scan.c

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/*
 * scan.c - support for transforming the ACPI namespace into individual objects
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/acpi.h>

#include <acpi/acpi_drivers.h>
#include <acpi/acinterp.h>	/* for acpi_ex_eisa_id_to_string() */

#define _COMPONENT		ACPI_BUS_COMPONENT
ACPI_MODULE_NAME("scan");
#define STRUCT_TO_INT(s)	(*((int*)&s))
extern struct acpi_device *acpi_root;

#define ACPI_BUS_CLASS			"system_bus"
#define ACPI_BUS_HID			"LNXSYBUS"
#define ACPI_BUS_DEVICE_NAME		"System Bus"

static LIST_HEAD(acpi_device_list);
static LIST_HEAD(acpi_bus_id_list);
DEFINE_SPINLOCK(acpi_device_lock);
LIST_HEAD(acpi_wakeup_device_list);

struct acpi_device_bus_id{
	char bus_id[15];
	unsigned int instance_no;
	struct list_head node;
};

/*
 * Creates hid/cid(s) string needed for modalias and uevent
 * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
 * char *modalias: "acpi:IBM0001:ACPI0001"
*/
static int create_modalias(struct acpi_device *acpi_dev, char *modalias,
			   int size)
{
	int len;

	if (!acpi_dev->flags.hardware_id)
		return -ENODEV;

	len = snprintf(modalias, size, "acpi:%s:",
		       acpi_dev->pnp.hardware_id);
	if (len < 0 || len >= size)
		return -EINVAL;
	size -= len;

	if (acpi_dev->flags.compatible_ids) {
		struct acpi_compatible_id_list *cid_list;
		int i;
		int count;

		cid_list = acpi_dev->pnp.cid_list;
		for (i = 0; i < cid_list->count; i++) {
			count = snprintf(&modalias[len], size, "%s:",
					 cid_list->id[i].value);
			if (count < 0 || count >= size) {
				printk(KERN_ERR "acpi: %s cid[%i] exceeds event buffer size",
				       acpi_dev->pnp.device_name, i);
				break;
			}
			len += count;
			size -= count;
		}
	}

	modalias[len] = '\0';
	return len;
}

static ssize_t
acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, char *buf) {
	struct acpi_device *acpi_dev = to_acpi_device(dev);
	int len;

	/* Device has no HID and no CID or string is >1024 */
	len = create_modalias(acpi_dev, buf, 1024);
	if (len <= 0)
		return 0;
	buf[len++] = '\n';
	return len;
}
static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL);

static int acpi_eject_operation(acpi_handle handle, int lockable)
{
	struct acpi_object_list arg_list;
	union acpi_object arg;
	acpi_status status = AE_OK;

	/*
	 * TBD: evaluate _PS3?
	 */

	if (lockable) {
		arg_list.count = 1;
		arg_list.pointer = &arg;
		arg.type = ACPI_TYPE_INTEGER;
		arg.integer.value = 0;
		acpi_evaluate_object(handle, "_LCK", &arg_list, NULL);
	}

	arg_list.count = 1;
	arg_list.pointer = &arg;
	arg.type = ACPI_TYPE_INTEGER;
	arg.integer.value = 1;

	/*
	 * TBD: _EJD support.
	 */

	status = acpi_evaluate_object(handle, "_EJ0", &arg_list, NULL);
	if (ACPI_FAILURE(status)) {
		return (-ENODEV);
	}

	return (0);
}

static ssize_t
acpi_eject_store(struct device *d, struct device_attribute *attr,
		const char *buf, size_t count)
{
	int result;
	int ret = count;
	int islockable;
	acpi_status status;
	acpi_handle handle;
	acpi_object_type type = 0;
	struct acpi_device *acpi_device = to_acpi_device(d);

	if ((!count) || (buf[0] != '1')) {
		return -EINVAL;
	}
#ifndef FORCE_EJECT
	if (acpi_device->driver == NULL) {
		ret = -ENODEV;
		goto err;
	}
#endif
	status = acpi_get_type(acpi_device->handle, &type);
	if (ACPI_FAILURE(status) || (!acpi_device->flags.ejectable)) {
		ret = -ENODEV;
		goto err;
	}

	islockable = acpi_device->flags.lockable;
	handle = acpi_device->handle;

	result = acpi_bus_trim(acpi_device, 1);

	if (!result)
		result = acpi_eject_operation(handle, islockable);

	if (result) {
		ret = -EBUSY;
	}
      err:
	return ret;
}

static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);

static ssize_t
acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf) {
	struct acpi_device *acpi_dev = to_acpi_device(dev);

	return sprintf(buf, "%s\n", acpi_dev->pnp.hardware_id);
}
static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);

static ssize_t
acpi_device_path_show(struct device *dev, struct device_attribute *attr, char *buf) {
	struct acpi_device *acpi_dev = to_acpi_device(dev);
	struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
	int result;

	result = acpi_get_name(acpi_dev->handle, ACPI_FULL_PATHNAME, &path);
	if(result)
		goto end;

	result = sprintf(buf, "%s\n", (char*)path.pointer);
	kfree(path.pointer);
  end:
	return result;
}
static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);

static int acpi_device_setup_files(struct acpi_device *dev)
{
	acpi_status status;
	acpi_handle temp;
	int result = 0;

