hwmon: add Maxim MAX197 support
The MAX197 is an A/D converter, made by Maxim. This driver currently
supports the MAX197, and MAX199. They are both 8-Channel, Multi-Range,
5V, 12-Bit DAS with 8+4 Bus Interface and Fault Protection.
The available ranges for the MAX197 are {0,-5V} to 5V, and {0,-10V} to
10V, while they are {0,-2V} to 2V, and {0,-4V} to 4V on the MAX199.
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
This commit is contained in:
Vivien Didelot
Guenter Roeck
Родитель
37f9648b27
Коммит
6c1fe725fd
|
|
@ -0,0 +1,60 @@
|
|||
Maxim MAX197 driver
|
||||
===================
|
||||
|
||||
Author:
|
||||
* Vivien Didelot <vivien.didelot@savoirfairelinux.com>
|
||||
|
||||
Supported chips:
|
||||
* Maxim MAX197
|
||||
Prefix: 'max197'
|
||||
Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX197.pdf
|
||||
|
||||
* Maxim MAX199
|
||||
Prefix: 'max199'
|
||||
Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX199.pdf
|
||||
|
||||
Description
|
||||
-----------
|
||||
|
||||
The A/D converters MAX197, and MAX199 are both 8-Channel, Multi-Range, 5V,
|
||||
12-Bit DAS with 8+4 Bus Interface and Fault Protection.
|
||||
|
||||
The available ranges for the MAX197 are {0,-5V} to 5V, and {0,-10V} to 10V,
|
||||
while they are {0,-2V} to 2V, and {0,-4V} to 4V on the MAX199.
|
||||
|
||||
Platform data
|
||||
-------------
|
||||
|
||||
The MAX197 platform data (defined in linux/platform_data/max197.h) should be
|
||||
filled with a pointer to a conversion function, defined like:
|
||||
|
||||
int convert(u8 ctrl);
|
||||
|
||||
ctrl is the control byte to write to start a new conversion.
|
||||
On success, the function must return the 12-bit raw value read from the chip,
|
||||
or a negative error code otherwise.
|
||||
|
||||
Control byte format:
|
||||
|
||||
Bit Name Description
|
||||
7,6 PD1,PD0 Clock and Power-Down modes
|
||||
5 ACQMOD Internal or External Controlled Acquisition
|
||||
4 RNG Full-scale voltage magnitude at the input
|
||||
3 BIP Unipolar or Bipolar conversion mode
|
||||
2,1,0 A2,A1,A0 Channel
|
||||
|
||||
Sysfs interface
|
||||
---------------
|
||||
|
||||
* in[0-7]_input: The conversion value for the corresponding channel.
|
||||
RO
|
||||
|
||||
* in[0-7]_min: The lower limit (in mV) for the corresponding channel.
|
||||
For the MAX197, it will be adjusted to -10000, -5000, or 0.
|
||||
For the MAX199, it will be adjusted to -4000, -2000, or 0.
|
||||
RW
|
||||
|
||||
* in[0-7]_max: The higher limit (in mV) for the corresponding channel.
|
||||
For the MAX197, it will be adjusted to 0, 5000, or 10000.
|
||||
For the MAX199, it will be adjusted to 0, 2000, or 4000.
|
||||
RW
|
||||
|
|
@ -813,6 +813,15 @@ config SENSORS_MAX1668
|
|||
This driver can also be built as a module. If so, the module
|
||||
will be called max1668.
|
||||
|
||||
config SENSORS_MAX197
|
||||
tristate "Maxim MAX197 and compatibles"
|
||||
help
|
||||
Support for the Maxim MAX197 A/D converter.
|
||||
Support will include, but not be limited to, MAX197, and MAX199.
|
||||
|
||||
This driver can also be built as a module. If so, the module
|
||||
will be called max197.
