hwmon: ina230: Add driver for INA230 (/ INA226)

Adds support for current monitoring for battery EDP capping

Change-Id: I85fc1770013ab80b986b3b6d77ffd96e1dc4068f
Signed-off-by: Peter Boonstoppel <pboonstoppel@nvidia.com>
Reviewed-on: http://git-master/r/60560
Reviewed-on: http://git-master/r/69111
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Anshul Jain (SW) <anshulj@nvidia.com>
Tested-by: Anshul Jain (SW) <anshulj@nvidia.com>
Reviewed-by: Dan Willemsen <dwillemsen@nvidia.com>

3 files changed, 570 insertions, 0 deletions

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 0a48528714a8..1f46b8d3a791 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1352,6 +1352,14 @@ config SENSORS_INA219
 	help
 		Support for the TI INA219 power monitor sensor.
 
+config SENSORS_INA230
+	tristate "Texas Instruments INA230 POWER MONITOR SENSOR DRIVER"
+	depends on I2C
+	help
+	  Support for the TI INA230 power monitor sensor.
+	  (also works for TI INA226)
+
+
 if ACPI
 
 comment "ACPI drivers"
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index df607e1d8431..d9797487180d 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -125,6 +125,7 @@ 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-$(CONFIG_SENSORS_INA230)	+= ina230.o
 obj-$(CONFIG_SENSORS_TEGRA_TSENSOR) += tegra-tsensor.o
 
