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linux/drivers/i2c/busses/i2c-pasemi.c
Jean Delvare 3401b2fff3 i2c: Let bus drivers add SPD to their class 
Let general purpose I2C/SMBus bus drivers add SPD to their class. Once
this is done, we will be able to tell the eeprom driver to only probe
for SPD EEPROMs and similar on these buses.

Note that I took a conservative approach here, adding I2C_CLASS_SPD to
many drivers that have no idea whether they can host SPD EEPROMs or not.
This is to make sure that the eeprom driver doesn't stop probing buses
where SPD EEPROMs or equivalent live.

So, bus driver maintainers and users should feel free to remove the SPD
class from drivers those buses never have SPD EEPROMs or they don't
want the eeprom driver to bind to them. Likewise, feel free to add the
SPD class to any bus driver I might have missed.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-07-14 22:38:29 +02:00

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/*
* Copyright (C) 2006-2007 PA Semi, Inc
*
* SMBus host driver for PA Semi PWRficient
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/kernel.h>
#include <linux/stddef.h>
#include <linux/sched.h>
#include <linux/i2c.h>
#include <linux/delay.h>
#include <asm/io.h>
static struct pci_driver pasemi_smb_driver;
struct pasemi_smbus {
struct pci_dev *dev;
struct i2c_adapter adapter;
unsigned long base;
int size;
};
/* Register offsets */
#define REG_MTXFIFO 0x00
#define REG_MRXFIFO 0x04
#define REG_SMSTA 0x14
#define REG_CTL 0x1c
/* Register defs */
#define MTXFIFO_READ 0x00000400
#define MTXFIFO_STOP 0x00000200
#define MTXFIFO_START 0x00000100
#define MTXFIFO_DATA_M 0x000000ff
#define MRXFIFO_EMPTY 0x00000100
#define MRXFIFO_DATA_M 0x000000ff
#define SMSTA_XEN 0x08000000
#define SMSTA_MTN 0x00200000
#define CTL_MRR 0x00000400
#define CTL_MTR 0x00000200
#define CTL_CLK_M 0x000000ff
#define CLK_100K_DIV 84
#define CLK_400K_DIV 21
static inline void reg_write(struct pasemi_smbus *smbus, int reg, int val)
{
dev_dbg(&smbus->dev->dev, "smbus write reg %lx val %08x\n",
smbus->base + reg, val);
outl(val, smbus->base + reg);
}
static inline int reg_read(struct pasemi_smbus *smbus, int reg)
{
int ret;
ret = inl(smbus->base + reg);
dev_dbg(&smbus->dev->dev, "smbus read reg %lx val %08x\n",
smbus->base + reg, ret);
return ret;
}
#define TXFIFO_WR(smbus, reg) reg_write((smbus), REG_MTXFIFO, (reg))
#define RXFIFO_RD(smbus) reg_read((smbus), REG_MRXFIFO)
static void pasemi_smb_clear(struct pasemi_smbus *smbus)
{
unsigned int status;
status = reg_read(smbus, REG_SMSTA);
reg_write(smbus, REG_SMSTA, status);
}
static unsigned int pasemi_smb_waitready(struct pasemi_smbus *smbus)
{
int timeout = 10;
unsigned int status;
status = reg_read(smbus, REG_SMSTA);
while (!(status & SMSTA_XEN) && timeout--) {
msleep(1);
status = reg_read(smbus, REG_SMSTA);
}
/* Got NACK? */
if (status & SMSTA_MTN)
return -ENXIO;
if (timeout < 0) {
dev_warn(&smbus->dev->dev, "Timeout, status 0x%08x\n", status);
reg_write(smbus, REG_SMSTA, status);
return -ETIME;
}
/* Clear XEN */
reg_write(smbus, REG_SMSTA, SMSTA_XEN);
return 0;
}
static int pasemi_i2c_xfer_msg(struct i2c_adapter *adapter,
struct i2c_msg *msg, int stop)
{
struct pasemi_smbus *smbus = adapter->algo_data;
int read, i, err;
u32 rd;
read = msg->flags & I2C_M_RD ? 1 : 0;
TXFIFO_WR(smbus, MTXFIFO_START | (msg->addr << 1) | read);
if (read) {
TXFIFO_WR(smbus, msg->len | MTXFIFO_READ |
(stop ? MTXFIFO_STOP : 0));
