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linux/drivers/i2c/busses/i2c-sis630.c

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/*
Copyright (c) 2002,2003 Alexander Malysh <amalysh@web.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.
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.
*/
/*
Status: beta
Supports:
SIS 630
SIS 730
SIS 964
Notable differences between chips:
+------------------------+--------------------+-------------------+
| | SIS630/730 | SIS964 |
+------------------------+--------------------+-------------------+
| Clock | 14kHz/56kHz | 55.56kHz/27.78kHz |
| SMBus registers offset | 0x80 | 0xE0 |
| SMB_CNT | Bit 1 = Slave Busy | Bit 1 = Bus probe |
| (not used yet) | Bit 3 is reserved | Bit 3 = Last byte |
| SMB_PCOUNT | Offset + 0x06 | Offset + 0x14 |
| SMB_COUNT | 4:0 bits | 5:0 bits |
+------------------------+--------------------+-------------------+
(Other differences don't affect the functions provided by the driver)
Note: we assume there can only be one device, with one SMBus interface.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/pci.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/i2c.h>
#include <linux/acpi.h>
#include <linux/io.h>
/* SIS964 id is defined here as we are the only file using it */
#define PCI_DEVICE_ID_SI_964 0x0964
/* SIS630/730/964 SMBus registers */
#define SMB_STS 0x00 /* status */
#define SMB_CNT 0x02 /* control */
#define SMBHOST_CNT 0x03 /* host control */
#define SMB_ADDR 0x04 /* address */
#define SMB_CMD 0x05 /* command */
#define SMB_COUNT 0x07 /* byte count */
#define SMB_BYTE 0x08 /* ~0x8F data byte field */
/* SMB_STS register */
#define BYTE_DONE_STS 0x10 /* Byte Done Status / Block Array */
#define SMBCOL_STS 0x04 /* Collision */
#define SMBERR_STS 0x02 /* Device error */
/* SMB_CNT register */
#define MSTO_EN 0x40 /* Host Master Timeout Enable */
#define SMBCLK_SEL 0x20 /* Host master clock selection */
#define SMB_PROBE 0x02 /* Bus Probe/Slave busy */
#define SMB_HOSTBUSY 0x01 /* Host Busy */
/* SMBHOST_CNT register */
#define SMB_KILL 0x20 /* Kill */
#define SMB_START 0x10 /* Start */
/* register count for request_region
* As we don't use SMB_PCOUNT, 20 is ok for SiS630 and SiS964
*/
#define SIS630_SMB_IOREGION 20
/* PCI address constants */
/* acpi base address register */
#define SIS630_ACPI_BASE_REG 0x74
/* bios control register */
#define SIS630_BIOS_CTL_REG 0x40
/* Other settings */
#define MAX_TIMEOUT 500
/* SIS630 constants */
#define SIS630_QUICK 0x00
#define SIS630_BYTE 0x01
#define SIS630_BYTE_DATA 0x02
#define SIS630_WORD_DATA 0x03
#define SIS630_PCALL 0x04
#define SIS630_BLOCK_DATA 0x05
static struct pci_driver sis630_driver;
/* insmod parameters */
static bool high_clock;
static bool force;
module_param(high_clock, bool, 0);
MODULE_PARM_DESC(high_clock,
"Set Host Master Clock to 56KHz (default 14KHz) (SIS630/730 only).");
module_param(force, bool, 0);
MODULE_PARM_DESC(force, "Forcibly enable the SIS630. DANGEROUS!");
/* SMBus base adress */
static unsigned short smbus_base;
/* supported chips */
static int supported[] = {
PCI_DEVICE_ID_SI_630,
PCI_DEVICE_ID_SI_730,
PCI_DEVICE_ID_SI_760,
0 /* terminates the list */
};
static inline u8 sis630_read(u8 reg)
{
return inb(smbus_base + reg);
}
static inline void sis630_write(u8 reg, u8 data)
{
outb(data, smbus_base + reg);
}
static int sis630_transaction_start(struct i2c_adapter *adap, int size,