|
||||
|
||||
config SENSORS_MAX6639
|
||||
tristate "Maxim MAX6639 sensor chip"
|
||||
depends on I2C && EXPERIMENTAL
|
||||
|
|
|
|||
|
|
@ -95,6 +95,7 @@ obj-$(CONFIG_SENSORS_MAX1111) += max1111.o
|
|||
obj-$(CONFIG_SENSORS_MAX16065) += max16065.o
|
||||
obj-$(CONFIG_SENSORS_MAX1619) += max1619.o
|
||||
obj-$(CONFIG_SENSORS_MAX1668) += max1668.o
|
||||
obj-$(CONFIG_SENSORS_MAX197) += max197.o
|
||||
obj-$(CONFIG_SENSORS_MAX6639) += max6639.o
|
||||
obj-$(CONFIG_SENSORS_MAX6642) += max6642.o
|
||||
obj-$(CONFIG_SENSORS_MAX6650) += max6650.o
|
||||
|
|
|
|||
|
|
@ -0,0 +1,349 @@
|
|||
/*
|
||||
* Maxim MAX197 A/D Converter driver
|
||||
*
|
||||
* Copyright (c) 2012 Savoir-faire Linux Inc.
|
||||
* Vivien Didelot <vivien.didelot@savoirfairelinux.com>
|
||||
*
|
||||
* 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.
|
||||
*
|
||||
* For further information, see the Documentation/hwmon/max197 file.
|
||||
*/
|
||||
|
||||
#include <linux/kernel.h>
|
||||
#include <linux/module.h>
|
||||
#include <linux/init.h>
|
||||
#include <linux/err.h>
|
||||
#include <linux/slab.h>
|
||||
#include <linux/mutex.h>
|
||||
#include <linux/device.h>
|
||||
#include <linux/sysfs.h>
|
||||
#include <linux/hwmon.h>
|
||||
#include <linux/hwmon-sysfs.h>
|
||||
#include <linux/platform_device.h>
|
||||
#include <linux/platform_data/max197.h>
|
||||
|
||||
#define MAX199_LIMIT 4000 /* 4V */
|
||||
#define MAX197_LIMIT 10000 /* 10V */
|
||||
|
||||
#define MAX197_NUM_CH 8 /* 8 Analog Input Channels */
|
||||
|
||||
/* Control byte format */
|
||||
#define MAX197_BIP (1 << 3) /* Bipolarity */
|
||||
#define MAX197_RNG (1 << 4) /* Full range */
|
||||
|
||||
#define MAX197_SCALE 12207 /* Scale coefficient for raw data */
|
||||
|
||||
/* List of supported chips */
|
||||
enum max197_chips { max197, max199 };
|
||||
|
||||
/**
|
||||
* struct max197_data - device instance specific data
|
||||
* @pdata: Platform data.
|
||||
* @hwmon_dev: The hwmon device.
|
||||
* @lock: Read/Write mutex.
|
||||
* @limit: Max range value (10V for MAX197, 4V for MAX199).
|
||||
* @scale: Need to scale.
|
||||
* @ctrl_bytes: Channels control byte.
|
||||
*/
|
||||
struct max197_data {
|
||||
struct max197_platform_data *pdata;
|
||||
struct device *hwmon_dev;
|
||||
struct mutex lock;
|
||||
int limit;
|
||||
bool scale;
|
||||
u8 ctrl_bytes[MAX197_NUM_CH];
|
||||
};
|
||||
|
||||
static inline void max197_set_unipolarity(struct max197_data *data, int channel)
|
||||
{
|
||||
data->ctrl_bytes[channel] &= ~MAX197_BIP;
|
||||
}
|
||||
|
||||
static inline void max197_set_bipolarity(struct max197_data *data, int channel)
|
||||
{
|
||||
data->ctrl_bytes[channel] |= MAX197_BIP;
|
||||
}
|
||||
|
||||
static inline void max197_set_half_range(struct max197_data *data, int channel)
|
||||
{
|
||||
data->ctrl_bytes[channel] &= ~MAX197_RNG;
|
||||
}
|
||||
|
||||
static inline void max197_set_full_range(struct max197_data *data, int channel)
|
||||
{
|
||||
data->ctrl_bytes[channel] |= MAX197_RNG;
|
||||
}
|
||||
|
||||
static inline bool max197_is_bipolar(struct max197_data *data, int channel)
|
||||
{
|
||||
return data->ctrl_bytes[channel] & MAX197_BIP;
|
||||
}
|
||||
|
||||
static inline bool max197_is_full_range(struct max197_data *data, int channel)
|
||||
{
|
||||
return data->ctrl_bytes[channel] & MAX197_RNG;
|
||||
}
|
||||
|
||||
/* Function called on read access on in{0,1,2,3,4,5,6,7}_{min,max} */
|
||||
static ssize_t max197_show_range(struct device *dev,
|
||||
struct device_attribute *devattr, char *buf)
|
||||
{
|
||||
struct max197_data *data = dev_get_drvdata(dev);
|
||||
struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
|
||||
int channel = attr->index;
|
||||
bool is_min = attr->nr;
|
||||
int range;
|
||||
|
||||
if (mutex_lock_interruptible(&data->lock))
|
||||
return -ERESTARTSYS;
|
||||
|
||||
range = max197_is_full_range(data, channel) ?
