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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2021-11-10 16:01:09 +0300
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2021-11-10 16:01:09 +0300
commit2c49dabad80d2177045554328da679f37b767ac9 (patch)
tree300e95bbb0cbefc524006dd287070b9d2f7b7137 /drivers/acpi
parent452a3e723f75880757acf87b053935c43aa89f89 (diff)
parentdff5acfd87e17ce8be3566b9948dc5ad558b0425 (diff)
downloadlinux-2c49dabad80d2177045554328da679f37b767ac9.tar.xz
Merge branch 'acpi-dsc'
Merge new ACPI device configuration object _DSC support for 5.16-rc1. * acpi-dsc: Documentation: ACPI: Fix non-D0 probe _DSC object example at24: Support probing while in non-zero ACPI D state media: i2c: imx319: Support device probe in non-zero ACPI D state ACPI: Add a convenience function to tell a device is in D0 state Documentation: ACPI: Document _DSC object usage for enum power state i2c: Allow an ACPI driver to manage the device's power state during probe ACPI: scan: Obtain device's desired enumeration power state
Diffstat (limited to 'drivers/acpi')
-rw-r--r--drivers/acpi/device_pm.c26
-rw-r--r--drivers/acpi/scan.c4
2 files changed, 30 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/drivers/acpi/scan.c b/drivers/acpi/scan.c
index dce2c291b982..a50f1967c73d 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1017,6 +1017,7 @@ static void acpi_bus_init_power_state(struct acpi_device *device, int state)
static void acpi_bus_get_power_flags(struct acpi_device *device)
{
+ unsigned long long dsc = ACPI_STATE_D0;
u32 i;
/* Presence of _PS0|_PR0 indicates 'power manageable' */
@@ -1038,6 +1039,9 @@ static void acpi_bus_get_power_flags(struct acpi_device *device)
if (acpi_has_method(device->handle, "_DSW"))
device->power.flags.dsw_present = 1;
+ acpi_evaluate_integer(device->handle, "_DSC", NULL, &dsc);
+ device->power.state_for_enumeration = dsc;
+
/*
* Enumerate supported power management states
*/