drm/msm: Initial add eDP support in msm drm driver (v5)

This change adds a new eDP connector in msm drm driver. With this
change, eDP panel can work with msm platform under drm framework.

v1: Initial change

v2: Address Rob's comments
Use generated header file for register definitions
Change to devm_* APIs

v3: Address Thierry's comments and rebase on top of atomic changes
Remove edp_bridge_mode_fixup
Remove backlight control code and rely on pwm-backlight
Remove continuous splash screen support for now
Change to gpiod_* APIs

v4: Fix kbuild test issue

Signed-off-by: Hai Li <[e-mail]>
[robclark: v5: rebase on drm_bridge changes in drm-next]
Signed-off-by: Rob Clark <[e-mail]>

drivers/gpu/drm/msm/Makefile

···
 	hdmi/hdmi_phy_8960.o \
 	hdmi/hdmi_phy_8x60.o \
 	hdmi/hdmi_phy_8x74.o \
+	edp/edp.o \
+	edp/edp_aux.o \
+	edp/edp_bridge.o \
+	edp/edp_connector.o \
+	edp/edp_ctrl.o \
+	edp/edp_phy.o \
 	mdp/mdp_format.o \
 	mdp/mdp_kms.o \
 	mdp/mdp4/mdp4_crtc.o \

drivers/gpu/drm/msm/edp/edp.c

···
+/*
+ * Copyright (c) 2014-2015, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/of_irq.h>
+#include "edp.h"
+
+static irqreturn_t edp_irq(int irq, void *dev_id)
+{
+	struct msm_edp *edp = dev_id;
+
+	/* Process eDP irq */
+	return msm_edp_ctrl_irq(edp->ctrl);
+}
+
+static void edp_destroy(struct platform_device *pdev)
+{
+	struct msm_edp *edp = platform_get_drvdata(pdev);
+
+	if (!edp)
+		return;
+
+	if (edp->ctrl) {
+		msm_edp_ctrl_destroy(edp->ctrl);
+		edp->ctrl = NULL;
+	}
+
+	platform_set_drvdata(pdev, NULL);
+}
+
+/* construct eDP at bind/probe time, grab all the resources. */
+static struct msm_edp *edp_init(struct platform_device *pdev)
+{
+	struct msm_edp *edp = NULL;
+	int ret;
+
+	if (!pdev) {
+		pr_err("no eDP device\n");
+		ret = -ENXIO;
+		goto fail;
+	}
+
+	edp = devm_kzalloc(&pdev->dev, sizeof(*edp), GFP_KERNEL);
+	if (!edp) {
+		ret = -ENOMEM;
+		goto fail;
+	}
+	DBG("eDP probed=%p", edp);
+
+	edp->pdev = pdev;
+	platform_set_drvdata(pdev, edp);
+
+	ret = msm_edp_ctrl_init(edp);
+	if (ret)
+		goto fail;
+
+	return edp;
+
+fail:
+	if (edp)
+		edp_destroy(pdev);
+
+	return ERR_PTR(ret);
+}
+
+static int edp_bind(struct device *dev, struct device *master, void *data)
+{
+	struct drm_device *drm = dev_get_drvdata(master);
+	struct msm_drm_private *priv = drm->dev_private;
+	struct msm_edp *edp;
+
+	DBG("");
+	edp = edp_init(to_platform_device(dev));
+	if (IS_ERR(edp))
+		return PTR_ERR(edp);
+	priv->edp = edp;
+
+	return 0;
+}
+
+static void edp_unbind(struct device *dev, struct device *master, void *data)
+{
+	struct drm_device *drm = dev_get_drvdata(master);
+	struct msm_drm_private *priv = drm->dev_private;
+
+	DBG("");
+	if (priv->edp) {
+		edp_destroy(to_platform_device(dev));
+		priv->edp = NULL;
+	}
+}
+
+static const struct component_ops edp_ops = {
+		.bind   = edp_bind,
+		.unbind = edp_unbind,
+};
+
+static int edp_dev_probe(struct platform_device *pdev)
+{
+	DBG("");
+	return component_add(&pdev->dev, &edp_ops);
+}
+
+static int edp_dev_remove(struct platform_device *pdev)
+{
+	DBG("");
+	component_del(&pdev->dev, &edp_ops);
+	return 0;
+}
+
+static const struct of_device_id dt_match[] = {
+	{ .compatible = "qcom,mdss-edp" },
+	{}
+};
+
+static struct platform_driver edp_driver = {
+	.probe = edp_dev_probe,
+	.remove = edp_dev_remove,
+	.driver = {
+		.name = "msm_edp",
+		.of_match_table = dt_match,
+	},
+};
+
+void __init msm_edp_register(void)
+{
+	DBG("");
+	platform_driver_register(&edp_driver);
+}
+
+void __exit msm_edp_unregister(void)
+{
+	DBG("");
+	platform_driver_unregister(&edp_driver);
+}
+
+/* Second part of initialization, the drm/kms level modeset_init */
+int msm_edp_modeset_init(struct msm_edp *edp, struct drm_device *dev,
+				struct drm_encoder *encoder)
+{
+	struct platform_device *pdev = edp->pdev;
+	struct msm_drm_private *priv = dev->dev_private;
+	int ret;
+
+	edp->encoder = encoder;
+	edp->dev = dev;
+
+	edp->bridge = msm_edp_bridge_init(edp);
+	if (IS_ERR(edp->bridge)) {
+		ret = PTR_ERR(edp->bridge);
+		dev_err(dev->dev, "failed to create eDP bridge: %d\n", ret);
+		edp->bridge = NULL;
+		goto fail;
+	}
+
+	edp->connector = msm_edp_connector_init(edp);
+	if (IS_ERR(edp->connector)) {
+		ret = PTR_ERR(edp->connector);
+		dev_err(dev->dev, "failed to create eDP connector: %d\n", ret);
+		edp->connector = NULL;
+		goto fail;
+	}
+
+	edp->irq = irq_of_parse_and_map(pdev->dev.of_node, 0);
+	if (edp->irq < 0) {
+		ret = edp->irq;
+		dev_err(dev->dev, "failed to get IRQ: %d\n", ret);
+		goto fail;
+	}
+
+	ret = devm_request_irq(&pdev->dev, edp->irq,
+			edp_irq, IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
+			"edp_isr", edp);
+	if (ret < 0) {
+		dev_err(dev->dev, "failed to request IRQ%u: %d\n",
+				edp->irq, ret);
+		goto fail;
+	}
+
+	encoder->bridge = edp->bridge;
+
+	priv->bridges[priv->num_bridges++]       = edp->bridge;
+	priv->connectors[priv->num_connectors++] = edp->connector;
+
+	return 0;
+
+fail:
+	/* bridge/connector are normally destroyed by drm */
+	if (edp->bridge) {
+		edp_bridge_destroy(edp->bridge);
+		edp->bridge = NULL;
+	}
+	if (edp->connector) {
+		edp->connector->funcs->destroy(edp->connector);
+		edp->connector = NULL;
+	}
+
+	return ret;
+}

drivers/gpu/drm/msm/edp/edp.h

···
+/*
+ * Copyright (c) 2014-2015, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef __EDP_CONNECTOR_H__
+#define __EDP_CONNECTOR_H__
+
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+
+#include "drm_crtc.h"
+#include "drm_dp_helper.h"
+#include "msm_drv.h"
+
+#define edp_read(offset) msm_readl((offset))
+#define edp_write(offset, data) msm_writel((data), (offset))
+
+struct edp_ctrl;
+struct edp_aux;
+struct edp_phy;
+
+struct msm_edp {
+	struct drm_device *dev;
+	struct platform_device *pdev;
+
+	struct drm_connector *connector;
+	struct drm_bridge *bridge;
+
+	/* the encoder we are hooked to (outside of eDP block) */
+	struct drm_encoder *encoder;
+
+	struct edp_ctrl *ctrl;
+
+	int irq;
+};
+
+/* eDP bridge */
+struct drm_bridge *msm_edp_bridge_init(struct msm_edp *edp);
+void edp_bridge_destroy(struct drm_bridge *bridge);
+
+/* eDP connector */
+struct drm_connector *msm_edp_connector_init(struct msm_edp *edp);
+
+/* AUX */
+void *msm_edp_aux_init(struct device *dev, void __iomem *regbase,
+			struct drm_dp_aux **drm_aux);
+void msm_edp_aux_destroy(struct device *dev, struct edp_aux *aux);
+irqreturn_t msm_edp_aux_irq(struct edp_aux *aux, u32 isr);
+void msm_edp_aux_ctrl(struct edp_aux *aux, int enable);
+
+/* Phy */
+bool msm_edp_phy_ready(struct edp_phy *phy);
+void msm_edp_phy_ctrl(struct edp_phy *phy, int enable);
+void msm_edp_phy_vm_pe_init(struct edp_phy *phy);
+void msm_edp_phy_vm_pe_cfg(struct edp_phy *phy, u32 v0, u32 v1);
+void msm_edp_phy_lane_power_ctrl(struct edp_phy *phy, bool up, u32 max_lane);
+void *msm_edp_phy_init(struct device *dev, void __iomem *regbase);
+
+/* Ctrl */
+irqreturn_t msm_edp_ctrl_irq(struct edp_ctrl *ctrl);
+void msm_edp_ctrl_power(struct edp_ctrl *ctrl, bool on);
+int msm_edp_ctrl_init(struct msm_edp *edp);
+void msm_edp_ctrl_destroy(struct edp_ctrl *ctrl);
+bool msm_edp_ctrl_panel_connected(struct edp_ctrl *ctrl);
+int msm_edp_ctrl_get_panel_info(struct edp_ctrl *ctrl,
+	struct drm_connector *connector, struct edid **edid);
+int msm_edp_ctrl_timing_cfg(struct edp_ctrl *ctrl,
+				const struct drm_display_mode *mode,
+				const struct drm_display_info *info);
+/* @pixel_rate is in kHz */
+bool msm_edp_ctrl_pixel_clock_valid(struct edp_ctrl *ctrl,
+	u32 pixel_rate, u32 *pm, u32 *pn);
+
+#endif /* __EDP_CONNECTOR_H__ */

