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linux-stable/drivers/misc/ics932s401.c
Darrick J. Wong a412ae3fb9 ics932s401: new clock generator chip driver 
The ics932s401 is a clock generator chip.  This driver allows users to
read the current clock outputs.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-12 17:17:18 -08:00

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/*
* A driver for the Integrated Circuits ICS932S401
* Copyright (C) 2008 IBM
*
* Author: Darrick J. Wong <djwong@us.ibm.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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/module.h>
#include <linux/jiffies.h>
#include <linux/i2c.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include <linux/log2.h>
/* Addresses to scan */
static const unsigned short normal_i2c[] = { 0x69, I2C_CLIENT_END };
/* Insmod parameters */
I2C_CLIENT_INSMOD_1(ics932s401);
/* ICS932S401 registers */
#define ICS932S401_REG_CFG2 0x01
#define ICS932S401_CFG1_SPREAD 0x01
#define ICS932S401_REG_CFG7 0x06
#define ICS932S401_FS_MASK 0x07
#define ICS932S401_REG_VENDOR_REV 0x07
#define ICS932S401_VENDOR 1
#define ICS932S401_VENDOR_MASK 0x0F
#define ICS932S401_REV 4
#define ICS932S401_REV_SHIFT 4
#define ICS932S401_REG_DEVICE 0x09
#define ICS932S401_DEVICE 11
#define ICS932S401_REG_CTRL 0x0A
#define ICS932S401_MN_ENABLED 0x80
#define ICS932S401_CPU_ALT 0x04
#define ICS932S401_SRC_ALT 0x08
#define ICS932S401_REG_CPU_M_CTRL 0x0B
#define ICS932S401_M_MASK 0x3F
#define ICS932S401_REG_CPU_N_CTRL 0x0C
#define ICS932S401_REG_CPU_SPREAD1 0x0D
#define ICS932S401_REG_CPU_SPREAD2 0x0E
#define ICS932S401_SPREAD_MASK 0x7FFF
#define ICS932S401_REG_SRC_M_CTRL 0x0F
#define ICS932S401_REG_SRC_N_CTRL 0x10
#define ICS932S401_REG_SRC_SPREAD1 0x11
#define ICS932S401_REG_SRC_SPREAD2 0x12
#define ICS932S401_REG_CPU_DIVISOR 0x13
#define ICS932S401_CPU_DIVISOR_SHIFT 4
#define ICS932S401_REG_PCISRC_DIVISOR 0x14
#define ICS932S401_SRC_DIVISOR_MASK 0x0F
#define ICS932S401_PCI_DIVISOR_SHIFT 4
/* Base clock is 14.318MHz */
#define BASE_CLOCK 14318
#define NUM_REGS 21
#define NUM_MIRRORED_REGS 15
static int regs_to_copy[NUM_MIRRORED_REGS] = {
ICS932S401_REG_CFG2,
ICS932S401_REG_CFG7,
ICS932S401_REG_VENDOR_REV,
ICS932S401_REG_DEVICE,
ICS932S401_REG_CTRL,
ICS932S401_REG_CPU_M_CTRL,
ICS932S401_REG_CPU_N_CTRL,
ICS932S401_REG_CPU_SPREAD1,
ICS932S401_REG_CPU_SPREAD2,
ICS932S401_REG_SRC_M_CTRL,
ICS932S401_REG_SRC_N_CTRL,
ICS932S401_REG_SRC_SPREAD1,
ICS932S401_REG_SRC_SPREAD2,
ICS932S401_REG_CPU_DIVISOR,
ICS932S401_REG_PCISRC_DIVISOR,
};
/* How often do we reread sensors values? (In jiffies) */
#define SENSOR_REFRESH_INTERVAL (2 * HZ)
/* How often do we reread sensor limit values? (In jiffies) */
#define LIMIT_REFRESH_INTERVAL (60 * HZ)
struct ics932s401_data {
struct attribute_group attrs;
struct mutex lock;
char sensors_valid;
unsigned long sensors_last_updated; /* In jiffies */
u8 regs[NUM_REGS];
};
static int ics932s401_probe(struct i2c_client *client,
const struct i2c_device_id *id);
static int ics932s401_detect(struct i2c_client *client, int kind,
struct i2c_board_info *info);
static int ics932s401_remove(struct i2c_client *client);
static const struct i2c_device_id ics932s401_id[] = {
{ "ics932s401", ics932s401 },
{ }
};
MODULE_DEVICE_TABLE(i2c, ics932s401_id);
static struct i2c_driver ics932s401_driver = {
.class = I2C_CLASS_HWMON,
.driver = {
.name = "ics932s401",
},
.probe = ics932s401_probe,
.remove = ics932s401_remove,
.id_table = ics932s401_id,
.detect = ics932s401_detect,
.address_data = &addr_data,
};
static struct ics932s401_data *ics932s401_update_device(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct ics932s401_data *data = i2c_get_clientdata(client);
unsigned long local_jiffies = jiffies;
int i, temp;
mutex_lock(&data->lock);
if (time_before(local_jiffies, data->sensors_last_updated +
SENSOR_REFRESH_INTERVAL)
&& data->sensors_valid)
goto out;
/*
* Each register must be read as a word and then right shifted 8 bits.
