Re: [PATCH v3 2/2] hwmon: Add support for INA3221 Triple Current/Voltage Monitors
From: Guenter Roeck
Date: Sun May 15 2016 - 11:37:29 EST
On 04/25/2016 12:39 PM, Andrew F. Davis wrote:
Add support for the the INA3221 26v capable, Triple channel,
Bi-Directional, Zero-Drift, Low-/High-Side, Current/Voltage Monitor
with I2C interface.
Signed-off-by: Andrew F. Davis <afd@xxxxxx>
---
Documentation/hwmon/ina3221 | 35 ++++
drivers/hwmon/Kconfig | 11 ++
drivers/hwmon/Makefile | 1 +
drivers/hwmon/ina3221.c | 423 ++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 470 insertions(+)
create mode 100644 Documentation/hwmon/ina3221
create mode 100644 drivers/hwmon/ina3221.c
diff --git a/Documentation/hwmon/ina3221 b/Documentation/hwmon/ina3221
new file mode 100644
index 0000000..0ff7485
--- /dev/null
+++ b/Documentation/hwmon/ina3221
@@ -0,0 +1,35 @@
+Kernel driver ina3221
+=====================
+
+Supported chips:
+ * Texas Instruments INA3221
+ Prefix: 'ina3221'
+ Addresses: I2C 0x40 - 0x43
+ Datasheet: Publicly available at the Texas Instruments website
+ http://www.ti.com/
+
+Author: Andrew F. Davis <afd@xxxxxx>
+
+Description
+-----------
+
+The Texas Instruments INA3221 monitors voltage, current, and power on the high
+side of up to three D.C. power supplies. The INA3221 monitors both shunt drop
+and supply voltage, with programmable conversion times and averaging, current
+and power are calculated host-side from these.
+
+Sysfs entries
+-------------
+
+in[123]_input Bus voltage(mV) channels
+curr[123]_input Current(mA) measurement channels
+shunt[123]_resistor Shunt resistance(uOhm) channels
+curr[123]_crit Critical alert current(mA) setting, activates the
+ corresponding alarm when the respective current
+ is above this value
+curr[123]_crit_alarm Critical alert current limit exceeded
+curr[123]_max Warning alert current(mA) setting, activates the
+ corresponding alarm when the respective current
+ average is above this value.
+curr[123]_max_alarm Warning alert current limit exceeded
+in[456]_input Shunt voltage(uV) for channels 1, 2, and 3 respectively
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 5c2d13a..de08242 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1503,6 +1503,17 @@ config SENSORS_INA2XX
This driver can also be built as a module. If so, the module
will be called ina2xx.
+config SENSORS_INA3221
+ tristate "Texas Instruments INA3221 Triple Power Monitor"
+ depends on I2C
+ select REGMAP_I2C
+ help
+ If you say yes here you get support for the TI INA3221 Triple Power
+ Monitor.
+
+ This driver can also be built as a module. If so, the module
+ will be called ina3221.