|
||||
data->limit : data->limit / 2;
|
||||
if (is_min) {
|
||||
if (max197_is_bipolar(data, channel))
|
||||
range = -range;
|
||||
else
|
||||
range = 0;
|
||||
}
|
||||
|
||||
mutex_unlock(&data->lock);
|
||||
|
||||
return sprintf(buf, "%d\n", range);
|
||||
}
|
||||
|
||||
/* Function called on write access on in{0,1,2,3,4,5,6,7}_{min,max} */
|
||||
static ssize_t max197_store_range(struct device *dev,
|
||||
struct device_attribute *devattr,
|
||||
const char *buf, size_t count)
|
||||
{
|
||||
struct max197_data *data = dev_get_drvdata(dev);
|
||||
struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
|
||||
int channel = attr->index;
|
||||
bool is_min = attr->nr;
|
||||
long value;
|
||||
int half = data->limit / 2;
|
||||
int full = data->limit;
|
||||
|
||||
if (kstrtol(buf, 10, &value))
|
||||
return -EINVAL;
|
||||
|
||||
if (is_min) {
|
||||
if (value <= -full)
|
||||
value = -full;
|
||||
else if (value < 0)
|
||||
value = -half;
|
||||
else
|
||||
value = 0;
|
||||
} else {
|
||||
if (value >= full)
|
||||
value = full;
|
||||
else
|
||||
value = half;
|
||||
}
|
||||
|
||||
if (mutex_lock_interruptible(&data->lock))
|
||||
return -ERESTARTSYS;
|
||||
|
||||
if (value == 0) {
|
||||
/* We can deduce only the polarity */
|
||||
max197_set_unipolarity(data, channel);
|
||||
} else if (value == -half) {
|
||||
max197_set_bipolarity(data, channel);
|
||||
max197_set_half_range(data, channel);
|
||||
} else if (value == -full) {
|
||||
max197_set_bipolarity(data, channel);
|
||||
max197_set_full_range(data, channel);
|
||||
} else if (value == half) {
|
||||
/* We can deduce only the range */
|
||||
max197_set_half_range(data, channel);
|
||||
} else if (value == full) {
|
||||
/* We can deduce only the range */
|
||||
max197_set_full_range(data, channel);
|
||||
}
|
||||
|
||||
mutex_unlock(&data->lock);
|
||||
|
||||
return count;
|
||||
}
|
||||
|
||||
/* Function called on read access on in{0,1,2,3,4,5,6,7}_input */
|
||||
static ssize_t max197_show_input(struct device *dev,
|
||||
struct device_attribute *devattr,
|
||||
char *buf)
|
||||
{
|
||||
struct max197_data *data = dev_get_drvdata(dev);
|
||||
struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
|
||||
int channel = attr->index;
|
||||
s32 value;
|
||||
int ret;
|
||||
|
||||
if (mutex_lock_interruptible(&data->lock))
|
||||
return -ERESTARTSYS;
|
||||
|
||||
ret = data->pdata->convert(data->ctrl_bytes[channel]);
|
||||
if (ret < 0) {
|
||||
dev_err(dev, "conversion failed\n");
|
||||
goto unlock;
|
||||
}
|
||||
value = ret;
|
||||
|
||||
/*
|
||||
* Coefficient to apply on raw value.