 obj-$(CONFIG_PMBUS)		+= pmbus/
diff --git a/drivers/hwmon/ina230.c b/drivers/hwmon/ina230.c
new file mode 100644
index 000000000000..3591a9463108
--- /dev/null
+++ b/drivers/hwmon/ina230.c
@@ -0,0 +1,561 @@
+/*
+ * ina230.c - driver for TI INA230 current / power monitor sensor
+ * (also compatible with TI INA226)
+ *
+ *
+ * Copyright (c) 2011, NVIDIA Corporation.
+ *
+ * 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.
+ *
+ * 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.
+ *
+ *
+ * The INA230(/INA226) is a sensor chip made by Texas Instruments. It measures
+ * power, voltage and current on a power rail and provides an alert on
+ * over voltage/power
+ * Complete datasheet can be obtained from ti.com
+ *
+ */
+
+#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/platform_data/ina230.h>
+#include <linux/init.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/hwmon.h>
+#include <linux/cpu.h>
+
+
+#define DRIVER_NAME "ina230"
+#define MEASURE_BUS_VOLT 0
+
+/* ina230 (/ ina226)register offsets */
+#define INA230_CONFIG	0
+#define INA230_SHUNT	1
+#define INA230_VOLTAGE	2
+#define INA230_POWER	3
+#define INA230_CURRENT	4
+#define INA230_CAL	5
+#define INA230_MASK	6
+#define INA230_ALERT	7
+
+/*
+Config register for ina230 (/ ina226):
+D15|D14 D13 D12|D11 D10 D09|D08 D07 D06|D05 D04 D03|D02 D01 D00
+rst|-   -   -  |AVG        |Vbus_CT    |Vsh_CT     |MODE
+*/
+#define INA230_RESET		(1 << 15)
+#define INA230_AVG		(0 << 9) /* 0 Averages */
+#define INA230_VBUS_CT		(0 << 6) /* Vbus 140us conversion time */
+#define INA230_VSH_CT		(0 << 3) /* Vshunt 140us conversion time */
+
+#if MEASURE_BUS_VOLT
+#define INA230_CONT_MODE	5	/* Continuous Shunt measurement */
+#define INA230_TRIG_MODE	1	/* Triggered Shunt measurement */
+#else
+#define INA230_CONT_MODE	7	/* Continuous Bus and shunt measure */
+#define INA230_TRIG_MODE	3	/* Triggered Bus and shunt measure */
+#endif
+
+#define INA230_POWER_DOWN	0
+#define INA230_CONT_CONFIG	(INA230_AVG | INA230_VBUS_CT | \
+				 INA230_VSH_CT | INA230_CONT_MODE)
+#define INA230_TRIG_CONFIG	(INA230_AVG | INA230_VBUS_CT | \
+				 INA230_VSH_CT | INA230_TRIG_MODE)
+
+/*
+Mask register for ina230 (/ina 226):
+D15|D14|D13|D12|D11 D10 D09 D08 D07 D06 D05 D04 D03 D02 D01 D00
+SOL|SUL|BOL|BUL|POL|CVR|-   -   -   -   -  |AFF|CVF|OVF|APO|LEN
+*/
+#define INA230_MASK_SOL		(1 << 15)
+#define INA230_MASK_SUL		(1 << 14)
+
+
+struct ina230_data {
+	struct device *hwmon_dev;
+	struct i2c_client *client;
+	struct ina230_platform_data *pdata;
+	struct mutex mutex;
+	bool running;
+	struct notifier_block nb;
+};
+
+
+/* bus voltage resolution: 1.25mv */
+#define busv_register_to_mv(x) (((x) * 5) >> 2)
+
+/* shunt voltage resolution: 2.5uv */
+#define shuntv_register_to_uv(x) (((x) * 5) >> 1)
+#define uv_to_alert_register(x) (((x) << 1) / 5)
+
+
+
+static s32 ensure_enabled_start(struct i2c_client *client)
+{
+	struct ina230_data *data = i2c_get_clientdata(client);
+	int retval;
+
+	if (data->running)
+		return 0;
+
+	retval = i2c_smbus_write_word_data(client, INA230_CONFIG,
+				    __constant_cpu_to_be16(INA230_TRIG_CONFIG));
+	if (retval < 0)
+		dev_err(&client->dev, "config data write failed sts: 0x%x\n",
+			retval);
+
+	return retval;
+}
+
+
+static void ensure_enabled_end(struct i2c_client *client)
+{
+	struct ina230_data *data = i2c_get_clientdata(client);
+	int retval;
+
+	if (data->running)
+		return;
+
+	retval = i2c_smbus_write_word_data(client, INA230_CONFIG,
+				     __constant_cpu_to_be16(INA230_POWER_DOWN));
+	if (retval < 0)
+		dev_err(&client->dev, "power down failure sts: 0x%x\n",
+			retval);
+}
+
+
+static s32 __locked_power_down_ina230(struct i2c_client *client)
+{
+	s32 retval;
+	struct ina230_data *data = i2c_get_clientdata(client);
+
+	if (!data->running)
+		return 0;
+
+	retval = i2c_smbus_write_word_data(client, INA230_MASK, 0);
+	if (retval < 0)
+		dev_err(&client->dev, "mask write failure sts: 0x%x\n",
+			retval);
+
+	retval = i2c_smbus_write_word_data(client, INA230_CONFIG,
+				     __constant_cpu_to_be16(INA230_POWER_DOWN));
+	if (retval < 0)
+		dev_err(&client->dev, "power down failure sts: 0x%x\n",
+			retval);
+
+	data->running = false;
+
+	return retval;
+}
+
+
+static s32 power_down_ina230(struct i2c_client *client)
+{
+	s32 retval;
+	struct ina230_data *data = i2c_get_clientdata(client);
+
+	mutex_lock(&data->mutex);