+
config SENSORS_TC74
tristate "Microchip TC74"
depends on I2C
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 58cc3ac..83e8ab0 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -77,6 +77,7 @@ obj-$(CONFIG_SENSORS_IBMPOWERNV)+= ibmpowernv.o
obj-$(CONFIG_SENSORS_IIO_HWMON) += iio_hwmon.o
obj-$(CONFIG_SENSORS_INA209) += ina209.o
obj-$(CONFIG_SENSORS_INA2XX) += ina2xx.o
+obj-$(CONFIG_SENSORS_INA3221) += ina3221.o
obj-$(CONFIG_SENSORS_IT87) += it87.o
obj-$(CONFIG_SENSORS_JC42) += jc42.o
obj-$(CONFIG_SENSORS_JZ4740) += jz4740-hwmon.o
diff --git a/drivers/hwmon/ina3221.c b/drivers/hwmon/ina3221.c
new file mode 100644
index 0000000..389a6ba
--- /dev/null
+++ b/drivers/hwmon/ina3221.c
@@ -0,0 +1,423 @@
+/*
+ * INA3221 Triple Current/Voltage Monitor
+ *
+ * Copyright (C) 2016 Texas Instruments Incorporated - http://www.ti.com/
+ * Andrew F. Davis <afd@xxxxxx>
+ *
+ * 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_SHUNT BIT(1)
+#define INA3221_CONFIG_MODE_BUS BIT(2)
+#define INA3221_CONFIG_MODE_CONTINUOUS BIT(3)
+
+#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
+};
+
+static const unsigned int register_channel[] = {
+ [INA3221_SHUNT1] = INA3221_CHANNEL1,
+ [INA3221_SHUNT2] = INA3221_CHANNEL2,
+ [INA3221_SHUNT3] = INA3221_CHANNEL3,
+ [INA3221_CRIT1] = INA3221_CHANNEL1,
+ [INA3221_CRIT2] = INA3221_CHANNEL2,
+ [INA3221_CRIT3] = INA3221_CHANNEL3,
+ [INA3221_WARN1] = INA3221_CHANNEL1,
+ [INA3221_WARN2] = INA3221_CHANNEL2,
+ [INA3221_WARN3] = INA3221_CHANNEL3,
+};
+
+/**
+ * struct ina3221_data - device specific information
+ * @regmap: Register map of the device
+ * @fields: Register fields of the device
+ * @shunt_resistors: Array of resistor values per channel
+ */
+struct ina3221_data {
+ struct regmap *regmap;
+ struct regmap_field *fields[F_MAX_FIELDS];
+ unsigned int shunt_resistors[INA3221_NUM_CHANNELS];
+};
+
+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, ®val);
+ if (ret)
+ return ret;
+
+ *val = sign_extend32(regval >> 3, 12);
+
+ return 0;
+}
+
+static ssize_t ina3221_show_bus_voltage(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 reg = sd_attr->index;
+ int val, voltage_mv, ret;
+
+ ret = ina3221_read_value(ina, reg, &val);
+ if (ret)
+ return ret;
+
+ voltage_mv = val * 8;
+
+ return snprintf(buf, PAGE_SIZE, "%d\n", voltage_mv);
+}
+
+static ssize_t ina3221_show_shunt_voltage(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 reg = sd_attr->index;
+ int val, voltage_uv, ret;
+
+ ret = ina3221_read_value(ina, reg, &val);
+ if (ret)
+ return ret;
+ voltage_uv = val * 40;
+
+ return snprintf(buf, PAGE_SIZE, "%d\n", voltage_uv);
+}
+
+static ssize_t ina3221_show_current(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 reg = sd_attr->index;
+ unsigned int channel = register_channel[reg];
+ unsigned int resistance_uo = ina->shunt_resistors[channel];
+ int val, current_ma, voltage_nv, ret;
+
+ ret = ina3221_read_value(ina, reg, &val);
+ if (ret)
+ return ret;
+ voltage_nv = val * 40000;
+
+ current_ma = DIV_ROUND_CLOSEST(voltage_nv, resistance_uo);
+
+ return snprintf(buf, PAGE_SIZE, "%d\n", current_ma);
+}
+
+static ssize_t ina3221_set_current(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 reg = sd_attr->index;
+ unsigned int channel = register_channel[reg];
+ unsigned int resistance_uo = ina->shunt_resistors[channel];
+ int val, current_ma, voltage_uv, ret;
+
+ ret = kstrtoint(buf, 0, ¤t_ma);
+ if (ret)
+ return ret;
+
+ voltage_uv = DIV_ROUND_CLOSEST(current_ma * resistance_uo, 1000);
This can easily overflow. Clamping the result after the overflow
already occurred doesn't help much. To avoid this, you would either
have to use 64 bit operations, or clamp current_ma first, to
something like [0, U32_MAX/resistance_uo].
+
+ /* clamp value */
+ voltage_uv = (voltage_uv > 163800) ? 163800 : voltage_uv;
+ voltage_uv = (voltage_uv < -163800) ? -163800 : voltage_uv;
+
Please use clamp_val().
