[PATCH] drm/vkms: Add support for ABGR8888 pixel format

[Paz Zcharya <pazz@chromium.org>]

Add support for pixel format ABGR8888, which is the default format
on Android devices. This will allow us to use VKMS as the default
display driver in Android Emulator (Cuttlefish) and increase VKMS
adoption.

Signed-off-by: Paz Zcharya <pazz@chromium.org>
---

 drivers/gpu/drm/vkms/vkms_formats.c   | 20 ++++++++++++++++++++
 drivers/gpu/drm/vkms/vkms_plane.c     |  1 +
 drivers/gpu/drm/vkms/vkms_writeback.c |  1 +
 3 files changed, 22 insertions(+)

diff --git a/drivers/gpu/drm/vkms/vkms_formats.c b/drivers/gpu/drm/vkms/vkms_formats.c
index 040b7f113a3b..9e9d7290388e 100644
--- a/drivers/gpu/drm/vkms/vkms_formats.c
+++ b/drivers/gpu/drm/vkms/vkms_formats.c
@@ -73,6 +73,14 @@ static void XRGB8888_to_argb_u16(u8 *src_pixels, struct pixel_argb_u16 *out_pixe
 	out_pixel->b = (u16)src_pixels[0] * 257;
 }
 
+static void ABGR8888_to_argb_u16(u8 *src_pixels, struct pixel_argb_u16 *out_pixel)
+{
+	out_pixel->a = (u16)src_pixels[3] * 257;
+	out_pixel->b = (u16)src_pixels[2] * 257;
+	out_pixel->g = (u16)src_pixels[1] * 257;
+	out_pixel->r = (u16)src_pixels[0] * 257;
+}
+
 static void ARGB16161616_to_argb_u16(u8 *src_pixels, struct pixel_argb_u16 *out_pixel)
 {
 	__le16 *pixels = (__force __le16 *)src_pixels;
@@ -176,6 +184,14 @@ static void argb_u16_to_XRGB8888(u8 *dst_pixels, struct pixel_argb_u16 *in_pixel
 	dst_pixels[0] = DIV_ROUND_CLOSEST(in_pixel->b, 257);
 }
 
+static void argb_u16_to_ABGR8888(u8 *dst_pixels, struct pixel_argb_u16 *in_pixel)
+{
+	dst_pixels[3] = DIV_ROUND_CLOSEST(in_pixel->a, 257);
+	dst_pixels[2] = DIV_ROUND_CLOSEST(in_pixel->b, 257);
+	dst_pixels[1] = DIV_ROUND_CLOSEST(in_pixel->g, 257);
+	dst_pixels[0] = DIV_ROUND_CLOSEST(in_pixel->r, 257);
+}
+
 static void argb_u16_to_ARGB16161616(u8 *dst_pixels, struct pixel_argb_u16 *in_pixel)
 {
 	__le16 *pixels = (__force __le16 *)dst_pixels;
@@ -234,6 +250,8 @@ void *get_pixel_conversion_function(u32 format)
 		return &ARGB8888_to_argb_u16;
 	case DRM_FORMAT_XRGB8888:
 		return &XRGB8888_to_argb_u16;
+	case DRM_FORMAT_ABGR8888:
+		return &ABGR8888_to_argb_u16;
 	case DRM_FORMAT_ARGB16161616:
 		return &ARGB16161616_to_argb_u16;
 	case DRM_FORMAT_XRGB16161616:
@@ -252,6 +270,8 @@ void *get_pixel_write_function(u32 format)
 		return &argb_u16_to_ARGB8888;
 	case DRM_FORMAT_XRGB8888:
 		return &argb_u16_to_XRGB8888;
+	case DRM_FORMAT_ABGR8888:
+		return &argb_u16_to_ABGR8888;
 	case DRM_FORMAT_ARGB16161616:
 		return &argb_u16_to_ARGB16161616;
 	case DRM_FORMAT_XRGB16161616:
diff --git a/drivers/gpu/drm/vkms/vkms_plane.c b/drivers/gpu/drm/vkms/vkms_plane.c
index e5c625ab8e3e..8efd585fc34c 100644
--- a/drivers/gpu/drm/vkms/vkms_plane.c
+++ b/drivers/gpu/drm/vkms/vkms_plane.c
@@ -15,6 +15,7 @@
 static const u32 vkms_formats[] = {
 	DRM_FORMAT_ARGB8888,
 	DRM_FORMAT_XRGB8888,
+	DRM_FORMAT_ABGR8888,
 	DRM_FORMAT_XRGB16161616,
 	DRM_FORMAT_ARGB16161616,
 	DRM_FORMAT_RGB565
diff --git a/drivers/gpu/drm/vkms/vkms_writeback.c b/drivers/gpu/drm/vkms/vkms_writeback.c
index bc724cbd5e3a..04cb9c58e7ad 100644
--- a/drivers/gpu/drm/vkms/vkms_writeback.c
+++ b/drivers/gpu/drm/vkms/vkms_writeback.c
@@ -17,6 +17,7 @@
 static const u32 vkms_wb_formats[] = {
 	DRM_FORMAT_ARGB8888,
 	DRM_FORMAT_XRGB8888,
+	DRM_FORMAT_ABGR8888,
 	DRM_FORMAT_XRGB16161616,
 	DRM_FORMAT_ARGB16161616,
 	DRM_FORMAT_RGB565
-- 
2.47.0.rc0.187.ge670bccf7e-goog