v4.19.13 snapshot.
diff --git a/drivers/hwmon/powr1220.c b/drivers/hwmon/powr1220.c
new file mode 100644
index 0000000..3014e4a
--- /dev/null
+++ b/drivers/hwmon/powr1220.c
@@ -0,0 +1,391 @@
+/*
+ * powr1220.c - Driver for the Lattice POWR1220 programmable power supply
+ * and monitor. Users can read all ADC inputs along with their labels
+ * using the sysfs nodes.
+ *
+ * Copyright (c) 2014 Echo360 http://www.echo360.com
+ * Scott Kanowitz <skanowitz@echo360.com> <scott.kanowitz@gmail.com>
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/jiffies.h>
+#include <linux/i2c.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/delay.h>
+
+#define ADC_STEP_MV			2
+#define ADC_MAX_LOW_MEASUREMENT_MV	2000
+
+enum powr1220_regs {
+	VMON_STATUS0,
+	VMON_STATUS1,
+	VMON_STATUS2,
+	OUTPUT_STATUS0,
+	OUTPUT_STATUS1,
+	OUTPUT_STATUS2,
+	INPUT_STATUS,
+	ADC_VALUE_LOW,
+	ADC_VALUE_HIGH,
+	ADC_MUX,
+	UES_BYTE0,
+	UES_BYTE1,
+	UES_BYTE2,
+	UES_BYTE3,
+	GP_OUTPUT1,
+	GP_OUTPUT2,
+	GP_OUTPUT3,
+	INPUT_VALUE,
+	RESET,
+	TRIM1_TRIM,
+	TRIM2_TRIM,
+	TRIM3_TRIM,
+	TRIM4_TRIM,
+	TRIM5_TRIM,
+	TRIM6_TRIM,
+	TRIM7_TRIM,
+	TRIM8_TRIM,
+	MAX_POWR1220_REGS
+};
+
+enum powr1220_adc_values {
+	VMON1,
+	VMON2,
+	VMON3,
+	VMON4,
+	VMON5,
+	VMON6,
+	VMON7,
+	VMON8,
+	VMON9,
+	VMON10,
+	VMON11,
+	VMON12,
+	VCCA,
+	VCCINP,
+	MAX_POWR1220_ADC_VALUES
+};
+
+struct powr1220_data {
+	struct i2c_client *client;
+	struct mutex update_lock;
+	bool adc_valid[MAX_POWR1220_ADC_VALUES];
+	 /* the next value is in jiffies */
+	unsigned long adc_last_updated[MAX_POWR1220_ADC_VALUES];
+
+	/* values */
+	int adc_maxes[MAX_POWR1220_ADC_VALUES];
+	int adc_values[MAX_POWR1220_ADC_VALUES];
+};
+
+static const char * const input_names[] = {
+	[VMON1]    = "vmon1",
+	[VMON2]    = "vmon2",
+	[VMON3]    = "vmon3",
+	[VMON4]    = "vmon4",
+	[VMON5]    = "vmon5",
+	[VMON6]    = "vmon6",
+	[VMON7]    = "vmon7",
+	[VMON8]    = "vmon8",
+	[VMON9]    = "vmon9",
+	[VMON10]   = "vmon10",
+	[VMON11]   = "vmon11",
+	[VMON12]   = "vmon12",
+	[VCCA]     = "vcca",
+	[VCCINP]   = "vccinp",
+};
+
+/* Reads the specified ADC channel */
+static int powr1220_read_adc(struct device *dev, int ch_num)
+{
+	struct powr1220_data *data = dev_get_drvdata(dev);
+	int reading;
+	int result;
+	int adc_range = 0;
+
+	mutex_lock(&data->update_lock);
+
+	if (time_after(jiffies, data->adc_last_updated[ch_num] + HZ) ||
+			!data->adc_valid[ch_num]) {
+		/*
+		 * figure out if we need to use the attenuator for
+		 * high inputs or inputs that we don't yet have a measurement
+		 * for. We dynamically set the attenuator depending on the
+		 * max reading.
