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

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * ChromeOS EC multi-function device
  *
  * Copyright (C) 2012 Google, Inc
  *
  * The ChromeOS EC multi function device is used to mux all the requests
  * to the EC device for its multiple features: keyboard controller,
  * battery charging and regulator control, firmware update.
  */

 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/of_platform.h>
 #include <linux/platform_data/cros_ec_commands.h>
 #include <linux/platform_data/cros_ec_proto.h>
 #include <linux/slab.h>
 #include <linux/suspend.h>

 #include "cros_ec.h"

 static struct cros_ec_platform ec_p = {
 	.ec_name = CROS_EC_DEV_NAME,
 	.cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_EC_INDEX),
 };

 static struct cros_ec_platform pd_p = {
 	.ec_name = CROS_EC_DEV_PD_NAME,
 	.cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_PD_INDEX),
 };

 /**
  * cros_ec_irq_handler() - top half part of the interrupt handler
  * @irq: IRQ id
  * @data: (ec_dev) Device with events to process.
  *
  * Return: Wakeup the bottom half
  */
 static irqreturn_t cros_ec_irq_handler(int irq, void *data)
 {
 	struct cros_ec_device *ec_dev = data;

 	ec_dev->last_event_time = cros_ec_get_time_ns();

 	return IRQ_WAKE_THREAD;
 }

 /**
  * cros_ec_handle_event() - process and forward pending events on EC
  * @ec_dev: Device with events to process.
  *
  * Call this function in a loop when the kernel is notified that the EC has
  * pending events.
  *
  * Return: true if more events are still pending and this function should be
  * called again.
  */
 static bool cros_ec_handle_event(struct cros_ec_device *ec_dev)
 {
 	bool wake_event;
 	bool ec_has_more_events;
 	int ret;

 	ret = cros_ec_get_next_event(ec_dev, &wake_event, &ec_has_more_events);

 	/*
 	 * Signal only if wake host events or any interrupt if
 	 * cros_ec_get_next_event() returned an error (default value for
 	 * wake_event is true)
 	 */
 	if (wake_event && device_may_wakeup(ec_dev->dev))
 		pm_wakeup_event(ec_dev->dev, 0);

 	if (ret > 0)
 		blocking_notifier_call_chain(&ec_dev->event_notifier,
 					     0, ec_dev);

 	return ec_has_more_events;
 }

 /**
  * cros_ec_irq_thread() - bottom half part of the interrupt handler
  * @irq: IRQ id
  * @data: (ec_dev) Device with events to process.
  *
  * Return: Interrupt handled.
  */
 irqreturn_t cros_ec_irq_thread(int irq, void *data)
 {
 	struct cros_ec_device *ec_dev = data;
 	bool ec_has_more_events;

 	do {
 		ec_has_more_events = cros_ec_handle_event(ec_dev);
 	} while (ec_has_more_events);

 	return IRQ_HANDLED;
 }
 EXPORT_SYMBOL(cros_ec_irq_thread);

 static int cros_ec_sleep_event(struct cros_ec_device *ec_dev, u8 sleep_event)
 {
 	int ret;
 	struct {
 		struct cros_ec_command msg;
 		union {
 			struct ec_params_host_sleep_event req0;
 			struct ec_params_host_sleep_event_v1 req1;
 			struct ec_response_host_sleep_event_v1 resp1;
 		} u;
 	} __packed buf;

 	memset(&buf, 0, sizeof(buf));

 	if (ec_dev->host_sleep_v1) {
 		buf.u.req1.sleep_event = sleep_event;
 		buf.u.req1.suspend_params.sleep_timeout_ms =
 				ec_dev->suspend_timeout_ms;

 		buf.msg.outsize = sizeof(buf.u.req1);
 		if ((sleep_event == HOST_SLEEP_EVENT_S3_RESUME) ||
 		    (sleep_event == HOST_SLEEP_EVENT_S0IX_RESUME))
 			buf.msg.insize = sizeof(buf.u.resp1);

 		buf.msg.version = 1;

