[lm-sensors] [PATCH] hwmon: INA219 and INA226 support

* [lm-sensors] [PATCH] hwmon: INA219 and INA226 support
@ 2012-05-08 17:43 Felten, Lothar
  2012-05-08 17:49 ` Guenter Roeck
                   ` (5 more replies)
  0 siblings, 6 replies; 7+ messages in thread
From: Felten, Lothar @ 2012-05-08 17:43 UTC (permalink / raw)
  To: lm-sensors

Hello,

This patch brings support for the Texas Instruments INA219 and INA226 power monitors.

Signed-off-by: Lothar Felten <l-felten@ti.com>
--
diff -uprN linux-3.3.4/Documentation/hwmon/ina2xx b/Documentation/hwmon/ina2xx

--- linux-3.3.4/Documentation/hwmon/ina2xx      1970-01-01 01:00:00.000000000 +0100
+++ b/Documentation/hwmon/ina2xx        2012-05-07 15:27:56.142307748 +0200
@@ -0,0 +1,29 @@
+Kernel driver ina2xx
+==========
+
+Supported chips:
+  * Texas Instruments INA219
+    Prefix: 'ina219'
+    Addresses: I2C 0x40 - 0x4f
+    Datasheet: Publicly available at the Texas Instruments website
+               http://www.ti.com/
+
+  * Texas Instruments INA226
+    Prefix: 'ina226'
+    Addresses: I2C 0x40 - 0x4f
+    Datasheet: Publicly available at the Texas Instruments website
+               http://www.ti.com/
+
+Author: Lothar Felten <l-felten@ti.com>
+
+Description
+-----------
+
+The INA219 is a high-side current shunt and power monitor with an I2C
+interface. The INA219 monitors both shunt drop and supply voltage, with
+programmable conversion times and filtering.
+
+The INA226 is a current shunt and power monitor with an I2C interface.
+The INA226 monitors both a shunt voltage drop and bus supply voltage.
+
+The shunt value in milliohms can be set via the kernel config.
diff -uprN linux-3.3.4/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c
--- linux-3.3.4/drivers/hwmon/ina2xx.c  1970-01-01 01:00:00.000000000 +0100
+++ b/drivers/hwmon/ina2xx.c    2012-05-08 19:02:26.305202216 +0200
@@ -0,0 +1,369 @@
+/*
+ * Driver for Texas Instruments INA219, INA226 power monitor chips
+ *
+ * INA219:
+ * Zero Drift Bi-Directional Current/Power Monitor with I2C Interface
+ * Datasheet: http://www.ti.com/product/ina219
+ *
+ * INA226:
+ * Bi-Directional Current/Power Monitor with I2C Interface
+ * Datasheet: http://www.ti.com/product/ina226
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+
+#include <linux/platform_data/ina2xx.h>
+
+/* common register definitions */
+#define INA2XX_CONFIG                  0x00
+#define INA2XX_SHUNT_VOLTAGE           0x01 /* readonly */
+#define INA2XX_BUS_VOLTAGE             0x02 /* readonly */
+#define INA2XX_POWER                   0x03 /* readonly */
+#define INA2XX_CURRENT                 0x04 /* readonly */
+#define INA2XX_CALIBRATION             0x05
+
+/* INA226 register definitions */
+#define INA226_MASK_ENABLE             0x06
+#define INA226_ALERT_LIMIT             0x07
+#define INA226_DIE_ID                  0xFF
+
+
+/* register count */
+#define INA219_REGISTERS               6
+#define INA226_REGISTERS               8
+
+#define INA2XX_MAX_REGISTERS           8
+
+/* settings - depend on use case */
+#define INA219_CONFIG_DEFAULT          0x219F  /* PGA=1 */
+#define INA226_CONFIG_DEFAULT          0x4527  /* averages\x16 */
+
+/* worst case is 68.10 ms (~14.6Hz, ina219) */
+#define INA2XX_CONVERSION_RATE         15
+
+enum ina2xx_ids { ina219, ina226 };
+
+struct ina2xx_data {
+       struct device *hwmon_dev;
+
+       struct mutex update_lock;
+       bool valid;
+       unsigned long last_updated;
+
+       int kind;
+       int registers;
+       u16 regs[INA2XX_MAX_REGISTERS];
+};
+
+int ina2xx_read_word(struct i2c_client *client, int reg)
+{
+       int val = i2c_smbus_read_word_data(client, reg);
+       if (unlikely(val < 0)) {
+               dev_dbg(&client->dev,
+                       "Failed to read register: %d\n", reg);
+               return val;
+       }
+       return be16_to_cpu(val);
+}
+
+void ina2xx_write_word(struct i2c_client *client, int reg, int data)
+{
+       i2c_smbus_write_word_data(client, reg, cpu_to_be16(data));
+}
+
+static struct ina2xx_data *ina2xx_update_device(struct device *dev)
+{
+       struct i2c_client *client = to_i2c_client(dev);
+       struct ina2xx_data *data = i2c_get_clientdata(client);
+       struct ina2xx_data *ret = data;
+
+       mutex_lock(&data->update_lock);
+
+       if (time_after(jiffies, data->last_updated +
