diff options
Diffstat (limited to 'drivers/acpi/device_pm.c')
| -rw-r--r-- | drivers/acpi/device_pm.c | 362 |
1 files changed, 355 insertions, 7 deletions
diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c index f09dc987cf17..dd314ef9bff1 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 +100,293 @@ acpi_status acpi_remove_pm_notifier(struct acpi_device *adev, } /** + * 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 "D3cold"; + 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; +} + +static int acpi_dev_pm_explicit_set(struct acpi_device *adev, int state) +{ + if (adev->power.states[state].flags.explicit_set) { + char method[5] = { '_', 'P', 'S', '0' + state, '\0' }; + acpi_status status; + + status = acpi_evaluate_object(adev->handle, method, NULL, NULL); + if (ACPI_FAILURE(status)) + return -ENODEV; + } + 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 || (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; +} +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 (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; +} + +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; + + if (state == ACPI_STATE_UNKNOWN) + state = ACPI_STATE_D0; + + 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. @@ -213,7 +506,7 @@ int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p, int d_max_in) acpi_handle handle = DEVICE_ACPI_HANDLE(dev); struct acpi_device *adev; - if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) { + if (!handle || acpi_bus_get_device(handle, &adev)) { dev_dbg(dev, "ACPI handle without context in %s!\n", __func__); return -ENODEV; } @@ -290,7 +583,7 @@ int acpi_pm_device_run_wake(struct device *phys_dev, bool enable) return -EINVAL; handle = DEVICE_ACPI_HANDLE(phys_dev); - if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) { + if (!handle || acpi_bus_get_device(handle, &adev)) { dev_dbg(phys_dev, "ACPI handle without context in %s!\n", __func__); return -ENODEV; @@ -304,7 +597,7 @@ static inline void acpi_wakeup_device(acpi_handle handle, u32 event, void *context) {} #endif /* CONFIG_PM_RUNTIME */ - #ifdef CONFIG_PM_SLEEP +#ifdef CONFIG_PM_SLEEP /** * __acpi_device_sleep_wake - Enable or disable device to wake up the system. * @dev: Device to enable/desible to wake up the system. @@ -334,7 +627,7 @@ int acpi_pm_device_sleep_wake(struct device *dev, bool enable) return -EINVAL; handle = DEVICE_ACPI_HANDLE(dev); - if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) { + if (!handle || acpi_bus_get_device(handle, &adev)) { dev_dbg(dev, "ACPI handle without context in %s!\n", __func__); return -ENODEV; } @@ -353,13 +646,12 @@ int acpi_pm_device_sleep_wake(struct device *dev, bool enable) * acpi_dev_pm_get_node - Get ACPI device node for the given physical device. * @dev: Device to get the ACPI node for. */ -static struct acpi_device *acpi_dev_pm_get_node(struct device *dev) +struct acpi_device *acpi_dev_pm_get_node(struct device *dev) { acpi_handle handle = DEVICE_ACPI_HANDLE(dev); struct acpi_device *adev; - return handle && ACPI_SUCCESS(acpi_bus_get_device(handle, &adev)) ? - adev : NULL; + return handle && !acpi_bus_get_device(handle, &adev) ? adev : NULL; } /** @@ -666,3 +958,59 @@ void acpi_dev_pm_detach(struct device *dev, bool power_off) } } EXPORT_SYMBOL_GPL(acpi_dev_pm_detach); + +/** + * acpi_dev_pm_add_dependent - Add physical device depending for PM. + * @handle: Handle of ACPI device node. + * @depdev: Device depending on that node for PM. + */ +void acpi_dev_pm_add_dependent(acpi_handle handle, struct device *depdev) +{ + struct acpi_device_physical_node *dep; + struct acpi_device *adev; + + if (!depdev || acpi_bus_get_device(handle, &adev)) + return; + + mutex_lock(&adev->physical_node_lock); + + list_for_each_entry(dep, &adev->power_dependent, node) + if (dep->dev == depdev) + goto out; + + dep = kzalloc(sizeof(*dep), GFP_KERNEL); + if (dep) { + dep->dev = depdev; + list_add_tail(&dep->node, &adev->power_dependent); + } + + out: + mutex_unlock(&adev->physical_node_lock); +} +EXPORT_SYMBOL_GPL(acpi_dev_pm_add_dependent); + +/** + * acpi_dev_pm_remove_dependent - Remove physical device depending for PM. + * @handle: Handle of ACPI device node. + * @depdev: Device depending on that node for PM. + */ +void acpi_dev_pm_remove_dependent(acpi_handle handle, struct device *depdev) +{ + struct acpi_device_physical_node *dep; + struct acpi_device *adev; + + if (!depdev || acpi_bus_get_device(handle, &adev)) + return; + + mutex_lock(&adev->physical_node_lock); + + list_for_each_entry(dep, &adev->power_dependent, node) + if (dep->dev == depdev) { + list_del(&dep->node); + kfree(dep); + break; + } + + mutex_unlock(&adev->physical_node_lock); +} +EXPORT_SYMBOL_GPL(acpi_dev_pm_remove_dependent); |