linux/drivers/hwmon/ina3221.c

672 lines
17 KiB
C

/*
* INA3221 Triple Current/Voltage Monitor
*
* Copyright (C) 2016 Texas Instruments Incorporated - http://www.ti.com/
* Andrew F. Davis <afd@ti.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.
*
* 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.
*/
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/regmap.h>
#define INA3221_DRIVER_NAME "ina3221"
#define INA3221_CONFIG 0x00
#define INA3221_SHUNT1 0x01
#define INA3221_BUS1 0x02
#define INA3221_SHUNT2 0x03
#define INA3221_BUS2 0x04
#define INA3221_SHUNT3 0x05
#define INA3221_BUS3 0x06
#define INA3221_CRIT1 0x07
#define INA3221_WARN1 0x08
#define INA3221_CRIT2 0x09
#define INA3221_WARN2 0x0a
#define INA3221_CRIT3 0x0b
#define INA3221_WARN3 0x0c
#define INA3221_MASK_ENABLE 0x0f
#define INA3221_CONFIG_MODE_MASK GENMASK(2, 0)
#define INA3221_CONFIG_MODE_POWERDOWN 0
#define INA3221_CONFIG_MODE_SHUNT BIT(0)
#define INA3221_CONFIG_MODE_BUS BIT(1)
#define INA3221_CONFIG_MODE_CONTINUOUS BIT(2)
#define INA3221_CONFIG_CHx_EN(x) BIT(14 - (x))
#define INA3221_RSHUNT_DEFAULT 10000
enum ina3221_fields {
/* Configuration */
F_RST,
/* Alert Flags */
F_WF3, F_WF2, F_WF1,
F_CF3, F_CF2, F_CF1,
/* sentinel */
F_MAX_FIELDS
};
static const struct reg_field ina3221_reg_fields[] = {
[F_RST] = REG_FIELD(INA3221_CONFIG, 15, 15),
[F_WF3] = REG_FIELD(INA3221_MASK_ENABLE, 3, 3),
[F_WF2] = REG_FIELD(INA3221_MASK_ENABLE, 4, 4),
[F_WF1] = REG_FIELD(INA3221_MASK_ENABLE, 5, 5),
[F_CF3] = REG_FIELD(INA3221_MASK_ENABLE, 7, 7),
[F_CF2] = REG_FIELD(INA3221_MASK_ENABLE, 8, 8),
[F_CF1] = REG_FIELD(INA3221_MASK_ENABLE, 9, 9),
};
enum ina3221_channels {
INA3221_CHANNEL1,
INA3221_CHANNEL2,
INA3221_CHANNEL3,
INA3221_NUM_CHANNELS
};
/**
* struct ina3221_input - channel input source specific information
* @label: label of channel input source
* @shunt_resistor: shunt resistor value of channel input source
* @disconnected: connection status of channel input source
*/
struct ina3221_input {
const char *label;
int shunt_resistor;
bool disconnected;
};
/**
* struct ina3221_data - device specific information
* @regmap: Register map of the device
* @fields: Register fields of the device
* @inputs: Array of channel input source specific structures
* @reg_config: Register value of INA3221_CONFIG
*/
struct ina3221_data {
struct regmap *regmap;
struct regmap_field *fields[F_MAX_FIELDS];
struct ina3221_input inputs[INA3221_NUM_CHANNELS];
u32 reg_config;
};
static inline bool ina3221_is_enabled(struct ina3221_data *ina, int channel)
{
return ina->reg_config & INA3221_CONFIG_CHx_EN(channel);
}
static int ina3221_read_value(struct ina3221_data *ina, unsigned int reg,
int *val)
{
unsigned int regval;
int ret;
ret = regmap_read(ina->regmap, reg, &regval);
if (ret)
return ret;
*val = sign_extend32(regval >> 3, 12);
return 0;
}
static const u8 ina3221_in_reg[] = {
INA3221_BUS1,
INA3221_BUS2,
INA3221_BUS3,
INA3221_SHUNT1,
INA3221_SHUNT2,
INA3221_SHUNT3,
};
static int ina3221_read_in(struct device *dev, u32 attr, int channel, long *val)
{
const bool is_shunt = channel > INA3221_CHANNEL3;
