hwmon: ina219: powermon driver for TI ina219

checking in hwmon driver for TI power monitor device INA219

bug 808311

Change-Id: Idc7a4d6b4fd867db5dc64dc09d6b1f847f9276f4
Reviewed-on: http://git-master/r/34293
Tested-by: Venu Byravarasu <vbyravarasu@nvidia.com>
Reviewed-by: Sachin Nikam <snikam@nvidia.com>
Reviewed-by: Bitan Biswas <bbiswas@nvidia.com>
Reviewed-by: Narendra Damahe <ndamahe@nvidia.com>

Rebase-Id: R3c8f5eea54a0e3c6d1bc0a9283260f12cf865fc1

3 files changed, 413 insertions, 0 deletions

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 42e077c4dfeb..3711728f212c 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1337,6 +1337,13 @@ config SENSORS_MC13783_ADC
         help
           Support for the A/D converter on MC13783 PMIC.
 
+config SENSORS_INA219
+	tristate "Texas Instruments INA219 POWER MONITOR SENSOR DRIVER"
+	depends on I2C
+	default n
+	help
+		Support for the TI INA219 power monitor sensor.
+
 if ACPI
 
 comment "ACPI drivers"
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 665a82fd1f91..5f6f6e6ae771 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -124,6 +124,7 @@ obj-$(CONFIG_SENSORS_W83L785TS)	+= w83l785ts.o
 obj-$(CONFIG_SENSORS_W83L786NG)	+= w83l786ng.o
 obj-$(CONFIG_SENSORS_WM831X)	+= wm831x-hwmon.o
 obj-$(CONFIG_SENSORS_WM8350)	+= wm8350-hwmon.o
+obj-$(CONFIG_SENSORS_INA219)	+= ina219.o
 
