// SPDX-License-Identifier: GPL-2.0
/*
* ACPI Time and Alarm (TAD) Device Driver
*
* Copyright (C) 2018 Intel Corporation
* Author: Rafael J. Wysocki <[email protected]>
*
* 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_DESCRIPTION("ACPI Time and Alarm (TAD) Device Driver");
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;
};
struct acpi_tad_rt {
u16 year; /* 1900 - 9999 */
u8 month; /* 1 - 12 */
u8 day; /* 1 - 31 */
u8 hour; /* 0 - 23 */
u8 minute; /* 0 - 59 */
u8 second; /* 0 - 59 */
u8 valid; /* 0 (failed) or 1 (success) for reads, 0 for writes */
u16 msec; /* 1 - 1000 */
s16 tz; /* -1440 to 1440 or 2047 (unspecified) */
u8 daylight;
u8 padding[3]; /* must be 0 */
} __packed;
static int acpi_tad_set_real_time(struct device *dev, struct acpi_tad_rt *rt)
{
acpi_handle handle = ACPI_HANDLE(dev);
union acpi_object args[] = {
{ .type = ACPI_TYPE_BUFFER, },
};
struct acpi_object_list arg_list = {
.pointer = args,
.count = ARRAY_SIZE(args),
};
unsigned long long retval;
acpi_status status;
if (rt->year < 1900 || rt->year > 9999 ||
rt->month < 1 || rt->month > 12 ||
rt->hour > 23 || rt->minute > 59 || rt->second > 59 ||
rt->tz < -1440 || (rt->tz > 1440 && rt->tz != 2047) ||
rt->daylight > 3)
return -ERANGE;
args[0].buffer.pointer = (u8 *)rt;
args[0].buffer.length = sizeof(*rt);
pm_runtime_get_sync(dev);
status = acpi_evaluate_integer(handle, "_SRT", &arg_list, &retval);
pm_runtime_put_sync(dev);
if (ACPI_FAILURE(status) || retval)
return -EIO;
return 0;
}
static int acpi_tad_get_real_time(struct device *dev, struct acpi_tad_rt *rt)
{
acpi_handle handle = ACPI_HANDLE(dev);
struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER };
union acpi_object *out_obj;
struct acpi_tad_rt *data;
acpi_status status;
int ret = -EIO;
pm_runtime_get_sync(dev);
status = acpi_evaluate_object(handle, "_GRT", NULL, &output);
pm_runtime_put_sync(dev);
if (ACPI_FAILURE(status))
goto out_free;
out_obj = output.pointer;
if (out_obj->type != ACPI_TYPE_BUFFER)
goto out_free;
if (out_obj->buffer.length != sizeof(*rt))
goto out_free;
data = (struct acpi_tad_rt *)(out_obj->buffer.pointer);
if (!data->valid)
goto out_free;
memcpy(rt, data, sizeof(*rt));
ret = 0;
out_free:
ACPI_FREE(output.pointer);
return ret;
}
static char *acpi_tad_rt_next_field(char *s, int *val)
{
char *p;
p = strchr(s, ':');
if (!p)
return NULL;
*p = '\0';
if (kstrtoint(s, 10, val))
return NULL;
return p + 1;
}
static ssize_t time_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct acpi_tad_rt rt;
char *str, *s;
int val, ret = -ENODATA;
str = kmemdup_nul(buf, count, GFP_KERNEL);
if (!str)
return -ENOMEM;
s = acpi_tad_rt_next_field(str, &val);
if (!s)
goto out_free;
rt.year = val;
s = acpi_tad_rt_next_field(s, &val);
if (!s)
goto out_free;
rt.month = val;
s = acpi_tad_rt_next_field(s, &val);
if (!s)
goto out_free;
rt.day = val;
s = acpi_tad_rt_next_field(s, &val);
if (!s)
goto out_free;
rt.hour = val;
s = acpi_tad_rt_next_field(s, &val);
if (!s)
goto out_free;
rt.minute = val;
s = acpi_tad_rt_next_field(s, &val);
if (!s)
goto out_free;
rt.second = val;
s = acpi_tad_rt_next_field(s, &val);
if (!s)
goto out_free;
rt.tz = val;
if (kstrtoint(s, 10, &val))
goto out_free;
rt.daylight = val;
rt.valid = 0;
rt.msec = 0;
memset(rt.padding, 0, 3);
ret = acpi_tad_set_real_time(dev, &rt);
out_free:
kfree(str);
return ret ? ret : count;
}
static ssize_t time_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct acpi_tad_rt rt;
int ret;
ret = acpi_tad_get_real_time(dev, &rt);
if (ret)
return ret;
return sprintf(buf, "%u:%u:%u:%u:%u:%u:%d:%u\n",
rt.year, rt.month, rt.day, rt.hour, rt.minute, rt.second,
rt.tz, rt.daylight);
}
static DEVICE_ATTR_RW(time);
static struct attribute *acpi_tad_time_attrs[] = {
&dev_attr_time.attr,
NULL,
};
static const struct attribute_group acpi_tad_time_attr_group = {
.attrs = acpi_tad_time_attrs,
};
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;
}
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);
}
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);
}
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);
}
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);
}
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);
}
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);
}
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;
}
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);
}
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);
}
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);
}
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;
}
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);
}
static DEVICE_ATTR_RW(ac_alarm);
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;
}
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);
}
static DEVICE_ATTR_RW(ac_policy);
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;
}
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);
}
static DEVICE_ATTR_RW(ac_status);
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;
}
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);
}
static DEVICE_ATTR_RW(dc_alarm);
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;
}
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);
}
static DEVICE_ATTR_RW(dc_policy);
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;
}
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);
}
static DEVICE_ATTR_RW(dc_status);
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);
}
static void acpi_tad_remove(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
acpi_handle handle = ACPI_HANDLE(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);
acpi_remove_cmos_rtc_space_handler(handle);
}
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;
ret = acpi_install_cmos_rtc_space_handler(handle);
if (ret < 0) {
dev_info(dev, "Unable to install space handler\n");
return -ENODEV;
}
/*
* 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");
ret = -ENODEV;
goto remove_handler;
}
if (!(caps & ACPI_TAD_AC_WAKE)) {
dev_info(dev, "Unsupported capabilities\n");
ret = -ENODEV;
goto remove_handler;
}
if (!acpi_has_method(handle, "_PRW")) {
dev_info(dev, "Missing _PRW\n");
ret = -ENODEV;
goto remove_handler;
}
dd = devm_kzalloc(dev, sizeof(*dd), GFP_KERNEL);
if (!dd) {
ret = -ENOMEM;
goto remove_handler;
}
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_MAY_SKIP_RESUME);
/*
* 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;
}
if (caps & ACPI_TAD_RT) {
ret = sysfs_create_group(&dev->kobj, &acpi_tad_time_attr_group);
if (ret)
goto fail;
}
return 0;
fail:
acpi_tad_remove(pdev);
/* Don't fallthrough because cmos rtc space handler is removed in acpi_tad_remove() */
return ret;
remove_handler:
acpi_remove_cmos_rtc_space_handler(handle);
return ret;
}
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_new = acpi_tad_remove,
};
MODULE_DEVICE_TABLE(acpi, acpi_tad_ids);
module_platform_driver(acpi_tad_driver);
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