struct ina3221_data *ina = dev_get_drvdata(dev);
u8 reg = ina3221_in_reg[channel];
int regval, ret;
/* Translate shunt channel index to sensor channel index */
channel %= INA3221_NUM_CHANNELS;
switch (attr) {
case hwmon_in_input:
if (!ina3221_is_enabled(ina, channel))
return -ENODATA;
ret = ina3221_read_value(ina, reg, &regval);
if (ret)
return ret;
/*
* Scale of shunt voltage (uV): LSB is 40uV
* Scale of bus voltage (mV): LSB is 8mV
*/
*val = regval * (is_shunt ? 40 : 8);
return 0;
case hwmon_in_enable:
*val = ina3221_is_enabled(ina, channel);
return 0;
default:
return -EOPNOTSUPP;
}
}
static const u8 ina3221_curr_reg[][INA3221_NUM_CHANNELS] = {
[hwmon_curr_input] = { INA3221_SHUNT1, INA3221_SHUNT2, INA3221_SHUNT3 },
[hwmon_curr_max] = { INA3221_WARN1, INA3221_WARN2, INA3221_WARN3 },
[hwmon_curr_crit] = { INA3221_CRIT1, INA3221_CRIT2, INA3221_CRIT3 },
[hwmon_curr_max_alarm] = { F_WF1, F_WF2, F_WF3 },
[hwmon_curr_crit_alarm] = { F_CF1, F_CF2, F_CF3 },
};
static int ina3221_read_curr(struct device *dev, u32 attr,
int channel, long *val)
{
struct ina3221_data *ina = dev_get_drvdata(dev);
struct ina3221_input *input = &ina->inputs[channel];
int resistance_uo = input->shunt_resistor;
u8 reg = ina3221_curr_reg[attr][channel];
int regval, voltage_nv, ret;
switch (attr) {
case hwmon_curr_input:
if (!ina3221_is_enabled(ina, channel))
return -ENODATA;
/* fall through */
case hwmon_curr_crit:
case hwmon_curr_max:
ret = ina3221_read_value(ina, reg, &regval);
if (ret)
return ret;
/* Scale of shunt voltage: LSB is 40uV (40000nV) */
voltage_nv = regval * 40000;
/* Return current in mA */
*val = DIV_ROUND_CLOSEST(voltage_nv, resistance_uo);
return 0;
case hwmon_curr_crit_alarm:
case hwmon_curr_max_alarm:
ret = regmap_field_read(ina->fields[reg], &regval);
if (ret)
return ret;
*val = regval;
return 0;
default:
return -EOPNOTSUPP;
}
}
static int ina3221_write_curr(struct device *dev, u32 attr,
int channel, long val)
{
struct ina3221_data *ina = dev_get_drvdata(dev);
struct ina3221_input *input = &ina->inputs[channel];
int resistance_uo = input->shunt_resistor;
u8 reg = ina3221_curr_reg[attr][channel];
int regval, current_ma, voltage_uv;
/* clamp current */
current_ma = clamp_val(val,
INT_MIN / resistance_uo,
INT_MAX / resistance_uo);
voltage_uv = DIV_ROUND_CLOSEST(current_ma * resistance_uo, 1000);
/* clamp voltage */
voltage_uv = clamp_val(voltage_uv, -163800, 163800);
/* 1 / 40uV(scale) << 3(register shift) = 5 */
regval = DIV_ROUND_CLOSEST(voltage_uv, 5) & 0xfff8;
return regmap_write(ina->regmap, reg, regval);
}
static int ina3221_write_enable(struct device *dev, int channel, bool enable)
{
struct ina3221_data *ina = dev_get_drvdata(dev);
u16 config, mask = INA3221_CONFIG_CHx_EN(channel);
int ret;
config = enable ? mask : 0;
/* Enable or disable the channel */
ret = regmap_update_bits(ina->regmap, INA3221_CONFIG, mask, config);
if (ret)
return ret;
/* Cache the latest config register value */
ret = regmap_read(ina->regmap, INA3221_CONFIG, &ina->reg_config);
if (ret)
return ret;
return 0;
}
static int ina3221_read(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long *val)