+ /* 1 / 40uV(scale) << 3(register shift) = 5 */
+ val = DIV_ROUND_CLOSEST(voltage_uv, 5) & 0xfff8;
+
+ ret = regmap_write(ina->regmap, reg, val);
+ if (ret)
+ return ret;
+
+ return count;
+}
+
+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;
+ unsigned int resistance_uo;
+
+ resistance_uo = ina->shunt_resistors[channel];
+
+ return snprintf(buf, PAGE_SIZE, "%d\n", resistance_uo);
+}
+
+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;
+ unsigned int val;
+ int ret;
+
+ ret = kstrtouint(buf, 0, &val);
+ if (ret)
+ return ret;
+
+ if (val == 0)
+ return -EINVAL;
+
+ ina->shunt_resistors[channel] = val;
+
Accepting unlimited shunt resistor values can result in overflows elsewhere,
whenever a 32 bit value is multiplied with it (ina3221_set_current is the one
example I found). It might make sense to limit the range to something
reasonable.
+ return count;
+}
+
+static ssize_t ina3221_show_alert(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 field = sd_attr->index;
+ unsigned int regval;
+ int ret;
+
+ ret = regmap_field_read(ina->fields[field], ®val);
+ if (ret)
+ return ret;
+
+ return snprintf(buf, PAGE_SIZE, "%d\n", regval);
+}
+
+/* bus voltage */
+static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, ina3221_show_bus_voltage, NULL, INA3221_BUS1);
+static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, ina3221_show_bus_voltage, NULL, INA3221_BUS2);
+static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, ina3221_show_bus_voltage, NULL, INA3221_BUS3);
+
+/* calculated current */
+static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, ina3221_show_current, NULL, INA3221_SHUNT1);
+static SENSOR_DEVICE_ATTR(curr2_input, S_IRUGO, ina3221_show_current, NULL, INA3221_SHUNT2);
+static SENSOR_DEVICE_ATTR(curr3_input, S_IRUGO, ina3221_show_current, NULL, INA3221_SHUNT3);
+
+/* 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);
+
Unnecessary ( )
+/* critical current */
+static SENSOR_DEVICE_ATTR(curr1_crit, (S_IRUGO | S_IWUSR), ina3221_show_current, ina3221_set_current, INA3221_CRIT1);
+static SENSOR_DEVICE_ATTR(curr2_crit, (S_IRUGO | S_IWUSR), ina3221_show_current, ina3221_set_current, INA3221_CRIT2);
+static SENSOR_DEVICE_ATTR(curr3_crit, (S_IRUGO | S_IWUSR), ina3221_show_current, ina3221_set_current, INA3221_CRIT3);
+
+/* critical current alert */
+static SENSOR_DEVICE_ATTR(curr1_crit_alarm, S_IRUGO, ina3221_show_alert, NULL, F_CF1);
+static SENSOR_DEVICE_ATTR(curr2_crit_alarm, S_IRUGO, ina3221_show_alert, NULL, F_CF2);
+static SENSOR_DEVICE_ATTR(curr3_crit_alarm, S_IRUGO, ina3221_show_alert, NULL, F_CF3);
+
+/* warning current */
+static SENSOR_DEVICE_ATTR(curr1_max, (S_IRUGO | S_IWUSR), ina3221_show_current, ina3221_set_current, INA3221_WARN1);
+static SENSOR_DEVICE_ATTR(curr2_max, (S_IRUGO | S_IWUSR), ina3221_show_current, ina3221_set_current, INA3221_WARN2);
+static SENSOR_DEVICE_ATTR(curr3_max, (S_IRUGO | S_IWUSR), ina3221_show_current, ina3221_set_current, INA3221_WARN3);
+
+/* warning current alert */
+static SENSOR_DEVICE_ATTR(curr1_max_alarm, S_IRUGO, ina3221_show_alert, NULL, F_WF1);
+static SENSOR_DEVICE_ATTR(curr2_max_alarm, S_IRUGO, ina3221_show_alert, NULL, F_WF2);
+static SENSOR_DEVICE_ATTR(curr3_max_alarm, S_IRUGO, ina3221_show_alert, NULL, F_WF3);
+
+/* shunt voltage */
+static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, ina3221_show_shunt_voltage, NULL, INA3221_SHUNT1);
+static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, ina3221_show_shunt_voltage, NULL, INA3221_SHUNT2);
+static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, ina3221_show_shunt_voltage, NULL, INA3221_SHUNT3);
+
Please avoid lines over 80 characters.
