drivers/extcon/extcon-usbc-cros-ec.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 // ChromeOS Embedded Controller extcon
 //
 // Copyright (C) 2017 Google, Inc.
 // Author: Benson Leung <bleung@chromium.org>

 #include <linux/extcon-provider.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/notifier.h>
 #include <linux/of.h>
 #include <linux/platform_data/cros_ec_commands.h>
 #include <linux/platform_data/cros_ec_proto.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/sched.h>

 struct cros_ec_extcon_info {
 	struct device *dev;
 	struct extcon_dev *edev;

 	int port_id;

 	struct cros_ec_device *ec;

 	struct notifier_block notifier;

 	unsigned int dr; /* data role */
 	bool pr; /* power role (true if VBUS enabled) */
 	bool dp; /* DisplayPort enabled */
 	bool mux; /* SuperSpeed (usb3) enabled */
 	unsigned int power_type;
 };

 static const unsigned int usb_type_c_cable[] = {
 	EXTCON_USB,
 	EXTCON_USB_HOST,
 	EXTCON_DISP_DP,
 	EXTCON_NONE,
 };

 enum usb_data_roles {
 	DR_NONE,
 	DR_HOST,
 	DR_DEVICE,
 };

 /**
  * cros_ec_pd_command() - Send a command to the EC.
  * @info: pointer to struct cros_ec_extcon_info
  * @command: EC command
  * @version: EC command version
  * @outdata: EC command output data
  * @outsize: Size of outdata
  * @indata: EC command input data
  * @insize: Size of indata
  *
  * Return: 0 on success, <0 on failure.
  */
 static int cros_ec_pd_command(struct cros_ec_extcon_info *info,
 			      unsigned int command,
 			      unsigned int version,
 			      void *outdata,
 			      unsigned int outsize,
 			      void *indata,
 			      unsigned int insize)
 {
 	struct cros_ec_command *msg;
 	int ret;

 	msg = kzalloc(struct_size(msg, data, max(outsize, insize)), GFP_KERNEL);
 	if (!msg)
 		return -ENOMEM;

 	msg->version = version;
 	msg->command = command;
 	msg->outsize = outsize;
 	msg->insize = insize;

 	if (outsize)
 		memcpy(msg->data, outdata, outsize);

 	ret = cros_ec_cmd_xfer_status(info->ec, msg);
 	if (ret >= 0 && insize)
 		memcpy(indata, msg->data, insize);

 	kfree(msg);
 	return ret;
 }

 /**
  * cros_ec_usb_get_power_type() - Get power type info about PD device attached
  * to given port.
  * @info: pointer to struct cros_ec_extcon_info
  *
  * Return: power type on success, <0 on failure.
  */
 static int cros_ec_usb_get_power_type(struct cros_ec_extcon_info *info)
 {
 	struct ec_params_usb_pd_power_info req;
 	struct ec_response_usb_pd_power_info resp;
 	int ret;

 	req.port = info->port_id;
 	ret = cros_ec_pd_command(info, EC_CMD_USB_PD_POWER_INFO, 0,
 				 &req, sizeof(req), &resp, sizeof(resp));
 	if (ret < 0)
 		return ret;

 	return resp.type;
 }

 /**
  * cros_ec_usb_get_pd_mux_state() - Get PD mux state for given port.
  * @info: pointer to struct cros_ec_extcon_info
  *
  * Return: PD mux state on success, <0 on failure.
  */
 static int cros_ec_usb_get_pd_mux_state(struct cros_ec_extcon_info *info)
 {
 	struct ec_params_usb_pd_mux_info req;
 	struct ec_response_usb_pd_mux_info resp;
 	int ret;

 	req.port = info->port_id;
 	ret = cros_ec_pd_command(info, EC_CMD_USB_PD_MUX_INFO, 0,
 				 &req, sizeof(req),
 				 &resp, sizeof(resp));
 	if (ret < 0)
 		return ret;

 	return resp.flags;
 }

 /**
  * cros_ec_usb_get_role() - Get role info about possible PD device attached to a
  * given port.
  * @info: pointer to struct cros_ec_extcon_info
  * @polarity: pointer to cable polarity (return value)
  *
  * Return: role info on success, -ENOTCONN if no cable is connected, <0 on
  * failure.
  */
 static int cros_ec_usb_get_role(struct cros_ec_extcon_info *info,
 				bool *polarity)
 {
 	struct ec_params_usb_pd_control pd_control;
 	struct ec_response_usb_pd_control_v1 resp;
 	int ret;

 	pd_control.port = info->port_id;
 	pd_control.role = USB_PD_CTRL_ROLE_NO_CHANGE;
 	pd_control.mux = USB_PD_CTRL_MUX_NO_CHANGE;
 	pd_control.swap = USB_PD_CTRL_SWAP_NONE;
 	ret = cros_ec_pd_command(info, EC_CMD_USB_PD_CONTROL, 1,
 				 &pd_control, sizeof(pd_control),
 				 &resp, sizeof(resp));
 	if (ret < 0)
 		return ret;

 	if (!(resp.enabled & PD_CTRL_RESP_ENABLED_CONNECTED))
 		return -ENOTCONN;

