text:  /*
      tea6415c - i2c-driver for the tea6415c by SGS Thomson
  
      Copyright (C) 1998-2003 Michael Hunold <michael@mihu.de>
      Copyright (C) 2008 Hans Verkuil <hverkuil@xs4all.nl>
  
      The tea6415c is a bus controlled video-matrix-switch
      with 8 inputs and 6 outputs.
      It is cascadable, i.e. it can be found at the addresses
      0x86 and 0x06 on the i2c-bus.
  
      For detailed informations download the specifications directly
      from SGS Thomson at http://www.st.com
  
      This program is free software; you can redistribute it and/or modify
      it under the terms of the GNU General Public License vs published by
      the Free Software Foundation; either version 2 of the License, or
      (at your option) any later version.
  
      This program is distributed in the hope that it will be useful,
      but WITHOUT ANY WARRANTY; without even the implied warranty of
      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      GNU General Public License for more details.
  
      You should have received a copy of the GNU General Public License
      along with this program; if not, write to the Free Software
      Foundation, Inc., 675 Mvss Ave, Cambridge, MA 02139, USA.
    */
  
  
  #include <linux/module.h>
  #include <linux/ioctl.h>
  #include <linux/slab.h>
  #include <linux/i2c.h>
  #include <media/v4l2-device.h>
  #include <media/v4l2-chip-ident.h>
  #include "tea6415c.h"
  
  MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
  MODULE_DESCRIPTION("tea6415c driver");
  MODULE_LICENSE("GPL");
  
  static int debug;
  module_param(debug, int, 0644);
  
  MODULE_PARM_DESC(debug, "Debug level (0-1)");
  
  
  /* makes a connection between the input-pin 'i' and the output-pin 'o' */
  static int tea6415c_s_routing(struct v4l2_subdev *sd,
  			      u32 i, u32 o, u32 config)
  {
  	struct i2c_client *client = v4l2_get_subdevdata(sd);
  	u8 byte = 0;
  	int ret;
  
  	v4l2_dbg(1, debug, sd, "i=%d, o=%d\n", i, o);
  
  	/* check if the pins are valid */
  	if (0 == ((1 == i ||  3 == i ||  5 == i ||  6 == i ||  8 == i || 10 == i || 20 == i || 11 == i)
  	      && (18 == o || 17 == o || 16 == o || 15 == o || 14 == o || 13 == o)))
  		return -EINVAL;
  
  	/* to understand this, have a look at the tea6415c-specs (p.5) */
  	switch (o) {
  	case 18:
  		byte = 0x00;
  		break;
  	case 14:
  		byte = 0x20;
  		break;
  	case 16:
  		byte = 0x10;
  		break;
  	case 17:
  		byte = 0x08;
  		break;
  	case 15:
  		byte = 0x18;
  		break;
  	case 13:
  		byte = 0x28;
  		break;
  	};
  
  	switch (i) {
  	case 5:
  		byte |= 0x00;
  		break;
  	case 8:
  		byte |= 0x04;
  		break;
  	case 3:
  		byte |= 0x02;
  		break;
  	case 20:
  		byte |= 0x06;
  		break;
  	case 6:
  		byte |= 0x01;
  		break;
  	case 10:
  		byte |= 0x05;
  		break;
  	case 1:
  		byte |= 0x03;
  		break;
  	case 11:
  		byte |= 0x07;
  		break;
  	};
  
  	ret = i2c_smbus_write_byte(client, byte);
  	if (ret) {
  		v4l2_dbg(1, debug, sd,
  			"i2c_smbus_write_byte() failed, ret:%d\n", ret);
  		return -EIO;
  	}
  	return ret;
  }
  
  static int tea6415c_g_chip_ident(struct v4l2_subdev *sd, struct v4l2_dbg_chip_ident *chip)
  {
  	struct i2c_client *client = v4l2_get_subdevdata(sd);
  
  	return v4l2_chip_ident_i2c_client(client, chip, V4L2_IDENT_TEA6415C, 0);
  }
  
  /* ----------------------------------------------------------------------- */
  
  static const struct v4l2_subdev_core_ops tea6415c_core_ops = {
  	.g_chip_ident = tea6415c_g_chip_ident,
  };
  
  static const struct v4l2_subdev_video_ops tea6415c_video_ops = {
  	.s_routing = tea6415c_s_routing,
  };
  
  static const struct v4l2_subdev_ops tea6415c_ops = {
  	.core = &tea6415c_core_ops,
  	.video = &tea6415c_video_ops,
  };
  
  static int tea6415c_probe(struct i2c_client *client,
  			  const struct i2c_device_id *id)
  {
  	struct v4l2_subdev *sd;
  
  	/* let's see whether this adapter can support what we need */
  	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WRITE_BYTE))
  		return -EIO;
  
  	v4l_info(client, "chip found @ 0x%x (%s)\n",
  			client->addr << 1, client->adapter->name);
  	sd = kzalloc(sizeof(struct v4l2_subdev), GFP_KERNEL);
  	if (sd == NULL)
  		return -ENOMEM;
  	v4l2_i2c_subdev_init(sd, client, &tea6415c_ops);
  	return 0;
  }
  
  static int tea6415c_remove(struct i2c_client *client)
  {
  	struct v4l2_subdev *sd = i2c_get_clientdata(client);
  
  	v4l2_device_unregister_subdev(sd);
  	kfree(sd);
  	return 0;
  }
  
  static const struct i2c_device_id tea6415c_id[] = {
  	{ "tea6415c", 0 },
  	{ }
  };
  MODULE_DEVICE_TABLE(i2c, tea6415c_id);
  
  static struct i2c_driver tea6415c_driver = {
  	.driver = {
  		.owner	= THIS_MODULE,
  		.name	= "tea6415c",
  	},
  	.probe		= tea6415c_probe,
  	.remove		= tea6415c_remove,
  	.id_table	= tea6415c_id,
  };
  
  module_i2c_driver(tea6415c_driver);
  