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linux/drivers/hwmon/ads1015.c
Guenter Roeck 363434b5dc hwmon: (ads1015) Fix file leak in probe function
An error while creating sysfs attribute files in the driver's probe function
results in an error abort, but already created files are not removed. This patch
fixes the problem.

Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Cc: stable@vger.kernel.org # 3.0+
Cc: Dirk Eibach <eibach@gdsys.de>
Acked-by: Jean Delvare <khali@linux-fr.org>
2012-02-23 06:47:41 -08:00

324 lines
8.1 KiB
C

/*
* ads1015.c - lm_sensors driver for ads1015 12-bit 4-input ADC
* (C) Copyright 2010
* Dirk Eibach, Guntermann & Drunck GmbH <eibach@gdsys.de>
*
* Based on the ads7828 driver by Steve Hardy.
*
* Datasheet available at: http://focus.ti.com/lit/ds/symlink/ads1015.pdf
*
* 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/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/i2c/ads1015.h>
/* ADS1015 registers */
enum {
ADS1015_CONVERSION = 0,
ADS1015_CONFIG = 1,
};
/* PGA fullscale voltages in mV */
static const unsigned int fullscale_table[8] = {
6144, 4096, 2048, 1024, 512, 256, 256, 256 };
/* Data rates in samples per second */
static const unsigned int data_rate_table[8] = {
128, 250, 490, 920, 1600, 2400, 3300, 3300 };
#define ADS1015_DEFAULT_CHANNELS 0xff
#define ADS1015_DEFAULT_PGA 2
#define ADS1015_DEFAULT_DATA_RATE 4
struct ads1015_data {
struct device *hwmon_dev;
struct mutex update_lock; /* mutex protect updates */
struct ads1015_channel_data channel_data[ADS1015_CHANNELS];
};
static int ads1015_read_value(struct i2c_client *client, unsigned int channel,
int *value)
{
u16 config;
s16 conversion;
struct ads1015_data *data = i2c_get_clientdata(client);
unsigned int pga = data->channel_data[channel].pga;
int fullscale;
unsigned int data_rate = data->channel_data[channel].data_rate;
unsigned int conversion_time_ms;
int res;
mutex_lock(&data->update_lock);
/* get channel parameters */
res = i2c_smbus_read_word_swapped(client, ADS1015_CONFIG);
if (res < 0)
goto err_unlock;
config = res;
fullscale = fullscale_table[pga];
conversion_time_ms = DIV_ROUND_UP(1000, data_rate_table[data_rate]);
/* setup and start single conversion */
config &= 0x001f;
config |= (1 << 15) | (1 << 8);
config |= (channel & 0x0007) << 12;
config |= (pga & 0x0007) << 9;
config |= (data_rate & 0x0007) << 5;
res = i2c_smbus_write_word_swapped(client, ADS1015_CONFIG, config);
if (res < 0)
goto err_unlock;
/* wait until conversion finished */
msleep(conversion_time_ms);
res = i2c_smbus_read_word_swapped(client, ADS1015_CONFIG);
if (res < 0)
goto err_unlock;
config = res;
if (!(config & (1 << 15))) {
/* conversion not finished in time */
res = -EIO;
goto err_unlock;
}
res = i2c_smbus_read_word_swapped(client, ADS1015_CONVERSION);
if (res < 0)
goto err_unlock;
conversion = res;
mutex_unlock(&data->update_lock);
*value = DIV_ROUND_CLOSEST(conversion * fullscale, 0x7ff0);
return 0;
err_unlock:
mutex_unlock(&data->update_lock);
return res;
}
/* sysfs callback function */
static ssize_t show_in(struct device *dev, struct device_attribute *da,
char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
struct i2c_client *client = to_i2c_client(dev);
int in;
int res;
res = ads1015_read_value(client, attr->index, &in);
return (res < 0) ? res : sprintf(buf, "%d\n", in);
}
static const struct sensor_device_attribute ads1015_in[] = {
SENSOR_ATTR(in0_input, S_IRUGO, show_in, NULL, 0),
SENSOR_ATTR(in1_input, S_IRUGO, show_in, NULL, 1),
SENSOR_ATTR(in2_input, S_IRUGO, show_in, NULL, 2),
SENSOR_ATTR(in3_input, S_IRUGO, show_in, NULL, 3),
SENSOR_ATTR(in4_input, S_IRUGO, show_in, NULL, 4),
SENSOR_ATTR(in5_input, S_IRUGO, show_in, NULL, 5),
SENSOR_ATTR(in6_input, S_IRUGO, show_in, NULL, 6),
SENSOR_ATTR(in7_input, S_IRUGO, show_in, NULL, 7),
