예제 #1
0
파일: device_pm.c 프로젝트: AiWinters/linux
/**
 * 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;
}
예제 #2
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;
}
예제 #3
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;
}
예제 #4
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 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;
}
예제 #5
0
파일: device_pm.c 프로젝트: AiWinters/linux
/**
 * 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;
}