+		 */
+		if (data->adc_maxes[ch_num] > ADC_MAX_LOW_MEASUREMENT_MV ||
+				data->adc_maxes[ch_num] == 0)
+			adc_range = 1 << 4;
+
+		/* set the attenuator and mux */
+		result = i2c_smbus_write_byte_data(data->client, ADC_MUX,
+				adc_range | ch_num);
+		if (result)
+			goto exit;
+
+		/*
+		 * wait at least Tconvert time (200 us) for the
+		 * conversion to complete
+		 */
+		udelay(200);
+
+		/* get the ADC reading */
+		result = i2c_smbus_read_byte_data(data->client, ADC_VALUE_LOW);
+		if (result < 0)
+			goto exit;
+
+		reading = result >> 4;
+
+		/* get the upper half of the reading */
+		result = i2c_smbus_read_byte_data(data->client, ADC_VALUE_HIGH);
+		if (result < 0)
+			goto exit;
+
+		reading |= result << 4;
+
+		/* now convert the reading to a voltage */
+		reading *= ADC_STEP_MV;
+		data->adc_values[ch_num] = reading;
+		data->adc_valid[ch_num] = true;
+		data->adc_last_updated[ch_num] = jiffies;
+		result = reading;
+
+		if (reading > data->adc_maxes[ch_num])
+			data->adc_maxes[ch_num] = reading;
+	} else {
+		result = data->adc_values[ch_num];
+	}
+
+exit:
+	mutex_unlock(&data->update_lock);
+
+	return result;
+}
+
+/* Shows the voltage associated with the specified ADC channel */
+static ssize_t powr1220_show_voltage(struct device *dev,
+	struct device_attribute *dev_attr, char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
+	int adc_val = powr1220_read_adc(dev, attr->index);
+
+	if (adc_val < 0)
+		return adc_val;
+
+	return sprintf(buf, "%d\n", adc_val);
+}
+
+/* Shows the maximum setting associated with the specified ADC channel */
+static ssize_t powr1220_show_max(struct device *dev,
+	struct device_attribute *dev_attr, char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
+	struct powr1220_data *data = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%d\n", data->adc_maxes[attr->index]);
+}
+
+/* Shows the label associated with the specified ADC channel */
+static ssize_t powr1220_show_label(struct device *dev,
+	struct device_attribute *dev_attr, char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
+
+	return sprintf(buf, "%s\n", input_names[attr->index]);
+}
+
+static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, powr1220_show_voltage, NULL,
+	VMON1);
+static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, powr1220_show_voltage, NULL,
+	VMON2);
+static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, powr1220_show_voltage, NULL,
+	VMON3);
+static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, powr1220_show_voltage, NULL,
+	VMON4);
+static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, powr1220_show_voltage, NULL,
+	VMON5);
+static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, powr1220_show_voltage, NULL,
+	VMON6);
+static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, powr1220_show_voltage, NULL,
+	VMON7);
+static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, powr1220_show_voltage, NULL,
