/* tea6415c - i2c-driver for the tea6415c by SGS Thomson Copyright (C) 1998-2003 Michael Hunold <michael@mihu.de> 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/i2c.h> #include "tea6415c.h" static int debug; /* insmod parameter */ module_param(debug, int, 0644); MODULE_PARM_DESC(debug, "Turn on/off device debugging (default:off)."); #define dprintk(args...) \ do { if (debug) { printk("%s: %s()[%d]: ", KBUILD_MODNAME, __func__, __LINE__); printk(args); } } while (0) #define TEA6415C_NUM_INPUTS 8 #define TEA6415C_NUM_OUTPUTS 6 /* addresses to scan, found only at 0x03 and/or 0x43 (7-bit) */ static unsigned short normal_i2c[] = { I2C_TEA6415C_1, I2C_TEA6415C_2, I2C_CLIENT_END }; /* magic definition of all other variables and things */ I2C_CLIENT_INSMOD; static struct i2c_driver driver; static struct i2c_client client_template; /* this function is called by i2c_probe */ static int detect(struct i2c_adapter *adapter, int address, int kind) { struct i2c_client *client = NULL; int err = 0; /* let's see whether this adapter can support what we need */ if (0 == i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WRITE_BYTE)) { return 0; } /* allocate memory for client structure */ client = kmalloc(sizeof(struct i2c_client), GFP_KERNEL); if (!client) { return -ENOMEM; } /* fill client structure */ memcpy(client, &client_template, sizeof(struct i2c_client)); client->addr = address; client->adapter = adapter; /* tell the i2c layer a new client has arrived */ if (0 != (err = i2c_attach_client(client))) { kfree(client); return err; } printk("tea6415c: detected @ 0x%02x on adapter %s\n", address, &client->adapter->name[0]); return 0; } static int attach(struct i2c_adapter *adapter) { /* let's see whether this is a know adapter we can attach to */ if (adapter->id != I2C_HW_SAA7146) { dprintk("refusing to probe on unknown adapter [name='%s',id=0x%x]\n", adapter->name, adapter->id); return -ENODEV; } return i2c_probe(adapter, &addr_data, &detect); } static int detach(struct i2c_client *client) { int ret = i2c_detach_client(client); kfree(client); return ret; } /* makes a connection between the input-pin 'i' and the output-pin 'o' for the tea6415c-client 'client' */ static int switch_matrix(struct i2c_client *client, int i, int o) { u8 byte = 0; int ret; dprintk("adr:0x%02x, i:%d, o:%d\n", client->addr, 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 -1; /* 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) { dprintk("i2c_smbus_write_byte() failed, ret:%d\n", ret); return -EIO; } return ret; } static int command(struct i2c_client *client, unsigned int cmd, void *arg) { struct tea6415c_multiplex *v = (struct tea6415c_multiplex *)arg; int result = 0; switch (cmd) { case TEA6415C_SWITCH: result = switch_matrix(client, v->in, v->out); break; default: return -ENOIOCTLCMD; } return result; } static struct i2c_driver driver = { .driver = { .name = "tea6415c", }, .id = I2C_DRIVERID_TEA6415C, .attach_adapter = attach, .detach_client = detach, .command = command, }; static struct i2c_client client_template = { .name = "tea6415c", .driver = &driver, }; static int __init this_module_init(void) { return i2c_add_driver(&driver); } static void __exit this_module_exit(void) { i2c_del_driver(&driver); } module_init(this_module_init); module_exit(this_module_exit); MODULE_AUTHOR("Michael Hunold <michael@mihu.de>"); MODULE_DESCRIPTION("tea6415c driver"); MODULE_LICENSE("GPL");