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ACPI / PM: Move device power management functions to device_pm.c
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Move ACPI device power management functions from drivers/acpi/bus.c
to drivers/acpi/device_pm.c.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Rafael J. Wysocki committed Jan 19, 2013
1 parent 96bfd3c commit 9ce4e60
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Showing 4 changed files with 326 additions and 294 deletions.
293 changes: 0 additions & 293 deletions drivers/acpi/bus.c
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Original file line number Diff line number Diff line change
Expand Up @@ -178,299 +178,6 @@ int acpi_bus_get_private_data(acpi_handle handle, void **data)
}
EXPORT_SYMBOL(acpi_bus_get_private_data);

/* --------------------------------------------------------------------------
Power Management
-------------------------------------------------------------------------- */

/**
* acpi_power_state_string - String representation of ACPI device power state.
* @state: ACPI device power state to return the string representation of.
*/
const char *acpi_power_state_string(int state)
{
switch (state) {
case ACPI_STATE_D0:
return "D0";
case ACPI_STATE_D1:
return "D1";
case ACPI_STATE_D2:
return "D2";
case ACPI_STATE_D3_HOT:
return "D3hot";
case ACPI_STATE_D3_COLD:
return "D3";
default:
return "(unknown)";
}
}

/**
* 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 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, acpi_power_state_string(*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;
acpi_status status = AE_OK;
char object_name[5] = { '_', 'P', 'S', '0' + state, '\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;
object_name[3] = '3';
cut_power = true;
}

/*
* Transition Power
* ----------------
* On transitions to a high-powered state we first apply power (via
* power resources) then evalute _PSx. Conversly for transitions to
* a lower-powered state.
*/
if (state < device->power.state) {
if (device->power.state >= ACPI_STATE_D3_HOT &&
state != ACPI_STATE_D0) {
printk(KERN_WARNING PREFIX
"Cannot transition to non-D0 state from D3\n");
return -ENODEV;
}
if (device->power.flags.power_resources) {
result = acpi_power_transition(device, state);
if (result)
goto end;
}
if (device->power.states[state].flags.explicit_set) {
status = acpi_evaluate_object(device->handle,
object_name, NULL, NULL);
if (ACPI_FAILURE(status)) {
result = -ENODEV;
goto end;
}
}
} else {
if (device->power.states[state].flags.explicit_set) {
status = acpi_evaluate_object(device->handle,
object_name, NULL, NULL);
if (ACPI_FAILURE(status)) {
result = -ENODEV;
goto end;
}
}
if (device->power.flags.power_resources) {
result = acpi_power_transition(device, state);
if (result)
goto end;
}
}

if (cut_power)
result = acpi_power_transition(device, ACPI_STATE_D3_COLD);

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;
}
EXPORT_SYMBOL(acpi_device_set_power);


int acpi_bus_set_power(acpi_handle handle, int state)
{
struct acpi_device *device;
int result;

result = acpi_bus_get_device(handle, &device);
if (result)
return result;

if (!device->flags.power_manageable) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Device [%s] is not power manageable\n",
dev_name(&device->dev)));
return -ENODEV;
}

return acpi_device_set_power(device, state);
}
EXPORT_SYMBOL(acpi_bus_set_power);


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 (device->power.flags.power_resources)
result = acpi_power_on_resources(device, state);

if (!result)
device->power.state = state;

return result;
}


int acpi_bus_update_power(acpi_handle handle, int *state_p)
{
struct acpi_device *device;
int state;
int result;

result = acpi_bus_get_device(handle, &device);
if (result)
return result;

result = acpi_device_get_power(device, &state);
if (result)
return result;

result = acpi_device_set_power(device, state);
if (!result && state_p)
*state_p = state;

return result;
}
EXPORT_SYMBOL_GPL(acpi_bus_update_power);


bool acpi_bus_power_manageable(acpi_handle handle)
{
struct acpi_device *device;
int result;

result = acpi_bus_get_device(handle, &device);
return result ? false : device->flags.power_manageable;
}

EXPORT_SYMBOL(acpi_bus_power_manageable);

bool acpi_bus_can_wakeup(acpi_handle handle)
{
struct acpi_device *device;
int result;

result = acpi_bus_get_device(handle, &device);
return result ? false : device->wakeup.flags.valid;
}

EXPORT_SYMBOL(acpi_bus_can_wakeup);

static void acpi_print_osc_error(acpi_handle handle,
struct acpi_osc_context *context, char *error)
{
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