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

Commit fa440d87 authored by Laurent Pinchart's avatar Laurent Pinchart
Browse files

drm: rcar-du: lvds: Add support for dual-link mode 



In dual-link mode the LVDS0 encoder transmits even-numbered pixels, and
sends odd-numbered pixels to the LVDS1 encoder for transmission on a
separate link.

To implement support for this mode of operation, determine if the LVDS
connection operates in dual-link mode by querying the next device in the
pipeline, locate the companion encoder, and control it directly through
its bridge operations.

Signed-off-by: default avatarLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: default avatarJacopo Mondi <jacopo+renesas@jmondi.org>
Tested-by: default avatarJacopo Mondi <jacopo+renesas@jmondi.org>
Acked-by: default avatarSam Ravnborg <sam@ravnborg.org>
Reviewed-by: default avatarKieran Bingham <kieran.bingham+renesas@ideasonboard.com>
parent 96832849

drivers/gpu/drm/rcar-du/rcar_lvds.c

+94 −13
Original line number Diff line number Diff line
@@ -66,6 +66,9 @@ struct rcar_lvds { 


	struct drm_display_mode display_mode;

	enum rcar_lvds_mode mode;



	struct drm_bridge *companion;

	bool dual_link;

};



#define bridge_to_rcar_lvds(bridge) \
@@ -400,11 +403,6 @@ static void rcar_lvds_enable(struct drm_bridge *bridge) 
{

	struct rcar_lvds *lvds = bridge_to_rcar_lvds(bridge);

	const struct drm_display_mode *mode = &lvds->display_mode;

	/*

	 * FIXME: We should really retrieve the CRTC through the state, but how

	 * do we get a state pointer?

	 */

	struct drm_crtc *crtc = lvds->bridge.encoder->crtc;

	u32 lvdhcr;

	u32 lvdcr0;

	int ret;
@@ -413,6 +411,10 @@ static void rcar_lvds_enable(struct drm_bridge *bridge) 
	if (ret < 0)

		return;



	/* Enable the companion LVDS encoder in dual-link mode. */

	if (lvds->dual_link && lvds->companion)

		lvds->companion->funcs->enable(lvds->companion);



	/*

	 * Hardcode the channels and control signals routing for now.

	 *
@@ -435,17 +437,33 @@ static void rcar_lvds_enable(struct drm_bridge *bridge) 
	rcar_lvds_write(lvds, LVDCHCR, lvdhcr);



	if (lvds->info->quirks & RCAR_LVDS_QUIRK_DUAL_LINK) {

		/* Disable dual-link mode. */

		rcar_lvds_write(lvds, LVDSTRIPE, 0);

		/*

		 * Configure vertical stripe based on the mode of operation of

		 * the connected device.

		 */

		rcar_lvds_write(lvds, LVDSTRIPE,

				lvds->dual_link ? LVDSTRIPE_ST_ON : 0);

	}



	/* PLL clock configuration. */

	/*

	 * PLL clock configuration on all instances but the companion in

	 * dual-link mode.

	 */

	if (!lvds->dual_link || lvds->companion)

		lvds->info->pll_setup(lvds, mode->clock * 1000);



	/* Set the LVDS mode and select the input. */

	lvdcr0 = lvds->mode << LVDCR0_LVMD_SHIFT;

	if (drm_crtc_index(crtc) == 2)



	if (lvds->bridge.encoder) {

		/*

		 * FIXME: We should really retrieve the CRTC through the state,

		 * but how do we get a state pointer?