+static struct attribute *ina3221_attrs[] = {
+ /* channel 1 */
+ &sensor_dev_attr_in1_input.dev_attr.attr,
+ &sensor_dev_attr_curr1_input.dev_attr.attr,
+ &sensor_dev_attr_shunt1_resistor.dev_attr.attr,
+ &sensor_dev_attr_curr1_crit.dev_attr.attr,
+ &sensor_dev_attr_curr1_crit_alarm.dev_attr.attr,
+ &sensor_dev_attr_curr1_max.dev_attr.attr,
+ &sensor_dev_attr_curr1_max_alarm.dev_attr.attr,
+ &sensor_dev_attr_in4_input.dev_attr.attr,
+
+ /* channel 2 */
+ &sensor_dev_attr_in2_input.dev_attr.attr,
+ &sensor_dev_attr_curr2_input.dev_attr.attr,
+ &sensor_dev_attr_shunt2_resistor.dev_attr.attr,
+ &sensor_dev_attr_curr2_crit.dev_attr.attr,
+ &sensor_dev_attr_curr2_crit_alarm.dev_attr.attr,
+ &sensor_dev_attr_curr2_max.dev_attr.attr,
+ &sensor_dev_attr_curr2_max_alarm.dev_attr.attr,
+ &sensor_dev_attr_in5_input.dev_attr.attr,
+
+ /* channel 3 */
+ &sensor_dev_attr_in3_input.dev_attr.attr,
+ &sensor_dev_attr_curr3_input.dev_attr.attr,
+ &sensor_dev_attr_shunt3_resistor.dev_attr.attr,
+ &sensor_dev_attr_curr3_crit.dev_attr.attr,
+ &sensor_dev_attr_curr3_crit_alarm.dev_attr.attr,
+ &sensor_dev_attr_curr3_max.dev_attr.attr,
+ &sensor_dev_attr_curr3_max_alarm.dev_attr.attr,
+ &sensor_dev_attr_in6_input.dev_attr.attr,
+
+ NULL,
+};
+ATTRIBUTE_GROUPS(ina3221);
+
+static const struct regmap_range ina3221_yes_ranges[] = {
+ regmap_reg_range(INA3221_SHUNT1, 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(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++) {
+ ret = of_property_read_u32_index(client->dev.of_node,
+ "shunt-resistors", i,
+ &ina->shunt_resistors[i]);
+ if (ret || ina->shunt_resistors[i] == 0)
+ ina->shunt_resistors[i] = INA3221_RSHUNT_DEFAULT;
+ }
+
+ ret = regmap_field_write(ina->fields[F_RST], true);
+ if (ret) {
+ dev_err(dev, "Unable to reset device\n");
+ return ret;
+ }
+
+ hwmon_dev = devm_hwmon_device_register_with_groups(dev,
+ client->name,
+ ina, ina3221_groups);
+ if (IS_ERR(hwmon_dev)) {
+ dev_err(dev, "Unable to register hwmon device\n");
+ return PTR_ERR(hwmon_dev);
+ }
+
+ return 0;
+}
+
+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,
+ },
+ .id_table = ina3221_ids,
+};
+module_i2c_driver(ina3221_i2c_driver);
+
+MODULE_AUTHOR("Andrew F. Davis <afd@xxxxxx>");
+MODULE_DESCRIPTION("Texas Instruments INA3221 HWMon Driver");
+MODULE_LICENSE("GPL v2");