Hi

Am 12.10.26 um 19:08 schrieb Ho Jie Feng:
Add a helper for devices that use packed UYVY but accept XRGB8888
framebuffers.

Is there a description of UYVY available somewhere?


Signed-off-by: Ho Jie Feng <[email protected]>
---
This is used for a driver, ms912x that I will be submitting. It only
supports uyvy framebuffers.

Please resubmit as part of the driver series. We're not going to merge it without callers anyway.


  drivers/gpu/drm/drm_format_helper.c   | 73 +++++++++++++++++++++++++++
  drivers/gpu/drm/drm_format_internal.h | 21 ++++++++
  include/drm/drm_format_helper.h       |  4 ++
  3 files changed, 98 insertions(+)

diff --git a/drivers/gpu/drm/drm_format_helper.c 
b/drivers/gpu/drm/drm_format_helper.c
index 6cddf05c493bd..606733ca43fb4 100644
--- a/drivers/gpu/drm/drm_format_helper.c
+++ b/drivers/gpu/drm/drm_format_helper.c
@@ -1379,3 +1379,76 @@ void drm_fb_xrgb8888_to_gray2(struct iosys_map *dst, 
const unsigned int *dst_pit
  }
  EXPORT_SYMBOL(drm_fb_xrgb8888_to_gray2);
+static void drm_fb_xrgb8888_to_uyvy_line(void *dbuf, const void *sbuf, unsigned int width)
+{
+       u8 *transfer_buffer = dbuf;
+       const __le32 *temp_buffer = sbuf;

For naming, please follow the conventions used by the other helpers in this file.

+       unsigned int i, dst_offset = 0;
+       unsigned int pixel1, pixel2;
+       unsigned int r1, g1, b1, r2, g2, b2;
+       unsigned int r, g, b;
+       unsigned int v, y1, u, y2;
+
+       for (i = 0; i < width; i += 2) {
+               pixel1 = le32_to_cpup(&temp_buffer[i]);
+               pixel2 = le32_to_cpup(&temp_buffer[i + 1]);
+
+               r1 = (pixel1 & 0x00ff0000) >> 16;
+               g1 = (pixel1 & 0x0000ff00) >> 8;
+               b1 =  pixel1 & 0x000000ff;
+               r2 = (pixel2 & 0x00ff0000) >> 16;
+               g2 = (pixel2 & 0x0000ff00) >> 8;
+               b2 =  pixel2 & 0x000000ff;
+
+               y1 = drm_pixel_rgb_to_y_bt601(r1, g1, b1);
+               y2 = drm_pixel_rgb_to_y_bt601(r2, g2, b2);
+
+               r = r1 + r2;
+               g = g1 + g2;
+               b = b1 + b2;
+
+               v = drm_pixel_rgb2_to_v_bt601(r, g, b);
+               u = drm_pixel_rgb2_to_u_bt601(r, g, b);
+
+               transfer_buffer[dst_offset++] = u;
+               transfer_buffer[dst_offset++] = y1;
+               transfer_buffer[dst_offset++] = v;
+               transfer_buffer[dst_offset++] = y2;

Rather that writing bytes individually, use put_unaligned_le32() or a similar helper.  Byte order within a pixel is little endian, although I'm not sure what this means for UYVY.

