1 files changed, 215 insertions, 132 deletions

diff --git a/drivers/gpu/drm/bridge/parade-ps8640.c b/drivers/gpu/drm/bridge/parade-ps8640.c
index 3aaa90913bf8..818704bf5e86 100644
--- a/drivers/gpu/drm/bridge/parade-ps8640.c
+++ b/drivers/gpu/drm/bridge/parade-ps8640.c
@@ -9,10 +9,12 @@
 #include <linux/i2c.h>
 #include <linux/module.h>
 #include <linux/of_graph.h>
+#include <linux/pm_runtime.h>
 #include <linux/regmap.h>
 #include <linux/regulator/consumer.h>
 
 #include <drm/drm_bridge.h>
+#include <drm/drm_dp_aux_bus.h>
 #include <drm/drm_dp_helper.h>
 #include <drm/drm_mipi_dsi.h>
 #include <drm/drm_of.h>
@@ -100,7 +102,7 @@ struct ps8640 {
 	struct regulator_bulk_data supplies[2];
 	struct gpio_desc *gpio_reset;
 	struct gpio_desc *gpio_powerdown;
-	bool powered;
+	bool pre_enabled;
 };
 
 static const struct regmap_config ps8640_regmap_config[] = {
@@ -148,8 +150,46 @@ static inline struct ps8640 *aux_to_ps8640(struct drm_dp_aux *aux)
 	return container_of(aux, struct ps8640, aux);
 }
 
-static ssize_t ps8640_aux_transfer(struct drm_dp_aux *aux,
-				   struct drm_dp_aux_msg *msg)
+static bool ps8640_of_panel_on_aux_bus(struct device *dev)
+{
+	struct device_node *bus, *panel;
+
+	bus = of_get_child_by_name(dev->of_node, "aux-bus");
+	if (!bus)
+		return false;
+
+	panel = of_get_child_by_name(bus, "panel");
+	of_node_put(bus);
+	if (!panel)
+		return false;
+	of_node_put(panel);
+
+	return true;
+}
+
+static int ps8640_ensure_hpd(struct ps8640 *ps_bridge)
+{
+	struct regmap *map = ps_bridge->regmap[PAGE2_TOP_CNTL];
+	struct device *dev = &ps_bridge->page[PAGE2_TOP_CNTL]->dev;
+	int status;
+	int ret;
+
+	/*
+	 * Apparently something about the firmware in the chip signals that
+	 * HPD goes high by reporting GPIO9 as high (even though HPD isn't
+	 * actually connected to GPIO9).
+	 */
+	ret = regmap_read_poll_timeout(map, PAGE2_GPIO_H, status,
+				       status & PS_GPIO9, 20 * 1000, 200 * 1000);
+
+	if (ret < 0)
+		dev_warn(dev, "HPD didn't go high: %d\n", ret);
+
+	return ret;
+}
+
+static ssize_t ps8640_aux_transfer_msg(struct drm_dp_aux *aux,
+				       struct drm_dp_aux_msg *msg)
 {
 	struct ps8640 *ps_bridge = aux_to_ps8640(aux);
 	struct regmap *map = ps_bridge->regmap[PAGE0_DP_CNTL];
@@ -274,38 +314,49 @@ static ssize_t ps8640_aux_transfer(struct drm_dp_aux *aux,
 	return len;
 }
 
-static int ps8640_bridge_vdo_control(struct ps8640 *ps_bridge,
-				     const enum ps8640_vdo_control ctrl)
+static ssize_t ps8640_aux_transfer(struct drm_dp_aux *aux,
+				   struct drm_dp_aux_msg *msg)
+{
+	struct ps8640 *ps_bridge = aux_to_ps8640(aux);
+	struct device *dev = &ps_bridge->page[PAGE0_DP_CNTL]->dev;
+	int ret;
+
+	pm_runtime_get_sync(dev);
+	ret = ps8640_ensure_hpd(ps_bridge);
+	if (!ret)
+		ret = ps8640_aux_transfer_msg(aux, msg);
+	pm_runtime_mark_last_busy(dev);
+	pm_runtime_put_autosuspend(dev);
+
+	return ret;
+}
+
+static void ps8640_bridge_vdo_control(struct ps8640 *ps_bridge,
+				      const enum ps8640_vdo_control ctrl)
 {
 	struct regmap *map = ps_bridge->regmap[PAGE3_DSI_CNTL1];
+	struct device *dev = &ps_bridge->page[PAGE3_DSI_CNTL1]->dev;
 	u8 vdo_ctrl_buf[] = { VDO_CTL_ADD, ctrl };
 	int ret;
 
 	ret = regmap_bulk_write(map, PAGE3_SET_ADD,
 				vdo_ctrl_buf, sizeof(vdo_ctrl_buf));
 
