drm/imx/hdp: add HDMI CTRL GPIO support

Add support to control HDMI levels using a GPIO. The driver simply
sets the GPIO high for HDMI and low for DisplayPort.

Signed-off-by: Stefan Agner <stefan.agner@toradex.com>

2 files changed, 28 insertions, 3 deletions

diff --git a/drivers/gpu/drm/imx/hdp/imx-hdp.c b/drivers/gpu/drm/imx/hdp/imx-hdp.c
index 0a998e5487cf..098cc6de87e1 100644
--- a/drivers/gpu/drm/imx/hdp/imx-hdp.c
+++ b/drivers/gpu/drm/imx/hdp/imx-hdp.c
@@ -20,6 +20,7 @@
 #include <linux/of.h>
 #include <linux/irq.h>
 #include <linux/of_device.h>
+#include <linux/of_gpio.h>
 
 #include "imx-hdp.h"
 #include "imx-hdmi.h"
@@ -934,6 +935,7 @@ static struct hdp_ops imx8qm_hdmi_ops = {
 static struct hdp_devtype imx8qm_dp_devtype = {
 	.is_edid = false,
 	.is_4kp60 = false,
+	.is_hdmi_level = false,
 	.audio_type = CDN_DPTX,
 	.ops = &imx8qm_dp_ops,
 	.rw = &imx8qm_rw,
@@ -942,6 +944,7 @@ static struct hdp_devtype imx8qm_dp_devtype = {
 static struct hdp_devtype imx8qm_hdmi_devtype = {
 	.is_edid = false,
 	.is_4kp60 = false,
+	.is_hdmi_level = true,
 	.audio_type = CDN_HDMITX_TYPHOON,
 	.ops = &imx8qm_hdmi_ops,
 	.rw = &imx8qm_rw,
@@ -964,6 +967,7 @@ static struct hdp_ops imx8mq_ops = {
 static struct hdp_devtype imx8mq_hdmi_devtype = {
 	.is_edid = false,
 	.is_4kp60 = true,
+	.is_hdmi_level = true,
 	.audio_type = CDN_HDMITX_KIRAN,
 	.ops = &imx8mq_ops,
 	.rw = &imx8mq_rw,
@@ -1159,6 +1163,18 @@ static int imx_hdp_imx_bind(struct device *dev, struct device *master,
 
 	INIT_DELAYED_WORK(&hdp->hotplug_work, hotplug_work_func);
 
+	hdp->hdmi_ctrl_gpio = of_get_named_gpio(dev->of_node, "hdmi-ctrl-gpios", 0);
+	if (gpio_is_valid(hdp->hdmi_ctrl_gpio)) {
+		ret = gpio_request(hdp->hdmi_ctrl_gpio, "HDMI_CTRL");
+		if (ret < 0) {
+			dev_err(dev, "request HDMI CTRL GPIO failed: %d\n", ret);
+			goto err_cleanup_encoder;
+		}
+
+		/* Set signals depending on HDP device type */
+		gpio_direction_output(hdp->hdmi_ctrl_gpio, devtype->is_hdmi_level);
+	}
+
 	/* Check cable states before enable irq */
 	imx_hdp_call(hdp, get_hpd_state, &hdp->state, &hpd);
 
@@ -1171,7 +1187,7 @@ static int imx_hdp_imx_bind(struct device *dev, struct device *master,
 		if (ret) {
 			dev_err(&pdev->dev, "can't claim irq %d\n",
 							hdp->irq[HPD_IRQ_IN]);
-			goto err_irq;
+			goto err_free_hdmi_gpio;
 		}
 		/* Cable Disconnedted, enable Plug in IRQ */
 		if (hpd == 0)
@@ -1185,7 +1201,7 @@ static int imx_hdp_imx_bind(struct device *dev, struct device *master,
 		if (ret) {
 			dev_err(&pdev->dev, "can't claim irq %d\n",
 							hdp->irq[HPD_IRQ_OUT]);
-			goto err_irq;
+			goto err_free_hdmi_gpio;
 		}
 		/* Cable Connected, enable Plug out IRQ */
 		if (hpd == 1)
@@ -1193,7 +1209,11 @@ static int imx_hdp_imx_bind(struct device *dev, struct device *master,
 	}
 
 	return 0;
-err_irq:
+
+err_free_hdmi_gpio:
+	if (gpio_is_valid(hdp->hdmi_ctrl_gpio))
+		gpio_free(hdp->hdmi_ctrl_gpio);
+err_cleanup_encoder:
 	drm_encoder_cleanup(encoder);
 	return ret;
 }
@@ -1206,6 +1226,9 @@ static void imx_hdp_imx_unbind(struct device *dev, struct device *master,
 	imx_hdp_call(hdp, pixel_clock_disable, &hdp->clks);
 	imx_hdp_call(hdp, pixel_link_deinit, &hdp->state);
 	drm_bridge_detach(&hdp->bridge);
+
+	if (gpio_is_valid(hdp->hdmi_ctrl_gpio))
+		gpio_free(hdp->hdmi_ctrl_gpio);
 }
 
 static const struct component_ops imx_hdp_imx_ops = {
diff --git a/drivers/gpu/drm/imx/hdp/imx-hdp.h b/drivers/gpu/drm/imx/hdp/imx-hdp.h
index 5ece81345aa4..af0f81bbaf02 100644
--- a/drivers/gpu/drm/imx/hdp/imx-hdp.h
+++ b/drivers/gpu/drm/imx/hdp/imx-hdp.h
@@ -107,6 +107,7 @@ struct hdp_ops {
 struct hdp_devtype {
 	u8 is_edid;
 	u8 is_4kp60;
+	u8 is_hdmi_level;
 	u8 audio_type;
 	struct hdp_ops *ops;
 	struct hdp_rw_func *rw;
@@ -191,6 +192,7 @@ struct imx_hdp {
 
 	struct edid *edid;
 	char cable_state;
+	int hdmi_ctrl_gpio;
 
 	void __iomem *regs_base; /* Controller regs base */
 	void __iomem *ss_base; /* HDP Subsystem regs base */