https://jxself.org/git/linux-libre.git
Tip revision: b03b2359db615a2e1684b7866eebabf8f24fc7ba authored by Jason Self on 08 December 2013, 16:19:03 UTC
Linux-libre 3.12.4-gnu
Linux-libre 3.12.4-gnu
Tip revision: b03b235
ina209.c
/*
* Driver for the Texas Instruments / Burr Brown INA209
* Bidirectional Current/Power Monitor
*
* Copyright (C) 2012 Guenter Roeck <linux@roeck-us.net>
*
* Derived from Ira W. Snyder's original driver submission
* Copyright (C) 2008 Paul Hays <Paul.Hays@cattail.ca>
* Copyright (C) 2008-2009 Ira W. Snyder <iws@ovro.caltech.edu>
*
* Aligned with ina2xx driver
* Copyright (C) 2012 Lothar Felten <l-felten@ti.com>
* Thanks to Jan Volkering
*
* 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; version 2 of the License.
*
* Datasheet:
* http://www.ti.com/lit/gpn/ina209
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/bug.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/platform_data/ina2xx.h>
/* register definitions */
#define INA209_CONFIGURATION 0x00
#define INA209_STATUS 0x01
#define INA209_STATUS_MASK 0x02
#define INA209_SHUNT_VOLTAGE 0x03
#define INA209_BUS_VOLTAGE 0x04
#define INA209_POWER 0x05
#define INA209_CURRENT 0x06
#define INA209_SHUNT_VOLTAGE_POS_PEAK 0x07
#define INA209_SHUNT_VOLTAGE_NEG_PEAK 0x08
#define INA209_BUS_VOLTAGE_MAX_PEAK 0x09
#define INA209_BUS_VOLTAGE_MIN_PEAK 0x0a
#define INA209_POWER_PEAK 0x0b
#define INA209_SHUNT_VOLTAGE_POS_WARN 0x0c
#define INA209_SHUNT_VOLTAGE_NEG_WARN 0x0d
#define INA209_POWER_WARN 0x0e
#define INA209_BUS_VOLTAGE_OVER_WARN 0x0f
#define INA209_BUS_VOLTAGE_UNDER_WARN 0x10
#define INA209_POWER_OVER_LIMIT 0x11
#define INA209_BUS_VOLTAGE_OVER_LIMIT 0x12
#define INA209_BUS_VOLTAGE_UNDER_LIMIT 0x13
#define INA209_CRITICAL_DAC_POS 0x14
#define INA209_CRITICAL_DAC_NEG 0x15
#define INA209_CALIBRATION 0x16
#define INA209_REGISTERS 0x17
#define INA209_CONFIG_DEFAULT 0x3c47 /* PGA=8, full range */
#define INA209_SHUNT_DEFAULT 10000 /* uOhm */
struct ina209_data {
struct device *hwmon_dev;
struct mutex update_lock;
bool valid;
unsigned long last_updated; /* in jiffies */
u16 regs[INA209_REGISTERS]; /* All chip registers */
u16 config_orig; /* Original configuration */
u16 calibration_orig; /* Original calibration */
u16 update_interval;
};
static struct ina209_data *ina209_update_device(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct ina209_data *data = i2c_get_clientdata(client);
struct ina209_data *ret = data;
s32 val;
int i;
mutex_lock(&data->update_lock);
if (!data->valid ||
time_after(jiffies, data->last_updated + data->update_interval)) {