 	*polarity = resp.polarity;

 	return resp.role;
 }

 /**
  * cros_ec_pd_get_num_ports() - Get number of EC charge ports.
  * @info: pointer to struct cros_ec_extcon_info
  *
  * Return: number of ports on success, <0 on failure.
  */
 static int cros_ec_pd_get_num_ports(struct cros_ec_extcon_info *info)
 {
 	struct ec_response_usb_pd_ports resp;
 	int ret;

 	ret = cros_ec_pd_command(info, EC_CMD_USB_PD_PORTS,
 				 0, NULL, 0, &resp, sizeof(resp));
 	if (ret < 0)
 		return ret;

 	return resp.num_ports;
 }

 static const char *cros_ec_usb_role_string(unsigned int role)
 {
 	return role == DR_NONE ? "DISCONNECTED" :
 		(role == DR_HOST ? "DFP" : "UFP");
 }

 static const char *cros_ec_usb_power_type_string(unsigned int type)
 {
 	switch (type) {
 	case USB_CHG_TYPE_NONE:
 		return "USB_CHG_TYPE_NONE";
 	case USB_CHG_TYPE_PD:
 		return "USB_CHG_TYPE_PD";
 	case USB_CHG_TYPE_PROPRIETARY:
 		return "USB_CHG_TYPE_PROPRIETARY";
 	case USB_CHG_TYPE_C:
 		return "USB_CHG_TYPE_C";
 	case USB_CHG_TYPE_BC12_DCP:
 		return "USB_CHG_TYPE_BC12_DCP";
 	case USB_CHG_TYPE_BC12_CDP:
 		return "USB_CHG_TYPE_BC12_CDP";
 	case USB_CHG_TYPE_BC12_SDP:
 		return "USB_CHG_TYPE_BC12_SDP";
 	case USB_CHG_TYPE_OTHER:
 		return "USB_CHG_TYPE_OTHER";
 	case USB_CHG_TYPE_VBUS:
 		return "USB_CHG_TYPE_VBUS";
 	case USB_CHG_TYPE_UNKNOWN:
 		return "USB_CHG_TYPE_UNKNOWN";
 	default:
 		return "USB_CHG_TYPE_UNKNOWN";
 	}
 }

 static bool cros_ec_usb_power_type_is_wall_wart(unsigned int type,
 						unsigned int role)
 {
 	switch (type) {
 	/* FIXME : Guppy, Donnettes, and other chargers will be miscategorized
 	 * because they identify with USB_CHG_TYPE_C, but we can't return true
 	 * here from that code because that breaks Suzy-Q and other kinds of
 	 * USB Type-C cables and peripherals.
 	 */
 	case USB_CHG_TYPE_PROPRIETARY:
 	case USB_CHG_TYPE_BC12_DCP:
 		return true;
 	case USB_CHG_TYPE_PD:
 	case USB_CHG_TYPE_C:
 	case USB_CHG_TYPE_BC12_CDP:
 	case USB_CHG_TYPE_BC12_SDP:
 	case USB_CHG_TYPE_OTHER:
 	case USB_CHG_TYPE_VBUS:
 	case USB_CHG_TYPE_UNKNOWN:
 	case USB_CHG_TYPE_NONE:
 	default:
 		return false;
 	}
 }

 static int extcon_cros_ec_detect_cable(struct cros_ec_extcon_info *info,
 				       bool force)
 {
 	struct device *dev = info->dev;
 	int role, power_type;
 	unsigned int dr = DR_NONE;
 	bool pr = false;
 	bool polarity = false;
 	bool dp = false;
 	bool mux = false;
 	bool hpd = false;

 	power_type = cros_ec_usb_get_power_type(info);
 	if (power_type < 0) {
 		dev_err(dev, "failed getting power type err = %d\n",
 			power_type);
 		return power_type;
 	}

 	role = cros_ec_usb_get_role(info, &polarity);
 	if (role < 0) {
 		if (role != -ENOTCONN) {
 			dev_err(dev, "failed getting role err = %d\n", role);
 			return role;
 		}
 		dev_dbg(dev, "disconnected\n");
 	} else {
 		int pd_mux_state;

 		dr = (role & PD_CTRL_RESP_ROLE_DATA) ? DR_HOST : DR_DEVICE;
 		pr = (role & PD_CTRL_RESP_ROLE_POWER);
 		pd_mux_state = cros_ec_usb_get_pd_mux_state(info);
 		if (pd_mux_state < 0)
 			pd_mux_state = USB_PD_MUX_USB_ENABLED;

 		dp = pd_mux_state & USB_PD_MUX_DP_ENABLED;
 		mux = pd_mux_state & USB_PD_MUX_USB_ENABLED;
 		hpd = pd_mux_state & USB_PD_MUX_HPD_IRQ;

 		dev_dbg(dev,
 			"connected role 0x%x pwr type %d dr %d pr %d pol %d mux %d dp %d hpd %d\n",
 			role, power_type, dr, pr, polarity, mux, dp, hpd);
 	}

