--- /dev/null
+// 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 <drm/drm_bridge.h>
+#include <drm/drm_edid.h>
+
+struct display_connector {
+ struct drm_bridge bridge;
+
+ struct gpio_desc *hpd_gpio;
+ int hpd_irq;
+};
+
+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);
+}
+
+static const struct drm_bridge_funcs display_connector_bridge_funcs = {
+ .attach = display_connector_attach,
+ .detect = display_connector_detect,
+ .get_edid = display_connector_get_edid,
+};
+
+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;
+ 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 and HDMI connectors. If the GPIO can provide
+ * edge interrupts, register an interrupt handler.
+ */
+ if (type == DRM_MODE_CONNECTOR_DVII ||
+ type == DRM_MODE_CONNECTOR_HDMIA) {
+ 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");
+ }
+ }
+
+ 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);
+
+ 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,
+ },
+ {},
+};
+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");
projects / openwrt / staging / blogic.git / commitdiff