include/media/v4l2-subdev.h

   1 /*
   2     V4L2 sub-device support header.
   3
   4     Copyright (C) 2008  Hans Verkuil <hverkuil@xs4all.nl>
   5
   6     This program is free software; you can redistribute it and/or modify
   7     it under the terms of the GNU General Public License as published by
   8     the Free Software Foundation; either version 2 of the License, or
   9     (at your option) any later version.
  10
  11     This program is distributed in the hope that it will be useful,
  12     but WITHOUT ANY WARRANTY; without even the implied warranty of
  13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14     GNU General Public License for more details.
  15
  16     You should have received a copy of the GNU General Public License
  17     along with this program; if not, write to the Free Software
  18     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 #ifndef _V4L2_SUBDEV_H
  22 #define _V4L2_SUBDEV_H
  23
  24 #include <media/v4l2-common.h>
  25
  26 struct v4l2_device;
  27 struct v4l2_subdev;
  28 struct tuner_setup;
  29
  30 /* Sub-devices are devices that are connected somehow to the main bridge
  31    device. These devices are usually audio/video muxers/encoders/decoders or
  32    sensors and webcam controllers.
  33
  34    Usually these devices are controlled through an i2c bus, but other busses
  35    may also be used.
  36
  37    The v4l2_subdev struct provides a way of accessing these devices in a
  38    generic manner. Most operations that these sub-devices support fall in
  39    a few categories: core ops, audio ops, video ops and tuner ops.
  40
  41    More categories can be added if needed, although this should remain a
  42    limited set (no more than approx. 8 categories).
  43
  44    Each category has its own set of ops that subdev drivers can implement.
  45
  46    A subdev driver can leave the pointer to the category ops NULL if
  47    it does not implement them (e.g. an audio subdev will generally not
  48    implement the video category ops). The exception is the core category:
  49    this must always be present.
  50
  51    These ops are all used internally so it is no problem to change, remove
  52    or add ops or move ops from one to another category. Currently these
  53    ops are based on the original ioctls, but since ops are not limited to
  54    one argument there is room for improvement here once all i2c subdev
  55    drivers are converted to use these ops.
  56  */
  57
  58 /* Core ops: it is highly recommended to implement at least these ops:
  59
  60    g_chip_ident
  61    log_status
  62    g_register
  63    s_register
  64
  65    This provides basic debugging support.
  66
  67    The ioctl ops is meant for generic ioctl-like commands. Depending on
  68    the use-case it might be better to use subdev-specific ops (currently
  69    not yet implemented) since ops provide proper type-checking.
  70  */
  71 struct v4l2_subdev_core_ops {
  72         int (*g_chip_ident)(struct v4l2_subdev *sd, struct v4l2_dbg_chip_ident *chip);
  73         int (*log_status)(struct v4l2_subdev *sd);
  74         int (*init)(struct v4l2_subdev *sd, u32 val);
  75         int (*s_standby)(struct v4l2_subdev *sd, u32 standby);
  76         int (*reset)(struct v4l2_subdev *sd, u32 val);
  77         int (*s_gpio)(struct v4l2_subdev *sd, u32 val);
  78         int (*queryctrl)(struct v4l2_subdev *sd, struct v4l2_queryctrl *qc);
  79         int (*g_ctrl)(struct v4l2_subdev *sd, struct v4l2_control *ctrl);
  80         int (*s_ctrl)(struct v4l2_subdev *sd, struct v4l2_control *ctrl);
  81         int (*querymenu)(struct v4l2_subdev *sd, struct v4l2_querymenu *qm);
  82         long (*ioctl)(struct v4l2_subdev *sd, unsigned int cmd, void *arg);
  83 #ifdef CONFIG_VIDEO_ADV_DEBUG
  84         int (*g_register)(struct v4l2_subdev *sd, struct v4l2_dbg_register *reg);
  85         int (*s_register)(struct v4l2_subdev *sd, struct v4l2_dbg_register *reg);
  86 #endif
  87 };
  88
  89 struct v4l2_subdev_tuner_ops {
  90         int (*s_mode)(struct v4l2_subdev *sd, enum v4l2_tuner_type);
  91         int (*s_radio)(struct v4l2_subdev *sd);
  92         int (*s_frequency)(struct v4l2_subdev *sd, struct v4l2_frequency *freq);