drivers/gpu/drm/msm/edp/edp_aux.c

···
+/*
+ * Copyright (c) 2014-2015, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include "edp.h"
+#include "edp.xml.h"
+
+#define AUX_CMD_FIFO_LEN	144
+#define AUX_CMD_NATIVE_MAX	16
+#define AUX_CMD_I2C_MAX		128
+
+#define EDP_INTR_AUX_I2C_ERR	\
+	(EDP_INTERRUPT_REG_1_WRONG_ADDR | EDP_INTERRUPT_REG_1_TIMEOUT | \
+	EDP_INTERRUPT_REG_1_NACK_DEFER | EDP_INTERRUPT_REG_1_WRONG_DATA_CNT | \
+	EDP_INTERRUPT_REG_1_I2C_NACK | EDP_INTERRUPT_REG_1_I2C_DEFER)
+#define EDP_INTR_TRANS_STATUS	\
+	(EDP_INTERRUPT_REG_1_AUX_I2C_DONE | EDP_INTR_AUX_I2C_ERR)
+
+struct edp_aux {
+	void __iomem *base;
+	bool msg_err;
+
+	struct completion msg_comp;
+
+	/* To prevent the message transaction routine from reentry. */
+	struct mutex msg_mutex;
+
+	struct drm_dp_aux drm_aux;
+};
+#define to_edp_aux(x) container_of(x, struct edp_aux, drm_aux)
+
+static int edp_msg_fifo_tx(struct edp_aux *aux, struct drm_dp_aux_msg *msg)
+{
+	u32 data[4];
+	u32 reg, len;
+	bool native = msg->request & (DP_AUX_NATIVE_WRITE & DP_AUX_NATIVE_READ);
+	bool read = msg->request & (DP_AUX_I2C_READ & DP_AUX_NATIVE_READ);
+	u8 *msgdata = msg->buffer;
+	int i;
+
+	if (read)
+		len = 4;
+	else
+		len = msg->size + 4;
+
+	/*
+	 * cmd fifo only has depth of 144 bytes
+	 */
+	if (len > AUX_CMD_FIFO_LEN)
+		return -EINVAL;
+
+	/* Pack cmd and write to HW */
+	data[0] = (msg->address >> 16) & 0xf;	/* addr[19:16] */
+	if (read)
+		data[0] |=  BIT(4);		/* R/W */
+
+	data[1] = (msg->address >> 8) & 0xff;	/* addr[15:8] */
+	data[2] = msg->address & 0xff;		/* addr[7:0] */
+	data[3] = (msg->size - 1) & 0xff;	/* len[7:0] */
+
+	for (i = 0; i < len; i++) {
+		reg = (i < 4) ? data[i] : msgdata[i - 4];
+		reg = EDP_AUX_DATA_DATA(reg); /* index = 0, write */
+		if (i == 0)
+			reg |= EDP_AUX_DATA_INDEX_WRITE;
+		edp_write(aux->base + REG_EDP_AUX_DATA, reg);
+	}
+
+	reg = 0; /* Transaction number is always 1 */
+	if (!native) /* i2c */
+		reg |= EDP_AUX_TRANS_CTRL_I2C;
+
+	reg |= EDP_AUX_TRANS_CTRL_GO;
+	edp_write(aux->base + REG_EDP_AUX_TRANS_CTRL, reg);
+
+	return 0;
+}
+
+static int edp_msg_fifo_rx(struct edp_aux *aux, struct drm_dp_aux_msg *msg)
+{
+	u32 data;
+	u8 *dp;
+	int i;
+	u32 len = msg->size;
+
+	edp_write(aux->base + REG_EDP_AUX_DATA,
+		EDP_AUX_DATA_INDEX_WRITE | EDP_AUX_DATA_READ); /* index = 0 */
+
+	dp = msg->buffer;
+
+	/* discard first byte */
+	data = edp_read(aux->base + REG_EDP_AUX_DATA);
+	for (i = 0; i < len; i++) {
+		data = edp_read(aux->base + REG_EDP_AUX_DATA);
+		dp[i] = (u8)((data >> 8) & 0xff);
+	}
+
+	return 0;
+}
+
+/*
+ * This function does the real job to process an AUX transaction.
+ * It will call msm_edp_aux_ctrl() function to reset the AUX channel,
+ * if the waiting is timeout.
+ * The caller who triggers the transaction should avoid the
+ * msm_edp_aux_ctrl() running concurrently in other threads, i.e.
+ * start transaction only when AUX channel is fully enabled.
+ */
+ssize_t edp_aux_transfer(struct drm_dp_aux *drm_aux, struct drm_dp_aux_msg *msg)
+{
+	struct edp_aux *aux = to_edp_aux(drm_aux);
+	ssize_t ret;
+	bool native = msg->request & (DP_AUX_NATIVE_WRITE & DP_AUX_NATIVE_READ);
+	bool read = msg->request & (DP_AUX_I2C_READ & DP_AUX_NATIVE_READ);
+
+	/* Ignore address only message */
+	if ((msg->size == 0) || (msg->buffer == NULL)) {
+		msg->reply = native ?
+			DP_AUX_NATIVE_REPLY_ACK : DP_AUX_I2C_REPLY_ACK;
+		return msg->size;
+	}
+
+	/* msg sanity check */
+	if ((native && (msg->size > AUX_CMD_NATIVE_MAX)) ||
+		(msg->size > AUX_CMD_I2C_MAX)) {
+		pr_err("%s: invalid msg: size(%d), request(%x)\n",
+			__func__, msg->size, msg->request);
+		return -EINVAL;
+	}
+
+	mutex_lock(&aux->msg_mutex);
+
+	aux->msg_err = false;
+	reinit_completion(&aux->msg_comp);
+
+	ret = edp_msg_fifo_tx(aux, msg);
+	if (ret < 0)
+		goto unlock_exit;
+
+	DBG("wait_for_completion");
+	ret = wait_for_completion_timeout(&aux->msg_comp, 300);
+	if (ret <= 0) {
+		/*
+		 * Clear GO and reset AUX channel
+		 * to cancel the current transaction.
+		 */
+		edp_write(aux->base + REG_EDP_AUX_TRANS_CTRL, 0);
+		msm_edp_aux_ctrl(aux, 1);
+		pr_err("%s: aux timeout, %d\n", __func__, ret);
+		goto unlock_exit;
+	}
+	DBG("completion");
+
+	if (!aux->msg_err) {
+		if (read) {
+			ret = edp_msg_fifo_rx(aux, msg);
+			if (ret < 0)
+				goto unlock_exit;
+		}
+
+		msg->reply = native ?
+			DP_AUX_NATIVE_REPLY_ACK : DP_AUX_I2C_REPLY_ACK;
+	} else {
+		/* Reply defer to retry */
+		msg->reply = native ?
+			DP_AUX_NATIVE_REPLY_DEFER : DP_AUX_I2C_REPLY_DEFER;
+		/*
+		 * The sleep time in caller is not long enough to make sure
+		 * our H/W completes transactions. Add more defer time here.
+		 */
+		msleep(100);
+	}
+
+	/* Return requested size for success or retry */
+	ret = msg->size;
+
+unlock_exit:
+	mutex_unlock(&aux->msg_mutex);
+	return ret;
+}
+
+void *msm_edp_aux_init(struct device *dev, void __iomem *regbase,
+	struct drm_dp_aux **drm_aux)
+{
+	struct edp_aux *aux = NULL;
+	int ret;
+
+	DBG("");
+	aux = devm_kzalloc(dev, sizeof(*aux), GFP_KERNEL);
+	if (!aux)
+		return NULL;
+
+	aux->base = regbase;
+	mutex_init(&aux->msg_mutex);
+	init_completion(&aux->msg_comp);
+
+	aux->drm_aux.name = "msm_edp_aux";
+	aux->drm_aux.dev = dev;
+	aux->drm_aux.transfer = edp_aux_transfer;
+	ret = drm_dp_aux_register(&aux->drm_aux);
+	if (ret) {
+		pr_err("%s: failed to register drm aux: %d\n", __func__, ret);
+		mutex_destroy(&aux->msg_mutex);
+	}
+
+	if (drm_aux && aux)
+		*drm_aux = &aux->drm_aux;
+
+	return aux;
+}
+
+void msm_edp_aux_destroy(struct device *dev, struct edp_aux *aux)
+{
+	if (aux) {
+		drm_dp_aux_unregister(&aux->drm_aux);
+		mutex_destroy(&aux->msg_mutex);
+	}
+}
+
+irqreturn_t msm_edp_aux_irq(struct edp_aux *aux, u32 isr)
+{
+	if (isr & EDP_INTR_TRANS_STATUS) {
+		DBG("isr=%x", isr);
+		edp_write(aux->base + REG_EDP_AUX_TRANS_CTRL, 0);
+
+		if (isr & EDP_INTR_AUX_I2C_ERR)
+			aux->msg_err = true;
+		else
+			aux->msg_err = false;
+
+		complete(&aux->msg_comp);
+	}
+
+	return IRQ_HANDLED;
+}
+
+void msm_edp_aux_ctrl(struct edp_aux *aux, int enable)
+{
+	u32 data;
+
+	DBG("enable=%d", enable);
+	data = edp_read(aux->base + REG_EDP_AUX_CTRL);
+
+	if (enable) {
+		data |= EDP_AUX_CTRL_RESET;
+		edp_write(aux->base + REG_EDP_AUX_CTRL, data);
+		/* Make sure full reset */
+		wmb();
+		usleep_range(500, 1000);
+
+		data &= ~EDP_AUX_CTRL_RESET;
+		data |= EDP_AUX_CTRL_ENABLE;
+		edp_write(aux->base + REG_EDP_AUX_CTRL, data);
+	} else {
+		data &= ~EDP_AUX_CTRL_ENABLE;
+		edp_write(aux->base + REG_EDP_AUX_CTRL, data);
+	}
+}
+