for (i = 0; i < ARRAY_SIZE(data->regs); i++) {
val = i2c_smbus_read_word_swapped(client, i);
if (val < 0) {
ret = ERR_PTR(val);
goto abort;
}
data->regs[i] = val;
}
data->last_updated = jiffies;
data->valid = true;
}
abort:
mutex_unlock(&data->update_lock);
return ret;
}
/*
* Read a value from a device register and convert it to the
* appropriate sysfs units
*/
static long ina209_from_reg(const u8 reg, const u16 val)
{
switch (reg) {
case INA209_SHUNT_VOLTAGE:
case INA209_SHUNT_VOLTAGE_POS_PEAK:
case INA209_SHUNT_VOLTAGE_NEG_PEAK:
case INA209_SHUNT_VOLTAGE_POS_WARN:
case INA209_SHUNT_VOLTAGE_NEG_WARN:
/* LSB=10 uV. Convert to mV. */
return DIV_ROUND_CLOSEST(val, 100);
case INA209_BUS_VOLTAGE:
case INA209_BUS_VOLTAGE_MAX_PEAK:
case INA209_BUS_VOLTAGE_MIN_PEAK:
case INA209_BUS_VOLTAGE_OVER_WARN:
case INA209_BUS_VOLTAGE_UNDER_WARN:
case INA209_BUS_VOLTAGE_OVER_LIMIT:
case INA209_BUS_VOLTAGE_UNDER_LIMIT:
/* LSB=4 mV, last 3 bits unused */
return (val >> 3) * 4;
case INA209_CRITICAL_DAC_POS:
/* LSB=1 mV, in the upper 8 bits */
return val >> 8;
case INA209_CRITICAL_DAC_NEG:
/* LSB=1 mV, in the upper 8 bits */
return -1 * (val >> 8);
case INA209_POWER:
case INA209_POWER_PEAK:
case INA209_POWER_WARN:
case INA209_POWER_OVER_LIMIT:
/* LSB=20 mW. Convert to uW */
return val * 20 * 1000L;
case INA209_CURRENT:
/* LSB=1 mA (selected). Is in mA */
return val;
}
/* programmer goofed */
WARN_ON_ONCE(1);
return 0;
}
/*
* Take a value and convert it to register format, clamping the value
* to the appropriate range.
*/
static int ina209_to_reg(u8 reg, u16 old, long val)
{
switch (reg) {
case INA209_SHUNT_VOLTAGE_POS_WARN:
case INA209_SHUNT_VOLTAGE_NEG_WARN:
/* Limit to +- 320 mV, 10 uV LSB */
return clamp_val(val, -320, 320) * 100;
case INA209_BUS_VOLTAGE_OVER_WARN:
case INA209_BUS_VOLTAGE_UNDER_WARN:
case INA209_BUS_VOLTAGE_OVER_LIMIT:
case INA209_BUS_VOLTAGE_UNDER_LIMIT:
/*
* Limit to 0-32000 mV, 4 mV LSB
*
* The last three bits aren't part of the value, but we'll
* preserve them in their original state.
*/
return (DIV_ROUND_CLOSEST(clamp_val(val, 0, 32000), 4) << 3)
| (old & 0x7);
case INA209_CRITICAL_DAC_NEG:
/*
* Limit to -255-0 mV, 1 mV LSB
* Convert the value to a positive value for the register
*
* The value lives in the top 8 bits only, be careful
* and keep original value of other bits.
*/
return (clamp_val(-val, 0, 255) << 8) | (old & 0xff);
case INA209_CRITICAL_DAC_POS:
/*
* Limit to 0-255 mV, 1 mV LSB
*
* The value lives in the top 8 bits only, be careful
* and keep original value of other bits.