 	/*
 	 * When there is no USB host (e.g. USB PD charger),
 	 * we are not really a UFP for the AP.
 	 */
 	if (dr == DR_DEVICE &&
 	    cros_ec_usb_power_type_is_wall_wart(power_type, role))
 		dr = DR_NONE;

 	if (force || info->dr != dr || info->pr != pr || info->dp != dp ||
 	    info->mux != mux || info->power_type != power_type) {
 		bool host_connected = false, device_connected = false;

 		dev_dbg(dev, "Type/Role switch! type = %s role = %s\n",
 			cros_ec_usb_power_type_string(power_type),
 			cros_ec_usb_role_string(dr));
 		info->dr = dr;
 		info->pr = pr;
 		info->dp = dp;
 		info->mux = mux;
 		info->power_type = power_type;

 		if (dr == DR_DEVICE)
 			device_connected = true;
 		else if (dr == DR_HOST)
 			host_connected = true;

 		extcon_set_state(info->edev, EXTCON_USB, device_connected);
 		extcon_set_state(info->edev, EXTCON_USB_HOST, host_connected);
 		extcon_set_state(info->edev, EXTCON_DISP_DP, dp);
 		extcon_set_property(info->edev, EXTCON_USB,
 				    EXTCON_PROP_USB_VBUS,
 				    (union extcon_property_value)(int)pr);
 		extcon_set_property(info->edev, EXTCON_USB_HOST,
 				    EXTCON_PROP_USB_VBUS,
 				    (union extcon_property_value)(int)pr);
 		extcon_set_property(info->edev, EXTCON_USB,
 				    EXTCON_PROP_USB_TYPEC_POLARITY,
 				    (union extcon_property_value)(int)polarity);
 		extcon_set_property(info->edev, EXTCON_USB_HOST,
 				    EXTCON_PROP_USB_TYPEC_POLARITY,
 				    (union extcon_property_value)(int)polarity);
 		extcon_set_property(info->edev, EXTCON_DISP_DP,
 				    EXTCON_PROP_USB_TYPEC_POLARITY,
 				    (union extcon_property_value)(int)polarity);
 		extcon_set_property(info->edev, EXTCON_USB,
 				    EXTCON_PROP_USB_SS,
 				    (union extcon_property_value)(int)mux);
 		extcon_set_property(info->edev, EXTCON_USB_HOST,
 				    EXTCON_PROP_USB_SS,
 				    (union extcon_property_value)(int)mux);
 		extcon_set_property(info->edev, EXTCON_DISP_DP,
 				    EXTCON_PROP_USB_SS,
 				    (union extcon_property_value)(int)mux);
 		extcon_set_property(info->edev, EXTCON_DISP_DP,
 				    EXTCON_PROP_DISP_HPD,
 				    (union extcon_property_value)(int)hpd);

 		extcon_sync(info->edev, EXTCON_USB);
 		extcon_sync(info->edev, EXTCON_USB_HOST);
 		extcon_sync(info->edev, EXTCON_DISP_DP);

 	} else if (hpd) {
 		extcon_set_property(info->edev, EXTCON_DISP_DP,
 				    EXTCON_PROP_DISP_HPD,
 				    (union extcon_property_value)(int)hpd);
 		extcon_sync(info->edev, EXTCON_DISP_DP);
 	}

 	return 0;
 }

 static int extcon_cros_ec_event(struct notifier_block *nb,
 				unsigned long queued_during_suspend,
 				void *_notify)
 {
 	struct cros_ec_extcon_info *info;
 	struct cros_ec_device *ec;
 	u32 host_event;

 	info = container_of(nb, struct cros_ec_extcon_info, notifier);
 	ec = info->ec;

 	host_event = cros_ec_get_host_event(ec);
 	if (host_event & (EC_HOST_EVENT_MASK(EC_HOST_EVENT_PD_MCU) |
 			  EC_HOST_EVENT_MASK(EC_HOST_EVENT_USB_MUX))) {
 		extcon_cros_ec_detect_cable(info, false);
 		return NOTIFY_OK;
 	}

 	return NOTIFY_DONE;
 }

 static int extcon_cros_ec_probe(struct platform_device *pdev)
 {
 	struct cros_ec_extcon_info *info;
 	struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent);
 	struct device *dev = &pdev->dev;
 	struct device_node *np = dev->of_node;
 	int numports, ret;

