include/media/v4l2-async.h

   1 /*
   2  * V4L2 asynchronous subdevice registration API
   3  *
   4  * Copyright (C) 2012-2013, Guennadi Liakhovetski <g.liakhovetski@gmx.de>
   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 version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10
  11 #ifndef V4L2_ASYNC_H
  12 #define V4L2_ASYNC_H
  13
  14 #include <linux/list.h>
  15 #include <linux/mutex.h>
  16
  17 struct device;
  18 struct device_node;
  19 struct v4l2_device;
  20 struct v4l2_subdev;
  21 struct v4l2_async_notifier;
  22
  23 /**
  24  * enum v4l2_async_match_type - type of asynchronous subdevice logic to be used
  25  *      in order to identify a match
  26  *
  27  * @V4L2_ASYNC_MATCH_CUSTOM: Match will use the logic provided by &struct
  28  *      v4l2_async_subdev.match ops
  29  * @V4L2_ASYNC_MATCH_DEVNAME: Match will use the device name
  30  * @V4L2_ASYNC_MATCH_I2C: Match will check for I2C adapter ID and address
  31  * @V4L2_ASYNC_MATCH_FWNODE: Match will use firmware node
  32  *
  33  * This enum is used by the asyncrhronous sub-device logic to define the
  34  * algorithm that will be used to match an asynchronous device.
  35  */
  36 enum v4l2_async_match_type {
  37         V4L2_ASYNC_MATCH_CUSTOM,
  38         V4L2_ASYNC_MATCH_DEVNAME,
  39         V4L2_ASYNC_MATCH_I2C,
  40         V4L2_ASYNC_MATCH_FWNODE,
  41 };
  42
  43 /**
  44  * struct v4l2_async_subdev - sub-device descriptor, as known to a bridge
  45  *
  46  * @match_type: type of match that will be used
  47  * @match:      union of per-bus type matching data sets
  48  * @match.fwnode:
  49  *              pointer to &struct fwnode_handle to be matched.
  50  *              Used if @match_type is %V4L2_ASYNC_MATCH_FWNODE.
  51  * @match.device_name:
  52  *              string containing the device name to be matched.
  53  *              Used if @match_type is %V4L2_ASYNC_MATCH_DEVNAME.
  54  * @match.i2c:  embedded struct with I2C parameters to be matched.
  55  *              Both @match.i2c.adapter_id and @match.i2c.address
  56  *              should be matched.
  57  *              Used if @match_type is %V4L2_ASYNC_MATCH_I2C.
  58  * @match.i2c.adapter_id:
  59  *              I2C adapter ID to be matched.
  60  *              Used if @match_type is %V4L2_ASYNC_MATCH_I2C.
  61  * @match.i2c.address:
  62  *              I2C address to be matched.
  63  *              Used if @match_type is %V4L2_ASYNC_MATCH_I2C.
  64  * @match.custom:
  65  *              Driver-specific match criteria.
  66  *              Used if @match_type is %V4L2_ASYNC_MATCH_CUSTOM.
  67  * @match.custom.match:
  68  *              Driver-specific match function to be used if
  69  *              %V4L2_ASYNC_MATCH_CUSTOM.
  70  * @match.custom.priv:
  71  *              Driver-specific private struct with match parameters
  72  *              to be used if %V4L2_ASYNC_MATCH_CUSTOM.
  73  * @asd_list:   used to add struct v4l2_async_subdev objects to the
  74  *              master notifier @asd_list
  75  * @list:       used to link struct v4l2_async_subdev objects, waiting to be
  76  *              probed, to a notifier->waiting list
  77  *
  78  * When this struct is used as a member in a driver specific struct,
  79  * the driver specific struct shall contain the &struct
  80  * v4l2_async_subdev as its first member.
  81  */
  82 struct v4l2_async_subdev {
  83         enum v4l2_async_match_type match_type;
  84         union {
  85                 struct fwnode_handle *fwnode;
  86                 const char *device_name;
  87                 struct {
  88                         int adapter_id;
  89                         unsigned short address;
  90                 } i2c;
  91                 struct {
  92                         bool (*match)(struct device *dev,
  93                                       struct v4l2_async_subdev *sd);
  94                         void *priv;
  95                 } custom;
  96         } match;
  97
  98         /* v4l2-async core private: not to be used by drivers */
  99         struct list_head list;
 100         struct list_head asd_list;
 101 };
 102
 103 /**
 104  * struct v4l2_async_notifier_operations - Asynchronous V4L2 notifier operations
 105  * @bound:      a subdevice driver has successfully probed one of the subdevices
 106  * @complete:   All subdevices have been probed successfully. The complete
 107  *              callback is only executed for the root notifier.
