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hwmon: (tmp102) Various fixes
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Fixes from my driver review:
http://lists.lm-sensors.org/pipermail/lm-sensors/2010-March/028051.html

Only the small changes are in there, more important changes will come
later separately as time permits.

* Drop the remnants of the now gone detect function
* The TMP102 has no known compatible chip
* Include the right header files
* Clarify why byte swapping of register values is needed
* Strip resolution info bit from temperature register value
* Set cache lifetime to 1/3 second
* Don't arbitrarily reject limit values; clamp as needed
* Make limit writing unconditional
* Don't check for transaction types the driver doesn't use
* Properly check for error when setting configuration
* Report error on failed probe
* Make the driver load automatically where needed
* Various other minor fixes

Signed-off-by: Jean Delvare <[email protected]>
Cc: Steven King <[email protected]>
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Jean Delvare committed May 27, 2010
1 parent beb1b6b commit cff37c9
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Showing 3 changed files with 39 additions and 42 deletions.
9 changes: 4 additions & 5 deletions Documentation/hwmon/tmp102
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Original file line number Diff line number Diff line change
Expand Up @@ -4,7 +4,7 @@ Kernel driver tmp102
Supported chips:
* Texas Instruments TMP102
Prefix: 'tmp102'
Addresses scanned: I2C 0x48 0x49 0x4a 0x4b
Addresses scanned: none
Datasheet: http://focus.ti.com/docs/prod/folders/print/tmp102.html

Author:
Expand All @@ -15,13 +15,12 @@ Description

The Texas Instruments TMP102 implements one temperature sensor. Limits can be
set through the Overtemperature Shutdown register and Hysteresis register. The
sensor is accurate to 0.5 degrees over the range of -25 to +85 C, and to 1.0
degrees from -40 to +125 C. Resolution of the sensor is 0.0625 degree. The
sensor is accurate to 0.5 degree over the range of -25 to +85 C, and to 1.0
degree from -40 to +125 C. Resolution of the sensor is 0.0625 degree. The
operating temperature has a minimum of -55 C and a maximum of +150 C.

The TMP102 has a programmable update rate that can select between 8, 4, 1, and
0.5 Hz. (Currently the driver only supports the default of 4 Hz).

The driver provides the common sysfs-interface for temperatures (see
/Documentation/hwmon/sysfs-interface under Temperatures).

Documentation/hwmon/sysfs-interface under Temperatures).
2 changes: 1 addition & 1 deletion drivers/hwmon/Kconfig
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Original file line number Diff line number Diff line change
Expand Up @@ -843,7 +843,7 @@ config SENSORS_THMC50
will be called thmc50.

config SENSORS_TMP102
tristate "Texas Instruments TMP102 and compatibles"
tristate "Texas Instruments TMP102"
depends on I2C && EXPERIMENTAL
help
If you say yes here you get support for Texas Instruments TMP102
Expand Down
70 changes: 34 additions & 36 deletions drivers/hwmon/tmp102.c
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Original file line number Diff line number Diff line change
@@ -1,6 +1,6 @@
/* Texas Instruments TMP102 SMBUS temperature sensor driver
/* Texas Instruments TMP102 SMBus temperature sensor driver
*
* Copyright 2010 Steven King <[email protected]>
* Copyright (C) 2010 Steven King <[email protected]>
*
* 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
Expand All @@ -17,8 +17,6 @@
* Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA
*/



#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
Expand All @@ -27,7 +25,7 @@
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include <linux/device.h>

#define DRIVER_NAME "tmp102"

Expand Down Expand Up @@ -56,26 +54,27 @@ struct tmp102 {
int temp[3];
};

/* the TMP102 registers are big endian so we have to swab16 the values */
static int tmp102_read_reg(struct i2c_client *client, u8 reg)
/* SMBus specifies low byte first, but the TMP102 returns high byte first,
* so we have to swab16 the values */
static inline int tmp102_read_reg(struct i2c_client *client, u8 reg)
{
int result = i2c_smbus_read_word_data(client, reg);
return result < 0 ? result : swab16(result);
}

static int tmp102_write_reg(struct i2c_client *client, u8 reg, u16 val)
static inline int tmp102_write_reg(struct i2c_client *client, u8 reg, u16 val)
{
return i2c_smbus_write_word_data(client, reg, swab16(val));
}

/* convert left adjusted 13bit TMP102 register value to miliCelsius */
static int tmp102_reg_to_mC(s16 val)
/* convert left adjusted 13-bit TMP102 register value to milliCelsius */
static inline int tmp102_reg_to_mC(s16 val)
{
return (val * 1000) / 128;
return ((val & ~0x01) * 1000) / 128;
}