 obj-$(CONFIG_PMBUS)		+= pmbus/
 
diff --git a/drivers/hwmon/ina219.c b/drivers/hwmon/ina219.c
new file mode 100644
index 000000000000..cd7dbdf10589
--- /dev/null
+++ b/drivers/hwmon/ina219.c
@@ -0,0 +1,405 @@
+/*
+ * ina219.c - driver for TI INA219 current / power monitor sensor
+ *
+ * Copyright (c) 2011, NVIDIA Corporation.
+ *
+ * The INA219 is a sensor chip made by Texas Instruments. It measures
+ * power, voltage and current on a power rail.
+ * Complete datasheet can be obtained from website:
+ *   http://focus.ti.com/lit/ds/symlink/ina219.pdf
+ *
+ * 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.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/spinlock.h>
+#include <linux/sysfs.h>
+#include <linux/kobject.h>
+#include <linux/hrtimer.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/mutex.h>
+#include <linux/i2c.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/gpio.h>
+#include <linux/device.h>
+#include <linux/sysdev.h>
+#include "linux/ina219.h"
+#include <linux/init.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/hwmon.h>
+
+#define DRIVER_NAME "ina219"
+
+/* INA219 register offsets */
+#define INA219_CONFIG	0
+#define INA219_SHUNT	1
+#define INA219_VOLTAGE	2
+#define INA219_POWER	3
+#define INA219_CURRENT	4
+#define INA219_CAL	5
+
+/*
+	INA219 Sensor defines
+	Config info for ina219s
+	D15   D14  D13  D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
+	rst  BRNG  PG1 PG0  BADC4 .-.BADC1 SADC4 - SADC1 MODE3 - MODE1
+	reset D15
+	bus_range=0 (d13)
+	pga_gain=0  (D12:D11)
+	bus_adc_setting=0x3     (d10:D7) 12-bit w/o oversampling (532uS)
+	shunt_adc_setting=0xb    (D6:D3) 8x oversampling (4.26ms)
+	mode=0x7                 (D2:D0) continuous shunt & bus
+*/
+#define INA219_CONFIG_DATA 0x1df
+#define INA219_RESET 0x8000
+
+struct power_mon_data {
+	s32 voltage;
+	s32 currentInMillis;
+	s32 power;
+};
+
+struct ina219_data {
+	struct device *hwmon_dev;
+	struct i2c_client *client;
+	struct ina219_platform_data *pInfo;
+	struct power_mon_data pm_data;
+	struct mutex mutex;
+};
+
+/* Set non-zero to enable debug prints */
+#define INA219_DEBUG_PRINTS 0
+
+#if INA219_DEBUG_PRINTS
+#define DEBUG_INA219(x) printk x
+#else
+#define DEBUG_INA219(x)
+#endif
+
+static s16 reorder_bytes(s16 a)
+{
+	s16 ret = ((a >> 8) & 0xff) | ((a & 0xff) << 8);
+	return ret;
+}
+
+/* set ina219 to power down mode */
+static s32 power_down_INA219(struct i2c_client *client)
+{
+	s32 retval;
+	retval = i2c_smbus_write_word_data(client, INA219_CONFIG, 0);
+	if (retval < 0)
+		dev_err(&client->dev, "power down failure sts: 0x%x\n", retval);
+	return retval;
+}
+
+
+static s32 show_voltage(struct device *dev,
+			struct device_attribute *attr,
+			char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct ina219_data *data = i2c_get_clientdata(client);
+	s32 retval;
+	s32 voltage_mV;
+
+	/* fill config data */
+	retval = i2c_smbus_write_word_data(client, INA219_CONFIG,
+		reorder_bytes(INA219_CONFIG_DATA));
+	if (retval < 0) {
+		dev_err(dev, "config data write failed sts: 0x%x\n", retval);
+		goto error;
+	}
+
+	/* fill calibration data */
+	retval = i2c_smbus_write_word_data(client, INA219_CAL,
+		reorder_bytes(data->pInfo->calibration_data));
+	if (retval < 0) {
+		dev_err(dev, "calib data write failed sts: 0x%x\n", retval);
+		goto error;
+	}
+
+	/* getting voltage readings in milli volts*/
+	voltage_mV =
+		reorder_bytes(i2c_smbus_read_word_data(client,
+			INA219_VOLTAGE));
+	DEBUG_INA219(("Ina219 voltage reg Value: 0x%x\n", voltage_mV));
+	if (voltage_mV < 0)
+		goto error;
+	voltage_mV = voltage_mV >> 1;
+	DEBUG_INA219(("Ina219 voltage in mv: %d\n", voltage_mV));
+
+	/* set ina219 to power down mode */
+	retval = power_down_INA219(client);
+	if (retval < 0)
+		goto error;
+
+	DEBUG_INA219(("%s volt = %d\n", __func__, voltage_mV));
+	return sprintf(buf, "%d mV\n", voltage_mV);
+error:
+	dev_err(dev, "%s: failed\n", __func__);
+	return retval;
+}
+
+
+static s32 show_power(struct device *dev,
+			struct device_attribute *attr,
+			char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct ina219_data *data = i2c_get_clientdata(client);
+	s32 retval;
+	s32 power_mW;
+	s32 voltage_mV;
+	s32 overflow, conversion;
+
+	/* fill config data */
+	retval = i2c_smbus_write_word_data(client, INA219_CONFIG,
+		reorder_bytes(INA219_CONFIG_DATA));
+	if (retval < 0) {
+		dev_err(dev, "config data write failed sts: 0x%x\n", retval);
+		goto error;
+	}
+
+	/* fill calib data */
+	retval = i2c_smbus_write_word_data(client, INA219_CAL,
+		reorder_bytes(data->pInfo->calibration_data));
+	if (retval < 0) {
+		dev_err(dev, "calibration data write failed sts: 0x%x\n",
+			retval);
+		goto error;
+	}
+
+	/* check if the readings are valid */
+	do {
+		/* read power register to clear conversion bit */
+		retval = reorder_bytes(i2c_smbus_read_word_data(client,
+			INA219_POWER));
+		if (retval < 0) {
+			dev_err(dev, "CNVR bit clearing failure sts: 0x%x\n",
+				retval);
+			goto error;
+		}
+
+		voltage_mV =
+			reorder_bytes(i2c_smbus_read_word_data(client,
+				INA219_VOLTAGE));
+		DEBUG_INA219(("Ina219 voltage reg Value: 0x%x\n", voltage_mV));
+		overflow = voltage_mV & 1;
+		if (overflow) {
+			dev_err(dev, "overflow error\n");
