/* 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 (0 == 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");