diff options
| -rw-r--r-- | drivers/acpi/x86/s2idle.c | 24 | ||||
| -rw-r--r-- | include/linux/acpi.h | 6 |
2 files changed, 30 insertions, 0 deletions
diff --git a/drivers/acpi/x86/s2idle.c b/drivers/acpi/x86/s2idle.c index 1aa3cd5677bd..08f7c6708206 100644 --- a/drivers/acpi/x86/s2idle.c +++ b/drivers/acpi/x86/s2idle.c @@ -299,6 +299,30 @@ free_acpi_buffer: ACPI_FREE(out_obj); } +/** + * acpi_get_lps0_constraint - Get the LPS0 constraint for a device. + * @adev: Device to get the constraint for. + * + * The LPS0 constraint is the shallowest (minimum) power state in which the + * device can be so as to allow the platform as a whole to achieve additional + * energy conservation by utilizing a system-wide low-power state. + * + * Returns: + * - ACPI power state value of the constraint for @adev on success. + * - Otherwise, ACPI_STATE_UNKNOWN. + */ +int acpi_get_lps0_constraint(struct acpi_device *adev) +{ + struct lpi_constraints *entry; + + for_each_lpi_constraint(entry) { + if (adev->handle == entry->handle) + return entry->min_dstate; + } + + return ACPI_STATE_UNKNOWN; +} + static void lpi_check_constraints(void) { struct lpi_constraints *entry; diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 6b4966e5d7b1..9e2a15dd33e4 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -1109,6 +1109,12 @@ struct acpi_s2idle_dev_ops { }; int acpi_register_lps0_dev(struct acpi_s2idle_dev_ops *arg); void acpi_unregister_lps0_dev(struct acpi_s2idle_dev_ops *arg); +int acpi_get_lps0_constraint(struct acpi_device *adev); +#else /* CONFIG_SUSPEND && CONFIG_X86 */ +static inline int acpi_get_lps0_constraint(struct device *dev) +{ + return ACPI_STATE_UNKNOWN; +} #endif /* CONFIG_SUSPEND && CONFIG_X86 */ #ifndef CONFIG_IA64 void arch_reserve_mem_area(acpi_physical_address addr, size_t size); |