Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit b8a2948f authored by Sean Paul's avatar Sean Paul Committed by Sam Ravnborg
Browse files

drm/panel: simple: Add ability to override typical timing 



This patch adds the ability to override the typical display timing for a
given panel. This is useful for devices which have timing constraints
that do not apply across the entire display driver (eg: to avoid
crosstalk between panel and digitizer on certain laptops). The rules are
as follows:

- panel must not specify fixed mode (since the override mode will
  either be the same as the fixed mode, or we'll be unable to
  check the bounds of the overried)
- panel must specify at least one display_timing range which will be
  used to ensure the override mode fits within its bounds

Changes in v2:
 - Parse the full display-timings node (using the native-mode) (Rob)
Changes in v3:
 - No longer parse display-timings subnode, use panel-timing (Rob)
Changes in v4:
 - Don't add mode from timing if override was specified (Thierry)
 - Add warning if timing and fixed mode was specified (Thierry)
 - Don't add fixed mode if timing was specified (Thierry)
 - Refactor/rename a bit to avoid extra indentation from "if" tests
 - i should be unsigned (Thierry)
 - Add annoying WARN_ONs for some cases (Thierry)
 - Simplify 'No display_timing found' handling (Thierry)
 - Rename to panel_simple_parse_override_mode() (Thierry)
Changes in v5:
 - Added Heiko's Tested-by
Changes in v6:
 - Rebased to drm-misc next
 - Added tags

Cc: Doug Anderson <dianders@chromium.org>
Cc: Eric Anholt <eric@anholt.net>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Jeffy Chen <jeffy.chen@rock-chips.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Stéphane Marchesin <marcheu@chromium.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: devicetree@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: default avatarSean Paul <seanpaul@chromium.org>
Tested-by: default avatarEnric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: default avatarDouglas Anderson <dianders@chromium.org>
Tested-by: default avatarHeiko Stuebner <heiko@sntech.de>
Reviewed-by: default avatarBoris Brezillon <boris.brezillon@collabora.com>
Acked-by: default avatarThierry Reding <thierry.reding@gmail.com>
Signed-off-by: default avatarSam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190711203455.125667-2-dianders@chromium.org
parent a4e7e98e

drivers/gpu/drm/panel/panel-simple.c

+104 −5
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ 
#include <linux/regulator/consumer.h>



#include <video/display_timing.h>

#include <video/of_display_timing.h>

#include <video/videomode.h>



#include <drm/drm_crtc.h>
@@ -92,6 +93,8 @@ struct panel_simple { 
	struct i2c_adapter *ddc;



	struct gpio_desc *enable_gpio;



	struct drm_display_mode override_mode;

};



static inline struct panel_simple *to_panel_simple(struct drm_panel *panel)
@@ -99,16 +102,13 @@ static inline struct panel_simple *to_panel_simple(struct drm_panel *panel) 
	return container_of(panel, struct panel_simple, base);

}



static int panel_simple_get_fixed_modes(struct panel_simple *panel)

static unsigned int panel_simple_get_timings_modes(struct panel_simple *panel)

{

	struct drm_connector *connector = panel->base.connector;

	struct drm_device *drm = panel->base.drm;

	struct drm_display_mode *mode;

	unsigned int i, num = 0;



	if (!panel->desc)

		return 0;



	for (i = 0; i < panel->desc->num_timings; i++) {

		const struct display_timing *dt = &panel->desc->timings[i];

		struct videomode vm;
@@ -132,6 +132,16 @@ static int panel_simple_get_fixed_modes(struct panel_simple *panel) 
		num++;

	}



	return num;

}



static unsigned int panel_simple_get_fixed_modes(struct panel_simple *panel)

{

	struct drm_connector *connector = panel->base.connector;

	struct drm_device *drm = panel->base.drm;

	struct drm_display_mode *mode;

	unsigned int i, num = 0;



	for (i = 0; i < panel->desc->num_modes; i++) {

		const struct drm_display_mode *m = &panel->desc->modes[i];
@@ -153,6 +163,44 @@ static int panel_simple_get_fixed_modes(struct panel_simple *panel) 
		num++;

	}



	return num;

}



static int panel_simple_get_non_edid_modes(struct panel_simple *panel)

{

	struct drm_connector *connector = panel->base.connector;

	struct drm_device *drm = panel->base.drm;

	struct drm_display_mode *mode;

	bool has_override = panel->override_mode.type;

	unsigned int num = 0;



	if (!panel->desc)

		return 0;



	if (has_override) {

		mode = drm_mode_duplicate(drm, &panel->override_mode);

		if (mode) {

			drm_mode_probed_add(connector, mode);

			num = 1;

		} else {

			dev_err(drm->dev, "failed to add override mode\n");

		}

	}



	/* Only add timings if override was not there or failed to validate */

	if (num == 0 && panel->desc->num_timings)

		num = panel_simple_get_timings_modes(panel);



	/*

	 * Only add fixed modes if timings/override added no mode.

