diff options
| -rw-r--r-- | Documentation/ABI/testing/sysfs-devices-platform-ACPI-TAD | 113 | ||||
| -rw-r--r-- | drivers/acpi/Kconfig | 13 | ||||
| -rw-r--r-- | drivers/acpi/Makefile | 1 | ||||
| -rw-r--r-- | drivers/acpi/acpi_tad.c | 473 |
4 files changed, 600 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-devices-platform-ACPI-TAD b/Documentation/ABI/testing/sysfs-devices-platform-ACPI-TAD new file mode 100644 index 000000000000..7e43cdce9a52 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-devices-platform-ACPI-TAD @@ -0,0 +1,113 @@ + ACPI Time and Alarm (TAD) device attributes. + +What: /sys/bus/platform/devices/ACPI000E:00/caps +Date: March 2018 +Contact: Rafael J. Wysocki <rafael.j.wysocki@intel.com> +Description: + (RO) Hexadecimal bitmask of the TAD attributes are reported by + the platform firmware (see ACPI 6.2, section 9.18.2): + + BIT(0): AC wakeup implemented if set + BIT(1): DC wakeup implemented if set + BIT(2): Get/set real time features implemented if set + BIT(3): Real time accuracy in milliseconds if set + BIT(4): Correct status reported for wakeups from S4/S5 if set + BIT(5): The AC timer wakes up from S4 if set + BIT(6): The AC timer wakes up from S5 if set + BIT(7): The DC timer wakes up from S4 if set + BIT(8): The DC timer wakes up from S5 if set + + The other bits are reserved. + +What: /sys/bus/platform/devices/ACPI000E:00/ac_alarm +Date: March 2018 +Contact: Rafael J. Wysocki <rafael.j.wysocki@intel.com> +Description: + (RW) The AC alarm timer value. + + Reads return the current AC alarm timer value in seconds or + "disabled", if the AC alarm is not set to wake up the system. + + Write a new AC alarm timer value in seconds or "disabled" to it + to set the AC alarm timer or to disable it, respectively. + + If the AC alarm timer is set through this attribute and it + expires, it will immediately wake up the system from the S3 + sleep state (and from S4/S5 too if supported) until its status + is explicitly cleared via the ac_status attribute. + +What: /sys/bus/platform/devices/ACPI000E:00/ac_policy +Date: March 2018 +Contact: Rafael J. Wysocki <rafael.j.wysocki@intel.com> +Description: + (RW) The AC alarm expired timer wake policy (see ACPI 6.2, + Section 9.18 for details). + + Reads return the current expired timer wake delay for the AC + alarm timer or "never", if the policy is to discard AC timer + wakeups if the system is on DC power. + + Write a new expired timer wake delay for the AC alarm timer in + seconds or "never" to it to set the expired timer wake delay for + the AC alarm timer or to set its expired wake policy to discard + wakeups if the system is on DC power, respectively. + +What: /sys/bus/platform/devices/ACPI000E:00/ac_status +Date: March 2018 +Contact: Rafael J. Wysocki <rafael.j.wysocki@intel.com> +Description: + (RW) The AC alarm status. + + Reads return a hexadecimal bitmask representing the AC alarm + timer status with the following meaning of bits (see ACPI 6.2, + Section 9.18.5): + + Bit(0): The timer has expired if set. + Bit(1): The timer has woken up the system from a sleep state + (S3 or S4/S5 if supported) if set. + + The other bits are reserved. + + Reads also cause the AC alarm timer status to be reset. + + Another way to reset the the status of the AC alarm timer is to + write (the number) 0 to this file. + + If the status return value indicates that the timer has expired, + it will immediately wake up the system from the S3 sleep state + (and from S4/S5 too if supported) until its status is explicitly + cleared through this attribute. + +What: /sys/bus/platform/devices/ACPI000E:00/dc_alarm +Date: March 2018 +Contact: Rafael J. Wysocki <rafael.j.wysocki@intel.com> +Description: + (RW,optional) The DC alarm timer value. + + This attribute is only present if the TAD supports a separate + DC timer. + + It is analogous to the ac_alarm attribute. + +What: /sys/bus/platform/devices/ACPI000E:00/dc_policy +Date: March 2018 +Contact: Rafael J. Wysocki <rafael.j.wysocki@intel.com> +Description: + (RW,optional) The DC alarm expired timer wake policy. + + This attribute is only present if the TAD supports a separate + DC timer. + + It is analogous to the ac_policy attribute. + +What: /sys/bus/platform/devices/ACPI000E:00/dc_status +Date: March 2018 +Contact: Rafael J. Wysocki <rafael.j.wysocki@intel.com> + +Description: + (RW,optional) The DC alarm status. + + This attribute is only present if the TAD supports a separate + DC timer. + + It is analogous to the ac_status attribute. diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig index f505e9a01b2d..7cea52ab4418 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -217,6 +217,19 @@ config ACPI_FAN To compile this driver as a module, choose M here: the module will be called fan. +config ACPI_TAD + tristate "ACPI Time and Alarm (TAD) Device Support" + depends on SYSFS && PM_SLEEP + help + The ACPI Time and Alarm (TAD) device is an alternative to the Real + Time Clock (RTC). Its wake timers allow the system to transition from + the S3 (or optionally S4/S5) state to S0 state after a time period + elapses. In comparison with the RTC Alarm, the TAD provides a larger + scale of flexibility in the wake timers. The time capabilities of the + TAD maintain the time of day information across platform power + transitions, and keep track of time even when the platform is turned + off. + config ACPI_DOCK bool "Dock" help diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile index 41954a601989..48e202752754 100644 --- a/drivers/acpi/Makefile +++ b/drivers/acpi/Makefile @@ -70,6 +70,7 @@ obj-$(CONFIG_ACPI_AC) += ac.o obj-$(CONFIG_ACPI_BUTTON) += button.o obj-$(CONFIG_ACPI_FAN) += fan.o obj-$(CONFIG_ACPI_VIDEO) += video.o +obj-$(CONFIG_ACPI_TAD) += acpi_tad.o obj-$(CONFIG_ACPI_PCI_SLOT) += pci_slot.o obj-$(CONFIG_ACPI_PROCESSOR) += processor.o obj-$(CONFIG_ACPI) += container.o diff --git a/drivers/acpi/acpi_tad.c b/drivers/acpi/acpi_tad.c new file mode 100644 index 000000000000..e99c4ed7e677 --- /dev/null +++ b/drivers/acpi/acpi_tad.c @@ -0,0 +1,473 @@ +// 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; +} + +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(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; +} + +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(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; +} + +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(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; +} + +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(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; +} + +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(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; +} + +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(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); +} + +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_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; +} + +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); |