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linux/drivers/i2c/busses/i2c-sis96x.c
Jean Delvare 18669eabde i2c: Hide probe errors caused by ACPI resource conflicts 
When an ACPI resource conflict is detected, error messages are already
printed by ACPI. There's no point in causing the driver core to print
more error messages, so return one of the error codes for which no
message is printed.

This fixes bug #14293:
http://bugzilla.kernel.org/show_bug.cgi?id=14293

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-10-04 22:53:45 +02:00

345 lines
8.8 KiB
C
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/*
Copyright (c) 2003 Mark M. Hoffman <mhoffman@lightlink.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.
*/
/*
This module must be considered BETA unless and until
the chipset manufacturer releases a datasheet.
The register definitions are based on the SiS630.
This module relies on quirk_sis_96x_smbus (drivers/pci/quirks.c)
for just about every machine for which users have reported.
If this module isn't detecting your 96x south bridge, have a
look there.
We assume there can only be one SiS96x with one SMBus interface.
*/
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/stddef.h>
#include <linux/ioport.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/acpi.h>
#include <asm/io.h>
/* base address register in PCI config space */
#define SIS96x_BAR 0x04
/* SiS96x SMBus registers */
#define SMB_STS 0x00
#define SMB_EN 0x01
#define SMB_CNT 0x02
#define SMB_HOST_CNT 0x03
#define SMB_ADDR 0x04
#define SMB_CMD 0x05
#define SMB_PCOUNT 0x06
#define SMB_COUNT 0x07
#define SMB_BYTE 0x08
#define SMB_DEV_ADDR 0x10
#define SMB_DB0 0x11
#define SMB_DB1 0x12
#define SMB_SAA 0x13
/* register count for request_region */
#define SMB_IOSIZE 0x20
/* Other settings */
#define MAX_TIMEOUT 500
/* SiS96x SMBus constants */
#define SIS96x_QUICK 0x00
#define SIS96x_BYTE 0x01
#define SIS96x_BYTE_DATA 0x02
#define SIS96x_WORD_DATA 0x03
#define SIS96x_PROC_CALL 0x04
#define SIS96x_BLOCK_DATA 0x05
static struct pci_driver sis96x_driver;
static struct i2c_adapter sis96x_adapter;
static u16 sis96x_smbus_base;
static inline u8 sis96x_read(u8 reg)
{
return inb(sis96x_smbus_base + reg) ;
}
static inline void sis96x_write(u8 reg, u8 data)
{
outb(data, sis96x_smbus_base + reg) ;
}
/* Execute a SMBus transaction.
int size is from SIS96x_QUICK to SIS96x_BLOCK_DATA
*/
static int sis96x_transaction(int size)
{
int temp;
int result = 0;
int timeout = 0;
dev_dbg(&sis96x_adapter.dev, "SMBus transaction %d\n", size);
/* Make sure the SMBus host is ready to start transmitting */
if (((temp = sis96x_read(SMB_CNT)) & 0x03) != 0x00) {
dev_dbg(&sis96x_adapter.dev, "SMBus busy (0x%02x). "
"Resetting...\n", temp);
/* kill the transaction */
sis96x_write(SMB_HOST_CNT, 0x20);
/* check it again */
if (((temp = sis96x_read(SMB_CNT)) & 0x03) != 0x00) {
dev_dbg(&sis96x_adapter.dev, "Failed (0x%02x)\n", temp);
return -EBUSY;
} else {
dev_dbg(&sis96x_adapter.dev, "Successful\n");
}
}
/* Turn off timeout interrupts, set fast host clock */
sis96x_write(SMB_CNT, 0x20);
/* clear all (sticky) status flags */
temp = sis96x_read(SMB_STS);
sis96x_write(SMB_STS, temp & 0x1e);
/* start the transaction by setting bit 4 and size bits */
sis96x_write(SMB_HOST_CNT, 0x10 | (size & 0x07));
/* We will always wait for a fraction of a second! */
do {
msleep(1);
temp = sis96x_read(SMB_STS);
} while (!(temp & 0x0e) && (timeout++ < MAX_TIMEOUT));
/* If the SMBus is still busy, we give up */
if (timeout > MAX_TIMEOUT) {
dev_dbg(&sis96x_adapter.dev, "SMBus Timeout! (0x%02x)\n", temp);
result = -ETIMEDOUT;
}
/* device error - probably missing ACK */
if (temp & 0x02) {
dev_dbg(&sis96x_adapter.dev, "Failed bus transaction!\n");
result = -ENXIO;
}
/* bus collision */
if (temp & 0x04) {
dev_dbg(&sis96x_adapter.dev, "Bus collision!\n");
result = -EIO;
}
/* Finish up by resetting the bus */
sis96x_write(SMB_STS, temp);
if ((temp = sis96x_read(SMB_STS))) {
dev_dbg(&sis96x_adapter.dev, "Failed reset at "
"end of transaction! (0x%02x)\n", temp);
}
return result;
}
/* Return negative errno on error. */
static s32 sis96x_access(struct i2c_adapter * adap, u16 addr,
unsigned short flags, char read_write,
