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222 lines
5.2 KiB
C
222 lines
5.2 KiB
C
/*
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tea6415c - i2c-driver for the tea6415c by SGS Thomson
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Copyright (C) 1998-2003 Michael Hunold <michael@mihu.de>
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The tea6415c is a bus controlled video-matrix-switch
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with 8 inputs and 6 outputs.
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It is cascadable, i.e. it can be found at the addresses
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0x86 and 0x06 on the i2c-bus.
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For detailed informations download the specifications directly
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from SGS Thomson at http://www.st.com
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License vs published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mvss Ave, Cambridge, MA 02139, USA.
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*/
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#include <linux/module.h>
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#include <linux/ioctl.h>
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#include <linux/i2c.h>
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#include "tea6415c.h"
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static int debug = 0; /* insmod parameter */
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module_param(debug, int, 0644);
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MODULE_PARM_DESC(debug, "Turn on/off device debugging (default:off).");
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#define dprintk(args...) \
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do { if (debug) { printk("%s: %s()[%d]: ", KBUILD_MODNAME, __FUNCTION__, __LINE__); printk(args); } } while (0)
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#define TEA6415C_NUM_INPUTS 8
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#define TEA6415C_NUM_OUTPUTS 6
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/* addresses to scan, found only at 0x03 and/or 0x43 (7-bit) */
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static unsigned short normal_i2c[] = { I2C_TEA6415C_1, I2C_TEA6415C_2, I2C_CLIENT_END };
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/* magic definition of all other variables and things */
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I2C_CLIENT_INSMOD;
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static struct i2c_driver driver;
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static struct i2c_client client_template;
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/* this function is called by i2c_probe */
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static int detect(struct i2c_adapter *adapter, int address, int kind)
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{
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struct i2c_client *client = NULL;
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int err = 0;
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/* let's see whether this adapter can support what we need */
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if (0 == i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WRITE_BYTE)) {
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return 0;
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}
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/* allocate memory for client structure */
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client = kmalloc(sizeof(struct i2c_client), GFP_KERNEL);
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if (0 == client) {
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return -ENOMEM;
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}
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/* fill client structure */
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memcpy(client, &client_template, sizeof(struct i2c_client));
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client->addr = address;
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client->adapter = adapter;
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/* tell the i2c layer a new client has arrived */
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if (0 != (err = i2c_attach_client(client))) {
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kfree(client);
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return err;
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}
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printk("tea6415c: detected @ 0x%02x on adapter %s\n", address, &client->adapter->name[0]);
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return 0;
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}
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static int attach(struct i2c_adapter *adapter)
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{
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/* let's see whether this is a know adapter we can attach to */
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if (adapter->id != I2C_HW_SAA7146) {
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dprintk("refusing to probe on unknown adapter [name='%s',id=0x%x]\n", adapter->name, adapter->id);
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return -ENODEV;
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}
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return i2c_probe(adapter, &addr_data, &detect);
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}
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static int detach(struct i2c_client *client)
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{
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int ret = i2c_detach_client(client);
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kfree(client);
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return ret;
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}
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/* makes a connection between the input-pin 'i' and the output-pin 'o'
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for the tea6415c-client 'client' */
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static int switch_matrix(struct i2c_client *client, int i, int o)
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{
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u8 byte = 0;
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int ret;
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dprintk("adr:0x%02x, i:%d, o:%d\n", client->addr, i, o);
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/* check if the pins are valid */
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if (0 == ((1 == i || 3 == i || 5 == i || 6 == i || 8 == i || 10 == i || 20 == i || 11 == i)
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&& (18 == o || 17 == o || 16 == o || 15 == o || 14 == o || 13 == o)))
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return -1;
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/* to understand this, have a look at the tea6415c-specs (p.5) */
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switch (o) {
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case 18:
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byte = 0x00;
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break;
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case 14:
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byte = 0x20;
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break;
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case 16:
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byte = 0x10;
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break;
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case 17:
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byte = 0x08;
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break;
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case 15:
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byte = 0x18;
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break;
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case 13:
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byte = 0x28;
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break;
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};
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switch (i) {
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case 5:
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byte |= 0x00;
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break;
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case 8:
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byte |= 0x04;
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break;
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case 3:
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byte |= 0x02;
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break;
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case 20:
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byte |= 0x06;
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break;
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case 6:
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byte |= 0x01;
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break;
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case 10:
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byte |= 0x05;
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break;
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case 1:
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byte |= 0x03;
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break;
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case 11:
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byte |= 0x07;
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break;
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};
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ret = i2c_smbus_write_byte(client, byte);
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if (ret) {
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dprintk("i2c_smbus_write_byte() failed, ret:%d\n", ret);
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return -EIO;
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}
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return ret;
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}
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static int command(struct i2c_client *client, unsigned int cmd, void *arg)
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{
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struct tea6415c_multiplex *v = (struct tea6415c_multiplex *)arg;
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int result = 0;
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switch (cmd) {
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case TEA6415C_SWITCH:
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result = switch_matrix(client, v->in, v->out);
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break;
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default:
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return -ENOIOCTLCMD;
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}
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return result;
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}
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static struct i2c_driver driver = {
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.driver = {
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.name = "tea6415c",
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},
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.id = I2C_DRIVERID_TEA6415C,
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.attach_adapter = attach,
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.detach_client = detach,
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.command = command,
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};
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static struct i2c_client client_template = {
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.name = "tea6415c",
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.driver = &driver,
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};
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static int __init this_module_init(void)
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{
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return i2c_add_driver(&driver);
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}
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static void __exit this_module_exit(void)
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{
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i2c_del_driver(&driver);
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}
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module_init(this_module_init);
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module_exit(this_module_exit);
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MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
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MODULE_DESCRIPTION("tea6415c driver");
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MODULE_LICENSE("GPL");
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