 108  * @unbind:     a subdevice is leaving
 109  */
 110 struct v4l2_async_notifier_operations {
 111         int (*bound)(struct v4l2_async_notifier *notifier,
 112                      struct v4l2_subdev *subdev,
 113                      struct v4l2_async_subdev *asd);
 114         int (*complete)(struct v4l2_async_notifier *notifier);
 115         void (*unbind)(struct v4l2_async_notifier *notifier,
 116                        struct v4l2_subdev *subdev,
 117                        struct v4l2_async_subdev *asd);
 118 };
 119
 120 /**
 121  * struct v4l2_async_notifier - v4l2_device notifier data
 122  *
 123  * @ops:        notifier operations
 124  * @v4l2_dev:   v4l2_device of the root notifier, NULL otherwise
 125  * @sd:         sub-device that registered the notifier, NULL otherwise
 126  * @parent:     parent notifier
 127  * @asd_list:   master list of struct v4l2_async_subdev
 128  * @waiting:    list of struct v4l2_async_subdev, waiting for their drivers
 129  * @done:       list of struct v4l2_subdev, already probed
 130  * @list:       member in a global list of notifiers
 131  */
 132 struct v4l2_async_notifier {
 133         const struct v4l2_async_notifier_operations *ops;
 134         struct v4l2_device *v4l2_dev;
 135         struct v4l2_subdev *sd;
 136         struct v4l2_async_notifier *parent;
 137         struct list_head asd_list;
 138         struct list_head waiting;
 139         struct list_head done;
 140         struct list_head list;
 141 };
 142
 143 /**
 144  * v4l2_async_notifier_init - Initialize a notifier.
 145  *
 146  * @notifier: pointer to &struct v4l2_async_notifier
 147  *
 148  * This function initializes the notifier @asd_list. It must be called
 149  * before the first call to @v4l2_async_notifier_add_subdev.
 150  */
 151 void v4l2_async_notifier_init(struct v4l2_async_notifier *notifier);
 152
 153 /**
 154  * v4l2_async_notifier_add_subdev - Add an async subdev to the
 155  *                              notifier's master asd list.
 156  *
 157  * @notifier: pointer to &struct v4l2_async_notifier
 158  * @asd: pointer to &struct v4l2_async_subdev
 159  *
 160  * Call this function before registering a notifier to link the
 161  * provided asd to the notifiers master @asd_list.
 162  */
 163 int v4l2_async_notifier_add_subdev(struct v4l2_async_notifier *notifier,
 164                                    struct v4l2_async_subdev *asd);
 165
 166 /**
 167  * v4l2_async_notifier_add_fwnode_subdev - Allocate and add a fwnode async
 168  *                              subdev to the notifier's master asd_list.
 169  *
 170  * @notifier: pointer to &struct v4l2_async_notifier
 171  * @fwnode: fwnode handle of the sub-device to be matched
 172  * @asd_struct_size: size of the driver's async sub-device struct, including
 173  *                   sizeof(struct v4l2_async_subdev). The &struct
 174  *                   v4l2_async_subdev shall be the first member of
 175  *                   the driver's async sub-device struct, i.e. both
 176  *                   begin at the same memory address.
 177  *
 178  * Allocate a fwnode-matched asd of size asd_struct_size, and add it
 179  * to the notifiers @asd_list.
 180  */
 181 struct v4l2_async_subdev *
 182 v4l2_async_notifier_add_fwnode_subdev(struct v4l2_async_notifier *notifier,
 183                                       struct fwnode_handle *fwnode,
 184                                       unsigned int asd_struct_size);
 185
 186 /**
 187  * v4l2_async_notifier_add_i2c_subdev - Allocate and add an i2c async
 188  *                              subdev to the notifier's master asd_list.
 189  *
 190  * @notifier: pointer to &struct v4l2_async_notifier
 191  * @adapter_id: I2C adapter ID to be matched
 192  * @address: I2C address of sub-device to be matched
 193  * @asd_struct_size: size of the driver's async sub-device struct, including
 194  *                   sizeof(struct v4l2_async_subdev). The &struct
 195  *                   v4l2_async_subdev shall be the first member of
 196  *                   the driver's async sub-device struct, i.e. both
 197  *                   begin at the same memory address.
 198  *
 199  * Same as above but for I2C matched sub-devices.