+	retval = __locked_power_down_ina230(client);
+	mutex_unlock(&data->mutex);
+
+	return retval;
+}
+
+
+static s32 __locked_start_current_mon(struct i2c_client *client)
+{
+	s32 retval;
+	s16 shunt_limit;
+	s16 alert_mask;
+	struct ina230_data *data = i2c_get_clientdata(client);
+
+	if (!data->pdata->current_threshold) {
+		dev_err(&client->dev, "no current threshold specified\n");
+		return -EINVAL;
+	}
+
+	retval = i2c_smbus_write_word_data(client, INA230_CONFIG,
+				    __constant_cpu_to_be16(INA230_CONT_CONFIG));
+	if (retval < 0) {
+		dev_err(&client->dev, "config data write failed sts: 0x%x\n",
+			retval);
+		return retval;
+	}
+
+	shunt_limit = uv_to_alert_register(data->pdata->resistor *
+					   data->pdata->current_threshold);
+
+	retval = i2c_smbus_write_word_data(client, INA230_ALERT,
+					   cpu_to_be16(shunt_limit));
+	if (retval < 0) {
+		dev_err(&client->dev, "alert data write failed sts: 0x%x\n",
+			retval);
+		return retval;
+	}
+
+	alert_mask = shunt_limit >= 0 ? INA230_MASK_SOL : INA230_MASK_SUL;
+	retval = i2c_smbus_write_word_data(client, INA230_MASK,
+					   cpu_to_be16(alert_mask));
+	if (retval < 0) {
+		dev_err(&client->dev, "mask data write failed sts: 0x%x\n",
+			retval);
+		return retval;
+	}
+
+	data->running = true;
+
+	return 0;
+}
+
+
+static void __locked_evaluate_state(struct i2c_client *client)
+{
+	struct ina230_data *data = i2c_get_clientdata(client);
+	int cpus = num_online_cpus();
+
+	if (data->running) {
+		if (cpus < data->pdata->min_cores_online ||
+		    !data->pdata->current_threshold)
+			__locked_power_down_ina230(client);
+	} else {
+		if (cpus >= data->pdata->min_cores_online &&
+		    data->pdata->current_threshold)
+			__locked_start_current_mon(client);
+	}
+}
+
+
+static void evaluate_state(struct i2c_client *client)
+{
+	struct ina230_data *data = i2c_get_clientdata(client);
+
+	mutex_lock(&data->mutex);
+	__locked_evaluate_state(client);
+	mutex_unlock(&data->mutex);
+}
+
+
+static s32 show_rail_name(struct device *dev,
+			  struct device_attribute *attr,
+			  char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct ina230_data *data = i2c_get_clientdata(client);
+	return sprintf(buf, "%s\n", data->pdata->rail_name);
+}
+
+
+static s32 show_current_threshold(struct device *dev,
+				  struct device_attribute *attr,
+				  char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct ina230_data *data = i2c_get_clientdata(client);
+	return sprintf(buf, "%d mA\n", data->pdata->current_threshold);
+}
+
+
+static s32 set_current_threshold(struct device *dev,
+				 struct device_attribute *attr,
+				 const char *buf, size_t count)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct ina230_data *data = i2c_get_clientdata(client);
+	s32 retval;
+
+	mutex_lock(&data->mutex);
+
+	if (strict_strtol(buf, 10, (long *)&(data->pdata->current_threshold))) {
+		retval = -EINVAL;
+		goto out;
+	}
+
+	if (data->pdata->current_threshold) {
+		if (data->running) {
+			/* force restart */
+			retval = __locked_start_current_mon(client);
+		} else {
+			__locked_evaluate_state(client);
+			retval = 0;
+		}
+	} else {
+		retval = __locked_power_down_ina230(client);
+	}
+
+out:
+	mutex_unlock(&data->mutex);
+	if (retval >= 0)
+		return count;
+	return retval;
+}
+
+
+
+
+#if MEASURE_BUS_VOLT
+static s32 show_bus_voltage(struct device *dev,
+			struct device_attribute *attr,
+			char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct ina230_data *data = i2c_get_clientdata(client);
+	s32 voltage_mV;
+	int retval;
+
+	mutex_lock(&data->mutex);
+	retval = ensure_enabled_start(client);
+	if (retval < 0) {
+		mutex_unlock(&data->mutex);
+		return retval;
+	}
+
+	/* getting voltage readings in milli volts*/
+	voltage_mV =
+		(s16)be16_to_cpu(i2c_smbus_read_word_data(client,
+							  INA230_VOLTAGE));
+
+	ensure_enabled_end(client);
+	mutex_unlock(&data->mutex);
+
+	if (voltage_mV < 0) {
+		dev_err(dev, "%s: failed\n", __func__);
+		return -1;
+	}
+
+	voltage_mV = busv_register_to_mv(voltage_mV);
+
+	return sprintf(buf, "%d mV\n", voltage_mV);
+}
+#endif
+
+
+
+
+static s32 show_shunt_voltage(struct device *dev,
+			struct device_attribute *attr,
+			char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct ina230_data *data = i2c_get_clientdata(client);
+	s32 voltage_uV;
+	int retval;
+
+	mutex_lock(&data->mutex);
+	retval = ensure_enabled_start(client);