u8 *oldclock)
{
int temp;
/* Make sure the SMBus host is ready to start transmitting. */
temp = sis630_read(SMB_CNT);
if ((temp & (SMB_PROBE | SMB_HOSTBUSY)) != 0x00) {
dev_dbg(&adap->dev, "SMBus busy (%02x). Resetting...\n", temp);
/* kill smbus transaction */
sis630_write(SMBHOST_CNT, SMB_KILL);
temp = sis630_read(SMB_CNT);
if (temp & (SMB_PROBE | SMB_HOSTBUSY)) {
dev_dbg(&adap->dev, "Failed! (%02x)\n", temp);
return -EBUSY;
} else {
dev_dbg(&adap->dev, "Successful!\n");
}
}
/* save old clock, so we can prevent machine for hung */
*oldclock = sis630_read(SMB_CNT);
dev_dbg(&adap->dev, "saved clock 0x%02x\n", *oldclock);
/* disable timeout interrupt,
* set Host Master Clock to 56KHz if requested */
if (high_clock)
sis630_write(SMB_CNT, SMBCLK_SEL);
else
sis630_write(SMB_CNT, (*oldclock & ~MSTO_EN));
/* clear all sticky bits */
temp = sis630_read(SMB_STS);
sis630_write(SMB_STS, temp & 0x1e);
/* start the transaction by setting bit 4 and size */
sis630_write(SMBHOST_CNT, SMB_START | (size & 0x07));
return 0;
}
static int sis630_transaction_wait(struct i2c_adapter *adap, int size)
{
int temp, result = 0, timeout = 0;
/* We will always wait for a fraction of a second! */
do {
msleep(1);
temp = sis630_read(SMB_STS);
/* check if block transmitted */
if (size == SIS630_BLOCK_DATA && (temp & BYTE_DONE_STS))
break;
} while (!(temp & 0x0e) && (timeout++ < MAX_TIMEOUT));
/* If the SMBus is still busy, we give up */
if (timeout > MAX_TIMEOUT) {
dev_dbg(&adap->dev, "SMBus Timeout!\n");
result = -ETIMEDOUT;
}
if (temp & SMBERR_STS) {
dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
result = -ENXIO;
}
if (temp & SMBCOL_STS) {
dev_err(&adap->dev, "Bus collision!\n");
result = -EAGAIN;
}
return result;
}
static void sis630_transaction_end(struct i2c_adapter *adap, u8 oldclock)
{
/* clear all status "sticky" bits */
sis630_write(SMB_STS, 0xFF);
dev_dbg(&adap->dev,
"SMB_CNT before clock restore 0x%02x\n", sis630_read(SMB_CNT));
/*
* restore old Host Master Clock if high_clock is set
* and oldclock was not 56KHz
*/
if (high_clock && !(oldclock & SMBCLK_SEL))
sis630_write(SMB_CNT, sis630_read(SMB_CNT) & ~SMBCLK_SEL);
dev_dbg(&adap->dev,
"SMB_CNT after clock restore 0x%02x\n", sis630_read(SMB_CNT));
}
static int sis630_transaction(struct i2c_adapter *adap, int size)
{
int result = 0;
u8 oldclock = 0;
result = sis630_transaction_start(adap, size, &oldclock);
if (!result) {
result = sis630_transaction_wait(adap, size);
sis630_transaction_end(adap, oldclock);
}
return result;
}
static int sis630_block_data(struct i2c_adapter *adap,
union i2c_smbus_data *data, int read_write)
{
int i, len = 0, rc = 0;
u8 oldclock = 0;
if (read_write == I2C_SMBUS_WRITE) {
len = data->block[0];
if (len < 0)
len = 0;
else if (len > 32)
len = 32;
sis630_write(SMB_COUNT, len);
for (i = 1; i <= len; i++) {
dev_dbg(&adap->dev,
"set data 0x%02x\n", data->block[i]);
/* set data */
sis630_write(SMB_BYTE + (i - 1) % 8, data->block[i]);
if (i == 8 || (len < 8 && i == len)) {
dev_dbg(&adap->dev,
"start trans len=%d i=%d\n", len, i);
/* first transaction */
rc = sis630_transaction_start(adap,
SIS630_BLOCK_DATA, &oldclock);
if (rc)
return rc;
} else if ((i - 1) % 8 == 7 || i == len) {
dev_dbg(&adap->dev,
"trans_wait len=%d i=%d\n", len, i);
if (i > 8) {
dev_dbg(&adap->dev,
"clear smbary_sts"
" len=%d i=%d\n", len, i);
/*
If this is not first transaction,
we must clear sticky bit.