drivers/gpu/drm/msm/edp/edp_bridge.c

···
+/*
+ * Copyright (c) 2014-2015, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include "edp.h"
+
+struct edp_bridge {
+	struct drm_bridge base;
+	struct msm_edp *edp;
+};
+#define to_edp_bridge(x) container_of(x, struct edp_bridge, base)
+
+void edp_bridge_destroy(struct drm_bridge *bridge)
+{
+}
+
+static void edp_bridge_pre_enable(struct drm_bridge *bridge)
+{
+	struct edp_bridge *edp_bridge = to_edp_bridge(bridge);
+	struct msm_edp *edp = edp_bridge->edp;
+
+	DBG("");
+	msm_edp_ctrl_power(edp->ctrl, true);
+}
+
+static void edp_bridge_enable(struct drm_bridge *bridge)
+{
+	DBG("");
+}
+
+static void edp_bridge_disable(struct drm_bridge *bridge)
+{
+	DBG("");
+}
+
+static void edp_bridge_post_disable(struct drm_bridge *bridge)
+{
+	struct edp_bridge *edp_bridge = to_edp_bridge(bridge);
+	struct msm_edp *edp = edp_bridge->edp;
+
+	DBG("");
+	msm_edp_ctrl_power(edp->ctrl, false);
+}
+
+static void edp_bridge_mode_set(struct drm_bridge *bridge,
+		struct drm_display_mode *mode,
+		struct drm_display_mode *adjusted_mode)
+{
+	struct drm_device *dev = bridge->dev;
+	struct drm_connector *connector;
+	struct edp_bridge *edp_bridge = to_edp_bridge(bridge);
+	struct msm_edp *edp = edp_bridge->edp;
+
+	DBG("set mode: %d:\"%s\" %d %d %d %d %d %d %d %d %d %d 0x%x 0x%x",
+			mode->base.id, mode->name,
+			mode->vrefresh, mode->clock,
+			mode->hdisplay, mode->hsync_start,
+			mode->hsync_end, mode->htotal,
+			mode->vdisplay, mode->vsync_start,
+			mode->vsync_end, mode->vtotal,
+			mode->type, mode->flags);
+
+	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
+		if ((connector->encoder != NULL) &&
+			(connector->encoder->bridge == bridge)) {
+			msm_edp_ctrl_timing_cfg(edp->ctrl,
+				adjusted_mode, &connector->display_info);
+			break;
+		}
+	}
+}
+
+static const struct drm_bridge_funcs edp_bridge_funcs = {
+	.pre_enable = edp_bridge_pre_enable,
+	.enable = edp_bridge_enable,
+	.disable = edp_bridge_disable,
+	.post_disable = edp_bridge_post_disable,
+	.mode_set = edp_bridge_mode_set,
+};
+
+/* initialize bridge */
+struct drm_bridge *msm_edp_bridge_init(struct msm_edp *edp)
+{
+	struct drm_bridge *bridge = NULL;
+	struct edp_bridge *edp_bridge;
+	int ret;
+
+	edp_bridge = devm_kzalloc(edp->dev->dev,
+			sizeof(*edp_bridge), GFP_KERNEL);
+	if (!edp_bridge) {
+		ret = -ENOMEM;
+		goto fail;
+	}
+
+	edp_bridge->edp = edp;
+
+	bridge = &edp_bridge->base;
+	bridge->funcs = &edp_bridge_funcs;
+
+	ret = drm_bridge_attach(edp->dev, bridge);
+	if (ret)
+		goto fail;
+
+	return bridge;
+
+fail:
+	if (bridge)
+		edp_bridge_destroy(bridge);
+
+	return ERR_PTR(ret);
+}

drivers/gpu/drm/msm/edp/edp_connector.c

···
+/*
+ * Copyright (c) 2014-2015, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include "drm/drm_edid.h"
+#include "msm_kms.h"
+#include "edp.h"
+
+struct edp_connector {
+	struct drm_connector base;
+	struct msm_edp *edp;
+};
+#define to_edp_connector(x) container_of(x, struct edp_connector, base)
+
+static enum drm_connector_status edp_connector_detect(
+		struct drm_connector *connector, bool force)
+{
+	struct edp_connector *edp_connector = to_edp_connector(connector);
+	struct msm_edp *edp = edp_connector->edp;
+
+	DBG("");
+	return msm_edp_ctrl_panel_connected(edp->ctrl) ?
+		connector_status_connected : connector_status_disconnected;
+}
+
+static void edp_connector_destroy(struct drm_connector *connector)
+{
+	struct edp_connector *edp_connector = to_edp_connector(connector);
+
+	DBG("");
+	drm_connector_unregister(connector);
+	drm_connector_cleanup(connector);
+
+	kfree(edp_connector);
+}
+
+static int edp_connector_get_modes(struct drm_connector *connector)
+{
+	struct edp_connector *edp_connector = to_edp_connector(connector);
+	struct msm_edp *edp = edp_connector->edp;
+
+	struct edid *drm_edid = NULL;
+	int ret = 0;
+
+	DBG("");
+	ret = msm_edp_ctrl_get_panel_info(edp->ctrl, connector, &drm_edid);
+	if (ret)
+		return ret;
+
+	drm_mode_connector_update_edid_property(connector, drm_edid);
+	if (drm_edid)
+		ret = drm_add_edid_modes(connector, drm_edid);
+
+	return ret;
+}
+
+static int edp_connector_mode_valid(struct drm_connector *connector,
+				 struct drm_display_mode *mode)
+{
+	struct edp_connector *edp_connector = to_edp_connector(connector);
+	struct msm_edp *edp = edp_connector->edp;
+	struct msm_drm_private *priv = connector->dev->dev_private;
+	struct msm_kms *kms = priv->kms;
+	long actual, requested;
+
+	requested = 1000 * mode->clock;
+	actual = kms->funcs->round_pixclk(kms,
+			requested, edp_connector->edp->encoder);
+
+	DBG("requested=%ld, actual=%ld", requested, actual);
+	if (actual != requested)
+		return MODE_CLOCK_RANGE;
+
+	if (!msm_edp_ctrl_pixel_clock_valid(
+		edp->ctrl, mode->clock, NULL, NULL))
+		return MODE_CLOCK_RANGE;
+
+	/* Invalidate all modes if color format is not supported */
+	if (connector->display_info.bpc > 8)
+		return MODE_BAD;
+
+	return MODE_OK;
+}
+
+static struct drm_encoder *
+edp_connector_best_encoder(struct drm_connector *connector)
+{
+	struct edp_connector *edp_connector = to_edp_connector(connector);
+
+	DBG("");
+	return edp_connector->edp->encoder;
+}
+
+static const struct drm_connector_funcs edp_connector_funcs = {
+	.dpms = drm_atomic_helper_connector_dpms,
+	.detect = edp_connector_detect,
+	.fill_modes = drm_helper_probe_single_connector_modes,
+	.destroy = edp_connector_destroy,
+	.reset = drm_atomic_helper_connector_reset,
+	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+};
+
+static const struct drm_connector_helper_funcs edp_connector_helper_funcs = {
+	.get_modes = edp_connector_get_modes,
+	.mode_valid = edp_connector_mode_valid,
+	.best_encoder = edp_connector_best_encoder,
+};
+
+/* initialize connector */
+struct drm_connector *msm_edp_connector_init(struct msm_edp *edp)
+{
+	struct drm_connector *connector = NULL;
+	struct edp_connector *edp_connector;
+	int ret;
+
+	edp_connector = kzalloc(sizeof(*edp_connector), GFP_KERNEL);
+	if (!edp_connector) {
+		ret = -ENOMEM;
+		goto fail;
+	}
+
+	edp_connector->edp = edp;
+
+	connector = &edp_connector->base;
+
+	ret = drm_connector_init(edp->dev, connector, &edp_connector_funcs,
+			DRM_MODE_CONNECTOR_eDP);
+	if (ret)
+		goto fail;
+
+	drm_connector_helper_add(connector, &edp_connector_helper_funcs);
+
+	/* We don't support HPD, so only poll status until connected. */
+	connector->polled = DRM_CONNECTOR_POLL_CONNECT;
+
+	/* Display driver doesn't support interlace now. */
+	connector->interlace_allowed = false;
+	connector->doublescan_allowed = false;
+
+	ret = drm_connector_register(connector);
+	if (ret)
+		goto fail;
+
+	return connector;
+
+fail:
+	if (connector)
+		edp_connector_destroy(connector);
+
+	return ERR_PTR(ret);
+}

