drm/bridge: tfp410: Replace manual connector handling with bridge

Now that a driver is available for display connectors, replace the
manual connector handling code with usage of the DRM bridge API. The
tfp410 driver doesn't deal with the display connector directly anymore,
but still delegates drm_connector operations to the next bridge. This
brings us one step closer to having the tfp410 driver handling the
TFP410 only.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Tested-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200226112514.12455-19-laurent.pinchart@ideasonboard.com

drivers/gpu/drm/bridge/ti-tfp410.c

@@ -4,14 +4,12 @@
  * Author: Jyri Sarha <jsarha@ti.com>
  */
 
-#include <linux/delay.h>
-#include <linux/fwnode.h>
 #include <linux/gpio/consumer.h>
 #include <linux/i2c.h>
-#include <linux/irq.h>
 #include <linux/module.h>
 #include <linux/of_graph.h>
 #include <linux/platform_device.h>
+#include <linux/workqueue.h>
 
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_bridge.h>
@@ -24,16 +22,13 @@
 struct tfp410 {
 	struct drm_bridge	bridge;
 	struct drm_connector	connector;
-	unsigned int		connector_type;
 
 	u32			bus_format;
-	struct i2c_adapter	*ddc;
-	struct gpio_desc	*hpd;
-	int			hpd_irq;
 	struct delayed_work	hpd_work;
 	struct gpio_desc	*powerdown;
 
 	struct drm_bridge_timings timings;
+	struct drm_bridge	*next_bridge;
 
 	struct device *dev;
 };
@@ -56,13 +51,18 @@ static int tfp410_get_modes(struct drm_connector *connector)
 	struct edid *edid;
 	int ret;
 
-	if (!dvi->ddc)
-		goto fallback;
-
-	edid = drm_get_edid(connector, dvi->ddc);
-	if (!edid) {
+	edid = drm_bridge_get_edid(dvi->next_bridge, connector);
+	if (IS_ERR_OR_NULL(edid)) {
+		if (edid != ERR_PTR(-ENOTSUPP))
 			DRM_INFO("EDID read failed. Fallback to standard modes\n");
-		goto fallback;
+
+		/*
+		 * No EDID, fallback on the XGA standard modes and prefer a mode
+		 * pretty much anything can handle.
+		 */
+		ret = drm_add_modes_noedid(connector, 1920, 1200);
+		drm_set_preferred_mode(connector, 1024, 768);
+		return ret;
 	}
 
 	drm_connector_update_edid_property(connector, edid);
@@ -71,15 +71,6 @@ static int tfp410_get_modes(struct drm_connector *connector)
 
 	kfree(edid);
 
-	return ret;
-
-fallback:
-	/* No EDID, fallback on the XGA standard modes */
-	ret = drm_add_modes_noedid(connector, 1920, 1200);
-
-	/* And prefer a mode pretty much anything can handle */
-	drm_set_preferred_mode(connector, 1024, 768);
-
 	return ret;
 }
 
@@ -92,21 +83,7 @@ tfp410_connector_detect(struct drm_connector *connector, bool force)
 {
 	struct tfp410 *dvi = drm_connector_to_tfp410(connector);
 
-	if (dvi->hpd) {
-		if (gpiod_get_value_cansleep(dvi->hpd))
-			return connector_status_connected;
-		else
-			return connector_status_disconnected;
-	}
-
-	if (dvi->ddc) {
-		if (drm_probe_ddc(dvi->ddc))
-			return connector_status_connected;
-		else
-			return connector_status_disconnected;
-	}
-
-	return connector_status_unknown;
+	return drm_bridge_detect(dvi->next_bridge);
 }
 
 static const struct drm_connector_funcs tfp410_con_funcs = {
@@ -118,12 +95,35 @@ static const struct drm_connector_funcs tfp410_con_funcs = {
 	.atomic_destroy_state	= drm_atomic_helper_connector_destroy_state,
 };
 
+static void tfp410_hpd_work_func(struct work_struct *work)
+{
+	struct tfp410 *dvi;
+
+	dvi = container_of(work, struct tfp410, hpd_work.work);
+
+	if (dvi->bridge.dev)
+		drm_helper_hpd_irq_event(dvi->bridge.dev);
+}
+
+static void tfp410_hpd_callback(void *arg, enum drm_connector_status status)
+{
+	struct tfp410 *dvi = arg;
+
+	mod_delayed_work(system_wq, &dvi->hpd_work,
+			 msecs_to_jiffies(HOTPLUG_DEBOUNCE_MS));
+}
+
 static int tfp410_attach(struct drm_bridge *bridge,
 			 enum drm_bridge_attach_flags flags)
 {
 	struct tfp410 *dvi = drm_bridge_to_tfp410(bridge);
 	int ret;
 