+	VMON8);
+static SENSOR_DEVICE_ATTR(in8_input, S_IRUGO, powr1220_show_voltage, NULL,
+	VMON9);
+static SENSOR_DEVICE_ATTR(in9_input, S_IRUGO, powr1220_show_voltage, NULL,
+	VMON10);
+static SENSOR_DEVICE_ATTR(in10_input, S_IRUGO, powr1220_show_voltage, NULL,
+	VMON11);
+static SENSOR_DEVICE_ATTR(in11_input, S_IRUGO, powr1220_show_voltage, NULL,
+	VMON12);
+static SENSOR_DEVICE_ATTR(in12_input, S_IRUGO, powr1220_show_voltage, NULL,
+	VCCA);
+static SENSOR_DEVICE_ATTR(in13_input, S_IRUGO, powr1220_show_voltage, NULL,
+	VCCINP);
+
+static SENSOR_DEVICE_ATTR(in0_highest, S_IRUGO, powr1220_show_max, NULL,
+	VMON1);
+static SENSOR_DEVICE_ATTR(in1_highest, S_IRUGO, powr1220_show_max, NULL,
+	VMON2);
+static SENSOR_DEVICE_ATTR(in2_highest, S_IRUGO, powr1220_show_max, NULL,
+	VMON3);
+static SENSOR_DEVICE_ATTR(in3_highest, S_IRUGO, powr1220_show_max, NULL,
+	VMON4);
+static SENSOR_DEVICE_ATTR(in4_highest, S_IRUGO, powr1220_show_max, NULL,
+	VMON5);
+static SENSOR_DEVICE_ATTR(in5_highest, S_IRUGO, powr1220_show_max, NULL,
+	VMON6);
+static SENSOR_DEVICE_ATTR(in6_highest, S_IRUGO, powr1220_show_max, NULL,
+	VMON7);
+static SENSOR_DEVICE_ATTR(in7_highest, S_IRUGO, powr1220_show_max, NULL,
+	VMON8);
+static SENSOR_DEVICE_ATTR(in8_highest, S_IRUGO, powr1220_show_max, NULL,
+	VMON9);
+static SENSOR_DEVICE_ATTR(in9_highest, S_IRUGO, powr1220_show_max, NULL,
+	VMON10);
+static SENSOR_DEVICE_ATTR(in10_highest, S_IRUGO, powr1220_show_max, NULL,
+	VMON11);
+static SENSOR_DEVICE_ATTR(in11_highest, S_IRUGO, powr1220_show_max, NULL,
+	VMON12);
+static SENSOR_DEVICE_ATTR(in12_highest, S_IRUGO, powr1220_show_max, NULL,
+	VCCA);
+static SENSOR_DEVICE_ATTR(in13_highest, S_IRUGO, powr1220_show_max, NULL,
+	VCCINP);
+
+static SENSOR_DEVICE_ATTR(in0_label, S_IRUGO, powr1220_show_label, NULL,
+	VMON1);
+static SENSOR_DEVICE_ATTR(in1_label, S_IRUGO, powr1220_show_label, NULL,
+	VMON2);
+static SENSOR_DEVICE_ATTR(in2_label, S_IRUGO, powr1220_show_label, NULL,
+	VMON3);
+static SENSOR_DEVICE_ATTR(in3_label, S_IRUGO, powr1220_show_label, NULL,
+	VMON4);
+static SENSOR_DEVICE_ATTR(in4_label, S_IRUGO, powr1220_show_label, NULL,
+	VMON5);
+static SENSOR_DEVICE_ATTR(in5_label, S_IRUGO, powr1220_show_label, NULL,
+	VMON6);
+static SENSOR_DEVICE_ATTR(in6_label, S_IRUGO, powr1220_show_label, NULL,
+	VMON7);
+static SENSOR_DEVICE_ATTR(in7_label, S_IRUGO, powr1220_show_label, NULL,
+	VMON8);
+static SENSOR_DEVICE_ATTR(in8_label, S_IRUGO, powr1220_show_label, NULL,
+	VMON9);
+static SENSOR_DEVICE_ATTR(in9_label, S_IRUGO, powr1220_show_label, NULL,
+	VMON10);
+static SENSOR_DEVICE_ATTR(in10_label, S_IRUGO, powr1220_show_label, NULL,
+	VMON11);
+static SENSOR_DEVICE_ATTR(in11_label, S_IRUGO, powr1220_show_label, NULL,
+	VMON12);
+static SENSOR_DEVICE_ATTR(in12_label, S_IRUGO, powr1220_show_label, NULL,
+	VCCA);
+static SENSOR_DEVICE_ATTR(in13_label, S_IRUGO, powr1220_show_label, NULL,
+	VCCINP);
+
+static struct attribute *powr1220_attrs[] = {
