diff options
| -rw-r--r-- | drivers/acpi/device_pm.c | 26 | ||||
| -rw-r--r-- | include/linux/acpi.h | 5 |
2 files changed, 31 insertions, 0 deletions
diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c index 0028b6b51c87..19b33c028f35 100644 --- a/drivers/acpi/device_pm.c +++ b/drivers/acpi/device_pm.c @@ -1400,4 +1400,30 @@ bool acpi_storage_d3(struct device *dev) } EXPORT_SYMBOL_GPL(acpi_storage_d3); +/** + * acpi_dev_state_d0 - Tell if the device is in D0 power state + * @dev: Physical device the ACPI power state of which to check + * + * On a system without ACPI, return true. On a system with ACPI, return true if + * the current ACPI power state of the device is D0, or false otherwise. + * + * Note that the power state of a device is not well-defined after it has been + * passed to acpi_device_set_power() and before that function returns, so it is + * not valid to ask for the ACPI power state of the device in that time frame. + * + * This function is intended to be used in a driver's probe or remove + * function. See Documentation/firmware-guide/acpi/low-power-probe.rst for + * more information. + */ +bool acpi_dev_state_d0(struct device *dev) +{ + struct acpi_device *adev = ACPI_COMPANION(dev); + + if (!adev) + return true; + + return adev->power.state == ACPI_STATE_D0; +} +EXPORT_SYMBOL_GPL(acpi_dev_state_d0); + #endif /* CONFIG_PM */ diff --git a/include/linux/acpi.h b/include/linux/acpi.h index fbc2146050a4..df70fc27afd7 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -1016,6 +1016,7 @@ int acpi_subsys_runtime_suspend(struct device *dev); int acpi_subsys_runtime_resume(struct device *dev); int acpi_dev_pm_attach(struct device *dev, bool power_on); bool acpi_storage_d3(struct device *dev); +bool acpi_dev_state_d0(struct device *dev); #else static inline int acpi_subsys_runtime_suspend(struct device *dev) { return 0; } static inline int acpi_subsys_runtime_resume(struct device *dev) { return 0; } @@ -1027,6 +1028,10 @@ static inline bool acpi_storage_d3(struct device *dev) { return false; } +static inline bool acpi_dev_state_d0(struct device *dev) +{ + return true; +} #endif #if defined(CONFIG_ACPI) && defined(CONFIG_PM_SLEEP) |