diff options
Diffstat (limited to 'drivers/media/video/v4l2-int-device.c')
| -rw-r--r-- | drivers/media/video/v4l2-int-device.c | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/drivers/media/video/v4l2-int-device.c b/drivers/media/video/v4l2-int-device.c new file mode 100644 index 00000000000..8b4ef530a3a --- /dev/null +++ b/drivers/media/video/v4l2-int-device.c @@ -0,0 +1,158 @@ +/* + * 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); +} |