1/* 2 * drivers/media/video/v4l2-int-device.c 3 * 4 * V4L2 internal ioctl interface. 5 * 6 * Copyright (C) 2007 Nokia Corporation. 7 * 8 * Contact: Sakari Ailus <sakari.ailus@nokia.com> 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License 12 * version 2 as published by the Free Software Foundation. 13 * 14 * This program is distributed in the hope that it will be useful, but 15 * WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 17 * General Public License for more details. 18 * 19 * You should have received a copy of the GNU General Public License 20 * along with this program; if not, write to the Free Software 21 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 22 * 02110-1301 USA 23 */ 24 25#include <linux/kernel.h> 26#include <linux/list.h> 27#include <linux/sort.h> 28#include <linux/string.h> 29 30#include <media/v4l2-int-device.h> 31 32static DEFINE_MUTEX(mutex); 33static LIST_HEAD(int_list); 34 35void v4l2_int_device_try_attach_all(void) 36{ 37 struct v4l2_int_device *m, *s; 38 39 list_for_each_entry(m, &int_list, head) { 40 if (m->type != v4l2_int_type_master) 41 continue; 42 43 list_for_each_entry(s, &int_list, head) { 44 if (s->type != v4l2_int_type_slave) 45 continue; 46 47 /* Slave is connected? */ 48 if (s->u.slave->master) 49 continue; 50 51 /* Slave wants to attach to master? */ 52 if (s->u.slave->attach_to[0] != 0 53 && strncmp(m->name, s->u.slave->attach_to, 54 V4L2NAMESIZE)) 55 continue; 56 57 if (!try_module_get(m->module)) 58 continue; 59 60 s->u.slave->master = m; 61 if (m->u.master->attach(s)) { 62 s->u.slave->master = NULL; 63 module_put(m->module); 64 continue; 65 } 66 } 67 } 68} 69EXPORT_SYMBOL_GPL(v4l2_int_device_try_attach_all); 70 71static int ioctl_sort_cmp(const void *a, const void *b) 72{ 73 const struct v4l2_int_ioctl_desc *d1 = a, *d2 = b; 74 75 if (d1->num > d2->num) 76 return 1; 77 78 if (d1->num < d2->num) 79 return -1; 80 81 return 0; 82} 83 84int v4l2_int_device_register(struct v4l2_int_device *d) 85{ 86 if (d->type == v4l2_int_type_slave) 87 sort(d->u.slave->ioctls, d->u.slave->num_ioctls, 88 sizeof(struct v4l2_int_ioctl_desc), 89 &ioctl_sort_cmp, NULL); 90 mutex_lock(&mutex); 91 list_add(&d->head, &int_list); 92 v4l2_int_device_try_attach_all(); 93 mutex_unlock(&mutex); 94 95 return 0; 96} 97EXPORT_SYMBOL_GPL(v4l2_int_device_register); 98 99void v4l2_int_device_unregister(struct v4l2_int_device *d) 100{ 101 mutex_lock(&mutex); 102 list_del(&d->head); 103 if (d->type == v4l2_int_type_slave 104 && d->u.slave->master != NULL) { 105 d->u.slave->master->u.master->detach(d); 106 module_put(d->u.slave->master->module); 107 d->u.slave->master = NULL; 108 } 109 mutex_unlock(&mutex); 110} 111EXPORT_SYMBOL_GPL(v4l2_int_device_unregister); 112 113/* Adapted from search_extable in extable.c. */ 114static v4l2_int_ioctl_func *find_ioctl(struct v4l2_int_slave *slave, int cmd, 115 v4l2_int_ioctl_func *no_such_ioctl) 116{ 117 const struct v4l2_int_ioctl_desc *first = slave->ioctls; 118 const struct v4l2_int_ioctl_desc *last = 119 first + slave->num_ioctls - 1; 120 121 while (first <= last) { 122 const struct v4l2_int_ioctl_desc *mid; 123 124 mid = (last - first) / 2 + first; 125 126 if (mid->num < cmd) 127 first = mid + 1; 128 else if (mid->num > cmd) 129 last = mid - 1; 130 else 131 return mid->func; 132 } 133 134 return no_such_ioctl; 135} 136 137static int no_such_ioctl_0(struct v4l2_int_device *d) 138{ 139 return -ENOIOCTLCMD; 140} 141 142int v4l2_int_ioctl_0(struct v4l2_int_device *d, int cmd) 143{ 144 return ((v4l2_int_ioctl_func_0 *) 145 find_ioctl(d->u.slave, cmd, 146 (v4l2_int_ioctl_func *)no_such_ioctl_0))(d); 147} 148EXPORT_SYMBOL_GPL(v4l2_int_ioctl_0); 149 150static int no_such_ioctl_1(struct v4l2_int_device *d, void *arg) 151{ 152 return -ENOIOCTLCMD; 153} 154 155int v4l2_int_ioctl_1(struct v4l2_int_device *d, int cmd, void *arg) 156{ 157 return ((v4l2_int_ioctl_func_1 *) 158 find_ioctl(d->u.slave, cmd, 159 (v4l2_int_ioctl_func *)no_such_ioctl_1))(d, arg); 160} 161EXPORT_SYMBOL_GPL(v4l2_int_ioctl_1); 162 163MODULE_LICENSE("GPL"); 164