 	} else {
 		buf.u.req0.sleep_event = sleep_event;
 		buf.msg.outsize = sizeof(buf.u.req0);
 	}

 	buf.msg.command = EC_CMD_HOST_SLEEP_EVENT;

 	ret = cros_ec_cmd_xfer_status(ec_dev, &buf.msg);
 	/* Report failure to transition to system wide suspend with a warning. */
 	if (ret >= 0 && ec_dev->host_sleep_v1 &&
 	    (sleep_event == HOST_SLEEP_EVENT_S0IX_RESUME ||
 	     sleep_event == HOST_SLEEP_EVENT_S3_RESUME)) {
 		ec_dev->last_resume_result =
 			buf.u.resp1.resume_response.sleep_transitions;

 		WARN_ONCE(buf.u.resp1.resume_response.sleep_transitions &
 			  EC_HOST_RESUME_SLEEP_TIMEOUT,
 			  "EC detected sleep transition timeout. Total sleep transitions: %d",
 			  buf.u.resp1.resume_response.sleep_transitions &
 			  EC_HOST_RESUME_SLEEP_TRANSITIONS_MASK);
 	}

 	return ret;
 }

 static int cros_ec_ready_event(struct notifier_block *nb,
 			       unsigned long queued_during_suspend,
 			       void *_notify)
 {
 	struct cros_ec_device *ec_dev = container_of(nb, struct cros_ec_device,
 						     notifier_ready);
 	u32 host_event = cros_ec_get_host_event(ec_dev);

 	if (host_event & EC_HOST_EVENT_MASK(EC_HOST_EVENT_INTERFACE_READY)) {
 		mutex_lock(&ec_dev->lock);
 		cros_ec_query_all(ec_dev);
 		mutex_unlock(&ec_dev->lock);
 		return NOTIFY_OK;
 	}

 	return NOTIFY_DONE;
 }

 /**
  * cros_ec_register() - Register a new ChromeOS EC, using the provided info.
  * @ec_dev: Device to register.
  *
  * Before calling this, allocate a pointer to a new device and then fill
  * in all the fields up to the --private-- marker.
  *
  * Return: 0 on success or negative error code.
  */
 int cros_ec_register(struct cros_ec_device *ec_dev)
 {
 	struct device *dev = ec_dev->dev;
 	int err = 0;

 	BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->event_notifier);
 	BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->panic_notifier);

 	ec_dev->max_request = sizeof(struct ec_params_hello);
 	ec_dev->max_response = sizeof(struct ec_response_get_protocol_info);
 	ec_dev->max_passthru = 0;
 	ec_dev->ec = NULL;
 	ec_dev->pd = NULL;
 	ec_dev->suspend_timeout_ms = EC_HOST_SLEEP_TIMEOUT_DEFAULT;

 	ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
 	if (!ec_dev->din)
 		return -ENOMEM;

 	ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL);
 	if (!ec_dev->dout)
 		return -ENOMEM;

 	lockdep_register_key(&ec_dev->lockdep_key);
 	mutex_init(&ec_dev->lock);
 	lockdep_set_class(&ec_dev->lock, &ec_dev->lockdep_key);

 	err = cros_ec_query_all(ec_dev);
 	if (err) {
 		dev_err(dev, "Cannot identify the EC: error %d\n", err);
 		goto destroy_mutex;
 	}

 	if (ec_dev->irq > 0) {
 		err = devm_request_threaded_irq(dev, ec_dev->irq,
 						cros_ec_irq_handler,
 						cros_ec_irq_thread,
 						IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 						"chromeos-ec", ec_dev);
 		if (err) {
 			dev_err(dev, "Failed to request IRQ %d: %d\n",
 				ec_dev->irq, err);
 			goto destroy_mutex;
 		}
 	}

