From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 16 Apr 2005 15:20:36 -0700 Subject: Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! --- drivers/i2c/busses/i2c-amd756-s4882.c | 264 ++++++++++++++++++++++++++++++++++ 1 file changed, 264 insertions(+) create mode 100644 drivers/i2c/busses/i2c-amd756-s4882.c (limited to 'drivers/i2c/busses/i2c-amd756-s4882.c') diff --git a/drivers/i2c/busses/i2c-amd756-s4882.c b/drivers/i2c/busses/i2c-amd756-s4882.c new file mode 100644 index 00000000000..4e553e8c5cb --- /dev/null +++ b/drivers/i2c/busses/i2c-amd756-s4882.c @@ -0,0 +1,264 @@ +/* + * i2c-amd756-s4882.c - i2c-amd756 extras for the Tyan S4882 motherboard + * + * Copyright (C) 2004 Jean Delvare + * + * 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. + */ + +/* + * 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 +#include +#include +#include +#include + +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 struct semaphore 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 -1; + + down(&amd756_lock); + + error = amd756_smbus.algo->smbus_xfer(adap, addr, flags, read_write, + command, size, data); + + up(&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 -1; + + down(&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: + up(&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; + + /* Unregister physical bus */ + error = i2c_del_adapter(&amd756_smbus); + if (error) { + if (error == -EINVAL) + error = -ENODEV; + else + dev_err(&amd756_smbus.dev, "Physical bus removal " + "failed\n"); + goto ERROR0; + } + + printk(KERN_INFO "Enabling SMBus multiplexing for Tyan S4882\n"); + init_MUTEX(&amd756_lock); + + /* Define the 5 virtual adapters and algorithms structures */ + if (!(s4882_adapter = kmalloc(5 * sizeof(struct i2c_adapter), + GFP_KERNEL))) { + error = -ENOMEM; + goto ERROR1; + } + if (!(s4882_algo = kmalloc(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; + for (i = 1; i < 5; i++) { + s4882_algo[i] = *(amd756_smbus.algo); + s4882_adapter[i] = amd756_smbus; + sprintf(s4882_adapter[i].name, + "SMBus 8111 adapter (CPU%d)", i-1); + s4882_adapter[i].algo = s4882_algo+i; + } + 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; + + /* Configure the PCA9556 multiplexer */ + ioconfig.byte = 0x00; /* All I/O to output mode */ + error = amd756_smbus.algo->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 ERROR3; + } + + /* Register virtual adapters */ + for (i = 0; i < 5; i++) { + error = i2c_add_adapter(s4882_adapter+i); + if (error) { + dev_err(&amd756_smbus.dev, + "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: + i2c_del_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; + } + if (s4882_algo) { + kfree(s4882_algo); + s4882_algo = NULL; + } + + /* Restore physical bus */ + if (i2c_add_adapter(&amd756_smbus)) + dev_err(&amd756_smbus.dev, "Physical bus restoration " + "failed\n"); +} + +MODULE_AUTHOR("Jean Delvare "); +MODULE_DESCRIPTION("S4882 SMBus multiplexing"); +MODULE_LICENSE("GPL"); + +module_init(amd756_s4882_init); +module_exit(amd756_s4882_exit); -- cgit v1.2.3