3 files changed, 196 insertions, 105 deletions

diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
index a8905049b9da..5c52307146c7 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
@@ -15,6 +15,7 @@
 #include <linux/err.h>
 #include <linux/clk.h>
 #include <linux/io.h>
+#include <linux/iopoll.h>
 #include <linux/interrupt.h>
 #include <linux/of.h>
 #include <linux/of_gpio.h>
@@ -35,6 +36,8 @@
 
 #define to_dp(nm)	container_of(nm, struct analogix_dp_device, nm)
 
+static const bool verify_fast_training;
+
 struct bridge_init {
 	struct i2c_client *client;
 	struct device_node *node;
@@ -98,20 +101,18 @@ static int analogix_dp_detect_hpd(struct analogix_dp_device *dp)
 	return 0;
 }
 
-int analogix_dp_psr_supported(struct device *dev)
+int analogix_dp_psr_enabled(struct analogix_dp_device *dp)
 {
-	struct analogix_dp_device *dp = dev_get_drvdata(dev);
 
-	return dp->psr_support;
+	return dp->psr_enable;
 }
-EXPORT_SYMBOL_GPL(analogix_dp_psr_supported);
+EXPORT_SYMBOL_GPL(analogix_dp_psr_enabled);
 
-int analogix_dp_enable_psr(struct device *dev)
+int analogix_dp_enable_psr(struct analogix_dp_device *dp)
 {
-	struct analogix_dp_device *dp = dev_get_drvdata(dev);
 	struct edp_vsc_psr psr_vsc;
 
-	if (!dp->psr_support)
+	if (!dp->psr_enable)
 		return 0;
 
 	/* Prepare VSC packet as per EDP 1.4 spec, Table 6.9 */
@@ -124,18 +125,16 @@ int analogix_dp_enable_psr(struct device *dev)
 	psr_vsc.DB0 = 0;
 	psr_vsc.DB1 = EDP_VSC_PSR_STATE_ACTIVE | EDP_VSC_PSR_CRC_VALUES_VALID;
 
-	analogix_dp_send_psr_spd(dp, &psr_vsc);
-	return 0;
+	return analogix_dp_send_psr_spd(dp, &psr_vsc, true);
 }
 EXPORT_SYMBOL_GPL(analogix_dp_enable_psr);
 
-int analogix_dp_disable_psr(struct device *dev)
+int analogix_dp_disable_psr(struct analogix_dp_device *dp)
 {
-	struct analogix_dp_device *dp = dev_get_drvdata(dev);
 	struct edp_vsc_psr psr_vsc;
 	int ret;
 
-	if (!dp->psr_support)
+	if (!dp->psr_enable)
 		return 0;
 
 	/* Prepare VSC packet as per EDP 1.4 spec, Table 6.9 */
@@ -152,8 +151,7 @@ int analogix_dp_disable_psr(struct device *dev)
 	if (ret != 1)
 		dev_err(dp->dev, "Failed to set DP Power0 %d\n", ret);
 
-	analogix_dp_send_psr_spd(dp, &psr_vsc);
-	return 0;
+	return analogix_dp_send_psr_spd(dp, &psr_vsc, false);
 }
 EXPORT_SYMBOL_GPL(analogix_dp_disable_psr);
 
@@ -533,7 +531,7 @@ static int analogix_dp_process_equalizer_training(struct analogix_dp_device *dp)
 {
 	int lane, lane_count, retval;
 	u32 reg;
-	u8 link_align, link_status[2], adjust_request[2];
+	u8 link_align, link_status[2], adjust_request[2], spread;
 
 	usleep_range(400, 401);
 
@@ -576,6 +574,20 @@ static int analogix_dp_process_equalizer_training(struct analogix_dp_device *dp)
 		dev_dbg(dp->dev, "final lane count = %.2x\n",
 			dp->link_train.lane_count);
 