clear SMBARY_STS
*/
sis630_write(SMB_STS, BYTE_DONE_STS);
}
rc = sis630_transaction_wait(adap,
SIS630_BLOCK_DATA);
if (rc) {
dev_dbg(&adap->dev,
"trans_wait failed\n");
break;
}
}
}
} else {
/* read request */
data->block[0] = len = 0;
rc = sis630_transaction_start(adap,
SIS630_BLOCK_DATA, &oldclock);
if (rc)
return rc;
do {
rc = sis630_transaction_wait(adap, SIS630_BLOCK_DATA);
if (rc) {
dev_dbg(&adap->dev, "trans_wait failed\n");
break;
}
/* if this first transaction then read byte count */
if (len == 0)
data->block[0] = sis630_read(SMB_COUNT);
/* just to be sure */
if (data->block[0] > 32)
data->block[0] = 32;
dev_dbg(&adap->dev,
"block data read len=0x%x\n", data->block[0]);
for (i = 0; i < 8 && len < data->block[0]; i++, len++) {
dev_dbg(&adap->dev,
"read i=%d len=%d\n", i, len);
data->block[len + 1] = sis630_read(SMB_BYTE +
i);
}
dev_dbg(&adap->dev,
"clear smbary_sts len=%d i=%d\n", len, i);
/* clear SMBARY_STS */
sis630_write(SMB_STS, BYTE_DONE_STS);
} while (len < data->block[0]);
}
sis630_transaction_end(adap, oldclock);
return rc;
}
/* Return negative errno on error. */
static s32 sis630_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:
sis630_write(SMB_ADDR,
((addr & 0x7f) << 1) | (read_write & 0x01));
size = SIS630_QUICK;
break;
case I2C_SMBUS_BYTE:
sis630_write(SMB_ADDR,
((addr & 0x7f) << 1) | (read_write & 0x01));
if (read_write == I2C_SMBUS_WRITE)
sis630_write(SMB_CMD, command);
size = SIS630_BYTE;
break;
case I2C_SMBUS_BYTE_DATA:
sis630_write(SMB_ADDR,
((addr & 0x7f) << 1) | (read_write & 0x01));
sis630_write(SMB_CMD, command);
if (read_write == I2C_SMBUS_WRITE)
sis630_write(SMB_BYTE, data->byte);
size = SIS630_BYTE_DATA;
break;
case I2C_SMBUS_PROC_CALL:
case I2C_SMBUS_WORD_DATA:
sis630_write(SMB_ADDR,
((addr & 0x7f) << 1) | (read_write & 0x01));
sis630_write(SMB_CMD, command);
if (read_write == I2C_SMBUS_WRITE) {
sis630_write(SMB_BYTE, data->word & 0xff);
sis630_write(SMB_BYTE + 1, (data->word & 0xff00) >> 8);
}
size = (size == I2C_SMBUS_PROC_CALL ?
SIS630_PCALL : SIS630_WORD_DATA);
break;
case I2C_SMBUS_BLOCK_DATA:
sis630_write(SMB_ADDR,
((addr & 0x7f) << 1) | (read_write & 0x01));
sis630_write(SMB_CMD, command);
size = SIS630_BLOCK_DATA;
return sis630_block_data(adap, data, read_write);
default:
dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
return -EOPNOTSUPP;
}
status = sis630_transaction(adap, size);
if (status)
return status;
if ((size != SIS630_PCALL) &&
((read_write == I2C_SMBUS_WRITE) || (size == SIS630_QUICK))) {
return 0;
}
switch (size) {
case SIS630_BYTE:
case SIS630_BYTE_DATA:
data->byte = sis630_read(SMB_BYTE);
break;
case SIS630_PCALL:
case SIS630_WORD_DATA:
data->word = sis630_read(SMB_BYTE) +
(sis630_read(SMB_BYTE + 1) << 8);
break;
}
return 0;
}
static u32 sis630_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 | I2C_FUNC_SMBUS_BLOCK_DATA;
}
static int sis630_setup(struct pci_dev *sis630_dev)
{
unsigned char b;
struct pci_dev *dummy = NULL;
int retval, i;
/* acpi base address */
unsigned short acpi_base;
/* check for supported SiS devices */
for (i = 0; supported[i] > 0; i++) {
dummy = pci_get_device(PCI_VENDOR_ID_SI, supported[i], dummy);
if (dummy)
break; /* found */
}
if (dummy) {