{
switch (type) {
case hwmon_in:
/* 0-align channel ID */
return ina3221_read_in(dev, attr, channel - 1, val);
case hwmon_curr:
return ina3221_read_curr(dev, attr, channel, val);
default:
return -EOPNOTSUPP;
}
}
static int ina3221_write(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long val)
{
switch (type) {
case hwmon_in:
/* 0-align channel ID */
return ina3221_write_enable(dev, channel - 1, val);
case hwmon_curr:
return ina3221_write_curr(dev, attr, channel, val);
default:
return -EOPNOTSUPP;
}
}
static int ina3221_read_string(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, const char **str)
{
struct ina3221_data *ina = dev_get_drvdata(dev);
int index = channel - 1;
*str = ina->inputs[index].label;
return 0;
}
static umode_t ina3221_is_visible(const void *drvdata,
enum hwmon_sensor_types type,
u32 attr, int channel)
{
const struct ina3221_data *ina = drvdata;
const struct ina3221_input *input = NULL;
switch (type) {
case hwmon_in:
/* Ignore in0_ */
if (channel == 0)
return 0;
switch (attr) {
case hwmon_in_label:
if (channel - 1 <= INA3221_CHANNEL3)
input = &ina->inputs[channel - 1];
/* Hide label node if label is not provided */
return (input && input->label) ? 0444 : 0;
case hwmon_in_input:
return 0444;
case hwmon_in_enable:
return 0644;
default:
return 0;
}
case hwmon_curr:
switch (attr) {
case hwmon_curr_input:
case hwmon_curr_crit_alarm:
case hwmon_curr_max_alarm:
return 0444;
case hwmon_curr_crit:
case hwmon_curr_max:
return 0644;
default:
return 0;
}
default:
return 0;
}
}
static const u32 ina3221_in_config[] = {
/* 0: dummy, skipped in is_visible */
HWMON_I_INPUT,
/* 1-3: input voltage Channels */
HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
/* 4-6: shunt voltage Channels */
HWMON_I_INPUT,
HWMON_I_INPUT,
HWMON_I_INPUT,
0
};
static const struct hwmon_channel_info ina3221_in = {
.type = hwmon_in,
.config = ina3221_in_config,
};
#define INA3221_HWMON_CURR_CONFIG (HWMON_C_INPUT | \
HWMON_C_CRIT | HWMON_C_CRIT_ALARM | \
HWMON_C_MAX | HWMON_C_MAX_ALARM)
static const u32 ina3221_curr_config[] = {
INA3221_HWMON_CURR_CONFIG,
INA3221_HWMON_CURR_CONFIG,
INA3221_HWMON_CURR_CONFIG,
0
};
static const struct hwmon_channel_info ina3221_curr = {
.type = hwmon_curr,
.config = ina3221_curr_config,
};
static const struct hwmon_channel_info *ina3221_info[] = {
&ina3221_in,
&ina3221_curr,
NULL
};
static const struct hwmon_ops ina3221_hwmon_ops = {
.is_visible = ina3221_is_visible,
.read_string = ina3221_read_string,
.read = ina3221_read,
.write = ina3221_write,
};
static const struct hwmon_chip_info ina3221_chip_info = {
.ops = &ina3221_hwmon_ops,
.info = ina3221_info,
};
/* Extra attribute groups */
static ssize_t ina3221_show_shunt(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
struct ina3221_data *ina = dev_get_drvdata(dev);
unsigned int channel = sd_attr->index;
struct ina3221_input *input = &ina->inputs[channel];
return snprintf(buf, PAGE_SIZE, "%d\n", input->shunt_resistor);
}
static ssize_t ina3221_set_shunt(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
