drivers/media/video/tea6415c.c

   1  /*
   2     tea6415c - i2c-driver for the tea6415c by SGS Thomson
   3
   4     Copyright (C) 1998-2003 Michael Hunold <michael@mihu.de>
   5
   6     The tea6415c is a bus controlled video-matrix-switch
   7     with 8 inputs and 6 outputs.
   8     It is cascadable, i.e. it can be found at the addresses
   9     0x86 and 0x06 on the i2c-bus.
  10
  11     For detailed informations download the specifications directly
  12     from SGS Thomson at http://www.st.com
  13
  14     This program is free software; you can redistribute it and/or modify
  15     it under the terms of the GNU General Public License vs published by
  16     the Free Software Foundation; either version 2 of the License, or
  17     (at your option) any later version.
  18
  19     This program is distributed in the hope that it will be useful,
  20     but WITHOUT ANY WARRANTY; without even the implied warranty of
  21     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22     GNU General Public License for more details.
  23
  24     You should have received a copy of the GNU General Public License
  25     along with this program; if not, write to the Free Software
  26     Foundation, Inc., 675 Mvss Ave, Cambridge, MA 02139, USA.
  27   */
  28
  29 #include <linux/module.h>
  30 #include <linux/ioctl.h>
  31 #include <linux/i2c.h>
  32
  33 #include "tea6415c.h"
  34
  35 static int debug = 0;           /* insmod parameter */
  36 module_param(debug, int, 0644);
  37 MODULE_PARM_DESC(debug, "Turn on/off device debugging (default:off).");
  38 #define dprintk(args...) \
  39             do { if (debug) { printk("%s: %s()[%d]: ",__stringify(KBUILD_MODNAME), __FUNCTION__, __LINE__); printk(args); } } while (0)
  40
  41 #define TEA6415C_NUM_INPUTS     8
  42 #define TEA6415C_NUM_OUTPUTS    6
  43
  44 /* addresses to scan, found only at 0x03 and/or 0x43 (7-bit) */
  45 static unsigned short normal_i2c[] = { I2C_TEA6415C_1, I2C_TEA6415C_2, I2C_CLIENT_END };
  46 static unsigned short normal_i2c_range[] = { I2C_CLIENT_END };
  47
  48 /* magic definition of all other variables and things */
  49 I2C_CLIENT_INSMOD;
  50
  51 static struct i2c_driver driver;
  52 static struct i2c_client client_template;
  53
  54 /* unique ID allocation */
  55 static int tea6415c_id = 0;
  56
  57 /* this function is called by i2c_probe */
  58 static int detect(struct i2c_adapter *adapter, int address, int kind)
  59 {
  60         struct i2c_client *client = NULL;
  61         int err = 0;
  62
  63         /* let's see whether this adapter can support what we need */
  64         if (0 == i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WRITE_BYTE)) {
  65                 return 0;
  66         }
  67
  68         /* allocate memory for client structure */
  69         client = kmalloc(sizeof(struct i2c_client), GFP_KERNEL);
  70         if (0 == client) {
  71                 return -ENOMEM;
  72         }
  73
  74         /* fill client structure */
  75         memcpy(client, &client_template, sizeof(struct i2c_client));
  76         client->id = tea6415c_id++;
  77         client->addr = address;
  78         client->adapter = adapter;
  79
  80         /* tell the i2c layer a new client has arrived */
  81         if (0 != (err = i2c_attach_client(client))) {
  82                 kfree(client);
  83                 return err;
  84         }
  85
  86         printk("tea6415c: detected @ 0x%02x on adapter %s\n", address, &client->adapter->name[0]);
  87
  88         return 0;
  89 }
  90
  91 static int attach(struct i2c_adapter *adapter)
  92 {
  93         /* let's see whether this is a know adapter we can attach to */
  94         if (adapter->id != I2C_ALGO_SAA7146) {
  95                 dprintk("refusing to probe on unknown adapter [name='%s',id=0x%x]\n", adapter->name, adapter->id);