 200  */
 201 struct v4l2_async_subdev *
 202 v4l2_async_notifier_add_i2c_subdev(struct v4l2_async_notifier *notifier,
 203                                    int adapter_id, unsigned short address,
 204                                    unsigned int asd_struct_size);
 205
 206 /**
 207  * v4l2_async_notifier_add_devname_subdev - Allocate and add a device-name
 208  *                              async subdev to the notifier's master asd_list.
 209  *
 210  * @notifier: pointer to &struct v4l2_async_notifier
 211  * @device_name: device name string to be matched
 212  * @asd_struct_size: size of the driver's async sub-device struct, including
 213  *                   sizeof(struct v4l2_async_subdev). The &struct
 214  *                   v4l2_async_subdev shall be the first member of
 215  *                   the driver's async sub-device struct, i.e. both
 216  *                   begin at the same memory address.
 217  *
 218  * Same as above but for device-name matched sub-devices.
 219  */
 220 struct v4l2_async_subdev *
 221 v4l2_async_notifier_add_devname_subdev(struct v4l2_async_notifier *notifier,
 222                                        const char *device_name,
 223                                        unsigned int asd_struct_size);
 224
 225 /**
 226  * v4l2_async_notifier_register - registers a subdevice asynchronous notifier
 227  *
 228  * @v4l2_dev: pointer to &struct v4l2_device
 229  * @notifier: pointer to &struct v4l2_async_notifier
 230  */
 231 int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
 232                                  struct v4l2_async_notifier *notifier);
 233
 234 /**
 235  * v4l2_async_subdev_notifier_register - registers a subdevice asynchronous
 236  *                                       notifier for a sub-device
 237  *
 238  * @sd: pointer to &struct v4l2_subdev
 239  * @notifier: pointer to &struct v4l2_async_notifier
 240  */
 241 int v4l2_async_subdev_notifier_register(struct v4l2_subdev *sd,
 242                                         struct v4l2_async_notifier *notifier);
 243
 244 /**
 245  * v4l2_async_notifier_unregister - unregisters a subdevice
 246  *      asynchronous notifier
 247  *
 248  * @notifier: pointer to &struct v4l2_async_notifier
 249  */
 250 void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier);
 251
 252 /**
 253  * v4l2_async_notifier_cleanup - clean up notifier resources
 254  * @notifier: the notifier the resources of which are to be cleaned up
 255  *
 256  * Release memory resources related to a notifier, including the async
 257  * sub-devices allocated for the purposes of the notifier but not the notifier
 258  * itself. The user is responsible for calling this function to clean up the
 259  * notifier after calling
 260  * @v4l2_async_notifier_add_subdev,
 261  * @v4l2_async_notifier_parse_fwnode_endpoints or
 262  * @v4l2_fwnode_reference_parse_sensor_common.
 263  *
 264  * There is no harm from calling v4l2_async_notifier_cleanup in other
 265  * cases as long as its memory has been zeroed after it has been
 266  * allocated.
 267  */
 268 void v4l2_async_notifier_cleanup(struct v4l2_async_notifier *notifier);
 269
 270 /**
 271  * v4l2_async_register_subdev - registers a sub-device to the asynchronous
 272  *      subdevice framework
 273  *
 274  * @sd: pointer to &struct v4l2_subdev
 275  */
 276 int v4l2_async_register_subdev(struct v4l2_subdev *sd);
 277
 278 /**
 279  * v4l2_async_register_subdev_sensor_common - registers a sensor sub-device to
 280  *                                            the asynchronous sub-device
 281  *                                            framework and parse set up common
 282  *                                            sensor related devices
 283  *
 284  * @sd: pointer to struct &v4l2_subdev
 285  *
 286  * This function is just like v4l2_async_register_subdev() with the exception
 287  * that calling it will also parse firmware interfaces for remote references
 288  * using v4l2_async_notifier_parse_fwnode_sensor_common() and registers the
 289  * async sub-devices. The sub-device is similarly unregistered by calling
 290  * v4l2_async_unregister_subdev().
 291  *
 292  * While registered, the subdev module is marked as in-use.
 293  *
 294  * An error is returned if the module is no longer loaded on any attempts
 295  * to register it.
 296  */
 297 int __must_check
 298 v4l2_async_register_subdev_sensor_common(struct v4l2_subdev *sd);
 299
 300 /**
 301  * v4l2_async_unregister_subdev - unregisters a sub-device to the asynchronous
 302  *      subdevice framework
 303  *
 304  * @sd: pointer to &struct v4l2_subdev
 305  */
 306 void v4l2_async_unregister_subdev(struct v4l2_subdev *sd);
 307 #endif