1 files changed, 78 insertions, 48 deletions

diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
index b3d617505dda..48766b6abd29 100644
--- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c
+++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
@@ -32,7 +32,6 @@
 #include <drm/drm_edid.h>
 #include <drm/drm_mipi_dsi.h>
 #include <drm/drm_of.h>
-#include <drm/drm_panel.h>
 #include <drm/drm_print.h>
 #include <drm/drm_probe_helper.h>
 
@@ -196,7 +195,7 @@ struct ti_sn65dsi86 {
 	struct gpio_chip		gchip;
 	DECLARE_BITMAP(gchip_output, SN_NUM_GPIOS);
 #endif
-#if defined(CONFIG_PWM)
+#if IS_REACHABLE(CONFIG_PWM)
 	struct pwm_chip			*pchip;
 	bool				pwm_enabled;
 	atomic_t			pwm_pin_busy;
@@ -331,12 +330,18 @@ static void ti_sn65dsi86_enable_comms(struct ti_sn65dsi86 *pdata)
 	 * 200 ms.  We'll assume that the panel driver will have the hardcoded
 	 * delay in its prepare and always disable HPD.
 	 *
-	 * If HPD somehow makes sense on some future panel we'll have to
-	 * change this to be conditional on someone specifying that HPD should
-	 * be used.
+	 * For DisplayPort bridge type, we need HPD. So we use the bridge type
+	 * to conditionally disable HPD.
+	 * NOTE: The bridge type is set in ti_sn_bridge_probe() but enable_comms()
+	 * can be called before. So for DisplayPort, HPD will be enabled once
+	 * bridge type is set. We are using bridge type instead of "no-hpd"
+	 * property because it is not used properly in devicetree description
+	 * and hence is unreliable.
 	 */
-	regmap_update_bits(pdata->regmap, SN_HPD_DISABLE_REG, HPD_DISABLE,
-			   HPD_DISABLE);
+
+	if (pdata->bridge.type != DRM_MODE_CONNECTOR_DisplayPort)
+		regmap_update_bits(pdata->regmap, SN_HPD_DISABLE_REG, HPD_DISABLE,
+				   HPD_DISABLE);
 
 	pdata->comms_enabled = true;
 
@@ -424,36 +429,8 @@ static int status_show(struct seq_file *s, void *data)
 
 	return 0;
 }
-
 DEFINE_SHOW_ATTRIBUTE(status);
 
-static void ti_sn65dsi86_debugfs_remove(void *data)
-{
-	debugfs_remove_recursive(data);
-}
-
-static void ti_sn65dsi86_debugfs_init(struct ti_sn65dsi86 *pdata)
-{
-	struct device *dev = pdata->dev;
-	struct dentry *debugfs;
-	int ret;
-
-	debugfs = debugfs_create_dir(dev_name(dev), NULL);
-
-	/*
-	 * We might get an error back if debugfs wasn't enabled in the kernel
-	 * so let's just silently return upon failure.
-	 */
-	if (IS_ERR_OR_NULL(debugfs))
-		return;
-
-	ret = devm_add_action_or_reset(dev, ti_sn65dsi86_debugfs_remove, debugfs);
-	if (ret)
-		return;
-
-	debugfs_create_file("status", 0600, debugfs, pdata, &status_fops);
-}
-
 /* -----------------------------------------------------------------------------
  * Auxiliary Devices (*not* AUX)
  */
@@ -814,7 +791,7 @@ ti_sn_bridge_mode_valid(struct drm_bridge *bridge,
 }
 
 static void ti_sn_bridge_atomic_disable(struct drm_bridge *bridge,
-					struct drm_bridge_state *old_bridge_state)
+					struct drm_atomic_state *state)
 {
 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
 
@@ -1074,7 +1051,7 @@ exit:
 }
 
 static void ti_sn_bridge_atomic_enable(struct drm_bridge *bridge,
-				       struct drm_bridge_state *old_bridge_state)
+				       struct drm_atomic_state *state)
 {
 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
 	struct drm_connector *connector;
@@ -1086,7 +1063,7 @@ static void ti_sn_bridge_atomic_enable(struct drm_bridge *bridge,
 	int max_dp_lanes;
 	unsigned int bpp;
 
-	connector = drm_atomic_get_new_connector_for_encoder(old_bridge_state->base.state,
+	connector = drm_atomic_get_new_connector_for_encoder(state,
 							     bridge->encoder);
 	if (!connector) {
 		dev_err_ratelimited(pdata->dev, "Could not get the connector\n");
@@ -1165,7 +1142,7 @@ static void ti_sn_bridge_atomic_enable(struct drm_bridge *bridge,
 }
 
 static void ti_sn_bridge_atomic_pre_enable(struct drm_bridge *bridge,
-					   struct drm_bridge_state *old_bridge_state)
+					   struct drm_atomic_state *state)
 {
 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
 
@@ -1179,7 +1156,7 @@ static void ti_sn_bridge_atomic_pre_enable(struct drm_bridge *bridge,
 }
 
 static void ti_sn_bridge_atomic_post_disable(struct drm_bridge *bridge,
-					     struct drm_bridge_state *old_bridge_state)
+					     struct drm_atomic_state *state)
 {
 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
 
@@ -1201,9 +1178,14 @@ static enum drm_connector_status ti_sn_bridge_detect(struct drm_bridge *bridge)
 	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
 	int val = 0;
 