|
||||
* See Table 1. Full Scale and Zero Scale in the MAX197 datasheet.
|
||||
*/
|
||||
if (data->scale) {
|
||||
value *= MAX197_SCALE;
|
||||
if (max197_is_full_range(data, channel))
|
||||
value *= 2;
|
||||
value /= 10000;
|
||||
}
|
||||
|
||||
ret = sprintf(buf, "%d\n", value);
|
||||
|
||||
unlock:
|
||||
mutex_unlock(&data->lock);
|
||||
return ret;
|
||||
}
|
||||
|
||||
static ssize_t max197_show_name(struct device *dev,
|
||||
struct device_attribute *attr, char *buf)
|
||||
{
|
||||
struct platform_device *pdev = to_platform_device(dev);
|
||||
return sprintf(buf, "%s\n", pdev->name);
|
||||
}
|
||||
|
||||
#define MAX197_SENSOR_DEVICE_ATTR_CH(chan) \
|
||||
static SENSOR_DEVICE_ATTR(in##chan##_input, S_IRUGO, \
|
||||
max197_show_input, NULL, chan); \
|
||||
static SENSOR_DEVICE_ATTR_2(in##chan##_min, S_IRUGO | S_IWUSR, \
|
||||
max197_show_range, \
|
||||
max197_store_range, \
|
||||
true, chan); \
|
||||
static SENSOR_DEVICE_ATTR_2(in##chan##_max, S_IRUGO | S_IWUSR, \
|
||||
max197_show_range, \
|
||||
max197_store_range, \
|
||||
false, chan)
|
||||
|
||||
#define MAX197_SENSOR_DEV_ATTR_IN(chan) \
|
||||
&sensor_dev_attr_in##chan##_input.dev_attr.attr, \
|
||||
&sensor_dev_attr_in##chan##_max.dev_attr.attr, \
|
||||
&sensor_dev_attr_in##chan##_min.dev_attr.attr
|
||||
|
||||
static DEVICE_ATTR(name, S_IRUGO, max197_show_name, NULL);
|
||||
|
||||
MAX197_SENSOR_DEVICE_ATTR_CH(0);
|
||||
MAX197_SENSOR_DEVICE_ATTR_CH(1);
|
||||
MAX197_SENSOR_DEVICE_ATTR_CH(2);
|
||||
MAX197_SENSOR_DEVICE_ATTR_CH(3);
|
||||
MAX197_SENSOR_DEVICE_ATTR_CH(4);
|
||||
MAX197_SENSOR_DEVICE_ATTR_CH(5);
|
||||
MAX197_SENSOR_DEVICE_ATTR_CH(6);
|
||||
MAX197_SENSOR_DEVICE_ATTR_CH(7);
|
||||
|
||||
static const struct attribute_group max197_sysfs_group = {
|
||||
.attrs = (struct attribute *[]) {
|
||||
&dev_attr_name.attr,
|
||||
MAX197_SENSOR_DEV_ATTR_IN(0),
|
||||
MAX197_SENSOR_DEV_ATTR_IN(1),
|
||||
MAX197_SENSOR_DEV_ATTR_IN(2),
|
||||
MAX197_SENSOR_DEV_ATTR_IN(3),
|
||||
MAX197_SENSOR_DEV_ATTR_IN(4),
|
||||
MAX197_SENSOR_DEV_ATTR_IN(5),
|
||||
MAX197_SENSOR_DEV_ATTR_IN(6),
|
||||
MAX197_SENSOR_DEV_ATTR_IN(7),
|
||||
NULL
|
||||
},
|
||||
};
|
||||
|
||||
static int __devinit max197_probe(struct platform_device *pdev)
|
||||
{
|
||||
int ch, ret;
|
||||
struct max197_data *data;
|
||||
struct max197_platform_data *pdata = pdev->dev.platform_data;
|
||||
enum max197_chips chip = platform_get_device_id(pdev)->driver_data;
|
||||
|
||||
if (pdata == NULL) {
|
||||
dev_err(&pdev->dev, "no platform data supplied\n");
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
if (pdata->convert == NULL) {
|
||||
dev_err(&pdev->dev, "no convert function supplied\n");
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
data = devm_kzalloc(&pdev->dev, sizeof(struct max197_data), GFP_KERNEL);
