| /* |
| tda9840 - i2c-driver for the tda9840 by SGS Thomson |
| |
| Copyright (C) 1998-2003 Michael Hunold <michael@mihu.de> |
| |
| The tda9840 is a stereo/dual sound processor with digital |
| identification. It can be found at address 0x84 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 "tda9840.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]: ", KBUILD_MODNAME, __FUNCTION__, __LINE__); printk(args); } } while (0) |
| |
| #define SWITCH 0x00 |
| #define LEVEL_ADJUST 0x02 |
| #define STEREO_ADJUST 0x03 |
| #define TEST 0x04 |
| |
| /* addresses to scan, found only at 0x42 (7-Bit) */ |
| static unsigned short normal_i2c[] = { I2C_ADDR_TDA9840, 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; |
| |
| static int command(struct i2c_client *client, unsigned int cmd, void *arg) |
| { |
| int result; |
| int byte = *(int *)arg; |
| |
| switch (cmd) { |
| case TDA9840_SWITCH: |
| |
| dprintk("TDA9840_SWITCH: 0x%02x\n", byte); |
| |
| if (byte != TDA9840_SET_MONO |
| && byte != TDA9840_SET_MUTE |
| && byte != TDA9840_SET_STEREO |
| && byte != TDA9840_SET_LANG1 |
| && byte != TDA9840_SET_LANG2 |
| && byte != TDA9840_SET_BOTH |
| && byte != TDA9840_SET_BOTH_R |
| && byte != TDA9840_SET_EXTERNAL) { |
| return -EINVAL; |
| } |
| |
| result = i2c_smbus_write_byte_data(client, SWITCH, byte); |
| if (result) |
| dprintk("i2c_smbus_write_byte() failed, ret:%d\n", result); |
| break; |
| |
| case TDA9840_LEVEL_ADJUST: |
| |
| dprintk("TDA9840_LEVEL_ADJUST: %d\n", byte); |
| |
| /* check for correct range */ |
| if (byte > 25 || byte < -20) |
| return -EINVAL; |
| |
| /* calculate actual value to set, see specs, page 18 */ |
| byte /= 5; |
| if (0 < byte) |
| byte += 0x8; |
| else |
| byte = -byte; |
| |
| result = i2c_smbus_write_byte_data(client, LEVEL_ADJUST, byte); |
| if (result) |
| dprintk("i2c_smbus_write_byte() failed, ret:%d\n", result); |
| break; |
| |
| case TDA9840_STEREO_ADJUST: |
| |
| dprintk("TDA9840_STEREO_ADJUST: %d\n", byte); |
| |
| /* check for correct range */ |
| if (byte > 25 || byte < -24) |
| return -EINVAL; |
| |
| /* calculate actual value to set */ |
| byte /= 5; |
| if (0 < byte) |
| byte += 0x20; |
| else |
| byte = -byte; |
| |
| result = i2c_smbus_write_byte_data(client, STEREO_ADJUST, byte); |
| if (result) |
| dprintk("i2c_smbus_write_byte() failed, ret:%d\n", result); |
| break; |
| |
| case TDA9840_DETECT: { |
| int *ret = (int *)arg; |
| |
| byte = i2c_smbus_read_byte_data(client, STEREO_ADJUST); |
| if (byte == -1) { |
| dprintk("i2c_smbus_read_byte_data() failed\n"); |
| return -EIO; |
| } |
| |
| if (0 != (byte & 0x80)) { |
| dprintk("TDA9840_DETECT: register contents invalid\n"); |
| return -EINVAL; |
| } |
| |
| dprintk("TDA9840_DETECT: byte: 0x%02x\n", byte); |
| *ret = ((byte & 0x60) >> 5); |
| result = 0; |
| break; |
| } |
| case TDA9840_TEST: |
| dprintk("TDA9840_TEST: 0x%02x\n", byte); |
| |
| /* mask out irrelevant bits */ |
| byte &= 0x3; |
| |
| result = i2c_smbus_write_byte_data(client, TEST, byte); |
| if (result) |
| dprintk("i2c_smbus_write_byte() failed, ret:%d\n", result); |
| break; |
| default: |
| return -ENOIOCTLCMD; |
| } |
| |
| if (result) |
| return -EIO; |
| |
| return 0; |
| } |
| |
| static int detect(struct i2c_adapter *adapter, int address, int kind) |
| { |
| struct i2c_client *client; |
| int result = 0; |
| |
| int byte = 0x0; |
| |
| /* let's see whether this adapter can support what we need */ |
| if (0 == i2c_check_functionality(adapter, |
| I2C_FUNC_SMBUS_READ_BYTE_DATA | |
| I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) { |
| return 0; |
| } |
| |
| /* allocate memory for client structure */ |
| client = kmalloc(sizeof(struct i2c_client), GFP_KERNEL); |
| if (!client) { |
| printk("not enough kernel memory\n"); |
| 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 != (result = i2c_attach_client(client))) { |
| kfree(client); |
| return result; |
| } |
| |
| /* set initial values for level & stereo - adjustment, mode */ |
| byte = 0; |
| result = command(client, TDA9840_LEVEL_ADJUST, &byte); |
| result += command(client, TDA9840_STEREO_ADJUST, &byte); |
| byte = TDA9840_SET_MONO; |
| result = command(client, TDA9840_SWITCH, &byte); |
| if (result) { |
| dprintk("could not initialize tda9840\n"); |
| return -ENODEV; |
| } |
| |
| printk("tda9840: 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; |
| } |
| |
| static struct i2c_driver driver = { |
| .driver = { |
| .name = "tda9840", |
| }, |
| .id = I2C_DRIVERID_TDA9840, |
| .attach_adapter = attach, |
| .detach_client = detach, |
| .command = command, |
| }; |
| |
| static struct i2c_client client_template = { |
| .name = "tda9840", |
| .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("tda9840 driver"); |
| MODULE_LICENSE("GPL"); |