power.c

Linux Kernel 2.6.9 for OMAP1710

	arg.integer.value = 0;	
	/* Execute PSW */
	status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL);
	if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluate _PSW\n"));
		dev->wakeup.flags.valid = 0;
		return -1;
	}

	/* Close power resource */
	for (i = 0; i < dev->wakeup.resources.count; i++) {
		ret = acpi_power_off_device(dev->wakeup.resources.handles[i]);
		if (ret) {
			ACPI_DEBUG_PRINT((ACPI_DB_ERROR, 
				"Error transition power state\n"));
			dev->wakeup.flags.valid = 0;
			return -1;
		}
	}

	return ret;
}

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

int
acpi_power_get_inferred_state (
	struct acpi_device	*device)
{
	int			result = 0;
	struct acpi_handle_list	*list = NULL;
	int			list_state = 0;
	int			i = 0;

	ACPI_FUNCTION_TRACE("acpi_power_get_inferred_state");

	if (!device)
		return_VALUE(-EINVAL);

	device->power.state = ACPI_STATE_UNKNOWN;

	/*
	 * We know a device's inferred power state when all the resources
	 * required for a given D-state are 'on'.
	 */
	for (i=ACPI_STATE_D0; i<ACPI_STATE_D3; i++) {
		list = &device->power.states[i].resources;
		if (list->count < 1)
			continue;

		result = acpi_power_get_list_state(list, &list_state);
		if (result)
			return_VALUE(result);

		if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
			device->power.state = i;
			return_VALUE(0);
		}
	}

	device->power.state = ACPI_STATE_D3;

	return_VALUE(0);
}


int
acpi_power_transition (
	struct acpi_device	*device,
	int			state)
{
	int			result = 0;
	struct acpi_handle_list	*cl = NULL;	/* Current Resources */
	struct acpi_handle_list	*tl = NULL;	/* Target Resources */
	int			i = 0;

	ACPI_FUNCTION_TRACE("acpi_power_transition");

	if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
		return_VALUE(-EINVAL);

	if ((device->power.state < ACPI_STATE_D0) || (device->power.state > ACPI_STATE_D3))
		return_VALUE(-ENODEV);

	cl = &device->power.states[device->power.state].resources;
	tl = &device->power.states[state].resources;

	device->power.state = ACPI_STATE_UNKNOWN;

	if (!cl->count && !tl->count) {
		result = -ENODEV;
		goto end;
	}

	/* TBD: Resources must be ordered. */

	/*
	 * First we reference all power resources required in the target list
	 * (e.g. so the device doesn't lose power while transitioning).
	 */
	for (i=0; i<tl->count; i++) {
		result = acpi_power_on(tl->handles[i]);
		if (result)
			goto end;
	}

	/*
	 * Then we dereference all power resources used in the current list.
	 */
	for (i=0; i<cl->count; i++) {
		result = acpi_power_off_device(cl->handles[i]);
		if (result)
			goto end;
	}

	/* We shouldn't change the state till all above operations succeed */
	device->power.state = state;
end:
	if (result)
		ACPI_DEBUG_PRINT((ACPI_DB_WARN, 
			"Error transitioning device [%s] to D%d\n",
			device->pnp.bus_id, state));

	return_VALUE(result);
}


/* --------------------------------------------------------------------------
                              FS Interface (/proc)
   -------------------------------------------------------------------------- */

struct proc_dir_entry		*acpi_power_dir;

static int acpi_power_seq_show(struct seq_file *seq, void *offset)
{
	struct acpi_power_resource *resource = NULL;

	ACPI_FUNCTION_TRACE("acpi_power_seq_show");

	resource = (struct acpi_power_resource *)seq->private;

	if (!resource)
		goto end;

	seq_puts(seq, "state:                   ");
	switch (resource->state) {
	case ACPI_POWER_RESOURCE_STATE_ON:
		seq_puts(seq, "on\n");
		break;
	case ACPI_POWER_RESOURCE_STATE_OFF:
		seq_puts(seq, "off\n");
		break;
	default:
		seq_puts(seq, "unknown\n");
		break;
	}

	seq_printf(seq, "system level:            S%d\n"
			"order:                   %d\n"
			"reference count:         %d\n",
			resource->system_level,
			resource->order,
			resource->references);

end:
	return 0;
}

static int acpi_power_open_fs(struct inode *inode, struct file *file)
{
	return single_open(file, acpi_power_seq_show, PDE(inode)->data);
}

static int
acpi_power_add_fs (
	struct acpi_device	*device)
{
	struct proc_dir_entry	*entry = NULL;