 	/* Register a platform device for the main EC instance */
 	ec_dev->ec = platform_device_register_data(ec_dev->dev, "cros-ec-dev",
 					PLATFORM_DEVID_AUTO, &ec_p,
 					sizeof(struct cros_ec_platform));
 	if (IS_ERR(ec_dev->ec)) {
 		dev_err(ec_dev->dev,
 			"Failed to create CrOS EC platform device\n");
 		err = PTR_ERR(ec_dev->ec);
 		goto destroy_mutex;
 	}

 	if (ec_dev->max_passthru) {
 		/*
 		 * Register a platform device for the PD behind the main EC.
 		 * We make the following assumptions:
 		 * - behind an EC, we have a pd
 		 * - only one device added.
 		 * - the EC is responsive at init time (it is not true for a
 		 *   sensor hub).
 		 */
 		ec_dev->pd = platform_device_register_data(ec_dev->dev,
 					"cros-ec-dev",
 					PLATFORM_DEVID_AUTO, &pd_p,
 					sizeof(struct cros_ec_platform));
 		if (IS_ERR(ec_dev->pd)) {
 			dev_err(ec_dev->dev,
 				"Failed to create CrOS PD platform device\n");
 			err = PTR_ERR(ec_dev->pd);
 			goto exit;
 		}
 	}

 	if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
 		err = devm_of_platform_populate(dev);
 		if (err) {
 			dev_err(dev, "Failed to register sub-devices\n");
 			goto exit;
 		}
 	}

 	/*
 	 * Clear sleep event - this will fail harmlessly on platforms that
 	 * don't implement the sleep event host command.
 	 */
 	err = cros_ec_sleep_event(ec_dev, 0);
 	if (err < 0)
 		dev_dbg(ec_dev->dev, "Error %d clearing sleep event to ec\n",
 			err);

 	if (ec_dev->mkbp_event_supported) {
 		/*
 		 * Register the notifier for EC_HOST_EVENT_INTERFACE_READY
 		 * event.
 		 */
 		ec_dev->notifier_ready.notifier_call = cros_ec_ready_event;
 		err = blocking_notifier_chain_register(&ec_dev->event_notifier,
 						      &ec_dev->notifier_ready);
 		if (err)
 			goto exit;
 	}

 	dev_info(dev, "Chrome EC device registered\n");

 	/*
 	 * Unlock EC that may be waiting for AP to process MKBP events.
 	 * If the AP takes to long to answer, the EC would stop sending events.
 	 */
 	if (ec_dev->mkbp_event_supported)
 		cros_ec_irq_thread(0, ec_dev);

 	return 0;
 exit:
 	platform_device_unregister(ec_dev->ec);
 	platform_device_unregister(ec_dev->pd);
 destroy_mutex:
 	mutex_destroy(&ec_dev->lock);
 	lockdep_unregister_key(&ec_dev->lockdep_key);
 	return err;
 }
 EXPORT_SYMBOL(cros_ec_register);

 /**
  * cros_ec_unregister() - Remove a ChromeOS EC.
  * @ec_dev: Device to unregister.
  *
  * Call this to deregister a ChromeOS EC, then clean up any private data.
  *
  * Return: 0 on success or negative error code.
  */
 void cros_ec_unregister(struct cros_ec_device *ec_dev)
 {
 	if (ec_dev->pd)
 		platform_device_unregister(ec_dev->pd);
 	platform_device_unregister(ec_dev->ec);
 	mutex_destroy(&ec_dev->lock);
 	lockdep_unregister_key(&ec_dev->lockdep_key);
 }
 EXPORT_SYMBOL(cros_ec_unregister);

 #ifdef CONFIG_PM_SLEEP
 /**
  * cros_ec_suspend() - Handle a suspend operation for the ChromeOS EC device.
  * @ec_dev: Device to suspend.
  *
  * This can be called by drivers to handle a suspend event.
  *
  * Return: 0 on success or negative error code.
  */
 int cros_ec_suspend(struct cros_ec_device *ec_dev)
 {
 	struct device *dev = ec_dev->dev;
 	int ret;
 	u8 sleep_event;

 	sleep_event = (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) ?
 		      HOST_SLEEP_EVENT_S3_SUSPEND :
 		      HOST_SLEEP_EVENT_S0IX_SUSPEND;

 	ret = cros_ec_sleep_event(ec_dev, sleep_event);
 	if (ret < 0)
 		dev_dbg(ec_dev->dev, "Error %d sending suspend event to ec\n",
 			ret);

