diff options
Diffstat (limited to 'drivers/media/video/tea6420.c')
| -rw-r--r-- | drivers/media/video/tea6420.c | 200 |
1 files changed, 200 insertions, 0 deletions
diff --git a/drivers/media/video/tea6420.c b/drivers/media/video/tea6420.c new file mode 100644 index 0000000..bd10710 --- /dev/null +++ b/drivers/media/video/tea6420.c @@ -0,0 +1,200 @@ + /* + tea6420 - i2c-driver for the tea6420 by SGS Thomson + + Copyright (C) 1998-2003 Michael Hunold <michael@mihu.de> + + The tea6420 is a bus controlled audio-matrix with 5 stereo inputs, + 4 stereo outputs and gain control for each output. + It is cascadable, i.e. it can be found at the adresses 0x98 + and 0x9a 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 as 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 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include <linux/module.h> +#include <linux/ioctl.h> +#include <linux/i2c.h> + +#include "tea6420.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) + +/* addresses to scan, found only at 0x4c and/or 0x4d (7-Bit) */ +static unsigned short normal_i2c[] = { I2C_TEA6420_1, I2C_TEA6420_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; + +/* make a connection between the input 'i' and the output 'o' + with gain 'g' for the tea6420-client 'client' (note: i = 6 means 'mute') */ +static int tea6420_switch(struct i2c_client *client, int i, int o, int g) +{ + u8 byte = 0; + int ret; + + dprintk("adr:0x%02x, i:%d, o:%d, g:%d\n", client->addr, i, o, g); + + /* check if the paramters are valid */ + if (i < 1 || i > 6 || o < 1 || o > 4 || g < 0 || g > 6 || g % 2 != 0) + return -1; + + byte = ((o - 1) << 5); + byte |= (i - 1); + + /* to understand this, have a look at the tea6420-specs (p.5) */ + switch (g) { + case 0: + byte |= (3 << 3); + break; + case 2: + byte |= (2 << 3); + break; + case 4: + byte |= (1 << 3); + break; + case 6: + break; + } + + ret = i2c_smbus_write_byte(client, byte); + if (ret) { + dprintk("i2c_smbus_write_byte() failed, ret:%d\n", ret); + return -EIO; + } + + return 0; +} + +/* this function is called by i2c_probe */ +static int tea6420_detect(struct i2c_adapter *adapter, int address, int kind) +{ + struct i2c_client *client; + int err = 0, i = 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; + } + memset(client, 0x0, sizeof(struct i2c_client)); + + /* 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; + } + + /* set initial values: set "mute"-input to all outputs at gain 0 */ + err = 0; + for (i = 1; i < 5; i++) { + err += tea6420_switch(client, 6, i, 0); + } + if (err) { + dprintk("could not initialize tea6420\n"); + kfree(client); + return -ENODEV; + } + + printk("tea6420: 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, &tea6420_detect); +} + +static int detach(struct i2c_client *client) +{ + int ret = i2c_detach_client(client); + kfree(client); + return ret; +} + +static int command(struct i2c_client *client, unsigned int cmd, void *arg) +{ + struct tea6420_multiplex *a = (struct tea6420_multiplex *)arg; + int result = 0; + + switch (cmd) { + case TEA6420_SWITCH: + result = tea6420_switch(client, a->in, a->out, a->gain); + break; + default: + return -ENOIOCTLCMD; + } + + return result; +} + +static struct i2c_driver driver = { + .owner = THIS_MODULE, + .name = "tea6420", + .id = I2C_DRIVERID_TEA6420, + .flags = I2C_DF_NOTIFY, + .attach_adapter = attach, + .detach_client = detach, + .command = command, +}; + +static struct i2c_client client_template = { + I2C_DEVNAME("tea6420"), + .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("tea6420 driver"); +MODULE_LICENSE("GPL"); |