drivers/gpu/drm/msm/edp/edp_ctrl.c

···
+/*
+ * Copyright (c) 2014-2015, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/gpio/consumer.h>
+#include <linux/regulator/consumer.h>
+
+#include "drm_crtc.h"
+#include "drm_dp_helper.h"
+#include "drm_edid.h"
+#include "edp.h"
+#include "edp.xml.h"
+
+#define VDDA_MIN_UV		1800000	/* uV units */
+#define VDDA_MAX_UV		1800000	/* uV units */
+#define VDDA_UA_ON_LOAD		100000	/* uA units */
+#define VDDA_UA_OFF_LOAD	100	/* uA units */
+
+#define DPCD_LINK_VOLTAGE_MAX		4
+#define DPCD_LINK_PRE_EMPHASIS_MAX	4
+
+#define EDP_LINK_BW_MAX		DP_LINK_BW_2_7
+
+/* Link training return value */
+#define EDP_TRAIN_FAIL		-1
+#define EDP_TRAIN_SUCCESS	0
+#define EDP_TRAIN_RECONFIG	1
+
+#define EDP_CLK_MASK_AHB		BIT(0)
+#define EDP_CLK_MASK_AUX		BIT(1)
+#define EDP_CLK_MASK_LINK		BIT(2)
+#define EDP_CLK_MASK_PIXEL		BIT(3)
+#define EDP_CLK_MASK_MDP_CORE		BIT(4)
+#define EDP_CLK_MASK_LINK_CHAN	(EDP_CLK_MASK_LINK | EDP_CLK_MASK_PIXEL)
+#define EDP_CLK_MASK_AUX_CHAN	\
+	(EDP_CLK_MASK_AHB | EDP_CLK_MASK_AUX | EDP_CLK_MASK_MDP_CORE)
+#define EDP_CLK_MASK_ALL	(EDP_CLK_MASK_AUX_CHAN | EDP_CLK_MASK_LINK_CHAN)
+
+#define EDP_BACKLIGHT_MAX	255
+
+#define EDP_INTR_STATUS1	\
+	(EDP_INTERRUPT_REG_1_HPD | EDP_INTERRUPT_REG_1_AUX_I2C_DONE | \
+	EDP_INTERRUPT_REG_1_WRONG_ADDR | EDP_INTERRUPT_REG_1_TIMEOUT | \
+	EDP_INTERRUPT_REG_1_NACK_DEFER | EDP_INTERRUPT_REG_1_WRONG_DATA_CNT | \
+	EDP_INTERRUPT_REG_1_I2C_NACK | EDP_INTERRUPT_REG_1_I2C_DEFER | \
+	EDP_INTERRUPT_REG_1_PLL_UNLOCK | EDP_INTERRUPT_REG_1_AUX_ERROR)
+#define EDP_INTR_MASK1	(EDP_INTR_STATUS1 << 2)
+#define EDP_INTR_STATUS2	\
+	(EDP_INTERRUPT_REG_2_READY_FOR_VIDEO | \
+	EDP_INTERRUPT_REG_2_IDLE_PATTERNs_SENT | \
+	EDP_INTERRUPT_REG_2_FRAME_END | EDP_INTERRUPT_REG_2_CRC_UPDATED)
+#define EDP_INTR_MASK2	(EDP_INTR_STATUS2 << 2)
+
+struct edp_ctrl {
+	struct platform_device *pdev;
+
+	void __iomem *base;
+
+	/* regulators */
+	struct regulator *vdda_vreg;
+	struct regulator *lvl_vreg;
+
+	/* clocks */
+	struct clk *aux_clk;
+	struct clk *pixel_clk;
+	struct clk *ahb_clk;
+	struct clk *link_clk;
+	struct clk *mdp_core_clk;
+
+	/* gpios */
+	struct gpio_desc *panel_en_gpio;
+	struct gpio_desc *panel_hpd_gpio;
+
+	/* completion and mutex */
+	struct completion idle_comp;
+	struct mutex dev_mutex; /* To protect device power status */
+
+	/* work queue */
+	struct work_struct on_work;
+	struct work_struct off_work;
+	struct workqueue_struct *workqueue;
+
+	/* Interrupt register lock */
+	spinlock_t irq_lock;
+
+	bool edp_connected;
+	bool power_on;
+
+	/* edid raw data */
+	struct edid *edid;
+
+	struct drm_dp_link dp_link;
+	struct drm_dp_aux *drm_aux;
+
+	/* dpcd raw data */
+	u8 dpcd[DP_RECEIVER_CAP_SIZE];
+
+	/* Link status */
+	u8 link_rate;
+	u8 lane_cnt;
+	u8 v_level;
+	u8 p_level;
+
+	/* Timing status */
+	u8 interlaced;
+	u32 pixel_rate; /* in kHz */
+	u32 color_depth;
+
+	struct edp_aux *aux;
+	struct edp_phy *phy;
+};
+
+struct edp_pixel_clk_div {
+	u32 rate; /* in kHz */
+	u32 m;
+	u32 n;
+};
+
+#define EDP_PIXEL_CLK_NUM 8
+static const struct edp_pixel_clk_div clk_divs[2][EDP_PIXEL_CLK_NUM] = {
+	{ /* Link clock = 162MHz, source clock = 810MHz */
+		{119000, 31,  211}, /* WSXGA+ 1680x1050@60Hz CVT */
+		{130250, 32,  199}, /* UXGA 1600x1200@60Hz CVT */
+		{148500, 11,  60},  /* FHD 1920x1080@60Hz */
+		{154000, 50,  263}, /* WUXGA 1920x1200@60Hz CVT */
+		{209250, 31,  120}, /* QXGA 2048x1536@60Hz CVT */
+		{268500, 119, 359}, /* WQXGA 2560x1600@60Hz CVT */
+		{138530, 33,  193}, /* AUO B116HAN03.0 Panel */
+		{141400, 48,  275}, /* AUO B133HTN01.2 Panel */
+	},
+	{ /* Link clock = 270MHz, source clock = 675MHz */
+		{119000, 52,  295}, /* WSXGA+ 1680x1050@60Hz CVT */
+		{130250, 11,  57},  /* UXGA 1600x1200@60Hz CVT */
+		{148500, 11,  50},  /* FHD 1920x1080@60Hz */
+		{154000, 47,  206}, /* WUXGA 1920x1200@60Hz CVT */
+		{209250, 31,  100}, /* QXGA 2048x1536@60Hz CVT */
+		{268500, 107, 269}, /* WQXGA 2560x1600@60Hz CVT */
+		{138530, 63,  307}, /* AUO B116HAN03.0 Panel */
+		{141400, 53,  253}, /* AUO B133HTN01.2 Panel */
+	},
+};
+
+static int edp_clk_init(struct edp_ctrl *ctrl)
+{
+	struct device *dev = &ctrl->pdev->dev;
+	int ret;
+
+	ctrl->aux_clk = devm_clk_get(dev, "core_clk");
+	if (IS_ERR(ctrl->aux_clk)) {
+		ret = PTR_ERR(ctrl->aux_clk);
+		pr_err("%s: Can't find aux_clk, %d\n", __func__, ret);
+		ctrl->aux_clk = NULL;
+		return ret;
+	}
+
+	ctrl->pixel_clk = devm_clk_get(dev, "pixel_clk");
+	if (IS_ERR(ctrl->pixel_clk)) {
+		ret = PTR_ERR(ctrl->pixel_clk);
+		pr_err("%s: Can't find pixel_clk, %d\n", __func__, ret);
+		ctrl->pixel_clk = NULL;
+		return ret;
+	}
+
+	ctrl->ahb_clk = devm_clk_get(dev, "iface_clk");
+	if (IS_ERR(ctrl->ahb_clk)) {
+		ret = PTR_ERR(ctrl->ahb_clk);
+		pr_err("%s: Can't find ahb_clk, %d\n", __func__, ret);
+		ctrl->ahb_clk = NULL;
+		return ret;
+	}
+
+	ctrl->link_clk = devm_clk_get(dev, "link_clk");
+	if (IS_ERR(ctrl->link_clk)) {
+		ret = PTR_ERR(ctrl->link_clk);
+		pr_err("%s: Can't find link_clk, %d\n", __func__, ret);
+		ctrl->link_clk = NULL;
+		return ret;
+	}
+
+	/* need mdp core clock to receive irq */
+	ctrl->mdp_core_clk = devm_clk_get(dev, "mdp_core_clk");
+	if (IS_ERR(ctrl->mdp_core_clk)) {
+		ret = PTR_ERR(ctrl->mdp_core_clk);
+		pr_err("%s: Can't find mdp_core_clk, %d\n", __func__, ret);
+		ctrl->mdp_core_clk = NULL;
+		return ret;
+	}
+
+	return 0;
+}
+
+static int edp_clk_enable(struct edp_ctrl *ctrl, u32 clk_mask)
+{
+	int ret;
+
+	DBG("mask=%x", clk_mask);
+	/* ahb_clk should be enabled first */
+	if (clk_mask & EDP_CLK_MASK_AHB) {
+		ret = clk_prepare_enable(ctrl->ahb_clk);
+		if (ret) {
+			pr_err("%s: Failed to enable ahb clk\n", __func__);
+			goto f0;
+		}
+	}
+	if (clk_mask & EDP_CLK_MASK_AUX) {
+		ret = clk_set_rate(ctrl->aux_clk, 19200000);
+		if (ret) {
+			pr_err("%s: Failed to set rate aux clk\n", __func__);
+			goto f1;
+		}
+		ret = clk_prepare_enable(ctrl->aux_clk);
+		if (ret) {
+			pr_err("%s: Failed to enable aux clk\n", __func__);
+			goto f1;
+		}
+	}
+	/* Need to set rate and enable link_clk prior to pixel_clk */
+	if (clk_mask & EDP_CLK_MASK_LINK) {
+		DBG("edp->link_clk, set_rate %ld",
+				(unsigned long)ctrl->link_rate * 27000000);
+		ret = clk_set_rate(ctrl->link_clk,
+				(unsigned long)ctrl->link_rate * 27000000);
+		if (ret) {
+			pr_err("%s: Failed to set rate to link clk\n",
+				__func__);
+			goto f2;
+		}
+
+		ret = clk_prepare_enable(ctrl->link_clk);
+		if (ret) {
+			pr_err("%s: Failed to enable link clk\n", __func__);
+			goto f2;
+		}
+	}
+	if (clk_mask & EDP_CLK_MASK_PIXEL) {
+		DBG("edp->pixel_clk, set_rate %ld",
+				(unsigned long)ctrl->pixel_rate * 1000);
+		ret = clk_set_rate(ctrl->pixel_clk,
+				(unsigned long)ctrl->pixel_rate * 1000);
+		if (ret) {
+			pr_err("%s: Failed to set rate to pixel clk\n",
+				__func__);
+			goto f3;
+		}
+
+		ret = clk_prepare_enable(ctrl->pixel_clk);
+		if (ret) {
+			pr_err("%s: Failed to enable pixel clk\n", __func__);
+			goto f3;
+		}
+	}
+	if (clk_mask & EDP_CLK_MASK_MDP_CORE) {
+		ret = clk_prepare_enable(ctrl->mdp_core_clk);
+		if (ret) {
+			pr_err("%s: Failed to enable mdp core clk\n", __func__);
+			goto f4;
+		}
+	}
+
+	return 0;
+
+f4:
+	if (clk_mask & EDP_CLK_MASK_PIXEL)
+		clk_disable_unprepare(ctrl->pixel_clk);
+f3:
+	if (clk_mask & EDP_CLK_MASK_LINK)
+		clk_disable_unprepare(ctrl->link_clk);
+f2:
+	if (clk_mask & EDP_CLK_MASK_AUX)
+		clk_disable_unprepare(ctrl->aux_clk);
+f1:
+	if (clk_mask & EDP_CLK_MASK_AHB)
+		clk_disable_unprepare(ctrl->ahb_clk);
+f0:
+	return ret;
+}
+
+static void edp_clk_disable(struct edp_ctrl *ctrl, u32 clk_mask)
+{
+	if (clk_mask & EDP_CLK_MASK_MDP_CORE)
+		clk_disable_unprepare(ctrl->mdp_core_clk);
+	if (clk_mask & EDP_CLK_MASK_PIXEL)
+		clk_disable_unprepare(ctrl->pixel_clk);
+	if (clk_mask & EDP_CLK_MASK_LINK)
+		clk_disable_unprepare(ctrl->link_clk);
+	if (clk_mask & EDP_CLK_MASK_AUX)
+		clk_disable_unprepare(ctrl->aux_clk);
+	if (clk_mask & EDP_CLK_MASK_AHB)
+		clk_disable_unprepare(ctrl->ahb_clk);
+}
+
+static int edp_regulator_init(struct edp_ctrl *ctrl)
+{
+	struct device *dev = &ctrl->pdev->dev;
+
+	DBG("");
+	ctrl->vdda_vreg = devm_regulator_get(dev, "vdda");
+	if (IS_ERR(ctrl->vdda_vreg)) {
+		pr_err("%s: Could not get vdda reg, ret = %ld\n", __func__,
+				PTR_ERR(ctrl->vdda_vreg));
+		ctrl->vdda_vreg = NULL;
+		return PTR_ERR(ctrl->vdda_vreg);
+	}
+	ctrl->lvl_vreg = devm_regulator_get(dev, "lvl-vdd");
+	if (IS_ERR(ctrl->lvl_vreg)) {
+		pr_err("Could not get lvl-vdd reg, %ld",