 	if (device_may_wakeup(dev))
 		ec_dev->wake_enabled = !enable_irq_wake(ec_dev->irq);
 	else
 		ec_dev->wake_enabled = false;

 	disable_irq(ec_dev->irq);
 	ec_dev->suspended = true;

 	return 0;
 }
 EXPORT_SYMBOL(cros_ec_suspend);

 static void cros_ec_report_events_during_suspend(struct cros_ec_device *ec_dev)
 {
 	bool wake_event;

 	while (ec_dev->mkbp_event_supported &&
 	       cros_ec_get_next_event(ec_dev, &wake_event, NULL) > 0) {
 		blocking_notifier_call_chain(&ec_dev->event_notifier,
 					     1, ec_dev);

 		if (wake_event && device_may_wakeup(ec_dev->dev))
 			pm_wakeup_event(ec_dev->dev, 0);
 	}
 }

 /**
  * cros_ec_resume() - Handle a resume operation for the ChromeOS EC device.
  * @ec_dev: Device to resume.
  *
  * This can be called by drivers to handle a resume event.
  *
  * Return: 0 on success or negative error code.
  */
 int cros_ec_resume(struct cros_ec_device *ec_dev)
 {
 	int ret;
 	u8 sleep_event;

 	ec_dev->suspended = false;
 	enable_irq(ec_dev->irq);

 	sleep_event = (!IS_ENABLED(CONFIG_ACPI) || pm_suspend_via_firmware()) ?
 		      HOST_SLEEP_EVENT_S3_RESUME :
 		      HOST_SLEEP_EVENT_S0IX_RESUME;

 	ret = cros_ec_sleep_event(ec_dev, sleep_event);
 	if (ret < 0)
 		dev_dbg(ec_dev->dev, "Error %d sending resume event to ec\n",
 			ret);

 	if (ec_dev->wake_enabled)
 		disable_irq_wake(ec_dev->irq);

 	/*
 	 * Let the mfd devices know about events that occur during
 	 * suspend. This way the clients know what to do with them.
 	 */
 	cros_ec_report_events_during_suspend(ec_dev);


 	return 0;
 }
 EXPORT_SYMBOL(cros_ec_resume);

 #endif

 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("ChromeOS EC core driver");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* ChromeOS EC multi-function device
	*
	* Copyright (C) 2012 Google, Inc
	*
	* The ChromeOS EC multi function device is used to mux all the requests
	* to the EC device for its multiple features: keyboard controller,
	* battery charging and regulator control, firmware update.
	*/

	#include <linux/interrupt.h>
	#include <linux/module.h>
	#include <linux/of_platform.h>
	#include <linux/platform_data/cros_ec_commands.h>
	#include <linux/platform_data/cros_ec_proto.h>
	#include <linux/slab.h>
	#include <linux/suspend.h>

	#include "cros_ec.h"

	static struct cros_ec_platform ec_p = {
	.ec_name = CROS_EC_DEV_NAME,
	.cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_EC_INDEX),
	};

	static struct cros_ec_platform pd_p = {
	.ec_name = CROS_EC_DEV_PD_NAME,
	.cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_PD_INDEX),
	};

	/**
	* cros_ec_irq_handler() - top half part of the interrupt handler
	* @irq: IRQ id
	* @data: (ec_dev) Device with events to process.
	*
	* Return: Wakeup the bottom half
	*/
	static irqreturn_t cros_ec_irq_handler(int irq, void *data)
	{
	struct cros_ec_device *ec_dev = data;

	ec_dev->last_event_time = cros_ec_get_time_ns();

	return IRQ_WAKE_THREAD;
	}

	/**
	* cros_ec_handle_event() - process and forward pending events on EC
	* @ec_dev: Device with events to process.
	*
	* Call this function in a loop when the kernel is notified that the EC has
	* pending events.
	*
	* Return: true if more events are still pending and this function should be
	* called again.
	*/
	static bool cros_ec_handle_event(struct cros_ec_device *ec_dev)
	{
	bool wake_event;
	bool ec_has_more_events;
	int ret;

	ret = cros_ec_get_next_event(ec_dev, &wake_event, &ec_has_more_events);

