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 /* This is the recommended method to deal with the framerate fields. More
  88    sophisticated drivers will access the fields directly. */
  89 unsigned int
  90 v4l2_video_std_fps(struct v4l2_standard *vs)
  91 {
  92         if (vs->frameperiod.numerator > 0)
  93                 return (((vs->frameperiod.denominator << 8) /
  94                          vs->frameperiod.numerator) +
  95                         (1 << 7)) / (1 << 8);
  96         return 0;
  97 }
  98
  99 /* Fill in the fields of a v4l2_standard structure according to the
 100    'id' and 'transmission' parameters.  Returns negative on error.  */
 101 int v4l2_video_std_construct(struct v4l2_standard *vs,
 102                              int id, char *name)
 103 {
 104         u32 index = vs->index;
 105
 106         memset(vs, 0, sizeof(struct v4l2_standard));
 107         vs->index = index;
 108         vs->id    = id;
 109         if (id & (V4L2_STD_NTSC | V4L2_STD_PAL_M)) {
 110                 vs->frameperiod.numerator = 1001;
 111                 vs->frameperiod.denominator = 30000;
 112                 vs->framelines = 525;
 113         } else {
 114                 vs->frameperiod.numerator = 1;
 115                 vs->frameperiod.denominator = 25;
 116                 vs->framelines = 625;
 117         }
 118         strlcpy(vs->name,name,sizeof(vs->name));
 119         return 0;
 120 }
 121
 122
 123 /* ----------------------------------------------------------------- */
 124 /* priority handling                                                 */
 125
 126 #define V4L2_PRIO_VALID(val) (val == V4L2_PRIORITY_BACKGROUND   || \
 127                               val == V4L2_PRIORITY_INTERACTIVE  || \
 128                               val == V4L2_PRIORITY_RECORD)
 129
 130 int v4l2_prio_init(struct v4l2_prio_state *global)
 131 {
 132         memset(global,0,sizeof(*global));
 133         return 0;
 134 }
 135
 136 int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local,
 137                      enum v4l2_priority new)
 138 {
 139         if (!V4L2_PRIO_VALID(new))
 140                 return -EINVAL;
 141         if (*local == new)
 142                 return 0;
 143
 144         atomic_inc(&global->prios[new]);
 145         if (V4L2_PRIO_VALID(*local))
 146                 atomic_dec(&global->prios[*local]);
 147         *local = new;
 148         return 0;
 149 }
 150
 151 int v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local)
 152 {
 153         return v4l2_prio_change(global,local,V4L2_PRIORITY_DEFAULT);
 154 }
 155
 156 int v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority *local)
 157 {
 158         if (V4L2_PRIO_VALID(*local))
 159                 atomic_dec(&global->prios[*local]);
 160         return 0;
