Release 4.17 drivers/acpi/acpi_tad.c

Directory: drivers/acpi
// SPDX-License-Identifier: GPL-2.0
/*
 * ACPI Time and Alarm (TAD) Device Driver
 *
 * Copyright (C) 2018 Intel Corporation
 * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
 *
 * This driver is based on Section 9.18 of the ACPI 6.2 specification revision.
 *
 * It only supports the system wakeup capabilities of the TAD.
 *
 * Provided are sysfs attributes, available under the TAD platform device,
 * allowing user space to manage the AC and DC wakeup timers of the TAD:
 * set and read their values, set and check their expire timer wake policies,
 * check and clear their status and check the capabilities of the TAD reported
 * by AML.  The DC timer attributes are only present if the TAD supports a
 * separate DC alarm timer.
 *
 * The wakeup events handling and power management of the TAD is expected to
 * be taken care of by the ACPI PM domain attached to its platform device.
 */

#include <linux/acpi.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/suspend.h>

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Rafael J. Wysocki");

/* ACPI TAD capability flags (ACPI 6.2, Section 9.18.2) */

#define ACPI_TAD_AC_WAKE	BIT(0)

#define ACPI_TAD_DC_WAKE	BIT(1)

#define ACPI_TAD_RT		BIT(2)

#define ACPI_TAD_RT_IN_MS	BIT(3)

#define ACPI_TAD_S4_S5__GWS	BIT(4)

#define ACPI_TAD_AC_S4_WAKE	BIT(5)

#define ACPI_TAD_AC_S5_WAKE	BIT(6)

#define ACPI_TAD_DC_S4_WAKE	BIT(7)

#define ACPI_TAD_DC_S5_WAKE	BIT(8)

/* ACPI TAD alarm timer selection */

#define ACPI_TAD_AC_TIMER	(u32)0

#define ACPI_TAD_DC_TIMER	(u32)1

/* Special value for disabled timer or expired timer wake policy. */

#define ACPI_TAD_WAKE_DISABLED	(~(u32)0)


struct acpi_tad_driver_data {
	
u32 capabilities;
};



static int acpi_tad_wake_set(struct device *dev, char *method, u32 timer_id,
			     u32 value)
{
	acpi_handle handle = ACPI_HANDLE(dev);
	union acpi_object args[] = {
		{ .type = ACPI_TYPE_INTEGER, },
		{ .type = ACPI_TYPE_INTEGER, },
        };
	struct acpi_object_list arg_list = {
		.pointer = args,
		.count = ARRAY_SIZE(args),
        };
	unsigned long long retval;
	acpi_status status;

	args[0].integer.value = timer_id;
	args[1].integer.value = value;

	pm_runtime_get_sync(dev);

	status = acpi_evaluate_integer(handle, method, &arg_list, &retval);

	pm_runtime_put_sync(dev);

	if (ACPI_FAILURE(status) || retval)
		return -EIO;

	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
Rafael J. Wysocki 140 100.00% 1 100.00%
Total 140 100.00% 1 100.00%



static int acpi_tad_wake_write(struct device *dev, const char *buf, char *method,
			       u32 timer_id, const char *specval)
{
	u32 value;

	if (sysfs_streq(buf, specval)) {
		value = ACPI_TAD_WAKE_DISABLED;
	} else {
		int ret = kstrtou32(buf, 0, &value);

		if (ret)
			return ret;

		if (value == ACPI_TAD_WAKE_DISABLED)
			return -EINVAL;
	}

	return acpi_tad_wake_set(dev, method, timer_id, value);
}

Contributors
Person Tokens Prop Commits CommitProp
Rafael J. Wysocki 91 100.00% 1 100.00%
Total 91 100.00% 1 100.00%



static ssize_t acpi_tad_wake_read(struct device *dev, char *buf, char *method,
				  u32 timer_id, const char *specval)
{
	acpi_handle handle = ACPI_HANDLE(dev);
	union acpi_object args[] = {
		{ .type = ACPI_TYPE_INTEGER, },
        };
	struct acpi_object_list arg_list = {
		.pointer = args,
		.count = ARRAY_SIZE(args),
        };
	unsigned long long retval;
	acpi_status status;

