drivers/platform/chrome/cros_typec_switch.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright 2022 Google LLC
  *
  * This driver provides the ability to configure Type-C muxes and retimers which are controlled by
  * the ChromeOS EC.
  */

 #include <linux/acpi.h>
 #include <linux/delay.h>
 #include <linux/jiffies.h>
 #include <linux/module.h>
 #include <linux/platform_data/cros_ec_commands.h>
 #include <linux/platform_data/cros_ec_proto.h>
 #include <linux/platform_device.h>
 #include <linux/usb/typec_altmode.h>
 #include <linux/usb/typec_dp.h>
 #include <linux/usb/typec_mux.h>
 #include <linux/usb/typec_retimer.h>

 /* Handles and other relevant data required for each port's switches. */
 struct cros_typec_port {
 	int port_num;
 	struct typec_mux_dev *mode_switch;
 	struct typec_retimer *retimer;
 	struct cros_typec_switch_data *sdata;
 };

 /* Driver-specific data. */
 struct cros_typec_switch_data {
 	struct device *dev;
 	struct cros_ec_device *ec;
 	struct cros_typec_port *ports[EC_USB_PD_MAX_PORTS];
 };

 static int cros_typec_cmd_mux_set(struct cros_typec_switch_data *sdata, int port_num, u8 index,
 				  u8 state)
 {
 	struct ec_params_typec_control req = {
 		.port = port_num,
 		.command = TYPEC_CONTROL_COMMAND_USB_MUX_SET,
 		.mux_params = {
 			.mux_index = index,
 			.mux_flags = state,
 		},
 	};

 	return cros_ec_cmd(sdata->ec, 0, EC_CMD_TYPEC_CONTROL, &req, sizeof(req), NULL, 0);
 }

 static int cros_typec_get_mux_state(unsigned long mode, struct typec_altmode *alt)
 {
 	int ret = -EOPNOTSUPP;
 	u8 pin_assign;

 	if (mode == TYPEC_STATE_SAFE) {
 		ret = USB_PD_MUX_SAFE_MODE;
 	} else if (mode == TYPEC_STATE_USB) {
 		ret = USB_PD_MUX_USB_ENABLED;
 	} else if (alt && alt->svid == USB_TYPEC_DP_SID) {
 		ret = USB_PD_MUX_DP_ENABLED;
 		pin_assign = mode - TYPEC_STATE_MODAL;
 		if (pin_assign & DP_PIN_ASSIGN_D)
 			ret |= USB_PD_MUX_USB_ENABLED;
 	}

 	return ret;
 }

 static int cros_typec_send_clear_event(struct cros_typec_switch_data *sdata, int port_num,
 				       u32 events_mask)
 {
 	struct ec_params_typec_control req = {
 		.port = port_num,
 		.command = TYPEC_CONTROL_COMMAND_CLEAR_EVENTS,
 		.clear_events_mask = events_mask,
 	};

 	return cros_ec_cmd(sdata->ec, 0, EC_CMD_TYPEC_CONTROL, &req, sizeof(req), NULL, 0);
 }

 static bool cros_typec_check_event(struct cros_typec_switch_data *sdata, int port_num, u32 mask)
 {
 	struct ec_response_typec_status resp;
 	struct ec_params_typec_status req = {
 		.port = port_num,
 	};
 	int ret;

 	ret = cros_ec_cmd(sdata->ec, 0, EC_CMD_TYPEC_STATUS, &req, sizeof(req),
 			  &resp, sizeof(resp));
 	if (ret < 0) {
 		dev_warn(sdata->dev, "EC_CMD_TYPEC_STATUS failed for port: %d\n", port_num);
 		return false;
 	}

 	if (resp.events & mask)
 		return true;

 	return false;
 }

 /*
  * The ChromeOS EC treats both mode-switches and retimers as "muxes" for the purposes of the
  * host command API. This common function configures and verifies the retimer/mode-switch
  * according to the provided setting.
  */
 static int cros_typec_configure_mux(struct cros_typec_switch_data *sdata, int port_num, int index,
 				    unsigned long mode, struct typec_altmode *alt)
 {
 	unsigned long end;
 	u32 event_mask;
 	u8 mux_state;
 	int ret;

 	ret = cros_typec_get_mux_state(mode, alt);
 	if (ret < 0)
 		return ret;
 	mux_state = (u8)ret;

