ACPI / PM: Move device power management functions to device_pm.c
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>
diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c
index 8be4b29..8bca746 100644
--- a/drivers/acpi/device_pm.c
+++ b/drivers/acpi/device_pm.c
@@ -30,6 +30,12 @@
#include <acpi/acpi.h>
#include <acpi/acpi_bus.h>
+#include <acpi/acpi_drivers.h>
+
+#include "internal.h"
+
+#define _COMPONENT ACPI_POWER_COMPONENT
+ACPI_MODULE_NAME("device_pm");
static DEFINE_MUTEX(acpi_pm_notifier_lock);
@@ -94,6 +100,288 @@
}
/**
+ * 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);
+
+/**
* acpi_device_power_state - Get preferred power state of ACPI device.
* @dev: Device whose preferred target power state to return.
* @adev: ACPI device node corresponding to @dev.