LXR linux/include/media/v4l2-i2c-drv-legacy.h

   1/*
   2 * v4l2-i2c-drv-legacy.h - contains I2C handling code that's identical
   3 *                  for all V4L2 I2C drivers. Use this header if the
   4 *                  I2C driver is used by both legacy drivers and
   5 *                  drivers converted to the bus-based I2C API.
   6 *
   7 * Copyright (C) 2007 Hans Verkuil <hverkuil@xs4all.nl>
   8 *
   9 * This program is free software; you can redistribute it and/or modify
  10 * it under the terms of the GNU General Public License as published by
  11 * the Free Software Foundation; either version 2 of the License, or
  12 * (at your option) any later version.
  13 *
  14 * This program is distributed in the hope that it will be useful,
  15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 * GNU 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., 675 Mass Ave, Cambridge, MA 02139, USA.
  22 */
  23
  24/* NOTE: the full version of this header is in the v4l-dvb repository
  25 * and allows v4l i2c drivers to be compiled on older kernels as well.
  26 * The version of this header as it appears in the kernel is a stripped
  27 * version (without all the backwards compatibility stuff) and so it
  28 * looks a bit odd.
  29 *
  30 * If you look at the full version then you will understand the reason
  31 * for introducing this header since you really don't want to have all
  32 * the tricky backwards compatibility code in each and every i2c driver.
  33 */
  34
  35struct v4l2_i2c_driver_data {
  36        const char * const name;
  37        int driverid;
  38        int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
  39        int (*probe)(struct i2c_client *client, const struct i2c_device_id *id);
  40        int (*remove)(struct i2c_client *client);
  41        int (*suspend)(struct i2c_client *client, pm_message_t state);
  42        int (*resume)(struct i2c_client *client);
  43        int (*legacy_probe)(struct i2c_adapter *adapter);
  44        int legacy_class;
  45        const struct i2c_device_id *id_table;
  46};
  47
  48static struct v4l2_i2c_driver_data v4l2_i2c_data;
  49static const struct i2c_client_address_data addr_data;
  50static struct i2c_driver v4l2_i2c_driver_legacy;
  51static char v4l2_i2c_drv_name_legacy[32];
  52
  53static int v4l2_i2c_drv_attach_legacy(struct i2c_adapter *adapter, int address, int kind)
  54{
  55        return v4l2_i2c_attach(adapter, address, &v4l2_i2c_driver_legacy,
  56                        v4l2_i2c_drv_name_legacy, v4l2_i2c_data.probe);
  57}
  58
  59static int v4l2_i2c_drv_probe_legacy(struct i2c_adapter *adapter)
  60{
  61        if (v4l2_i2c_data.legacy_probe) {
  62                if (v4l2_i2c_data.legacy_probe(adapter))
  63                        return i2c_probe(adapter, &addr_data, v4l2_i2c_drv_attach_legacy);
  64                return 0;
  65        }
  66        if (adapter->class & v4l2_i2c_data.legacy_class)
  67                return i2c_probe(adapter, &addr_data, v4l2_i2c_drv_attach_legacy);
  68        return 0;
  69}
  70
  71static int v4l2_i2c_drv_detach_legacy(struct i2c_client *client)
  72{
  73        int err;
  74
  75        if (v4l2_i2c_data.remove)
  76                v4l2_i2c_data.remove(client);
  77
  78        err = i2c_detach_client(client);
  79        if (err)
  80                return err;
  81        kfree(client);
  82        return 0;
  83}
  84
  85static int v4l2_i2c_drv_suspend_helper(struct i2c_client *client, pm_message_t state)
  86{
  87        return v4l2_i2c_data.suspend ? v4l2_i2c_data.suspend(client, state) : 0;
  88}
  89
  90static int v4l2_i2c_drv_resume_helper(struct i2c_client *client)
  91{
  92        return v4l2_i2c_data.resume ? v4l2_i2c_data.resume(client) : 0;
  93}
  94
  95/* ----------------------------------------------------------------------- */
  96
  97/* i2c implementation */
  98static struct i2c_driver v4l2_i2c_driver_legacy = {
  99        .driver = {
 100                .owner = THIS_MODULE,
 101        },
 102        .attach_adapter = v4l2_i2c_drv_probe_legacy,
 103        .detach_client = v4l2_i2c_drv_detach_legacy,
 104        .suspend = v4l2_i2c_drv_suspend_helper,
 105        .resume  = v4l2_i2c_drv_resume_helper,
 106};
 107
 108/* ----------------------------------------------------------------------- */
 109
 110/* i2c implementation */
 111static struct i2c_driver v4l2_i2c_driver = {
 112        .suspend        = v4l2_i2c_drv_suspend_helper,
 113        .resume         = v4l2_i2c_drv_resume_helper,
 114};
 115
 116static int __init v4l2_i2c_drv_init(void)
 117{
 118        int err;
 119
 120        strlcpy(v4l2_i2c_drv_name_legacy, v4l2_i2c_data.name, sizeof(v4l2_i2c_drv_name_legacy));
 121        strlcat(v4l2_i2c_drv_name_legacy, "'", sizeof(v4l2_i2c_drv_name_legacy));
 122
 123        if (v4l2_i2c_data.legacy_class == 0)
 124                v4l2_i2c_data.legacy_class = I2C_CLASS_TV_ANALOG;
 125
 126        v4l2_i2c_driver_legacy.driver.name = v4l2_i2c_drv_name_legacy;
 127        v4l2_i2c_driver_legacy.id = v4l2_i2c_data.driverid;
 128        v4l2_i2c_driver_legacy.command = v4l2_i2c_data.command;
 129        err = i2c_add_driver(&v4l2_i2c_driver_legacy);
 130
 131        if (err)
 132                return err;
 133        v4l2_i2c_driver.driver.name = v4l2_i2c_data.name;
 134        v4l2_i2c_driver.id = v4l2_i2c_data.driverid;
 135        v4l2_i2c_driver.command = v4l2_i2c_data.command;
 136        v4l2_i2c_driver.probe = v4l2_i2c_data.probe;
 137        v4l2_i2c_driver.remove = v4l2_i2c_data.remove;
 138        v4l2_i2c_driver.id_table = v4l2_i2c_data.id_table;
 139        err = i2c_add_driver(&v4l2_i2c_driver);
 140        if (err)
 141                i2c_del_driver(&v4l2_i2c_driver_legacy);
 142        return err;
 143}
 144
 145static void __exit v4l2_i2c_drv_cleanup(void)
 146{
 147        i2c_del_driver(&v4l2_i2c_driver_legacy);
 148        i2c_del_driver(&v4l2_i2c_driver);
 149}
 150
 151module_init(v4l2_i2c_drv_init);
 152module_exit(v4l2_i2c_drv_cleanup);
 153