	args[0].integer.value = timer_id;

	pm_runtime_get_sync(dev);

	status = acpi_evaluate_integer(handle, method, &arg_list, &retval);

	pm_runtime_put_sync(dev);

	if (ACPI_FAILURE(status))
		return -EIO;

	if ((u32)retval == ACPI_TAD_WAKE_DISABLED)
		return sprintf(buf, "%s\n", specval);

	return sprintf(buf, "%u\n", (u32)retval);
}

Contributors
Person Tokens Prop Commits CommitProp
Rafael J. Wysocki 155 100.00% 1 100.00%
Total 155 100.00% 1 100.00%


static const char *alarm_specval = "disabled";



static int acpi_tad_alarm_write(struct device *dev, const char *buf,
				u32 timer_id)
{
	return acpi_tad_wake_write(dev, buf, "_STV", timer_id, alarm_specval);
}

Contributors
Person Tokens Prop Commits CommitProp
Rafael J. Wysocki 33 100.00% 1 100.00%
Total 33 100.00% 1 100.00%



static ssize_t acpi_tad_alarm_read(struct device *dev, char *buf, u32 timer_id)
{
	return acpi_tad_wake_read(dev, buf, "_TIV", timer_id, alarm_specval);
}

Contributors
Person Tokens Prop Commits CommitProp
Rafael J. Wysocki 32 100.00% 1 100.00%
Total 32 100.00% 1 100.00%


static const char *policy_specval = "never";



static int acpi_tad_policy_write(struct device *dev, const char *buf,
				 u32 timer_id)
{
	return acpi_tad_wake_write(dev, buf, "_STP", timer_id, policy_specval);
}

Contributors
Person Tokens Prop Commits CommitProp
Rafael J. Wysocki 33 100.00% 1 100.00%
Total 33 100.00% 1 100.00%



static ssize_t acpi_tad_policy_read(struct device *dev, char *buf, u32 timer_id)
{
	return acpi_tad_wake_read(dev, buf, "_TIP", timer_id, policy_specval);
}

Contributors
Person Tokens Prop Commits CommitProp
Rafael J. Wysocki 32 100.00% 1 100.00%
Total 32 100.00% 1 100.00%



static int acpi_tad_clear_status(struct device *dev, u32 timer_id)
{
	acpi_handle handle = ACPI_HANDLE(dev);
	union acpi_object args[] = {
		{ .type = ACPI_TYPE_INTEGER, },
        };
	struct acpi_object_list arg_list = {
		.pointer = args,
		.count = ARRAY_SIZE(args),
        };
	unsigned long long retval;
	acpi_status status;

	args[0].integer.value = timer_id;

	pm_runtime_get_sync(dev);

	status = acpi_evaluate_integer(handle, "_CWS", &arg_list, &retval);

	pm_runtime_put_sync(dev);

	if (ACPI_FAILURE(status) || retval)
		return -EIO;

	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
Rafael J. Wysocki 115 100.00% 1 100.00%
Total 115 100.00% 1 100.00%



static int acpi_tad_status_write(struct device *dev, const char *buf, u32 timer_id)
{
	int ret, value;

	ret = kstrtoint(buf, 0, &value);
	if (ret)
		return ret;

	if (value)
		return -EINVAL;

	return acpi_tad_clear_status(dev, timer_id);
}

Contributors
Person Tokens Prop Commits CommitProp
Rafael J. Wysocki 59 100.00% 1 100.00%
Total 59 100.00% 1 100.00%



static ssize_t acpi_tad_status_read(struct device *dev, char *buf, u32 timer_id)
{
	acpi_handle handle = ACPI_HANDLE(dev);
	union acpi_object args[] = {
		{ .type = ACPI_TYPE_INTEGER, },
        };
	struct acpi_object_list arg_list = {
		.pointer = args,
		.count = ARRAY_SIZE(args),
        };
	unsigned long long retval;
	acpi_status status;