+	ret = drm_bridge_attach(bridge->encoder, dvi->next_bridge, bridge,
+				DRM_BRIDGE_ATTACH_NO_CONNECTOR);
+	if (ret < 0)
+		return ret;
+
 	if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) {
 		DRM_ERROR("Fix bridge driver to make connector optional!");
 		return -EINVAL;
@@ -134,17 +134,23 @@ static int tfp410_attach(struct drm_bridge *bridge,
 		return -ENODEV;
 	}
 
-	if (dvi->hpd_irq >= 0)
+	if (dvi->next_bridge->ops & DRM_BRIDGE_OP_DETECT)
 		dvi->connector.polled = DRM_CONNECTOR_POLL_HPD;
 	else
 		dvi->connector.polled = DRM_CONNECTOR_POLL_CONNECT | DRM_CONNECTOR_POLL_DISCONNECT;
 
+	if (dvi->next_bridge->ops & DRM_BRIDGE_OP_HPD) {
+		INIT_DELAYED_WORK(&dvi->hpd_work, tfp410_hpd_work_func);
+		drm_bridge_hpd_enable(dvi->next_bridge, tfp410_hpd_callback,
+				      dvi);
+	}
+
 	drm_connector_helper_add(&dvi->connector,
 				 &tfp410_con_helper_funcs);
 	ret = drm_connector_init_with_ddc(bridge->dev, &dvi->connector,
 					  &tfp410_con_funcs,
-					  dvi->connector_type,
-					  dvi->ddc);
+					  dvi->next_bridge->type,
+					  dvi->next_bridge->ddc);
 	if (ret) {
 		dev_err(dvi->dev, "drm_connector_init() failed: %d\n", ret);
 		return ret;
@@ -153,12 +159,21 @@ static int tfp410_attach(struct drm_bridge *bridge,
 	drm_display_info_set_bus_formats(&dvi->connector.display_info,
 					 &dvi->bus_format, 1);
 
-	drm_connector_attach_encoder(&dvi->connector,
-					  bridge->encoder);
+	drm_connector_attach_encoder(&dvi->connector, bridge->encoder);
 
 	return 0;
 }
 
+static void tfp410_detach(struct drm_bridge *bridge)
+{
+	struct tfp410 *dvi = drm_bridge_to_tfp410(bridge);
+
+	if (dvi->connector.dev && dvi->next_bridge->ops & DRM_BRIDGE_OP_HPD) {
+		drm_bridge_hpd_disable(dvi->next_bridge);
+		cancel_delayed_work_sync(&dvi->hpd_work);
+	}
+}
+
 static void tfp410_enable(struct drm_bridge *bridge)
 {
 	struct tfp410 *dvi = drm_bridge_to_tfp410(bridge);
@@ -187,31 +202,12 @@ static enum drm_mode_status tfp410_mode_valid(struct drm_bridge *bridge,
 
 static const struct drm_bridge_funcs tfp410_bridge_funcs = {
 	.attach		= tfp410_attach,
+	.detach		= tfp410_detach,
 	.enable		= tfp410_enable,
 	.disable	= tfp410_disable,
 	.mode_valid	= tfp410_mode_valid,
 };
 
-static void tfp410_hpd_work_func(struct work_struct *work)
-{
-	struct tfp410 *dvi;
-
-	dvi = container_of(work, struct tfp410, hpd_work.work);
-
-	if (dvi->bridge.dev)
-		drm_helper_hpd_irq_event(dvi->bridge.dev);
-}
-
-static irqreturn_t tfp410_hpd_irq_thread(int irq, void *arg)
-{
-	struct tfp410 *dvi = arg;
-
-	mod_delayed_work(system_wq, &dvi->hpd_work,
-			msecs_to_jiffies(HOTPLUG_DEBOUNCE_MS));
-
-	return IRQ_HANDLED;
-}
-
 static const struct drm_bridge_timings tfp410_default_timings = {
 	.input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE
 			 | DRM_BUS_FLAG_DE_HIGH,
@@ -289,51 +285,9 @@ static int tfp410_parse_timings(struct tfp410 *dvi, bool i2c)
 	return 0;
 }
 