+               HZ / INA2XX_CONVERSION_RATE) || !data->valid) {
+
+               int i;
+
+               dev_dbg(&client->dev, "Starting ina2xx update\n");
+
+               /* Read all registers */
+               for (i = 0; i < data->registers; i++) {
+                       int rv = ina2xx_read_word(client, i);
+                       if (rv < 0) {
+                               ret = ERR_PTR(rv);
+                               goto abort;
+                       }
+                       data->regs[i] = rv;
+               }
+               data->last_updated = jiffies;
+               data->valid = 1;
+       }
+abort:
+       mutex_unlock(&data->update_lock);
+       return ret;
+}
+
+static int ina219_get_value(struct ina2xx_data *data, u8 reg)
+{
+       /*
+        * calculate exact value for the given register
+        * we assume default power-on reset settings:
+        * bus voltage range 32V
+        * gain = /8
+        * adc 1 & 2 -> conversion time 532uS
+        * mode is continuous shunt and bus
+        * calibration value is INA219_CALIBRATION_VALUE
+        */
+       int val = data->regs[reg];
+
+       switch (reg) {
+       case INA2XX_SHUNT_VOLTAGE:
+               /* LSB\x10uV. Convert to mV. */
+               val = DIV_ROUND_CLOSEST(val, 100);
+               break;
+       case INA2XX_BUS_VOLTAGE:
+               /* LSB=4mV. Register is not right aligned, convert to mV. */
+               val = (val >> 3) * 4;
+               break;
+       case INA2XX_POWER:
+               /* LSB mW. Convert to uW */
+               val = val * 20 * 1000;
+               break;
+       case INA2XX_CURRENT:
+               /* LSB=1mA (selected). Is in mA */
+               break;
+       default:
+               /* programmer goofed */
+               WARN_ON_ONCE(1);
+               val = 0;
+               break;
+       }
+
+       return val;
+}
+
+static int ina226_get_value(struct ina2xx_data *data, u8 reg)
+{
+       /*
+        * calculate exact value for the given register
+        * we assume default power-on reset settings:
+        * bus voltage range 32V
+        * gain = /8
+        * adc 1 & 2 -> conversion time 532uS
+        * mode is continuous shunt and bus
+        * calibration value is INA226_CALIBRATION_VALUE
+        */
+       int val = data->regs[reg];
+
+       switch (reg) {
+       case INA2XX_SHUNT_VOLTAGE:
+               /* LSB=2.5uV. Convert to mV. */
+               val = DIV_ROUND_CLOSEST(val, 400);
+               break;
+       case INA2XX_BUS_VOLTAGE:
+               /* LSB=1.25mV. Convert to mV. */
+               val = val + DIV_ROUND_CLOSEST(val, 4);
+               break;
+       case INA2XX_POWER:
+               /* LSB%mW. Convert to uW */
+               val = val * 25 * 1000;
+               break;
+       case INA2XX_CURRENT:
+               /* LSB=1mA (selected). Is in mA */
+               break;
+       default:
+               /* programmer goofed */
+               WARN_ON_ONCE(1);
+               val = 0;
+               break;
+       }
+
+       return val;
+}
+
+static ssize_t ina2xx_show_value(struct device *dev,
+                                 struct device_attribute *da, char *buf)
+{
+       struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
+       struct ina2xx_data *data = ina2xx_update_device(dev);
+       int value = 0;
+
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+
+       switch (data->kind) {
+       case ina219:
+               value = ina219_get_value(data, attr->index);
+               break;
+       case ina226:
+               value = ina226_get_value(data, attr->index);
+               break;
+       default:
+               WARN_ON_ONCE(1);
+               break;
+       }
+       return snprintf(buf, PAGE_SIZE, "%d\n", value);
+}
+
+/* shunt voltage */
+static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, \
+       ina2xx_show_value, NULL, INA2XX_SHUNT_VOLTAGE);
+
+/* bus voltage */
+static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, \
+       ina2xx_show_value, NULL, INA2XX_BUS_VOLTAGE);
+
+/* calculated current */
+static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, \
+       ina2xx_show_value, NULL, INA2XX_CURRENT);
+
+/* calculated power */
+static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, \
+       ina2xx_show_value, NULL, INA2XX_POWER);
+