	/*
	 * Devices gotten from FADT don't have a "path" attribute
	 */
	if(dev->handle) {
		result = device_create_file(&dev->dev, &dev_attr_path);
		if(result)
			goto end;
	}

	if(dev->flags.hardware_id) {
		result = device_create_file(&dev->dev, &dev_attr_hid);
		if(result)
			goto end;
	}

	if (dev->flags.hardware_id || dev->flags.compatible_ids){
		result = device_create_file(&dev->dev, &dev_attr_modalias);
		if(result)
			goto end;
	}

        /*
         * If device has _EJ0, 'eject' file is created that is used to trigger
         * hot-removal function from userland.
         */
	status = acpi_get_handle(dev->handle, "_EJ0", &temp);
	if (ACPI_SUCCESS(status))
		result = device_create_file(&dev->dev, &dev_attr_eject);
  end:
	return result;
}

static void acpi_device_remove_files(struct acpi_device *dev)
{
	acpi_status status;
	acpi_handle temp;

	/*
	 * If device has _EJ0, 'eject' file is created that is used to trigger
	 * hot-removal function from userland.
	 */
	status = acpi_get_handle(dev->handle, "_EJ0", &temp);
	if (ACPI_SUCCESS(status))
		device_remove_file(&dev->dev, &dev_attr_eject);

	if (dev->flags.hardware_id || dev->flags.compatible_ids)
		device_remove_file(&dev->dev, &dev_attr_modalias);

	if(dev->flags.hardware_id)
		device_remove_file(&dev->dev, &dev_attr_hid);
	if(dev->handle)
		device_remove_file(&dev->dev, &dev_attr_path);
}
/* --------------------------------------------------------------------------
			ACPI Bus operations
   -------------------------------------------------------------------------- */

int acpi_match_device_ids(struct acpi_device *device,
			  const struct acpi_device_id *ids)
{
	const struct acpi_device_id *id;

	if (device->flags.hardware_id) {
		for (id = ids; id->id[0]; id++) {
			if (!strcmp((char*)id->id, device->pnp.hardware_id))
				return 0;
		}
	}

	if (device->flags.compatible_ids) {
		struct acpi_compatible_id_list *cid_list = device->pnp.cid_list;
		int i;

		for (id = ids; id->id[0]; id++) {
			/* compare multiple _CID entries against driver ids */
			for (i = 0; i < cid_list->count; i++) {
				if (!strcmp((char*)id->id,
					    cid_list->id[i].value))
					return 0;
			}
		}
	}

	return -ENOENT;
}
EXPORT_SYMBOL(acpi_match_device_ids);

static void acpi_device_release(struct device *dev)
{
	struct acpi_device *acpi_dev = to_acpi_device(dev);

	kfree(acpi_dev->pnp.cid_list);
	kfree(acpi_dev);
}

static int acpi_device_suspend(struct device *dev, pm_message_t state)
{
	struct acpi_device *acpi_dev = to_acpi_device(dev);
	struct acpi_driver *acpi_drv = acpi_dev->driver;

	if (acpi_drv && acpi_drv->ops.suspend)
		return acpi_drv->ops.suspend(acpi_dev, state);
	return 0;
}

static int acpi_device_resume(struct device *dev)
{
	struct acpi_device *acpi_dev = to_acpi_device(dev);
	struct acpi_driver *acpi_drv = acpi_dev->driver;

	if (acpi_drv && acpi_drv->ops.resume)
		return acpi_drv->ops.resume(acpi_dev);
	return 0;
}

static int acpi_bus_match(struct device *dev, struct device_driver *drv)
{
	struct acpi_device *acpi_dev = to_acpi_device(dev);
	struct acpi_driver *acpi_drv = to_acpi_driver(drv);

	return !acpi_match_device_ids(acpi_dev, acpi_drv->ids);
}

static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env)
{
	struct acpi_device *acpi_dev = to_acpi_device(dev);
	int len;

	if (add_uevent_var(env, "MODALIAS="))
		return -ENOMEM;
	len = create_modalias(acpi_dev, &env->buf[env->buflen - 1],
			      sizeof(env->buf) - env->buflen);
	if (len >= (sizeof(env->buf) - env->buflen))
		return -ENOMEM;
	env->buflen += len;
	return 0;
}

static int acpi_bus_driver_init(struct acpi_device *, struct acpi_driver *);
static int acpi_start_single_object(struct acpi_device *);
static int acpi_device_probe(struct device * dev)
{
	struct acpi_device *acpi_dev = to_acpi_device(dev);
	struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver);
	int ret;

