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- // 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_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 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;
- }
- 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_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);
- 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 = acpi_tad_remove,
- };
- MODULE_DEVICE_TABLE(acpi, acpi_tad_ids);
- module_platform_driver(acpi_tad_driver);
|