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

 	info->dev = dev;
 	info->ec = ec;

 	if (np) {
 		u32 port;

 		ret = of_property_read_u32(np, "google,usb-port-id", &port);
 		if (ret < 0) {
 			dev_err(dev, "Missing google,usb-port-id property\n");
 			return ret;
 		}
 		info->port_id = port;
 	} else {
 		info->port_id = pdev->id;
 	}

 	numports = cros_ec_pd_get_num_ports(info);
 	if (numports < 0) {
 		dev_err(dev, "failed getting number of ports! ret = %d\n",
 			numports);
 		return numports;
 	}

 	if (info->port_id >= numports) {
 		dev_err(dev, "This system only supports %d ports\n", numports);
 		return -ENODEV;
 	}

 	info->edev = devm_extcon_dev_allocate(dev, usb_type_c_cable);
 	if (IS_ERR(info->edev)) {
 		dev_err(dev, "failed to allocate extcon device\n");
 		return -ENOMEM;
 	}

 	ret = devm_extcon_dev_register(dev, info->edev);
 	if (ret < 0) {
 		dev_err(dev, "failed to register extcon device\n");
 		return ret;
 	}

 	extcon_set_property_capability(info->edev, EXTCON_USB,
 				       EXTCON_PROP_USB_VBUS);
 	extcon_set_property_capability(info->edev, EXTCON_USB_HOST,
 				       EXTCON_PROP_USB_VBUS);
 	extcon_set_property_capability(info->edev, EXTCON_USB,
 				       EXTCON_PROP_USB_TYPEC_POLARITY);
 	extcon_set_property_capability(info->edev, EXTCON_USB_HOST,
 				       EXTCON_PROP_USB_TYPEC_POLARITY);
 	extcon_set_property_capability(info->edev, EXTCON_DISP_DP,
 				       EXTCON_PROP_USB_TYPEC_POLARITY);
 	extcon_set_property_capability(info->edev, EXTCON_USB,
 				       EXTCON_PROP_USB_SS);
 	extcon_set_property_capability(info->edev, EXTCON_USB_HOST,
 				       EXTCON_PROP_USB_SS);
 	extcon_set_property_capability(info->edev, EXTCON_DISP_DP,
 				       EXTCON_PROP_USB_SS);
 	extcon_set_property_capability(info->edev, EXTCON_DISP_DP,
 				       EXTCON_PROP_DISP_HPD);

 	info->dr = DR_NONE;
 	info->pr = false;

 	platform_set_drvdata(pdev, info);

 	/* Get PD events from the EC */
 	info->notifier.notifier_call = extcon_cros_ec_event;
 	ret = blocking_notifier_chain_register(&info->ec->event_notifier,
 					       &info->notifier);
 	if (ret < 0) {
 		dev_err(dev, "failed to register notifier\n");
 		return ret;
 	}

 	/* Perform initial detection */
 	ret = extcon_cros_ec_detect_cable(info, true);
 	if (ret < 0) {
 		dev_err(dev, "failed to detect initial cable state\n");
 		goto unregister_notifier;
 	}

 	return 0;

 unregister_notifier:
 	blocking_notifier_chain_unregister(&info->ec->event_notifier,
 					   &info->notifier);
 	return ret;
 }

 static void extcon_cros_ec_remove(struct platform_device *pdev)
 {
 	struct cros_ec_extcon_info *info = platform_get_drvdata(pdev);

 	blocking_notifier_chain_unregister(&info->ec->event_notifier,
 					   &info->notifier);
 }

 #ifdef CONFIG_PM_SLEEP
 static int extcon_cros_ec_suspend(struct device *dev)
 {
 	return 0;
 }

 static int extcon_cros_ec_resume(struct device *dev)
 {
 	int ret;
 	struct cros_ec_extcon_info *info = dev_get_drvdata(dev);

 	ret = extcon_cros_ec_detect_cable(info, true);
 	if (ret < 0)
 		dev_err(dev, "failed to detect cable state on resume\n");

 	return 0;
 }

 static const struct dev_pm_ops extcon_cros_ec_dev_pm_ops = {
 	SET_SYSTEM_SLEEP_PM_OPS(extcon_cros_ec_suspend, extcon_cros_ec_resume)
 };

 #define DEV_PM_OPS	(&extcon_cros_ec_dev_pm_ops)
 #else
 #define DEV_PM_OPS	NULL
 #endif /* CONFIG_PM_SLEEP */

 #ifdef CONFIG_OF
 static const struct of_device_id extcon_cros_ec_of_match[] = {
 	{ .compatible = "google,extcon-usbc-cros-ec" },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, extcon_cros_ec_of_match);
 #endif /* CONFIG_OF */

 static struct platform_driver extcon_cros_ec_driver = {
 	.driver = {
 		.name  = "extcon-usbc-cros-ec",
 		.of_match_table = of_match_ptr(extcon_cros_ec_of_match),
 		.pm = DEV_PM_OPS,
 	},
 	.remove  = extcon_cros_ec_remove,
 	.probe   = extcon_cros_ec_probe,
 };

 module_platform_driver(extcon_cros_ec_driver);

