/* * drivers/media/video/v4l2-int-device.c * * V4L2 internal ioctl interface. * * Copyright (C) 2007 Nokia Corporation. * * Contact: Sakari Ailus <sakari.ailus@nokia.com> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * version 2 as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA * 02110-1301 USA */ #include <linux/kernel.h> #include <linux/list.h> #include <linux/sort.h> #include <linux/string.h> #include <media/v4l2-int-device.h> static DEFINE_MUTEX(mutex); static LIST_HEAD(int_list); static void v4l2_int_device_try_attach_all(void) { struct v4l2_int_device *m, *s; list_for_each_entry(m, &int_list, head) { if (m->type != v4l2_int_type_master) continue; list_for_each_entry(s, &int_list, head) { if (s->type != v4l2_int_type_slave) continue; /* Slave is connected? */ if (s->u.slave->master) continue; /* Slave wants to attach to master? */ if (s->u.slave->attach_to[0] != 0 && strncmp(m->name, s->u.slave->attach_to, V4L2NAMESIZE)) continue; if (!try_module_get(m->module)) continue; if (m->u.master->attach(m, s)) { module_put(m->module); continue; } s->u.slave->master = m; } } } static int ioctl_sort_cmp(const void *a, const void *b) { const struct v4l2_int_ioctl_desc *d1 = a, *d2 = b; if (d1->num > d2->num) return 1; if (d1->num < d2->num) return -1; return 0; } int v4l2_int_device_register(struct v4l2_int_device *d) { if (d->type == v4l2_int_type_slave) sort(d->u.slave->ioctls, d->u.slave->num_ioctls, sizeof(struct v4l2_int_ioctl_desc), &ioctl_sort_cmp, NULL); mutex_lock(&mutex); list_add(&d->head, &int_list); v4l2_int_device_try_attach_all(); mutex_unlock(&mutex); return 0; } EXPORT_SYMBOL_GPL(v4l2_int_device_register); void v4l2_int_device_unregister(struct v4l2_int_device *d) { mutex_lock(&mutex); list_del(&d->head); if (d->type == v4l2_int_type_slave && d->u.slave->master != NULL) { d->u.slave->master->u.master->detach(d); module_put(d->u.slave->master->module); d->u.slave->master = NULL; } mutex_unlock(&mutex); } EXPORT_SYMBOL_GPL(v4l2_int_device_unregister); /* Adapted from search_extable in extable.c. */ static v4l2_int_ioctl_func *find_ioctl(struct v4l2_int_slave *slave, int cmd, v4l2_int_ioctl_func *no_such_ioctl) { const struct v4l2_int_ioctl_desc *first = slave->ioctls; const struct v4l2_int_ioctl_desc *last = first + slave->num_ioctls - 1; while (first <= last) { const struct v4l2_int_ioctl_desc *mid; mid = (last - first) / 2 + first; if (mid->num < cmd) first = mid + 1; else if (mid->num > cmd) last = mid - 1; else return mid->func; } return no_such_ioctl; } static int no_such_ioctl_0(struct v4l2_int_device *d) { return -ENOIOCTLCMD; } int v4l2_int_ioctl_0(struct v4l2_int_device *d, int cmd) { return ((v4l2_int_ioctl_func_0 *) find_ioctl(d->u.slave, cmd, (v4l2_int_ioctl_func *)no_such_ioctl_0))(d); } static int no_such_ioctl_1(struct v4l2_int_device *d, void *arg) { return -ENOIOCTLCMD; } int v4l2_int_ioctl_1(struct v4l2_int_device *d, int cmd, void *arg) { return ((v4l2_int_ioctl_func_1 *) find_ioctl(d->u.slave, cmd, (v4l2_int_ioctl_func *)no_such_ioctl_1))(d, arg); }