* Not really sure why this is; setting the "byte count programming"
* register to 1 does not fix this problem.
*/
for (i = 0; i < NUM_MIRRORED_REGS; i++) {
temp = i2c_smbus_read_word_data(client, regs_to_copy[i]);
data->regs[regs_to_copy[i]] = temp >> 8;
}
data->sensors_last_updated = local_jiffies;
data->sensors_valid = 1;
out:
mutex_unlock(&data->lock);
return data;
}
static ssize_t show_spread_enabled(struct device *dev,
struct device_attribute *devattr,
char *buf)
{
struct ics932s401_data *data = ics932s401_update_device(dev);
if (data->regs[ICS932S401_REG_CFG2] & ICS932S401_CFG1_SPREAD)
return sprintf(buf, "1\n");
return sprintf(buf, "0\n");
}
/* bit to cpu khz map */
static const int fs_speeds[] = {
266666,
133333,
200000,
166666,
333333,
100000,
400000,
0,
};
/* clock divisor map */
static const int divisors[] = {2, 3, 5, 15, 4, 6, 10, 30, 8, 12, 20, 60, 16,
24, 40, 120};
/* Calculate CPU frequency from the M/N registers. */
static int calculate_cpu_freq(struct ics932s401_data *data)
{
int m, n, freq;
m = data->regs[ICS932S401_REG_CPU_M_CTRL] & ICS932S401_M_MASK;
n = data->regs[ICS932S401_REG_CPU_N_CTRL];
/* Pull in bits 8 & 9 from the M register */
n |= ((int)data->regs[ICS932S401_REG_CPU_M_CTRL] & 0x80) << 1;
n |= ((int)data->regs[ICS932S401_REG_CPU_M_CTRL] & 0x40) << 3;
freq = BASE_CLOCK * (n + 8) / (m + 2);
freq /= divisors[data->regs[ICS932S401_REG_CPU_DIVISOR] >>
ICS932S401_CPU_DIVISOR_SHIFT];
return freq;
}
static ssize_t show_cpu_clock(struct device *dev,
struct device_attribute *devattr,
char *buf)
{
struct ics932s401_data *data = ics932s401_update_device(dev);
return sprintf(buf, "%d\n", calculate_cpu_freq(data));
}
static ssize_t show_cpu_clock_sel(struct device *dev,
struct device_attribute *devattr,
char *buf)
{
struct ics932s401_data *data = ics932s401_update_device(dev);
int freq;
if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_MN_ENABLED)
freq = calculate_cpu_freq(data);
else {
/* Freq is neatly wrapped up for us */
int fid = data->regs[ICS932S401_REG_CFG7] & ICS932S401_FS_MASK;
freq = fs_speeds[fid];
if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_CPU_ALT) {
switch (freq) {
case 166666:
freq = 160000;
break;
case 333333:
freq = 320000;
break;
}
}
}
return sprintf(buf, "%d\n", freq);
}
/* Calculate SRC frequency from the M/N registers. */
static int calculate_src_freq(struct ics932s401_data *data)
{
int m, n, freq;
m = data->regs[ICS932S401_REG_SRC_M_CTRL] & ICS932S401_M_MASK;
n = data->regs[ICS932S401_REG_SRC_N_CTRL];
/* Pull in bits 8 & 9 from the M register */
n |= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x80) << 1;
n |= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x40) << 3;
freq = BASE_CLOCK * (n + 8) / (m + 2);
freq /= divisors[data->regs[ICS932S401_REG_PCISRC_DIVISOR] &
ICS932S401_SRC_DIVISOR_MASK];
return freq;
}
static ssize_t show_src_clock(struct device *dev,
struct device_attribute *devattr,
char *buf)
{
struct ics932s401_data *data = ics932s401_update_device(dev);