err = pasemi_smb_waitready(smbus);
if (err)
goto reset_out;
for (i = 0; i < msg->len; i++) {
rd = RXFIFO_RD(smbus);
if (rd & MRXFIFO_EMPTY) {
err = -ENODATA;
goto reset_out;
}
msg->buf[i] = rd & MRXFIFO_DATA_M;
}
} else {
for (i = 0; i < msg->len - 1; i++)
TXFIFO_WR(smbus, msg->buf[i]);
TXFIFO_WR(smbus, msg->buf[msg->len-1] |
(stop ? MTXFIFO_STOP : 0));
}
return 0;
reset_out:
reg_write(smbus, REG_CTL, (CTL_MTR | CTL_MRR |
(CLK_100K_DIV & CTL_CLK_M)));
return err;
}
static int pasemi_i2c_xfer(struct i2c_adapter *adapter,
struct i2c_msg *msgs, int num)
{
struct pasemi_smbus *smbus = adapter->algo_data;
int ret, i;
pasemi_smb_clear(smbus);
ret = 0;
for (i = 0; i < num && !ret; i++)
ret = pasemi_i2c_xfer_msg(adapter, &msgs[i], (i == (num - 1)));
return ret ? ret : num;
}
static int pasemi_smb_xfer(struct i2c_adapter *adapter,
u16 addr, unsigned short flags, char read_write, u8 command,
int size, union i2c_smbus_data *data)
{
struct pasemi_smbus *smbus = adapter->algo_data;
unsigned int rd;
int read_flag, err;
int len = 0, i;
/* All our ops take 8-bit shifted addresses */
addr <<= 1;
read_flag = read_write == I2C_SMBUS_READ;
pasemi_smb_clear(smbus);
switch (size) {
case I2C_SMBUS_QUICK:
TXFIFO_WR(smbus, addr | read_flag | MTXFIFO_START |
MTXFIFO_STOP);
break;
case I2C_SMBUS_BYTE:
TXFIFO_WR(smbus, addr | read_flag | MTXFIFO_START);
if (read_write)
TXFIFO_WR(smbus, 1 | MTXFIFO_STOP | MTXFIFO_READ);
else
TXFIFO_WR(smbus, MTXFIFO_STOP | command);
break;
case I2C_SMBUS_BYTE_DATA:
TXFIFO_WR(smbus, addr | MTXFIFO_START);
TXFIFO_WR(smbus, command);
if (read_write) {
TXFIFO_WR(smbus, addr | I2C_SMBUS_READ | MTXFIFO_START);
TXFIFO_WR(smbus, 1 | MTXFIFO_READ | MTXFIFO_STOP);
} else {
TXFIFO_WR(smbus, MTXFIFO_STOP | data->byte);
}
break;
case I2C_SMBUS_WORD_DATA:
TXFIFO_WR(smbus, addr | MTXFIFO_START);
TXFIFO_WR(smbus, command);
if (read_write) {
TXFIFO_WR(smbus, addr | I2C_SMBUS_READ | MTXFIFO_START);
TXFIFO_WR(smbus, 2 | MTXFIFO_READ | MTXFIFO_STOP);
} else {
TXFIFO_WR(smbus, data->word & MTXFIFO_DATA_M);
TXFIFO_WR(smbus, MTXFIFO_STOP | (data->word >> 8));
}
break;
case I2C_SMBUS_BLOCK_DATA:
TXFIFO_WR(smbus, addr | MTXFIFO_START);
TXFIFO_WR(smbus, command);
if (read_write) {
TXFIFO_WR(smbus, addr | I2C_SMBUS_READ | MTXFIFO_START);
TXFIFO_WR(smbus, 1 | MTXFIFO_READ);
rd = RXFIFO_RD(smbus);
len = min_t(u8, (rd & MRXFIFO_DATA_M),
I2C_SMBUS_BLOCK_MAX);
TXFIFO_WR(smbus, len | MTXFIFO_READ |
MTXFIFO_STOP);
} else {
len = min_t(u8, data->block[0], I2C_SMBUS_BLOCK_MAX);
TXFIFO_WR(smbus, len);
for (i = 1; i < len; i++)
TXFIFO_WR(smbus, data->block[i]);
TXFIFO_WR(smbus, data->block[len] | MTXFIFO_STOP);
}
break;
case I2C_SMBUS_PROC_CALL:
read_write = I2C_SMBUS_READ;
TXFIFO_WR(smbus, addr | MTXFIFO_START);
TXFIFO_WR(smbus, command);
TXFIFO_WR(smbus, data->word & MTXFIFO_DATA_M);
TXFIFO_WR(smbus, (data->word >> 8) & MTXFIFO_DATA_M);
TXFIFO_WR(smbus, addr | I2C_SMBUS_READ | MTXFIFO_START);
TXFIFO_WR(smbus, 2 | MTXFIFO_STOP | MTXFIFO_READ);
break;
case I2C_SMBUS_BLOCK_PROC_CALL:
len = min_t(u8, data->block[0], I2C_SMBUS_BLOCK_MAX - 1);
read_write = I2C_SMBUS_READ;
TXFIFO_WR(smbus, addr | MTXFIFO_START);
TXFIFO_WR(smbus, command);
TXFIFO_WR(smbus, len);
for (i = 1; i <= len; i++)
TXFIFO_WR(smbus, data->block[i]);
TXFIFO_WR(smbus, addr | I2C_SMBUS_READ);
TXFIFO_WR(smbus, MTXFIFO_READ | 1);
rd = RXFIFO_RD(smbus);
len = min_t(u8, (rd & MRXFIFO_DATA_M),
I2C_SMBUS_BLOCK_MAX - len);
TXFIFO_WR(smbus, len | MTXFIFO_READ | MTXFIFO_STOP);
break;
default:
