|  | /* | 
|  | 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_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"); |