int acpi_bus_init_power(struct acpi_device *device)
{
int state;
int result;
if (!device)
return -EINVAL;
device->power.state = ACPI_STATE_UNKNOWN;
result = acpi_device_get_power(device, &state);
if (result)
return result;
if (state < ACPI_STATE_D3_COLD && device->power.flags.power_resources) {
result = acpi_power_on_resources(device, state);
if (result)
return result;
result = acpi_dev_pm_explicit_set(device, state);
if (result)
return result;
} else if (state == ACPI_STATE_UNKNOWN) {
/* No power resources and missing _PSC? Try to force D0. */
state = ACPI_STATE_D0;
result = acpi_dev_pm_explicit_set(device, state);
if (result)
return result;
}
device->power.state = state;
return 0;
}
/**
* acpi_device_fix_up_power - Force device with missing _PSC into D0.
* @device: Device object whose power state is to be fixed up.
*
* Devices without power resources and _PSC, but having _PS0 and _PS3 defined,
* are assumed to be put into D0 by the BIOS. However, in some cases that may
* not be the case and this function should be used then.
*/
int acpi_device_fix_up_power(struct acpi_device *device)
{
int ret = 0;
if (!device->power.flags.power_resources
&& !device->power.flags.explicit_get
&& device->power.state == ACPI_STATE_D0)
ret = acpi_dev_pm_explicit_set(device, ACPI_STATE_D0);
return ret;
}
int acpi_bus_init_power(struct acpi_device *device)
{
int state;
int result;
if (!device)
return -EINVAL;
device->power.state = ACPI_STATE_UNKNOWN;
if (!acpi_device_is_present(device))
return -ENXIO;
result = acpi_device_get_power(device, &state);
if (result)
return result;
if (state < ACPI_STATE_D3_COLD && device->power.flags.power_resources) {
/* Reference count the power resources. */
result = acpi_power_on_resources(device, state);
if (result)
return result;
if (state == ACPI_STATE_D0) {
/*
* If _PSC is not present and the state inferred from
* power resources appears to be D0, it still may be
* necessary to execute _PS0 at this point, because
* another device using the same power resources may
* have been put into D0 previously and that's why we
* see D0 here.
*/
result = acpi_dev_pm_explicit_set(device, state);
if (result)
return result;
}
} else if (state == ACPI_STATE_UNKNOWN) {
/*
* No power resources and missing _PSC? Cross fingers and make
* it D0 in hope that this is what the BIOS put the device into.
* [We tried to force D0 here by executing _PS0, but that broke
* Toshiba P870-303 in a nasty way.]
*/
state = ACPI_STATE_D0;
}
device->power.state = state;
return 0;
}
int acpi_bus_init_power(struct acpi_device *device)
{
int state;
int result;
if (!device)
return -EINVAL;
device->power.state = ACPI_STATE_UNKNOWN;
if (!acpi_device_is_present(device))
return -ENXIO;
result = acpi_device_get_power(device, &state);
if (result)
return result;
if (state < ACPI_STATE_D3_COLD && device->power.flags.power_resources) {
result = acpi_power_on_resources(device, state);
if (result)
return result;
result = acpi_dev_pm_explicit_set(device, state);
if (result)
return result;
} else if (state == ACPI_STATE_UNKNOWN) {
/*
* No power resources and missing _PSC? Cross fingers and make
* it D0 in hope that this is what the BIOS put the device into.
* [We tried to force D0 here by executing _PS0, but that broke
* Toshiba P870-303 in a nasty way.]
*/
state = ACPI_STATE_D0;
}
device->power.state = state;
return 0;
}
/**
* acpi_device_set_power - Set power state of an ACPI device.
* @device: Device to set the power state of.
* @state: New power state to set.
*
* Callers must ensure that the device is power manageable before using this
* function.
*/
int acpi_device_set_power(struct acpi_device *device, int state)
{
int result = 0;
bool cut_power = false;
if (!device || !device->flags.power_manageable
|| (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD))
return -EINVAL;
/* Make sure this is a valid target state */
if (state == device->power.state) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] already in %s\n",
device->pnp.bus_id,
acpi_power_state_string(state)));
return 0;
}
if (!device->power.states[state].flags.valid) {
dev_warn(&device->dev, "Power state %s not supported\n",
acpi_power_state_string(state));
return -ENODEV;
}
if (!device->power.flags.ignore_parent &&
device->parent && (state < device->parent->power.state)) {
dev_warn(&device->dev,
"Cannot transition to power state %s for parent in %s\n",
acpi_power_state_string(state),
acpi_power_state_string(device->parent->power.state));
return -ENODEV;
}
/* For D3cold we should first transition into D3hot. */
if (state == ACPI_STATE_D3_COLD
&& device->power.states[ACPI_STATE_D3_COLD].flags.os_accessible) {
state = ACPI_STATE_D3_HOT;
cut_power = true;
}
if (state < device->power.state && state != ACPI_STATE_D0
&& device->power.state >= ACPI_STATE_D3_HOT) {
dev_warn(&device->dev,
"Cannot transition to non-D0 state from D3\n");
return -ENODEV;
}
/*
* Transition Power
* ----------------
* In accordance with the ACPI specification first apply power (via
* power resources) and then evaluate _PSx.