 MODULE_DESCRIPTION("ChromeOS Embedded Controller extcon driver");
 MODULE_AUTHOR("Benson Leung <bleung@chromium.org>");
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0
	// ChromeOS Embedded Controller extcon
	//
	// Copyright (C) 2017 Google, Inc.
	// Author: Benson Leung <bleung@chromium.org>

	#include <linux/extcon-provider.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/notifier.h>
	#include <linux/of.h>
	#include <linux/platform_data/cros_ec_commands.h>
	#include <linux/platform_data/cros_ec_proto.h>
	#include <linux/platform_device.h>
	#include <linux/slab.h>
	#include <linux/sched.h>

	struct cros_ec_extcon_info {
	struct device *dev;
	struct extcon_dev *edev;

	int port_id;

	struct cros_ec_device *ec;

	struct notifier_block notifier;

	unsigned int dr; /* data role */
	bool pr; /* power role (true if VBUS enabled) */
	bool dp; /* DisplayPort enabled */
	bool mux; /* SuperSpeed (usb3) enabled */
	unsigned int power_type;
	};

	static const unsigned int usb_type_c_cable[] = {
	EXTCON_USB,
	EXTCON_USB_HOST,
	EXTCON_DISP_DP,
	EXTCON_NONE,
	};

	enum usb_data_roles {
	DR_NONE,
	DR_HOST,
	DR_DEVICE,
	};

	/**
	* cros_ec_pd_command() - Send a command to the EC.
	* @info: pointer to struct cros_ec_extcon_info
	* @command: EC command
	* @version: EC command version
	* @outdata: EC command output data
	* @outsize: Size of outdata
	* @indata: EC command input data
	* @insize: Size of indata
	*
	* Return: 0 on success, <0 on failure.
	*/
	static int cros_ec_pd_command(struct cros_ec_extcon_info *info,
	unsigned int command,
	unsigned int version,
	void *outdata,
	unsigned int outsize,
	void *indata,
	unsigned int insize)
	{
	struct cros_ec_command *msg;
	int ret;

	msg = kzalloc(struct_size(msg, data, max(outsize, insize)), GFP_KERNEL);
	if (!msg)
	return -ENOMEM;

	msg->version = version;
	msg->command = command;
	msg->outsize = outsize;
	msg->insize = insize;

	if (outsize)
	memcpy(msg->data, outdata, outsize);

	ret = cros_ec_cmd_xfer_status(info->ec, msg);
	if (ret >= 0 && insize)
	memcpy(indata, msg->data, insize);

	kfree(msg);
	return ret;
	}

	/**
	* cros_ec_usb_get_power_type() - Get power type info about PD device attached
	* to given port.
	* @info: pointer to struct cros_ec_extcon_info
	*
	* Return: power type on success, <0 on failure.
	*/
	static int cros_ec_usb_get_power_type(struct cros_ec_extcon_info *info)
	{
	struct ec_params_usb_pd_power_info req;
	struct ec_response_usb_pd_power_info resp;
	int ret;

	req.port = info->port_id;
	ret = cros_ec_pd_command(info, EC_CMD_USB_PD_POWER_INFO, 0,
	&req, sizeof(req), &resp, sizeof(resp));
	if (ret < 0)
	return ret;

	return resp.type;
	}

	/**
	* cros_ec_usb_get_pd_mux_state() - Get PD mux state for given port.
	* @info: pointer to struct cros_ec_extcon_info
	*
	* Return: PD mux state on success, <0 on failure.
	*/
	static int cros_ec_usb_get_pd_mux_state(struct cros_ec_extcon_info *info)
	{
	struct ec_params_usb_pd_mux_info req;
	struct ec_response_usb_pd_mux_info resp;
	int ret;

	req.port = info->port_id;
	ret = cros_ec_pd_command(info, EC_CMD_USB_PD_MUX_INFO, 0,
	&req, sizeof(req),
	&resp, sizeof(resp));
	if (ret < 0)
	return ret;

	return resp.flags;
	}

	/**
	* cros_ec_usb_get_role() - Get role info about possible PD device attached to a
	* given port.
	* @info: pointer to struct cros_ec_extcon_info
	* @polarity: pointer to cable polarity (return value)
	*
	* Return: role info on success, -ENOTCONN if no cable is connected, <0 on
	* failure.
	*/
	static int cros_ec_usb_get_role(struct cros_ec_extcon_info *info,
	bool *polarity)
	{
	struct ec_params_usb_pd_control pd_control;
	struct ec_response_usb_pd_control_v1 resp;
	int ret;

	pd_control.port = info->port_id;
	pd_control.role = USB_PD_CTRL_ROLE_NO_CHANGE;
	pd_control.mux = USB_PD_CTRL_MUX_NO_CHANGE;
	pd_control.swap = USB_PD_CTRL_SWAP_NONE;
	ret = cros_ec_pd_command(info, EC_CMD_USB_PD_CONTROL, 1,
	&pd_control, sizeof(pd_control),
	&resp, sizeof(resp));
	if (ret < 0)
	return ret;

	if (!(resp.enabled & PD_CTRL_RESP_ENABLED_CONNECTED))
	return -ENOTCONN;

