[PATCH 01/23] sandbox: video: Support 8bpp depth

[Simon Glass]

At present sandbox only supports 16 and 32bpp depths, since those are the
easy ones with SDL.

We can support other depths by manually converting the pixel formats. Add
support for this, to enable an 8ppp (monochrome) format.

Signed-off-by: Simon Glass <sjg at chromium.org>
---

 arch/sandbox/cpu/sdl.c      | 65 ++++++++++++++++++++++++++++++++++---
 drivers/video/sandbox_sdl.c | 23 +++++++++----
 2 files changed, 77 insertions(+), 11 deletions(-)

diff --git a/arch/sandbox/cpu/sdl.c b/arch/sandbox/cpu/sdl.c
index bef5abd039d..7ff0df2ee54 100644
--- a/arch/sandbox/cpu/sdl.c
+++ b/arch/sandbox/cpu/sdl.c
@@ -44,6 +44,8 @@ struct buf_info {
  * @stopping: true if audio will stop once it runs out of data
  * @texture: SDL texture to use for U-Boot display contents
  * @renderer: SDL renderer to use
+ * @src_depth: Number of bits per pixel in the source frame buffer (that we read
+ * from and render to SDL)
  */
 static struct sdl_info {
 	int width;
@@ -61,6 +63,7 @@ static struct sdl_info {
 	bool stopping;
 	SDL_Texture *texture;
 	SDL_Renderer *renderer;
+	int src_depth;
 } sdl;
 
 static void sandbox_sdl_poll_events(void)
@@ -126,6 +129,9 @@ int sandbox_sdl_init_display(int width, int height, int log2_bpp,
 	if (!SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, "1"))
 		printf("Unable to init hinting: %s", SDL_GetError());
 
+	sdl.src_depth = 1 << log2_bpp;
+	if (log2_bpp != 4 && log2_bpp != 5)
+		log2_bpp = 5;
 	sdl.depth = 1 << log2_bpp;
 	sdl.pitch = sdl.width * sdl.depth / 8;
 	SDL_Window *screen = SDL_CreateWindow("U-Boot", SDL_WINDOWPOS_UNDEFINED,
@@ -137,10 +143,6 @@ int sandbox_sdl_init_display(int width, int height, int log2_bpp,
 		       SDL_GetError());
 		return -EIO;
 	}
-	if (log2_bpp != 4 && log2_bpp != 5) {
-		printf("U-Boot SDL does not support depth %d\n", log2_bpp);
-		return -EINVAL;
-	}
 	sdl.renderer = SDL_CreateRenderer(screen, -1,
 					  SDL_RENDERER_ACCELERATED |
 					  SDL_RENDERER_PRESENTVSYNC);
@@ -165,6 +167,55 @@ int sandbox_sdl_init_display(int width, int height, int log2_bpp,
 	return 0;
 }
 
+static int copy_to_texture(void *lcd_base)
+{
+	char *dest;
+	int pitch, x, y;
+	int src_pitch;
+	void *pixels;
+	char *src;
+	int ret;
+
+	if (sdl.src_depth == sdl.depth) {
+		SDL_UpdateTexture(sdl.texture, NULL, lcd_base, sdl.pitch);
+		return 0;
+	}
+
+	/*
+	 * We only support copying from an 8bpp to a 32bpp texture since the
+	 * other cases are supported directly by the texture.
+	 */
+	if (sdl.depth != 32 && sdl.src_depth != 8) {
+		printf("Need depth 32bpp for copy\n");
+		return -EINVAL;
+	}
+
+	ret = SDL_LockTexture(sdl.texture, NULL, &pixels, &pitch);
+	if (ret) {
+		printf("SDL lock %d: %s\n", ret, SDL_GetError());
+		return ret;
+	}
+
+	/* Copy the pixels one by one */
+	src_pitch = sdl.width * sdl.src_depth / 8;
+	for (y = 0; y < sdl.height; y++) {
+		char val;
+
+		dest = pixels + y * pitch;
+		src = lcd_base + src_pitch * y;
+		for (x = 0; x < sdl.width; x++, dest += 4) {
+			val = *src++;
+			dest[0] = val;
+			dest[1] = val;
+			dest[2] = val;
+			dest[3] = 0;
+		}
+	}
+	SDL_UnlockTexture(sdl.texture);
+
+	return 0;
+}
+
 int sandbox_sdl_sync(void *lcd_base)
 {
 	struct SDL_Rect rect;
@@ -173,7 +224,11 @@ int sandbox_sdl_sync(void *lcd_base)
 	if (!sdl.texture)
 		return 0;
 	SDL_RenderClear(sdl.renderer);
-	SDL_UpdateTexture(sdl.texture, NULL, lcd_base, sdl.pitch);
+	ret = copy_to_texture(lcd_base);
+	if (ret) {
+		printf("copy_to_texture: %d: %s\n", ret, SDL_GetError());
+		return -EIO;
+	}
 	ret = SDL_RenderCopy(sdl.renderer, sdl.texture, NULL, NULL);
 	if (ret) {
 		printf("SDL copy %d: %s\n", ret, SDL_GetError());
diff --git a/drivers/video/sandbox_sdl.c b/drivers/video/sandbox_sdl.c
index 5956b59ce49..32739de4feb 100644
--- a/drivers/video/sandbox_sdl.c
+++ b/drivers/video/sandbox_sdl.c
@@ -48,22 +48,33 @@ static int sandbox_sdl_probe(struct udevice *dev)
 	return 0;
 }
 
-static int sandbox_sdl_bind(struct udevice *dev)
+static void set_bpp(struct udevice *dev, enum video_log2_bpp l2bpp)
 {
 	struct video_uc_plat *uc_plat = dev_get_uclass_plat(dev);
 	struct sandbox_sdl_plat *plat = dev_get_plat(dev);
-	int ret = 0;
 
-	plat->xres = dev_read_u32_default(dev, "xres", LCD_MAX_WIDTH);
-	plat->yres = dev_read_u32_default(dev, "yres", LCD_MAX_HEIGHT);
-	plat->bpix = dev_read_u32_default(dev, "log2-depth", VIDEO_BPP16);
-	plat->rot = dev_read_u32_default(dev, "rotate", 0);
+	plat->bpix = l2bpp;
+
 	uc_plat->size = plat->xres * plat->yres * (1 << plat->bpix) / 8;
 
 	/* Allow space for two buffers, the lower one being the copy buffer */
 	log_debug("Frame buffer size %x\n", uc_plat->size);
 	if (IS_ENABLED(CONFIG_VIDEO_COPY))
 		uc_plat->size *= 2;
+}
+
+static int sandbox_sdl_bind(struct udevice *dev)
+{
+	struct sandbox_sdl_plat *plat = dev_get_plat(dev);
+	enum video_log2_bpp l2bpp;
+	int ret = 0;
+
+	plat->xres = dev_read_u32_default(dev, "xres", LCD_MAX_WIDTH);
+	plat->yres = dev_read_u32_default(dev, "yres", LCD_MAX_HEIGHT);
+	l2bpp = dev_read_u32_default(dev, "log2-depth", VIDEO_BPP16);
+	plat->rot = dev_read_u32_default(dev, "rotate", 0);
+
+	set_bpp(dev, l2bpp);
 
 	return ret;
 }
-- 
2.34.0.rc2.393.gf8c9666880-goog