Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

Open Menu /drivers/usb/gadget/functions.c 
  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
#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);