drivers/mfd/cros_ec.c - linux - Git at Google

 /*
  * ChromeOS EC multi-function device
  *
  * Copyright (C) 2012 Google, Inc
  *
  * This software is licensed under the terms of the GNU General Public
  * License version 2, as published by the Free Software Foundation, and
  * may be copied, distributed, and modified under those terms.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * 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/of_platform.h>
 #include <linux/interrupt.h>
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/mfd/core.h>
 #include <linux/mfd/cros_ec.h>
 #include <linux/suspend.h>
 #include <asm/unaligned.h>

 #define CROS_EC_DEV_EC_INDEX 0
 #define CROS_EC_DEV_PD_INDEX 1

 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),
 };

 static const struct mfd_cell ec_cell = {
 	.name = "cros-ec-dev",
 	.platform_data = &ec_p,
 	.pdata_size = sizeof(ec_p),
 };

 static const struct mfd_cell ec_pd_cell = {
 	.name = "cros-ec-dev",
 	.platform_data = &pd_p,
 	.pdata_size = sizeof(pd_p),
 };

 static irqreturn_t ec_irq_thread(int irq, void *data)
 {
 	struct cros_ec_device *ec_dev = data;
 	bool wake_event = true;
 	int ret;

 	ret = cros_ec_get_next_event(ec_dev, &wake_event);

 	/*
 	 * 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 IRQ_HANDLED;
 }

 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_HOST_SLEEP_TIMEOUT_DEFAULT;

 		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(ec_dev, &buf.msg);

 	/* For now, report failure to transition to S0ix with a warning. */
 	if (ret >= 0 && ec_dev->host_sleep_v1 &&
 	    (sleep_event == HOST_SLEEP_EVENT_S0IX_RESUME))
 		WARN_ONCE(buf.u.resp1.resume_response.sleep_transitions &
 			  EC_HOST_RESUME_SLEEP_TIMEOUT,
 			  "EC detected sleep transition timeout. Total slp_s0 transitions: %d",
 			  buf.u.resp1.resume_response.sleep_transitions &
 			  EC_HOST_RESUME_SLEEP_TRANSITIONS_MASK);

 	return ret;
 }

 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);

 	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->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;

 	mutex_init(&ec_dev->lock);

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

 	if (ec_dev->irq) {
 		err = devm_request_threaded_irq(dev, ec_dev->irq, NULL,
 				ec_irq_thread, IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 				"chromeos-ec", ec_dev);
 		if (err) {
 			dev_err(dev, "Failed to request IRQ %d: %d",
 				ec_dev->irq, err);
 			return err;
 		}
 	}

 	err = devm_mfd_add_devices(ec_dev->dev, PLATFORM_DEVID_AUTO, &ec_cell,
 				   1, NULL, ec_dev->irq, NULL);
 	if (err) {
 		dev_err(dev,
 			"Failed to register Embedded Controller subdevice %d\n",
 			err);
 		return err;
 	}

 	if (ec_dev->max_passthru) {
 		/*
 		 * Register a PD device as well on top of this device.
 		 * 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.
 		 */
 		err = devm_mfd_add_devices(ec_dev->dev, PLATFORM_DEVID_AUTO,
 				      &ec_pd_cell, 1, NULL, ec_dev->irq, NULL);
 		if (err) {
 			dev_err(dev,
 				"Failed to register Power Delivery subdevice %d\n",
 				err);
 			return err;
 		}
 	}

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

 	/*
 	 * 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",
 			err);

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

 	return 0;
 }
 EXPORT_SYMBOL(cros_ec_register);

 #ifdef CONFIG_PM_SLEEP
 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",
 			ret);

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

 	disable_irq(ec_dev->irq);
 	ec_dev->was_wake_device = ec_dev->wake_enabled;
 	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)
 {
 	while (ec_dev->mkbp_event_supported &&
 	       cros_ec_get_next_event(ec_dev, NULL) > 0)
 		blocking_notifier_call_chain(&ec_dev->event_notifier,
 					     1, ec_dev);
 }

