drivers/media/video/v4l2-common.c

   1 /*
   2  *      Video for Linux Two
   3  *
   4  *      A generic video device interface for the LINUX operating system
   5  *      using a set of device structures/vectors for low level operations.
   6  *
   7  *      This file replaces the videodev.c file that comes with the
   8  *      regular kernel distribution.
   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  *      as published by the Free Software Foundation; either version
  13  *      2 of the License, or (at your option) any later version.
  14  *
  15  * Author:      Bill Dirks <bdirks@pacbell.net>
  16  *              based on code by Alan Cox, <alan@cymru.net>
  17  *
  18  */
  19
  20 /*
  21  * Video capture interface for Linux
  22  *
  23  *      A generic video device interface for the LINUX operating system
  24  *      using a set of device structures/vectors for low level operations.
  25  *
  26  *              This program is free software; you can redistribute it and/or
  27  *              modify it under the terms of the GNU General Public License
  28  *              as published by the Free Software Foundation; either version
  29  *              2 of the License, or (at your option) any later version.
  30  *
  31  * Author:      Alan Cox, <alan@redhat.com>
  32  *
  33  * Fixes:
  34  */
  35
  36 /*
  37  * Video4linux 1/2 integration by Justin Schoeman
  38  * <justin@suntiger.ee.up.ac.za>
  39  * 2.4 PROCFS support ported from 2.4 kernels by
  40  *  Iñaki García Etxebarria <garetxe@euskalnet.net>
  41  * Makefile fix by "W. Michael Petullo" <mike@flyn.org>
  42  * 2.4 devfs support ported from 2.4 kernels by
  43  *  Dan Merillat <dan@merillat.org>
  44  * Added Gerd Knorrs v4l1 enhancements (Justin Schoeman)
  45  */
  46
  47 #include <linux/config.h>
  48 #include <linux/module.h>
  49 #include <linux/types.h>
  50 #include <linux/kernel.h>
  51 #include <linux/sched.h>
  52 #include <linux/smp_lock.h>
  53 #include <linux/mm.h>
  54 #include <linux/string.h>
  55 #include <linux/errno.h>
  56 #include <asm/uaccess.h>
  57 #include <asm/system.h>
  58 #include <asm/pgtable.h>
  59 #include <asm/io.h>
  60 #include <asm/div64.h>
  61
  62 #ifdef CONFIG_KMOD
  63 #include <linux/kmod.h>
  64 #endif
  65
  66 #if defined(CONFIG_UST) || defined(CONFIG_UST_MODULE)
  67 #include <linux/ust.h>
  68 #endif
  69
  70
  71 #include <linux/videodev.h>
  72
  73 MODULE_AUTHOR("Bill Dirks, Justin Schoeman, Gerd Knorr");
  74 MODULE_DESCRIPTION("misc helper functions for v4l2 device drivers");
  75 MODULE_LICENSE("GPL");
  76
  77 /*
  78  *
  79  *      V 4 L 2   D R I V E R   H E L P E R   A P I
  80  *
  81  */
  82
  83 /*
  84  *  Video Standard Operations (contributed by Michael Schimek)
  85  */
  86
  87
  88 /* Fill in the fields of a v4l2_standard structure according to the
  89    'id' and 'transmission' parameters.  Returns negative on error.  */
  90 int v4l2_video_std_construct(struct v4l2_standard *vs,
  91                              int id, char *name)
  92 {
  93         u32 index = vs->index;
  94
  95         memset(vs, 0, sizeof(struct v4l2_standard));
  96         vs->index = index;
  97         vs->id    = id;
  98         if (id & (V4L2_STD_NTSC | V4L2_STD_PAL_M)) {
  99                 vs->frameperiod.numerator = 1001;
 100                 vs->frameperiod.denominator = 30000;
 101                 vs->framelines = 525;
 102         } else {
 103                 vs->frameperiod.numerator = 1;