 	/* Clear any old mux set done event. */
 	if (index == 0)
 		event_mask = PD_STATUS_EVENT_MUX_0_SET_DONE;
 	else
 		event_mask = PD_STATUS_EVENT_MUX_1_SET_DONE;

 	ret = cros_typec_send_clear_event(sdata, port_num, event_mask);
 	if (ret < 0)
 		return ret;

 	/* Send the set command. */
 	ret = cros_typec_cmd_mux_set(sdata, port_num, index, mux_state);
 	if (ret < 0)
 		return ret;

 	/* Check for the mux set done event. */
 	end = jiffies + msecs_to_jiffies(1000);
 	do {
 		if (cros_typec_check_event(sdata, port_num, event_mask))
 			return 0;

 		usleep_range(500, 1000);
 	} while (time_before(jiffies, end));

 	dev_err(sdata->dev, "Timed out waiting for mux set done on index: %d, state: %d\n",
 		index, mux_state);

 	return -ETIMEDOUT;
 }

 static int cros_typec_mode_switch_set(struct typec_mux_dev *mode_switch,
 				      struct typec_mux_state *state)
 {
 	struct cros_typec_port *port = typec_mux_get_drvdata(mode_switch);

 	/* Mode switches have index 0. */
 	return cros_typec_configure_mux(port->sdata, port->port_num, 0, state->mode, state->alt);
 }

 static int cros_typec_retimer_set(struct typec_retimer *retimer, struct typec_retimer_state *state)
 {
 	struct cros_typec_port *port = typec_retimer_get_drvdata(retimer);

 	/* Retimers have index 1. */
 	return cros_typec_configure_mux(port->sdata, port->port_num, 1, state->mode, state->alt);
 }

 static void cros_typec_unregister_switches(struct cros_typec_switch_data *sdata)
 {
 	int i;

 	for (i = 0; i < EC_USB_PD_MAX_PORTS; i++) {
 		if (!sdata->ports[i])
 			continue;
 		typec_retimer_unregister(sdata->ports[i]->retimer);
 		typec_mux_unregister(sdata->ports[i]->mode_switch);
 	}
 }

 static int cros_typec_register_mode_switch(struct cros_typec_port *port,
 					   struct fwnode_handle *fwnode)
 {
 	struct typec_mux_desc mode_switch_desc = {
 		.fwnode = fwnode,
 		.drvdata = port,
 		.name = fwnode_get_name(fwnode),
 		.set = cros_typec_mode_switch_set,
 	};

 	port->mode_switch = typec_mux_register(port->sdata->dev, &mode_switch_desc);

 	return PTR_ERR_OR_ZERO(port->mode_switch);
 }

 static int cros_typec_register_retimer(struct cros_typec_port *port, struct fwnode_handle *fwnode)
 {
 	struct typec_retimer_desc retimer_desc = {
 		.fwnode = fwnode,
 		.drvdata = port,
 		.name = fwnode_get_name(fwnode),
 		.set = cros_typec_retimer_set,
 	};

 	port->retimer = typec_retimer_register(port->sdata->dev, &retimer_desc);

 	return PTR_ERR_OR_ZERO(port->retimer);
 }

 static int cros_typec_register_switches(struct cros_typec_switch_data *sdata)
 {
 	struct cros_typec_port *port;
 	struct device *dev = sdata->dev;
 	struct fwnode_handle *fwnode;
 	struct acpi_device *adev;
 	unsigned long long index;
 	int nports, ret;

 	nports = device_get_child_node_count(dev);
 	if (nports == 0) {
 		dev_err(dev, "No switch devices found.\n");
 		return -ENODEV;
 	}

 	device_for_each_child_node(dev, fwnode) {
 		port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL);
 		if (!port) {
 			ret = -ENOMEM;
 			goto err_switch;
 		}

 		adev = to_acpi_device_node(fwnode);
 		if (!adev) {
 			dev_err(fwnode->dev, "Couldn't get ACPI device handle\n");
 			ret = -ENODEV;
 			goto err_switch;
 		}

 		ret = acpi_evaluate_integer(adev->handle, "_ADR", NULL, &index);
 		if (ACPI_FAILURE(ret)) {
 			dev_err(fwnode->dev, "_ADR wasn't evaluated\n");
 			ret = -ENODATA;
 			goto err_switch;
 		}

 		if (index >= EC_USB_PD_MAX_PORTS) {
 			dev_err(fwnode->dev, "Invalid port index number: %llu\n", index);
 			ret = -EINVAL;
 			goto err_switch;
 		}
 		port->sdata = sdata;
 		port->port_num = index;
 		sdata->ports[index] = port;