dev_warn(&adapter->dev, "Unsupported transaction %d\n", size);
return -EINVAL;
}
err = pasemi_smb_waitready(smbus);
if (err)
goto reset_out;
if (read_write == I2C_SMBUS_WRITE)
return 0;
switch (size) {
case I2C_SMBUS_BYTE:
case I2C_SMBUS_BYTE_DATA:
rd = RXFIFO_RD(smbus);
if (rd & MRXFIFO_EMPTY) {
err = -ENODATA;
goto reset_out;
}
data->byte = rd & MRXFIFO_DATA_M;
break;
case I2C_SMBUS_WORD_DATA:
case I2C_SMBUS_PROC_CALL:
rd = RXFIFO_RD(smbus);
if (rd & MRXFIFO_EMPTY) {
err = -ENODATA;
goto reset_out;
}
data->word = rd & MRXFIFO_DATA_M;
rd = RXFIFO_RD(smbus);
if (rd & MRXFIFO_EMPTY) {
err = -ENODATA;
goto reset_out;
}
data->word |= (rd & MRXFIFO_DATA_M) << 8;
break;
case I2C_SMBUS_BLOCK_DATA:
case I2C_SMBUS_BLOCK_PROC_CALL:
data->block[0] = len;
for (i = 1; i <= len; i ++) {
rd = RXFIFO_RD(smbus);
if (rd & MRXFIFO_EMPTY) {
err = -ENODATA;
goto reset_out;
}
data->block[i] = rd & MRXFIFO_DATA_M;
}
break;
}
return 0;
reset_out:
reg_write(smbus, REG_CTL, (CTL_MTR | CTL_MRR |
(CLK_100K_DIV & CTL_CLK_M)));
return err;
}
static u32 pasemi_smb_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_BLOCK_DATA | I2C_FUNC_SMBUS_PROC_CALL |
I2C_FUNC_SMBUS_BLOCK_PROC_CALL | I2C_FUNC_I2C;
}
static const struct i2c_algorithm smbus_algorithm = {
.master_xfer = pasemi_i2c_xfer,
.smbus_xfer = pasemi_smb_xfer,
.functionality = pasemi_smb_func,
};
static int __devinit pasemi_smb_probe(struct pci_dev *dev,
const struct pci_device_id *id)
{
struct pasemi_smbus *smbus;
int error;
if (!(pci_resource_flags(dev, 0) & IORESOURCE_IO))
return -ENODEV;
smbus = kzalloc(sizeof(struct pasemi_smbus), GFP_KERNEL);
if (!smbus)
return -ENOMEM;
smbus->dev = dev;
smbus->base = pci_resource_start(dev, 0);
smbus->size = pci_resource_len(dev, 0);
if (!request_region(smbus->base, smbus->size,
pasemi_smb_driver.name)) {
error = -EBUSY;
goto out_kfree;
}
smbus->adapter.owner = THIS_MODULE;
snprintf(smbus->adapter.name, sizeof(smbus->adapter.name),
"PA Semi SMBus adapter at 0x%lx", smbus->base);
smbus->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
smbus->adapter.algo = &smbus_algorithm;
smbus->adapter.algo_data = smbus;
smbus->adapter.nr = PCI_FUNC(dev->devfn);
/* set up the sysfs linkage to our parent device */
smbus->adapter.dev.parent = &dev->dev;
reg_write(smbus, REG_CTL, (CTL_MTR | CTL_MRR |
(CLK_100K_DIV & CTL_CLK_M)));
error = i2c_add_numbered_adapter(&smbus->adapter);
if (error)
goto out_release_region;
pci_set_drvdata(dev, smbus);
return 0;
out_release_region:
release_region(smbus->base, smbus->size);
out_kfree:
kfree(smbus);
return error;
}
static void __devexit pasemi_smb_remove(struct pci_dev *dev)
{
struct pasemi_smbus *smbus = pci_get_drvdata(dev);
i2c_del_adapter(&smbus->adapter);
release_region(smbus->base, smbus->size);
kfree(smbus);
}
static struct pci_device_id pasemi_smb_ids[] = {
{ PCI_DEVICE(0x1959, 0xa003) },
{ 0, }
};
MODULE_DEVICE_TABLE(pci, pasemi_smb_ids);
static struct pci_driver pasemi_smb_driver = {
.name = "i2c-pasemi",
.id_table = pasemi_smb_ids,
.probe = pasemi_smb_probe,
.remove = __devexit_p(pasemi_smb_remove),
};
static int __init pasemi_smb_init(void)
{
return pci_register_driver(&pasemi_smb_driver);
}
static void __exit pasemi_smb_exit(void)
{
pci_unregister_driver(&pasemi_smb_driver);
}
MODULE_LICENSE("GPL");
MODULE_AUTHOR ("Olof Johansson <olof@lixom.net>");
MODULE_DESCRIPTION("PA Semi PWRficient SMBus driver");
module_init(pasemi_smb_init);
module_exit(pasemi_smb_exit);
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