  93         int (*g_frequency)(struct v4l2_subdev *sd, struct v4l2_frequency *freq);
  94         int (*g_tuner)(struct v4l2_subdev *sd, struct v4l2_tuner *vt);
  95         int (*s_tuner)(struct v4l2_subdev *sd, struct v4l2_tuner *vt);
  96         int (*s_std)(struct v4l2_subdev *sd, v4l2_std_id norm);
  97         int (*s_type_addr)(struct v4l2_subdev *sd, struct tuner_setup *type);
  98         int (*s_config)(struct v4l2_subdev *sd, const struct v4l2_priv_tun_config *config);
  99 };
 100
 101 struct v4l2_subdev_audio_ops {
 102         int (*s_clock_freq)(struct v4l2_subdev *sd, u32 freq);
 103         int (*s_i2s_clock_freq)(struct v4l2_subdev *sd, u32 freq);
 104         int (*s_routing)(struct v4l2_subdev *sd, const struct v4l2_routing *route);
 105 };
 106
 107 struct v4l2_subdev_video_ops {
 108         int (*s_routing)(struct v4l2_subdev *sd, const struct v4l2_routing *route);
 109         int (*s_crystal_freq)(struct v4l2_subdev *sd, struct v4l2_crystal_freq *freq);
 110         int (*decode_vbi_line)(struct v4l2_subdev *sd, struct v4l2_decode_vbi_line *vbi_line);
 111         int (*s_vbi_data)(struct v4l2_subdev *sd, const struct v4l2_sliced_vbi_data *vbi_data);
 112         int (*g_vbi_data)(struct v4l2_subdev *sd, struct v4l2_sliced_vbi_data *vbi_data);
 113         int (*g_sliced_vbi_cap)(struct v4l2_subdev *sd, struct v4l2_sliced_vbi_cap *cap);
 114         int (*s_std_output)(struct v4l2_subdev *sd, v4l2_std_id std);
 115         int (*s_stream)(struct v4l2_subdev *sd, int enable);
 116         int (*s_fmt)(struct v4l2_subdev *sd, struct v4l2_format *fmt);
 117         int (*g_fmt)(struct v4l2_subdev *sd, struct v4l2_format *fmt);
 118 };
 119
 120 struct v4l2_subdev_ops {
 121         const struct v4l2_subdev_core_ops  *core;
 122         const struct v4l2_subdev_tuner_ops *tuner;
 123         const struct v4l2_subdev_audio_ops *audio;
 124         const struct v4l2_subdev_video_ops *video;
 125 };
 126
 127 #define V4L2_SUBDEV_NAME_SIZE 32
 128
 129 /* Each instance of a subdev driver should create this struct, either
 130    stand-alone or embedded in a larger struct.
 131  */
 132 struct v4l2_subdev {
 133         struct list_head list;
 134         struct module *owner;
 135         struct v4l2_device *dev;
 136         const struct v4l2_subdev_ops *ops;
 137         /* name must be unique */
 138         char name[V4L2_SUBDEV_NAME_SIZE];
 139         /* can be used to group similar subdevs, value is driver-specific */
 140         u32 grp_id;
 141         /* pointer to private data */
 142         void *priv;
 143 };
 144
 145 static inline void v4l2_set_subdevdata(struct v4l2_subdev *sd, void *p)
 146 {
 147         sd->priv = p;
 148 }
 149
 150 static inline void *v4l2_get_subdevdata(const struct v4l2_subdev *sd)
 151 {
 152         return sd->priv;
 153 }
 154
 155 /* Convert an ioctl-type command to the proper v4l2_subdev_ops function call.
 156    This is used by subdev modules that can be called by both old-style ioctl
 157    commands and through the v4l2_subdev_ops.
 158
 159    The ioctl API of the subdev driver can call this function to call the
 160    right ops based on the ioctl cmd and arg.
 161
 162    Once all subdev drivers have been converted and all drivers no longer
 163    use the ioctl interface, then this function can be removed.
 164  */
 165 int v4l2_subdev_command(struct v4l2_subdev *sd, unsigned cmd, void *arg);
 166
 167 static inline void v4l2_subdev_init(struct v4l2_subdev *sd,
 168                                         const struct v4l2_subdev_ops *ops)
 169 {
 170         INIT_LIST_HEAD(&sd->list);
 171         /* ops->core MUST be set */
 172         BUG_ON(!ops || !ops->core);
 173         sd->ops = ops;
 174         sd->dev = NULL;
 175         sd->name[0] = '\0';
 176         sd->grp_id = 0;
 177         sd->priv = NULL;
 178 }
 179
 180 /* Call an ops of a v4l2_subdev, doing the right checks against
 181    NULL pointers.
 182
 183    Example: err = v4l2_subdev_call(sd, core, g_chip_ident, &chip);
 184  */
 185 #define v4l2_subdev_call(sd, o, f, args...)                             \
 186         (!(sd) ? -ENODEV : (((sd) && (sd)->ops->o && (sd)->ops->o->f) ? \
 187                 (sd)->ops->o->f((sd) , ##args) : -ENOIOCTLCMD))
 188
 189 #endif