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: Laurent Pinchart laurent.pinchart+renesas@ideasonboard.com Reviewed-by: Jacopo Mondi jacopo+renesas@jmondi.org --- drivers/gpu/drm/rcar-du/rcar_lvds.c | 104 ++++++++++++++++++++++++---- drivers/gpu/drm/rcar-du/rcar_lvds.h | 5 ++ 2 files changed, 96 insertions(+), 13 deletions(-)
diff --git a/drivers/gpu/drm/rcar-du/rcar_lvds.c b/drivers/gpu/drm/rcar-du/rcar_lvds.c index a331f0c32187..f7e4710fe33f 100644 --- a/drivers/gpu/drm/rcar-du/rcar_lvds.c +++ b/drivers/gpu/drm/rcar-du/rcar_lvds.c @@ -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. */ - lvds->info->pll_setup(lvds, mode->clock * 1000); + /* + * 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) - lvdcr0 |= LVDCR0_DUSEL; + + 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 +650,54 @@ 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) + return -ENODEV; + + /* + * 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)) { + ret = -ENODEV; + 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; @@ -682,14 +748,26 @@ 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); of_node_put(remote_input); diff --git a/drivers/gpu/drm/rcar-du/rcar_lvds.h b/drivers/gpu/drm/rcar-du/rcar_lvds.h index a709cae1bc32..222ec0e60785 100644 --- a/drivers/gpu/drm/rcar-du/rcar_lvds.h +++ b/drivers/gpu/drm/rcar-du/rcar_lvds.h @@ -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__ */