*/
return (clamp_val(val, 0, 255) << 8) | (old & 0xff);
case INA209_POWER_WARN:
case INA209_POWER_OVER_LIMIT:
/* 20 mW LSB */
return DIV_ROUND_CLOSEST(val, 20 * 1000);
}
/* Other registers are read-only, return access error */
return -EACCES;
}
static int ina209_interval_from_reg(u16 reg)
{
return 68 >> (15 - ((reg >> 3) & 0x0f));
}
static u16 ina209_reg_from_interval(u16 config, long interval)
{
int i, adc;
if (interval <= 0) {
adc = 8;
} else {
adc = 15;
for (i = 34 + 34 / 2; i; i >>= 1) {
if (i < interval)
break;
adc--;
}
}
return (config & 0xf807) | (adc << 3) | (adc << 7);
}
static ssize_t ina209_set_interval(struct device *dev,
struct device_attribute *da,
const char *buf, size_t count)
{
struct i2c_client *client = to_i2c_client(dev);
struct ina209_data *data = ina209_update_device(dev);
long val;
u16 regval;
int ret;
if (IS_ERR(data))
return PTR_ERR(data);
ret = kstrtol(buf, 10, &val);
if (ret < 0)
return ret;
mutex_lock(&data->update_lock);
regval = ina209_reg_from_interval(data->regs[INA209_CONFIGURATION],
val);
i2c_smbus_write_word_swapped(client, INA209_CONFIGURATION, regval);
data->regs[INA209_CONFIGURATION] = regval;
data->update_interval = ina209_interval_from_reg(regval);
mutex_unlock(&data->update_lock);
return count;
}
static ssize_t ina209_show_interval(struct device *dev,
struct device_attribute *da, char *buf)
{
struct i2c_client *client = to_i2c_client(dev);
struct ina209_data *data = i2c_get_clientdata(client);
return snprintf(buf, PAGE_SIZE, "%d\n", data->update_interval);
}
/*
* History is reset by writing 1 into bit 0 of the respective peak register.
* Since more than one peak register may be affected by the scope of a
* reset_history attribute write, use a bit mask in attr->index to identify
* which registers are affected.
*/
static u16 ina209_reset_history_regs[] = {
INA209_SHUNT_VOLTAGE_POS_PEAK,
INA209_SHUNT_VOLTAGE_NEG_PEAK,
INA209_BUS_VOLTAGE_MAX_PEAK,
INA209_BUS_VOLTAGE_MIN_PEAK,
INA209_POWER_PEAK
};
static ssize_t ina209_reset_history(struct device *dev,
struct device_attribute *da,
const char *buf,
size_t count)
{
struct i2c_client *client = to_i2c_client(dev);
struct ina209_data *data = i2c_get_clientdata(client);
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
u32 mask = attr->index;
long val;
int i, ret;
ret = kstrtol(buf, 10, &val);
if (ret < 0)
return ret;
mutex_lock(&data->update_lock);
for (i = 0; i < ARRAY_SIZE(ina209_reset_history_regs); i++) {
if (mask & (1 << i))
i2c_smbus_write_word_swapped(client,
ina209_reset_history_regs[i], 1);
}
data->valid = false;
mutex_unlock(&data->update_lock);
return count;
}
static ssize_t ina209_set_value(struct device *dev,
struct device_attribute *da,
const char *buf,
size_t count)
{
struct i2c_client *client = to_i2c_client(dev);
struct ina209_data *data = ina209_update_device(dev);
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
int reg = attr->index;
long val;
int ret;
if (IS_ERR(data))
return PTR_ERR(data);
ret = kstrtol(buf, 10, &val);
if (ret < 0)
return ret;
mutex_lock(&data->update_lock);
ret = ina209_to_reg(reg, data->regs[reg], val);
if (ret < 0) {
count = ret;
goto abort;
}