+			return 0;
+		}
+		conversion = (voltage_mV >> 1) & 1;
+		DEBUG_INA219(("\n ina219 CNVR value:%d", conversion));
+	} while (!conversion);
+
+	/* getting power readings in milli watts*/
+	power_mW = reorder_bytes(i2c_smbus_read_word_data(client,
+		INA219_POWER));
+	DEBUG_INA219(("Ina219 power Reg: 0x%x\n", power_mW));
+	power_mW *= data->pInfo->power_lsb;
+	DEBUG_INA219(("Ina219 power Val: %d\n", power_mW));
+	if (power_mW < 0)
+		goto error;
+
+	/* set ina219 to power down mode */
+	retval = power_down_INA219(client);
+	if (retval < 0)
+		goto error;
+
+	DEBUG_INA219(("%s pow = %d\n", __func__, power_mW));
+	return sprintf(buf, "%d mW\n", power_mW);
+error:
+	dev_err(dev, "%s: failed\n", __func__);
+	return retval;
+}
+
+static s32 show_current(struct device *dev,
+			struct device_attribute *attr,
+			char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct ina219_data *data = i2c_get_clientdata(client);
+	s32 retval;
+	s32 current_mA;
+	s32 voltage_mV;
+	s32 overflow, conversion;
+
+	/* fill config data */
+	retval = i2c_smbus_write_word_data(client, INA219_CONFIG,
+		reorder_bytes(INA219_CONFIG_DATA));
+	if (retval < 0) {
+		dev_err(dev, "config data write failed sts: 0x%x\n", retval);
+		goto error;
+	}
+
+	/* fill calib data */
+	retval = i2c_smbus_write_word_data(client, INA219_CAL,
+		reorder_bytes(data->pInfo->calibration_data));
+	if (retval < 0) {
+		dev_err(dev, "calibration data write failed sts: 0x%x\n",
+			retval);
+		goto error;
+	}
+
+	/* check if the readings are valid */
+	do {
+		/* read power register to clear conversion bit */
+		retval = reorder_bytes(i2c_smbus_read_word_data(client,
+			INA219_POWER));
+		if (retval < 0) {
+			dev_err(dev, "CNVR bit clearing failure sts: 0x%x\n",
+				retval);
+			goto error;
+		}
+
+		voltage_mV =
+			reorder_bytes(i2c_smbus_read_word_data(client,
+				INA219_VOLTAGE));
+		DEBUG_INA219(("Ina219 voltage reg Value: 0x%x\n", voltage_mV));
+		overflow = voltage_mV & 1;
+		if (overflow) {
+			dev_err(dev, "overflow error\n");
+			return 0;
+		}
+		conversion = (voltage_mV >> 1) & 1;
+		DEBUG_INA219(("\n ina219 CNVR value:%d", conversion));
+	} while (!conversion);
+
+	/* getting current readings in milli amps*/
+	current_mA = reorder_bytes(i2c_smbus_read_word_data(client,
+		INA219_CURRENT));
+	DEBUG_INA219(("Ina219 current Reg: 0x%x\n", current_mA));
+	if (current_mA < 0)
+		goto error;
+	current_mA =
+		(current_mA * data->pInfo->power_lsb) / data->pInfo->divisor;
+	DEBUG_INA219(("Ina219 current Value: %d\n", current_mA));
+
+	/* set ina219 to power down mode */
+	retval = power_down_INA219(client);
+	if (retval < 0)
+		goto error;
+
+
+	DEBUG_INA219(("%s current = %d\n", __func__, current_mA));
+	return sprintf(buf, "%d mA\n", current_mA);
+error:
+	dev_err(dev, "%s: failed\n", __func__);
+	return retval;
+}
+
+static struct sensor_device_attribute ina219[] = {
+	SENSOR_ATTR(in1_input, S_IRUGO, show_voltage, NULL, 0),
+	SENSOR_ATTR(curr1_input, S_IRUGO, show_current, NULL, 0),
+	SENSOR_ATTR(power1_input, S_IRUGO, show_power, NULL, 0),
+};
+
+static int __devinit ina219_probe(struct i2c_client *client,
+				const struct i2c_device_id *id)
+{
+	struct ina219_data *data;
+	int err;
+	u8 i;
+	data = kzalloc(sizeof(struct ina219_data), GFP_KERNEL);
+	if (!data) {
+		err = -ENOMEM;
+		goto exit;
+	}
+
+	i2c_set_clientdata(client, data);
+	data->pInfo = client->dev.platform_data;
+	mutex_init(&data->mutex);
+	/* reset ina219 */
+	err = i2c_smbus_write_word_data(client, INA219_CONFIG,
+		reorder_bytes(INA219_RESET));
+	if (err < 0) {
+		dev_err(&client->dev, "ina219 reset failure status: 0x%x\n",
+			err);
+		goto exit_free;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(ina219); i++) {
+		err = device_create_file(&client->dev, &ina219[i].dev_attr);
+		if (err) {
+			dev_err(&client->dev, "device_create_file failed.\n");
+			goto exit_free;
+		}
+	}
+
+	data->hwmon_dev = hwmon_device_register(&client->dev);
+	if (IS_ERR(data->hwmon_dev)) {
+		err = PTR_ERR(data->hwmon_dev);
+		goto exit_remove;
+	}
+
+	/* set ina219 to power down mode */
+	err = power_down_INA219(client);
+	if (err < 0)
+		goto exit_remove;
+
+	return 0;
+
+exit_remove:
+	for (i = 0; i < ARRAY_SIZE(ina219); i++)
+		device_remove_file(&client->dev, &ina219[i].dev_attr);
+exit_free:
+	kfree(data);
+exit:
+	return err;
+}
+
+static int __devexit ina219_remove(struct i2c_client *client)
+{
+	u8 i;
+	struct ina219_data *data = i2c_get_clientdata(client);
+	hwmon_device_unregister(data->hwmon_dev);
+	for (i = 0; i < ARRAY_SIZE(ina219); i++)
+		device_remove_file(&client->dev, &ina219[i].dev_attr);
+	kfree(data);
+	return 0;
+}
+
+static const struct i2c_device_id ina219_id[] = {
+	{DRIVER_NAME, 0 },
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, ina219_id);
+
+static struct i2c_driver ina219_driver = {
+	.class		= I2C_CLASS_HWMON,
+	.driver = {
+		.name	= DRIVER_NAME,
+	},
+	.probe		= ina219_probe,
+	.remove		= __devexit_p(ina219_remove),
+	.id_table	= ina219_id,
+};
+
+static int __init ina219_init(void)
+{
+	return i2c_add_driver(&ina219_driver);
+}
+
+static void __exit ina219_exit(void)
+{
+	i2c_del_driver(&ina219_driver);
+}
+
+module_init(ina219_init);
+module_exit(ina219_exit);
+MODULE_LICENSE("GPL");