u8 command, int size, union i2c_smbus_data * data)
{
int status;
switch (size) {
case I2C_SMBUS_QUICK:
sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
size = SIS96x_QUICK;
break;
case I2C_SMBUS_BYTE:
sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
if (read_write == I2C_SMBUS_WRITE)
sis96x_write(SMB_CMD, command);
size = SIS96x_BYTE;
break;
case I2C_SMBUS_BYTE_DATA:
sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
sis96x_write(SMB_CMD, command);
if (read_write == I2C_SMBUS_WRITE)
sis96x_write(SMB_BYTE, data->byte);
size = SIS96x_BYTE_DATA;
break;
case I2C_SMBUS_PROC_CALL:
case I2C_SMBUS_WORD_DATA:
sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
sis96x_write(SMB_CMD, command);
if (read_write == I2C_SMBUS_WRITE) {
sis96x_write(SMB_BYTE, data->word & 0xff);
sis96x_write(SMB_BYTE + 1, (data->word & 0xff00) >> 8);
}
size = (size == I2C_SMBUS_PROC_CALL ?
SIS96x_PROC_CALL : SIS96x_WORD_DATA);
break;
default:
dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
return -EOPNOTSUPP;
}
status = sis96x_transaction(size);
if (status)
return status;
if ((size != SIS96x_PROC_CALL) &&
((read_write == I2C_SMBUS_WRITE) || (size == SIS96x_QUICK)))
return 0;
switch (size) {
case SIS96x_BYTE:
case SIS96x_BYTE_DATA:
data->byte = sis96x_read(SMB_BYTE);
break;
case SIS96x_WORD_DATA:
case SIS96x_PROC_CALL:
data->word = sis96x_read(SMB_BYTE) +
(sis96x_read(SMB_BYTE + 1) << 8);
break;
}
return 0;
}
static u32 sis96x_func(struct i2c_adapter *adapter)
{
return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
I2C_FUNC_SMBUS_PROC_CALL;
}
static const struct i2c_algorithm smbus_algorithm = {
.smbus_xfer = sis96x_access,
.functionality = sis96x_func,
};
static struct i2c_adapter sis96x_adapter = {
.owner = THIS_MODULE,
.class = I2C_CLASS_HWMON | I2C_CLASS_SPD,
.algo = &smbus_algorithm,
};
static struct pci_device_id sis96x_ids[] = {
{ PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_SMBUS) },
{ 0, }
};
MODULE_DEVICE_TABLE (pci, sis96x_ids);
static int __devinit sis96x_probe(struct pci_dev *dev,
const struct pci_device_id *id)
{
u16 ww = 0;
int retval;
if (sis96x_smbus_base) {
dev_err(&dev->dev, "Only one device supported.\n");
return -EBUSY;
}
pci_read_config_word(dev, PCI_CLASS_DEVICE, &ww);
if (PCI_CLASS_SERIAL_SMBUS != ww) {
dev_err(&dev->dev, "Unsupported device class 0x%04x!\n", ww);
return -ENODEV;
}
sis96x_smbus_base = pci_resource_start(dev, SIS96x_BAR);
if (!sis96x_smbus_base) {
dev_err(&dev->dev, "SiS96x SMBus base address "
"not initialized!\n");
return -EINVAL;
}
dev_info(&dev->dev, "SiS96x SMBus base address: 0x%04x\n",
sis96x_smbus_base);
retval = acpi_check_resource_conflict(&dev->resource[SIS96x_BAR]);
if (retval)
return -ENODEV;
/* Everything is happy, let's grab the memory and set things up. */
if (!request_region(sis96x_smbus_base, SMB_IOSIZE,
sis96x_driver.name)) {
dev_err(&dev->dev, "SMBus registers 0x%04x-0x%04x "
"already in use!\n", sis96x_smbus_base,
sis96x_smbus_base + SMB_IOSIZE - 1);
sis96x_smbus_base = 0;
return -EINVAL;
}
/* set up the sysfs linkage to our parent device */
sis96x_adapter.dev.parent = &dev->dev;
snprintf(sis96x_adapter.name, sizeof(sis96x_adapter.name),
"SiS96x SMBus adapter at 0x%04x", sis96x_smbus_base);
if ((retval = i2c_add_adapter(&sis96x_adapter))) {
dev_err(&dev->dev, "Couldn't register adapter!\n");
release_region(sis96x_smbus_base, SMB_IOSIZE);
sis96x_smbus_base = 0;
}
return retval;
}
static void __devexit sis96x_remove(struct pci_dev *dev)
{
if (sis96x_smbus_base) {
i2c_del_adapter(&sis96x_adapter);
release_region(sis96x_smbus_base, SMB_IOSIZE);
sis96x_smbus_base = 0;
}
}
static struct pci_driver sis96x_driver = {
.name = "sis96x_smbus",
.id_table = sis96x_ids,
.probe = sis96x_probe,
.remove = __devexit_p(sis96x_remove),
};
static int __init i2c_sis96x_init(void)
{
return pci_register_driver(&sis96x_driver);
}
static void __exit i2c_sis96x_exit(void)
{
pci_unregister_driver(&sis96x_driver);
}
MODULE_AUTHOR("Mark M. Hoffman <mhoffman@lightlink.com>");
MODULE_DESCRIPTION("SiS96x SMBus driver");
MODULE_LICENSE("GPL");
/* Register initialization functions using helper macros */
module_init(i2c_sis96x_init);
module_exit(i2c_sis96x_exit);
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