+		retval = drm_dp_dpcd_readb(&dp->aux, DP_MAX_DOWNSPREAD,
+					   &spread);
+		if (retval != 1) {
+			dev_err(dp->dev, "failed to read downspread %d\n",
+				retval);
+			dp->fast_train_support = false;
+		} else {
+			dp->fast_train_support =
+				(spread & DP_NO_AUX_HANDSHAKE_LINK_TRAINING) ?
+					true : false;
+		}
+		dev_dbg(dp->dev, "fast link training %s\n",
+			dp->fast_train_support ? "supported" : "unsupported");
+
 		/* set enhanced mode if available */
 		analogix_dp_set_enhanced_mode(dp);
 		dp->link_train.lt_state = FINISHED;
@@ -632,10 +644,12 @@ static void analogix_dp_get_max_rx_lane_count(struct analogix_dp_device *dp,
 	*lane_count = DPCD_MAX_LANE_COUNT(data);
 }
 
-static void analogix_dp_init_training(struct analogix_dp_device *dp,
-				      enum link_lane_count_type max_lane,
-				      int max_rate)
+static int analogix_dp_full_link_train(struct analogix_dp_device *dp,
+				       u32 max_lanes, u32 max_rate)
 {
+	int retval = 0;
+	bool training_finished = false;
+
 	/*
 	 * MACRO_RST must be applied after the PLL_LOCK to avoid
 	 * the DP inter pair skew issue for at least 10 us
@@ -661,18 +675,13 @@ static void analogix_dp_init_training(struct analogix_dp_device *dp,
 	}
 
 	/* Setup TX lane count & rate */
-	if (dp->link_train.lane_count > max_lane)
-		dp->link_train.lane_count = max_lane;
+	if (dp->link_train.lane_count > max_lanes)
+		dp->link_train.lane_count = max_lanes;
 	if (dp->link_train.link_rate > max_rate)
 		dp->link_train.link_rate = max_rate;
 
 	/* All DP analog module power up */
 	analogix_dp_set_analog_power_down(dp, POWER_ALL, 0);
-}
-
-static int analogix_dp_sw_link_training(struct analogix_dp_device *dp)
-{
-	int retval = 0, training_finished = 0;
 
 	dp->link_train.lt_state = START;
 
@@ -707,27 +716,92 @@ static int analogix_dp_sw_link_training(struct analogix_dp_device *dp)
 	return retval;
 }
 
-static int analogix_dp_set_link_train(struct analogix_dp_device *dp,
-				      u32 count, u32 bwtype)
+static int analogix_dp_fast_link_train(struct analogix_dp_device *dp)
 {
-	int i;
-	int retval;
+	int i, ret;
+	u8 link_align, link_status[2];
+	enum pll_status status;
 
-	for (i = 0; i < DP_TIMEOUT_LOOP_COUNT; i++) {
-		analogix_dp_init_training(dp, count, bwtype);
-		retval = analogix_dp_sw_link_training(dp);
-		if (retval == 0)
-			break;
+	analogix_dp_reset_macro(dp);
+
+	analogix_dp_set_link_bandwidth(dp, dp->link_train.link_rate);
+	analogix_dp_set_lane_count(dp, dp->link_train.lane_count);
 
-		usleep_range(100, 110);
+	for (i = 0; i < dp->link_train.lane_count; i++) {
+		analogix_dp_set_lane_link_training(dp,
+			dp->link_train.training_lane[i], i);
 	}
 
