* using Brian Kernighan's Algorithm
+*/
+unsigned int bits_set(unsigned int n)
+{
+ unsigned int count = 0;
+
+ while (n) {
+ n &= (n-1);
+ count ++;
+ }
+ return count;
+}
+
+struct drm_property *drm_mode_create_rotation_property(struct drm_device *dev,
+ unsigned int supported_rotations)
+{
+ static const struct drm_prop_enum_list props[] = {
+ { DRM_ROTATE_0, "rotate-0" },
+ { DRM_ROTATE_90, "rotate-90" },
+ { DRM_ROTATE_180, "rotate-180" },
+ { DRM_ROTATE_270, "rotate-270" },
+ { DRM_REFLECT_X, "reflect-x" },
+ { DRM_REFLECT_Y, "reflect-y" },
+ };
+
+ return drm_property_create_bitmask(dev, 0, "rotation",
+ props, bits_set(supported_rotations),
+ supported_rotations);
+}
+EXPORT_SYMBOL(drm_mode_create_rotation_property);
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index 41b86d2..4b3ac70 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -1183,6 +1183,8 @@ extern int drm_format_plane_cpp(uint32_t format, int plane);
extern int drm_format_horz_chroma_subsampling(uint32_t format);
extern int drm_format_vert_chroma_subsampling(uint32_t format);
extern const char *drm_get_format_name(uint32_t format);
+extern struct drm_property *drm_mode_create_rotation_property(struct drm_device *dev,
+ unsigned int supported_rotations);

/* Helpers */
static inline struct drm_crtc *drm_crtc_find(struct drm_device *dev,
--
1.8.5

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