	args[0].integer.value = timer_id;

	pm_runtime_get_sync(dev);

	status = acpi_evaluate_integer(handle, "_GWS", &arg_list, &retval);

	pm_runtime_put_sync(dev);

	if (ACPI_FAILURE(status))
		return -EIO;

	return sprintf(buf, "0x%02X\n", (u32)retval);
}

Contributors
Person Tokens Prop Commits CommitProp
Rafael J. Wysocki 127 100.00% 1 100.00%
Total 127 100.00% 1 100.00%



static ssize_t caps_show(struct device *dev, struct device_attribute *attr,
			 char *buf)
{
	struct acpi_tad_driver_data *dd = dev_get_drvdata(dev);

	return sprintf(buf, "0x%02X\n", dd->capabilities);
}

Contributors
Person Tokens Prop Commits CommitProp
Rafael J. Wysocki 42 100.00% 1 100.00%
Total 42 100.00% 1 100.00%

static DEVICE_ATTR_RO(caps);



static ssize_t ac_alarm_store(struct device *dev, struct device_attribute *attr,
			      const char *buf, size_t count)
{
	int ret = acpi_tad_alarm_write(dev, buf, ACPI_TAD_AC_TIMER);

	return ret ? ret : count;
}

Contributors
Person Tokens Prop Commits CommitProp
Rafael J. Wysocki 43 100.00% 1 100.00%
Total 43 100.00% 1 100.00%



static ssize_t ac_alarm_show(struct device *dev, struct device_attribute *attr,
			     char *buf)
{
	return acpi_tad_alarm_read(dev, buf, ACPI_TAD_AC_TIMER);
}

Contributors
Person Tokens Prop Commits CommitProp
Rafael J. Wysocki 30 100.00% 1 100.00%
Total 30 100.00% 1 100.00%

static DEVICE_ATTR(ac_alarm, S_IRUSR | S_IWUSR, ac_alarm_show, ac_alarm_store);



static ssize_t ac_policy_store(struct device *dev, struct device_attribute *attr,
			       const char *buf, size_t count)
{
	int ret = acpi_tad_policy_write(dev, buf, ACPI_TAD_AC_TIMER);

	return ret ? ret : count;
}

Contributors
Person Tokens Prop Commits CommitProp
Rafael J. Wysocki 43 100.00% 1 100.00%
Total 43 100.00% 1 100.00%



static ssize_t ac_policy_show(struct device *dev, struct device_attribute *attr,
			      char *buf)
{
	return acpi_tad_policy_read(dev, buf, ACPI_TAD_AC_TIMER);
}

Contributors
Person Tokens Prop Commits CommitProp
Rafael J. Wysocki 30 100.00% 1 100.00%
Total 30 100.00% 1 100.00%

static DEVICE_ATTR(ac_policy, S_IRUSR | S_IWUSR, ac_policy_show, ac_policy_store);



static ssize_t ac_status_store(struct device *dev, struct device_attribute *attr,
			       const char *buf, size_t count)
{
	int ret = acpi_tad_status_write(dev, buf, ACPI_TAD_AC_TIMER);

	return ret ? ret : count;
}

Contributors
Person Tokens Prop Commits CommitProp
Rafael J. Wysocki 43 100.00% 1 100.00%
Total 43 100.00% 1 100.00%



static ssize_t ac_status_show(struct device *dev, struct device_attribute *attr,
			      char *buf)
{
	return acpi_tad_status_read(dev, buf, ACPI_TAD_AC_TIMER);
}