+/* pointers to created device attributes */
+static struct attribute *ina2xx_attributes[] = {
+       &sensor_dev_attr_in0_input.dev_attr.attr,
+       &sensor_dev_attr_in1_input.dev_attr.attr,
+       &sensor_dev_attr_curr1_input.dev_attr.attr,
+       &sensor_dev_attr_power1_input.dev_attr.attr,
+       NULL,
+};
+
+static const struct attribute_group ina2xx_group = {
+       .attrs = ina2xx_attributes,
+};
+
+static int ina2xx_probe(struct i2c_client *client,
+                        const struct i2c_device_id *id)
+{
+       struct i2c_adapter *adapter = client->adapter;
+       struct ina2xx_data *data;
+       struct ina2xx_platform_data *pdata;
+       int ret = 0;
+       long shunt = 10000; /* default shunt value 10mOhms */
+
+       if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
+               return -ENODEV;
+
+       data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
+       if (!data)
+               return -ENOMEM;
+
+       if (client->dev.platform_data) {
+               pdata = (struct ina2xx_platform_data *)
+                       client->dev.platform_data;
+               shunt = pdata->shunt_uohms;
+       }
+
+       if (shunt <= 0)
+               return -ENODEV;
+
+       /* set the device type */
+       data->kind = id->driver_data;
+
+       switch (data->kind) {
+       case ina219:
+               /* device configuration */
+               ina2xx_write_word(client, INA2XX_CONFIG, INA219_CONFIG_DEFAULT);
+
+               /* set current LSB to 1mA, shunt is in uOhms */
+               /* (equation 13 in datasheet) */
+               ina2xx_write_word(client, INA2XX_CALIBRATION, (40960 / shunt));
+               dev_info(&client->dev,
+                       "power monitor INA219 (Rshunt = %li uOhm)\n", shunt);
+               data->registers = INA219_REGISTERS;
+               break;
+       case ina226:
+               /* device configuration */
+               ina2xx_write_word(client, INA2XX_CONFIG, INA226_CONFIG_DEFAULT);
+
+               /* set current LSB to 1mA, shunt is in uOhms */
+               /* (equation 1 in datasheet)*/
+               ina2xx_write_word(client, INA2XX_CALIBRATION, (5120 / shunt));
+               dev_info(&client->dev,
+                       "power monitor INA226 (Rshunt = %li uOhm)\n", shunt);
+               data->registers = INA226_REGISTERS;
+               break;
+       default:
+               /* unknown device id */
+               return -ENODEV;
+       }
+
+       i2c_set_clientdata(client, data);
+       mutex_init(&data->update_lock);
+
+       ret = sysfs_create_group(&client->dev.kobj, &ina2xx_group);
+       if (ret)
+               return ret;
+
+       data->hwmon_dev = hwmon_device_register(&client->dev);
+       if (IS_ERR(data->hwmon_dev)) {
+               ret = PTR_ERR(data->hwmon_dev);
+               goto out_err_hwmon;
+
+       }
+
+       return 0;
+
+out_err_hwmon:
+       sysfs_remove_group(&client->dev.kobj, &ina2xx_group);
+       return ret;
+}
+
+static int ina2xx_remove(struct i2c_client *client)
+{
+       struct ina2xx_data *data = i2c_get_clientdata(client);
+
+       hwmon_device_unregister(data->hwmon_dev);
+       sysfs_remove_group(&client->dev.kobj, &ina2xx_group);
+
+       return 0;
+}
+
+static const struct i2c_device_id ina2xx_id[] = {
+       { "ina219", ina219 },
+       { "ina226", ina226 },
+       { }
+}
+MODULE_DEVICE_TABLE(i2c, ina2xx_id);
+
+static struct i2c_driver ina2xx_driver = {
+       .driver = {
+               .name   = "ina2xx",
+       },
+       .probe          = ina2xx_probe,
+       .remove         = ina2xx_remove,
+       .id_table       = ina2xx_id,
+};
+
+static int __init ina2xx_init(void)
+{
+       return i2c_add_driver(&ina2xx_driver);
+}
+
+static void __exit ina2xx_exit(void)
+{
+       i2c_del_driver(&ina2xx_driver);
+}
+
+MODULE_AUTHOR("Lothar Felten <l-felten@ti.com>");
+MODULE_DESCRIPTION("ina2xx driver");
+MODULE_LICENSE("GPL");
+
+module_init(ina2xx_init);
+module_exit(ina2xx_exit);
diff -uprN linux-3.3.4/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
--- linux-3.3.4/drivers/hwmon/Kconfig   2012-04-27 19:17:35.000000000 +0200
+++ b/drivers/hwmon/Kconfig     2012-05-08 17:37:10.385113357 +0200
@@ -1088,6 +1088,19 @@ config SENSORS_AMC6821
          This driver can also be build as a module.  If so, the module
          will be called amc6821.