 104                 vs->frameperiod.denominator = 25;
 105                 vs->framelines = 625;
 106         }
 107         strlcpy(vs->name,name,sizeof(vs->name));
 108         return 0;
 109 }
 110
 111
 112 /* ----------------------------------------------------------------- */
 113 /* priority handling                                                 */
 114
 115 #define V4L2_PRIO_VALID(val) (val == V4L2_PRIORITY_BACKGROUND   || \
 116                               val == V4L2_PRIORITY_INTERACTIVE  || \
 117                               val == V4L2_PRIORITY_RECORD)
 118
 119 int v4l2_prio_init(struct v4l2_prio_state *global)
 120 {
 121         memset(global,0,sizeof(*global));
 122         return 0;
 123 }
 124
 125 int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local,
 126                      enum v4l2_priority new)
 127 {
 128         if (!V4L2_PRIO_VALID(new))
 129                 return -EINVAL;
 130         if (*local == new)
 131                 return 0;
 132
 133         atomic_inc(&global->prios[new]);
 134         if (V4L2_PRIO_VALID(*local))
 135                 atomic_dec(&global->prios[*local]);
 136         *local = new;
 137         return 0;
 138 }
 139
 140 int v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local)
 141 {
 142         return v4l2_prio_change(global,local,V4L2_PRIORITY_DEFAULT);
 143 }
 144
 145 int v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority *local)
 146 {
 147         if (V4L2_PRIO_VALID(*local))
 148                 atomic_dec(&global->prios[*local]);
 149         return 0;
 150 }
 151
 152 enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global)
 153 {
 154         if (atomic_read(&global->prios[V4L2_PRIORITY_RECORD]) > 0)
 155                 return V4L2_PRIORITY_RECORD;
 156         if (atomic_read(&global->prios[V4L2_PRIORITY_INTERACTIVE]) > 0)
 157                 return V4L2_PRIORITY_INTERACTIVE;
 158         if (atomic_read(&global->prios[V4L2_PRIORITY_BACKGROUND]) > 0)
 159                 return V4L2_PRIORITY_BACKGROUND;
 160         return V4L2_PRIORITY_UNSET;
 161 }
 162
 163 int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority *local)
 164 {
 165         if (*local < v4l2_prio_max(global))
 166                 return -EBUSY;
 167         return 0;
 168 }
 169
 170
 171 /* ----------------------------------------------------------------- */
 172 /* some arrays for pretty-printing debug messages                    */
 173
 174 char *v4l2_field_names[] = {
 175         [V4L2_FIELD_ANY]        = "any",
 176         [V4L2_FIELD_NONE]       = "none",
 177         [V4L2_FIELD_TOP]        = "top",
 178         [V4L2_FIELD_BOTTOM]     = "bottom",
 179         [V4L2_FIELD_INTERLACED] = "interlaced",
 180         [V4L2_FIELD_SEQ_TB]     = "seq-tb",
 181         [V4L2_FIELD_SEQ_BT]     = "seq-bt",
 182         [V4L2_FIELD_ALTERNATE]  = "alternate",
 183 };
 184
 185 char *v4l2_type_names[] = {
 186         [V4L2_BUF_TYPE_VIDEO_CAPTURE] = "video-cap",
 187         [V4L2_BUF_TYPE_VIDEO_OVERLAY] = "video-over",
 188         [V4L2_BUF_TYPE_VIDEO_OUTPUT]  = "video-out",
 189         [V4L2_BUF_TYPE_VBI_CAPTURE]   = "vbi-cap",
 190         [V4L2_BUF_TYPE_VBI_OUTPUT]    = "vbi-out",
 191 };
 192
 193 char *v4l2_ioctl_names[256] = {
 194 #if __GNUC__ >= 3
 195         [0 ... 255]                      = "UNKNOWN",
 196 #endif
 197         [_IOC_NR(VIDIOC_QUERYCAP)]       = "VIDIOC_QUERYCAP",
 198         [_IOC_NR(VIDIOC_RESERVED)]       = "VIDIOC_RESERVED",