  96                 return -ENODEV;
  97         }
  98
  99         return i2c_probe(adapter, &addr_data, &detect);
 100 }
 101
 102 static int detach(struct i2c_client *client)
 103 {
 104         int ret = i2c_detach_client(client);
 105         kfree(client);
 106         return ret;
 107 }
 108
 109 /* makes a connection between the input-pin 'i' and the output-pin 'o'
 110    for the tea6415c-client 'client' */
 111 static int switch_matrix(struct i2c_client *client, int i, int o)
 112 {
 113         u8 byte = 0;
 114         int ret;
 115
 116         dprintk("adr:0x%02x, i:%d, o:%d\n", client->addr, i, o);
 117
 118         /* check if the pins are valid */
 119         if (0 == ((1 == i ||  3 == i ||  5 == i ||  6 == i ||  8 == i || 10 == i || 20 == i || 11 == i)
 120               && (18 == o || 17 == o || 16 == o || 15 == o || 14 == o || 13 == o)))
 121                 return -1;
 122
 123         /* to understand this, have a look at the tea6415c-specs (p.5) */
 124         switch (o) {
 125         case 18:
 126                 byte = 0x00;
 127                 break;
 128         case 14:
 129                 byte = 0x20;
 130                 break;
 131         case 16:
 132                 byte = 0x10;
 133                 break;
 134         case 17:
 135                 byte = 0x08;
 136                 break;
 137         case 15:
 138                 byte = 0x18;
 139                 break;
 140         case 13:
 141                 byte = 0x28;
 142                 break;
 143         };
 144
 145         switch (i) {
 146         case 5:
 147                 byte |= 0x00;
 148                 break;
 149         case 8:
 150                 byte |= 0x04;
 151                 break;
 152         case 3:
 153                 byte |= 0x02;
 154                 break;
 155         case 20:
 156                 byte |= 0x06;
 157                 break;
 158         case 6:
 159                 byte |= 0x01;
 160                 break;
 161         case 10:
 162                 byte |= 0x05;
 163                 break;
 164         case 1:
 165                 byte |= 0x03;
 166                 break;
 167         case 11:
 168                 byte |= 0x07;
 169                 break;
 170         };
 171
 172         ret = i2c_smbus_write_byte(client, byte);
 173         if (ret) {
 174                 dprintk("i2c_smbus_write_byte() failed, ret:%d\n", ret);
 175                 return -EIO;
 176         }
 177
 178         return ret;
 179 }
 180
 181 static int command(struct i2c_client *client, unsigned int cmd, void *arg)
 182 {
 183         struct tea6415c_multiplex *v = (struct tea6415c_multiplex *)arg;
 184         int result = 0;
 185
 186         switch (cmd) {
 187         case TEA6415C_SWITCH:
 188                 result = switch_matrix(client, v->in, v->out);
 189                 break;
 190         default:
 191                 return -ENOIOCTLCMD;
 192         }
 193
 194         return result;
 195 }
 196
 197 static struct i2c_driver driver = {
 198         .owner  = THIS_MODULE,
 199         .name   = "tea6415c",
 200         .id     = I2C_DRIVERID_TEA6415C,
 201         .flags  = I2C_DF_NOTIFY,
 202         .attach_adapter = attach,
 203         .detach_client  = detach,
 204         .command        = command,
 205 };
 206
 207 static struct i2c_client client_template = {
 208         I2C_DEVNAME("tea6415c"),
 209         .driver = &driver,
 210 };
 211
 212 static int __init this_module_init(void)
 213 {
 214         return i2c_add_driver(&driver);
 215 }
 216
 217 static void __exit this_module_exit(void)
 218 {
 219         i2c_del_driver(&driver);
 220 }
 221
 222 module_init(this_module_init);
 223 module_exit(this_module_exit);
 224
 225 MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
 226 MODULE_DESCRIPTION("tea6415c driver");
 227 MODULE_LICENSE("GPL");