static int __acpi_bus_get_power(struct acpi_device *device, int *state)
{
int result = ACPI_STATE_UNKNOWN;
if (!device || !state)
return -EINVAL;
if (!device->flags.power_manageable) {
/* TBD: Non-recursive algorithm for walking up hierarchy. */
*state = device->parent ?
device->parent->power.state : ACPI_STATE_D0;
goto out;
}
/*
* Get the device's power state either directly (via _PSC) or
* indirectly (via power resources).
*/
if (device->power.flags.explicit_get) {
unsigned long long psc;
acpi_status status = acpi_evaluate_integer(device->handle,
"_PSC", NULL, &psc);
if (ACPI_FAILURE(status))
return -ENODEV;
result = psc;
}
/* The test below covers ACPI_STATE_UNKNOWN too. */
if (result <= ACPI_STATE_D2) {
; /* Do nothing. */
} else if (device->power.flags.power_resources) {
int error = acpi_power_get_inferred_state(device, &result);
if (error)
return error;
} else if (result == ACPI_STATE_D3_HOT) {
result = ACPI_STATE_D3;
}
/*
* If we were unsure about the device parent's power state up to this
* point, the fact that the device is in D0 implies that the parent has
* to be in D0 too.
*/
if (device->parent && device->parent->power.state == ACPI_STATE_UNKNOWN
&& result == ACPI_STATE_D0)
device->parent->power.state = ACPI_STATE_D0;
*state = result;
out:
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is %s\n",
device->pnp.bus_id, state_string(*state)));
return 0;
}
int
acpi_bus_get_power (
acpi_handle handle,
int *state)
{
int result = 0;
acpi_status status = 0;
struct acpi_device *device = NULL;
unsigned long psc = 0;
ACPI_FUNCTION_TRACE("acpi_bus_get_power");
result = acpi_bus_get_device(handle, &device);
if (result)
return_VALUE(result);
*state = ACPI_STATE_UNKNOWN;
if (!device->flags.power_manageable) {
/* TBD: Non-recursive algorithm for walking up hierarchy */
if (device->parent)
*state = device->parent->power.state;
else
*state = ACPI_STATE_D0;
}
else {
/*
* Get the device's power state either directly (via _PSC) or
* indirectly (via power resources).
*/
if (device->power.flags.explicit_get) {
status = acpi_evaluate_integer(device->handle, "_PSC",
NULL, &psc);
if (ACPI_FAILURE(status))
return_VALUE(-ENODEV);
device->power.state = (int) psc;
}
else if (device->power.flags.power_resources) {
result = acpi_power_get_inferred_state(device);
if (result)
return_VALUE(result);
}
*state = device->power.state;
}
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is D%d\n",
device->pnp.bus_id, device->power.state));
return_VALUE(0);
}
/* Resume the device when all power resources in _PR0 are on */
static void acpi_power_on_device(struct acpi_power_managed_device *device)
{
struct acpi_device *acpi_dev;
acpi_handle handle = device->handle;
int state;
if (acpi_bus_get_device(handle, &acpi_dev))
return;
if(acpi_power_get_inferred_state(acpi_dev, &state))
return;
if (state == ACPI_STATE_D0 && pm_runtime_suspended(device->dev))
pm_request_resume(device->dev);
}
static int __acpi_bus_get_power(struct acpi_device *device, int *state)
{
int result = 0;
acpi_status status = 0;
unsigned long long psc = 0;
if (!device || !state)
return -EINVAL;
*state = ACPI_STATE_UNKNOWN;
if (device->flags.power_manageable) {
/*
* Get the device's power state either directly (via _PSC) or
* indirectly (via power resources).
*/
if (device->power.flags.power_resources) {
result = acpi_power_get_inferred_state(device, state);
if (result)
return result;
} else if (device->power.flags.explicit_get) {
status = acpi_evaluate_integer(device->handle, "_PSC",
NULL, &psc);
if (ACPI_FAILURE(status))
return -ENODEV;
*state = (int)psc;
}
} else {
/* TBD: Non-recursive algorithm for walking up hierarchy. */
*state = device->parent ?
device->parent->power.state : ACPI_STATE_D0;
}
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is D%d\n",
device->pnp.bus_id, *state));
return 0;
}
/**
* acpi_device_get_power - Get power state of an ACPI device.
* @device: Device to get the power state of.
* @state: Place to store the power state of the device.
*
* This function does not update the device's power.state field, but it may
* update its parent's power.state field (when the parent's power state is
* unknown and the device's power state turns out to be D0).
*/
int acpi_device_get_power(struct acpi_device *device, int *state)
{
int result = ACPI_STATE_UNKNOWN;
if (!device || !state)
return -EINVAL;
if (!device->flags.power_manageable) {
/* TBD: Non-recursive algorithm for walking up hierarchy. */
*state = device->parent ?
device->parent->power.state : ACPI_STATE_D0;
goto out;
}
/*
* Get the device's power state from power resources settings and _PSC,
* if available.
*/
if (device->power.flags.power_resources) {
int error = acpi_power_get_inferred_state(device, &result);
if (error)
return error;
}
if (device->power.flags.explicit_get) {
acpi_handle handle = device->handle;
unsigned long long psc;
acpi_status status;
status = acpi_evaluate_integer(handle, "_PSC", NULL, &psc);
if (ACPI_FAILURE(status))
return -ENODEV;
/*
* The power resources settings may indicate a power state
* shallower than the actual power state of the device.
*
* Moreover, on systems predating ACPI 4.0, if the device
* doesn't depend on any power resources and _PSC returns 3,
* that means "power off". We need to maintain compatibility
* with those systems.
*/
if (psc > result && psc < ACPI_STATE_D3_COLD)
result = psc;
else if (result == ACPI_STATE_UNKNOWN)
result = psc > ACPI_STATE_D2 ? ACPI_STATE_D3_COLD : psc;
}
/*
* If we were unsure about the device parent's power state up to this
* point, the fact that the device is in D0 implies that the parent has
* to be in D0 too, except if ignore_parent is set.
*/
if (!device->power.flags.ignore_parent && device->parent
&& device->parent->power.state == ACPI_STATE_UNKNOWN
&& result == ACPI_STATE_D0)
device->parent->power.state = ACPI_STATE_D0;
*state = result;
out:
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is %s\n",
device->pnp.bus_id, acpi_power_state_string(*state)));
return 0;
}
