[PATCH 0/2] Add monochrome framebuffer support to simple-framebuffer

[PATCH 0/2] Add monochrome framebuffer support to simple-framebuffer

[Sebastian Raase]

This patch series adds support for monochrome framebuffers (1 bpp, packed-pixel)
to simple-framebuffer.

Monochrome framebuffers require far less video memory and bandwidth than
16bpp or 32bpp framebuffers, making them useful for small devices or FPGA
implementations.

Sebastian Raase (2):
  fbdev: simplefb: Add mono framebuffer format
  dt-bindings: display: simple-framebuffer: Document mono format

 .../devicetree/bindings/display/simple-framebuffer.yaml         | 2 ++
 drivers/video/fbdev/simplefb.c                                  | 2 ++
 include/linux/platform_data/simplefb.h                          | 1 +
 3 files changed, 5 insertions(+)

-- 
2.47.3

[PATCH 1/2] fbdev: simplefb: Add mono framebuffer format

[Sebastian Raase]

Add a new simple-framebuffer format for monochrome 1 bit-per-pixel
framebuffers. Monochrome framebuffers are not true color, so their
visual is set to FB_VISUAL_MONO10 (set pixels are bright).

Signed-off-by: Sebastian Raase <linux@sraa.de>
---
 drivers/video/fbdev/simplefb.c         | 2 ++
 include/linux/platform_data/simplefb.h | 1 +
 2 files changed, 3 insertions(+)

diff --git a/drivers/video/fbdev/simplefb.c b/drivers/video/fbdev/simplefb.c
index 60e5dcec201f..4662101885ec 100644
--- a/drivers/video/fbdev/simplefb.c
+++ b/drivers/video/fbdev/simplefb.c
@@ -583,6 +583,8 @@ static int simplefb_probe(struct platform_device *pdev)
 	info->fix.smem_start = mem->start;
 	info->fix.smem_len = resource_size(mem);
 	info->fix.line_length = params.stride;
+	if (params.format->bits_per_pixel == 1)
+		info->fix.visual = FB_VISUAL_MONO10;
 
 	info->var = simplefb_var;
 	info->var.xres = params.width;
diff --git a/include/linux/platform_data/simplefb.h b/include/linux/platform_data/simplefb.h
index 4f94d52ac99f..9b6d822145c9 100644
--- a/include/linux/platform_data/simplefb.h
+++ b/include/linux/platform_data/simplefb.h
@@ -15,6 +15,7 @@
 /* format array, use it to initialize a "struct simplefb_format" array */
 #define SIMPLEFB_FORMATS \
 { \
+	{ "mono", 1, {0, 1}, {0, 1}, {0, 1}, {0, 0}, DRM_FORMAT_R1 }, \
 	{ "r5g6b5", 16, {11, 5}, {5, 6}, {0, 5}, {0, 0}, DRM_FORMAT_RGB565 }, \
 	{ "r5g5b5a1", 16, {11, 5}, {6, 5}, {1, 5}, {0, 1}, DRM_FORMAT_RGBA5551 }, \
 	{ "x1r5g5b5", 16, {10, 5}, {5, 5}, {0, 5}, {0, 0}, DRM_FORMAT_XRGB1555 }, \
-- 
2.47.3

[PATCH 2/2] dt-bindings: display: simple-framebuffer: Document mono format

[Sebastian Raase]

This is a 1 bit-per-pixel monochrome format, with 8 pixels/byte.

Signed-off-by: Sebastian Raase <linux@sraa.de>
---
 .../devicetree/bindings/display/simple-framebuffer.yaml         | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/display/simple-framebuffer.yaml b/Documentation/devicetree/bindings/display/simple-framebuffer.yaml
index 45ffdebc9d86..c627ec088434 100644
--- a/Documentation/devicetree/bindings/display/simple-framebuffer.yaml
+++ b/Documentation/devicetree/bindings/display/simple-framebuffer.yaml
@@ -94,6 +94,7 @@ properties:
   format:
     description: >
       Format of the framebuffer:
+        * `mono` - 1-bit packed pixels, 8 pixels/byte
         * `a1r5g5b5` - 16-bit pixels, d[15]=a, d[14:10]=r, d[9:5]=g, d[4:0]=b
         * `a2r10g10b10` - 32-bit pixels, d[31:30]=a, d[29:20]=r, d[19:10]=g, d[9:0]=b
         * `a8b8g8r8` - 32-bit pixels, d[31:24]=a, d[23:16]=b, d[15:8]=g, d[7:0]=r
@@ -106,6 +107,7 @@ properties:
         * `x8r8g8b8` - 32-bit pixels, d[23:16]=r, d[15:8]=g, d[7:0]=b
         * `x8b8g8r8` - 32-bit pixels, d[23:16]=b, d[15:8]=g, d[7:0]=r
     enum:
+      - mono
       - a1r5g5b5
       - a2r10g10b10
       - a8b8g8r8
-- 
2.47.3