 199         [_IOC_NR(VIDIOC_ENUM_FMT)]       = "VIDIOC_ENUM_FMT",
 200         [_IOC_NR(VIDIOC_G_FMT)]          = "VIDIOC_G_FMT",
 201         [_IOC_NR(VIDIOC_S_FMT)]          = "VIDIOC_S_FMT",
 202         [_IOC_NR(VIDIOC_REQBUFS)]        = "VIDIOC_REQBUFS",
 203         [_IOC_NR(VIDIOC_QUERYBUF)]       = "VIDIOC_QUERYBUF",
 204         [_IOC_NR(VIDIOC_G_FBUF)]         = "VIDIOC_G_FBUF",
 205         [_IOC_NR(VIDIOC_S_FBUF)]         = "VIDIOC_S_FBUF",
 206         [_IOC_NR(VIDIOC_OVERLAY)]        = "VIDIOC_OVERLAY",
 207         [_IOC_NR(VIDIOC_QBUF)]           = "VIDIOC_QBUF",
 208         [_IOC_NR(VIDIOC_DQBUF)]          = "VIDIOC_DQBUF",
 209         [_IOC_NR(VIDIOC_STREAMON)]       = "VIDIOC_STREAMON",
 210         [_IOC_NR(VIDIOC_STREAMOFF)]      = "VIDIOC_STREAMOFF",
 211         [_IOC_NR(VIDIOC_G_PARM)]         = "VIDIOC_G_PARM",
 212         [_IOC_NR(VIDIOC_S_PARM)]         = "VIDIOC_S_PARM",
 213         [_IOC_NR(VIDIOC_G_STD)]          = "VIDIOC_G_STD",
 214         [_IOC_NR(VIDIOC_S_STD)]          = "VIDIOC_S_STD",
 215         [_IOC_NR(VIDIOC_ENUMSTD)]        = "VIDIOC_ENUMSTD",
 216         [_IOC_NR(VIDIOC_ENUMINPUT)]      = "VIDIOC_ENUMINPUT",
 217         [_IOC_NR(VIDIOC_G_CTRL)]         = "VIDIOC_G_CTRL",
 218         [_IOC_NR(VIDIOC_S_CTRL)]         = "VIDIOC_S_CTRL",
 219         [_IOC_NR(VIDIOC_G_TUNER)]        = "VIDIOC_G_TUNER",
 220         [_IOC_NR(VIDIOC_S_TUNER)]        = "VIDIOC_S_TUNER",
 221         [_IOC_NR(VIDIOC_G_AUDIO)]        = "VIDIOC_G_AUDIO",
 222         [_IOC_NR(VIDIOC_S_AUDIO)]        = "VIDIOC_S_AUDIO",
 223         [_IOC_NR(VIDIOC_QUERYCTRL)]      = "VIDIOC_QUERYCTRL",
 224         [_IOC_NR(VIDIOC_QUERYMENU)]      = "VIDIOC_QUERYMENU",
 225         [_IOC_NR(VIDIOC_G_INPUT)]        = "VIDIOC_G_INPUT",
 226         [_IOC_NR(VIDIOC_S_INPUT)]        = "VIDIOC_S_INPUT",
 227         [_IOC_NR(VIDIOC_G_OUTPUT)]       = "VIDIOC_G_OUTPUT",
 228         [_IOC_NR(VIDIOC_S_OUTPUT)]       = "VIDIOC_S_OUTPUT",
 229         [_IOC_NR(VIDIOC_ENUMOUTPUT)]     = "VIDIOC_ENUMOUTPUT",
 230         [_IOC_NR(VIDIOC_G_AUDOUT)]       = "VIDIOC_G_AUDOUT",
 231         [_IOC_NR(VIDIOC_S_AUDOUT)]       = "VIDIOC_S_AUDOUT",
 232         [_IOC_NR(VIDIOC_G_MODULATOR)]    = "VIDIOC_G_MODULATOR",
 233         [_IOC_NR(VIDIOC_S_MODULATOR)]    = "VIDIOC_S_MODULATOR",
 234         [_IOC_NR(VIDIOC_G_FREQUENCY)]    = "VIDIOC_G_FREQUENCY",
 235         [_IOC_NR(VIDIOC_S_FREQUENCY)]    = "VIDIOC_S_FREQUENCY",
 236         [_IOC_NR(VIDIOC_CROPCAP)]        = "VIDIOC_CROPCAP",
 237         [_IOC_NR(VIDIOC_G_CROP)]         = "VIDIOC_G_CROP",
 238         [_IOC_NR(VIDIOC_S_CROP)]         = "VIDIOC_S_CROP",
 239         [_IOC_NR(VIDIOC_G_JPEGCOMP)]     = "VIDIOC_G_JPEGCOMP",
 240         [_IOC_NR(VIDIOC_S_JPEGCOMP)]     = "VIDIOC_S_JPEGCOMP",
 241         [_IOC_NR(VIDIOC_QUERYSTD)]       = "VIDIOC_QUERYSTD",
 242         [_IOC_NR(VIDIOC_TRY_FMT)]        = "VIDIOC_TRY_FMT",
 243 };
 244
 245 /* ----------------------------------------------------------------- */
 246
 247 EXPORT_SYMBOL(v4l2_video_std_construct);
 248
 249 EXPORT_SYMBOL(v4l2_prio_init);
 250 EXPORT_SYMBOL(v4l2_prio_change);
 251 EXPORT_SYMBOL(v4l2_prio_open);
 252 EXPORT_SYMBOL(v4l2_prio_close);
 253 EXPORT_SYMBOL(v4l2_prio_max);
 254 EXPORT_SYMBOL(v4l2_prio_check);
 255
 256 EXPORT_SYMBOL(v4l2_field_names);
 257 EXPORT_SYMBOL(v4l2_type_names);
 258 EXPORT_SYMBOL(v4l2_ioctl_names);
 259
 260 /*
 261  * Local variables:
 262  * c-basic-offset: 8
 263  * End:
 264  */