struct ina3221_data *ina = dev_get_drvdata(dev);
unsigned int channel = sd_attr->index;
struct ina3221_input *input = &ina->inputs[channel];
int val;
int ret;
ret = kstrtoint(buf, 0, &val);
if (ret)
return ret;
val = clamp_val(val, 1, INT_MAX);
input->shunt_resistor = val;
return count;
}
/* shunt resistance */
static SENSOR_DEVICE_ATTR(shunt1_resistor, S_IRUGO | S_IWUSR,
ina3221_show_shunt, ina3221_set_shunt, INA3221_CHANNEL1);
static SENSOR_DEVICE_ATTR(shunt2_resistor, S_IRUGO | S_IWUSR,
ina3221_show_shunt, ina3221_set_shunt, INA3221_CHANNEL2);
static SENSOR_DEVICE_ATTR(shunt3_resistor, S_IRUGO | S_IWUSR,
ina3221_show_shunt, ina3221_set_shunt, INA3221_CHANNEL3);
static struct attribute *ina3221_attrs[] = {
&sensor_dev_attr_shunt1_resistor.dev_attr.attr,
&sensor_dev_attr_shunt2_resistor.dev_attr.attr,
&sensor_dev_attr_shunt3_resistor.dev_attr.attr,
NULL,
};
ATTRIBUTE_GROUPS(ina3221);
static const struct regmap_range ina3221_yes_ranges[] = {
regmap_reg_range(INA3221_CONFIG, INA3221_BUS3),
regmap_reg_range(INA3221_MASK_ENABLE, INA3221_MASK_ENABLE),
};
static const struct regmap_access_table ina3221_volatile_table = {
.yes_ranges = ina3221_yes_ranges,
.n_yes_ranges = ARRAY_SIZE(ina3221_yes_ranges),
};
static const struct regmap_config ina3221_regmap_config = {
.reg_bits = 8,
.val_bits = 16,
.cache_type = REGCACHE_RBTREE,
.volatile_table = &ina3221_volatile_table,
};
static int ina3221_probe_child_from_dt(struct device *dev,
struct device_node *child,
struct ina3221_data *ina)
{
struct ina3221_input *input;
u32 val;
int ret;
ret = of_property_read_u32(child, "reg", &val);
if (ret) {
dev_err(dev, "missing reg property of %s\n", child->name);
return ret;
} else if (val > INA3221_CHANNEL3) {
dev_err(dev, "invalid reg %d of %s\n", val, child->name);
return ret;
}
input = &ina->inputs[val];
/* Log the disconnected channel input */
if (!of_device_is_available(child)) {
input->disconnected = true;
return 0;
}
/* Save the connected input label if available */
of_property_read_string(child, "label", &input->label);
/* Overwrite default shunt resistor value optionally */
if (!of_property_read_u32(child, "shunt-resistor-micro-ohms", &val)) {
if (val < 1 || val > INT_MAX) {
dev_err(dev, "invalid shunt resistor value %u of %s\n",
val, child->name);
return -EINVAL;
}
input->shunt_resistor = val;
}
return 0;
}
static int ina3221_probe_from_dt(struct device *dev, struct ina3221_data *ina)
{
const struct device_node *np = dev->of_node;
struct device_node *child;
int ret;
/* Compatible with non-DT platforms */
if (!np)
return 0;
for_each_child_of_node(np, child) {
ret = ina3221_probe_child_from_dt(dev, child, ina);
if (ret)
return ret;
}
return 0;
}
static int ina3221_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct device *dev = &client->dev;
struct ina3221_data *ina;
struct device *hwmon_dev;
int i, ret;
ina = devm_kzalloc(dev, sizeof(*ina), GFP_KERNEL);
if (!ina)
return -ENOMEM;
ina->regmap = devm_regmap_init_i2c(client, &ina3221_regmap_config);
if (IS_ERR(ina->regmap)) {
dev_err(dev, "Unable to allocate register map\n");
return PTR_ERR(ina->regmap);
}
