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 36static int debug = 0; /* insmod parameter */ 37module_param(debug, int, 0644); 38MODULE_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) */ 46static unsigned short normal_i2c[] = { I2C_TEA6415C_1, I2C_TEA6415C_2, I2C_CLIENT_END }; 47 48/* magic definition of all other variables and things */ 49I2C_CLIENT_INSMOD; 50 51static struct i2c_driver driver; 52static struct i2c_client client_template; 53 54/* this function is called by i2c_probe */ 55static 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 87static 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 98static 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' */ 107static 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 177static 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 193static 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 203static struct i2c_client client_template = { 204 .name = "tea6415c", 205 .driver = &driver, 206}; 207 208static int __init this_module_init(void) 209{ 210 return i2c_add_driver(&driver); 211} 212 213static void __exit this_module_exit(void) 214{ 215 i2c_del_driver(&driver); 216} 217 218module_init(this_module_init); 219module_exit(this_module_exit); 220 221MODULE_AUTHOR("Michael Hunold <michael@mihu.de>"); 222MODULE_DESCRIPTION("tea6415c driver"); 223MODULE_LICENSE("GPL"); 224