+				PTR_ERR(ctrl->lvl_vreg));
+		ctrl->lvl_vreg = NULL;
+		return PTR_ERR(ctrl->lvl_vreg);
+	}
+
+	return 0;
+}
+
+static int edp_regulator_enable(struct edp_ctrl *ctrl)
+{
+	int ret;
+
+	ret = regulator_set_voltage(ctrl->vdda_vreg, VDDA_MIN_UV, VDDA_MAX_UV);
+	if (ret) {
+		pr_err("%s:vdda_vreg set_voltage failed, %d\n", __func__, ret);
+		goto vdda_set_fail;
+	}
+
+	ret = regulator_set_optimum_mode(ctrl->vdda_vreg, VDDA_UA_ON_LOAD);
+	if (ret < 0) {
+		pr_err("%s: vdda_vreg set regulator mode failed.\n", __func__);
+		goto vdda_set_fail;
+	}
+
+	ret = regulator_enable(ctrl->vdda_vreg);
+	if (ret) {
+		pr_err("%s: Failed to enable vdda_vreg regulator.\n", __func__);
+		goto vdda_enable_fail;
+	}
+
+	ret = regulator_enable(ctrl->lvl_vreg);
+	if (ret) {
+		pr_err("Failed to enable lvl-vdd reg regulator, %d", ret);
+		goto lvl_enable_fail;
+	}
+
+	DBG("exit");
+	return 0;
+
+lvl_enable_fail:
+	regulator_disable(ctrl->vdda_vreg);
+vdda_enable_fail:
+	regulator_set_optimum_mode(ctrl->vdda_vreg, VDDA_UA_OFF_LOAD);
+vdda_set_fail:
+	return ret;
+}
+
+static void edp_regulator_disable(struct edp_ctrl *ctrl)
+{
+	regulator_disable(ctrl->lvl_vreg);
+	regulator_disable(ctrl->vdda_vreg);
+	regulator_set_optimum_mode(ctrl->vdda_vreg, VDDA_UA_OFF_LOAD);
+}
+
+static int edp_gpio_config(struct edp_ctrl *ctrl)
+{
+	struct device *dev = &ctrl->pdev->dev;
+	int ret;
+
+	ctrl->panel_hpd_gpio = devm_gpiod_get(dev, "panel-hpd");
+	if (IS_ERR(ctrl->panel_hpd_gpio)) {
+		ret = PTR_ERR(ctrl->panel_hpd_gpio);
+		ctrl->panel_hpd_gpio = NULL;
+		pr_err("%s: cannot get panel-hpd-gpios, %d\n", __func__, ret);
+		return ret;
+	}
+
+	ret = gpiod_direction_input(ctrl->panel_hpd_gpio);
+	if (ret) {
+		pr_err("%s: Set direction for hpd failed, %d\n", __func__, ret);
+		return ret;
+	}
+
+	ctrl->panel_en_gpio = devm_gpiod_get(dev, "panel-en");
+	if (IS_ERR(ctrl->panel_en_gpio)) {
+		ret = PTR_ERR(ctrl->panel_en_gpio);
+		ctrl->panel_en_gpio = NULL;
+		pr_err("%s: cannot get panel-en-gpios, %d\n", __func__, ret);
+		return ret;
+	}
+
+	ret = gpiod_direction_output(ctrl->panel_en_gpio, 0);
+	if (ret) {
+		pr_err("%s: Set direction for panel_en failed, %d\n",
+				__func__, ret);
+		return ret;
+	}
+
+	DBG("gpio on");
+
+	return 0;
+}
+
+static void edp_ctrl_irq_enable(struct edp_ctrl *ctrl, int enable)
+{
+	unsigned long flags;
+
+	DBG("%d", enable);
+	spin_lock_irqsave(&ctrl->irq_lock, flags);
+	if (enable) {
+		edp_write(ctrl->base + REG_EDP_INTERRUPT_REG_1, EDP_INTR_MASK1);
+		edp_write(ctrl->base + REG_EDP_INTERRUPT_REG_2, EDP_INTR_MASK2);
+	} else {
+		edp_write(ctrl->base + REG_EDP_INTERRUPT_REG_1, 0x0);
+		edp_write(ctrl->base + REG_EDP_INTERRUPT_REG_2, 0x0);
+	}
+	spin_unlock_irqrestore(&ctrl->irq_lock, flags);
+	DBG("exit");
+}
+
+static void edp_fill_link_cfg(struct edp_ctrl *ctrl)
+{
+	u32 prate;
+	u32 lrate;
+	u32 bpp;
+	u8 max_lane = ctrl->dp_link.num_lanes;
+	u8 lane;
+
+	prate = ctrl->pixel_rate;
+	bpp = ctrl->color_depth * 3;
+
+	/*
+	 * By default, use the maximum link rate and minimum lane count,
+	 * so that we can do rate down shift during link training.
+	 */
+	ctrl->link_rate = drm_dp_link_rate_to_bw_code(ctrl->dp_link.rate);
+
+	prate *= bpp;
+	prate /= 8; /* in kByte */
+
+	lrate = 270000; /* in kHz */
+	lrate *= ctrl->link_rate;
+	lrate /= 10; /* in kByte, 10 bits --> 8 bits */
+
+	for (lane = 1; lane <= max_lane; lane <<= 1) {
+		if (lrate >= prate)
+			break;
+		lrate <<= 1;
+	}
+
+	ctrl->lane_cnt = lane;
+	DBG("rate=%d lane=%d", ctrl->link_rate, ctrl->lane_cnt);
+}
+
+static int edp_sink_power_state(struct edp_ctrl *ctrl, u8 state)
+{
+	u8 s = state;
+
+	DBG("%d", s);
+
+	if (ctrl->dp_link.revision < 0x11)
+		return 0;
+
+	if (drm_dp_dpcd_write(ctrl->drm_aux, DP_SET_POWER, &s, 1) < 1) {
+		pr_err("%s: Set power state to panel failed\n", __func__);
+		return -ENOLINK;
+	}
+
+	return 0;
+}
+
+static void edp_config_ctrl(struct edp_ctrl *ctrl)
+{
+	u32 data;
+	enum edp_color_depth depth;
+
+	data = EDP_CONFIGURATION_CTRL_LANES(ctrl->lane_cnt - 1);
+
+	if (ctrl->dp_link.capabilities & DP_LINK_CAP_ENHANCED_FRAMING)
+		data |= EDP_CONFIGURATION_CTRL_ENHANCED_FRAMING;
+
+	depth = EDP_6BIT;
+	if (ctrl->color_depth == 8)
+		depth = EDP_8BIT;
+
+	data |= EDP_CONFIGURATION_CTRL_COLOR(depth);
+
+	if (!ctrl->interlaced)	/* progressive */
+		data |= EDP_CONFIGURATION_CTRL_PROGRESSIVE;
+
+	data |= (EDP_CONFIGURATION_CTRL_SYNC_CLK |
+		EDP_CONFIGURATION_CTRL_STATIC_MVID);
+
+	edp_write(ctrl->base + REG_EDP_CONFIGURATION_CTRL, data);
+}
+
+static void edp_state_ctrl(struct edp_ctrl *ctrl, u32 state)
+{
+	edp_write(ctrl->base + REG_EDP_STATE_CTRL, state);
+	/* Make sure H/W status is set */
+	wmb();
+}
+
+static int edp_lane_set_write(struct edp_ctrl *ctrl,
+	u8 voltage_level, u8 pre_emphasis_level)
+{
+	int i;
+	u8 buf[4];
+
+	if (voltage_level >= DPCD_LINK_VOLTAGE_MAX)
+		voltage_level |= 0x04;
+
+	if (pre_emphasis_level >= DPCD_LINK_PRE_EMPHASIS_MAX)
+		pre_emphasis_level |= 0x04;
+
+	pre_emphasis_level <<= 3;
+
+	for (i = 0; i < 4; i++)
+		buf[i] = voltage_level | pre_emphasis_level;
+
+	DBG("%s: p|v=0x%x", __func__, voltage_level | pre_emphasis_level);
+	if (drm_dp_dpcd_write(ctrl->drm_aux, 0x103, buf, 4) < 4) {
+		pr_err("%s: Set sw/pe to panel failed\n", __func__);
+		return -ENOLINK;
+	}
+
+	return 0;
+}
+
+static int edp_train_pattern_set_write(struct edp_ctrl *ctrl, u8 pattern)
+{
+	u8 p = pattern;
+
+	DBG("pattern=%x", p);
+	if (drm_dp_dpcd_write(ctrl->drm_aux,
+				DP_TRAINING_PATTERN_SET, &p, 1) < 1) {
+		pr_err("%s: Set training pattern to panel failed\n", __func__);
+		return -ENOLINK;
+	}
+
+	return 0;
+}
+
+static void edp_sink_train_set_adjust(struct edp_ctrl *ctrl,
+	const u8 *link_status)
+{
+	int i;
+	u8 max = 0;
+	u8 data;
+
+	/* use the max level across lanes */
+	for (i = 0; i < ctrl->lane_cnt; i++) {
+		data = drm_dp_get_adjust_request_voltage(link_status, i);
+		DBG("lane=%d req_voltage_swing=0x%x", i, data);
+		if (max < data)
+			max = data;
+	}
+
+	ctrl->v_level = max >> DP_TRAIN_VOLTAGE_SWING_SHIFT;
+
+	/* use the max level across lanes */
+	max = 0;
+	for (i = 0; i < ctrl->lane_cnt; i++) {
+		data = drm_dp_get_adjust_request_pre_emphasis(link_status, i);
+		DBG("lane=%d req_pre_emphasis=0x%x", i, data);
+		if (max < data)
+			max = data;
+	}
+
+	ctrl->p_level = max >> DP_TRAIN_PRE_EMPHASIS_SHIFT;
+	DBG("v_level=%d, p_level=%d", ctrl->v_level, ctrl->p_level);
+}
+
+static void edp_host_train_set(struct edp_ctrl *ctrl, u32 train)
+{
+	int cnt = 10;
+	u32 data;
+	u32 shift = train - 1;
+
+	DBG("train=%d", train);
+
+	edp_state_ctrl(ctrl, EDP_STATE_CTRL_TRAIN_PATTERN_1 << shift);
+	while (--cnt) {
+		data = edp_read(ctrl->base + REG_EDP_MAINLINK_READY);
+		if (data & (EDP_MAINLINK_READY_TRAIN_PATTERN_1_READY << shift))
+			break;
+	}
+
+	if (cnt == 0)
+		pr_err("%s: set link_train=%d failed\n", __func__, train);
+}
+
+static const u8 vm_pre_emphasis[4][4] = {
+	{0x03, 0x06, 0x09, 0x0C},	/* pe0, 0 db */
+	{0x03, 0x06, 0x09, 0xFF},	/* pe1, 3.5 db */
+	{0x03, 0x06, 0xFF, 0xFF},	/* pe2, 6.0 db */
+	{0x03, 0xFF, 0xFF, 0xFF}	/* pe3, 9.5 db */
+};
+
+/* voltage swing, 0.2v and 1.0v are not support */
+static const u8 vm_voltage_swing[4][4] = {
+	{0x14, 0x18, 0x1A, 0x1E}, /* sw0, 0.4v  */
+	{0x18, 0x1A, 0x1E, 0xFF}, /* sw1, 0.6 v */
+	{0x1A, 0x1E, 0xFF, 0xFF}, /* sw1, 0.8 v */
+	{0x1E, 0xFF, 0xFF, 0xFF}  /* sw1, 1.2 v, optional */
+};
+
+static int edp_voltage_pre_emphasise_set(struct edp_ctrl *ctrl)
+{
+	u32 value0;
+	u32 value1;
+
+	DBG("v=%d p=%d", ctrl->v_level, ctrl->p_level);
+
+	value0 = vm_pre_emphasis[(int)(ctrl->v_level)][(int)(ctrl->p_level)];
+	value1 = vm_voltage_swing[(int)(ctrl->v_level)][(int)(ctrl->p_level)];
+
+	/* Configure host and panel only if both values are allowed */
+	if (value0 != 0xFF && value1 != 0xFF) {
+		msm_edp_phy_vm_pe_cfg(ctrl->phy, value0, value1);
+		return edp_lane_set_write(ctrl, ctrl->v_level, ctrl->p_level);
+	}
+
+	return -EINVAL;
+}
+
+static int edp_start_link_train_1(struct edp_ctrl *ctrl)
+{
+	u8 link_status[DP_LINK_STATUS_SIZE];
+	u8 old_v_level;
+	int tries;
+	int ret;
+	int rlen;
+
+	DBG("");
+
+	edp_host_train_set(ctrl, DP_TRAINING_PATTERN_1);
+	ret = edp_voltage_pre_emphasise_set(ctrl);
+	if (ret)
+		return ret;
+	ret = edp_train_pattern_set_write(ctrl,
+			DP_TRAINING_PATTERN_1 | DP_RECOVERED_CLOCK_OUT_EN);
+	if (ret)
+		return ret;
+
+	tries = 0;
+	old_v_level = ctrl->v_level;
+	while (1) {
+		drm_dp_link_train_clock_recovery_delay(ctrl->dpcd);
+