pci_dev_put(dummy);
} else if (force) {
dev_err(&sis630_dev->dev,
"WARNING: Can't detect SIS630 compatible device, but "
"loading because of force option enabled\n");
} else {
return -ENODEV;
}
/*
Enable ACPI first , so we can accsess reg 74-75
in acpi io space and read acpi base addr
*/
if (pci_read_config_byte(sis630_dev, SIS630_BIOS_CTL_REG, &b)) {
dev_err(&sis630_dev->dev, "Error: Can't read bios ctl reg\n");
retval = -ENODEV;
goto exit;
}
/* if ACPI already enabled , do nothing */
if (!(b & 0x80) &&
pci_write_config_byte(sis630_dev, SIS630_BIOS_CTL_REG, b | 0x80)) {
dev_err(&sis630_dev->dev, "Error: Can't enable ACPI\n");
retval = -ENODEV;
goto exit;
}
/* Determine the ACPI base address */
if (pci_read_config_word(sis630_dev,
SIS630_ACPI_BASE_REG, &acpi_base)) {
dev_err(&sis630_dev->dev,
"Error: Can't determine ACPI base address\n");
retval = -ENODEV;
goto exit;
}
dev_dbg(&sis630_dev->dev, "ACPI base at 0x%04hx\n", acpi_base);
if (supported[i] == PCI_DEVICE_ID_SI_760)
smbus_base = acpi_base + 0xE0;
else
smbus_base = acpi_base + 0x80;
dev_dbg(&sis630_dev->dev, "SMBus base at 0x%04hx\n", smbus_base);
retval = acpi_check_region(smbus_base + SMB_STS, SIS630_SMB_IOREGION,
sis630_driver.name);
if (retval)
goto exit;
/* Everything is happy, let's grab the memory and set things up. */
if (!request_region(smbus_base + SMB_STS, SIS630_SMB_IOREGION,
sis630_driver.name)) {
dev_err(&sis630_dev->dev,
"I/O Region 0x%04hx-0x%04hx for SMBus already in use.\n",
smbus_base + SMB_STS,
smbus_base + SMB_STS + SIS630_SMB_IOREGION - 1);
retval = -EBUSY;
goto exit;
}
retval = 0;
exit:
if (retval)
smbus_base = 0;
return retval;
}
static const struct i2c_algorithm smbus_algorithm = {
.smbus_xfer = sis630_access,
.functionality = sis630_func,
};
static struct i2c_adapter sis630_adapter = {
.owner = THIS_MODULE,
.class = I2C_CLASS_HWMON | I2C_CLASS_SPD,
.algo = &smbus_algorithm,
.retries = 3
};
static DEFINE_PCI_DEVICE_TABLE(sis630_ids) = {
{ PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_503) },
{ PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_LPC) },
{ PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_964) },
{ 0, }
};
MODULE_DEVICE_TABLE(pci, sis630_ids);
static int sis630_probe(struct pci_dev *dev, const struct pci_device_id *id)
{
if (sis630_setup(dev)) {
dev_err(&dev->dev,
"SIS630 compatible bus not detected, "
"module not inserted.\n");
return -ENODEV;
}
/* set up the sysfs linkage to our parent device */
sis630_adapter.dev.parent = &dev->dev;
snprintf(sis630_adapter.name, sizeof(sis630_adapter.name),
"SMBus SIS630 adapter at %04hx", smbus_base + SMB_STS);
return i2c_add_adapter(&sis630_adapter);
}
static void sis630_remove(struct pci_dev *dev)
{
if (smbus_base) {
i2c_del_adapter(&sis630_adapter);
release_region(smbus_base + SMB_STS, SIS630_SMB_IOREGION);
smbus_base = 0;
}
}
static struct pci_driver sis630_driver = {
.name = "sis630_smbus",
.id_table = sis630_ids,
.probe = sis630_probe,
.remove = sis630_remove,
};
module_pci_driver(sis630_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Alexander Malysh <amalysh@web.de>");
MODULE_DESCRIPTION("SIS630 SMBus driver");
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