*/
if (device->power.flags.power_resources) {
result = acpi_power_transition(device, state);
if (result)
goto end;
}
result = acpi_dev_pm_explicit_set(device, state);
if (result)
goto end;
if (cut_power) {
device->power.state = state;
state = ACPI_STATE_D3_COLD;
result = acpi_power_transition(device, state);
}
end:
if (result) {
dev_warn(&device->dev, "Failed to change power state to %s\n",
acpi_power_state_string(state));
} else {
device->power.state = state;
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Device [%s] transitioned to %s\n",
device->pnp.bus_id,
acpi_power_state_string(state)));
}
return result;
}
/**
* acpi_device_set_power - Set power state of an ACPI device.
* @device: Device to set the power state of.
* @state: New power state to set.
*
* Callers must ensure that the device is power manageable before using this
* function.
*/
int acpi_device_set_power(struct acpi_device *device, int state)
{
int target_state = state;
int result = 0;
if (!device || !device->flags.power_manageable
|| (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD))
return -EINVAL;
/* Make sure this is a valid target state */
if (state == device->power.state) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] already in %s\n",
device->pnp.bus_id,
acpi_power_state_string(state)));
return 0;
}
if (state == ACPI_STATE_D3_COLD) {
/*
* For transitions to D3cold we need to execute _PS3 and then
* possibly drop references to the power resources in use.
*/
state = ACPI_STATE_D3_HOT;
/* If _PR3 is not available, use D3hot as the target state. */
if (!device->power.states[ACPI_STATE_D3_COLD].flags.valid)
target_state = state;
} else if (!device->power.states[state].flags.valid) {
dev_warn(&device->dev, "Power state %s not supported\n",
acpi_power_state_string(state));
return -ENODEV;
}
if (!device->power.flags.ignore_parent &&
device->parent && (state < device->parent->power.state)) {
dev_warn(&device->dev,
"Cannot transition to power state %s for parent in %s\n",
acpi_power_state_string(state),
acpi_power_state_string(device->parent->power.state));
return -ENODEV;
}
/*
* Transition Power
* ----------------
* In accordance with ACPI 6, _PSx is executed before manipulating power
* resources, unless the target state is D0, in which case _PS0 is
* supposed to be executed after turning the power resources on.
*/
if (state > ACPI_STATE_D0) {
/*
* According to ACPI 6, devices cannot go from lower-power
* (deeper) states to higher-power (shallower) states.
*/
if (state < device->power.state) {
dev_warn(&device->dev, "Cannot transition from %s to %s\n",
acpi_power_state_string(device->power.state),
acpi_power_state_string(state));
return -ENODEV;
}
result = acpi_dev_pm_explicit_set(device, state);
if (result)
goto end;
if (device->power.flags.power_resources)
result = acpi_power_transition(device, target_state);
} else {
if (device->power.flags.power_resources) {
result = acpi_power_transition(device, ACPI_STATE_D0);
if (result)
goto end;
}
result = acpi_dev_pm_explicit_set(device, ACPI_STATE_D0);
}
end:
if (result) {
dev_warn(&device->dev, "Failed to change power state to %s\n",
acpi_power_state_string(state));
} else {
device->power.state = target_state;
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Device [%s] transitioned to %s\n",
device->pnp.bus_id,
acpi_power_state_string(state)));
}
return result;
}
/**
* acpi_device_set_power - Set power state of an ACPI device.
* @device: Device to set the power state of.
* @state: New power state to set.
*
* Callers must ensure that the device is power manageable before using this
* function.
*/
int acpi_device_set_power(struct acpi_device *device, int state)
{
int result = 0;
bool cut_power = false;
if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD))
return -EINVAL;
/* Make sure this is a valid target state */
if (state == device->power.state) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device is already at %s\n",
acpi_power_state_string(state)));
return 0;
}
if (!device->power.states[state].flags.valid) {
printk(KERN_WARNING PREFIX "Device does not support %s\n",
acpi_power_state_string(state));
return -ENODEV;
}
if (device->parent && (state < device->parent->power.state)) {
printk(KERN_WARNING PREFIX
"Cannot set device to a higher-powered"
" state than parent\n");
return -ENODEV;
}
/* For D3cold we should first transition into D3hot. */
if (state == ACPI_STATE_D3_COLD
&& device->power.states[ACPI_STATE_D3_COLD].flags.os_accessible) {
state = ACPI_STATE_D3_HOT;
cut_power = true;
}
if (state < device->power.state && state != ACPI_STATE_D0
&& device->power.state >= ACPI_STATE_D3_HOT) {
printk(KERN_WARNING PREFIX
"Cannot transition to non-D0 state from D3\n");
return -ENODEV;
}
/*
* Transition Power
* ----------------
* In accordance with the ACPI specification first apply power (via
* power resources) and then evalute _PSx.
*/
if (device->power.flags.power_resources) {
result = acpi_power_transition(device, state);
if (result)
goto end;
}
result = acpi_dev_pm_explicit_set(device, state);
if (result)
goto end;
if (cut_power) {
device->power.state = state;
state = ACPI_STATE_D3_COLD;
result = acpi_power_transition(device, state);
}
end:
if (result) {
printk(KERN_WARNING PREFIX
"Device [%s] failed to transition to %s\n",
device->pnp.bus_id,
acpi_power_state_string(state));
} else {
device->power.state = state;
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Device [%s] transitioned to %s\n",
device->pnp.bus_id,
acpi_power_state_string(state)));
}
return result;
}
