255 строки
7.2 KiB
C
255 строки
7.2 KiB
C
/*
|
|
* i2c-amd756-s4882.c - i2c-amd756 extras for the Tyan S4882 motherboard
|
|
*
|
|
* Copyright (C) 2004, 2008 Jean Delvare <jdelvare@suse.de>
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
/*
|
|
* We select the channels by sending commands to the Philips
|
|
* PCA9556 chip at I2C address 0x18. The main adapter is used for
|
|
* the non-multiplexed part of the bus, and 4 virtual adapters
|
|
* are defined for the multiplexed addresses: 0x50-0x53 (memory
|
|
* module EEPROM) located on channels 1-4, and 0x4c (LM63)
|
|
* located on multiplexed channels 0 and 5-7. We define one
|
|
* virtual adapter per CPU, which corresponds to two multiplexed
|
|
* channels:
|
|
* CPU0: virtual adapter 1, channels 1 and 0
|
|
* CPU1: virtual adapter 2, channels 2 and 5
|
|
* CPU2: virtual adapter 3, channels 3 and 6
|
|
* CPU3: virtual adapter 4, channels 4 and 7
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/init.h>
|
|
#include <linux/i2c.h>
|
|
#include <linux/mutex.h>
|
|
|
|
extern struct i2c_adapter amd756_smbus;
|
|
|
|
static struct i2c_adapter *s4882_adapter;
|
|
static struct i2c_algorithm *s4882_algo;
|
|
|
|
/* Wrapper access functions for multiplexed SMBus */
|
|
static DEFINE_MUTEX(amd756_lock);
|
|
|
|
static s32 amd756_access_virt0(struct i2c_adapter * adap, u16 addr,
|
|
unsigned short flags, char read_write,
|
|
u8 command, int size,
|
|
union i2c_smbus_data * data)
|
|
{
|
|
int error;
|
|
|
|
/* We exclude the multiplexed addresses */
|
|
if (addr == 0x4c || (addr & 0xfc) == 0x50 || (addr & 0xfc) == 0x30
|
|
|| addr == 0x18)
|
|
return -ENXIO;
|
|
|
|
mutex_lock(&amd756_lock);
|
|
|
|
error = amd756_smbus.algo->smbus_xfer(adap, addr, flags, read_write,
|
|
command, size, data);
|
|
|
|
mutex_unlock(&amd756_lock);
|
|
|
|
return error;
|
|
}
|
|
|
|
/* We remember the last used channels combination so as to only switch
|
|
channels when it is really needed. This greatly reduces the SMBus
|
|
overhead, but also assumes that nobody will be writing to the PCA9556
|
|
in our back. */
|
|
static u8 last_channels;
|
|
|
|
static inline s32 amd756_access_channel(struct i2c_adapter * adap, u16 addr,
|
|
unsigned short flags, char read_write,
|
|
u8 command, int size,
|
|
union i2c_smbus_data * data,
|
|
u8 channels)
|
|
{
|
|
int error;
|
|
|
|
/* We exclude the non-multiplexed addresses */
|
|
if (addr != 0x4c && (addr & 0xfc) != 0x50 && (addr & 0xfc) != 0x30)
|
|
return -ENXIO;
|
|
|
|
mutex_lock(&amd756_lock);
|
|
|
|
if (last_channels != channels) {
|
|
union i2c_smbus_data mplxdata;
|
|
mplxdata.byte = channels;
|
|
|
|
error = amd756_smbus.algo->smbus_xfer(adap, 0x18, 0,
|
|
I2C_SMBUS_WRITE, 0x01,
|
|
I2C_SMBUS_BYTE_DATA,
|
|
&mplxdata);
|
|
if (error)
|
|
goto UNLOCK;
|
|
last_channels = channels;
|
|
}
|
|
error = amd756_smbus.algo->smbus_xfer(adap, addr, flags, read_write,
|
|
command, size, data);
|
|
|
|
UNLOCK:
|
|
mutex_unlock(&amd756_lock);
|
|
return error;
|
|
}
|
|
|
|
static s32 amd756_access_virt1(struct i2c_adapter * adap, u16 addr,
|
|
unsigned short flags, char read_write,
|
|
u8 command, int size,
|
|
union i2c_smbus_data * data)
|
|
{
|
|
/* CPU0: channels 1 and 0 enabled */
|
|
return amd756_access_channel(adap, addr, flags, read_write, command,
|
|
size, data, 0x03);
|
|
}
|
|
|
|
static s32 amd756_access_virt2(struct i2c_adapter * adap, u16 addr,
|
|
unsigned short flags, char read_write,
|
|
u8 command, int size,
|
|
union i2c_smbus_data * data)
|
|
{
|
|
/* CPU1: channels 2 and 5 enabled */
|
|
return amd756_access_channel(adap, addr, flags, read_write, command,
|
|
size, data, 0x24);
|
|
}
|
|
|
|