 161 }
 162
 163 enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global)
 164 {
 165         if (atomic_read(&global->prios[V4L2_PRIORITY_RECORD]) > 0)
 166                 return V4L2_PRIORITY_RECORD;
 167         if (atomic_read(&global->prios[V4L2_PRIORITY_INTERACTIVE]) > 0)
 168                 return V4L2_PRIORITY_INTERACTIVE;
 169         if (atomic_read(&global->prios[V4L2_PRIORITY_BACKGROUND]) > 0)
 170                 return V4L2_PRIORITY_BACKGROUND;
 171         return V4L2_PRIORITY_UNSET;
 172 }
 173
 174 int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority *local)
 175 {
 176         if (*local < v4l2_prio_max(global))
 177                 return -EBUSY;
 178         return 0;
 179 }
 180
 181
 182 /* ----------------------------------------------------------------- */
 183 /* some arrays for pretty-printing debug messages                    */
 184
 185 char *v4l2_field_names[] = {
 186         [V4L2_FIELD_ANY]        = "any",
 187         [V4L2_FIELD_NONE]       = "none",
 188         [V4L2_FIELD_TOP]        = "top",
 189         [V4L2_FIELD_BOTTOM]     = "bottom",
 190         [V4L2_FIELD_INTERLACED] = "interlaced",
 191         [V4L2_FIELD_SEQ_TB]     = "seq-tb",
 192         [V4L2_FIELD_SEQ_BT]     = "seq-bt",
 193         [V4L2_FIELD_ALTERNATE]  = "alternate",
 194 };
 195
 196 char *v4l2_type_names[] = {
 197         [V4L2_BUF_TYPE_VIDEO_CAPTURE] = "video-cap",
 198         [V4L2_BUF_TYPE_VIDEO_OVERLAY] = "video-over",
 199         [V4L2_BUF_TYPE_VIDEO_OUTPUT]  = "video-out",
 200         [V4L2_BUF_TYPE_VBI_CAPTURE]   = "vbi-cap",
 201         [V4L2_BUF_TYPE_VBI_OUTPUT]    = "vbi-out",
 202 };
 203
 204 char *v4l2_ioctl_names[256] = {
 205 #if __GNUC__ >= 3
 206         [0 ... 255]                      = "UNKNOWN",
 207 #endif
 208         [_IOC_NR(VIDIOC_QUERYCAP)]       = "VIDIOC_QUERYCAP",
 209         [_IOC_NR(VIDIOC_RESERVED)]       = "VIDIOC_RESERVED",
 210         [_IOC_NR(VIDIOC_ENUM_FMT)]       = "VIDIOC_ENUM_FMT",
 211         [_IOC_NR(VIDIOC_G_FMT)]          = "VIDIOC_G_FMT",
 212         [_IOC_NR(VIDIOC_S_FMT)]          = "VIDIOC_S_FMT",
 213 #if 0
 214         [_IOC_NR(VIDIOC_G_COMP)]         = "VIDIOC_G_COMP",
 215         [_IOC_NR(VIDIOC_S_COMP)]         = "VIDIOC_S_COMP",
 216 #endif
 217         [_IOC_NR(VIDIOC_REQBUFS)]        = "VIDIOC_REQBUFS",
 218         [_IOC_NR(VIDIOC_QUERYBUF)]       = "VIDIOC_QUERYBUF",
 219         [_IOC_NR(VIDIOC_G_FBUF)]         = "VIDIOC_G_FBUF",
 220         [_IOC_NR(VIDIOC_S_FBUF)]         = "VIDIOC_S_FBUF",
 221         [_IOC_NR(VIDIOC_OVERLAY)]        = "VIDIOC_OVERLAY",
 222         [_IOC_NR(VIDIOC_QBUF)]           = "VIDIOC_QBUF",
 223         [_IOC_NR(VIDIOC_DQBUF)]          = "VIDIOC_DQBUF",
 224         [_IOC_NR(VIDIOC_STREAMON)]       = "VIDIOC_STREAMON",