+       }
+}
+
+/**
+ * drm_fb_xrgb8888_to_uyvy - Convert XRGB8888 to UYVY clip buffer
+ * @dst: Array of UYVY destination buffers
+ * @dst_pitch: Array of numbers of bytes between the start of two consecutive 
scanlines
+ *             within @dst; can be NULL if scanlines are stored next to each 
other.
+ * @src: Array of XRGB8888 source buffers
+ * @fb: DRM framebuffer
+ * @clip: Clip rectangle area to copy; x1 and x2 must be even
+ * @state: Transform and conversion state
+ *
+ * This function copies parts of a framebuffer to display memory and converts 
the
+ * color format during the process. The parameters @dst, @dst_pitch and @src 
refer
+ * to arrays. Each array must have at least as many entries as there are 
planes in
+ * @fb's format. Each entry stores the value for the format's respective color 
plane
+ * at the same index.
+ *
+ * This function does not apply clipping on @dst (i.e. the destination is at 
the
+ * top-left corner).
+ *
+ * Drivers can use this function for UYVY devices that don't support XRGB8888
+ * natively. ITU BT.601 is being used for the RGB -> YUV conversion.
+ */
+void drm_fb_xrgb8888_to_uyvy(struct iosys_map *dst, const unsigned int 
*dst_pitch,
+                            const struct iosys_map *src, const struct 
drm_framebuffer *fb,
+                            const struct drm_rect *clip, struct 
drm_format_conv_state *state)
+{
+       static const u8 dst_pixsize[DRM_FORMAT_MAX_PLANES] = {
+               2,
+       };
+
+       drm_fb_xfrm(dst, dst_pitch, dst_pixsize, src, fb, clip, false, state,
+                   drm_fb_xrgb8888_to_uyvy_line);
+}
+EXPORT_SYMBOL(drm_fb_xrgb8888_to_uyvy);
+
diff --git a/drivers/gpu/drm/drm_format_internal.h 
b/drivers/gpu/drm/drm_format_internal.h
index ce29dd05bcc55..7a4cfb0d188cb 100644
--- a/drivers/gpu/drm/drm_format_internal.h
+++ b/drivers/gpu/drm/drm_format_internal.h
@@ -159,6 +159,27 @@ static inline u32 drm_pixel_xrgb8888_to_abgr2101010(u32 
pix)
               drm_pixel_xrgb8888_to_xbgr2101010(pix);
  }
+static inline u32 drm_pixel_rgb_to_y_bt601(u32 r, u32 g, u32 b)
+{
+       const u32 luma = (16U << 16) + 16829 * r + 33039 * g + 6416 * b + 32768;
+
+       return luma >> 16;
+}
+
+static inline u32 drm_pixel_rgb2_to_u_bt601(u32 r2, u32 g2, u32 b2)
+{
+       const u32 u = (128U << 17) - 9714 * r2 - 19071 * g2 + 28784 * b2 + 
65536;
+
+       return u >> 17;
+}
+
+static inline u32 drm_pixel_rgb2_to_v_bt601(u32 r2, u32 g2, u32 b2)
+{
+       const u32 v = (128U << 17) + 28784 * r2 - 24103 * g2 - 4681 * b2 + 
65536;
+
+       return v >> 17;
+}
+

These helpers seem too fine-grained. IMHO it would be better to have a helper like  drm_pixel_rgb_to_uyvy() that takes two RGB values and returns the assembled 16-bit UYVY value.

Best regards
Thomas

  /*
   * Conversion from ARGB8888
   */
diff --git a/include/drm/drm_format_helper.h b/include/drm/drm_format_helper.h
index 2b5c1aef80b0e..e50f96e07484c 100644
--- a/include/drm/drm_format_helper.h
+++ b/include/drm/drm_format_helper.h
@@ -136,4 +136,8 @@ void drm_fb_xrgb8888_to_gray2(struct iosys_map *dst, const 
unsigned int *dst_pit
                              const struct iosys_map *src, const struct 
drm_framebuffer *fb,
                              const struct drm_rect *clip, struct 
drm_format_conv_state *state);
+void drm_fb_xrgb8888_to_uyvy(struct iosys_map *dst, const unsigned int *dst_pitch,
+                            const struct iosys_map *src, const struct 
drm_framebuffer *fb,
+                            const struct drm_rect *clip, struct 
drm_format_conv_state *state);
+
  #endif /* __LINUX_DRM_FORMAT_HELPER_H */

--
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Stefan Gaiser, Jochen Jaser, Abhinav Puri, (HRB 36809, AG Nürnberg)


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