diff options
Diffstat (limited to 'drivers/media/video/tea6415c.c')
| -rw-r--r-- | drivers/media/video/tea6415c.c | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/drivers/media/video/tea6415c.c b/drivers/media/video/tea6415c.c new file mode 100644 index 000000000000..3ec39550bf46 --- /dev/null +++ b/drivers/media/video/tea6415c.c @@ -0,0 +1,223 @@ + /* + 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 = 0; /* 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]: ",__stringify(KBUILD_MODNAME), __FUNCTION__, __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 }; +static unsigned short normal_i2c_range[] = { 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 (0 == 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_ALGO_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 = { + .owner = THIS_MODULE, + .name = "tea6415c", + .id = I2C_DRIVERID_TEA6415C, + .flags = I2C_DF_NOTIFY, + .attach_adapter = attach, + .detach_client = detach, + .command = command, +}; + +static struct i2c_client client_template = { + I2C_DEVNAME("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"); |