 		if (fwnode_property_present(fwnode, "retimer-switch")) {
 			ret = cros_typec_register_retimer(port, fwnode);
 			if (ret) {
 				dev_err(dev, "Retimer switch register failed\n");
 				goto err_switch;
 			}

 			dev_dbg(dev, "Retimer switch registered for index %llu\n", index);
 		}

 		if (!fwnode_property_present(fwnode, "mode-switch"))
 			continue;

 		ret = cros_typec_register_mode_switch(port, fwnode);
 		if (ret) {
 			dev_err(dev, "Mode switch register failed\n");
 			goto err_switch;
 		}

 		dev_dbg(dev, "Mode switch registered for index %llu\n", index);
 	}

 	return 0;
 err_switch:
 	fwnode_handle_put(fwnode);
 	cros_typec_unregister_switches(sdata);
 	return ret;
 }

 static int cros_typec_switch_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct cros_typec_switch_data *sdata;

 	sdata = devm_kzalloc(dev, sizeof(*sdata), GFP_KERNEL);
 	if (!sdata)
 		return -ENOMEM;

 	sdata->dev = dev;
 	sdata->ec = dev_get_drvdata(pdev->dev.parent);

 	platform_set_drvdata(pdev, sdata);

 	return cros_typec_register_switches(sdata);
 }

 static void cros_typec_switch_remove(struct platform_device *pdev)
 {
 	struct cros_typec_switch_data *sdata = platform_get_drvdata(pdev);

 	cros_typec_unregister_switches(sdata);
 }

 #ifdef CONFIG_ACPI
 static const struct acpi_device_id cros_typec_switch_acpi_id[] = {
 	{ "GOOG001A", 0 },
 	{}
 };
 MODULE_DEVICE_TABLE(acpi, cros_typec_switch_acpi_id);
 #endif

 static struct platform_driver cros_typec_switch_driver = {
 	.driver	= {
 		.name = "cros-typec-switch",
 		.acpi_match_table = ACPI_PTR(cros_typec_switch_acpi_id),
 	},
 	.probe = cros_typec_switch_probe,
 	.remove_new = cros_typec_switch_remove,
 };

 module_platform_driver(cros_typec_switch_driver);

 MODULE_AUTHOR("Prashant Malani <pmalani@chromium.org>");
 MODULE_DESCRIPTION("ChromeOS EC Type-C Switch control");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Copyright 2022 Google LLC
	*
	* This driver provides the ability to configure Type-C muxes and retimers which are controlled by
	* the ChromeOS EC.
	*/

	#include <linux/acpi.h>
	#include <linux/delay.h>
	#include <linux/jiffies.h>
	#include <linux/module.h>
	#include <linux/platform_data/cros_ec_commands.h>
	#include <linux/platform_data/cros_ec_proto.h>
	#include <linux/platform_device.h>
	#include <linux/usb/typec_altmode.h>
	#include <linux/usb/typec_dp.h>
	#include <linux/usb/typec_mux.h>
	#include <linux/usb/typec_retimer.h>

	/* Handles and other relevant data required for each port's switches. */
	struct cros_typec_port {
	int port_num;
	struct typec_mux_dev *mode_switch;
	struct typec_retimer *retimer;
	struct cros_typec_switch_data *sdata;
	};

	/* Driver-specific data. */
	struct cros_typec_switch_data {
	struct device *dev;
	struct cros_ec_device *ec;
	struct cros_typec_port *ports[EC_USB_PD_MAX_PORTS];
	};

	static int cros_typec_cmd_mux_set(struct cros_typec_switch_data *sdata, int port_num, u8 index,
	u8 state)
	{
	struct ec_params_typec_control req = {
	.port = port_num,
	.command = TYPEC_CONTROL_COMMAND_USB_MUX_SET,
	.mux_params = {
	.mux_index = index,
	.mux_flags = state,
	},
	};

	return cros_ec_cmd(sdata->ec, 0, EC_CMD_TYPEC_CONTROL, &req, sizeof(req), NULL, 0);
	}

	static int cros_typec_get_mux_state(unsigned long mode, struct typec_altmode *alt)
	{
	int ret = -EOPNOTSUPP;
	u8 pin_assign;

