Re: [PATCH v11 3/9] drm/display: Add Type-C switch helpers

From: Andi Shyti
Date: Tue Feb 07 2023 - 16:26:26 EST


Hi Pin-yen,

[...]

> +static int drm_dp_register_mode_switch(struct device *dev,
> + struct fwnode_handle *fwnode,
> + struct drm_dp_typec_switch_desc *switch_desc,
> + void *data, typec_mux_set_fn_t mux_set)
> +{
> + struct drm_dp_typec_port_data *port_data;
> + struct typec_mux_desc mux_desc = {};
> + char name[32];
> + u32 port_num;
> + int ret;
> +
> + ret = fwnode_property_read_u32(fwnode, "reg", &port_num);
> + if (ret) {
> + dev_err(dev, "Failed to read reg property: %d\n", ret);
> + return ret;
> + }
> +
> + port_data = &switch_desc->typec_ports[port_num];
> + port_data->data = data;
> + port_data->port_num = port_num;
> + port_data->fwnode = fwnode;
> + mux_desc.fwnode = fwnode;
> + mux_desc.drvdata = port_data;
> + snprintf(name, sizeof(name), "%pfwP-%u", fwnode, port_num);
> + mux_desc.name = name;
> + mux_desc.set = 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\n",
> + port_num, ret);
> +
> + return ret;

you don't need this return here...

> + }
> +
> + return 0;

Just "return ret;" here.

> +}
> +
> +/**
> + * drm_dp_register_typec_switches() - register Type-C switches
> + * @dev: Device that registers Type-C switches
> + * @port: Device node for the switch
> + * @switch_desc: A Type-C switch descriptor
> + * @data: Private data for the switches
> + * @mux_set: Callback function for typec_mux_set
> + *
> + * This function registers USB Type-C switches for DP bridges that can switch
> + * the output signal between their output pins.
> + *
> + * Currently only mode switches are implemented, and the function assumes the
> + * given @port device node has endpoints with "mode-switch" property.
> + * The port number is determined by the "reg" property of the endpoint.
> + */
> +int drm_dp_register_typec_switches(struct device *dev, struct fwnode_handle *port,
> + struct drm_dp_typec_switch_desc *switch_desc,
> + void *data, typec_mux_set_fn_t mux_set)
> +{
> + struct fwnode_handle *sw;
> + int ret;
> +
> + fwnode_for_each_child_node(port, sw) {
> + if (fwnode_property_present(sw, "mode-switch"))
> + switch_desc->num_typec_switches++;
> + }

no need for brackets here

> +
> + if (!switch_desc->num_typec_switches) {
> + dev_dbg(dev, "No Type-C switches node found\n");

dev_warn()?

> + return 0;
> + }
> +
> + switch_desc->typec_ports = devm_kcalloc(
> + dev, switch_desc->num_typec_switches,
> + sizeof(struct drm_dp_typec_port_data), GFP_KERNEL);
> +
> + if (!switch_desc->typec_ports)
> + return -ENOMEM;
> +
> + /* Register switches for each connector. */
> + fwnode_for_each_child_node(port, sw) {
> + if (!fwnode_property_present(sw, "mode-switch"))
> + continue;
> + ret = drm_dp_register_mode_switch(dev, sw, switch_desc, data, mux_set);
> + if (ret)
> + goto err_unregister_typec_switches;
> + }
> +
> + return 0;
> +
> +err_unregister_typec_switches:
> + fwnode_handle_put(sw);
> + drm_dp_unregister_typec_switches(switch_desc);
> + dev_err(dev, "Failed to register mode switch: %d\n", ret);

there is a bit of dmesg spamming. Please choose where you want to
print the error, either in this function or in
drm_dp_register_mode_switch().

Andi

> + return ret;
> +}
> +EXPORT_SYMBOL(drm_dp_register_typec_switches);

[...]