pci_hotplug_core.c

audio driver for hotplug pci on linux 2.6.27

	.attr = {.name = "test", .mode = S_IFREG | S_IRUGO | S_IWUSR},
	.store = test_write_file
};

static int has_power_file(struct pci_slot *pci_slot)
{
	struct hotplug_slot *slot = pci_slot->hotplug;
	if ((!slot) || (!slot->ops))
		return -ENODEV;
	if ((slot->ops->enable_slot) ||
	    (slot->ops->disable_slot) ||
	    (slot->ops->get_power_status))
		return 0;
	return -ENOENT;
}

static int has_attention_file(struct pci_slot *pci_slot)
{
	struct hotplug_slot *slot = pci_slot->hotplug;
	if ((!slot) || (!slot->ops))
		return -ENODEV;
	if ((slot->ops->set_attention_status) ||
	    (slot->ops->get_attention_status))
		return 0;
	return -ENOENT;
}

static int has_latch_file(struct pci_slot *pci_slot)
{
	struct hotplug_slot *slot = pci_slot->hotplug;
	if ((!slot) || (!slot->ops))
		return -ENODEV;
	if (slot->ops->get_latch_status)
		return 0;
	return -ENOENT;
}

static int has_adapter_file(struct pci_slot *pci_slot)
{
	struct hotplug_slot *slot = pci_slot->hotplug;
	if ((!slot) || (!slot->ops))
		return -ENODEV;
	if (slot->ops->get_adapter_status)
		return 0;
	return -ENOENT;
}

static int has_max_bus_speed_file(struct pci_slot *pci_slot)
{
	struct hotplug_slot *slot = pci_slot->hotplug;
	if ((!slot) || (!slot->ops))
		return -ENODEV;
	if (slot->ops->get_max_bus_speed)
		return 0;
	return -ENOENT;
}

static int has_cur_bus_speed_file(struct pci_slot *pci_slot)
{
	struct hotplug_slot *slot = pci_slot->hotplug;
	if ((!slot) || (!slot->ops))
		return -ENODEV;
	if (slot->ops->get_cur_bus_speed)
		return 0;
	return -ENOENT;
}

static int has_test_file(struct pci_slot *pci_slot)
{
	struct hotplug_slot *slot = pci_slot->hotplug;
	if ((!slot) || (!slot->ops))
		return -ENODEV;
	if (slot->ops->hardware_test)
		return 0;
	return -ENOENT;
}

static int fs_add_slot(struct pci_slot *slot)
{
	int retval = 0;

	if (has_power_file(slot) == 0) {
		retval = sysfs_create_file(&slot->kobj, &hotplug_slot_attr_power.attr);
		if (retval)
			goto exit_power;
	}

	if (has_attention_file(slot) == 0) {
		retval = sysfs_create_file(&slot->kobj,
					   &hotplug_slot_attr_attention.attr);
		if (retval)
			goto exit_attention;
	}

	if (has_latch_file(slot) == 0) {
		retval = sysfs_create_file(&slot->kobj,
					   &hotplug_slot_attr_latch.attr);
		if (retval)
			goto exit_latch;
	}

	if (has_adapter_file(slot) == 0) {
		retval = sysfs_create_file(&slot->kobj,
					   &hotplug_slot_attr_presence.attr);
		if (retval)
			goto exit_adapter;
	}

	if (has_max_bus_speed_file(slot) == 0) {
		retval = sysfs_create_file(&slot->kobj,
					   &hotplug_slot_attr_max_bus_speed.attr);
		if (retval)
			goto exit_max_speed;
	}

	if (has_cur_bus_speed_file(slot) == 0) {
		retval = sysfs_create_file(&slot->kobj,
					   &hotplug_slot_attr_cur_bus_speed.attr);
		if (retval)
			goto exit_cur_speed;
	}

	if (has_test_file(slot) == 0) {
		retval = sysfs_create_file(&slot->kobj,
					   &hotplug_slot_attr_test.attr);
		if (retval)
			goto exit_test;
	}

	goto exit;

exit_test:
	if (has_cur_bus_speed_file(slot) == 0)
		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_cur_bus_speed.attr);

exit_cur_speed:
	if (has_max_bus_speed_file(slot) == 0)
		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_max_bus_speed.attr);

exit_max_speed:
	if (has_adapter_file(slot) == 0)
		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_presence.attr);

exit_adapter:
	if (has_latch_file(slot) == 0)
		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_latch.attr);

exit_latch:
	if (has_attention_file(slot) == 0)
		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_attention.attr);

exit_attention:
	if (has_power_file(slot) == 0)
		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_power.attr);
exit_power:
exit:
	return retval;
}

static void fs_remove_slot(struct pci_slot *slot)
{
	if (has_power_file(slot) == 0)
		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_power.attr);

	if (has_attention_file(slot) == 0)
		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_attention.attr);

	if (has_latch_file(slot) == 0)
		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_latch.attr);

	if (has_adapter_file(slot) == 0)
		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_presence.attr);

	if (has_max_bus_speed_file(slot) == 0)
		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_max_bus_speed.attr);

	if (has_cur_bus_speed_file(slot) == 0)
		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_cur_bus_speed.attr);

	if (has_test_file(slot) == 0)
		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_test.attr);
}

static struct hotplug_slot *get_slot_from_name (const char *name)
{
	struct hotplug_slot *slot;
	struct list_head *tmp;

	list_for_each (tmp, &pci_hotplug_slot_list) {
		slot = list_entry (tmp, struct hotplug_slot, slot_list);
		if (strcmp(hotplug_slot_name(slot), name) == 0)
			return slot;
	}
	return NULL;
}