		 */

		if (drm_crtc_index(lvds->bridge.encoder->crtc) == 2)

			lvdcr0 |= LVDCR0_DUSEL;

	}



	rcar_lvds_write(lvds, LVDCR0, lvdcr0);



	/* Turn all the channels on. */
@@ -512,6 +530,10 @@ static void rcar_lvds_disable(struct drm_bridge *bridge) 
	rcar_lvds_write(lvds, LVDCR1, 0);

	rcar_lvds_write(lvds, LVDPLLCR, 0);



	/* Disable the companion LVDS encoder in dual-link mode. */

	if (lvds->dual_link && lvds->companion)

		lvds->companion->funcs->disable(lvds->companion);



	clk_disable_unprepare(lvds->clocks.mod);

}
@@ -628,10 +650,57 @@ static const struct drm_bridge_funcs rcar_lvds_bridge_ops = { 
	.mode_set = rcar_lvds_mode_set,

};



bool rcar_lvds_dual_link(struct drm_bridge *bridge)

{

	struct rcar_lvds *lvds = bridge_to_rcar_lvds(bridge);



	return lvds->dual_link;

}

EXPORT_SYMBOL_GPL(rcar_lvds_dual_link);



/* -----------------------------------------------------------------------------

 * Probe & Remove

 */



static int rcar_lvds_parse_dt_companion(struct rcar_lvds *lvds)

{

	const struct of_device_id *match;

	struct device_node *companion;

	struct device *dev = lvds->dev;

	int ret = 0;



	/* Locate the companion LVDS encoder for dual-link operation, if any. */

	companion = of_parse_phandle(dev->of_node, "renesas,companion", 0);

	if (!companion) {

		dev_err(dev, "Companion LVDS encoder not found\n");

		return -ENXIO;

	}



	/*

	 * Sanity check: the companion encoder must have the same compatible

	 * string.

	 */

	match = of_match_device(dev->driver->of_match_table, dev);

	if (!of_device_is_compatible(companion, match->compatible)) {

		dev_err(dev, "Companion LVDS encoder is invalid\n");

		ret = -ENXIO;

		goto done;

	}



	lvds->companion = of_drm_find_bridge(companion);

	if (!lvds->companion) {

		ret = -EPROBE_DEFER;

		goto done;

	}



	dev_dbg(dev, "Found companion encoder %pOF\n", companion);



done:

	of_node_put(companion);



	return ret;

}



static int rcar_lvds_parse_dt(struct rcar_lvds *lvds)

{

	struct device_node *local_output = NULL;
@@ -682,13 +751,25 @@ static int rcar_lvds_parse_dt(struct rcar_lvds *lvds) 


	if (is_bridge) {

		lvds->next_bridge = of_drm_find_bridge(remote);

		if (!lvds->next_bridge)

		if (!lvds->next_bridge) {

			ret = -EPROBE_DEFER;

			goto done;

		}



		if (lvds->info->quirks & RCAR_LVDS_QUIRK_DUAL_LINK)

			lvds->dual_link = lvds->next_bridge->timings

					? lvds->next_bridge->timings->dual_link

					: false;

	} else {

		lvds->panel = of_drm_find_panel(remote);

		if (IS_ERR(lvds->panel))

		if (IS_ERR(lvds->panel)) {

			ret = PTR_ERR(lvds->panel);

			goto done;

		}

	}



	if (lvds->dual_link)

		ret = rcar_lvds_parse_dt_companion(lvds);



done:

	of_node_put(local_output);

drivers/gpu/drm/rcar-du/rcar_lvds.h

+5 −0
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ struct drm_bridge; 
#if IS_ENABLED(CONFIG_DRM_RCAR_LVDS)

int rcar_lvds_clk_enable(struct drm_bridge *bridge, unsigned long freq);

void rcar_lvds_clk_disable(struct drm_bridge *bridge);

bool rcar_lvds_dual_link(struct drm_bridge *bridge);

#else

static inline int rcar_lvds_clk_enable(struct drm_bridge *bridge,

				       unsigned long freq)
@@ -22,6 +23,10 @@ static inline int rcar_lvds_clk_enable(struct drm_bridge *bridge, 
	return -ENOSYS;

}

static inline void rcar_lvds_clk_disable(struct drm_bridge *bridge) { }

static inline bool rcar_lvds_dual_link(struct drm_bridge *bridge)

{

	return false;

}

#endif /* CONFIG_DRM_RCAR_LVDS */



#endif /* __RCAR_LVDS_H__ */