	*polarity = resp.polarity;

	return resp.role;
	}

	/**
	* cros_ec_pd_get_num_ports() - Get number of EC charge ports.
	* @info: pointer to struct cros_ec_extcon_info
	*
	* Return: number of ports on success, <0 on failure.
	*/
	static int cros_ec_pd_get_num_ports(struct cros_ec_extcon_info *info)
	{
	struct ec_response_usb_pd_ports resp;
	int ret;

	ret = cros_ec_pd_command(info, EC_CMD_USB_PD_PORTS,
	0, NULL, 0, &resp, sizeof(resp));
	if (ret < 0)
	return ret;

	return resp.num_ports;
	}

	static const char *cros_ec_usb_role_string(unsigned int role)
	{
	return role == DR_NONE ? "DISCONNECTED" :
	(role == DR_HOST ? "DFP" : "UFP");
	}

	static const char *cros_ec_usb_power_type_string(unsigned int type)
	{
	switch (type) {
	case USB_CHG_TYPE_NONE:
	return "USB_CHG_TYPE_NONE";
	case USB_CHG_TYPE_PD:
	return "USB_CHG_TYPE_PD";
	case USB_CHG_TYPE_PROPRIETARY:
	return "USB_CHG_TYPE_PROPRIETARY";
	case USB_CHG_TYPE_C:
	return "USB_CHG_TYPE_C";
	case USB_CHG_TYPE_BC12_DCP:
	return "USB_CHG_TYPE_BC12_DCP";
	case USB_CHG_TYPE_BC12_CDP:
	return "USB_CHG_TYPE_BC12_CDP";
	case USB_CHG_TYPE_BC12_SDP:
	return "USB_CHG_TYPE_BC12_SDP";
	case USB_CHG_TYPE_OTHER:
	return "USB_CHG_TYPE_OTHER";
	case USB_CHG_TYPE_VBUS:
	return "USB_CHG_TYPE_VBUS";
	case USB_CHG_TYPE_UNKNOWN:
	return "USB_CHG_TYPE_UNKNOWN";
	default:
	return "USB_CHG_TYPE_UNKNOWN";
	}
	}

	static bool cros_ec_usb_power_type_is_wall_wart(unsigned int type,
	unsigned int role)
	{
	switch (type) {
	/* FIXME : Guppy, Donnettes, and other chargers will be miscategorized
	* because they identify with USB_CHG_TYPE_C, but we can't return true
	* here from that code because that breaks Suzy-Q and other kinds of
	* USB Type-C cables and peripherals.
	*/
	case USB_CHG_TYPE_PROPRIETARY:
	case USB_CHG_TYPE_BC12_DCP:
	return true;
	case USB_CHG_TYPE_PD:
	case USB_CHG_TYPE_C:
	case USB_CHG_TYPE_BC12_CDP:
	case USB_CHG_TYPE_BC12_SDP:
	case USB_CHG_TYPE_OTHER:
	case USB_CHG_TYPE_VBUS:
	case USB_CHG_TYPE_UNKNOWN:
	case USB_CHG_TYPE_NONE:
	default:
	return false;
	}
	}

	static int extcon_cros_ec_detect_cable(struct cros_ec_extcon_info *info,
	bool force)
	{
	struct device *dev = info->dev;
	int role, power_type;
	unsigned int dr = DR_NONE;
	bool pr = false;
	bool polarity = false;
	bool dp = false;
	bool mux = false;
	bool hpd = false;

	power_type = cros_ec_usb_get_power_type(info);
	if (power_type < 0) {
	dev_err(dev, "failed getting power type err = %d\n",
	power_type);
	return power_type;
	}

	role = cros_ec_usb_get_role(info, &polarity);
	if (role < 0) {
	if (role != -ENOTCONN) {
	dev_err(dev, "failed getting role err = %d\n", role);
	return role;
	}
	dev_dbg(dev, "disconnected\n");
	} else {
	int pd_mux_state;

	dr = (role & PD_CTRL_RESP_ROLE_DATA) ? DR_HOST : DR_DEVICE;
	pr = (role & PD_CTRL_RESP_ROLE_POWER);
	pd_mux_state = cros_ec_usb_get_pd_mux_state(info);
	if (pd_mux_state < 0)
	pd_mux_state = USB_PD_MUX_USB_ENABLED;

	dp = pd_mux_state & USB_PD_MUX_DP_ENABLED;
	mux = pd_mux_state & USB_PD_MUX_USB_ENABLED;
	hpd = pd_mux_state & USB_PD_MUX_HPD_IRQ;

	dev_dbg(dev,
	"connected role 0x%x pwr type %d dr %d pr %d pol %d mux %d dp %d hpd %d\n",
	role, power_type, dr, pr, polarity, mux, dp, hpd);
	}

