linux/drivers/hwmon/atxp1.c
Jean Delvare 6cf0a91ebe hwmon: Avoid initializing the same field twice
All hwmon drivers allocate their data structure with some form of
kzalloc, so setting data fields to zero explicitly is a waste of time.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
2014-04-04 18:01:34 +02:00

390 lines
9.1 KiB
C

/*
* atxp1.c - kernel module for setting CPU VID and general purpose
* I/Os using the Attansic ATXP1 chip.
*
* 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.
*
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/jiffies.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/hwmon-vid.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/sysfs.h>
#include <linux/slab.h>
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("System voltages control via Attansic ATXP1");
MODULE_VERSION("0.6.3");
MODULE_AUTHOR("Sebastian Witt <se.witt@gmx.net>");
#define ATXP1_VID 0x00
#define ATXP1_CVID 0x01
#define ATXP1_GPIO1 0x06
#define ATXP1_GPIO2 0x0a
#define ATXP1_VIDENA 0x20
#define ATXP1_VIDMASK 0x1f
#define ATXP1_GPIO1MASK 0x0f
static const unsigned short normal_i2c[] = { 0x37, 0x4e, I2C_CLIENT_END };
static int atxp1_probe(struct i2c_client *client,
const struct i2c_device_id *id);
static int atxp1_remove(struct i2c_client *client);
static struct atxp1_data *atxp1_update_device(struct device *dev);
static int atxp1_detect(struct i2c_client *client, struct i2c_board_info *info);
static const struct i2c_device_id atxp1_id[] = {
{ "atxp1", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, atxp1_id);
static struct i2c_driver atxp1_driver = {
.class = I2C_CLASS_HWMON,
.driver = {
.name = "atxp1",
},
.probe = atxp1_probe,
.remove = atxp1_remove,
.id_table = atxp1_id,
.detect = atxp1_detect,
.address_list = normal_i2c,
};
struct atxp1_data {
struct device *hwmon_dev;
struct mutex update_lock;
unsigned long last_updated;
u8 valid;
struct {
u8 vid; /* VID output register */
u8 cpu_vid; /* VID input from CPU */
u8 gpio1; /* General purpose I/O register 1 */
u8 gpio2; /* General purpose I/O register 2 */
} reg;
u8 vrm; /* Detected CPU VRM */
};
static struct atxp1_data *atxp1_update_device(struct device *dev)
{
struct i2c_client *client;
struct atxp1_data *data;
client = to_i2c_client(dev);
data = i2c_get_clientdata(client);
mutex_lock(&data->update_lock);
if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
/* Update local register data */
data->reg.vid = i2c_smbus_read_byte_data(client, ATXP1_VID);
data->reg.cpu_vid = i2c_smbus_read_byte_data(client,
ATXP1_CVID);
data->reg.gpio1 = i2c_smbus_read_byte_data(client, ATXP1_GPIO1);
data->reg.gpio2 = i2c_smbus_read_byte_data(client, ATXP1_GPIO2);
data->valid = 1;
}
mutex_unlock(&data->update_lock);
return data;
}
/* sys file functions for cpu0_vid */
static ssize_t atxp1_showvcore(struct device *dev,
struct device_attribute *attr, char *buf)
{
int size;
struct atxp1_data *data;
data = atxp1_update_device(dev);
size = sprintf(buf, "%d\n", vid_from_reg(data->reg.vid & ATXP1_VIDMASK,
data->vrm));
return size;
}
static ssize_t atxp1_storevcore(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct atxp1_data *data;
struct i2c_client *client;
int vid, cvid;
unsigned long vcore;
int err;
client = to_i2c_client(dev);
data = atxp1_update_device(dev);
err = kstrtoul(buf, 10, &vcore);
if (err)
return err;
vcore /= 25;
vcore *= 25;
/* Calculate VID */
vid = vid_to_reg(vcore, data->vrm);
if (vid < 0) {
dev_err(dev, "VID calculation failed.\n");
return vid;
}
/*
* If output enabled, use control register value.