-	if (ret < 0) {
-		DRM_ERROR("failed to %sable VDO: %d\n",
-			  ctrl == ENABLE ? "en" : "dis", ret);
-		return ret;
-	}
-
-	return 0;
+	if (ret < 0)
+		dev_err(dev, "failed to %sable VDO: %d\n",
+			ctrl == ENABLE ? "en" : "dis", ret);
 }
 
-static void ps8640_bridge_poweron(struct ps8640 *ps_bridge)
+static int __maybe_unused ps8640_resume(struct device *dev)
 {
-	struct regmap *map = ps_bridge->regmap[PAGE2_TOP_CNTL];
-	int ret, status;
-
-	if (ps_bridge->powered)
-		return;
+	struct ps8640 *ps_bridge = dev_get_drvdata(dev);
+	int ret;
 
 	ret = regulator_bulk_enable(ARRAY_SIZE(ps_bridge->supplies),
 				    ps_bridge->supplies);
 	if (ret < 0) {
-		DRM_ERROR("cannot enable regulators %d\n", ret);
-		return;
+		dev_err(dev, "cannot enable regulators %d\n", ret);
+		return ret;
 	}
 
 	gpiod_set_value(ps_bridge->gpio_powerdown, 0);
@@ -314,86 +365,78 @@ static void ps8640_bridge_poweron(struct ps8640 *ps_bridge)
 	gpiod_set_value(ps_bridge->gpio_reset, 0);
 
 	/*
-	 * Wait for the ps8640 embedded MCU to be ready
-	 * First wait 200ms and then check the MCU ready flag every 20ms
+	 * Mystery 200 ms delay for the "MCU to be ready". It's unclear if
+	 * this is truly necessary since the MCU will already signal that
+	 * things are "good to go" by signaling HPD on "gpio 9". See
+	 * ps8640_ensure_hpd(). For now we'll keep this mystery delay just in
+	 * case.
 	 */
 	msleep(200);
 
-	ret = regmap_read_poll_timeout(map, PAGE2_GPIO_H, status,
-				       status & PS_GPIO9, 20 * 1000, 200 * 1000);
-
-	if (ret < 0) {
-		DRM_ERROR("failed read PAGE2_GPIO_H: %d\n", ret);
-		goto err_regulators_disable;
-	}
-
-	msleep(50);
-
-	/*
-	 * The Manufacturer Command Set (MCS) is a device dependent interface
-	 * intended for factory programming of the display module default
-	 * parameters. Once the display module is configured, the MCS shall be
-	 * disabled by the manufacturer. Once disabled, all MCS commands are
-	 * ignored by the display interface.
-	 */
-
-	ret = regmap_update_bits(map, PAGE2_MCS_EN, MCS_EN, 0);
-	if (ret < 0) {
-		DRM_ERROR("failed write PAGE2_MCS_EN: %d\n", ret);
-		goto err_regulators_disable;
-	}
-
-	/* Switch access edp panel's edid through i2c */
-	ret = regmap_write(map, PAGE2_I2C_BYPASS, I2C_BYPASS_EN);
-	if (ret < 0) {
-		DRM_ERROR("failed write PAGE2_I2C_BYPASS: %d\n", ret);
-		goto err_regulators_disable;
-	}
-
-	ps_bridge->powered = true;
-
-	return;
-
-err_regulators_disable:
-	regulator_bulk_disable(ARRAY_SIZE(ps_bridge->supplies),
-			       ps_bridge->supplies);
+	return 0;
 }
 
-static void ps8640_bridge_poweroff(struct ps8640 *ps_bridge)
+static int __maybe_unused ps8640_suspend(struct device *dev)
 {
+	struct ps8640 *ps_bridge = dev_get_drvdata(dev);
 	int ret;
 