 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",
 			ret);

 	if (ec_dev->wake_enabled) {
 		disable_irq_wake(ec_dev->irq);
 		ec_dev->wake_enabled = 0;
 	}
 	/*
 	 * 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");
	/*
	* ChromeOS EC multi-function device
	*
	* Copyright (C) 2012 Google, Inc
	*
	* This software is licensed under the terms of the GNU General Public
	* License version 2, as published by the Free Software Foundation, and
	* may be copied, distributed, and modified under those terms.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* 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/of_platform.h>
	#include <linux/interrupt.h>
	#include <linux/slab.h>
	#include <linux/module.h>
	#include <linux/mfd/core.h>
	#include <linux/mfd/cros_ec.h>
	#include <linux/suspend.h>
	#include <asm/unaligned.h>

	#define CROS_EC_DEV_EC_INDEX 0
	#define CROS_EC_DEV_PD_INDEX 1

	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),
	};

	static const struct mfd_cell ec_cell = {
	.name = "cros-ec-dev",
	.platform_data = &ec_p,
	.pdata_size = sizeof(ec_p),
	};

	static const struct mfd_cell ec_pd_cell = {
	.name = "cros-ec-dev",
	.platform_data = &pd_p,
	.pdata_size = sizeof(pd_p),
	};

	static irqreturn_t ec_irq_thread(int irq, void *data)
	{
	struct cros_ec_device *ec_dev = data;
	bool wake_event = true;
	int ret;

	ret = cros_ec_get_next_event(ec_dev, &wake_event);

	/*
	* 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 IRQ_HANDLED;
	}

	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_HOST_SLEEP_TIMEOUT_DEFAULT;

	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(ec_dev, &buf.msg);

	/* For now, report failure to transition to S0ix with a warning. */
	if (ret >= 0 && ec_dev->host_sleep_v1 &&
	(sleep_event == HOST_SLEEP_EVENT_S0IX_RESUME))
	WARN_ONCE(buf.u.resp1.resume_response.sleep_transitions &
	EC_HOST_RESUME_SLEEP_TIMEOUT,
	"EC detected sleep transition timeout. Total slp_s0 transitions: %d",
	buf.u.resp1.resume_response.sleep_transitions &
	EC_HOST_RESUME_SLEEP_TRANSITIONS_MASK);

	return ret;
	}

	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);

	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->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;

	mutex_init(&ec_dev->lock);

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

	if (ec_dev->irq) {
	err = devm_request_threaded_irq(dev, ec_dev->irq, NULL,
	ec_irq_thread, IRQF_TRIGGER_LOW \| IRQF_ONESHOT,
	"chromeos-ec", ec_dev);
	if (err) {
	dev_err(dev, "Failed to request IRQ %d: %d",
	ec_dev->irq, err);
	return err;
	}
	}

	err = devm_mfd_add_devices(ec_dev->dev, PLATFORM_DEVID_AUTO, &ec_cell,
	1, NULL, ec_dev->irq, NULL);
	if (err) {
	dev_err(dev,
	"Failed to register Embedded Controller subdevice %d\n",
	err);
	return err;
	}

	if (ec_dev->max_passthru) {
	/*
	* Register a PD device as well on top of this device.
	* 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.
	*/
	err = devm_mfd_add_devices(ec_dev->dev, PLATFORM_DEVID_AUTO,
	&ec_pd_cell, 1, NULL, ec_dev->irq, NULL);
	if (err) {
	dev_err(dev,
	"Failed to register Power Delivery subdevice %d\n",
	err);
	return err;
	}
	}

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

	/*
	* 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",
	err);

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

	return 0;
	}
	EXPORT_SYMBOL(cros_ec_register);

	#ifdef CONFIG_PM_SLEEP
	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",
	ret);

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

	disable_irq(ec_dev->irq);
	ec_dev->was_wake_device = ec_dev->wake_enabled;
	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)
	{
	while (ec_dev->mkbp_event_supported &&
	cros_ec_get_next_event(ec_dev, NULL) > 0)
	blocking_notifier_call_chain(&ec_dev->event_notifier,
	1, ec_dev);
	}

	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",
	ret);

	if (ec_dev->wake_enabled) {
	disable_irq_wake(ec_dev->irq);
	ec_dev->wake_enabled = 0;
	}
	/*
	* 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");