1 files changed, 439 insertions, 0 deletions

diff --git a/drivers/gpu/drm/bridge/display-connector.c b/drivers/gpu/drm/bridge/display-connector.c
new file mode 100644
index 000000000..9a12449ad
--- /dev/null
+++ b/drivers/gpu/drm/bridge/display-connector.c
@@ -0,0 +1,439 @@
+// 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/media-bus-format.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;
+	struct gpio_desc	*ddc_en;
+};
+
+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;
+			}
+		}
+	}
+
+	/* enable DDC */
+	if (type == DRM_MODE_CONNECTOR_HDMIA) {
+		conn->ddc_en = devm_gpiod_get_optional(&pdev->dev, "ddc-en",
+						       GPIOD_OUT_HIGH);
+
+		if (IS_ERR(conn->ddc_en)) {
+			dev_err(&pdev->dev, "Couldn't get ddc-en gpio\n");
+			return PTR_ERR(conn->ddc_en);
+		}
+	}
+
+	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->ddc_en)
+		gpiod_set_value(conn->ddc_en, 0);
+
+	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");