return sprintf(buf, "%d\n", calculate_src_freq(data));
}
static ssize_t show_src_clock_sel(struct device *dev,
struct device_attribute *devattr,
char *buf)
{
struct ics932s401_data *data = ics932s401_update_device(dev);
int freq;
if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_MN_ENABLED)
freq = calculate_src_freq(data);
else
/* Freq is neatly wrapped up for us */
if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_CPU_ALT &&
data->regs[ICS932S401_REG_CTRL] & ICS932S401_SRC_ALT)
freq = 96000;
else
freq = 100000;
return sprintf(buf, "%d\n", freq);
}
/* Calculate PCI frequency from the SRC M/N registers. */
static int calculate_pci_freq(struct ics932s401_data *data)
{
int m, n, freq;
m = data->regs[ICS932S401_REG_SRC_M_CTRL] & ICS932S401_M_MASK;
n = data->regs[ICS932S401_REG_SRC_N_CTRL];
/* Pull in bits 8 & 9 from the M register */
n |= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x80) << 1;
n |= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x40) << 3;
freq = BASE_CLOCK * (n + 8) / (m + 2);
freq /= divisors[data->regs[ICS932S401_REG_PCISRC_DIVISOR] >>
ICS932S401_PCI_DIVISOR_SHIFT];
return freq;
}
static ssize_t show_pci_clock(struct device *dev,
struct device_attribute *devattr,
char *buf)
{
struct ics932s401_data *data = ics932s401_update_device(dev);
return sprintf(buf, "%d\n", calculate_pci_freq(data));
}
static ssize_t show_pci_clock_sel(struct device *dev,
struct device_attribute *devattr,
char *buf)
{
struct ics932s401_data *data = ics932s401_update_device(dev);
int freq;
if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_MN_ENABLED)
freq = calculate_pci_freq(data);
else
freq = 33333;
return sprintf(buf, "%d\n", freq);
}
static ssize_t show_value(struct device *dev,
struct device_attribute *devattr,
char *buf);
static ssize_t show_spread(struct device *dev,
struct device_attribute *devattr,
char *buf);
static DEVICE_ATTR(spread_enabled, S_IRUGO, show_spread_enabled, NULL);
static DEVICE_ATTR(cpu_clock_selection, S_IRUGO, show_cpu_clock_sel, NULL);
static DEVICE_ATTR(cpu_clock, S_IRUGO, show_cpu_clock, NULL);
static DEVICE_ATTR(src_clock_selection, S_IRUGO, show_src_clock_sel, NULL);
static DEVICE_ATTR(src_clock, S_IRUGO, show_src_clock, NULL);
static DEVICE_ATTR(pci_clock_selection, S_IRUGO, show_pci_clock_sel, NULL);
static DEVICE_ATTR(pci_clock, S_IRUGO, show_pci_clock, NULL);
static DEVICE_ATTR(usb_clock, S_IRUGO, show_value, NULL);
static DEVICE_ATTR(ref_clock, S_IRUGO, show_value, NULL);
static DEVICE_ATTR(cpu_spread, S_IRUGO, show_spread, NULL);
static DEVICE_ATTR(src_spread, S_IRUGO, show_spread, NULL);
static struct attribute *ics932s401_attr[] =
{
&dev_attr_spread_enabled.attr,
&dev_attr_cpu_clock_selection.attr,
&dev_attr_cpu_clock.attr,
&dev_attr_src_clock_selection.attr,
&dev_attr_src_clock.attr,
&dev_attr_pci_clock_selection.attr,
&dev_attr_pci_clock.attr,
&dev_attr_usb_clock.attr,
&dev_attr_ref_clock.attr,
&dev_attr_cpu_spread.attr,
&dev_attr_src_spread.attr,
NULL
};
static ssize_t show_value(struct device *dev,
struct device_attribute *devattr,