+config SENSORS_INA2XX
+       tristate "Texas Instruments INA219, INA226"
+       depends on I2C && EXPERIMENTAL
+       help
+         If you say yes here you get support for INA219 and INA226 power
+         monitor chips.
+
+         The INA2xx driver is configured for the default configuration of
+         the part as described in the datasheet.
+         Default value for Rshunt is 10 mOhms.
+         This driver can also be built as a module.  If so, the module
+         will be called ina2xx.
+
 config SENSORS_THMC50
        tristate "Texas Instruments THMC50 / Analog Devices ADM1022"
        depends on I2C
diff -uprN linux-3.3.4/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
--- linux-3.3.4/drivers/hwmon/Makefile  2012-04-27 19:17:35.000000000 +0200
+++ b/drivers/hwmon/Makefile    2012-05-07 17:08:52.978200050 +0200
@@ -62,6 +62,7 @@ obj-$(CONFIG_SENSORS_ULTRA45) += ultra45
 obj-$(CONFIG_SENSORS_I5K_AMB)  += i5k_amb.o
 obj-$(CONFIG_SENSORS_IBMAEM)   += ibmaem.o
 obj-$(CONFIG_SENSORS_IBMPEX)   += ibmpex.o
+obj-$(CONFIG_SENSORS_INA2XX)   += ina2xx.o
 obj-$(CONFIG_SENSORS_IT87)     += it87.o
 obj-$(CONFIG_SENSORS_JC42)     += jc42.o
 obj-$(CONFIG_SENSORS_JZ4740)   += jz4740-hwmon.o
diff -uprN linux-3.3.4/include/linux/platform_data/ina2xx.h b/include/linux/platform_data/ina2xx.h
--- linux-3.3.4/include/linux/platform_data/ina2xx.h    1970-01-01 01:00:00.000000000 +0100
+++ b/include/linux/platform_data/ina2xx.h      2012-05-08 12:36:48.616800341 +0200
@@ -0,0 +1,20 @@
+/*
+ * Driver for Texas Instruments INA219, INA226 power monitor chips
+ *
+ * Copyright (C) 2012 Lothar Felten <l-felten@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.
+ *
+ * For further information, see the Documentation/hwmon/ina2xx file.
+ */
+
+/**
+ * struct ina2xx_platform_data - ina2xx info
+ * @shunt_uohms                shunt resistance in microohms
+ */
+struct ina2xx_platform_data {
+       long shunt_uohms;
+};
+

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