-	if (!ps_bridge->powered)
-		return;
-
 	gpiod_set_value(ps_bridge->gpio_reset, 1);
 	gpiod_set_value(ps_bridge->gpio_powerdown, 1);
 	ret = regulator_bulk_disable(ARRAY_SIZE(ps_bridge->supplies),
 				     ps_bridge->supplies);
 	if (ret < 0)
-		DRM_ERROR("cannot disable regulators %d\n", ret);
+		dev_err(dev, "cannot disable regulators %d\n", ret);
 
-	ps_bridge->powered = false;
+	return ret;
 }
 
+static const struct dev_pm_ops ps8640_pm_ops = {
+	SET_RUNTIME_PM_OPS(ps8640_suspend, ps8640_resume, NULL)
+	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+				pm_runtime_force_resume)
+};
+
 static void ps8640_pre_enable(struct drm_bridge *bridge)
 {
 	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
+	struct regmap *map = ps_bridge->regmap[PAGE2_TOP_CNTL];
+	struct device *dev = &ps_bridge->page[PAGE0_DP_CNTL]->dev;
 	int ret;
 
-	ps8640_bridge_poweron(ps_bridge);
+	pm_runtime_get_sync(dev);
+	ps8640_ensure_hpd(ps_bridge);
 
-	ret = ps8640_bridge_vdo_control(ps_bridge, ENABLE);
+	/*
+	 * The Manufacturer Command Set (MCS) is a device dependent interface
+	 * intended for factory programming of the display module default
+	 * parameters. Once the display module is configured, the MCS shall be
+	 * disabled by the manufacturer. Once disabled, all MCS commands are
+	 * ignored by the display interface.
+	 */
+
+	ret = regmap_update_bits(map, PAGE2_MCS_EN, MCS_EN, 0);
 	if (ret < 0)
-		ps8640_bridge_poweroff(ps_bridge);
+		dev_warn(dev, "failed write PAGE2_MCS_EN: %d\n", ret);
+
+	/* Switch access edp panel's edid through i2c */
+	ret = regmap_write(map, PAGE2_I2C_BYPASS, I2C_BYPASS_EN);
+	if (ret < 0)
+		dev_warn(dev, "failed write PAGE2_MCS_EN: %d\n", ret);
+
+	ps8640_bridge_vdo_control(ps_bridge, ENABLE);
+
+	ps_bridge->pre_enabled = true;
 }
 
 static void ps8640_post_disable(struct drm_bridge *bridge)
 {
 	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
 
+	ps_bridge->pre_enabled = false;
+
 	ps8640_bridge_vdo_control(ps_bridge, DISABLE);
-	ps8640_bridge_poweroff(ps_bridge);
+	pm_runtime_put_sync_suspend(&ps_bridge->page[PAGE0_DP_CNTL]->dev);
 }
 
 static int ps8640_bridge_attach(struct drm_bridge *bridge,
@@ -401,68 +444,21 @@ static int ps8640_bridge_attach(struct drm_bridge *bridge,
 {
 	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
 	struct device *dev = &ps_bridge->page[0]->dev;
-	struct device_node *in_ep, *dsi_node;
-	struct mipi_dsi_device *dsi;
-	struct mipi_dsi_host *host;
 	int ret;
-	const struct mipi_dsi_device_info info = { .type = "ps8640",
-						   .channel = 0,
-						   .node = NULL,
-						 };
 
 	if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR))
 		return -EINVAL;
 
