drm/vkms: Create helper macro for YUV formats

The callback functions for line conversion are almost identical for
semi-planar formats. The generic READ_LINE_YUV_SEMIPLANAR macro
generate all the required boilerplate to process a line from a
semi-planar format.

Reviewed-by: Maíra Canal <mcanal@igalia.com>
Acked-by: Daniel Stone <daniels@collabora.com>
Link: https://lore.kernel.org/r/20250703-b4-new-color-formats-v7-7-15fd8fd2e15c@bootlin.com
Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>

diff --git a/drivers/gpu/drm/vkms/vkms_formats.c b/drivers/gpu/drm/vkms/vkms_formats.c
index cec27a72bc48bf1f4eb0f19856a9446db95f18f9..639b1c7ca43e61e5ea3099fe4d7b0a5e7e9d85e6 100644 (file)
--- a/drivers/gpu/drm/vkms/vkms_formats.c
+++ b/drivers/gpu/drm/vkms/vkms_formats.c
@@ -479,35 +479,56 @@ READ_LINE(R8_read_line, px, u8, argb_u16_from_gray8, *px)
  * - Convert YUV and YVU with the same function (a column swap is needed when setting up
  * plane->conversion_matrix)
  */
-static void semi_planar_yuv_read_line(const struct vkms_plane_state *plane, int x_start,
-                                     int y_start, enum pixel_read_direction direction, int count,
-                                     struct pixel_argb_u16 out_pixel[])
-{
-       u8 *y_plane;
-       u8 *uv_plane;
-
-       packed_pixels_addr_1x1(plane->frame_info, x_start, y_start, 0,
-                              &y_plane);
-       packed_pixels_addr_1x1(plane->frame_info,
-                              x_start / plane->frame_info->fb->format->hsub,
-                              y_start / plane->frame_info->fb->format->vsub, 1,
-                              &uv_plane);
-       int step_y = get_block_step_bytes(plane->frame_info->fb, direction, 0);
-       int step_uv = get_block_step_bytes(plane->frame_info->fb, direction, 1);
-       int subsampling = get_subsampling(plane->frame_info->fb->format, direction);
-       int subsampling_offset = get_subsampling_offset(direction, x_start, y_start);
-       const struct conversion_matrix *conversion_matrix = &plane->conversion_matrix;
 
-       for (int i = 0; i < count; i++) {
-               *out_pixel = argb_u16_from_yuv161616(conversion_matrix, y_plane[0] * 257,
-                                                    uv_plane[0] * 257, uv_plane[1] * 257);
-               out_pixel += 1;
-               y_plane += step_y;
-               if ((i + subsampling_offset + 1) % subsampling == 0)
-                       uv_plane += step_uv;
-       }
+/**
+ * READ_LINE_YUV_SEMIPLANAR() - Generic generator for a read_line function which can be used for yuv
+ * formats with two planes and block_w == block_h == 1.
+ *
+ * @function_name: Function name to generate
+ * @pixel_1_name: temporary pixel name for the first plane used in the @__VA_ARGS__ parameters
+ * @pixel_2_name: temporary pixel name for the second plane used in the @__VA_ARGS__ parameters
+ * @pixel_1_type: Used to specify the type you want to cast the pixel pointer on the plane 1
+ * @pixel_2_type: Used to specify the type you want to cast the pixel pointer on the plane 2
+ * @callback: Callback to call for each pixels. This function should take
+ *            (struct conversion_matrix*, @__VA_ARGS__) as parameter and return a pixel_argb_u16
+ * __VA_ARGS__: Argument to pass inside the callback. You can use @pixel_1_name and @pixel_2_name
+ *               to access current pixel values
+ */
+#define READ_LINE_YUV_SEMIPLANAR(function_name, pixel_1_name, pixel_2_name, pixel_1_type,      \
+                                pixel_2_type, callback, ...)                                   \
+static void function_name(const struct vkms_plane_state *plane, int x_start,                   \
+                int y_start, enum pixel_read_direction direction, int count,                   \
+                struct pixel_argb_u16 out_pixel[])                                             \
+{                                                                                              \
+       u8 *plane_1;                                                                            \
+       u8 *plane_2;                                                                            \
+                                                                                               \
+       packed_pixels_addr_1x1(plane->frame_info, x_start, y_start, 0,                          \
+                              &plane_1);                                                       \
+       packed_pixels_addr_1x1(plane->frame_info,                                               \
+                              x_start / plane->frame_info->fb->format->hsub,                   \
+                              y_start / plane->frame_info->fb->format->vsub, 1,                \
+                              &plane_2);                                                       \
+       int step_1 = get_block_step_bytes(plane->frame_info->fb, direction, 0);                 \
+       int step_2 = get_block_step_bytes(plane->frame_info->fb, direction, 1);                 \
+       int subsampling = get_subsampling(plane->frame_info->fb->format, direction);            \
+       int subsampling_offset = get_subsampling_offset(direction, x_start, y_start);           \
+       const struct conversion_matrix *conversion_matrix = &plane->conversion_matrix;          \
+                                                                                               \
+       for (int i = 0; i < count; i++) {                                                       \
+               pixel_1_type *(pixel_1_name) = (pixel_1_type *)plane_1;                         \
+               pixel_2_type *(pixel_2_name) = (pixel_2_type *)plane_2;                         \
+               *out_pixel = (callback)(conversion_matrix, __VA_ARGS__);                        \
+               out_pixel += 1;                                                                 \
+               plane_1 += step_1;                                                              \
+               if ((i + subsampling_offset + 1) % subsampling == 0)                            \
+                       plane_2 += step_2;                                                      \
+       }                                                                                       \
 }
 
+READ_LINE_YUV_SEMIPLANAR(YUV888_semiplanar_read_line, y, uv, u8, u8, argb_u16_from_yuv161616,
+                        y[0] * 257, uv[0] * 257, uv[1] * 257)
+
 /*
  * This callback can be used for YUV format where each color component is
  * stored in a different plane (often called planar formats). It will
@@ -703,7 +724,7 @@ pixel_read_line_t get_pixel_read_line_function(u32 format)
        case DRM_FORMAT_NV21:
        case DRM_FORMAT_NV61:
        case DRM_FORMAT_NV42:
-               return &semi_planar_yuv_read_line;
+               return &YUV888_semiplanar_read_line;
        case DRM_FORMAT_YUV420:
        case DRM_FORMAT_YUV422:
        case DRM_FORMAT_YUV444: