drivers/gpu/drm/bridge/display-connector.c - SHIFTPHONES/mainline/linux - Gitiles

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (C) 2019 Laurent Pinchart <laurent.pinchart@ideasonboard.com>
  */

 #include <linux/gpio/consumer.h>
 #include <linux/i2c.h>
 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/regulator/consumer.h>

 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_bridge.h>
 #include <drm/drm_edid.h>

 struct display_connector {
 	struct drm_bridge	bridge;

 	struct gpio_desc	*hpd_gpio;
 	int			hpd_irq;

 	struct regulator	*dp_pwr;
 };

 static inline struct display_connector *
 to_display_connector(struct drm_bridge *bridge)
 {
 	return container_of(bridge, struct display_connector, bridge);
 }

 static int display_connector_attach(struct drm_bridge *bridge,
 				    enum drm_bridge_attach_flags flags)
 {
 	return flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR ? 0 : -EINVAL;
 }

 static enum drm_connector_status
 display_connector_detect(struct drm_bridge *bridge)
 {
 	struct display_connector *conn = to_display_connector(bridge);

 	if (conn->hpd_gpio) {
 		if (gpiod_get_value_cansleep(conn->hpd_gpio))
 			return connector_status_connected;
 		else
 			return connector_status_disconnected;
 	}

 	if (conn->bridge.ddc && drm_probe_ddc(conn->bridge.ddc))
 		return connector_status_connected;

 	switch (conn->bridge.type) {
 	case DRM_MODE_CONNECTOR_DVIA:
 	case DRM_MODE_CONNECTOR_DVID:
 	case DRM_MODE_CONNECTOR_DVII:
 	case DRM_MODE_CONNECTOR_HDMIA:
 	case DRM_MODE_CONNECTOR_HDMIB:
 		/*
 		 * For DVI and HDMI connectors a DDC probe failure indicates
 		 * that no cable is connected.
 		 */
 		return connector_status_disconnected;

 	case DRM_MODE_CONNECTOR_Composite:
 	case DRM_MODE_CONNECTOR_SVIDEO:
 	case DRM_MODE_CONNECTOR_VGA:
 	default:
 		/*
 		 * Composite and S-Video connectors have no other detection
 		 * mean than the HPD GPIO. For VGA connectors, even if we have
 		 * an I2C bus, we can't assume that the cable is disconnected
 		 * if drm_probe_ddc fails, as some cables don't wire the DDC
 		 * pins.
 		 */
 		return connector_status_unknown;
 	}
 }

 static struct edid *display_connector_get_edid(struct drm_bridge *bridge,
 					       struct drm_connector *connector)
 {
 	struct display_connector *conn = to_display_connector(bridge);

 	return drm_get_edid(connector, conn->bridge.ddc);
 }

 /*
  * Since this bridge is tied to the connector, it acts like a passthrough,
  * so concerning the output bus formats, either pass the bus formats from the
  * previous bridge or return fallback data like done in the bridge function:
  * drm_atomic_bridge_chain_select_bus_fmts().
  * This supports negotiation if the bridge chain has all bits in place.
  */
 static u32 *display_connector_get_output_bus_fmts(struct drm_bridge *bridge,
 					struct drm_bridge_state *bridge_state,
 					struct drm_crtc_state *crtc_state,
 					struct drm_connector_state *conn_state,
 					unsigned int *num_output_fmts)
 {
 	struct drm_bridge *prev_bridge = drm_bridge_get_prev_bridge(bridge);
 	struct drm_bridge_state *prev_bridge_state;

 	if (!prev_bridge || !prev_bridge->funcs->atomic_get_output_bus_fmts) {
 		struct drm_connector *conn = conn_state->connector;
 		u32 *out_bus_fmts;

 		*num_output_fmts = 1;
 		out_bus_fmts = kmalloc(sizeof(*out_bus_fmts), GFP_KERNEL);
 		if (!out_bus_fmts)
 			return NULL;

 		if (conn->display_info.num_bus_formats &&
 		    conn->display_info.bus_formats)
 			out_bus_fmts[0] = conn->display_info.bus_formats[0];
 		else
 			out_bus_fmts[0] = MEDIA_BUS_FMT_FIXED;

 		return out_bus_fmts;
 	}

 	prev_bridge_state = drm_atomic_get_new_bridge_state(crtc_state->state,
 							    prev_bridge);

 	return prev_bridge->funcs->atomic_get_output_bus_fmts(prev_bridge, prev_bridge_state,
 							      crtc_state, conn_state,
 							      num_output_fmts);
 }

 /*
  * Since this bridge is tied to the connector, it acts like a passthrough,
  * so concerning the input bus formats, either pass the bus formats from the
  * previous bridge or MEDIA_BUS_FMT_FIXED (like select_bus_fmt_recursive())
  * when atomic_get_input_bus_fmts is not supported.
  * This supports negotiation if the bridge chain has all bits in place.
  */
 static u32 *display_connector_get_input_bus_fmts(struct drm_bridge *bridge,
 					struct drm_bridge_state *bridge_state,
 					struct drm_crtc_state *crtc_state,
 					struct drm_connector_state *conn_state,
 					u32 output_fmt,
 					unsigned int *num_input_fmts)
 {
 	struct drm_bridge *prev_bridge = drm_bridge_get_prev_bridge(bridge);
 	struct drm_bridge_state *prev_bridge_state;

 	if (!prev_bridge || !prev_bridge->funcs->atomic_get_input_bus_fmts) {
 		u32 *in_bus_fmts;

 		*num_input_fmts = 1;
 		in_bus_fmts = kmalloc(sizeof(*in_bus_fmts), GFP_KERNEL);
 		if (!in_bus_fmts)
 			return NULL;

 		in_bus_fmts[0] = MEDIA_BUS_FMT_FIXED;

 		return in_bus_fmts;
 	}

 	prev_bridge_state = drm_atomic_get_new_bridge_state(crtc_state->state,
 							    prev_bridge);

 	return prev_bridge->funcs->atomic_get_input_bus_fmts(prev_bridge, prev_bridge_state,
 							     crtc_state, conn_state, output_fmt,
 							     num_input_fmts);
 }

 static const struct drm_bridge_funcs display_connector_bridge_funcs = {
 	.attach = display_connector_attach,
 	.detect = display_connector_detect,
 	.get_edid = display_connector_get_edid,
 	.atomic_get_output_bus_fmts = display_connector_get_output_bus_fmts,
 	.atomic_get_input_bus_fmts = display_connector_get_input_bus_fmts,
 	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
 	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
 	.atomic_reset = drm_atomic_helper_bridge_reset,
 };

 static irqreturn_t display_connector_hpd_irq(int irq, void *arg)
 {
 	struct display_connector *conn = arg;
 	struct drm_bridge *bridge = &conn->bridge;

 	drm_bridge_hpd_notify(bridge, display_connector_detect(bridge));

 	return IRQ_HANDLED;
 }

 static int display_connector_probe(struct platform_device *pdev)
 {
 	struct display_connector *conn;
 	unsigned int type;
 	const char *label = NULL;
 	int ret;

 	conn = devm_kzalloc(&pdev->dev, sizeof(*conn), GFP_KERNEL);
 	if (!conn)
 		return -ENOMEM;

 	platform_set_drvdata(pdev, conn);

 	type = (uintptr_t)of_device_get_match_data(&pdev->dev);

 	/* Get the exact connector type. */
 	switch (type) {
 	case DRM_MODE_CONNECTOR_DVII: {
 		bool analog, digital;

 		analog = of_property_read_bool(pdev->dev.of_node, "analog");
 		digital = of_property_read_bool(pdev->dev.of_node, "digital");
 		if (analog && !digital) {
 			conn->bridge.type = DRM_MODE_CONNECTOR_DVIA;
 		} else if (!analog && digital) {
 			conn->bridge.type = DRM_MODE_CONNECTOR_DVID;
 		} else if (analog && digital) {
 			conn->bridge.type = DRM_MODE_CONNECTOR_DVII;
 		} else {
 			dev_err(&pdev->dev, "DVI connector with no type\n");
 			return -EINVAL;
 		}
 		break;
 	}

 	case DRM_MODE_CONNECTOR_HDMIA: {
 		const char *hdmi_type;

 		ret = of_property_read_string(pdev->dev.of_node, "type",
 					      &hdmi_type);
 		if (ret < 0) {
 			dev_err(&pdev->dev, "HDMI connector with no type\n");
 			return -EINVAL;
 		}

 		if (!strcmp(hdmi_type, "a") || !strcmp(hdmi_type, "c") ||
 		    !strcmp(hdmi_type, "d") || !strcmp(hdmi_type, "e")) {
 			conn->bridge.type = DRM_MODE_CONNECTOR_HDMIA;
 		} else if (!strcmp(hdmi_type, "b")) {
 			conn->bridge.type = DRM_MODE_CONNECTOR_HDMIB;
 		} else {
 			dev_err(&pdev->dev,
 				"Unsupported HDMI connector type '%s'\n",
 				hdmi_type);
 			return -EINVAL;
 		}

 		break;
 	}

 	default:
 		conn->bridge.type = type;
 		break;
 	}

 	/* All the supported connector types support interlaced modes. */
 	conn->bridge.interlace_allowed = true;

 	/* Get the optional connector label. */
 	of_property_read_string(pdev->dev.of_node, "label", &label);

 	/*
 	 * Get the HPD GPIO for DVI, HDMI and DP connectors. If the GPIO can provide
 	 * edge interrupts, register an interrupt handler.
 	 */
 	if (type == DRM_MODE_CONNECTOR_DVII ||
 	    type == DRM_MODE_CONNECTOR_HDMIA ||
 	    type == DRM_MODE_CONNECTOR_DisplayPort) {
 		conn->hpd_gpio = devm_gpiod_get_optional(&pdev->dev, "hpd",
 							 GPIOD_IN);
 		if (IS_ERR(conn->hpd_gpio)) {
 			if (PTR_ERR(conn->hpd_gpio) != -EPROBE_DEFER)
 				dev_err(&pdev->dev,
 					"Unable to retrieve HPD GPIO\n");
 			return PTR_ERR(conn->hpd_gpio);
 		}

 		conn->hpd_irq = gpiod_to_irq(conn->hpd_gpio);
 	} else {
 		conn->hpd_irq = -EINVAL;
 	}

 	if (conn->hpd_irq >= 0) {
 		ret = devm_request_threaded_irq(&pdev->dev, conn->hpd_irq,
 						NULL, display_connector_hpd_irq,
 						IRQF_TRIGGER_RISING |
 						IRQF_TRIGGER_FALLING |
 						IRQF_ONESHOT,
 						"HPD", conn);
 		if (ret) {
 			dev_info(&pdev->dev,
 				 "Failed to request HPD edge interrupt, falling back to polling\n");
 			conn->hpd_irq = -EINVAL;
 		}
 	}

 	/* Retrieve the DDC I2C adapter for DVI, HDMI and VGA connectors. */
 	if (type == DRM_MODE_CONNECTOR_DVII ||
 	    type == DRM_MODE_CONNECTOR_HDMIA ||
 	    type == DRM_MODE_CONNECTOR_VGA) {
 		struct device_node *phandle;

 		phandle = of_parse_phandle(pdev->dev.of_node, "ddc-i2c-bus", 0);
 		if (phandle) {
 			conn->bridge.ddc = of_get_i2c_adapter_by_node(phandle);
 			of_node_put(phandle);
 			if (!conn->bridge.ddc)
 				return -EPROBE_DEFER;
 		} else {
 			dev_dbg(&pdev->dev,
 				"No I2C bus specified, disabling EDID readout\n");
 		}
 	}

 	/* Get the DP PWR for DP connector. */
 	if (type == DRM_MODE_CONNECTOR_DisplayPort) {
 		int ret;

 		conn->dp_pwr = devm_regulator_get_optional(&pdev->dev, "dp-pwr");

 		if (IS_ERR(conn->dp_pwr)) {
 			ret = PTR_ERR(conn->dp_pwr);

 			switch (ret) {
 			case -ENODEV:
 				conn->dp_pwr = NULL;
 				break;

 			case -EPROBE_DEFER:
 				return -EPROBE_DEFER;

 			default:
 				dev_err(&pdev->dev, "failed to get DP PWR regulator: %d\n", ret);
 				return ret;
 			}
 		}

 		if (conn->dp_pwr) {
 			ret = regulator_enable(conn->dp_pwr);
 			if (ret) {
 				dev_err(&pdev->dev, "failed to enable DP PWR regulator: %d\n", ret);
 				return ret;
 			}
 		}
 	}

 	conn->bridge.funcs = &display_connector_bridge_funcs;
 	conn->bridge.of_node = pdev->dev.of_node;

 	if (conn->bridge.ddc)
 		conn->bridge.ops |= DRM_BRIDGE_OP_EDID
 				 |  DRM_BRIDGE_OP_DETECT;
 	if (conn->hpd_gpio)
 		conn->bridge.ops |= DRM_BRIDGE_OP_DETECT;
 	if (conn->hpd_irq >= 0)
 		conn->bridge.ops |= DRM_BRIDGE_OP_HPD;

 	dev_dbg(&pdev->dev,
 		"Found %s display connector '%s' %s DDC bus and %s HPD GPIO (ops 0x%x)\n",
 		drm_get_connector_type_name(conn->bridge.type),
 		label ? label : "<unlabelled>",
 		conn->bridge.ddc ? "with" : "without",
 		conn->hpd_gpio ? "with" : "without",
 		conn->bridge.ops);

 	drm_bridge_add(&conn->bridge);

 	return 0;
 }

 static int display_connector_remove(struct platform_device *pdev)
 {
 	struct display_connector *conn = platform_get_drvdata(pdev);

 	if (conn->dp_pwr)
 		regulator_disable(conn->dp_pwr);

 	drm_bridge_remove(&conn->bridge);

 	if (!IS_ERR(conn->bridge.ddc))
 		i2c_put_adapter(conn->bridge.ddc);

 	return 0;
 }

 static const struct of_device_id display_connector_match[] = {
 	{
 		.compatible = "composite-video-connector",
 		.data = (void *)DRM_MODE_CONNECTOR_Composite,
 	}, {
 		.compatible = "dvi-connector",
 		.data = (void *)DRM_MODE_CONNECTOR_DVII,
 	}, {
 		.compatible = "hdmi-connector",
 		.data = (void *)DRM_MODE_CONNECTOR_HDMIA,
 	}, {
 		.compatible = "svideo-connector",
 		.data = (void *)DRM_MODE_CONNECTOR_SVIDEO,
 	}, {
 		.compatible = "vga-connector",
 		.data = (void *)DRM_MODE_CONNECTOR_VGA,
 	}, {
 		.compatible = "dp-connector",
 		.data = (void *)DRM_MODE_CONNECTOR_DisplayPort,
 	},
 	{},
 };
 MODULE_DEVICE_TABLE(of, display_connector_match);

 static struct platform_driver display_connector_driver = {
 	.probe	= display_connector_probe,
 	.remove	= display_connector_remove,
 	.driver		= {
 		.name		= "display-connector",
 		.of_match_table	= display_connector_match,
 	},
 };
 module_platform_driver(display_connector_driver);

 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
 MODULE_DESCRIPTION("Display connector driver");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Copyright (C) 2019 Laurent Pinchart <laurent.pinchart@ideasonboard.com>
	*/

	#include <linux/gpio/consumer.h>
	#include <linux/i2c.h>
	#include <linux/interrupt.h>
	#include <linux/module.h>
	#include <linux/mutex.h>
	#include <linux/of.h>
	#include <linux/of_device.h>
	#include <linux/platform_device.h>
	#include <linux/regulator/consumer.h>

	#include <drm/drm_atomic_helper.h>
	#include <drm/drm_bridge.h>
	#include <drm/drm_edid.h>

	struct display_connector {
	struct drm_bridge bridge;

	struct gpio_desc *hpd_gpio;
	int hpd_irq;

	struct regulator *dp_pwr;
	};

	static inline struct display_connector *
	to_display_connector(struct drm_bridge *bridge)
	{
	return container_of(bridge, struct display_connector, bridge);
	}

	static int display_connector_attach(struct drm_bridge *bridge,
	enum drm_bridge_attach_flags flags)
	{
	return flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR ? 0 : -EINVAL;
	}

	static enum drm_connector_status
	display_connector_detect(struct drm_bridge *bridge)
	{
	struct display_connector *conn = to_display_connector(bridge);

	if (conn->hpd_gpio) {
	if (gpiod_get_value_cansleep(conn->hpd_gpio))
	return connector_status_connected;
	else
	return connector_status_disconnected;
	}

	if (conn->bridge.ddc && drm_probe_ddc(conn->bridge.ddc))
	return connector_status_connected;

	switch (conn->bridge.type) {
	case DRM_MODE_CONNECTOR_DVIA:
	case DRM_MODE_CONNECTOR_DVID:
	case DRM_MODE_CONNECTOR_DVII:
	case DRM_MODE_CONNECTOR_HDMIA:
	case DRM_MODE_CONNECTOR_HDMIB:
	/*
	* For DVI and HDMI connectors a DDC probe failure indicates
	* that no cable is connected.
	*/
	return connector_status_disconnected;

	case DRM_MODE_CONNECTOR_Composite:
	case DRM_MODE_CONNECTOR_SVIDEO:
	case DRM_MODE_CONNECTOR_VGA:
	default:
	/*
	* Composite and S-Video connectors have no other detection
	* mean than the HPD GPIO. For VGA connectors, even if we have
	* an I2C bus, we can't assume that the cable is disconnected
	* if drm_probe_ddc fails, as some cables don't wire the DDC
	* pins.
	*/
	return connector_status_unknown;
	}
	}

	static struct edid display_connector_get_edid(struct drm_bridge bridge,
	struct drm_connector *connector)
	{
	struct display_connector *conn = to_display_connector(bridge);

	return drm_get_edid(connector, conn->bridge.ddc);
	}

	/*
	* Since this bridge is tied to the connector, it acts like a passthrough,
	* so concerning the output bus formats, either pass the bus formats from the
	* previous bridge or return fallback data like done in the bridge function:
	* drm_atomic_bridge_chain_select_bus_fmts().
	* This supports negotiation if the bridge chain has all bits in place.
	*/
	static u32 display_connector_get_output_bus_fmts(struct drm_bridge bridge,
	struct drm_bridge_state *bridge_state,
	struct drm_crtc_state *crtc_state,
	struct drm_connector_state *conn_state,
	unsigned int *num_output_fmts)
	{
	struct drm_bridge *prev_bridge = drm_bridge_get_prev_bridge(bridge);
	struct drm_bridge_state *prev_bridge_state;

	if (!prev_bridge \|\| !prev_bridge->funcs->atomic_get_output_bus_fmts) {
	struct drm_connector *conn = conn_state->connector;
	u32 *out_bus_fmts;

	*num_output_fmts = 1;
	out_bus_fmts = kmalloc(sizeof(*out_bus_fmts), GFP_KERNEL);
	if (!out_bus_fmts)
	return NULL;

	if (conn->display_info.num_bus_formats &&
	conn->display_info.bus_formats)
	out_bus_fmts[0] = conn->display_info.bus_formats[0];
	else
	out_bus_fmts[0] = MEDIA_BUS_FMT_FIXED;

	return out_bus_fmts;
	}

	prev_bridge_state = drm_atomic_get_new_bridge_state(crtc_state->state,
	prev_bridge);

	return prev_bridge->funcs->atomic_get_output_bus_fmts(prev_bridge, prev_bridge_state,
	crtc_state, conn_state,
	num_output_fmts);
	}

	/*
	* Since this bridge is tied to the connector, it acts like a passthrough,
	* so concerning the input bus formats, either pass the bus formats from the
	* previous bridge or MEDIA_BUS_FMT_FIXED (like select_bus_fmt_recursive())
	* when atomic_get_input_bus_fmts is not supported.
	* This supports negotiation if the bridge chain has all bits in place.
	*/
	static u32 display_connector_get_input_bus_fmts(struct drm_bridge bridge,
	struct drm_bridge_state *bridge_state,
	struct drm_crtc_state *crtc_state,
	struct drm_connector_state *conn_state,
	u32 output_fmt,
	unsigned int *num_input_fmts)
	{
	struct drm_bridge *prev_bridge = drm_bridge_get_prev_bridge(bridge);
	struct drm_bridge_state *prev_bridge_state;

	if (!prev_bridge \|\| !prev_bridge->funcs->atomic_get_input_bus_fmts) {
	u32 *in_bus_fmts;

	*num_input_fmts = 1;
	in_bus_fmts = kmalloc(sizeof(*in_bus_fmts), GFP_KERNEL);
	if (!in_bus_fmts)
	return NULL;

	in_bus_fmts[0] = MEDIA_BUS_FMT_FIXED;

	return in_bus_fmts;
	}

	prev_bridge_state = drm_atomic_get_new_bridge_state(crtc_state->state,
	prev_bridge);

	return prev_bridge->funcs->atomic_get_input_bus_fmts(prev_bridge, prev_bridge_state,
	crtc_state, conn_state, output_fmt,
	num_input_fmts);
	}