	ret = acpi_bus_driver_init(acpi_dev, acpi_drv);
	if (!ret) {
		if (acpi_dev->bus_ops.acpi_op_start)
			acpi_start_single_object(acpi_dev);
		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
			"Found driver [%s] for device [%s]\n",
			acpi_drv->name, acpi_dev->pnp.bus_id));
		get_device(dev);
	}
	return ret;
}

static int acpi_device_remove(struct device * dev)
{
	struct acpi_device *acpi_dev = to_acpi_device(dev);
	struct acpi_driver *acpi_drv = acpi_dev->driver;

	if (acpi_drv) {
		if (acpi_drv->ops.stop)
			acpi_drv->ops.stop(acpi_dev, acpi_dev->removal_type);
		if (acpi_drv->ops.remove)
			acpi_drv->ops.remove(acpi_dev, acpi_dev->removal_type);
	}
	acpi_dev->driver = NULL;
	acpi_driver_data(dev) = NULL;

	put_device(dev);
	return 0;
}

static void acpi_device_shutdown(struct device *dev)
{
	struct acpi_device *acpi_dev = to_acpi_device(dev);
	struct acpi_driver *acpi_drv = acpi_dev->driver;

	if (acpi_drv && acpi_drv->ops.shutdown)
		acpi_drv->ops.shutdown(acpi_dev);

	return ;
}

struct bus_type acpi_bus_type = {
	.name		= "acpi",
	.suspend	= acpi_device_suspend,
	.resume		= acpi_device_resume,
	.shutdown	= acpi_device_shutdown,
	.match		= acpi_bus_match,
	.probe		= acpi_device_probe,
	.remove		= acpi_device_remove,
	.uevent		= acpi_device_uevent,
};

static int acpi_device_register(struct acpi_device *device,
				 struct acpi_device *parent)
{
	int result;
	struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id;
	int found = 0;
	/*
	 * Linkage
	 * -------
	 * Link this device to its parent and siblings.
	 */
	INIT_LIST_HEAD(&device->children);
	INIT_LIST_HEAD(&device->node);
	INIT_LIST_HEAD(&device->g_list);
	INIT_LIST_HEAD(&device->wakeup_list);

	new_bus_id = kzalloc(sizeof(struct acpi_device_bus_id), GFP_KERNEL);
	if (!new_bus_id) {
		printk(KERN_ERR PREFIX "Memory allocation error\n");
		return -ENOMEM;
	}

	spin_lock(&acpi_device_lock);
	/*
	 * Find suitable bus_id and instance number in acpi_bus_id_list
	 * If failed, create one and link it into acpi_bus_id_list
	 */
	list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
		if(!strcmp(acpi_device_bus_id->bus_id, device->flags.hardware_id? device->pnp.hardware_id : "device")) {
			acpi_device_bus_id->instance_no ++;
			found = 1;
			kfree(new_bus_id);
			break;
		}
	}
	if(!found) {
		acpi_device_bus_id = new_bus_id;
		strcpy(acpi_device_bus_id->bus_id, device->flags.hardware_id ? device->pnp.hardware_id : "device");
		acpi_device_bus_id->instance_no = 0;
		list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
	}
	sprintf(device->dev.bus_id, "%s:%02x", acpi_device_bus_id->bus_id, acpi_device_bus_id->instance_no);

	if (device->parent) {
		list_add_tail(&device->node, &device->parent->children);
		list_add_tail(&device->g_list, &device->parent->g_list);
	} else
		list_add_tail(&device->g_list, &acpi_device_list);
	if (device->wakeup.flags.valid)
		list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
	spin_unlock(&acpi_device_lock);

	if (device->parent)
		device->dev.parent = &parent->dev;
	device->dev.bus = &acpi_bus_type;
	device_initialize(&device->dev);
	device->dev.release = &acpi_device_release;
	result = device_add(&device->dev);
	if(result) {
		printk("Error adding device %s", device->dev.bus_id);
		goto end;
	}

	result = acpi_device_setup_files(device);
	if(result)
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error creating sysfs interface for device %s\n", device->dev.bus_id));

	device->removal_type = ACPI_BUS_REMOVAL_NORMAL;
	return 0;
  end:
	spin_lock(&acpi_device_lock);
	if (device->parent) {
		list_del(&device->node);
		list_del(&device->g_list);
	} else
		list_del(&device->g_list);
	list_del(&device->wakeup_list);
	spin_unlock(&acpi_device_lock);
	return result;
}

static void acpi_device_unregister(struct acpi_device *device, int type)
{
	spin_lock(&acpi_device_lock);
	if (device->parent) {
		list_del(&device->node);
		list_del(&device->g_list);
	} else
		list_del(&device->g_list);

	list_del(&device->wakeup_list);
	spin_unlock(&acpi_device_lock);

	acpi_detach_data(device->handle, acpi_bus_data_handler);

	acpi_device_remove_files(device);
	device_unregister(&device->dev);
}

/* --------------------------------------------------------------------------
                                 Driver Management
   -------------------------------------------------------------------------- */
/**
 * acpi_bus_driver_init - add a device to a driver