i2c_smbus_write_word_swapped(client, reg, ret);
data->regs[reg] = ret;
abort:
mutex_unlock(&data->update_lock);
return count;
}
static ssize_t ina209_show_value(struct device *dev,
struct device_attribute *da,
char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
struct ina209_data *data = ina209_update_device(dev);
long val;
if (IS_ERR(data))
return PTR_ERR(data);
val = ina209_from_reg(attr->index, data->regs[attr->index]);
return snprintf(buf, PAGE_SIZE, "%ld\n", val);
}
static ssize_t ina209_show_alarm(struct device *dev,
struct device_attribute *da,
char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
struct ina209_data *data = ina209_update_device(dev);
const unsigned int mask = attr->index;
u16 status;
if (IS_ERR(data))
return PTR_ERR(data);
status = data->regs[INA209_STATUS];
/*
* All alarms are in the INA209_STATUS register. To avoid a long
* switch statement, the mask is passed in attr->index
*/
return snprintf(buf, PAGE_SIZE, "%u\n", !!(status & mask));
}
/* Shunt voltage, history, limits, alarms */
static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, ina209_show_value, NULL,
INA209_SHUNT_VOLTAGE);
static SENSOR_DEVICE_ATTR(in0_input_highest, S_IRUGO, ina209_show_value, NULL,
INA209_SHUNT_VOLTAGE_POS_PEAK);
static SENSOR_DEVICE_ATTR(in0_input_lowest, S_IRUGO, ina209_show_value, NULL,
INA209_SHUNT_VOLTAGE_NEG_PEAK);
static SENSOR_DEVICE_ATTR(in0_reset_history, S_IWUSR, NULL,
ina209_reset_history, (1 << 0) | (1 << 1));
static SENSOR_DEVICE_ATTR(in0_max, S_IRUGO | S_IWUSR, ina209_show_value,
ina209_set_value, INA209_SHUNT_VOLTAGE_POS_WARN);
static SENSOR_DEVICE_ATTR(in0_min, S_IRUGO | S_IWUSR, ina209_show_value,
ina209_set_value, INA209_SHUNT_VOLTAGE_NEG_WARN);
static SENSOR_DEVICE_ATTR(in0_crit_max, S_IRUGO | S_IWUSR, ina209_show_value,
ina209_set_value, INA209_CRITICAL_DAC_POS);
static SENSOR_DEVICE_ATTR(in0_crit_min, S_IRUGO | S_IWUSR, ina209_show_value,
ina209_set_value, INA209_CRITICAL_DAC_NEG);
static SENSOR_DEVICE_ATTR(in0_min_alarm, S_IRUGO, ina209_show_alarm, NULL,
1 << 11);
static SENSOR_DEVICE_ATTR(in0_max_alarm, S_IRUGO, ina209_show_alarm, NULL,
1 << 12);
static SENSOR_DEVICE_ATTR(in0_crit_min_alarm, S_IRUGO, ina209_show_alarm, NULL,
1 << 6);
static SENSOR_DEVICE_ATTR(in0_crit_max_alarm, S_IRUGO, ina209_show_alarm, NULL,
1 << 7);
/* Bus voltage, history, limits, alarms */
static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, ina209_show_value, NULL,
INA209_BUS_VOLTAGE);
static SENSOR_DEVICE_ATTR(in1_input_highest, S_IRUGO, ina209_show_value, NULL,
INA209_BUS_VOLTAGE_MAX_PEAK);
static SENSOR_DEVICE_ATTR(in1_input_lowest, S_IRUGO, ina209_show_value, NULL,
INA209_BUS_VOLTAGE_MIN_PEAK);
static SENSOR_DEVICE_ATTR(in1_reset_history, S_IWUSR, NULL,
ina209_reset_history, (1 << 2) | (1 << 3));
static SENSOR_DEVICE_ATTR(in1_max, S_IRUGO | S_IWUSR, ina209_show_value,
ina209_set_value, INA209_BUS_VOLTAGE_OVER_WARN);
static SENSOR_DEVICE_ATTR(in1_min, S_IRUGO | S_IWUSR, ina209_show_value,
ina209_set_value, INA209_BUS_VOLTAGE_UNDER_WARN);
static SENSOR_DEVICE_ATTR(in1_crit_max, S_IRUGO | S_IWUSR, ina209_show_value,
ina209_set_value, INA209_BUS_VOLTAGE_OVER_LIMIT);