	/*
	* Signal only if wake host events or any interrupt if
	* cros_ec_get_next_event() returned an error (default value for
	* wake_event is true)
	*/
	if (wake_event && device_may_wakeup(ec_dev->dev))
	pm_wakeup_event(ec_dev->dev, 0);

	if (ret > 0)
	blocking_notifier_call_chain(&ec_dev->event_notifier,
	0, ec_dev);

	return ec_has_more_events;
	}

	/**
	* cros_ec_irq_thread() - bottom half part of the interrupt handler
	* @irq: IRQ id
	* @data: (ec_dev) Device with events to process.
	*
	* Return: Interrupt handled.
	*/
	irqreturn_t cros_ec_irq_thread(int irq, void *data)
	{
	struct cros_ec_device *ec_dev = data;
	bool ec_has_more_events;

	do {
	ec_has_more_events = cros_ec_handle_event(ec_dev);
	} while (ec_has_more_events);

	return IRQ_HANDLED;
	}
	EXPORT_SYMBOL(cros_ec_irq_thread);

	static int cros_ec_sleep_event(struct cros_ec_device *ec_dev, u8 sleep_event)
	{
	int ret;
	struct {
	struct cros_ec_command msg;
	union {
	struct ec_params_host_sleep_event req0;
	struct ec_params_host_sleep_event_v1 req1;
	struct ec_response_host_sleep_event_v1 resp1;
	} u;
	} __packed buf;

	memset(&buf, 0, sizeof(buf));

	if (ec_dev->host_sleep_v1) {
	buf.u.req1.sleep_event = sleep_event;
	buf.u.req1.suspend_params.sleep_timeout_ms =
	ec_dev->suspend_timeout_ms;

	buf.msg.outsize = sizeof(buf.u.req1);
	if ((sleep_event == HOST_SLEEP_EVENT_S3_RESUME) \|\|
	(sleep_event == HOST_SLEEP_EVENT_S0IX_RESUME))
	buf.msg.insize = sizeof(buf.u.resp1);

	buf.msg.version = 1;

	} else {
	buf.u.req0.sleep_event = sleep_event;
	buf.msg.outsize = sizeof(buf.u.req0);
	}

	buf.msg.command = EC_CMD_HOST_SLEEP_EVENT;

	ret = cros_ec_cmd_xfer_status(ec_dev, &buf.msg);
	/* Report failure to transition to system wide suspend with a warning. */
	if (ret >= 0 && ec_dev->host_sleep_v1 &&
	(sleep_event == HOST_SLEEP_EVENT_S0IX_RESUME \|\|
	sleep_event == HOST_SLEEP_EVENT_S3_RESUME)) {
	ec_dev->last_resume_result =
	buf.u.resp1.resume_response.sleep_transitions;

	WARN_ONCE(buf.u.resp1.resume_response.sleep_transitions &
	EC_HOST_RESUME_SLEEP_TIMEOUT,
	"EC detected sleep transition timeout. Total sleep transitions: %d",
	buf.u.resp1.resume_response.sleep_transitions &
	EC_HOST_RESUME_SLEEP_TRANSITIONS_MASK);
	}

	return ret;
	}

	static int cros_ec_ready_event(struct notifier_block *nb,
	unsigned long queued_during_suspend,
	void *_notify)
	{
	struct cros_ec_device *ec_dev = container_of(nb, struct cros_ec_device,
	notifier_ready);
	u32 host_event = cros_ec_get_host_event(ec_dev);

	if (host_event & EC_HOST_EVENT_MASK(EC_HOST_EVENT_INTERFACE_READY)) {
	mutex_lock(&ec_dev->lock);
	cros_ec_query_all(ec_dev);
	mutex_unlock(&ec_dev->lock);
	return NOTIFY_OK;
	}

	return NOTIFY_DONE;
	}

	/**
	* cros_ec_register() - Register a new ChromeOS EC, using the provided info.
	* @ec_dev: Device to register.
	*
	* Before calling this, allocate a pointer to a new device and then fill
	* in all the fields up to the --private-- marker.
	*
	* Return: 0 on success or negative error code.
	*/
	int cros_ec_register(struct cros_ec_device *ec_dev)
	{
	struct device *dev = ec_dev->dev;
	int err = 0;

	BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->event_notifier);
	BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->panic_notifier);

	ec_dev->max_request = sizeof(struct ec_params_hello);
	ec_dev->max_response = sizeof(struct ec_response_get_protocol_info);
	ec_dev->max_passthru = 0;
	ec_dev->ec = NULL;
	ec_dev->pd = NULL;
	ec_dev->suspend_timeout_ms = EC_HOST_SLEEP_TIMEOUT_DEFAULT;

	ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
	if (!ec_dev->din)
	return -ENOMEM;

	ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL);
	if (!ec_dev->dout)
	return -ENOMEM;

	lockdep_register_key(&ec_dev->lockdep_key);
	mutex_init(&ec_dev->lock);
	lockdep_set_class(&ec_dev->lock, &ec_dev->lockdep_key);

	err = cros_ec_query_all(ec_dev);
	if (err) {
	dev_err(dev, "Cannot identify the EC: error %d\n", err);
	goto destroy_mutex;
	}

	if (ec_dev->irq > 0) {
	err = devm_request_threaded_irq(dev, ec_dev->irq,
	cros_ec_irq_handler,
	cros_ec_irq_thread,
	IRQF_TRIGGER_LOW \| IRQF_ONESHOT,
	"chromeos-ec", ec_dev);
	if (err) {
	dev_err(dev, "Failed to request IRQ %d: %d\n",
	ec_dev->irq, err);
	goto destroy_mutex;
	}
	}

	/* Register a platform device for the main EC instance */
	ec_dev->ec = platform_device_register_data(ec_dev->dev, "cros-ec-dev",
	PLATFORM_DEVID_AUTO, &ec_p,
	sizeof(struct cros_ec_platform));
	if (IS_ERR(ec_dev->ec)) {
	dev_err(ec_dev->dev,
	"Failed to create CrOS EC platform device\n");
	err = PTR_ERR(ec_dev->ec);
	goto destroy_mutex;
	}

	if (ec_dev->max_passthru) {
	/*
	* Register a platform device for the PD behind the main EC.
	* We make the following assumptions:
	* - behind an EC, we have a pd
	* - only one device added.
	* - the EC is responsive at init time (it is not true for a
	* sensor hub).
	*/
	ec_dev->pd = platform_device_register_data(ec_dev->dev,
	"cros-ec-dev",
	PLATFORM_DEVID_AUTO, &pd_p,
	sizeof(struct cros_ec_platform));
	if (IS_ERR(ec_dev->pd)) {
	dev_err(ec_dev->dev,
	"Failed to create CrOS PD platform device\n");
	err = PTR_ERR(ec_dev->pd);
	goto exit;
	}
	}

	if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
	err = devm_of_platform_populate(dev);
	if (err) {
	dev_err(dev, "Failed to register sub-devices\n");
	goto exit;
	}
	}

	/*
	* Clear sleep event - this will fail harmlessly on platforms that
	* don't implement the sleep event host command.
	*/
	err = cros_ec_sleep_event(ec_dev, 0);
	if (err < 0)
	dev_dbg(ec_dev->dev, "Error %d clearing sleep event to ec\n",
	err);

	if (ec_dev->mkbp_event_supported) {
	/*
	* Register the notifier for EC_HOST_EVENT_INTERFACE_READY
	* event.
	*/
	ec_dev->notifier_ready.notifier_call = cros_ec_ready_event;
	err = blocking_notifier_chain_register(&ec_dev->event_notifier,
	&ec_dev->notifier_ready);
	if (err)
	goto exit;
	}

	dev_info(dev, "Chrome EC device registered\n");

	/*
	* Unlock EC that may be waiting for AP to process MKBP events.
	* If the AP takes to long to answer, the EC would stop sending events.
	*/
	if (ec_dev->mkbp_event_supported)
	cros_ec_irq_thread(0, ec_dev);

	return 0;
	exit:
	platform_device_unregister(ec_dev->ec);
	platform_device_unregister(ec_dev->pd);
	destroy_mutex:
	mutex_destroy(&ec_dev->lock);
	lockdep_unregister_key(&ec_dev->lockdep_key);
	return err;
	}
	EXPORT_SYMBOL(cros_ec_register);