-	return retval;
+	ret = readx_poll_timeout(analogix_dp_get_pll_lock_status, dp, status,
+				 status != PLL_UNLOCKED, 120,
+				 120 * DP_TIMEOUT_LOOP_COUNT);
+	if (ret) {
+		DRM_DEV_ERROR(dp->dev, "Wait for pll lock failed %d\n", ret);
+		return ret;
+	}
+
+	/* source Set training pattern 1 */
+	analogix_dp_set_training_pattern(dp, TRAINING_PTN1);
+	/* From DP spec, pattern must be on-screen for a minimum 500us */
+	usleep_range(500, 600);
+
+	analogix_dp_set_training_pattern(dp, TRAINING_PTN2);
+	/* From DP spec, pattern must be on-screen for a minimum 500us */
+	usleep_range(500, 600);
+
+	/* TODO: enhanced_mode?*/
+	analogix_dp_set_training_pattern(dp, DP_NONE);
+
+	/*
+	 * Useful for debugging issues with fast link training, disable for more
+	 * speed
+	 */
+	if (verify_fast_training) {
+		ret = drm_dp_dpcd_readb(&dp->aux, DP_LANE_ALIGN_STATUS_UPDATED,
+					&link_align);
+		if (ret < 0) {
+			DRM_DEV_ERROR(dp->dev, "Read align status failed %d\n",
+				      ret);
+			return ret;
+		}
+
+		ret = drm_dp_dpcd_read(&dp->aux, DP_LANE0_1_STATUS, link_status,
+				       2);
+		if (ret < 0) {
+			DRM_DEV_ERROR(dp->dev, "Read link status failed %d\n",
+				      ret);
+			return ret;
+		}
+
+		if (analogix_dp_clock_recovery_ok(link_status,
+						  dp->link_train.lane_count)) {
+			DRM_DEV_ERROR(dp->dev, "Clock recovery failed\n");
+			analogix_dp_reduce_link_rate(dp);
+			return -EIO;
+		}
+
+		if (analogix_dp_channel_eq_ok(link_status, link_align,
+					      dp->link_train.lane_count)) {
+			DRM_DEV_ERROR(dp->dev, "Channel EQ failed\n");
+			analogix_dp_reduce_link_rate(dp);
+			return -EIO;
+		}
+	}
+
+	return 0;
+}
+
+static int analogix_dp_train_link(struct analogix_dp_device *dp)
+{
+	if (dp->fast_train_support)
+		return analogix_dp_fast_link_train(dp);
+
+	return analogix_dp_full_link_train(dp, dp->video_info.max_lane_count,
+					   dp->video_info.max_link_rate);
 }
 
 static int analogix_dp_config_video(struct analogix_dp_device *dp)
 {
-	int retval = 0;
 	int timeout_loop = 0;
 	int done_count = 0;
 
@@ -783,10 +857,7 @@ static int analogix_dp_config_video(struct analogix_dp_device *dp)
 		usleep_range(1000, 1001);
 	}
 
-	if (retval != 0)
-		dev_err(dp->dev, "Video stream is not detected!\n");
-
-	return retval;
+	return 0;
 }
 
 static void analogix_dp_enable_scramble(struct analogix_dp_device *dp,
@@ -855,10 +926,10 @@ static void analogix_dp_commit(struct analogix_dp_device *dp)
 			DRM_ERROR("failed to disable the panel\n");
 	}
 
-	ret = analogix_dp_set_link_train(dp, dp->video_info.max_lane_count,
-					 dp->video_info.max_link_rate);
+	ret = readx_poll_timeout(analogix_dp_train_link, dp, ret, !ret, 100,
+				 DP_TIMEOUT_TRAINING_US * 5);
 	if (ret) {
-		dev_err(dp->dev, "unable to do link train\n");
+		dev_err(dp->dev, "unable to do link train, ret=%d\n", ret);
 		return;
 	}
 
@@ -880,8 +951,8 @@ static void analogix_dp_commit(struct analogix_dp_device *dp)
 	/* Enable video */
 	analogix_dp_start_video(dp);
 
-	dp->psr_support = analogix_dp_detect_sink_psr(dp);
-	if (dp->psr_support)
+	dp->psr_enable = analogix_dp_detect_sink_psr(dp);
+	if (dp->psr_enable)
 		analogix_dp_enable_sink_psr(dp);
 }
 
@@ -1019,27 +1090,30 @@ static int analogix_dp_bridge_attach(struct drm_bridge *bridge)
 {
 	struct analogix_dp_device *dp = bridge->driver_private;
 	struct drm_encoder *encoder = dp->encoder;
-	struct drm_connector *connector = &dp->connector;
-	int ret;
+	struct drm_connector *connector = NULL;
+	int ret = 0;
 
 	if (!bridge->encoder) {
 		DRM_ERROR("Parent encoder object not found");
 		return -ENODEV;
 	}
 
-	connector->polled = DRM_CONNECTOR_POLL_HPD;
+	if (!dp->plat_data->skip_connector) {
+		connector = &dp->connector;
+		connector->polled = DRM_CONNECTOR_POLL_HPD;
 