static SENSOR_DEVICE_ATTR(in1_crit_min, S_IRUGO | S_IWUSR, ina209_show_value,
ina209_set_value, INA209_BUS_VOLTAGE_UNDER_LIMIT);
static SENSOR_DEVICE_ATTR(in1_min_alarm, S_IRUGO, ina209_show_alarm, NULL,
1 << 14);
static SENSOR_DEVICE_ATTR(in1_max_alarm, S_IRUGO, ina209_show_alarm, NULL,
1 << 15);
static SENSOR_DEVICE_ATTR(in1_crit_min_alarm, S_IRUGO, ina209_show_alarm, NULL,
1 << 9);
static SENSOR_DEVICE_ATTR(in1_crit_max_alarm, S_IRUGO, ina209_show_alarm, NULL,
1 << 10);
/* Power */
static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, ina209_show_value, NULL,
INA209_POWER);
static SENSOR_DEVICE_ATTR(power1_input_highest, S_IRUGO, ina209_show_value,
NULL, INA209_POWER_PEAK);
static SENSOR_DEVICE_ATTR(power1_reset_history, S_IWUSR, NULL,
ina209_reset_history, 1 << 4);
static SENSOR_DEVICE_ATTR(power1_max, S_IRUGO | S_IWUSR, ina209_show_value,
ina209_set_value, INA209_POWER_WARN);
static SENSOR_DEVICE_ATTR(power1_crit, S_IRUGO | S_IWUSR, ina209_show_value,
ina209_set_value, INA209_POWER_OVER_LIMIT);
static SENSOR_DEVICE_ATTR(power1_max_alarm, S_IRUGO, ina209_show_alarm, NULL,
1 << 13);
static SENSOR_DEVICE_ATTR(power1_crit_alarm, S_IRUGO, ina209_show_alarm, NULL,
1 << 8);
/* Current */
static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, ina209_show_value, NULL,
INA209_CURRENT);
static SENSOR_DEVICE_ATTR(update_interval, S_IRUGO | S_IWUSR,
ina209_show_interval, ina209_set_interval, 0);
/*
* Finally, construct an array of pointers to members of the above objects,
* as required for sysfs_create_group()
*/
static struct attribute *ina209_attributes[] = {
&sensor_dev_attr_in0_input.dev_attr.attr,
&sensor_dev_attr_in0_input_highest.dev_attr.attr,
&sensor_dev_attr_in0_input_lowest.dev_attr.attr,
&sensor_dev_attr_in0_reset_history.dev_attr.attr,
&sensor_dev_attr_in0_max.dev_attr.attr,
&sensor_dev_attr_in0_min.dev_attr.attr,
&sensor_dev_attr_in0_crit_max.dev_attr.attr,
&sensor_dev_attr_in0_crit_min.dev_attr.attr,
&sensor_dev_attr_in0_max_alarm.dev_attr.attr,
&sensor_dev_attr_in0_min_alarm.dev_attr.attr,
&sensor_dev_attr_in0_crit_max_alarm.dev_attr.attr,
&sensor_dev_attr_in0_crit_min_alarm.dev_attr.attr,
&sensor_dev_attr_in1_input.dev_attr.attr,
&sensor_dev_attr_in1_input_highest.dev_attr.attr,
&sensor_dev_attr_in1_input_lowest.dev_attr.attr,
&sensor_dev_attr_in1_reset_history.dev_attr.attr,
&sensor_dev_attr_in1_max.dev_attr.attr,
&sensor_dev_attr_in1_min.dev_attr.attr,
&sensor_dev_attr_in1_crit_max.dev_attr.attr,
&sensor_dev_attr_in1_crit_min.dev_attr.attr,
&sensor_dev_attr_in1_max_alarm.dev_attr.attr,
&sensor_dev_attr_in1_min_alarm.dev_attr.attr,
&sensor_dev_attr_in1_crit_max_alarm.dev_attr.attr,
&sensor_dev_attr_in1_crit_min_alarm.dev_attr.attr,
&sensor_dev_attr_power1_input.dev_attr.attr,
&sensor_dev_attr_power1_input_highest.dev_attr.attr,
&sensor_dev_attr_power1_reset_history.dev_attr.attr,
&sensor_dev_attr_power1_max.dev_attr.attr,
&sensor_dev_attr_power1_crit.dev_attr.attr,
&sensor_dev_attr_power1_max_alarm.dev_attr.attr,
&sensor_dev_attr_power1_crit_alarm.dev_attr.attr,
&sensor_dev_attr_curr1_input.dev_attr.attr,
&sensor_dev_attr_update_interval.dev_attr.attr,
NULL,
};