+		rlen = drm_dp_dpcd_read_link_status(ctrl->drm_aux, link_status);
+		if (rlen < DP_LINK_STATUS_SIZE) {
+			pr_err("%s: read link status failed\n", __func__);
+			return -ENOLINK;
+		}
+		if (drm_dp_clock_recovery_ok(link_status, ctrl->lane_cnt)) {
+			ret = 0;
+			break;
+		}
+
+		if (ctrl->v_level == DPCD_LINK_VOLTAGE_MAX) {
+			ret = -1;
+			break;
+		}
+
+		if (old_v_level == ctrl->v_level) {
+			tries++;
+			if (tries >= 5) {
+				ret = -1;
+				break;
+			}
+		} else {
+			tries = 0;
+			old_v_level = ctrl->v_level;
+		}
+
+		edp_sink_train_set_adjust(ctrl, link_status);
+		ret = edp_voltage_pre_emphasise_set(ctrl);
+		if (ret)
+			return ret;
+	}
+
+	return ret;
+}
+
+static int edp_start_link_train_2(struct edp_ctrl *ctrl)
+{
+	u8 link_status[DP_LINK_STATUS_SIZE];
+	int tries = 0;
+	int ret;
+	int rlen;
+
+	DBG("");
+
+	edp_host_train_set(ctrl, DP_TRAINING_PATTERN_2);
+	ret = edp_voltage_pre_emphasise_set(ctrl);
+	if (ret)
+		return ret;
+
+	ret = edp_train_pattern_set_write(ctrl,
+			DP_TRAINING_PATTERN_2 | DP_RECOVERED_CLOCK_OUT_EN);
+	if (ret)
+		return ret;
+
+	while (1) {
+		drm_dp_link_train_channel_eq_delay(ctrl->dpcd);
+
+		rlen = drm_dp_dpcd_read_link_status(ctrl->drm_aux, link_status);
+		if (rlen < DP_LINK_STATUS_SIZE) {
+			pr_err("%s: read link status failed\n", __func__);
+			return -ENOLINK;
+		}
+		if (drm_dp_channel_eq_ok(link_status, ctrl->lane_cnt)) {
+			ret = 0;
+			break;
+		}
+
+		tries++;
+		if (tries > 10) {
+			ret = -1;
+			break;
+		}
+
+		edp_sink_train_set_adjust(ctrl, link_status);
+		ret = edp_voltage_pre_emphasise_set(ctrl);
+		if (ret)
+			return ret;
+	}
+
+	return ret;
+}
+
+static int edp_link_rate_down_shift(struct edp_ctrl *ctrl)
+{
+	u32 prate, lrate, bpp;
+	u8 rate, lane, max_lane;
+	int changed = 0;
+
+	rate = ctrl->link_rate;
+	lane = ctrl->lane_cnt;
+	max_lane = ctrl->dp_link.num_lanes;
+
+	bpp = ctrl->color_depth * 3;
+	prate = ctrl->pixel_rate;
+	prate *= bpp;
+	prate /= 8; /* in kByte */
+
+	if (rate > DP_LINK_BW_1_62 && rate <= EDP_LINK_BW_MAX) {
+		rate -= 4;	/* reduce rate */
+		changed++;
+	}
+
+	if (changed) {
+		if (lane >= 1 && lane < max_lane)
+			lane <<= 1;	/* increase lane */
+
+		lrate = 270000; /* in kHz */
+		lrate *= rate;
+		lrate /= 10; /* kByte, 10 bits --> 8 bits */
+		lrate *= lane;
+
+		DBG("new lrate=%u prate=%u(kHz) rate=%d lane=%d p=%u b=%d",
+			lrate, prate, rate, lane,
+			ctrl->pixel_rate,
+			bpp);
+
+		if (lrate > prate) {
+			ctrl->link_rate = rate;
+			ctrl->lane_cnt = lane;
+			DBG("new rate=%d %d", rate, lane);
+			return 0;
+		}
+	}
+
+	return -EINVAL;
+}
+
+static int edp_clear_training_pattern(struct edp_ctrl *ctrl)
+{
+	int ret;
+
+	ret = edp_train_pattern_set_write(ctrl, 0);
+
+	drm_dp_link_train_channel_eq_delay(ctrl->dpcd);
+
+	return ret;
+}
+
+static int edp_do_link_train(struct edp_ctrl *ctrl)
+{
+	int ret;
+	struct drm_dp_link dp_link;
+
+	DBG("");
+	/*
+	 * Set the current link rate and lane cnt to panel. They may have been
+	 * adjusted and the values are different from them in DPCD CAP
+	 */
+	dp_link.num_lanes = ctrl->lane_cnt;
+	dp_link.rate = drm_dp_bw_code_to_link_rate(ctrl->link_rate);
+	dp_link.capabilities = ctrl->dp_link.capabilities;
+	if (drm_dp_link_configure(ctrl->drm_aux, &dp_link) < 0)
+		return EDP_TRAIN_FAIL;
+
+	ctrl->v_level = 0; /* start from default level */
+	ctrl->p_level = 0;
+
+	edp_state_ctrl(ctrl, 0);
+	if (edp_clear_training_pattern(ctrl))
+		return EDP_TRAIN_FAIL;
+
+	ret = edp_start_link_train_1(ctrl);
+	if (ret < 0) {
+		if (edp_link_rate_down_shift(ctrl) == 0) {
+			DBG("link reconfig");
+			ret = EDP_TRAIN_RECONFIG;
+			goto clear;
+		} else {
+			pr_err("%s: Training 1 failed", __func__);
+			ret = EDP_TRAIN_FAIL;
+			goto clear;
+		}
+	}
+	DBG("Training 1 completed successfully");
+
+	edp_state_ctrl(ctrl, 0);
+	if (edp_clear_training_pattern(ctrl))
+		return EDP_TRAIN_FAIL;
+
+	ret = edp_start_link_train_2(ctrl);
+	if (ret < 0) {
+		if (edp_link_rate_down_shift(ctrl) == 0) {
+			DBG("link reconfig");
+			ret = EDP_TRAIN_RECONFIG;
+			goto clear;
+		} else {
+			pr_err("%s: Training 2 failed", __func__);
+			ret = EDP_TRAIN_FAIL;
+			goto clear;
+		}
+	}
+	DBG("Training 2 completed successfully");
+
+	edp_state_ctrl(ctrl, EDP_STATE_CTRL_SEND_VIDEO);
+clear:
+	edp_clear_training_pattern(ctrl);
+
+	return ret;
+}
+
+static void edp_clock_synchrous(struct edp_ctrl *ctrl, int sync)
+{
+	u32 data;
+	enum edp_color_depth depth;
+
+	data = edp_read(ctrl->base + REG_EDP_MISC1_MISC0);
+
+	if (sync)
+		data |= EDP_MISC1_MISC0_SYNC;
+	else
+		data &= ~EDP_MISC1_MISC0_SYNC;
+
+	/* only legacy rgb mode supported */
+	depth = EDP_6BIT; /* Default */
+	if (ctrl->color_depth == 8)
+		depth = EDP_8BIT;
+	else if (ctrl->color_depth == 10)
+		depth = EDP_10BIT;
+	else if (ctrl->color_depth == 12)
+		depth = EDP_12BIT;
+	else if (ctrl->color_depth == 16)
+		depth = EDP_16BIT;
+
+	data |= EDP_MISC1_MISC0_COLOR(depth);
+
+	edp_write(ctrl->base + REG_EDP_MISC1_MISC0, data);
+}
+
+static int edp_sw_mvid_nvid(struct edp_ctrl *ctrl, u32 m, u32 n)
+{
+	u32 n_multi, m_multi = 5;
+
+	if (ctrl->link_rate == DP_LINK_BW_1_62) {
+		n_multi = 1;
+	} else if (ctrl->link_rate == DP_LINK_BW_2_7) {
+		n_multi = 2;
+	} else {
+		pr_err("%s: Invalid link rate, %d\n", __func__,
+			ctrl->link_rate);
+		return -EINVAL;
+	}
+
+	edp_write(ctrl->base + REG_EDP_SOFTWARE_MVID, m * m_multi);
+	edp_write(ctrl->base + REG_EDP_SOFTWARE_NVID, n * n_multi);
+
+	return 0;
+}
+
+static void edp_mainlink_ctrl(struct edp_ctrl *ctrl, int enable)
+{
+	u32 data = 0;
+
+	edp_write(ctrl->base + REG_EDP_MAINLINK_CTRL, EDP_MAINLINK_CTRL_RESET);
+	/* Make sure fully reset */
+	wmb();
+	usleep_range(500, 1000);
+
+	if (enable)
+		data |= EDP_MAINLINK_CTRL_ENABLE;
+
+	edp_write(ctrl->base + REG_EDP_MAINLINK_CTRL, data);
+}
+
+static void edp_ctrl_phy_aux_enable(struct edp_ctrl *ctrl, int enable)
+{
+	if (enable) {
+		edp_regulator_enable(ctrl);
+		edp_clk_enable(ctrl, EDP_CLK_MASK_AUX_CHAN);
+		msm_edp_phy_ctrl(ctrl->phy, 1);
+		msm_edp_aux_ctrl(ctrl->aux, 1);
+		gpiod_set_value(ctrl->panel_en_gpio, 1);
+	} else {
+		gpiod_set_value(ctrl->panel_en_gpio, 0);
+		msm_edp_aux_ctrl(ctrl->aux, 0);
+		msm_edp_phy_ctrl(ctrl->phy, 0);
+		edp_clk_disable(ctrl, EDP_CLK_MASK_AUX_CHAN);
+		edp_regulator_disable(ctrl);
+	}
+}
+
+static void edp_ctrl_link_enable(struct edp_ctrl *ctrl, int enable)
+{
+	u32 m, n;
+
+	if (enable) {
+		/* Enable link channel clocks */
+		edp_clk_enable(ctrl, EDP_CLK_MASK_LINK_CHAN);
+
+		msm_edp_phy_lane_power_ctrl(ctrl->phy, true, ctrl->lane_cnt);
+
+		msm_edp_phy_vm_pe_init(ctrl->phy);
+
+		/* Make sure phy is programed */
+		wmb();
+		msm_edp_phy_ready(ctrl->phy);
+
+		edp_config_ctrl(ctrl);
+		msm_edp_ctrl_pixel_clock_valid(ctrl, ctrl->pixel_rate, &m, &n);
+		edp_sw_mvid_nvid(ctrl, m, n);
+		edp_mainlink_ctrl(ctrl, 1);
+	} else {
+		edp_mainlink_ctrl(ctrl, 0);
+
+		msm_edp_phy_lane_power_ctrl(ctrl->phy, false, 0);
+		edp_clk_disable(ctrl, EDP_CLK_MASK_LINK_CHAN);
+	}
+}
+
+static int edp_ctrl_training(struct edp_ctrl *ctrl)
+{
+	int ret;
+
+	/* Do link training only when power is on */
+	if (!ctrl->power_on)
+		return -EINVAL;
+
+train_start:
+	ret = edp_do_link_train(ctrl);
+	if (ret == EDP_TRAIN_RECONFIG) {
+		/* Re-configure main link */
+		edp_ctrl_irq_enable(ctrl, 0);
+		edp_ctrl_link_enable(ctrl, 0);
+		msm_edp_phy_ctrl(ctrl->phy, 0);
+
+		/* Make sure link is fully disabled */
+		wmb();
+		usleep_range(500, 1000);
+
+		msm_edp_phy_ctrl(ctrl->phy, 1);
+		edp_ctrl_link_enable(ctrl, 1);
+		edp_ctrl_irq_enable(ctrl, 1);
+		goto train_start;
+	}
+
+	return ret;
+}
+
+static void edp_ctrl_on_worker(struct work_struct *work)
+{
+	struct edp_ctrl *ctrl = container_of(
+				work, struct edp_ctrl, on_work);
+	int ret;
+
+	mutex_lock(&ctrl->dev_mutex);
+
+	if (ctrl->power_on) {
+		DBG("already on");
+		goto unlock_ret;
+	}
+
+	edp_ctrl_phy_aux_enable(ctrl, 1);
+	edp_ctrl_link_enable(ctrl, 1);
+
+	edp_ctrl_irq_enable(ctrl, 1);
+	ret = edp_sink_power_state(ctrl, DP_SET_POWER_D0);
+	if (ret)
+		goto fail;
+
+	ctrl->power_on = true;
+
+	/* Start link training */
+	ret = edp_ctrl_training(ctrl);
+	if (ret != EDP_TRAIN_SUCCESS)
+		goto fail;
+
+	DBG("DONE");
+	goto unlock_ret;
+
+fail:
+	edp_ctrl_irq_enable(ctrl, 0);
+	edp_ctrl_link_enable(ctrl, 0);
+	edp_ctrl_phy_aux_enable(ctrl, 0);
+	ctrl->power_on = false;
+unlock_ret:
+	mutex_unlock(&ctrl->dev_mutex);
+}
+
+static void edp_ctrl_off_worker(struct work_struct *work)
+{
+	struct edp_ctrl *ctrl = container_of(