	/*
	* When there is no USB host (e.g. USB PD charger),
	* we are not really a UFP for the AP.
	*/
	if (dr == DR_DEVICE &&
	cros_ec_usb_power_type_is_wall_wart(power_type, role))
	dr = DR_NONE;

	if (force \|\| info->dr != dr \|\| info->pr != pr \|\| info->dp != dp \|\|
	info->mux != mux \|\| info->power_type != power_type) {
	bool host_connected = false, device_connected = false;

	dev_dbg(dev, "Type/Role switch! type = %s role = %s\n",
	cros_ec_usb_power_type_string(power_type),
	cros_ec_usb_role_string(dr));
	info->dr = dr;
	info->pr = pr;
	info->dp = dp;
	info->mux = mux;
	info->power_type = power_type;

	if (dr == DR_DEVICE)
	device_connected = true;
	else if (dr == DR_HOST)
	host_connected = true;

	extcon_set_state(info->edev, EXTCON_USB, device_connected);
	extcon_set_state(info->edev, EXTCON_USB_HOST, host_connected);
	extcon_set_state(info->edev, EXTCON_DISP_DP, dp);
	extcon_set_property(info->edev, EXTCON_USB,
	EXTCON_PROP_USB_VBUS,
	(union extcon_property_value)(int)pr);
	extcon_set_property(info->edev, EXTCON_USB_HOST,
	EXTCON_PROP_USB_VBUS,
	(union extcon_property_value)(int)pr);
	extcon_set_property(info->edev, EXTCON_USB,
	EXTCON_PROP_USB_TYPEC_POLARITY,
	(union extcon_property_value)(int)polarity);
	extcon_set_property(info->edev, EXTCON_USB_HOST,
	EXTCON_PROP_USB_TYPEC_POLARITY,
	(union extcon_property_value)(int)polarity);
	extcon_set_property(info->edev, EXTCON_DISP_DP,
	EXTCON_PROP_USB_TYPEC_POLARITY,
	(union extcon_property_value)(int)polarity);
	extcon_set_property(info->edev, EXTCON_USB,
	EXTCON_PROP_USB_SS,
	(union extcon_property_value)(int)mux);
	extcon_set_property(info->edev, EXTCON_USB_HOST,
	EXTCON_PROP_USB_SS,
	(union extcon_property_value)(int)mux);
	extcon_set_property(info->edev, EXTCON_DISP_DP,
	EXTCON_PROP_USB_SS,
	(union extcon_property_value)(int)mux);
	extcon_set_property(info->edev, EXTCON_DISP_DP,
	EXTCON_PROP_DISP_HPD,
	(union extcon_property_value)(int)hpd);

	extcon_sync(info->edev, EXTCON_USB);
	extcon_sync(info->edev, EXTCON_USB_HOST);
	extcon_sync(info->edev, EXTCON_DISP_DP);

	} else if (hpd) {
	extcon_set_property(info->edev, EXTCON_DISP_DP,
	EXTCON_PROP_DISP_HPD,
	(union extcon_property_value)(int)hpd);
	extcon_sync(info->edev, EXTCON_DISP_DP);
	}

	return 0;
	}

	static int extcon_cros_ec_event(struct notifier_block *nb,
	unsigned long queued_during_suspend,
	void *_notify)
	{
	struct cros_ec_extcon_info *info;
	struct cros_ec_device *ec;
	u32 host_event;

	info = container_of(nb, struct cros_ec_extcon_info, notifier);
	ec = info->ec;

	host_event = cros_ec_get_host_event(ec);
	if (host_event & (EC_HOST_EVENT_MASK(EC_HOST_EVENT_PD_MCU) \|
	EC_HOST_EVENT_MASK(EC_HOST_EVENT_USB_MUX))) {
	extcon_cros_ec_detect_cable(info, false);
	return NOTIFY_OK;
	}

	return NOTIFY_DONE;
	}

	static int extcon_cros_ec_probe(struct platform_device *pdev)
	{
	struct cros_ec_extcon_info *info;
	struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent);
	struct device *dev = &pdev->dev;
	struct device_node *np = dev->of_node;
	int numports, ret;

