[PATCH v4 6/7] drm/bridge: anx7625: Register Type-C mode switches

[Prashant Malani]

When the DT node has "switches" available, register a Type-C mode-switch
for each listed "switch". This allows the driver to receive state
information about what operating mode a Type-C port and its connected
peripherals are in, as well as status information (like VDOs) related to
that state.

The callback function is currently a stub, but subsequent patches will
implement the required functionality.

Reviewed-by: Nícolas F. R. A. Prado <nfraprado at collabora.com>
Tested-by: Nícolas F. R. A. Prado <nfraprado at collabora.com>
Signed-off-by: Prashant Malani <pmalani at chromium.org>
---

Changes since v3:
- No changes.

Changes since v2:
- Updated dev_info() to dev_warn() print, but added a check to ensure it
  only triggers on non -ENODEV errors.
- Made conflict resolutions resulting from changes introduced in
  Patch v3 5/7 (add ret variable here instead of in Patch v3 5/7).
- Added Reviewed-by and Tested-by tags.

Changes since v1:
- No changes.

 drivers/gpu/drm/bridge/analogix/anx7625.c | 82 +++++++++++++++++++++--
 drivers/gpu/drm/bridge/analogix/anx7625.h |  6 ++
 2 files changed, 84 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.c b/drivers/gpu/drm/bridge/analogix/anx7625.c
index e3d4c2738b8c..bd21f159b973 100644
--- a/drivers/gpu/drm/bridge/analogix/anx7625.c
+++ b/drivers/gpu/drm/bridge/analogix/anx7625.c
@@ -15,6 +15,7 @@
 #include <linux/regulator/consumer.h>
 #include <linux/slab.h>
 #include <linux/types.h>
+#include <linux/usb/typec_mux.h>
 #include <linux/workqueue.h>
 
 #include <linux/of_gpio.h>
@@ -2581,10 +2582,61 @@ static void anx7625_runtime_disable(void *data)
 	pm_runtime_disable(data);
 }
 
+static int anx7625_typec_mux_set(struct typec_mux_dev *mux,
+				 struct typec_mux_state *state)
+{
+	return 0;
+}
+
+static int anx7625_register_mode_switch(struct device *dev, struct device_node *node,
+					struct anx7625_data *ctx)
+{
+	struct anx7625_port_data *port_data;
+	struct typec_mux_desc mux_desc = {};
+	char name[32];
+	u32 port_num;
+	int ret;
+
+	ret = of_property_read_u32(node, "reg", &port_num);
+	if (ret)
+		return ret;
+
+	if (port_num >= ctx->num_typec_switches) {
+		dev_err(dev, "Invalid port number specified: %d\n", port_num);
+		return -EINVAL;
+	}
+
+	port_data = &ctx->typec_ports[port_num];
+	port_data->ctx = ctx;
+	mux_desc.fwnode = &node->fwnode;
+	mux_desc.drvdata = port_data;
+	snprintf(name, sizeof(name), "%s-%u", node->name, port_num);
+	mux_desc.name = name;
+	mux_desc.set = anx7625_typec_mux_set;
+
+	port_data->typec_mux = typec_mux_register(dev, &mux_desc);
+	if (IS_ERR(port_data->typec_mux)) {
+		ret = PTR_ERR(port_data->typec_mux);
+		dev_err(dev, "Mode switch register for port %d failed: %d", port_num, ret);
+	}
+
+	return ret;
+}
+
+static void anx7625_unregister_typec_switches(struct anx7625_data *ctx)
+{
+	int i;
+
+	for (i = 0; i < ctx->num_typec_switches; i++)
+		typec_mux_unregister(ctx->typec_ports[i].typec_mux);
+}
+
 static int anx7625_register_typec_switches(struct device *device, struct anx7625_data *ctx)
 {
-	struct device_node *of = of_get_child_by_name(device->of_node, "switches");
+	struct device_node *of, *sw;
+	int ret = 0;
 
+	of = of_get_child_by_name(device->of_node, "switches");
 	if (!of)
 		return -ENODEV;
 
@@ -2592,7 +2644,27 @@ static int anx7625_register_typec_switches(struct device *device, struct anx7625
 	if (ctx->num_typec_switches <= 0)
 		return -ENODEV;
 
-	return 0;
+	ctx->typec_ports = devm_kzalloc(device,
+					ctx->num_typec_switches * sizeof(struct anx7625_port_data),
+					GFP_KERNEL);
+	if (!ctx->typec_ports)
+		return -ENOMEM;
+
+	/* Register switches for each connector. */
+	for_each_available_child_of_node(of, sw) {
+		if (!of_property_read_bool(sw, "mode-switch"))
+			continue;
+		ret = anx7625_register_mode_switch(device, sw, ctx);
+		if (ret) {
+			dev_err(device, "Failed to register mode switch: %d\n", ret);
+			break;
+		}
+	}
+
+	if (ret)
+		anx7625_unregister_typec_switches(ctx);
+
+	return ret;
 }
 
 static int anx7625_i2c_probe(struct i2c_client *client,
@@ -2701,8 +2773,8 @@ static int anx7625_i2c_probe(struct i2c_client *client,
 		queue_work(platform->workqueue, &platform->work);
 
 	ret = anx7625_register_typec_switches(dev, platform);
-	if (ret)
-		dev_dbg(dev, "Didn't register Type C switches, err: %d\n", ret);
+	if (ret && ret != -ENODEV)
+		dev_warn(dev, "Didn't register Type C switches, err: %d\n", ret);
 
 	platform->bridge.funcs = &anx7625_bridge_funcs;
 	platform->bridge.of_node = client->dev.of_node;
@@ -2757,6 +2829,8 @@ static int anx7625_i2c_remove(struct i2c_client *client)
 
 	drm_bridge_remove(&platform->bridge);
 
+	anx7625_unregister_typec_switches(platform);
+
 	if (platform->pdata.intp_irq)
 		destroy_workqueue(platform->workqueue);
 
diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.h b/drivers/gpu/drm/bridge/analogix/anx7625.h
index d5cbca708842..76cfc64f7574 100644
--- a/drivers/gpu/drm/bridge/analogix/anx7625.h
+++ b/drivers/gpu/drm/bridge/analogix/anx7625.h
@@ -443,6 +443,11 @@ struct anx7625_i2c_client {
 	struct i2c_client *tcpc_client;
 };
 
+struct anx7625_port_data {
+	struct typec_mux_dev *typec_mux;
+	struct anx7625_data *ctx;
+};
+
 struct anx7625_data {
 	struct anx7625_platform_data pdata;
 	struct platform_device *audio_pdev;
@@ -474,6 +479,7 @@ struct anx7625_data {
 	struct mipi_dsi_device *dsi;
 	struct drm_dp_aux aux;
 	int num_typec_switches;
+	struct anx7625_port_data *typec_ports;
 };
 
 #endif  /* __ANX7625_H__ */
-- 
2.36.1.476.g0c4daa206d-goog