};
/*
* Driver interface
*/
static int ads1015_remove(struct i2c_client *client)
{
struct ads1015_data *data = i2c_get_clientdata(client);
int k;
hwmon_device_unregister(data->hwmon_dev);
for (k = 0; k < ADS1015_CHANNELS; ++k)
device_remove_file(&client->dev, &ads1015_in[k].dev_attr);
kfree(data);
return 0;
}
#ifdef CONFIG_OF
static int ads1015_get_channels_config_of(struct i2c_client *client)
{
struct ads1015_data *data = i2c_get_clientdata(client);
struct device_node *node;
if (!client->dev.of_node
|| !of_get_next_child(client->dev.of_node, NULL))
return -EINVAL;
for_each_child_of_node(client->dev.of_node, node) {
const __be32 *property;
int len;
unsigned int channel;
unsigned int pga = ADS1015_DEFAULT_PGA;
unsigned int data_rate = ADS1015_DEFAULT_DATA_RATE;
property = of_get_property(node, "reg", &len);
if (!property || len != sizeof(int)) {
dev_err(&client->dev, "invalid reg on %s\n",
node->full_name);
continue;
}
channel = be32_to_cpup(property);
if (channel > ADS1015_CHANNELS) {
dev_err(&client->dev,
"invalid channel index %d on %s\n",
channel, node->full_name);
continue;
}
property = of_get_property(node, "ti,gain", &len);
if (property && len == sizeof(int)) {
pga = be32_to_cpup(property);
if (pga > 6) {
dev_err(&client->dev,
"invalid gain on %s\n",
node->full_name);
}
}
property = of_get_property(node, "ti,datarate", &len);
if (property && len == sizeof(int)) {
data_rate = be32_to_cpup(property);
if (data_rate > 7) {
dev_err(&client->dev,
"invalid data_rate on %s\n",
node->full_name);
}
}
data->channel_data[channel].enabled = true;
data->channel_data[channel].pga = pga;
data->channel_data[channel].data_rate = data_rate;
}
return 0;
}
#endif
static void ads1015_get_channels_config(struct i2c_client *client)
{
unsigned int k;
struct ads1015_data *data = i2c_get_clientdata(client);
struct ads1015_platform_data *pdata = dev_get_platdata(&client->dev);
/* prefer platform data */
if (pdata) {
memcpy(data->channel_data, pdata->channel_data,
sizeof(data->channel_data));
return;
}
#ifdef CONFIG_OF
if (!ads1015_get_channels_config_of(client))
return;
#endif
/* fallback on default configuration */
for (k = 0; k < ADS1015_CHANNELS; ++k) {
data->channel_data[k].enabled = true;
data->channel_data[k].pga = ADS1015_DEFAULT_PGA;
data->channel_data[k].data_rate = ADS1015_DEFAULT_DATA_RATE;
}
}
static int ads1015_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct ads1015_data *data;
int err;
unsigned int k;
data = kzalloc(sizeof(struct ads1015_data), GFP_KERNEL);
if (!data) {
err = -ENOMEM;
goto exit;
}
i2c_set_clientdata(client, data);
mutex_init(&data->update_lock);
/* build sysfs attribute group */
ads1015_get_channels_config(client);
for (k = 0; k < ADS1015_CHANNELS; ++k) {
if (!data->channel_data[k].enabled)
continue;
err = device_create_file(&client->dev, &ads1015_in[k].dev_attr);
if (err)
goto exit_remove;
}
data->hwmon_dev = hwmon_device_register(&client->dev);
if (IS_ERR(data->hwmon_dev)) {
err = PTR_ERR(data->hwmon_dev);
goto exit_remove;
}
return 0;
exit_remove:
for (k = 0; k < ADS1015_CHANNELS; ++k)
device_remove_file(&client->dev, &ads1015_in[k].dev_attr);
kfree(data);
exit:
return err;
}
static const struct i2c_device_id ads1015_id[] = {
{ "ads1015", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, ads1015_id);
static struct i2c_driver ads1015_driver = {
.driver = {
.name = "ads1015",
},
.probe = ads1015_probe,
.remove = ads1015_remove,
.id_table = ads1015_id,
};
static int __init sensors_ads1015_init(void)
{
return i2c_add_driver(&ads1015_driver);
}
static void __exit sensors_ads1015_exit(void)
{
i2c_del_driver(&ads1015_driver);
}
MODULE_AUTHOR("Dirk Eibach <eibach@gdsys.de>");
MODULE_DESCRIPTION("ADS1015 driver");
MODULE_LICENSE("GPL");
module_init(sensors_ads1015_init);
module_exit(sensors_ads1015_exit);