+				work, struct edp_ctrl, off_work);
+	int ret;
+
+	mutex_lock(&ctrl->dev_mutex);
+
+	if (!ctrl->power_on) {
+		DBG("already off");
+		goto unlock_ret;
+	}
+
+	reinit_completion(&ctrl->idle_comp);
+	edp_state_ctrl(ctrl, EDP_STATE_CTRL_PUSH_IDLE);
+
+	ret = wait_for_completion_timeout(&ctrl->idle_comp,
+						msecs_to_jiffies(500));
+	if (ret <= 0)
+		DBG("%s: idle pattern timedout, %d\n",
+				__func__, ret);
+
+	edp_state_ctrl(ctrl, 0);
+
+	edp_sink_power_state(ctrl, DP_SET_POWER_D3);
+
+	edp_ctrl_irq_enable(ctrl, 0);
+
+	edp_ctrl_link_enable(ctrl, 0);
+
+	edp_ctrl_phy_aux_enable(ctrl, 0);
+
+	ctrl->power_on = false;
+
+unlock_ret:
+	mutex_unlock(&ctrl->dev_mutex);
+}
+
+irqreturn_t msm_edp_ctrl_irq(struct edp_ctrl *ctrl)
+{
+	u32 isr1, isr2, mask1, mask2;
+	u32 ack;
+
+	DBG("");
+	spin_lock(&ctrl->irq_lock);
+	isr1 = edp_read(ctrl->base + REG_EDP_INTERRUPT_REG_1);
+	isr2 = edp_read(ctrl->base + REG_EDP_INTERRUPT_REG_2);
+
+	mask1 = isr1 & EDP_INTR_MASK1;
+	mask2 = isr2 & EDP_INTR_MASK2;
+
+	isr1 &= ~mask1;	/* remove masks bit */
+	isr2 &= ~mask2;
+
+	DBG("isr=%x mask=%x isr2=%x mask2=%x",
+			isr1, mask1, isr2, mask2);
+
+	ack = isr1 & EDP_INTR_STATUS1;
+	ack <<= 1;	/* ack bits */
+	ack |= mask1;
+	edp_write(ctrl->base + REG_EDP_INTERRUPT_REG_1, ack);
+
+	ack = isr2 & EDP_INTR_STATUS2;
+	ack <<= 1;	/* ack bits */
+	ack |= mask2;
+	edp_write(ctrl->base + REG_EDP_INTERRUPT_REG_2, ack);
+	spin_unlock(&ctrl->irq_lock);
+
+	if (isr1 & EDP_INTERRUPT_REG_1_HPD)
+		DBG("edp_hpd");
+
+	if (isr2 & EDP_INTERRUPT_REG_2_READY_FOR_VIDEO)
+		DBG("edp_video_ready");
+
+	if (isr2 & EDP_INTERRUPT_REG_2_IDLE_PATTERNs_SENT) {
+		DBG("idle_patterns_sent");
+		complete(&ctrl->idle_comp);
+	}
+
+	msm_edp_aux_irq(ctrl->aux, isr1);
+
+	return IRQ_HANDLED;
+}
+
+void msm_edp_ctrl_power(struct edp_ctrl *ctrl, bool on)
+{
+	if (on)
+		queue_work(ctrl->workqueue, &ctrl->on_work);
+	else
+		queue_work(ctrl->workqueue, &ctrl->off_work);
+}
+
+int msm_edp_ctrl_init(struct msm_edp *edp)
+{
+	struct edp_ctrl *ctrl = NULL;
+	struct device *dev = &edp->pdev->dev;
+	int ret;
+
+	if (!edp) {
+		pr_err("%s: edp is NULL!\n", __func__);
+		return -EINVAL;
+	}
+
+	ctrl = devm_kzalloc(dev, sizeof(*ctrl), GFP_KERNEL);
+	if (!ctrl)
+		return -ENOMEM;
+
+	edp->ctrl = ctrl;
+	ctrl->pdev = edp->pdev;
+
+	ctrl->base = msm_ioremap(ctrl->pdev, "edp", "eDP");
+	if (IS_ERR(ctrl->base))
+		return PTR_ERR(ctrl->base);
+
+	/* Get regulator, clock, gpio, pwm */
+	ret = edp_regulator_init(ctrl);
+	if (ret) {
+		pr_err("%s:regulator init fail\n", __func__);
+		return ret;
+	}
+	ret = edp_clk_init(ctrl);
+	if (ret) {
+		pr_err("%s:clk init fail\n", __func__);
+		return ret;
+	}
+	ret = edp_gpio_config(ctrl);
+	if (ret) {
+		pr_err("%s:failed to configure GPIOs: %d", __func__, ret);
+		return ret;
+	}
+
+	/* Init aux and phy */
+	ctrl->aux = msm_edp_aux_init(dev, ctrl->base, &ctrl->drm_aux);
+	if (!ctrl->aux || !ctrl->drm_aux) {
+		pr_err("%s:failed to init aux\n", __func__);
+		return ret;
+	}
+
+	ctrl->phy = msm_edp_phy_init(dev, ctrl->base);
+	if (!ctrl->phy) {
+		pr_err("%s:failed to init phy\n", __func__);
+		goto err_destory_aux;
+	}
+
+	spin_lock_init(&ctrl->irq_lock);
+	mutex_init(&ctrl->dev_mutex);
+	init_completion(&ctrl->idle_comp);
+
+	/* setup workqueue */
+	ctrl->workqueue = alloc_ordered_workqueue("edp_drm_work", 0);
+	INIT_WORK(&ctrl->on_work, edp_ctrl_on_worker);
+	INIT_WORK(&ctrl->off_work, edp_ctrl_off_worker);
+
+	return 0;
+
+err_destory_aux:
+	msm_edp_aux_destroy(dev, ctrl->aux);
+	ctrl->aux = NULL;
+	return ret;
+}
+
+void msm_edp_ctrl_destroy(struct edp_ctrl *ctrl)
+{
+	if (!ctrl)
+		return;
+
+	if (ctrl->workqueue) {
+		flush_workqueue(ctrl->workqueue);
+		destroy_workqueue(ctrl->workqueue);
+		ctrl->workqueue = NULL;
+	}
+
+	if (ctrl->aux) {
+		msm_edp_aux_destroy(&ctrl->pdev->dev, ctrl->aux);
+		ctrl->aux = NULL;
+	}
+
+	kfree(ctrl->edid);
+	ctrl->edid = NULL;
+
+	mutex_destroy(&ctrl->dev_mutex);
+}
+
+bool msm_edp_ctrl_panel_connected(struct edp_ctrl *ctrl)
+{
+	mutex_lock(&ctrl->dev_mutex);
+	DBG("connect status = %d", ctrl->edp_connected);
+	if (ctrl->edp_connected) {
+		mutex_unlock(&ctrl->dev_mutex);
+		return true;
+	}
+
+	if (!ctrl->power_on) {
+		edp_ctrl_phy_aux_enable(ctrl, 1);
+		edp_ctrl_irq_enable(ctrl, 1);
+	}
+
+	if (drm_dp_dpcd_read(ctrl->drm_aux, DP_DPCD_REV, ctrl->dpcd,
+				DP_RECEIVER_CAP_SIZE) < DP_RECEIVER_CAP_SIZE) {
+		pr_err("%s: AUX channel is NOT ready\n", __func__);
+		memset(ctrl->dpcd, 0, DP_RECEIVER_CAP_SIZE);
+	} else {
+		ctrl->edp_connected = true;
+	}
+
+	if (!ctrl->power_on) {
+		edp_ctrl_irq_enable(ctrl, 0);
+		edp_ctrl_phy_aux_enable(ctrl, 0);
+	}
+
+	DBG("exit: connect status=%d", ctrl->edp_connected);
+
+	mutex_unlock(&ctrl->dev_mutex);
+
+	return ctrl->edp_connected;
+}
+
+int msm_edp_ctrl_get_panel_info(struct edp_ctrl *ctrl,
+		struct drm_connector *connector, struct edid **edid)
+{
+	int ret = 0;
+
+	mutex_lock(&ctrl->dev_mutex);
+
+	if (ctrl->edid) {
+		if (edid) {
+			DBG("Just return edid buffer");
+			*edid = ctrl->edid;
+		}
+		goto unlock_ret;
+	}
+
+	if (!ctrl->power_on) {
+		edp_ctrl_phy_aux_enable(ctrl, 1);
+		edp_ctrl_irq_enable(ctrl, 1);
+	}
+
+	ret = drm_dp_link_probe(ctrl->drm_aux, &ctrl->dp_link);
+	if (ret) {
+		pr_err("%s: read dpcd cap failed, %d\n", __func__, ret);
+		goto disable_ret;
+	}
+
+	/* Initialize link rate as panel max link rate */
+	ctrl->link_rate = drm_dp_link_rate_to_bw_code(ctrl->dp_link.rate);
+
+	ctrl->edid = drm_get_edid(connector, &ctrl->drm_aux->ddc);
+	if (!ctrl->edid) {
+		pr_err("%s: edid read fail\n", __func__);
+		goto disable_ret;
+	}
+
+	if (edid)
+		*edid = ctrl->edid;
+
+disable_ret:
+	if (!ctrl->power_on) {
+		edp_ctrl_irq_enable(ctrl, 0);
+		edp_ctrl_phy_aux_enable(ctrl, 0);
+	}
+unlock_ret:
+	mutex_unlock(&ctrl->dev_mutex);
+	return ret;
+}
+
+int msm_edp_ctrl_timing_cfg(struct edp_ctrl *ctrl,
+				const struct drm_display_mode *mode,
+				const struct drm_display_info *info)
+{
+	u32 hstart_from_sync, vstart_from_sync;
+	u32 data;
+	int ret = 0;
+
+	mutex_lock(&ctrl->dev_mutex);
+	/*
+	 * Need to keep color depth, pixel rate and
+	 * interlaced information in ctrl context
+	 */
+	ctrl->color_depth = info->bpc;
+	ctrl->pixel_rate = mode->clock;
+	ctrl->interlaced = !!(mode->flags & DRM_MODE_FLAG_INTERLACE);
+
+	/* Fill initial link config based on passed in timing */
+	edp_fill_link_cfg(ctrl);
+
+	if (edp_clk_enable(ctrl, EDP_CLK_MASK_AHB)) {
+		pr_err("%s, fail to prepare enable ahb clk\n", __func__);
+		ret = -EINVAL;
+		goto unlock_ret;
+	}
+	edp_clock_synchrous(ctrl, 1);
+
+	/* Configure eDP timing to HW */
+	edp_write(ctrl->base + REG_EDP_TOTAL_HOR_VER,
+		EDP_TOTAL_HOR_VER_HORIZ(mode->htotal) |
+		EDP_TOTAL_HOR_VER_VERT(mode->vtotal));
+
+	vstart_from_sync = mode->vtotal - mode->vsync_start;
+	hstart_from_sync = mode->htotal - mode->hsync_start;
+	edp_write(ctrl->base + REG_EDP_START_HOR_VER_FROM_SYNC,
+		EDP_START_HOR_VER_FROM_SYNC_HORIZ(hstart_from_sync) |
+		EDP_START_HOR_VER_FROM_SYNC_VERT(vstart_from_sync));
+
+	data = EDP_HSYNC_VSYNC_WIDTH_POLARITY_VERT(
+			mode->vsync_end - mode->vsync_start);
+	data |= EDP_HSYNC_VSYNC_WIDTH_POLARITY_HORIZ(
+			mode->hsync_end - mode->hsync_start);
+	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
+		data |= EDP_HSYNC_VSYNC_WIDTH_POLARITY_NVSYNC;
+	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
+		data |= EDP_HSYNC_VSYNC_WIDTH_POLARITY_NHSYNC;
+	edp_write(ctrl->base + REG_EDP_HSYNC_VSYNC_WIDTH_POLARITY, data);
+
+	edp_write(ctrl->base + REG_EDP_ACTIVE_HOR_VER,
+		EDP_ACTIVE_HOR_VER_HORIZ(mode->hdisplay) |
+		EDP_ACTIVE_HOR_VER_VERT(mode->vdisplay));
+
+	edp_clk_disable(ctrl, EDP_CLK_MASK_AHB);
+
+unlock_ret:
+	mutex_unlock(&ctrl->dev_mutex);
+	return ret;
+}
+
+bool msm_edp_ctrl_pixel_clock_valid(struct edp_ctrl *ctrl,
+	u32 pixel_rate, u32 *pm, u32 *pn)
+{
+	const struct edp_pixel_clk_div *divs;
+	u32 err = 1; /* 1% error tolerance */
+	u32 clk_err;
+	int i;
+
+	if (ctrl->link_rate == DP_LINK_BW_1_62) {
+		divs = clk_divs[0];
+	} else if (ctrl->link_rate == DP_LINK_BW_2_7) {
+		divs = clk_divs[1];
+	} else {
+		pr_err("%s: Invalid link rate,%d\n", __func__, ctrl->link_rate);
+		return false;
+	}
+
+	for (i = 0; i < EDP_PIXEL_CLK_NUM; i++) {
+		clk_err = abs(divs[i].rate - pixel_rate);
+		if ((divs[i].rate * err / 100) >= clk_err) {
+			if (pm)
+				*pm = divs[i].m;
+			if (pn)
+				*pn = divs[i].n;
+			return true;
+		}
+	}
+
+	DBG("pixel clock %d(kHz) not supported", pixel_rate);
+
+	return false;
+}
+

