drm: add drm_fb_xrgb8888_to_rgb565_dstclip()

It is a drm_fb_xrgb8888_to_rgb565() variant which checks the clip
rectangle for the destination too.

Common code between drm_fb_xrgb8888_to_rgb565() and
drm_fb_xrgb8888_to_rgb565_dstclip() was factored out into the
drm_fb_xrgb8888_to_rgb565_lines() helper function.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Noralf Trønnes <noralf@tronnes.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20190405095219.9231-4-kraxel@redhat.com

diff --git a/drivers/gpu/drm/drm_format_helper.c b/drivers/gpu/drm/drm_format_helper.c
index 55a2d62..2467755 100644 (file)
--- a/drivers/gpu/drm/drm_format_helper.c
+++ b/drivers/gpu/drm/drm_format_helper.c
@@ -110,6 +110,44 @@ void drm_fb_swab16(u16 *dst, void *vaddr, struct drm_framebuffer *fb,
 }
 EXPORT_SYMBOL(drm_fb_swab16);
 
+static void drm_fb_xrgb8888_to_rgb565_lines(void *dst, unsigned int dst_pitch,
+                                           void *src, unsigned int src_pitch,
+                                           unsigned int src_linelength,
+                                           unsigned int lines,
+                                           bool swap)
+{
+       unsigned int linepixels = src_linelength / sizeof(u32);
+       unsigned int x, y;
+       u32 *sbuf;
+       u16 *dbuf, val16;
+
+       /*
+        * The cma memory is write-combined so reads are uncached.
+        * Speed up by fetching one line at a time.
+        */
+       sbuf = kmalloc(src_linelength, GFP_KERNEL);
+       if (!sbuf)
+               return;
+
+       for (y = 0; y < lines; y++) {
+               memcpy(sbuf, src, src_linelength);
+               dbuf = dst;
+               for (x = 0; x < linepixels; x++) {
+                       val16 = ((sbuf[x] & 0x00F80000) >> 8) |
+                               ((sbuf[x] & 0x0000FC00) >> 5) |
+                               ((sbuf[x] & 0x000000F8) >> 3);
+                       if (swap)
+                               *dbuf++ = swab16(val16);
+                       else
+                               *dbuf++ = val16;
+               }
+               src += src_pitch;
+               dst += dst_pitch;
+       }
+
+       kfree(sbuf);
+}
+
 /**
  * drm_fb_xrgb8888_to_rgb565 - Convert XRGB8888 to RGB565 clip buffer
  * @dst: RGB565 destination buffer
@@ -120,44 +158,57 @@ EXPORT_SYMBOL(drm_fb_swab16);
  *
  * Drivers can use this function for RGB565 devices that don't natively
  * support XRGB8888.
+ *
+ * This function does not apply clipping on dst, i.e. the destination
+ * is a small buffer containing the clip rect only.
  */
-void drm_fb_xrgb8888_to_rgb565(u16 *dst, void *vaddr,
+void drm_fb_xrgb8888_to_rgb565(void *dst, void *vaddr,
                               struct drm_framebuffer *fb,
                               struct drm_rect *clip, bool swap)
 {
-       size_t len = (clip->x2 - clip->x1) * sizeof(u32);
-       unsigned int x, y;
-       u32 *src, *buf;
-       u16 val16;
+       unsigned int src_offset = (clip->y1 * fb->pitches[0])
+               + (clip->x1 * sizeof(u32));
+       size_t src_len = (clip->x2 - clip->x1) * sizeof(u32);
+       size_t dst_len = (clip->x2 - clip->x1) * sizeof(u16);
 
-       /*
-        * The cma memory is write-combined so reads are uncached.
-        * Speed up by fetching one line at a time.
-        */
-       buf = kmalloc(len, GFP_KERNEL);
-       if (!buf)
-               return;
+       drm_fb_xrgb8888_to_rgb565_lines(dst, dst_len,
+                                       vaddr + src_offset, fb->pitches[0],
+                                       src_len, clip->y2 - clip->y1,
+                                       swap);
+}
+EXPORT_SYMBOL(drm_fb_xrgb8888_to_rgb565);
 
