#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/err.h>

#include <linux/usb/composite.h>

static LIST_HEAD(func_list);
static DEFINE_MUTEX(func_lock);

static struct usb_function_instance *try_get_usb_function_instance(const char *name)
{
	struct usb_function_driver *fd;
	struct usb_function_instance *fi;

	fi = ERR_PTR(-ENOENT);
	mutex_lock(&func_lock);
	list_for_each_entry(fd, &func_list, list) {

		if (strcmp(name, fd->name))
			continue;

		if (!try_module_get(fd->mod)) {
			fi = ERR_PTR(-EBUSY);
			break;
		}
		fi = fd->alloc_inst();
		if (IS_ERR(fi))
			module_put(fd->mod);
		else
			fi->fd = fd;
		break;
	}
	mutex_unlock(&func_lock);
	return fi;
}

struct usb_function_instance *usb_get_function_instance(const char *name)
{
	struct usb_function_instance *fi;
	int ret;

	fi = try_get_usb_function_instance(name);
	if (!IS_ERR(fi))
		return fi;
	ret = PTR_ERR(fi);
	if (ret != -ENOENT)
		return fi;
	ret = request_module("usbfunc:%s", name);
	if (ret < 0)
		return ERR_PTR(ret);
	return try_get_usb_function_instance(name);
}
EXPORT_SYMBOL_GPL(usb_get_function_instance);

struct usb_function *usb_get_function(struct usb_function_instance *fi)
{
	struct usb_function *f;

	f = fi->fd->alloc_func(fi);
	if (IS_ERR(f))
		return f;
	f->fi = fi;
	return f;
}
EXPORT_SYMBOL_GPL(usb_get_function);

void usb_put_function_instance(struct usb_function_instance *fi)
{
	struct module *mod;

	if (!fi)
		return;

	mod = fi->fd->mod;
	fi->free_func_inst(fi);
	module_put(mod);
}
EXPORT_SYMBOL_GPL(usb_put_function_instance);

void usb_put_function(struct usb_function *f)
{
	if (!f)
		return;

	f->free_func(f);
}
EXPORT_SYMBOL_GPL(usb_put_function);

int usb_function_register(struct usb_function_driver *newf)
{
	struct usb_function_driver *fd;
	int ret;

	ret = -EEXIST;

	mutex_lock(&func_lock);
	list_for_each_entry(fd, &func_list, list) {
		if (!strcmp(fd->name, newf->name))
			goto out;
	}
	ret = 0;
	list_add_tail(&newf->list, &func_list);
out:
	mutex_unlock(&func_lock);
	return ret;
}
EXPORT_SYMBOL_GPL(usb_function_register);

void usb_function_unregister(struct usb_function_driver *fd)
{
	mutex_lock(&func_lock);
	list_del(&fd->list);
	mutex_unlock(&func_lock);
}
EXPORT_SYMBOL_GPL(usb_function_unregister);
'form'><form class='right' method='get' action='/cgit.cgi/linux/net-next.git/log/drivers/usb/serial/ch341.c'>
<input type='hidden' name='h' value='nds-private-remove'/><input type='hidden' name='id' value='3efa70d78f218e4c9276b0bac0545e5184c1c47b'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=3efa70d78f218e4c9276b0bac0545e5184c1c47b'>root</a>/<a href='/cgit.cgi/linux/net-next.git/diff/drivers?h=nds-private-remove&amp;id=3efa70d78f218e4c9276b0bac0545e5184c1c47b'>drivers</a>/<a href='/cgit.cgi/linux/net-next.git/diff/drivers/usb?h=nds-private-remove&amp;id=3efa70d78f218e4c9276b0bac0545e5184c1c47b'>usb</a>/<a href='/cgit.cgi/linux/net-next.git/diff/drivers/usb/serial?h=nds-private-remove&amp;id=3efa70d78f218e4c9276b0bac0545e5184c1c47b'>serial</a>/<a href='/cgit.cgi/linux/net-next.git/diff/drivers/usb/serial/ch341.c?h=nds-private-remove&amp;id=3efa70d78f218e4c9276b0bac0545e5184c1c47b'>ch341.c</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='h' value='nds-private-remove'/><input type='hidden' name='id' value='3efa70d78f218e4c9276b0bac0545e5184c1c47b'/><table><tr><td colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=3efa70d78f218e4c9276b0bac0545e5184c1c47b'>Diffstat</a> (limited to 'drivers/usb/serial/ch341.c')</div><table summary='diffstat' class='diffstat'>