	static const struct drm_bridge_funcs display_connector_bridge_funcs = {
	.attach = display_connector_attach,
	.detect = display_connector_detect,
	.get_edid = display_connector_get_edid,
	.atomic_get_output_bus_fmts = display_connector_get_output_bus_fmts,
	.atomic_get_input_bus_fmts = display_connector_get_input_bus_fmts,
	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
	.atomic_reset = drm_atomic_helper_bridge_reset,
	};

	static irqreturn_t display_connector_hpd_irq(int irq, void *arg)
	{
	struct display_connector *conn = arg;
	struct drm_bridge *bridge = &conn->bridge;

	drm_bridge_hpd_notify(bridge, display_connector_detect(bridge));

	return IRQ_HANDLED;
	}

	static int display_connector_probe(struct platform_device *pdev)
	{
	struct display_connector *conn;
	unsigned int type;
	const char *label = NULL;
	int ret;

	conn = devm_kzalloc(&pdev->dev, sizeof(*conn), GFP_KERNEL);
	if (!conn)
	return -ENOMEM;

	platform_set_drvdata(pdev, conn);

	type = (uintptr_t)of_device_get_match_data(&pdev->dev);

	/* Get the exact connector type. */
	switch (type) {
	case DRM_MODE_CONNECTOR_DVII: {
	bool analog, digital;

	analog = of_property_read_bool(pdev->dev.of_node, "analog");
	digital = of_property_read_bool(pdev->dev.of_node, "digital");
	if (analog && !digital) {
	conn->bridge.type = DRM_MODE_CONNECTOR_DVIA;
	} else if (!analog && digital) {
	conn->bridge.type = DRM_MODE_CONNECTOR_DVID;
	} else if (analog && digital) {
	conn->bridge.type = DRM_MODE_CONNECTOR_DVII;
	} else {
	dev_err(&pdev->dev, "DVI connector with no type\n");
	return -EINVAL;
	}
	break;
	}

	case DRM_MODE_CONNECTOR_HDMIA: {
	const char *hdmi_type;

	ret = of_property_read_string(pdev->dev.of_node, "type",
	&hdmi_type);
	if (ret < 0) {
	dev_err(&pdev->dev, "HDMI connector with no type\n");
	return -EINVAL;
	}

	if (!strcmp(hdmi_type, "a") \|\| !strcmp(hdmi_type, "c") \|\|
	!strcmp(hdmi_type, "d") \|\| !strcmp(hdmi_type, "e")) {
	conn->bridge.type = DRM_MODE_CONNECTOR_HDMIA;
	} else if (!strcmp(hdmi_type, "b")) {
	conn->bridge.type = DRM_MODE_CONNECTOR_HDMIB;
	} else {
	dev_err(&pdev->dev,
	"Unsupported HDMI connector type '%s'\n",
	hdmi_type);
	return -EINVAL;
	}

	break;
	}

	default:
	conn->bridge.type = type;
	break;
	}

	/* All the supported connector types support interlaced modes. */
	conn->bridge.interlace_allowed = true;

	/* Get the optional connector label. */
	of_property_read_string(pdev->dev.of_node, "label", &label);

	/*
	* Get the HPD GPIO for DVI, HDMI and DP connectors. If the GPIO can provide
	* edge interrupts, register an interrupt handler.
	*/
	if (type == DRM_MODE_CONNECTOR_DVII \|\|
	type == DRM_MODE_CONNECTOR_HDMIA \|\|
	type == DRM_MODE_CONNECTOR_DisplayPort) {
	conn->hpd_gpio = devm_gpiod_get_optional(&pdev->dev, "hpd",
	GPIOD_IN);
	if (IS_ERR(conn->hpd_gpio)) {
	if (PTR_ERR(conn->hpd_gpio) != -EPROBE_DEFER)
	dev_err(&pdev->dev,
	"Unable to retrieve HPD GPIO\n");
	return PTR_ERR(conn->hpd_gpio);
	}

	conn->hpd_irq = gpiod_to_irq(conn->hpd_gpio);
	} else {
	conn->hpd_irq = -EINVAL;
	}

	if (conn->hpd_irq >= 0) {
	ret = devm_request_threaded_irq(&pdev->dev, conn->hpd_irq,
	NULL, display_connector_hpd_irq,
	IRQF_TRIGGER_RISING \|
	IRQF_TRIGGER_FALLING \|
	IRQF_ONESHOT,
	"HPD", conn);
	if (ret) {
	dev_info(&pdev->dev,
	"Failed to request HPD edge interrupt, falling back to polling\n");
	conn->hpd_irq = -EINVAL;
	}
	}