|
||||
if (!data) {
|
||||
dev_err(&pdev->dev, "devm_kzalloc failed\n");
|
||||
return -ENOMEM;
|
||||
}
|
||||
|
||||
data->pdata = pdata;
|
||||
mutex_init(&data->lock);
|
||||
|
||||
if (chip == max197) {
|
||||
data->limit = MAX197_LIMIT;
|
||||
data->scale = true;
|
||||
} else {
|
||||
data->limit = MAX199_LIMIT;
|
||||
data->scale = false;
|
||||
}
|
||||
|
||||
for (ch = 0; ch < MAX197_NUM_CH; ch++)
|
||||
data->ctrl_bytes[ch] = (u8) ch;
|
||||
|
||||
platform_set_drvdata(pdev, data);
|
||||
|
||||
ret = sysfs_create_group(&pdev->dev.kobj, &max197_sysfs_group);
|
||||
if (ret) {
|
||||
dev_err(&pdev->dev, "sysfs create group failed\n");
|
||||
return ret;
|
||||
}
|
||||
|
||||
data->hwmon_dev = hwmon_device_register(&pdev->dev);
|
||||
if (IS_ERR(data->hwmon_dev)) {
|
||||
ret = PTR_ERR(data->hwmon_dev);
|
||||
dev_err(&pdev->dev, "hwmon device register failed\n");
|
||||
goto error;
|
||||
}
|
||||
|
||||
return 0;
|
||||
|
||||
error:
|
||||
sysfs_remove_group(&pdev->dev.kobj, &max197_sysfs_group);
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int __devexit max197_remove(struct platform_device *pdev)
|
||||
{
|
||||
struct max197_data *data = platform_get_drvdata(pdev);
|
||||
|
||||
hwmon_device_unregister(data->hwmon_dev);
|
||||
sysfs_remove_group(&pdev->dev.kobj, &max197_sysfs_group);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static struct platform_device_id max197_device_ids[] = {
|
||||
{ "max197", max197 },
|
||||
{ "max199", max199 },
|
||||
{ }
|
||||
};
|
||||
MODULE_DEVICE_TABLE(platform, max197_device_ids);
|
||||
|
||||
static struct platform_driver max197_driver = {
|
||||
.driver = {
|
||||
.name = "max197",
|
||||
.owner = THIS_MODULE,
|
||||
},
|
||||
.probe = max197_probe,
|
||||
.remove = __devexit_p(max197_remove),
|
||||
.id_table = max197_device_ids,
|
||||
};
|
||||
module_platform_driver(max197_driver);
|
||||
|
||||
MODULE_LICENSE("GPL");
|
||||
MODULE_AUTHOR("Savoir-faire Linux Inc. <kernel@savoirfairelinux.com>");
|
||||
MODULE_DESCRIPTION("Maxim MAX197 A/D Converter driver");
|
||||
|
|
@ -0,0 +1,21 @@
|
|||
/*
|
||||
* Maxim MAX197 A/D Converter Driver
|
||||
*
|
||||
* Copyright (c) 2012 Savoir-faire Linux Inc.
|
||||
* Vivien Didelot <vivien.didelot@savoirfairelinux.com>
|
||||
*
|
||||
* 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.
|
||||
*
|
||||
* For further information, see the Documentation/hwmon/max197 file.
|
||||
*/
|
||||
|
||||
/**
|
||||
* struct max197_platform_data - MAX197 connectivity info
|
||||
* @convert: Function used to start a conversion with control byte ctrl.
|
||||
* It must return the raw data, or a negative error code.
|
||||
*/
|
||||
struct max197_platform_data {
|
||||
int (*convert)(u8 ctrl);
|
||||
};
|
||||
Загрузка…
Ссылка в новой задаче