-	ret = drm_connector_init(dp->drm_dev, connector,
-				 &analogix_dp_connector_funcs,
-				 DRM_MODE_CONNECTOR_eDP);
-	if (ret) {
-		DRM_ERROR("Failed to initialize connector with drm\n");
-		return ret;
-	}
+		ret = drm_connector_init(dp->drm_dev, connector,
+					 &analogix_dp_connector_funcs,
+					 DRM_MODE_CONNECTOR_eDP);
+		if (ret) {
+			DRM_ERROR("Failed to initialize connector with drm\n");
+			return ret;
+		}
 
-	drm_connector_helper_add(connector,
-				 &analogix_dp_connector_helper_funcs);
-	drm_mode_connector_attach_encoder(connector, encoder);
+		drm_connector_helper_add(connector,
+					 &analogix_dp_connector_helper_funcs);
+		drm_mode_connector_attach_encoder(connector, encoder);
+	}
 
 	/*
 	 * NOTE: the connector registration is implemented in analogix
@@ -1123,6 +1197,7 @@ static void analogix_dp_bridge_disable(struct drm_bridge *bridge)
 	if (ret)
 		DRM_ERROR("failed to setup the panel ret = %d\n", ret);
 
+	dp->psr_enable = false;
 	dp->dpms_mode = DRM_MODE_DPMS_OFF;
 }
 
@@ -1283,8 +1358,9 @@ static ssize_t analogix_dpaux_transfer(struct drm_dp_aux *aux,
 	return analogix_dp_transfer(dp, msg);
 }
 
-int analogix_dp_bind(struct device *dev, struct drm_device *drm_dev,
-		     struct analogix_dp_plat_data *plat_data)
+struct analogix_dp_device *
+analogix_dp_bind(struct device *dev, struct drm_device *drm_dev,
+		 struct analogix_dp_plat_data *plat_data)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct analogix_dp_device *dp;
@@ -1294,14 +1370,12 @@ int analogix_dp_bind(struct device *dev, struct drm_device *drm_dev,
 
 	if (!plat_data) {
 		dev_err(dev, "Invalided input plat_data\n");
-		return -EINVAL;
+		return ERR_PTR(-EINVAL);
 	}
 
 	dp = devm_kzalloc(dev, sizeof(struct analogix_dp_device), GFP_KERNEL);
 	if (!dp)
-		return -ENOMEM;
-
-	dev_set_drvdata(dev, dp);
+		return ERR_PTR(-ENOMEM);
 
 	dp->dev = &pdev->dev;
 	dp->dpms_mode = DRM_MODE_DPMS_OFF;
@@ -1318,7 +1392,7 @@ int analogix_dp_bind(struct device *dev, struct drm_device *drm_dev,
 
 	ret = analogix_dp_dt_parse_pdata(dp);
 	if (ret)
-		return ret;
+		return ERR_PTR(ret);
 
 	dp->phy = devm_phy_get(dp->dev, "dp");
 	if (IS_ERR(dp->phy)) {
@@ -1332,14 +1406,14 @@ int analogix_dp_bind(struct device *dev, struct drm_device *drm_dev,
 			if (ret == -ENOSYS || ret == -ENODEV)
 				dp->phy = NULL;
 			else
-				return ret;
+				return ERR_PTR(ret);
 		}
 	}
 
 	dp->clock = devm_clk_get(&pdev->dev, "dp");
 	if (IS_ERR(dp->clock)) {
 		dev_err(&pdev->dev, "failed to get clock\n");
-		return PTR_ERR(dp->clock);
+		return ERR_CAST(dp->clock);
 	}
 
 	clk_prepare_enable(dp->clock);
@@ -1348,7 +1422,7 @@ int analogix_dp_bind(struct device *dev, struct drm_device *drm_dev,
 
 	dp->reg_base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(dp->reg_base))
-		return PTR_ERR(dp->reg_base);
+		return ERR_CAST(dp->reg_base);
 
 	dp->force_hpd = of_property_read_bool(dev->of_node, "force-hpd");
 