-       for (y = clip->y1; y < clip->y2; y++) {
-               src = vaddr + (y * fb->pitches[0]);
-               src += clip->x1;
-               memcpy(buf, src, len);
-               src = buf;
-               for (x = clip->x1; x < clip->x2; x++) {
-                       val16 = ((*src & 0x00F80000) >> 8) |
-                               ((*src & 0x0000FC00) >> 5) |
-                               ((*src & 0x000000F8) >> 3);
-                       src++;
-                       if (swap)
-                               *dst++ = swab16(val16);
-                       else
-                               *dst++ = val16;
-               }
-       }
+/**
+ * drm_fb_xrgb8888_to_rgb565_dstclip - Convert XRGB8888 to RGB565 clip buffer
+ * @dst: RGB565 destination buffer
+ * @dst_pitch: destination buffer pitch
+ * @vaddr: XRGB8888 source buffer
+ * @fb: DRM framebuffer
+ * @clip: Clip rectangle area to copy
+ * @swap: Swap bytes
+ *
+ * Drivers can use this function for RGB565 devices that don't natively
+ * support XRGB8888.
+ *
+ * This function applies clipping on dst, i.e. the destination is a
+ * full framebuffer but only the clip rect content is copied over.
+ */
+void drm_fb_xrgb8888_to_rgb565_dstclip(void *dst, unsigned int dst_pitch,
+                                      void *vaddr, struct drm_framebuffer *fb,
+                                      struct drm_rect *clip, bool swap)
+{
+       unsigned int src_offset = (clip->y1 * fb->pitches[0])
+               + (clip->x1 * sizeof(u32));
+       unsigned int dst_offset = (clip->y1 * dst_pitch)
+               + (clip->x1 * sizeof(u16));
+       size_t src_len = (clip->x2 - clip->x1) * sizeof(u32);
 
-       kfree(buf);
+       drm_fb_xrgb8888_to_rgb565_lines(dst + dst_offset, dst_pitch,
+                                       vaddr + src_offset, fb->pitches[0],
+                                       src_len, clip->y2 - clip->y1,
+                                       swap);
 }
-EXPORT_SYMBOL(drm_fb_xrgb8888_to_rgb565);
+EXPORT_SYMBOL(drm_fb_xrgb8888_to_rgb565_dstclip);
 
 /**
  * drm_fb_xrgb8888_to_gray8 - Convert XRGB8888 to grayscale

diff --git a/include/drm/drm_format_helper.h b/include/drm/drm_format_helper.h
index c52b7b9..a84d71f 100644 (file)
--- a/include/drm/drm_format_helper.h
+++ b/include/drm/drm_format_helper.h
@@ -19,9 +19,12 @@ void drm_fb_memcpy_dstclip(void *dst, void *vaddr, struct drm_framebuffer *fb,
                           struct drm_rect *clip);
 void drm_fb_swab16(u16 *dst, void *vaddr, struct drm_framebuffer *fb,
                   struct drm_rect *clip);
-void drm_fb_xrgb8888_to_rgb565(u16 *dst, void *vaddr,
+void drm_fb_xrgb8888_to_rgb565(void *dst, void *vaddr,
                               struct drm_framebuffer *fb,
                               struct drm_rect *clip, bool swap);
+void drm_fb_xrgb8888_to_rgb565_dstclip(void *dst, unsigned int dst_pitch,
+                                      void *vaddr, struct drm_framebuffer *fb,
+                                      struct drm_rect *clip, bool swap);
 void drm_fb_xrgb8888_to_gray8(u8 *dst, void *vaddr, struct drm_framebuffer *fb,
                              struct drm_rect *clip);