/* convert miliCelsius to left adjusted 13bit TMP102 register value */
static u16 tmp102_mC_to_reg(int val)
/* convert milliCelsius to left adjusted 13-bit TMP102 register value */
static inline u16 tmp102_mC_to_reg(int val)
{
return (val * 128) / 1000;
}
Expand All @@ -91,7 +90,7 @@ static struct tmp102 *tmp102_update_device(struct i2c_client *client)
struct tmp102 *tmp102 = i2c_get_clientdata(client);

mutex_lock(&tmp102->lock);
if (time_after(jiffies, tmp102->last_update + HZ / 4)) {
if (time_after(jiffies, tmp102->last_update + HZ / 3)) {
int i;
for (i = 0; i < ARRAY_SIZE(tmp102->temp); ++i) {
int status = tmp102_read_reg(client, tmp102_reg[i]);
Expand Down Expand Up @@ -122,16 +121,16 @@ static ssize_t tmp102_set_temp(struct device *dev,
struct i2c_client *client = to_i2c_client(dev);
struct tmp102 *tmp102 = i2c_get_clientdata(client);
long val;
int status = 0;
int status;

if ((strict_strtol(buf, 10, &val) < 0) || (abs(val) > 150000))
if (strict_strtol(buf, 10, &val) < 0)
return -EINVAL;
val = SENSORS_LIMIT(val, -256000, 255000);

mutex_lock(&tmp102->lock);
if (tmp102->temp[sda->index] != val) {
tmp102->temp[sda->index] = val;
status = tmp102_write_reg(client, tmp102_reg[sda->index],
tmp102_mC_to_reg(val));
}
tmp102->temp[sda->index] = val;
status = tmp102_write_reg(client, tmp102_reg[sda->index],
tmp102_mC_to_reg(val));
mutex_unlock(&tmp102->lock);
return status ? : count;
}
Expand Down Expand Up @@ -164,9 +163,10 @@ static int __devinit tmp102_probe(struct i2c_client *client,
struct tmp102 *tmp102;
int status;

if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA |
if (!i2c_check_functionality(client->adapter,
I2C_FUNC_SMBUS_WORD_DATA)) {
dev_dbg(&client->dev, "adapter doesnt support SMBUS\n");
dev_err(&client->dev, "adapter doesnt support SMBus word "
"transactions\n");
return -ENODEV;
}

Expand All @@ -177,16 +177,20 @@ static int __devinit tmp102_probe(struct i2c_client *client,
}
i2c_set_clientdata(client, tmp102);

tmp102_write_reg(client, TMP102_CONF_REG, TMP102_CONFIG);
status = tmp102_write_reg(client, TMP102_CONF_REG, TMP102_CONFIG);
if (status < 0) {
dev_err(&client->dev, "error writing config register\n");
goto fail0;
}
status = tmp102_read_reg(client, TMP102_CONF_REG);
if (status < 0) {
dev_dbg(&client->dev, "error reading config register\n");
dev_err(&client->dev, "error reading config register\n");
goto fail0;
}
status &= ~TMP102_CONFIG_RD_ONLY;
if (status != TMP102_CONFIG) {
dev_dbg(&client->dev, "could not verify config settings\n");
status = -EIO;
dev_err(&client->dev, "config settings did not stick\n");
status = -ENODEV;
goto fail0;
}
tmp102->last_update = jiffies - HZ;
Expand All @@ -213,7 +217,7 @@ static int __devinit tmp102_probe(struct i2c_client *client,
i2c_set_clientdata(client, NULL);
kfree(tmp102);

return 0;
return status;
}

static int __devexit tmp102_remove(struct i2c_client *client)
Expand Down Expand Up @@ -260,23 +264,18 @@ static const struct dev_pm_ops tmp102_dev_pm_ops = {
#define TMP102_DEV_PM_OPS NULL
#endif /* CONFIG_PM */

static const unsigned short normal_i2c[] = {
0x48, 0x49, 0x4a, 0x4b, I2C_CLIENT_END
};

static const struct i2c_device_id tmp102_id[] = {
{ DRIVER_NAME, 0 },
{ "tmp102", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, tmp102_id);

static struct i2c_driver tmp102_driver = {
.driver.name = DRIVER_NAME,
.driver.pm = TMP102_DEV_PM_OPS,
.class = I2C_CLASS_HWMON,
.probe = tmp102_probe,
.remove = __devexit_p(tmp102_remove),
.id_table = tmp102_id,
.address_list = normal_i2c,
};

static int __init tmp102_init(void)
Expand All @@ -291,7 +290,6 @@ static void __exit tmp102_exit(void)
}
module_exit(tmp102_exit);


MODULE_AUTHOR("Steven King <[email protected]>");
MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver");
MODULE_LICENSE("GPL");

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