Contributors
Person Tokens Prop Commits CommitProp
Rafael J. Wysocki 30 100.00% 1 100.00%
Total 30 100.00% 1 100.00%

static DEVICE_ATTR(ac_status, S_IRUSR | S_IWUSR, ac_status_show, ac_status_store);


static struct attribute *acpi_tad_attrs[] = {
	&dev_attr_caps.attr,
	&dev_attr_ac_alarm.attr,
	&dev_attr_ac_policy.attr,
	&dev_attr_ac_status.attr,
	NULL,
};

static const struct attribute_group acpi_tad_attr_group = {
	.attrs	= acpi_tad_attrs,
};



static ssize_t dc_alarm_store(struct device *dev, struct device_attribute *attr,
			      const char *buf, size_t count)
{
	int ret = acpi_tad_alarm_write(dev, buf, ACPI_TAD_DC_TIMER);

	return ret ? ret : count;
}

Contributors
Person Tokens Prop Commits CommitProp
Rafael J. Wysocki 43 100.00% 1 100.00%
Total 43 100.00% 1 100.00%



static ssize_t dc_alarm_show(struct device *dev, struct device_attribute *attr,
			     char *buf)
{
	return acpi_tad_alarm_read(dev, buf, ACPI_TAD_DC_TIMER);
}

Contributors
Person Tokens Prop Commits CommitProp
Rafael J. Wysocki 30 100.00% 1 100.00%
Total 30 100.00% 1 100.00%

static DEVICE_ATTR(dc_alarm, S_IRUSR | S_IWUSR, dc_alarm_show, dc_alarm_store);



static ssize_t dc_policy_store(struct device *dev, struct device_attribute *attr,
			       const char *buf, size_t count)
{
	int ret = acpi_tad_policy_write(dev, buf, ACPI_TAD_DC_TIMER);

	return ret ? ret : count;
}

Contributors
Person Tokens Prop Commits CommitProp
Rafael J. Wysocki 43 100.00% 1 100.00%
Total 43 100.00% 1 100.00%



static ssize_t dc_policy_show(struct device *dev, struct device_attribute *attr,
			      char *buf)
{
	return acpi_tad_policy_read(dev, buf, ACPI_TAD_DC_TIMER);
}

Contributors
Person Tokens Prop Commits CommitProp
Rafael J. Wysocki 30 100.00% 1 100.00%
Total 30 100.00% 1 100.00%

static DEVICE_ATTR(dc_policy, S_IRUSR | S_IWUSR, dc_policy_show, dc_policy_store);



static ssize_t dc_status_store(struct device *dev, struct device_attribute *attr,
			       const char *buf, size_t count)
{
	int ret = acpi_tad_status_write(dev, buf, ACPI_TAD_DC_TIMER);

	return ret ? ret : count;
}

Contributors
Person Tokens Prop Commits CommitProp
Rafael J. Wysocki 43 100.00% 1 100.00%
Total 43 100.00% 1 100.00%



static ssize_t dc_status_show(struct device *dev, struct device_attribute *attr,
			      char *buf)
{
	return acpi_tad_status_read(dev, buf, ACPI_TAD_DC_TIMER);
}

Contributors
Person Tokens Prop Commits CommitProp
Rafael J. Wysocki 30 100.00% 1 100.00%
Total 30 100.00% 1 100.00%

static DEVICE_ATTR(dc_status, S_IRUSR | S_IWUSR, dc_status_show, dc_status_store);


static struct attribute *acpi_tad_dc_attrs[] = {
	&dev_attr_dc_alarm.attr,
	&dev_attr_dc_policy.attr,
	&dev_attr_dc_status.attr,
	NULL,
};

static const struct attribute_group acpi_tad_dc_attr_group = {
	.attrs	= acpi_tad_dc_attrs,
};



static int acpi_tad_disable_timer(struct device *dev, u32 timer_id)
{
	return acpi_tad_wake_set(dev, "_STV", timer_id, ACPI_TAD_WAKE_DISABLED);
}