	/**
	* cros_ec_unregister() - Remove a ChromeOS EC.
	* @ec_dev: Device to unregister.
	*
	* Call this to deregister a ChromeOS EC, then clean up any private data.
	*
	* Return: 0 on success or negative error code.
	*/
	void cros_ec_unregister(struct cros_ec_device *ec_dev)
	{
	if (ec_dev->pd)
	platform_device_unregister(ec_dev->pd);
	platform_device_unregister(ec_dev->ec);
	mutex_destroy(&ec_dev->lock);
	lockdep_unregister_key(&ec_dev->lockdep_key);
	}
	EXPORT_SYMBOL(cros_ec_unregister);

	#ifdef CONFIG_PM_SLEEP
	/**
	* cros_ec_suspend() - Handle a suspend operation for the ChromeOS EC device.
	* @ec_dev: Device to suspend.
	*
	* This can be called by drivers to handle a suspend event.
	*
	* Return: 0 on success or negative error code.
	*/
	int cros_ec_suspend(struct cros_ec_device *ec_dev)
	{
	struct device *dev = ec_dev->dev;
	int ret;
	u8 sleep_event;

	sleep_event = (!IS_ENABLED(CONFIG_ACPI) \|\| pm_suspend_via_firmware()) ?
	HOST_SLEEP_EVENT_S3_SUSPEND :
	HOST_SLEEP_EVENT_S0IX_SUSPEND;

	ret = cros_ec_sleep_event(ec_dev, sleep_event);
	if (ret < 0)
	dev_dbg(ec_dev->dev, "Error %d sending suspend event to ec\n",
	ret);

	if (device_may_wakeup(dev))
	ec_dev->wake_enabled = !enable_irq_wake(ec_dev->irq);
	else
	ec_dev->wake_enabled = false;

	disable_irq(ec_dev->irq);
	ec_dev->suspended = true;

	return 0;
	}
	EXPORT_SYMBOL(cros_ec_suspend);

	static void cros_ec_report_events_during_suspend(struct cros_ec_device *ec_dev)
	{
	bool wake_event;

	while (ec_dev->mkbp_event_supported &&
	cros_ec_get_next_event(ec_dev, &wake_event, NULL) > 0) {
	blocking_notifier_call_chain(&ec_dev->event_notifier,
	1, ec_dev);

	if (wake_event && device_may_wakeup(ec_dev->dev))
	pm_wakeup_event(ec_dev->dev, 0);
	}
	}

	/**
	* cros_ec_resume() - Handle a resume operation for the ChromeOS EC device.
	* @ec_dev: Device to resume.
	*
	* This can be called by drivers to handle a resume event.
	*
	* Return: 0 on success or negative error code.
	*/
	int cros_ec_resume(struct cros_ec_device *ec_dev)
	{
	int ret;
	u8 sleep_event;

	ec_dev->suspended = false;
	enable_irq(ec_dev->irq);

	sleep_event = (!IS_ENABLED(CONFIG_ACPI) \|\| pm_suspend_via_firmware()) ?
	HOST_SLEEP_EVENT_S3_RESUME :
	HOST_SLEEP_EVENT_S0IX_RESUME;

	ret = cros_ec_sleep_event(ec_dev, sleep_event);
	if (ret < 0)
	dev_dbg(ec_dev->dev, "Error %d sending resume event to ec\n",
	ret);

	if (ec_dev->wake_enabled)
	disable_irq_wake(ec_dev->irq);

	/*
	* Let the mfd devices know about events that occur during
	* suspend. This way the clients know what to do with them.
	*/
	cros_ec_report_events_during_suspend(ec_dev);


	return 0;
	}
	EXPORT_SYMBOL(cros_ec_resume);

	#endif

	MODULE_LICENSE("GPL");
	MODULE_DESCRIPTION("ChromeOS EC core driver");