-	/* port@0 is ps8640 dsi input port */
-	in_ep = of_graph_get_endpoint_by_regs(dev->of_node, 0, -1);
-	if (!in_ep)
-		return -ENODEV;
-
-	dsi_node = of_graph_get_remote_port_parent(in_ep);
-	of_node_put(in_ep);
-	if (!dsi_node)
-		return -ENODEV;
-
-	host = of_find_mipi_dsi_host_by_node(dsi_node);
-	of_node_put(dsi_node);
-	if (!host)
-		return -ENODEV;
-
-	dsi = mipi_dsi_device_register_full(host, &info);
-	if (IS_ERR(dsi)) {
-		dev_err(dev, "failed to create dsi device\n");
-		ret = PTR_ERR(dsi);
-		return ret;
-	}
-
-	ps_bridge->dsi = dsi;
-
-	dsi->host = host;
-	dsi->mode_flags = MIPI_DSI_MODE_VIDEO |
-			  MIPI_DSI_MODE_VIDEO_SYNC_PULSE;
-	dsi->format = MIPI_DSI_FMT_RGB888;
-	dsi->lanes = NUM_MIPI_LANES;
-	ret = mipi_dsi_attach(dsi);
-	if (ret) {
-		dev_err(dev, "failed to attach dsi device: %d\n", ret);
-		goto err_dsi_attach;
-	}
-
+	ps_bridge->aux.drm_dev = bridge->dev;
 	ret = drm_dp_aux_register(&ps_bridge->aux);
 	if (ret) {
 		dev_err(dev, "failed to register DP AUX channel: %d\n", ret);
-		goto err_aux_register;
+		return ret;
 	}
 
 	/* Attach the panel-bridge to the dsi bridge */
 	return drm_bridge_attach(bridge->encoder, ps_bridge->panel_bridge,
 				 &ps_bridge->bridge, flags);
-
-err_aux_register:
-	mipi_dsi_detach(dsi);
-err_dsi_attach:
-	mipi_dsi_device_unregister(dsi);
-	return ret;
 }
 
 static void ps8640_bridge_detach(struct drm_bridge *bridge)
@@ -474,7 +470,7 @@ static struct edid *ps8640_bridge_get_edid(struct drm_bridge *bridge,
 					   struct drm_connector *connector)
 {
 	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
-	bool poweroff = !ps_bridge->powered;
+	bool poweroff = !ps_bridge->pre_enabled;
 	struct edid *edid;
 
 	/*
@@ -504,6 +500,12 @@ static struct edid *ps8640_bridge_get_edid(struct drm_bridge *bridge,
 	return edid;
 }
 
+static void ps8640_runtime_disable(void *data)
+{
+	pm_runtime_dont_use_autosuspend(data);
+	pm_runtime_disable(data);
+}
+
 static const struct drm_bridge_funcs ps8640_bridge_funcs = {
 	.attach = ps8640_bridge_attach,
 	.detach = ps8640_bridge_detach,
@@ -512,6 +514,53 @@ static const struct drm_bridge_funcs ps8640_bridge_funcs = {
 	.pre_enable = ps8640_pre_enable,
 };
 
+static int ps8640_bridge_host_attach(struct device *dev, struct ps8640 *ps_bridge)
+{
+	struct device_node *in_ep, *dsi_node;
+	struct mipi_dsi_device *dsi;
+	struct mipi_dsi_host *host;
+	int ret;
+	const struct mipi_dsi_device_info info = { .type = "ps8640",
+						   .channel = 0,
+						   .node = NULL,
+						 };
+
+	/* port@0 is ps8640 dsi input port */
+	in_ep = of_graph_get_endpoint_by_regs(dev->of_node, 0, -1);
+	if (!in_ep)
+		return -ENODEV;
+
+	dsi_node = of_graph_get_remote_port_parent(in_ep);
+	of_node_put(in_ep);
+	if (!dsi_node)
+		return -ENODEV;
+
+	host = of_find_mipi_dsi_host_by_node(dsi_node);
+	of_node_put(dsi_node);
+	if (!host)
+		return -EPROBE_DEFER;
+
+	dsi = devm_mipi_dsi_device_register_full(dev, host, &info);
+	if (IS_ERR(dsi)) {
+		dev_err(dev, "failed to create dsi device\n");
+		return PTR_ERR(dsi);
+	}
+
+	ps_bridge->dsi = dsi;
+
+	dsi->host = host;
+	dsi->mode_flags = MIPI_DSI_MODE_VIDEO |
+			  MIPI_DSI_MODE_VIDEO_SYNC_PULSE;
+	dsi->format = MIPI_DSI_FMT_RGB888;
+	dsi->lanes = NUM_MIPI_LANES;
+
+	ret = devm_mipi_dsi_attach(dev, dsi);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
 static int ps8640_probe(struct i2c_client *client)
 {
 	struct device *dev = &client->dev;
@@ -525,17 +574,6 @@ static int ps8640_probe(struct i2c_client *client)
 	if (!ps_bridge)
 		return -ENOMEM;
 