char *buf)
{
int x;
if (devattr == &dev_attr_usb_clock)
x = 48000;
else if (devattr == &dev_attr_ref_clock)
x = BASE_CLOCK;
else
BUG();
return sprintf(buf, "%d\n", x);
}
static ssize_t show_spread(struct device *dev,
struct device_attribute *devattr,
char *buf)
{
struct ics932s401_data *data = ics932s401_update_device(dev);
int reg;
unsigned long val;
if (!(data->regs[ICS932S401_REG_CFG2] & ICS932S401_CFG1_SPREAD))
return sprintf(buf, "0%%\n");
if (devattr == &dev_attr_src_spread)
reg = ICS932S401_REG_SRC_SPREAD1;
else if (devattr == &dev_attr_cpu_spread)
reg = ICS932S401_REG_CPU_SPREAD1;
else
BUG();
val = data->regs[reg] | (data->regs[reg + 1] << 8);
val &= ICS932S401_SPREAD_MASK;
/* Scale 0..2^14 to -0.5. */
val = 500000 * val / 16384;
return sprintf(buf, "-0.%lu%%\n", val);
}
/* Return 0 if detection is successful, -ENODEV otherwise */
static int ics932s401_detect(struct i2c_client *client, int kind,
struct i2c_board_info *info)
{
struct i2c_adapter *adapter = client->adapter;
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
return -ENODEV;
if (kind <= 0) {
int vendor, device, revision;
vendor = i2c_smbus_read_word_data(client,
ICS932S401_REG_VENDOR_REV);
vendor >>= 8;
revision = vendor >> ICS932S401_REV_SHIFT;
vendor &= ICS932S401_VENDOR_MASK;
if (vendor != ICS932S401_VENDOR)
return -ENODEV;
device = i2c_smbus_read_word_data(client,
ICS932S401_REG_DEVICE);
device >>= 8;
if (device != ICS932S401_DEVICE)
return -ENODEV;
if (revision != ICS932S401_REV)
dev_info(&adapter->dev, "Unknown revision %d\n",
revision);
} else
dev_dbg(&adapter->dev, "detection forced\n");
strlcpy(info->type, "ics932s401", I2C_NAME_SIZE);
return 0;
}
static int ics932s401_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct ics932s401_data *data;
int err;
data = kzalloc(sizeof(struct ics932s401_data), GFP_KERNEL);
if (!data) {
err = -ENOMEM;
goto exit;
}
i2c_set_clientdata(client, data);
mutex_init(&data->lock);
dev_info(&client->dev, "%s chip found\n", client->name);
/* Register sysfs hooks */
data->attrs.attrs = ics932s401_attr;
err = sysfs_create_group(&client->dev.kobj, &data->attrs);
if (err)
goto exit_free;
return 0;
exit_free:
kfree(data);
exit:
return err;
}
static int ics932s401_remove(struct i2c_client *client)
{
struct ics932s401_data *data = i2c_get_clientdata(client);
sysfs_remove_group(&client->dev.kobj, &data->attrs);
kfree(data);
return 0;
}
static int __init ics932s401_init(void)
{
return i2c_add_driver(&ics932s401_driver);
}
static void __exit ics932s401_exit(void)
{
i2c_del_driver(&ics932s401_driver);
}
MODULE_AUTHOR("Darrick J. Wong <djwong@us.ibm.com>");
MODULE_DESCRIPTION("ICS932S401 driver");
MODULE_LICENSE("GPL");
module_init(ics932s401_init);
module_exit(ics932s401_exit);
/* IBM IntelliStation Z30 */
MODULE_ALIAS("dmi:bvnIBM:*:rn9228:*");
MODULE_ALIAS("dmi:bvnIBM:*:rn9232:*");
/* IBM x3650/x3550 */
MODULE_ALIAS("dmi:bvnIBM:*:pnIBMSystemx3650*");
MODULE_ALIAS("dmi:bvnIBM:*:pnIBMSystemx3550*");
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