+	if (retval < 0) {
+		mutex_unlock(&data->mutex);
+		return retval;
+	}
+
+	voltage_uV =
+		(s16)be16_to_cpu(i2c_smbus_read_word_data(client,
+							  INA230_SHUNT));
+
+	ensure_enabled_end(client);
+	mutex_unlock(&data->mutex);
+
+	voltage_uV = shuntv_register_to_uv(voltage_uV);
+
+	return sprintf(buf, "%d uV\n", voltage_uV);
+}
+
+
+static s32 show_current(struct device *dev,
+			struct device_attribute *attr,
+			char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct ina230_data *data = i2c_get_clientdata(client);
+	s32 voltage_uV;
+	s32 current_mA;
+	int retval;
+
+	mutex_lock(&data->mutex);
+	retval = ensure_enabled_start(client);
+	if (retval < 0) {
+		mutex_unlock(&data->mutex);
+		return retval;
+	}
+
+	voltage_uV =
+		(s16)be16_to_cpu(i2c_smbus_read_word_data(client,
+							  INA230_SHUNT));
+
+	ensure_enabled_end(client);
+	mutex_unlock(&data->mutex);
+
+	voltage_uV = shuntv_register_to_uv(voltage_uV);
+	current_mA = voltage_uV / data->pdata->resistor;
+
+	return sprintf(buf, "%d mA\n", current_mA);
+}
+
+
+static int ina230_hotplug_notify(struct notifier_block *nb, unsigned long event,
+				void *hcpu)
+{
+	struct ina230_data *data = container_of(nb, struct ina230_data,
+						nb);
+	struct i2c_client *client = data->client;
+
+	if (event == CPU_ONLINE || event == CPU_DEAD)
+		evaluate_state(client);
+
+	return 0;
+}
+
+
+
+static struct sensor_device_attribute ina230[] = {
+	SENSOR_ATTR(rail_name, S_IRUGO, show_rail_name, NULL, 0),
+	SENSOR_ATTR(current_threshold, S_IWUSR | S_IRUGO,
+		    show_current_threshold, set_current_threshold, 0),
+	SENSOR_ATTR(shuntvolt1_input, S_IRUGO, show_shunt_voltage, NULL, 0),
+	SENSOR_ATTR(current1_input, S_IRUGO, show_current, NULL, 0),
+#if MEASURE_BUS_VOLT
+	SENSOR_ATTR(busvolt1_input, S_IRUGO, show_bus_voltage, NULL, 0),
+#endif
+};
+
+
+static int __devinit ina230_probe(struct i2c_client *client,
+				const struct i2c_device_id *id)
+{
+	struct ina230_data *data;
+	int err;
+	u8 i;
+
+	data = devm_kzalloc(&client->dev, sizeof(struct ina230_data),
+			    GFP_KERNEL);
+	if (!data) {
+		err = -ENOMEM;
+		goto exit;
+	}
+
+	i2c_set_clientdata(client, data);
+	data->pdata = client->dev.platform_data;
+	data->running = false;
+	data->nb.notifier_call = ina230_hotplug_notify;
+	data->client = client;
+	mutex_init(&data->mutex);
+
+	err = i2c_smbus_write_word_data(client, INA230_CONFIG,
+		__constant_cpu_to_be16(INA230_RESET));
+	if (err < 0) {
+		dev_err(&client->dev, "ina230 reset failure status: 0x%x\n",
+			err);
+		goto exit;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(ina230); i++) {
+		err = device_create_file(&client->dev, &ina230[i].dev_attr);
+		if (err) {
+			dev_err(&client->dev, "device_create_file failed.\n");
+			goto exit_remove;
+		}
+	}
+
+	data->hwmon_dev = hwmon_device_register(&client->dev);
+	if (IS_ERR(data->hwmon_dev)) {
+		err = PTR_ERR(data->hwmon_dev);
+		goto exit_remove;
+	}
+
+	register_hotcpu_notifier(&(data->nb));
+
+	evaluate_state(client);
+
+	return 0;
+
+exit_remove:
+	for (i = 0; i < ARRAY_SIZE(ina230); i++)
+		device_remove_file(&client->dev, &ina230[i].dev_attr);
+exit:
+	return err;
+}
+
+
+static int __devexit ina230_remove(struct i2c_client *client)
+{
+	u8 i;
+	struct ina230_data *data = i2c_get_clientdata(client);
+	unregister_hotcpu_notifier(&(data->nb));
+	power_down_ina230(client);
+	hwmon_device_unregister(data->hwmon_dev);
+	for (i = 0; i < ARRAY_SIZE(ina230); i++)
+		device_remove_file(&client->dev, &ina230[i].dev_attr);
+	return 0;
+}
+
+
+static int ina230_suspend(struct i2c_client *client)
+{
+	return power_down_ina230(client);
+}
+
+
+static int ina230_resume(struct i2c_client *client)
+{
+	evaluate_state(client);
+	return 0;
+}
+
+
+static const struct i2c_device_id ina230_id[] = {
+	{DRIVER_NAME, 0 },
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, ina230_id);
+
+
+static struct i2c_driver ina230_driver = {
+	.class		= I2C_CLASS_HWMON,
+	.driver = {
+		.name	= DRIVER_NAME,
+	},
+	.probe		= ina230_probe,
+	.remove		= __devexit_p(ina230_remove),
+	.suspend	= ina230_suspend,
+	.resume		= ina230_resume,
+	.id_table	= ina230_id,
+};
+
+
+static int __init ina230_init(void)
+{
+	return i2c_add_driver(&ina230_driver);
+}
+
+
+static void __exit ina230_exit(void)
+{
+	i2c_del_driver(&ina230_driver);
+}
+
+
+module_init(ina230_init);
+module_exit(ina230_exit);
+MODULE_LICENSE("GPL");