-	/* port@1 is ps8640 output port */
-	ret = drm_of_find_panel_or_bridge(np, 1, 0, &panel, NULL);
-	if (ret < 0)
-		return ret;
-	if (!panel)
-		return -ENODEV;
-
-	ps_bridge->panel_bridge = devm_drm_panel_bridge_add(dev, panel);
-	if (IS_ERR(ps_bridge->panel_bridge))
-		return PTR_ERR(ps_bridge->panel_bridge);
-
 	ps_bridge->supplies[0].supply = "vdd33";
 	ps_bridge->supplies[1].supply = "vdd12";
 	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ps_bridge->supplies),
@@ -558,9 +596,16 @@ static int ps8640_probe(struct i2c_client *client)
 
 	ps_bridge->bridge.funcs = &ps8640_bridge_funcs;
 	ps_bridge->bridge.of_node = dev->of_node;
-	ps_bridge->bridge.ops = DRM_BRIDGE_OP_EDID;
 	ps_bridge->bridge.type = DRM_MODE_CONNECTOR_eDP;
 
+	/*
+	 * In the device tree, if panel is listed under aux-bus of the bridge
+	 * node, panel driver should be able to retrieve EDID by itself using
+	 * aux-bus. So let's not set DRM_BRIDGE_OP_EDID here.
+	 */
+	if (!ps8640_of_panel_on_aux_bus(&client->dev))
+		ps_bridge->bridge.ops = DRM_BRIDGE_OP_EDID;
+
 	ps_bridge->page[PAGE0_DP_CNTL] = client;
 
 	ps_bridge->regmap[PAGE0_DP_CNTL] = devm_regmap_init_i2c(client, ps8640_regmap_config);
@@ -587,9 +632,46 @@ static int ps8640_probe(struct i2c_client *client)
 	ps_bridge->aux.transfer = ps8640_aux_transfer;
 	drm_dp_aux_init(&ps_bridge->aux);
 
+	pm_runtime_enable(dev);
+	/*
+	 * Powering on ps8640 takes ~300ms. To avoid wasting time on power
+	 * cycling ps8640 too often, set autosuspend_delay to 1000ms to ensure
+	 * the bridge wouldn't suspend in between each _aux_transfer_msg() call
+	 * during EDID read (~20ms in my experiment) and in between the last
+	 * _aux_transfer_msg() call during EDID read and the _pre_enable() call
+	 * (~100ms in my experiment).
+	 */
+	pm_runtime_set_autosuspend_delay(dev, 1000);
+	pm_runtime_use_autosuspend(dev);
+	pm_suspend_ignore_children(dev, true);
+	ret = devm_add_action_or_reset(dev, ps8640_runtime_disable, dev);
+	if (ret)
+		return ret;
+
+	devm_of_dp_aux_populate_ep_devices(&ps_bridge->aux);
+
+	/* port@1 is ps8640 output port */
+	ret = drm_of_find_panel_or_bridge(np, 1, 0, &panel, NULL);
+	if (ret < 0)
+		return ret;
+	if (!panel)
+		return -ENODEV;
+
+	ps_bridge->panel_bridge = devm_drm_panel_bridge_add(dev, panel);
+	if (IS_ERR(ps_bridge->panel_bridge))
+		return PTR_ERR(ps_bridge->panel_bridge);
+
 	drm_bridge_add(&ps_bridge->bridge);
 
+	ret = ps8640_bridge_host_attach(dev, ps_bridge);
+	if (ret)
+		goto err_bridge_remove;
+
 	return 0;
+
+err_bridge_remove:
+	drm_bridge_remove(&ps_bridge->bridge);
+	return ret;
 }
 
 static int ps8640_remove(struct i2c_client *client)
@@ -613,6 +695,7 @@ static struct i2c_driver ps8640_driver = {
 	.driver = {
 		.name = "ps8640",
 		.of_match_table = ps8640_match,
+		.pm = &ps8640_pm_ops,
 	},
 };
 module_i2c_driver(ps8640_driver);