+	&sensor_dev_attr_in0_input.dev_attr.attr,
+	&sensor_dev_attr_in1_input.dev_attr.attr,
+	&sensor_dev_attr_in2_input.dev_attr.attr,
+	&sensor_dev_attr_in3_input.dev_attr.attr,
+	&sensor_dev_attr_in4_input.dev_attr.attr,
+	&sensor_dev_attr_in5_input.dev_attr.attr,
+	&sensor_dev_attr_in6_input.dev_attr.attr,
+	&sensor_dev_attr_in7_input.dev_attr.attr,
+	&sensor_dev_attr_in8_input.dev_attr.attr,
+	&sensor_dev_attr_in9_input.dev_attr.attr,
+	&sensor_dev_attr_in10_input.dev_attr.attr,
+	&sensor_dev_attr_in11_input.dev_attr.attr,
+	&sensor_dev_attr_in12_input.dev_attr.attr,
+	&sensor_dev_attr_in13_input.dev_attr.attr,
+
+	&sensor_dev_attr_in0_highest.dev_attr.attr,
+	&sensor_dev_attr_in1_highest.dev_attr.attr,
+	&sensor_dev_attr_in2_highest.dev_attr.attr,
+	&sensor_dev_attr_in3_highest.dev_attr.attr,
+	&sensor_dev_attr_in4_highest.dev_attr.attr,
+	&sensor_dev_attr_in5_highest.dev_attr.attr,
+	&sensor_dev_attr_in6_highest.dev_attr.attr,
+	&sensor_dev_attr_in7_highest.dev_attr.attr,
+	&sensor_dev_attr_in8_highest.dev_attr.attr,
+	&sensor_dev_attr_in9_highest.dev_attr.attr,
+	&sensor_dev_attr_in10_highest.dev_attr.attr,
+	&sensor_dev_attr_in11_highest.dev_attr.attr,
+	&sensor_dev_attr_in12_highest.dev_attr.attr,
+	&sensor_dev_attr_in13_highest.dev_attr.attr,
+
+	&sensor_dev_attr_in0_label.dev_attr.attr,
+	&sensor_dev_attr_in1_label.dev_attr.attr,
+	&sensor_dev_attr_in2_label.dev_attr.attr,
+	&sensor_dev_attr_in3_label.dev_attr.attr,
+	&sensor_dev_attr_in4_label.dev_attr.attr,
+	&sensor_dev_attr_in5_label.dev_attr.attr,
+	&sensor_dev_attr_in6_label.dev_attr.attr,
+	&sensor_dev_attr_in7_label.dev_attr.attr,
+	&sensor_dev_attr_in8_label.dev_attr.attr,
+	&sensor_dev_attr_in9_label.dev_attr.attr,
+	&sensor_dev_attr_in10_label.dev_attr.attr,
+	&sensor_dev_attr_in11_label.dev_attr.attr,
+	&sensor_dev_attr_in12_label.dev_attr.attr,
+	&sensor_dev_attr_in13_label.dev_attr.attr,
+
+	NULL
+};
+
+ATTRIBUTE_GROUPS(powr1220);
+
+static int powr1220_probe(struct i2c_client *client,
+		const struct i2c_device_id *id)
+{
+	struct powr1220_data *data;
+	struct device *hwmon_dev;
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
+		return -ENODEV;
+
+	data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	mutex_init(&data->update_lock);
+	data->client = client;
+
+	hwmon_dev = devm_hwmon_device_register_with_groups(&client->dev,
+			client->name, data, powr1220_groups);
+
+	return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+static const struct i2c_device_id powr1220_ids[] = {
+	{ "powr1220", 0, },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(i2c, powr1220_ids);
+
+static struct i2c_driver powr1220_driver = {
+	.class		= I2C_CLASS_HWMON,
+	.driver = {
+		.name	= "powr1220",
+	},
+	.probe		= powr1220_probe,
+	.id_table	= powr1220_ids,
+};
+
+module_i2c_driver(powr1220_driver);
+
+MODULE_AUTHOR("Scott Kanowitz");
+MODULE_DESCRIPTION("POWR1220 driver");
+MODULE_LICENSE("GPL");