drivers/gpu/drm/msm/edp/edp_phy.c

···
+/*
+ * Copyright (c) 2014-2015, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include "edp.h"
+#include "edp.xml.h"
+
+#define EDP_MAX_LANE	4
+
+struct edp_phy {
+	void __iomem *base;
+};
+
+bool msm_edp_phy_ready(struct edp_phy *phy)
+{
+	u32 status;
+	int cnt = 100;
+
+	while (--cnt) {
+		status = edp_read(phy->base +
+				REG_EDP_PHY_GLB_PHY_STATUS);
+		if (status & 0x01)
+			break;
+		usleep_range(500, 1000);
+	}
+
+	if (cnt == 0) {
+		pr_err("%s: PHY NOT ready\n", __func__);
+		return false;
+	} else {
+		return true;
+	}
+}
+
+void msm_edp_phy_ctrl(struct edp_phy *phy, int enable)
+{
+	DBG("enable=%d", enable);
+	if (enable) {
+		/* Reset */
+		edp_write(phy->base + REG_EDP_PHY_CTRL,
+			EDP_PHY_CTRL_SW_RESET | EDP_PHY_CTRL_SW_RESET_PLL);
+		/* Make sure fully reset */
+		wmb();
+		usleep_range(500, 1000);
+		edp_write(phy->base + REG_EDP_PHY_CTRL, 0x000);
+		edp_write(phy->base + REG_EDP_PHY_GLB_PD_CTL, 0x3f);
+		edp_write(phy->base + REG_EDP_PHY_GLB_CFG, 0x1);
+	} else {
+		edp_write(phy->base + REG_EDP_PHY_GLB_PD_CTL, 0xc0);
+	}
+}
+
+/* voltage mode and pre emphasis cfg */
+void msm_edp_phy_vm_pe_init(struct edp_phy *phy)
+{
+	edp_write(phy->base + REG_EDP_PHY_GLB_VM_CFG0, 0x3);
+	edp_write(phy->base + REG_EDP_PHY_GLB_VM_CFG1, 0x64);
+	edp_write(phy->base + REG_EDP_PHY_GLB_MISC9, 0x6c);
+}
+
+void msm_edp_phy_vm_pe_cfg(struct edp_phy *phy, u32 v0, u32 v1)
+{
+	edp_write(phy->base + REG_EDP_PHY_GLB_VM_CFG0, v0);
+	edp_write(phy->base + REG_EDP_PHY_GLB_VM_CFG1, v1);
+}
+
+void msm_edp_phy_lane_power_ctrl(struct edp_phy *phy, bool up, u32 max_lane)
+{
+	u32 i;
+	u32 data;
+
+	if (up)
+		data = 0;	/* power up */
+	else
+		data = 0x7;	/* power down */
+
+	for (i = 0; i < max_lane; i++)
+		edp_write(phy->base + REG_EDP_PHY_LN_PD_CTL(i) , data);
+
+	/* power down unused lane */
+	data = 0x7;	/* power down */
+	for (i = max_lane; i < EDP_MAX_LANE; i++)
+		edp_write(phy->base + REG_EDP_PHY_LN_PD_CTL(i) , data);
+}
+
+void *msm_edp_phy_init(struct device *dev, void __iomem *regbase)
+{
+	struct edp_phy *phy = NULL;
+
+	phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL);
+	if (!phy)
+		return NULL;
+
+	phy->base = regbase;
+	return phy;
+}
+

drivers/gpu/drm/msm/msm_drv.h

···
 	 */
 	struct hdmi *hdmi;
 
+	/* eDP is for mdp5 only, but kms has not been created
+	 * when edp_bind() and edp_init() are called. Here is the only
+	 * place to keep the edp instance.
+	 */
+	struct msm_edp *edp;
+
 	/* when we have more than one 'msm_gpu' these need to be an array: */
 	struct msm_gpu *gpu;
 	struct msm_file_private *lastctx;