@@ -1369,7 +1443,7 @@ int analogix_dp_bind(struct device *dev, struct drm_device *drm_dev,
 					    "hpd_gpio");
 		if (ret) {
 			dev_err(&pdev->dev, "failed to get hpd gpio\n");
-			return ret;
+			return ERR_PTR(ret);
 		}
 		dp->irq = gpio_to_irq(dp->hpd_gpio);
 		irq_flags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
@@ -1381,16 +1455,9 @@ int analogix_dp_bind(struct device *dev, struct drm_device *drm_dev,
 
 	if (dp->irq == -ENXIO) {
 		dev_err(&pdev->dev, "failed to get irq\n");
-		return -ENODEV;
+		return ERR_PTR(-ENODEV);
 	}
 
-	pm_runtime_enable(dev);
-
-	pm_runtime_get_sync(dev);
-	phy_power_on(dp->phy);
-
-	analogix_dp_init_dp(dp);
-
 	ret = devm_request_threaded_irq(&pdev->dev, dp->irq,
 					analogix_dp_hardirq,
 					analogix_dp_irq_thread,
@@ -1410,38 +1477,30 @@ int analogix_dp_bind(struct device *dev, struct drm_device *drm_dev,
 
 	ret = drm_dp_aux_register(&dp->aux);
 	if (ret)
-		goto err_disable_pm_runtime;
+		return ERR_PTR(ret);
+
+	pm_runtime_enable(dev);
 
 	ret = analogix_dp_create_bridge(drm_dev, dp);
 	if (ret) {
 		DRM_ERROR("failed to create bridge (%d)\n", ret);
-		drm_encoder_cleanup(dp->encoder);
 		goto err_disable_pm_runtime;
 	}
 
-	phy_power_off(dp->phy);
-	pm_runtime_put(dev);
-
-	return 0;
+	return dp;
 
 err_disable_pm_runtime:
 
-	phy_power_off(dp->phy);
-	pm_runtime_put(dev);
 	pm_runtime_disable(dev);
 
-	return ret;
+	return ERR_PTR(ret);
 }
 EXPORT_SYMBOL_GPL(analogix_dp_bind);
 
-void analogix_dp_unbind(struct device *dev, struct device *master,
-			void *data)
+void analogix_dp_unbind(struct analogix_dp_device *dp)
 {
-	struct analogix_dp_device *dp = dev_get_drvdata(dev);
-
 	analogix_dp_bridge_disable(dp->bridge);
 	dp->connector.funcs->destroy(&dp->connector);
-	dp->encoder->funcs->destroy(dp->encoder);
 
 	if (dp->plat_data->panel) {
 		if (drm_panel_unprepare(dp->plat_data->panel))
@@ -1451,16 +1510,14 @@ void analogix_dp_unbind(struct device *dev, struct device *master,
 	}
 
 	drm_dp_aux_unregister(&dp->aux);
-	pm_runtime_disable(dev);
+	pm_runtime_disable(dp->dev);
 	clk_disable_unprepare(dp->clock);
 }
 EXPORT_SYMBOL_GPL(analogix_dp_unbind);
 
 #ifdef CONFIG_PM
-int analogix_dp_suspend(struct device *dev)
+int analogix_dp_suspend(struct analogix_dp_device *dp)
 {
-	struct analogix_dp_device *dp = dev_get_drvdata(dev);
-
 	clk_disable_unprepare(dp->clock);
 
 	if (dp->plat_data->panel) {
@@ -1472,9 +1529,8 @@ int analogix_dp_suspend(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(analogix_dp_suspend);
 
-int analogix_dp_resume(struct device *dev)
+int analogix_dp_resume(struct analogix_dp_device *dp)
 {
-	struct analogix_dp_device *dp = dev_get_drvdata(dev);
 	int ret;
 
 	ret = clk_prepare_enable(dp->clock);
diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h
index 5c6a28806129..6a96ef7e6934 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h
@@ -20,6 +20,10 @@
 #define MAX_CR_LOOP 5
 #define MAX_EQ_LOOP 5
 