static const struct attribute_group ina209_group = {
.attrs = ina209_attributes,
};
static void ina209_restore_conf(struct i2c_client *client,
struct ina209_data *data)
{
/* Restore initial configuration */
i2c_smbus_write_word_swapped(client, INA209_CONFIGURATION,
data->config_orig);
i2c_smbus_write_word_swapped(client, INA209_CALIBRATION,
data->calibration_orig);
}
static int ina209_init_client(struct i2c_client *client,
struct ina209_data *data)
{
struct ina2xx_platform_data *pdata = dev_get_platdata(&client->dev);
u32 shunt;
int reg;
reg = i2c_smbus_read_word_swapped(client, INA209_CALIBRATION);
if (reg < 0)
return reg;
data->calibration_orig = reg;
reg = i2c_smbus_read_word_swapped(client, INA209_CONFIGURATION);
if (reg < 0)
return reg;
data->config_orig = reg;
if (pdata) {
if (pdata->shunt_uohms <= 0)
return -EINVAL;
shunt = pdata->shunt_uohms;
} else if (!of_property_read_u32(client->dev.of_node, "shunt-resistor",
&shunt)) {
if (shunt == 0)
return -EINVAL;
} else {
shunt = data->calibration_orig ?
40960000 / data->calibration_orig : INA209_SHUNT_DEFAULT;
}
i2c_smbus_write_word_swapped(client, INA209_CONFIGURATION,
INA209_CONFIG_DEFAULT);
data->update_interval = ina209_interval_from_reg(INA209_CONFIG_DEFAULT);
/*
* Calibrate current LSB to 1mA. Shunt is in uOhms.
* See equation 13 in datasheet.
*/
i2c_smbus_write_word_swapped(client, INA209_CALIBRATION,
clamp_val(40960000 / shunt, 1, 65535));
/* Clear status register */
i2c_smbus_read_word_swapped(client, INA209_STATUS);
return 0;
}
static int ina209_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct i2c_adapter *adapter = client->adapter;
struct ina209_data *data;
int ret;
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA))
return -ENODEV;
data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
i2c_set_clientdata(client, data);
mutex_init(&data->update_lock);
ret = ina209_init_client(client, data);
if (ret)
return ret;
/* Register sysfs hooks */
ret = sysfs_create_group(&client->dev.kobj, &ina209_group);
if (ret)
goto out_restore_conf;
data->hwmon_dev = hwmon_device_register(&client->dev);
if (IS_ERR(data->hwmon_dev)) {
ret = PTR_ERR(data->hwmon_dev);
goto out_hwmon_device_register;
}
return 0;
out_hwmon_device_register:
sysfs_remove_group(&client->dev.kobj, &ina209_group);
out_restore_conf:
ina209_restore_conf(client, data);
return ret;
}
static int ina209_remove(struct i2c_client *client)
{
struct ina209_data *data = i2c_get_clientdata(client);
hwmon_device_unregister(data->hwmon_dev);
sysfs_remove_group(&client->dev.kobj, &ina209_group);
ina209_restore_conf(client, data);
return 0;
}
static const struct i2c_device_id ina209_id[] = {
{ "ina209", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, ina209_id);
/* This is the driver that will be inserted */
static struct i2c_driver ina209_driver = {
.class = I2C_CLASS_HWMON,
.driver = {
.name = "ina209",
},
.probe = ina209_probe,
.remove = ina209_remove,
.id_table = ina209_id,
};
module_i2c_driver(ina209_driver);
MODULE_AUTHOR("Ira W. Snyder <iws@ovro.caltech.edu>, Paul Hays <Paul.Hays@cattail.ca>, Guenter Roeck <linux@roeck-us.net>");
MODULE_DESCRIPTION("INA209 driver");
MODULE_LICENSE("GPL");