Commit 2a6d731a authored by Rayyan Ansari's avatar Rayyan Ansari Committed by Thomas Zimmermann
Browse files

drm/simpledrm: Allow physical width and height configuration via panel node 



Parse the width-mm and height-mm devicetree properties of the panel node,
and use this to set the DRM Display Mode instead of calculating it
based on a hardcoded DPI.

Signed-off-by: default avatarRayyan Ansari <rayyan@ansari.sh>
Reviewed-by: default avatarThomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: default avatarThomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20230126182435.70544-2-rayyan@ansari.sh
parent 3524c96a

drivers/gpu/drm/tiny/simpledrm.c

+22 −9
Original line number Diff line number Diff line
@@ -606,16 +606,12 @@ static const struct drm_mode_config_funcs simpledrm_mode_config_funcs = { 
 */



static struct drm_display_mode simpledrm_mode(unsigned int width,

					      unsigned int height)

					      unsigned int height,

					      unsigned int width_mm,

					      unsigned int height_mm)

{

	/*

	 * Assume a monitor resolution of 96 dpi to

	 * get a somewhat reasonable screen size.

	 */

	const struct drm_display_mode mode = {

		DRM_MODE_INIT(60, width, height,

			      DRM_MODE_RES_MM(width, 96ul),

			      DRM_MODE_RES_MM(height, 96ul))

		DRM_MODE_INIT(60, width, height, width_mm, height_mm)

	};



	return mode;
@@ -629,6 +625,8 @@ static struct simpledrm_device *simpledrm_device_create(struct drm_driver *drv, 
	struct simpledrm_device *sdev;

	struct drm_device *dev;

	int width, height, stride;

	int width_mm = 0, height_mm = 0;

	struct device_node *panel_node;

	const struct drm_format_info *format;

	struct resource *res, *mem = NULL;

	struct drm_plane *primary_plane;
@@ -685,6 +683,12 @@ static struct simpledrm_device *simpledrm_device_create(struct drm_driver *drv, 
		mem = simplefb_get_memory_of(dev, of_node);

		if (IS_ERR(mem))

			return ERR_CAST(mem);

		panel_node = of_parse_phandle(of_node, "panel", 0);

		if (panel_node) {

			simplefb_read_u32_of(dev, panel_node, "width-mm", &width_mm);

			simplefb_read_u32_of(dev, panel_node, "height-mm", &height_mm);

			of_node_put(panel_node);

		}

	} else {

		drm_err(dev, "no simplefb configuration found\n");

		return ERR_PTR(-ENODEV);
@@ -695,7 +699,16 @@ static struct simpledrm_device *simpledrm_device_create(struct drm_driver *drv, 
			return ERR_PTR(-EINVAL);

	}



	sdev->mode = simpledrm_mode(width, height);

	/*

	 * Assume a monitor resolution of 96 dpi if physical dimensions

	 * are not specified to get a somewhat reasonable screen size.

	 */

	if (!width_mm)

		width_mm = DRM_MODE_RES_MM(width, 96ul);

	if (!height_mm)

		height_mm = DRM_MODE_RES_MM(height, 96ul);



	sdev->mode = simpledrm_mode(width, height, width_mm, height_mm);

	sdev->format = format;

	sdev->pitch = stride;