path: root/drivers/acpi/scan.c

/*
 * 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 <linux/signal.h>
#include <linux/kthread.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;
	int count;

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

	len = snprintf(modalias, size, "acpi:");
	size -= len;

	if (acpi_dev->flags.hardware_id) {
		count = snprintf(&modalias[len], size, "%s:",
				 acpi_dev->pnp.hardware_id);
		if (count < 0 || count >= size)
			return -EINVAL;
		len += count;
		size -= count;
	}

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

		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 PREFIX "%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_bus_hot_remove_device(void *context)
{
	struct acpi_device *device;
	acpi_handle handle = context;
	struct acpi_object_list arg_list;
	union acpi_object arg;
	acpi_status status = AE_OK;

	if (acpi_bus_get_device(handle, &device))
		return 0;

	if (!device)
		return 0;

	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
		"Hot-removing device %s...\n", dev_name(&device->dev)));

	if (acpi_bus_trim(device, 1)) {
		printk(KERN_ERR PREFIX
				"Removing device failed\n");
		return -1;
	}

	/* power off device */
	status = acpi_evaluate_object(handle, "_PS3", NULL, NULL);
	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND)
		printk(KERN_WARNING PREFIX
				"Power-off device failed\n");

	if (device->flags.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 ret = count;
	acpi_status status;
	acpi_object_type type = 0;
	struct acpi_device *acpi_device = to_acpi_device(d);
	struct task_struct *task;

	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;
	}

	/* remove the device in another thread to fix the deadlock issue */
	task = kthread_run(acpi_bus_hot_remove_device,
				acpi_device->handle, "acpi_hot_remove_device");
	if (IS_ERR(task))
		ret = PTR_ERR(task);
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(s