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

	info->dev = dev;
	info->ec = ec;

	if (np) {
	u32 port;

	ret = of_property_read_u32(np, "google,usb-port-id", &port);
	if (ret < 0) {
	dev_err(dev, "Missing google,usb-port-id property\n");
	return ret;
	}
	info->port_id = port;
	} else {
	info->port_id = pdev->id;
	}

	numports = cros_ec_pd_get_num_ports(info);
	if (numports < 0) {
	dev_err(dev, "failed getting number of ports! ret = %d\n",
	numports);
	return numports;
	}

	if (info->port_id >= numports) {
	dev_err(dev, "This system only supports %d ports\n", numports);
	return -ENODEV;
	}

	info->edev = devm_extcon_dev_allocate(dev, usb_type_c_cable);
	if (IS_ERR(info->edev)) {
	dev_err(dev, "failed to allocate extcon device\n");
	return -ENOMEM;
	}

	ret = devm_extcon_dev_register(dev, info->edev);
	if (ret < 0) {
	dev_err(dev, "failed to register extcon device\n");
	return ret;
	}

	extcon_set_property_capability(info->edev, EXTCON_USB,
	EXTCON_PROP_USB_VBUS);
	extcon_set_property_capability(info->edev, EXTCON_USB_HOST,
	EXTCON_PROP_USB_VBUS);
	extcon_set_property_capability(info->edev, EXTCON_USB,
	EXTCON_PROP_USB_TYPEC_POLARITY);
	extcon_set_property_capability(info->edev, EXTCON_USB_HOST,
	EXTCON_PROP_USB_TYPEC_POLARITY);
	extcon_set_property_capability(info->edev, EXTCON_DISP_DP,
	EXTCON_PROP_USB_TYPEC_POLARITY);
	extcon_set_property_capability(info->edev, EXTCON_USB,
	EXTCON_PROP_USB_SS);
	extcon_set_property_capability(info->edev, EXTCON_USB_HOST,
	EXTCON_PROP_USB_SS);
	extcon_set_property_capability(info->edev, EXTCON_DISP_DP,
	EXTCON_PROP_USB_SS);
	extcon_set_property_capability(info->edev, EXTCON_DISP_DP,
	EXTCON_PROP_DISP_HPD);

	info->dr = DR_NONE;
	info->pr = false;

	platform_set_drvdata(pdev, info);

	/* Get PD events from the EC */
	info->notifier.notifier_call = extcon_cros_ec_event;
	ret = blocking_notifier_chain_register(&info->ec->event_notifier,
	&info->notifier);
	if (ret < 0) {
	dev_err(dev, "failed to register notifier\n");
	return ret;
	}

	/* Perform initial detection */
	ret = extcon_cros_ec_detect_cable(info, true);
	if (ret < 0) {
	dev_err(dev, "failed to detect initial cable state\n");
	goto unregister_notifier;
	}

	return 0;

	unregister_notifier:
	blocking_notifier_chain_unregister(&info->ec->event_notifier,
	&info->notifier);
	return ret;
	}

	static void extcon_cros_ec_remove(struct platform_device *pdev)
	{
	struct cros_ec_extcon_info *info = platform_get_drvdata(pdev);

	blocking_notifier_chain_unregister(&info->ec->event_notifier,
	&info->notifier);
	}

	#ifdef CONFIG_PM_SLEEP
	static int extcon_cros_ec_suspend(struct device *dev)
	{
	return 0;
	}

	static int extcon_cros_ec_resume(struct device *dev)
	{
	int ret;
	struct cros_ec_extcon_info *info = dev_get_drvdata(dev);

	ret = extcon_cros_ec_detect_cable(info, true);
	if (ret < 0)
	dev_err(dev, "failed to detect cable state on resume\n");

	return 0;
	}

	static const struct dev_pm_ops extcon_cros_ec_dev_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(extcon_cros_ec_suspend, extcon_cros_ec_resume)
	};

	#define DEV_PM_OPS (&extcon_cros_ec_dev_pm_ops)
	#else
	#define DEV_PM_OPS NULL
	#endif /* CONFIG_PM_SLEEP */

	#ifdef CONFIG_OF
	static const struct of_device_id extcon_cros_ec_of_match[] = {
	{ .compatible = "google,extcon-usbc-cros-ec" },
	{ /* sentinel */ }
	};
	MODULE_DEVICE_TABLE(of, extcon_cros_ec_of_match);
	#endif /* CONFIG_OF */

	static struct platform_driver extcon_cros_ec_driver = {
	.driver = {
	.name = "extcon-usbc-cros-ec",
	.of_match_table = of_match_ptr(extcon_cros_ec_of_match),
	.pm = DEV_PM_OPS,
	},
	.remove = extcon_cros_ec_remove,
	.probe = extcon_cros_ec_probe,
	};

	module_platform_driver(extcon_cros_ec_driver);

	MODULE_DESCRIPTION("ChromeOS Embedded Controller extcon driver");
	MODULE_AUTHOR("Benson Leung <bleung@chromium.org>");
	MODULE_LICENSE("GPL v2");