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
  30 #include <linux/module.h>
  31 #include <linux/ioctl.h>
  32 #include <linux/i2c.h>
  33
  34 #include "tea6415c.h"
  35
  36 static int debug = 0;           /* insmod parameter */
  37 module_param(debug, int, 0644);
  38 MODULE_PARM_DESC(debug, "Turn on/off device debugging (default:off).");
  39 #define dprintk(args...) \
  40             do { if (debug) { printk("%s: %s()[%d]: ", KBUILD_MODNAME, __FUNCTION__, __LINE__); printk(args); } } while (0)
  41
  42 #define TEA6415C_NUM_INPUTS     8
  43 #define TEA6415C_NUM_OUTPUTS    6
  44
  45 /* addresses to scan, found only at 0x03 and/or 0x43 (7-bit) */
  46 static unsigned short normal_i2c[] = { I2C_TEA6415C_1, I2C_TEA6415C_2, 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 /* this function is called by i2c_probe */
  55 static int detect(struct i2c_adapter *adapter, int address, int kind)
  56 {
  57         struct i2c_client *client = NULL;
  58         int err = 0;
  59
  60         /* let's see whether this adapter can support what we need */
  61         if (0 == i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WRITE_BYTE)) {
  62                 return 0;
  63         }
  64
  65         /* allocate memory for client structure */
  66         client = kmalloc(sizeof(struct i2c_client), GFP_KERNEL);
  67         if (0 == client) {
  68                 return -ENOMEM;
  69         }
  70
  71         /* fill client structure */
  72         memcpy(client, &client_template, sizeof(struct i2c_client));
  73         client->addr = address;
  74         client->adapter = adapter;
  75
  76         /* tell the i2c layer a new client has arrived */
  77         if (0 != (err = i2c_attach_client(client))) {
  78                 kfree(client);
  79                 return err;
  80         }
  81
  82         printk("tea6415c: detected @ 0x%02x on adapter %s\n", address, &client->adapter->name[0]);
  83
  84         return 0;
  85 }
  86
  87 static int attach(struct i2c_adapter *adapter)
  88 {
  89         /* let's see whether this is a know adapter we can attach to */
  90         if (adapter->id != I2C_HW_SAA7146) {
  91                 dprintk("refusing to probe on unknown adapter [name='%s',id=0x%x]\n", adapter->name, adapter->id);
  92                 return -ENODEV;
  93         }
  94
  95         return i2c_probe(adapter, &addr_data, &detect);
  96 }
  97
  98 static int detach(struct i2c_client *client)
  99 {
 100         int ret = i2c_detach_client(client);
 101         kfree(client);
 102         return ret;
 103 }
 104
 105 /* makes a connection between the input-pin 'i' and the output-pin 'o'
 106    for the tea6415c-client 'client' */
 107 static int switch_matrix(struct i2c_client *client, int i, int o)
 108 {
 109         u8 byte = 0;
 110         int ret;
 111
 112         dprintk("adr:0x%02x, i:%d, o:%d\n", client->addr, i, o);
 113
 114         /* check if the pins are valid */
 115         if (0 == ((1 == i ||  3 == i ||  5 == i ||  6 == i ||  8 == i || 10 == i || 20 == i || 11 == i)
 116               && (18 == o || 17 == o || 16 == o || 15 == o || 14 == o || 13 == o)))
 117                 return -1;
 118
 119         /* to understand this, have a look at the tea6415c-specs (p.5) */
 120         switch (o) {
 121         case 18:
 122                 byte = 0x00;
 123                 break;
 124         case 14:
 125                 byte = 0x20;
 126                 break;
 127         case 16:
 128                 byte = 0x10;
 129                 break;
 130         case 17:
 131                 byte = 0x08;
 132                 break;
 133         case 15:
 134                 byte = 0x18;
 135                 break;
 136         case 13:
 137                 byte = 0x28;
 138                 break;
 139         };
 140
 141         switch (i) {
 142         case 5:
 143                 byte |= 0x00;
 144                 break;
 145         case 8:
 146                 byte |= 0x04;
 147                 break;
 148         case 3:
 149                 byte |= 0x02;
 150                 break;
 151         case 20:
 152                 byte |= 0x06;
 153                 break;
 154         case 6:
 155                 byte |= 0x01;
 156                 break;
 157         case 10:
 158                 byte |= 0x05;
 159                 break;
 160         case 1:
 161                 byte |= 0x03;
 162                 break;
 163         case 11:
 164                 byte |= 0x07;
 165                 break;
 166         };
 167
 168         ret = i2c_smbus_write_byte(client, byte);
 169         if (ret) {
 170                 dprintk("i2c_smbus_write_byte() failed, ret:%d\n", ret);
 171                 return -EIO;
 172         }
 173
 174         return ret;
 175 }
 176
 177 static int command(struct i2c_client *client, unsigned int cmd, void *arg)
 178 {
 179         struct tea6415c_multiplex *v = (struct tea6415c_multiplex *)arg;
 180         int result = 0;
 181
 182         switch (cmd) {
 183         case TEA6415C_SWITCH:
 184                 result = switch_matrix(client, v->in, v->out);
 185                 break;
 186         default:
 187                 return -ENOIOCTLCMD;
 188         }
 189
 190         return result;
 191 }
 192
 193 static struct i2c_driver driver = {
 194         .driver = {
 195                 .name = "tea6415c",
 196         },
 197         .id     = I2C_DRIVERID_TEA6415C,
 198         .attach_adapter = attach,
 199         .detach_client  = detach,
 200         .command        = command,
 201 };
 202
 203 static struct i2c_client client_template = {
 204         .name = "tea6415c",
 205         .driver = &driver,
 206 };
 207
 208 static int __init this_module_init(void)
 209 {
 210         return i2c_add_driver(&driver);
 211 }
 212
 213 static void __exit this_module_exit(void)
 214 {
 215         i2c_del_driver(&driver);
 216 }
 217
 218 module_init(this_module_init);
 219 module_exit(this_module_exit);
 220
 221 MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
 222 MODULE_DESCRIPTION("tea6415c driver");
 223 MODULE_LICENSE("GPL");