 225         [_IOC_NR(VIDIOC_STREAMOFF)]      = "VIDIOC_STREAMOFF",
 226         [_IOC_NR(VIDIOC_G_PARM)]         = "VIDIOC_G_PARM",
 227         [_IOC_NR(VIDIOC_S_PARM)]         = "VIDIOC_S_PARM",
 228         [_IOC_NR(VIDIOC_G_STD)]          = "VIDIOC_G_STD",
 229         [_IOC_NR(VIDIOC_S_STD)]          = "VIDIOC_S_STD",
 230         [_IOC_NR(VIDIOC_ENUMSTD)]        = "VIDIOC_ENUMSTD",
 231         [_IOC_NR(VIDIOC_ENUMINPUT)]      = "VIDIOC_ENUMINPUT",
 232         [_IOC_NR(VIDIOC_G_CTRL)]         = "VIDIOC_G_CTRL",
 233         [_IOC_NR(VIDIOC_S_CTRL)]         = "VIDIOC_S_CTRL",
 234         [_IOC_NR(VIDIOC_G_TUNER)]        = "VIDIOC_G_TUNER",
 235         [_IOC_NR(VIDIOC_S_TUNER)]        = "VIDIOC_S_TUNER",
 236         [_IOC_NR(VIDIOC_G_AUDIO)]        = "VIDIOC_G_AUDIO",
 237         [_IOC_NR(VIDIOC_S_AUDIO)]        = "VIDIOC_S_AUDIO",
 238         [_IOC_NR(VIDIOC_QUERYCTRL)]      = "VIDIOC_QUERYCTRL",
 239         [_IOC_NR(VIDIOC_QUERYMENU)]      = "VIDIOC_QUERYMENU",
 240         [_IOC_NR(VIDIOC_G_INPUT)]        = "VIDIOC_G_INPUT",
 241         [_IOC_NR(VIDIOC_S_INPUT)]        = "VIDIOC_S_INPUT",
 242         [_IOC_NR(VIDIOC_G_OUTPUT)]       = "VIDIOC_G_OUTPUT",
 243         [_IOC_NR(VIDIOC_S_OUTPUT)]       = "VIDIOC_S_OUTPUT",
 244         [_IOC_NR(VIDIOC_ENUMOUTPUT)]     = "VIDIOC_ENUMOUTPUT",
 245         [_IOC_NR(VIDIOC_G_AUDOUT)]       = "VIDIOC_G_AUDOUT",
 246         [_IOC_NR(VIDIOC_S_AUDOUT)]       = "VIDIOC_S_AUDOUT",
 247         [_IOC_NR(VIDIOC_G_MODULATOR)]    = "VIDIOC_G_MODULATOR",
 248         [_IOC_NR(VIDIOC_S_MODULATOR)]    = "VIDIOC_S_MODULATOR",
 249         [_IOC_NR(VIDIOC_G_FREQUENCY)]    = "VIDIOC_G_FREQUENCY",
 250         [_IOC_NR(VIDIOC_S_FREQUENCY)]    = "VIDIOC_S_FREQUENCY",
 251         [_IOC_NR(VIDIOC_CROPCAP)]        = "VIDIOC_CROPCAP",
 252         [_IOC_NR(VIDIOC_G_CROP)]         = "VIDIOC_G_CROP",
 253         [_IOC_NR(VIDIOC_S_CROP)]         = "VIDIOC_S_CROP",
 254         [_IOC_NR(VIDIOC_G_JPEGCOMP)]     = "VIDIOC_G_JPEGCOMP",
 255         [_IOC_NR(VIDIOC_S_JPEGCOMP)]     = "VIDIOC_S_JPEGCOMP",
 256         [_IOC_NR(VIDIOC_QUERYSTD)]       = "VIDIOC_QUERYSTD",
 257         [_IOC_NR(VIDIOC_TRY_FMT)]        = "VIDIOC_TRY_FMT",
 258 };
 259
 260 /* ----------------------------------------------------------------- */
 261
 262 EXPORT_SYMBOL(v4l2_video_std_fps);
 263 EXPORT_SYMBOL(v4l2_video_std_construct);
 264
 265 EXPORT_SYMBOL(v4l2_prio_init);
 266 EXPORT_SYMBOL(v4l2_prio_change);
 267 EXPORT_SYMBOL(v4l2_prio_open);
 268 EXPORT_SYMBOL(v4l2_prio_close);
 269 EXPORT_SYMBOL(v4l2_prio_max);
 270 EXPORT_SYMBOL(v4l2_prio_check);
 271
 272 EXPORT_SYMBOL(v4l2_field_names);
 273 EXPORT_SYMBOL(v4l2_type_names);
 274 EXPORT_SYMBOL(v4l2_ioctl_names);
 275
 276 /*
 277  * Local variables:
 278  * c-basic-offset: 8
 279  * End:
 280  */