/**
 * pci_hp_register - register a hotplug_slot with the PCI hotplug subsystem
 * @bus: bus this slot is on
 * @slot: pointer to the &struct hotplug_slot to register
 * @slot_nr: slot number
 * @name: name registered with kobject core
 *
 * Registers a hotplug slot with the pci hotplug subsystem, which will allow
 * userspace interaction to the slot.
 *
 * Returns 0 if successful, anything else for an error.
 */
int pci_hp_register(struct hotplug_slot *slot, struct pci_bus *bus, int slot_nr,
			const char *name)
{
	int result;
	struct pci_slot *pci_slot;

	if (slot == NULL)
		return -ENODEV;
	if ((slot->info == NULL) || (slot->ops == NULL))
		return -EINVAL;
	if (slot->release == NULL) {
		dbg("Why are you trying to register a hotplug slot "
		    "without a proper release function?\n");
		return -EINVAL;
	}

	mutex_lock(&pci_hp_mutex);

	/*
	 * No problems if we call this interface from both ACPI_PCI_SLOT
	 * driver and call it here again. If we've already created the
	 * pci_slot, the interface will simply bump the refcount.
	 */
	pci_slot = pci_create_slot(bus, slot_nr, name, slot);
	if (IS_ERR(pci_slot)) {
		result = PTR_ERR(pci_slot);
		goto out;
	}

	slot->pci_slot = pci_slot;
	pci_slot->hotplug = slot;

	list_add(&slot->slot_list, &pci_hotplug_slot_list);

	result = fs_add_slot(pci_slot);
	kobject_uevent(&pci_slot->kobj, KOBJ_ADD);
	dbg("Added slot %s to the list\n", name);
out:
	mutex_unlock(&pci_hp_mutex);
	return result;
}

/**
 * pci_hp_deregister - deregister a hotplug_slot with the PCI hotplug subsystem
 * @hotplug: pointer to the &struct hotplug_slot to deregister
 *
 * The @slot must have been registered with the pci hotplug subsystem
 * previously with a call to pci_hp_register().
 *
 * Returns 0 if successful, anything else for an error.
 */
int pci_hp_deregister(struct hotplug_slot *hotplug)
{
	struct hotplug_slot *temp;
	struct pci_slot *slot;

	if (!hotplug)
		return -ENODEV;

	mutex_lock(&pci_hp_mutex);
	temp = get_slot_from_name(hotplug_slot_name(hotplug));
	if (temp != hotplug) {
		mutex_unlock(&pci_hp_mutex);
		return -ENODEV;
	}

	list_del(&hotplug->slot_list);

	slot = hotplug->pci_slot;
	fs_remove_slot(slot);
	dbg("Removed slot %s from the list\n", hotplug_slot_name(hotplug));

	hotplug->release(hotplug);
	slot->hotplug = NULL;
	pci_destroy_slot(slot);
	mutex_unlock(&pci_hp_mutex);

	return 0;
}

/**
 * pci_hp_change_slot_info - changes the slot's information structure in the core
 * @hotplug: pointer to the slot whose info has changed
 * @info: pointer to the info copy into the slot's info structure
 *
 * @slot must have been registered with the pci 
 * hotplug subsystem previously with a call to pci_hp_register().
 *
 * Returns 0 if successful, anything else for an error.
 */
int __must_check pci_hp_change_slot_info(struct hotplug_slot *hotplug,
					 struct hotplug_slot_info *info)
{
	struct pci_slot *slot;
	if (!hotplug || !info)
		return -ENODEV;
	slot = hotplug->pci_slot;

	memcpy(hotplug->info, info, sizeof(struct hotplug_slot_info));

	return 0;
}

static int __init pci_hotplug_init (void)
{
	int result;

	result = cpci_hotplug_init(debug);
	if (result) {
		err ("cpci_hotplug_init with error %d\n", result);
		goto err_cpci;
	}

	info (DRIVER_DESC " version: " DRIVER_VERSION "\n");

err_cpci:
	return result;
}

static void __exit pci_hotplug_exit (void)
{
	cpci_hotplug_exit();
}

module_init(pci_hotplug_init);
module_exit(pci_hotplug_exit);

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
module_param(debug, bool, 0644);
MODULE_PARM_DESC(debug, "Debugging mode enabled or not");

EXPORT_SYMBOL_GPL(pci_hp_register);
EXPORT_SYMBOL_GPL(pci_hp_deregister);
EXPORT_SYMBOL_GPL(pci_hp_change_slot_info);