	ACPI_FUNCTION_TRACE("acpi_power_add_fs");

	if (!device)
		return_VALUE(-EINVAL);

	if (!acpi_device_dir(device)) {
		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
			acpi_power_dir);
		if (!acpi_device_dir(device))
			return_VALUE(-ENODEV);
	}

	/* 'status' [R] */
	entry = create_proc_entry(ACPI_POWER_FILE_STATUS,
		S_IRUGO, acpi_device_dir(device));
	if (!entry)
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
			"Unable to create '%s' fs entry\n",
			ACPI_POWER_FILE_STATUS));
	else {
		entry->proc_fops = &acpi_power_fops;
		entry->data = acpi_driver_data(device);
	}

	return_VALUE(0);
}


static int
acpi_power_remove_fs (
	struct acpi_device	*device)
{
	ACPI_FUNCTION_TRACE("acpi_power_remove_fs");

	if (acpi_device_dir(device)) {
		remove_proc_entry(ACPI_POWER_FILE_STATUS,
				  acpi_device_dir(device));
		remove_proc_entry(acpi_device_bid(device), acpi_power_dir);
		acpi_device_dir(device) = NULL;
	}

	return_VALUE(0);
}


/* --------------------------------------------------------------------------
                                Driver Interface
   -------------------------------------------------------------------------- */

int
acpi_power_add (
	struct acpi_device	*device)
{
	int			result = 0;
	acpi_status		status = AE_OK;
	struct acpi_power_resource *resource = NULL;
	union acpi_object	acpi_object;
	struct acpi_buffer	buffer = {sizeof(acpi_object), &acpi_object};

	ACPI_FUNCTION_TRACE("acpi_power_add");

	if (!device)
		return_VALUE(-EINVAL);

	resource = kmalloc(sizeof(struct acpi_power_resource), GFP_KERNEL);
	if (!resource)
		return_VALUE(-ENOMEM);
	memset(resource, 0, sizeof(struct acpi_power_resource));

	resource->handle = device->handle;
	strcpy(resource->name, device->pnp.bus_id);
	strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
	strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
	acpi_driver_data(device) = resource;

	/* Evalute the object to get the system level and resource order. */
	status = acpi_evaluate_object(resource->handle, NULL, NULL, &buffer);
	if (ACPI_FAILURE(status)) {
		result = -ENODEV;
		goto end;
	}
	resource->system_level = acpi_object.power_resource.system_level;
	resource->order = acpi_object.power_resource.resource_order;

	result = acpi_power_get_state(resource);
	if (result)
		goto end;

	switch (resource->state) {
	case ACPI_POWER_RESOURCE_STATE_ON:
		device->power.state = ACPI_STATE_D0;
		break;
	case ACPI_POWER_RESOURCE_STATE_OFF:
		device->power.state = ACPI_STATE_D3;
		break;
	default:
		device->power.state = ACPI_STATE_UNKNOWN;
		break;
	}

	result = acpi_power_add_fs(device);
	if (result)
		goto end;
	
	printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
		acpi_device_bid(device), resource->state?"on":"off");

end:
	if (result)
		kfree(resource);
	
	return_VALUE(result);
}


int
acpi_power_remove (
	struct acpi_device	*device,
	int			type)
{
	struct acpi_power_resource *resource = NULL;

	ACPI_FUNCTION_TRACE("acpi_power_remove");

	if (!device || !acpi_driver_data(device))
		return_VALUE(-EINVAL);

	resource = (struct acpi_power_resource *) acpi_driver_data(device);

	acpi_power_remove_fs(device);

	kfree(resource);

	return_VALUE(0);
}


static int __init acpi_power_init (void)
{
	int			result = 0;

	ACPI_FUNCTION_TRACE("acpi_power_init");

	if (acpi_disabled)
		return_VALUE(0);

	INIT_LIST_HEAD(&acpi_power_resource_list);

	acpi_power_dir = proc_mkdir(ACPI_POWER_CLASS, acpi_root_dir);
	if (!acpi_power_dir)
		return_VALUE(-ENODEV);

	result = acpi_bus_register_driver(&acpi_power_driver);
	if (result < 0) {
		remove_proc_entry(ACPI_POWER_CLASS, acpi_root_dir);
		return_VALUE(-ENODEV);
	}

	return_VALUE(0);
}

subsys_initcall(acpi_power_init);