	/* Retrieve the DDC I2C adapter for DVI, HDMI and VGA connectors. */
	if (type == DRM_MODE_CONNECTOR_DVII \|\|
	type == DRM_MODE_CONNECTOR_HDMIA \|\|
	type == DRM_MODE_CONNECTOR_VGA) {
	struct device_node *phandle;

	phandle = of_parse_phandle(pdev->dev.of_node, "ddc-i2c-bus", 0);
	if (phandle) {
	conn->bridge.ddc = of_get_i2c_adapter_by_node(phandle);
	of_node_put(phandle);
	if (!conn->bridge.ddc)
	return -EPROBE_DEFER;
	} else {
	dev_dbg(&pdev->dev,
	"No I2C bus specified, disabling EDID readout\n");
	}
	}

	/* Get the DP PWR for DP connector. */
	if (type == DRM_MODE_CONNECTOR_DisplayPort) {
	int ret;

	conn->dp_pwr = devm_regulator_get_optional(&pdev->dev, "dp-pwr");

	if (IS_ERR(conn->dp_pwr)) {
	ret = PTR_ERR(conn->dp_pwr);

	switch (ret) {
	case -ENODEV:
	conn->dp_pwr = NULL;
	break;

	case -EPROBE_DEFER:
	return -EPROBE_DEFER;

	default:
	dev_err(&pdev->dev, "failed to get DP PWR regulator: %d\n", ret);
	return ret;
	}
	}

	if (conn->dp_pwr) {
	ret = regulator_enable(conn->dp_pwr);
	if (ret) {
	dev_err(&pdev->dev, "failed to enable DP PWR regulator: %d\n", ret);
	return ret;
	}
	}
	}

	conn->bridge.funcs = &display_connector_bridge_funcs;
	conn->bridge.of_node = pdev->dev.of_node;

	if (conn->bridge.ddc)
	conn->bridge.ops \|= DRM_BRIDGE_OP_EDID
	\| DRM_BRIDGE_OP_DETECT;
	if (conn->hpd_gpio)
	conn->bridge.ops \|= DRM_BRIDGE_OP_DETECT;
	if (conn->hpd_irq >= 0)
	conn->bridge.ops \|= DRM_BRIDGE_OP_HPD;

	dev_dbg(&pdev->dev,
	"Found %s display connector '%s' %s DDC bus and %s HPD GPIO (ops 0x%x)\n",
	drm_get_connector_type_name(conn->bridge.type),
	label ? label : "<unlabelled>",
	conn->bridge.ddc ? "with" : "without",
	conn->hpd_gpio ? "with" : "without",
	conn->bridge.ops);

	drm_bridge_add(&conn->bridge);

	return 0;
	}

	static int display_connector_remove(struct platform_device *pdev)
	{
	struct display_connector *conn = platform_get_drvdata(pdev);

	if (conn->dp_pwr)
	regulator_disable(conn->dp_pwr);

	drm_bridge_remove(&conn->bridge);

	if (!IS_ERR(conn->bridge.ddc))
	i2c_put_adapter(conn->bridge.ddc);

	return 0;
	}

	static const struct of_device_id display_connector_match[] = {
	{
	.compatible = "composite-video-connector",
	.data = (void *)DRM_MODE_CONNECTOR_Composite,
	}, {
	.compatible = "dvi-connector",
	.data = (void *)DRM_MODE_CONNECTOR_DVII,
	}, {
	.compatible = "hdmi-connector",
	.data = (void *)DRM_MODE_CONNECTOR_HDMIA,
	}, {
	.compatible = "svideo-connector",
	.data = (void *)DRM_MODE_CONNECTOR_SVIDEO,
	}, {
	.compatible = "vga-connector",
	.data = (void *)DRM_MODE_CONNECTOR_VGA,
	}, {
	.compatible = "dp-connector",
	.data = (void *)DRM_MODE_CONNECTOR_DisplayPort,
	},
	{},
	};
	MODULE_DEVICE_TABLE(of, display_connector_match);

	static struct platform_driver display_connector_driver = {
	.probe = display_connector_probe,
	.remove = display_connector_remove,
	.driver = {
	.name = "display-connector",
	.of_match_table = display_connector_match,
	},
	};
	module_platform_driver(display_connector_driver);

	MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
	MODULE_DESCRIPTION("Display connector driver");
	MODULE_LICENSE("GPL");