-static int tfp410_get_connector_properties(struct tfp410 *dvi)
-{
-	struct device_node *connector_node, *ddc_phandle;
-	int ret = 0;
-
-	/* port@1 is the connector node */
-	connector_node = of_graph_get_remote_node(dvi->dev->of_node, 1, -1);
-	if (!connector_node)
-		return -ENODEV;
-
-	if (of_device_is_compatible(connector_node, "hdmi-connector"))
-		dvi->connector_type = DRM_MODE_CONNECTOR_HDMIA;
-	else
-		dvi->connector_type = DRM_MODE_CONNECTOR_DVID;
-
-	dvi->hpd = fwnode_gpiod_get_index(&connector_node->fwnode,
-					  "hpd", 0, GPIOD_IN, "hpd");
-	if (IS_ERR(dvi->hpd)) {
-		ret = PTR_ERR(dvi->hpd);
-		dvi->hpd = NULL;
-		if (ret == -ENOENT)
-			ret = 0;
-		else
-			goto fail;
-	}
-
-	ddc_phandle = of_parse_phandle(connector_node, "ddc-i2c-bus", 0);
-	if (!ddc_phandle)
-		goto fail;
-
-	dvi->ddc = of_get_i2c_adapter_by_node(ddc_phandle);
-	if (dvi->ddc)
-		dev_info(dvi->dev, "Connector's ddc i2c bus found\n");
-	else
-		ret = -EPROBE_DEFER;
-
-	of_node_put(ddc_phandle);
-
-fail:
-	of_node_put(connector_node);
-	return ret;
-}
-
 static int tfp410_init(struct device *dev, bool i2c)
 {
+	struct device_node *node;
 	struct tfp410 *dvi;
 	int ret;
 
@@ -345,21 +299,31 @@ static int tfp410_init(struct device *dev, bool i2c)
 	dvi = devm_kzalloc(dev, sizeof(*dvi), GFP_KERNEL);
 	if (!dvi)
 		return -ENOMEM;
+
+	dvi->dev = dev;
 	dev_set_drvdata(dev, dvi);
 
 	dvi->bridge.funcs = &tfp410_bridge_funcs;
 	dvi->bridge.of_node = dev->of_node;
 	dvi->bridge.timings = &dvi->timings;
-	dvi->dev = dev;
+	dvi->bridge.type = DRM_MODE_CONNECTOR_DVID;
 
 	ret = tfp410_parse_timings(dvi, i2c);
 	if (ret)
-		goto fail;
+		return ret;
 
-	ret = tfp410_get_connector_properties(dvi);
-	if (ret)
-		goto fail;
+	/* Get the next bridge, connected to port@1. */
+	node = of_graph_get_remote_node(dev->of_node, 1, -1);
+	if (!node)
+		return -ENODEV;
+
+	dvi->next_bridge = of_drm_find_bridge(node);
+	of_node_put(node);
+
+	if (!dvi->next_bridge)
+		return -EPROBE_DEFER;
 
+	/* Get the powerdown GPIO. */
 	dvi->powerdown = devm_gpiod_get_optional(dev, "powerdown",
 						 GPIOD_OUT_HIGH);
 	if (IS_ERR(dvi->powerdown)) {
@@ -367,48 +331,18 @@ static int tfp410_init(struct device *dev, bool i2c)
 		return PTR_ERR(dvi->powerdown);
 	}
 
-	if (dvi->hpd)
-		dvi->hpd_irq = gpiod_to_irq(dvi->hpd);
-	else
-		dvi->hpd_irq = -ENXIO;
-
-	if (dvi->hpd_irq >= 0) {
-		INIT_DELAYED_WORK(&dvi->hpd_work, tfp410_hpd_work_func);
-
-		ret = devm_request_threaded_irq(dev, dvi->hpd_irq,
-			NULL, tfp410_hpd_irq_thread, IRQF_TRIGGER_RISING |
-			IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
-			"hdmi-hpd", dvi);
-		if (ret) {
-			DRM_ERROR("failed to register hpd interrupt\n");
-			goto fail;
-		}
-	}
-
+	/*  Register the DRM bridge. */
 	drm_bridge_add(&dvi->bridge);
 
 	return 0;
-fail:
-	i2c_put_adapter(dvi->ddc);
-	if (dvi->hpd)
-		gpiod_put(dvi->hpd);
-	return ret;
 }
 
 static int tfp410_fini(struct device *dev)
 {
 	struct tfp410 *dvi = dev_get_drvdata(dev);
 
-	if (dvi->hpd_irq >= 0)
-		cancel_delayed_work_sync(&dvi->hpd_work);
-
 	drm_bridge_remove(&dvi->bridge);
 
-	if (dvi->ddc)
-		i2c_put_adapter(dvi->ddc);
-	if (dvi->hpd)
-		gpiod_put(dvi->hpd);
-
 	return 0;
 }