for (i = 0; i < F_MAX_FIELDS; i++) {
ina->fields[i] = devm_regmap_field_alloc(dev,
ina->regmap,
ina3221_reg_fields[i]);
if (IS_ERR(ina->fields[i])) {
dev_err(dev, "Unable to allocate regmap fields\n");
return PTR_ERR(ina->fields[i]);
}
}
for (i = 0; i < INA3221_NUM_CHANNELS; i++)
ina->inputs[i].shunt_resistor = INA3221_RSHUNT_DEFAULT;
ret = ina3221_probe_from_dt(dev, ina);
if (ret) {
dev_err(dev, "Unable to probe from device tree\n");
return ret;
}
ret = regmap_field_write(ina->fields[F_RST], true);
if (ret) {
dev_err(dev, "Unable to reset device\n");
return ret;
}
/* Sync config register after reset */
ret = regmap_read(ina->regmap, INA3221_CONFIG, &ina->reg_config);
if (ret)
return ret;
/* Disable channels if their inputs are disconnected */
for (i = 0; i < INA3221_NUM_CHANNELS; i++) {
if (ina->inputs[i].disconnected)
ina->reg_config &= ~INA3221_CONFIG_CHx_EN(i);
}
ret = regmap_write(ina->regmap, INA3221_CONFIG, ina->reg_config);
if (ret)
return ret;
dev_set_drvdata(dev, ina);
hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, ina,
&ina3221_chip_info,
ina3221_groups);
if (IS_ERR(hwmon_dev)) {
dev_err(dev, "Unable to register hwmon device\n");
return PTR_ERR(hwmon_dev);
}
return 0;
}
static int __maybe_unused ina3221_suspend(struct device *dev)
{
struct ina3221_data *ina = dev_get_drvdata(dev);
int ret;
/* Save config register value and enable cache-only */
ret = regmap_read(ina->regmap, INA3221_CONFIG, &ina->reg_config);
if (ret)
return ret;
/* Set to power-down mode for power saving */
ret = regmap_update_bits(ina->regmap, INA3221_CONFIG,
INA3221_CONFIG_MODE_MASK,
INA3221_CONFIG_MODE_POWERDOWN);
if (ret)
return ret;
regcache_cache_only(ina->regmap, true);
regcache_mark_dirty(ina->regmap);
return 0;
}
static int __maybe_unused ina3221_resume(struct device *dev)
{
struct ina3221_data *ina = dev_get_drvdata(dev);
int ret;
regcache_cache_only(ina->regmap, false);
/* Software reset the chip */
ret = regmap_field_write(ina->fields[F_RST], true);
if (ret) {
dev_err(dev, "Unable to reset device\n");
return ret;
}
/* Restore cached register values to hardware */
ret = regcache_sync(ina->regmap);
if (ret)
return ret;
/* Restore config register value to hardware */
ret = regmap_write(ina->regmap, INA3221_CONFIG, ina->reg_config);
if (ret)
return ret;
return 0;
}
static const struct dev_pm_ops ina3221_pm = {
SET_SYSTEM_SLEEP_PM_OPS(ina3221_suspend, ina3221_resume)
};
static const struct of_device_id ina3221_of_match_table[] = {
{ .compatible = "ti,ina3221", },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, ina3221_of_match_table);
static const struct i2c_device_id ina3221_ids[] = {
{ "ina3221", 0 },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(i2c, ina3221_ids);
static struct i2c_driver ina3221_i2c_driver = {
.probe = ina3221_probe,
.driver = {
.name = INA3221_DRIVER_NAME,
.of_match_table = ina3221_of_match_table,
.pm = &ina3221_pm,
},
.id_table = ina3221_ids,
};
module_i2c_driver(ina3221_i2c_driver);
MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
MODULE_DESCRIPTION("Texas Instruments INA3221 HWMon Driver");
MODULE_LICENSE("GPL v2");