-	pm_runtime_get_sync(pdata->dev);
+	/*
+	 * Runtime reference is grabbed in ti_sn_bridge_hpd_enable()
+	 * as the chip won't report HPD just after being powered on.
+	 * HPD_DEBOUNCED_STATE reflects correct state only after the
+	 * debounce time (~100-400 ms).
+	 */
+
 	regmap_read(pdata->regmap, SN_HPD_DISABLE_REG, &val);
-	pm_runtime_put_autosuspend(pdata->dev);
 
 	return val & HPD_DEBOUNCED_STATE ? connector_status_connected
 					 : connector_status_disconnected;
@@ -1217,6 +1199,35 @@ static const struct drm_edid *ti_sn_bridge_edid_read(struct drm_bridge *bridge,
 	return drm_edid_read_ddc(connector, &pdata->aux.ddc);
 }
 
+static void ti_sn65dsi86_debugfs_init(struct drm_bridge *bridge, struct dentry *root)
+{
+	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
+	struct dentry *debugfs;
+
+	debugfs = debugfs_create_dir(dev_name(pdata->dev), root);
+	debugfs_create_file("status", 0600, debugfs, pdata, &status_fops);
+}
+
+static void ti_sn_bridge_hpd_enable(struct drm_bridge *bridge)
+{
+	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
+
+	/*
+	 * Device needs to be powered on before reading the HPD state
+	 * for reliable hpd detection in ti_sn_bridge_detect() due to
+	 * the high debounce time.
+	 */
+
+	pm_runtime_get_sync(pdata->dev);
+}
+
+static void ti_sn_bridge_hpd_disable(struct drm_bridge *bridge)
+{
+	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
+
+	pm_runtime_put_autosuspend(pdata->dev);
+}
+
 static const struct drm_bridge_funcs ti_sn_bridge_funcs = {
 	.attach = ti_sn_bridge_attach,
 	.detach = ti_sn_bridge_detach,
@@ -1230,6 +1241,9 @@ static const struct drm_bridge_funcs ti_sn_bridge_funcs = {
 	.atomic_reset = drm_atomic_helper_bridge_reset,
 	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
 	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
+	.debugfs_init = ti_sn65dsi86_debugfs_init,
+	.hpd_enable = ti_sn_bridge_hpd_enable,
+	.hpd_disable = ti_sn_bridge_hpd_disable,
 };
 
 static void ti_sn_bridge_parse_lanes(struct ti_sn65dsi86 *pdata,
@@ -1318,8 +1332,26 @@ static int ti_sn_bridge_probe(struct auxiliary_device *adev,
 	pdata->bridge.type = pdata->next_bridge->type == DRM_MODE_CONNECTOR_DisplayPort
 			   ? DRM_MODE_CONNECTOR_DisplayPort : DRM_MODE_CONNECTOR_eDP;
 
-	if (pdata->bridge.type == DRM_MODE_CONNECTOR_DisplayPort)
-		pdata->bridge.ops = DRM_BRIDGE_OP_EDID | DRM_BRIDGE_OP_DETECT;
+	if (pdata->bridge.type == DRM_MODE_CONNECTOR_DisplayPort) {
+		pdata->bridge.ops = DRM_BRIDGE_OP_EDID | DRM_BRIDGE_OP_DETECT |
+				    DRM_BRIDGE_OP_HPD;
+		/*
+		 * If comms were already enabled they would have been enabled
+		 * with the wrong value of HPD_DISABLE. Update it now. Comms
+		 * could be enabled if anyone is holding a pm_runtime reference
+		 * (like if a GPIO is in use). Note that in most cases nobody
+		 * is doing AUX channel xfers before the bridge is added so
+		 * HPD doesn't _really_ matter then. The only exception is in
+		 * the eDP case where the panel wants to read the EDID before
+		 * the bridge is added. We always consistently have HPD disabled
+		 * for eDP.
+		 */
+		mutex_lock(&pdata->comms_mutex);
+		if (pdata->comms_enabled)
+			regmap_update_bits(pdata->regmap, SN_HPD_DISABLE_REG,
+					   HPD_DISABLE, 0);
+		mutex_unlock(&pdata->comms_mutex);
+	}
 
 	drm_bridge_add(&pdata->bridge);
 
@@ -1363,7 +1395,7 @@ static struct auxiliary_driver ti_sn_bridge_driver = {
 /* -----------------------------------------------------------------------------
  * PWM Controller
  */
-#if defined(CONFIG_PWM)
+#if IS_REACHABLE(CONFIG_PWM)
 static int ti_sn_pwm_pin_request(struct ti_sn65dsi86 *pdata)
 {
 	return atomic_xchg(&pdata->pwm_pin_busy, 1) ? -EBUSY : 0;
@@ -1938,8 +1970,6 @@ static int ti_sn65dsi86_probe(struct i2c_client *client)
 	if (ret)
 		return ret;
 
-	ti_sn65dsi86_debugfs_init(pdata);
-
 	/*
 	 * Break ourselves up into a collection of aux devices. The only real
 	 * motiviation here is to solve the chicken-and-egg problem of probe
@@ -1957,7 +1987,7 @@ static int ti_sn65dsi86_probe(struct i2c_client *client)
 			return ret;
 	}
 
-	if (IS_ENABLED(CONFIG_PWM)) {
+	if (IS_REACHABLE(CONFIG_PWM)) {
 		ret = ti_sn65dsi86_add_aux_device(pdata, &pdata->pwm_aux, "pwm");
 		if (ret)
 			return ret;