	if (mode == TYPEC_STATE_SAFE) {
	ret = USB_PD_MUX_SAFE_MODE;
	} else if (mode == TYPEC_STATE_USB) {
	ret = USB_PD_MUX_USB_ENABLED;
	} else if (alt && alt->svid == USB_TYPEC_DP_SID) {
	ret = USB_PD_MUX_DP_ENABLED;
	pin_assign = mode - TYPEC_STATE_MODAL;
	if (pin_assign & DP_PIN_ASSIGN_D)
	ret \|= USB_PD_MUX_USB_ENABLED;
	}

	return ret;
	}

	static int cros_typec_send_clear_event(struct cros_typec_switch_data *sdata, int port_num,
	u32 events_mask)
	{
	struct ec_params_typec_control req = {
	.port = port_num,
	.command = TYPEC_CONTROL_COMMAND_CLEAR_EVENTS,
	.clear_events_mask = events_mask,
	};

	return cros_ec_cmd(sdata->ec, 0, EC_CMD_TYPEC_CONTROL, &req, sizeof(req), NULL, 0);
	}

	static bool cros_typec_check_event(struct cros_typec_switch_data *sdata, int port_num, u32 mask)
	{
	struct ec_response_typec_status resp;
	struct ec_params_typec_status req = {
	.port = port_num,
	};
	int ret;

	ret = cros_ec_cmd(sdata->ec, 0, EC_CMD_TYPEC_STATUS, &req, sizeof(req),
	&resp, sizeof(resp));
	if (ret < 0) {
	dev_warn(sdata->dev, "EC_CMD_TYPEC_STATUS failed for port: %d\n", port_num);
	return false;
	}

	if (resp.events & mask)
	return true;

	return false;
	}

	/*
	* The ChromeOS EC treats both mode-switches and retimers as "muxes" for the purposes of the
	* host command API. This common function configures and verifies the retimer/mode-switch
	* according to the provided setting.
	*/
	static int cros_typec_configure_mux(struct cros_typec_switch_data *sdata, int port_num, int index,
	unsigned long mode, struct typec_altmode *alt)
	{
	unsigned long end;
	u32 event_mask;
	u8 mux_state;
	int ret;

	ret = cros_typec_get_mux_state(mode, alt);
	if (ret < 0)
	return ret;
	mux_state = (u8)ret;

	/* Clear any old mux set done event. */
	if (index == 0)
	event_mask = PD_STATUS_EVENT_MUX_0_SET_DONE;
	else
	event_mask = PD_STATUS_EVENT_MUX_1_SET_DONE;

	ret = cros_typec_send_clear_event(sdata, port_num, event_mask);
	if (ret < 0)
	return ret;

	/* Send the set command. */
	ret = cros_typec_cmd_mux_set(sdata, port_num, index, mux_state);
	if (ret < 0)
	return ret;

	/* Check for the mux set done event. */
	end = jiffies + msecs_to_jiffies(1000);
	do {
	if (cros_typec_check_event(sdata, port_num, event_mask))
	return 0;

	usleep_range(500, 1000);
	} while (time_before(jiffies, end));

	dev_err(sdata->dev, "Timed out waiting for mux set done on index: %d, state: %d\n",
	index, mux_state);

	return -ETIMEDOUT;
	}

	static int cros_typec_mode_switch_set(struct typec_mux_dev *mode_switch,
	struct typec_mux_state *state)
	{
	struct cros_typec_port *port = typec_mux_get_drvdata(mode_switch);

	/* Mode switches have index 0. */
	return cros_typec_configure_mux(port->sdata, port->port_num, 0, state->mode, state->alt);
	}

	static int cros_typec_retimer_set(struct typec_retimer retimer, struct typec_retimer_state state)
	{
	struct cros_typec_port *port = typec_retimer_get_drvdata(retimer);

	/* Retimers have index 1. */
	return cros_typec_configure_mux(port->sdata, port->port_num, 1, state->mode, state->alt);
	}

	static void cros_typec_unregister_switches(struct cros_typec_switch_data *sdata)
	{
	int i;

	for (i = 0; i < EC_USB_PD_MAX_PORTS; i++) {
	if (!sdata->ports[i])
	continue;
	typec_retimer_unregister(sdata->ports[i]->retimer);
	typec_mux_unregister(sdata->ports[i]->mode_switch);
	}
	}

	static int cros_typec_register_mode_switch(struct cros_typec_port *port,
	struct fwnode_handle *fwnode)
	{
	struct typec_mux_desc mode_switch_desc = {
	.fwnode = fwnode,
	.drvdata = port,
	.name = fwnode_get_name(fwnode),
	.set = cros_typec_mode_switch_set,
	};