+/* Training takes 22ms if AUX channel comm fails. Use this as retry interval */
+#define DP_TIMEOUT_TRAINING_US			22000
+#define DP_TIMEOUT_PSR_LOOP_MS			300
+
 /* DP_MAX_LANE_COUNT */
 #define DPCD_ENHANCED_FRAME_CAP(x)		(((x) >> 7) & 0x1)
 #define DPCD_MAX_LANE_COUNT(x)			((x) & 0x1f)
@@ -168,7 +172,8 @@ struct analogix_dp_device {
 	int			dpms_mode;
 	int			hpd_gpio;
 	bool                    force_hpd;
-	bool			psr_support;
+	bool			psr_enable;
+	bool			fast_train_support;
 
 	struct mutex		panel_lock;
 	bool			panel_is_modeset;
@@ -247,8 +252,8 @@ void analogix_dp_config_video_slave_mode(struct analogix_dp_device *dp);
 void analogix_dp_enable_scrambling(struct analogix_dp_device *dp);
 void analogix_dp_disable_scrambling(struct analogix_dp_device *dp);
 void analogix_dp_enable_psr_crc(struct analogix_dp_device *dp);
-void analogix_dp_send_psr_spd(struct analogix_dp_device *dp,
-			      struct edp_vsc_psr *vsc);
+int analogix_dp_send_psr_spd(struct analogix_dp_device *dp,
+			     struct edp_vsc_psr *vsc, bool blocking);
 ssize_t analogix_dp_transfer(struct analogix_dp_device *dp,
 			     struct drm_dp_aux_msg *msg);
 
diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
index 303083ad28e3..9df2f3ef000c 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
@@ -10,10 +10,11 @@
  * option) any later version.
  */
 
-#include <linux/device.h>
-#include <linux/io.h>
 #include <linux/delay.h>
+#include <linux/device.h>
 #include <linux/gpio.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
 
 #include <drm/bridge/analogix_dp.h>
 
@@ -992,10 +993,25 @@ void analogix_dp_enable_psr_crc(struct analogix_dp_device *dp)
 	writel(PSR_VID_CRC_ENABLE, dp->reg_base + ANALOGIX_DP_CRC_CON);
 }
 
-void analogix_dp_send_psr_spd(struct analogix_dp_device *dp,
-			      struct edp_vsc_psr *vsc)
+static ssize_t analogix_dp_get_psr_status(struct analogix_dp_device *dp)
+{
+	ssize_t val;
+	u8 status;
+
+	val = drm_dp_dpcd_readb(&dp->aux, DP_PSR_STATUS, &status);
+	if (val < 0) {
+		dev_err(dp->dev, "PSR_STATUS read failed ret=%zd", val);
+		return val;
+	}
+	return status;
+}
+
+int analogix_dp_send_psr_spd(struct analogix_dp_device *dp,
+			     struct edp_vsc_psr *vsc, bool blocking)
 {
 	unsigned int val;
+	int ret;
+	ssize_t psr_status;
 
 	/* don't send info frame */
 	val = readl(dp->reg_base + ANALOGIX_DP_PKT_SEND_CTL);
@@ -1036,6 +1052,20 @@ void analogix_dp_send_psr_spd(struct analogix_dp_device *dp,
 	val = readl(dp->reg_base + ANALOGIX_DP_PKT_SEND_CTL);
 	val |= IF_EN;
 	writel(val, dp->reg_base + ANALOGIX_DP_PKT_SEND_CTL);
+
+	if (!blocking)
+		return 0;
+
+	ret = readx_poll_timeout(analogix_dp_get_psr_status, dp, psr_status,
+		psr_status >= 0 &&
+		((vsc->DB1 && psr_status == DP_PSR_SINK_ACTIVE_RFB) ||
+		(!vsc->DB1 && psr_status == DP_PSR_SINK_INACTIVE)), 1500,
+		DP_TIMEOUT_PSR_LOOP_MS * 1000);
+	if (ret) {
+		dev_warn(dp->dev, "Failed to apply PSR %d\n", ret);
+		return ret;
+	}
+	return 0;
 }
 
 ssize_t analogix_dp_transfer(struct analogix_dp_device *dp,