	 *

	 * We should only ever have either the display timings specified

	 * or a fixed mode. Anything else is rather bogus.

	 */

	WARN_ON(panel->desc->num_timings && panel->desc->num_modes);

	if (num == 0)

		num = panel_simple_get_fixed_modes(panel);



	connector->display_info.bpc = panel->desc->bpc;

	connector->display_info.width_mm = panel->desc->size.width;

	connector->display_info.height_mm = panel->desc->size.height;
@@ -269,7 +317,7 @@ static int panel_simple_get_modes(struct drm_panel *panel) 
	}



	/* add hard-coded panel modes */

	num += panel_simple_get_fixed_modes(p);

	num += panel_simple_get_non_edid_modes(p);



	return num;

}
@@ -300,10 +348,58 @@ static const struct drm_panel_funcs panel_simple_funcs = { 
	.get_timings = panel_simple_get_timings,

};



#define PANEL_SIMPLE_BOUNDS_CHECK(to_check, bounds, field) \

	(to_check->field.typ >= bounds->field.min && \

	 to_check->field.typ <= bounds->field.max)

static void panel_simple_parse_override_mode(struct device *dev,

					     struct panel_simple *panel,

					     const struct display_timing *ot)

{

	const struct panel_desc *desc = panel->desc;

	struct videomode vm;

	unsigned int i;



	if (WARN_ON(desc->num_modes)) {

		dev_err(dev, "Reject override mode: panel has a fixed mode\n");

		return;

	}

	if (WARN_ON(!desc->num_timings)) {

		dev_err(dev, "Reject override mode: no timings specified\n");

		return;

	}



	for (i = 0; i < panel->desc->num_timings; i++) {

		const struct display_timing *dt = &panel->desc->timings[i];



		if (!PANEL_SIMPLE_BOUNDS_CHECK(ot, dt, hactive) ||

		    !PANEL_SIMPLE_BOUNDS_CHECK(ot, dt, hfront_porch) ||

		    !PANEL_SIMPLE_BOUNDS_CHECK(ot, dt, hback_porch) ||

		    !PANEL_SIMPLE_BOUNDS_CHECK(ot, dt, hsync_len) ||

		    !PANEL_SIMPLE_BOUNDS_CHECK(ot, dt, vactive) ||

		    !PANEL_SIMPLE_BOUNDS_CHECK(ot, dt, vfront_porch) ||

		    !PANEL_SIMPLE_BOUNDS_CHECK(ot, dt, vback_porch) ||

		    !PANEL_SIMPLE_BOUNDS_CHECK(ot, dt, vsync_len))

			continue;



		if (ot->flags != dt->flags)

			continue;



		videomode_from_timing(ot, &vm);

		drm_display_mode_from_videomode(&vm, &panel->override_mode);

		panel->override_mode.type |= DRM_MODE_TYPE_DRIVER |

					     DRM_MODE_TYPE_PREFERRED;

		break;

	}



	if (WARN_ON(!panel->override_mode.type))

		dev_err(dev, "Reject override mode: No display_timing found\n");

}



static int panel_simple_probe(struct device *dev, const struct panel_desc *desc)

{

	struct device_node *backlight, *ddc;

	struct panel_simple *panel;

	struct display_timing dt;

	int err;



	panel = devm_kzalloc(dev, sizeof(*panel), GFP_KERNEL);
@@ -349,6 +445,9 @@ static int panel_simple_probe(struct device *dev, const struct panel_desc *desc) 
		}

	}



	if (!of_get_display_timing(dev->of_node, "panel-timing", &dt))

		panel_simple_parse_override_mode(dev, panel, &dt);



	drm_panel_init(&panel->base);

	panel->base.dev = dev;

	panel->base.funcs = &panel_simple_funcs;