	port->mode_switch = typec_mux_register(port->sdata->dev, &mode_switch_desc);

	return PTR_ERR_OR_ZERO(port->mode_switch);
	}

	static int cros_typec_register_retimer(struct cros_typec_port port, struct fwnode_handle fwnode)
	{
	struct typec_retimer_desc retimer_desc = {
	.fwnode = fwnode,
	.drvdata = port,
	.name = fwnode_get_name(fwnode),
	.set = cros_typec_retimer_set,
	};

	port->retimer = typec_retimer_register(port->sdata->dev, &retimer_desc);

	return PTR_ERR_OR_ZERO(port->retimer);
	}

	static int cros_typec_register_switches(struct cros_typec_switch_data *sdata)
	{
	struct cros_typec_port *port;
	struct device *dev = sdata->dev;
	struct fwnode_handle *fwnode;
	struct acpi_device *adev;
	unsigned long long index;
	int nports, ret;

	nports = device_get_child_node_count(dev);
	if (nports == 0) {
	dev_err(dev, "No switch devices found.\n");
	return -ENODEV;
	}

	device_for_each_child_node(dev, fwnode) {
	port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL);
	if (!port) {
	ret = -ENOMEM;
	goto err_switch;
	}

	adev = to_acpi_device_node(fwnode);
	if (!adev) {
	dev_err(fwnode->dev, "Couldn't get ACPI device handle\n");
	ret = -ENODEV;
	goto err_switch;
	}

	ret = acpi_evaluate_integer(adev->handle, "_ADR", NULL, &index);
	if (ACPI_FAILURE(ret)) {
	dev_err(fwnode->dev, "_ADR wasn't evaluated\n");
	ret = -ENODATA;
	goto err_switch;
	}

	if (index >= EC_USB_PD_MAX_PORTS) {
	dev_err(fwnode->dev, "Invalid port index number: %llu\n", index);
	ret = -EINVAL;
	goto err_switch;
	}
	port->sdata = sdata;
	port->port_num = index;
	sdata->ports[index] = port;

	if (fwnode_property_present(fwnode, "retimer-switch")) {
	ret = cros_typec_register_retimer(port, fwnode);
	if (ret) {
	dev_err(dev, "Retimer switch register failed\n");
	goto err_switch;
	}

	dev_dbg(dev, "Retimer switch registered for index %llu\n", index);
	}

	if (!fwnode_property_present(fwnode, "mode-switch"))
	continue;

	ret = cros_typec_register_mode_switch(port, fwnode);
	if (ret) {
	dev_err(dev, "Mode switch register failed\n");
	goto err_switch;
	}

	dev_dbg(dev, "Mode switch registered for index %llu\n", index);
	}

	return 0;
	err_switch:
	fwnode_handle_put(fwnode);
	cros_typec_unregister_switches(sdata);
	return ret;
	}

	static int cros_typec_switch_probe(struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	struct cros_typec_switch_data *sdata;

	sdata = devm_kzalloc(dev, sizeof(*sdata), GFP_KERNEL);
	if (!sdata)
	return -ENOMEM;

	sdata->dev = dev;
	sdata->ec = dev_get_drvdata(pdev->dev.parent);

	platform_set_drvdata(pdev, sdata);

	return cros_typec_register_switches(sdata);
	}

	static void cros_typec_switch_remove(struct platform_device *pdev)
	{
	struct cros_typec_switch_data *sdata = platform_get_drvdata(pdev);

	cros_typec_unregister_switches(sdata);
	}

	#ifdef CONFIG_ACPI
	static const struct acpi_device_id cros_typec_switch_acpi_id[] = {
	{ "GOOG001A", 0 },
	{}
	};
	MODULE_DEVICE_TABLE(acpi, cros_typec_switch_acpi_id);
	#endif

	static struct platform_driver cros_typec_switch_driver = {
	.driver = {
	.name = "cros-typec-switch",
	.acpi_match_table = ACPI_PTR(cros_typec_switch_acpi_id),
	},
	.probe = cros_typec_switch_probe,
	.remove_new = cros_typec_switch_remove,
	};

	module_platform_driver(cros_typec_switch_driver);

	MODULE_AUTHOR("Prashant Malani <pmalani@chromium.org>");
	MODULE_DESCRIPTION("ChromeOS EC Type-C Switch control");
	MODULE_LICENSE("GPL");