static s32 amd756_access_virt3(struct i2c_adapter * adap, u16 addr,
|
|
unsigned short flags, char read_write,
|
|
u8 command, int size,
|
|
union i2c_smbus_data * data)
|
|
{
|
|
/* CPU2: channels 3 and 6 enabled */
|
|
return amd756_access_channel(adap, addr, flags, read_write, command,
|
|
size, data, 0x48);
|
|
}
|
|
|
|
static s32 amd756_access_virt4(struct i2c_adapter * adap, u16 addr,
|
|
unsigned short flags, char read_write,
|
|
u8 command, int size,
|
|
union i2c_smbus_data * data)
|
|
{
|
|
/* CPU3: channels 4 and 7 enabled */
|
|
return amd756_access_channel(adap, addr, flags, read_write, command,
|
|
size, data, 0x90);
|
|
}
|
|
|
|
static int __init amd756_s4882_init(void)
|
|
{
|
|
int i, error;
|
|
union i2c_smbus_data ioconfig;
|
|
|
|
if (!amd756_smbus.dev.parent)
|
|
return -ENODEV;
|
|
|
|
/* Configure the PCA9556 multiplexer */
|
|
ioconfig.byte = 0x00; /* All I/O to output mode */
|
|
error = i2c_smbus_xfer(&amd756_smbus, 0x18, 0, I2C_SMBUS_WRITE, 0x03,
|
|
I2C_SMBUS_BYTE_DATA, &ioconfig);
|
|
if (error) {
|
|
dev_err(&amd756_smbus.dev, "PCA9556 configuration failed\n");
|
|
error = -EIO;
|
|
goto ERROR0;
|
|
}
|
|
|
|
/* Unregister physical bus */
|
|
i2c_del_adapter(&amd756_smbus);
|
|
|
|
printk(KERN_INFO "Enabling SMBus multiplexing for Tyan S4882\n");
|
|
/* Define the 5 virtual adapters and algorithms structures */
|
|
if (!(s4882_adapter = kzalloc(5 * sizeof(struct i2c_adapter),
|
|
GFP_KERNEL))) {
|
|
error = -ENOMEM;
|
|
goto ERROR1;
|
|
}
|
|
if (!(s4882_algo = kzalloc(5 * sizeof(struct i2c_algorithm),
|
|
GFP_KERNEL))) {
|
|
error = -ENOMEM;
|
|
goto ERROR2;
|
|
}
|
|
|
|
/* Fill in the new structures */
|
|
s4882_algo[0] = *(amd756_smbus.algo);
|
|
s4882_algo[0].smbus_xfer = amd756_access_virt0;
|
|
s4882_adapter[0] = amd756_smbus;
|
|
s4882_adapter[0].algo = s4882_algo;
|
|
s4882_adapter[0].dev.parent = amd756_smbus.dev.parent;
|
|
for (i = 1; i < 5; i++) {
|
|
s4882_algo[i] = *(amd756_smbus.algo);
|
|
s4882_adapter[i] = amd756_smbus;
|
|
snprintf(s4882_adapter[i].name, sizeof(s4882_adapter[i].name),
|
|
"SMBus 8111 adapter (CPU%d)", i-1);
|
|
s4882_adapter[i].algo = s4882_algo+i;
|
|
s4882_adapter[i].dev.parent = amd756_smbus.dev.parent;
|
|
}
|
|
s4882_algo[1].smbus_xfer = amd756_access_virt1;
|
|
s4882_algo[2].smbus_xfer = amd756_access_virt2;
|
|
s4882_algo[3].smbus_xfer = amd756_access_virt3;
|
|
s4882_algo[4].smbus_xfer = amd756_access_virt4;
|
|
|
|
/* Register virtual adapters */
|
|
for (i = 0; i < 5; i++) {
|
|
error = i2c_add_adapter(s4882_adapter+i);
|
|
if (error) {
|
|
printk(KERN_ERR "i2c-amd756-s4882: "
|
|
"Virtual adapter %d registration "
|
|
"failed, module not inserted\n", i);
|
|
for (i--; i >= 0; i--)
|
|
i2c_del_adapter(s4882_adapter+i);
|
|
goto ERROR3;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
|
|
ERROR3:
|
|
kfree(s4882_algo);
|
|
s4882_algo = NULL;
|
|
ERROR2:
|
|
kfree(s4882_adapter);
|
|
s4882_adapter = NULL;
|
|
ERROR1:
|
|
/* Restore physical bus */
|
|
i2c_add_adapter(&amd756_smbus);
|
|
ERROR0:
|
|
return error;
|
|
}
|
|
|
|
static void __exit amd756_s4882_exit(void)
|
|
{
|
|
if (s4882_adapter) {
|
|
int i;
|
|
|
|
for (i = 0; i < 5; i++)
|
|
i2c_del_adapter(s4882_adapter+i);
|
|
kfree(s4882_adapter);
|
|
s4882_adapter = NULL;
|
|
}
|
|
kfree(s4882_algo);
|
|
s4882_algo = NULL;
|
|
|
|
/* Restore physical bus */
|
|
if (i2c_add_adapter(&amd756_smbus))
|
|
printk(KERN_ERR "i2c-amd756-s4882: "
|
|
"Physical bus restoration failed\n");
|
|
}
|
|
|
|
MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
|
|
MODULE_DESCRIPTION("S4882 SMBus multiplexing");
|
|
MODULE_LICENSE("GPL");
|
|
|
|
module_init(amd756_s4882_init);
|
|
module_exit(amd756_s4882_exit);
|