Contributors
Person Tokens Prop Commits CommitProp
Rafael J. Wysocki 26 100.00% 1 100.00%
Total 26 100.00% 1 100.00%



static int acpi_tad_remove(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct acpi_tad_driver_data *dd = dev_get_drvdata(dev);

	device_init_wakeup(dev, false);

	pm_runtime_get_sync(dev);

	if (dd->capabilities & ACPI_TAD_DC_WAKE)
		sysfs_remove_group(&dev->kobj, &acpi_tad_dc_attr_group);

	sysfs_remove_group(&dev->kobj, &acpi_tad_attr_group);

	acpi_tad_disable_timer(dev, ACPI_TAD_AC_TIMER);
	acpi_tad_clear_status(dev, ACPI_TAD_AC_TIMER);
	if (dd->capabilities & ACPI_TAD_DC_WAKE) {
		acpi_tad_disable_timer(dev, ACPI_TAD_DC_TIMER);
		acpi_tad_clear_status(dev, ACPI_TAD_DC_TIMER);
	}

	pm_runtime_put_sync(dev);
	pm_runtime_disable(dev);
	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
Rafael J. Wysocki 124 100.00% 1 100.00%
Total 124 100.00% 1 100.00%



static int acpi_tad_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	acpi_handle handle = ACPI_HANDLE(dev);
	struct acpi_tad_driver_data *dd;
	acpi_status status;
	unsigned long long caps;
	int ret;

	/*
         * Initialization failure messages are mostly about firmware issues, so
         * print them at the "info" level.
         */
	status = acpi_evaluate_integer(handle, "_GCP", NULL, &caps);
	if (ACPI_FAILURE(status)) {
		dev_info(dev, "Unable to get capabilities\n");
		return -ENODEV;
	}

	if (!(caps & ACPI_TAD_AC_WAKE)) {
		dev_info(dev, "Unsupported capabilities\n");
		return -ENODEV;
	}

	if (!acpi_has_method(handle, "_PRW")) {
		dev_info(dev, "Missing _PRW\n");
		return -ENODEV;
	}

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

	dd->capabilities = caps;
	dev_set_drvdata(dev, dd);

	/*
         * Assume that the ACPI PM domain has been attached to the device and
         * simply enable system wakeup and runtime PM and put the device into
         * runtime suspend.  Everything else should be taken care of by the ACPI
         * PM domain callbacks.
         */
	device_init_wakeup(dev, true);
	dev_pm_set_driver_flags(dev, DPM_FLAG_SMART_SUSPEND |
				     DPM_FLAG_LEAVE_SUSPENDED);
	/*
         * The platform bus type layer tells the ACPI PM domain powers up the
         * device, so set the runtime PM status of it to "active".
         */
	pm_runtime_set_active(dev);
	pm_runtime_enable(dev);
	pm_runtime_suspend(dev);

	ret = sysfs_create_group(&dev->kobj, &acpi_tad_attr_group);
	if (ret)
		goto fail;

	if (caps & ACPI_TAD_DC_WAKE) {
		ret = sysfs_create_group(&dev->kobj, &acpi_tad_dc_attr_group);
		if (ret)
			goto fail;
	}

	return 0;

fail:
	acpi_tad_remove(pdev);
	return ret;
}

Contributors
Person Tokens Prop Commits CommitProp
Rafael J. Wysocki 256 100.00% 1 100.00%
Total 256 100.00% 1 100.00%


static const struct acpi_device_id acpi_tad_ids[] = {
	{"ACPI000E", 0},
	{}
};


static struct platform_driver acpi_tad_driver = {
	.driver = {
		.name = "acpi-tad",
		.acpi_match_table = acpi_tad_ids,
        },
	.probe = acpi_tad_probe,
	.remove = acpi_tad_remove,
};
MODULE_DEVICE_TABLE(acpi, acpi_tad_ids);

module_platform_driver(acpi_tad_driver);
Overall Contributors
Person Tokens Prop Commits CommitProp
Rafael J. Wysocki 2042 100.00% 1 100.00%
Total 2042 100.00% 1 100.00%
Directory: drivers/acpi

Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with cregit.
Person	Tokens	Prop	Commits	CommitProp
Rafael J. Wysocki	140	100.00%	1	100.00%
Total	140	100.00%	1	100.00%
cregit-Linux how code gets into the kernel

Release 4.17 drivers/acpi/acpi_tad.c

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Overall Contributors