* Otherwise original CPU VID
*/
if (data->reg.vid & ATXP1_VIDENA)
cvid = data->reg.vid & ATXP1_VIDMASK;
else
cvid = data->reg.cpu_vid;
/* Nothing changed, aborting */
if (vid == cvid)
return count;
dev_dbg(dev, "Setting VCore to %d mV (0x%02x)\n", (int)vcore, vid);
/* Write every 25 mV step to increase stability */
if (cvid > vid) {
for (; cvid >= vid; cvid--)
i2c_smbus_write_byte_data(client,
ATXP1_VID, cvid | ATXP1_VIDENA);
} else {
for (; cvid <= vid; cvid++)
i2c_smbus_write_byte_data(client,
ATXP1_VID, cvid | ATXP1_VIDENA);
}
data->valid = 0;
return count;
}
/*
* CPU core reference voltage
* unit: millivolt
*/
static DEVICE_ATTR(cpu0_vid, S_IRUGO | S_IWUSR, atxp1_showvcore,
atxp1_storevcore);
/* sys file functions for GPIO1 */
static ssize_t atxp1_showgpio1(struct device *dev,
struct device_attribute *attr, char *buf)
{
int size;
struct atxp1_data *data;
data = atxp1_update_device(dev);
size = sprintf(buf, "0x%02x\n", data->reg.gpio1 & ATXP1_GPIO1MASK);
return size;
}
static ssize_t atxp1_storegpio1(struct device *dev,
struct device_attribute *attr, const char *buf,
size_t count)
{
struct atxp1_data *data;
struct i2c_client *client;
unsigned long value;
int err;
client = to_i2c_client(dev);
data = atxp1_update_device(dev);
err = kstrtoul(buf, 16, &value);
if (err)
return err;
value &= ATXP1_GPIO1MASK;
if (value != (data->reg.gpio1 & ATXP1_GPIO1MASK)) {
dev_info(dev, "Writing 0x%x to GPIO1.\n", (unsigned int)value);
i2c_smbus_write_byte_data(client, ATXP1_GPIO1, value);
data->valid = 0;
}
return count;
}
/*
* GPIO1 data register
* unit: Four bit as hex (e.g. 0x0f)
*/
static DEVICE_ATTR(gpio1, S_IRUGO | S_IWUSR, atxp1_showgpio1, atxp1_storegpio1);
/* sys file functions for GPIO2 */
static ssize_t atxp1_showgpio2(struct device *dev,
struct device_attribute *attr, char *buf)
{
int size;
struct atxp1_data *data;
data = atxp1_update_device(dev);
size = sprintf(buf, "0x%02x\n", data->reg.gpio2);
return size;
}
static ssize_t atxp1_storegpio2(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct atxp1_data *data = atxp1_update_device(dev);
struct i2c_client *client = to_i2c_client(dev);
unsigned long value;
int err;
err = kstrtoul(buf, 16, &value);
if (err)
return err;
value &= 0xff;
if (value != data->reg.gpio2) {
dev_info(dev, "Writing 0x%x to GPIO1.\n", (unsigned int)value);
i2c_smbus_write_byte_data(client, ATXP1_GPIO2, value);
data->valid = 0;
}
return count;
}
/*
* GPIO2 data register
* unit: Eight bit as hex (e.g. 0xff)
*/
static DEVICE_ATTR(gpio2, S_IRUGO | S_IWUSR, atxp1_showgpio2, atxp1_storegpio2);
static struct attribute *atxp1_attributes[] = {
&dev_attr_gpio1.attr,
&dev_attr_gpio2.attr,
&dev_attr_cpu0_vid.attr,
NULL
};
static const struct attribute_group atxp1_group = {
.attrs = atxp1_attributes,
};
/* Return 0 if detection is successful, -ENODEV otherwise */
static int atxp1_detect(struct i2c_client *new_client,
struct i2c_board_info *info)
{
struct i2c_adapter *adapter = new_client->adapter;
u8 temp;
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
return -ENODEV;
/* Detect ATXP1, checking if vendor ID registers are all zero */
if (!((i2c_smbus_read_byte_data(new_client, 0x3e) == 0) &&
(i2c_smbus_read_byte_data(new_client, 0x3f) == 0) &&
(i2c_smbus_read_byte_data(new_client, 0xfe) == 0) &&
(i2c_smbus_read_byte_data(new_client, 0xff) == 0)))
return -ENODEV;
/*
* No vendor ID, now checking if registers 0x10,0x11 (non-existent)
* showing the same as register 0x00
*/
temp = i2c_smbus_read_byte_data(new_client, 0x00);
if (!((i2c_smbus_read_byte_data(new_client, 0x10) == temp) &&
(i2c_smbus_read_byte_data(new_client, 0x11) == temp)))
return -ENODEV;
/* Get VRM */
temp = vid_which_vrm();
if ((temp != 90) && (temp != 91)) {
dev_err(&adapter->dev, "atxp1: Not supporting VRM %d.%d\n",
temp / 10, temp % 10);
return -ENODEV;
}
strlcpy(info->type, "atxp1", I2C_NAME_SIZE);
return 0;
}
static int atxp1_probe(struct i2c_client *new_client,
const struct i2c_device_id *id)
{
struct atxp1_data *data;
int err;
data = devm_kzalloc(&new_client->dev, sizeof(struct atxp1_data),
GFP_KERNEL);
if (!data)
return -ENOMEM;
/* Get VRM */
data->vrm = vid_which_vrm();
i2c_set_clientdata(new_client, data);
mutex_init(&data->update_lock);
/* Register sysfs hooks */
err = sysfs_create_group(&new_client->dev.kobj, &atxp1_group);
if (err)
return err;
data->hwmon_dev = hwmon_device_register(&new_client->dev);
if (IS_ERR(data->hwmon_dev)) {
err = PTR_ERR(data->hwmon_dev);
goto exit_remove_files;
}
dev_info(&new_client->dev, "Using VRM: %d.%d\n",
data->vrm / 10, data->vrm % 10);
return 0;
exit_remove_files:
sysfs_remove_group(&new_client->dev.kobj, &atxp1_group);
return err;
};
static int atxp1_remove(struct i2c_client *client)
{
struct atxp1_data *data = i2c_get_clientdata(client);
hwmon_device_unregister(data->hwmon_dev);
sysfs_remove_group(&client->dev.kobj, &atxp1_group);
return 0;
};
module_i2c_driver(atxp1_driver);