292 lines
		
	
	
		
			7.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			292 lines
		
	
	
		
			7.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Driver for Linear Technology LTC2990 power monitor
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|  *
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|  * Copyright (C) 2014 Topic Embedded Products
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|  * Author: Mike Looijmans <mike.looijmans@topic.nl>
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|  *
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|  * License: GPLv2
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|  */
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| 
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| #include <linux/bitops.h>
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| #include <linux/err.h>
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| #include <linux/hwmon.h>
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| #include <linux/hwmon-sysfs.h>
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| #include <linux/i2c.h>
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| #include <linux/kernel.h>
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| #include <linux/module.h>
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| #include <linux/of.h>
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| 
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| #define LTC2990_STATUS	0x00
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| #define LTC2990_CONTROL	0x01
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| #define LTC2990_TRIGGER	0x02
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| #define LTC2990_TINT_MSB	0x04
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| #define LTC2990_V1_MSB	0x06
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| #define LTC2990_V2_MSB	0x08
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| #define LTC2990_V3_MSB	0x0A
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| #define LTC2990_V4_MSB	0x0C
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| #define LTC2990_VCC_MSB	0x0E
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| 
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| #define LTC2990_IN0	BIT(0)
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| #define LTC2990_IN1	BIT(1)
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| #define LTC2990_IN2	BIT(2)
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| #define LTC2990_IN3	BIT(3)
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| #define LTC2990_IN4	BIT(4)
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| #define LTC2990_CURR1	BIT(5)
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| #define LTC2990_CURR2	BIT(6)
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| #define LTC2990_TEMP1	BIT(7)
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| #define LTC2990_TEMP2	BIT(8)
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| #define LTC2990_TEMP3	BIT(9)
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| #define LTC2990_NONE	0
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| #define LTC2990_ALL	GENMASK(9, 0)
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| 
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| #define LTC2990_MODE0_SHIFT	0
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| #define LTC2990_MODE0_MASK	GENMASK(2, 0)
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| #define LTC2990_MODE1_SHIFT	3
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| #define LTC2990_MODE1_MASK	GENMASK(1, 0)
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| 
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| /* Enabled measurements for mode bits 2..0 */
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| static const int ltc2990_attrs_ena_0[] = {
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| 	LTC2990_IN1 | LTC2990_IN2 | LTC2990_TEMP3,
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| 	LTC2990_CURR1 | LTC2990_TEMP3,
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| 	LTC2990_CURR1 | LTC2990_IN3 | LTC2990_IN4,
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| 	LTC2990_TEMP2 | LTC2990_IN3 | LTC2990_IN4,
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| 	LTC2990_TEMP2 | LTC2990_CURR2,
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| 	LTC2990_TEMP2 | LTC2990_TEMP3,
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| 	LTC2990_CURR1 | LTC2990_CURR2,
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| 	LTC2990_IN1 | LTC2990_IN2 | LTC2990_IN3 | LTC2990_IN4
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| };
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| 
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| /* Enabled measurements for mode bits 4..3 */
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| static const int ltc2990_attrs_ena_1[] = {
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| 	LTC2990_NONE,
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| 	LTC2990_TEMP2 | LTC2990_IN1 | LTC2990_CURR1,
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| 	LTC2990_TEMP3 | LTC2990_IN3 | LTC2990_CURR2,
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| 	LTC2990_ALL
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| };
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| 
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| struct ltc2990_data {
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| 	struct i2c_client *i2c;
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| 	u32 mode[2];
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| };
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| 
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| /* Return the converted value from the given register in uV or mC */
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| static int ltc2990_get_value(struct i2c_client *i2c, int index, int *result)
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| {
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| 	int val;
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| 	u8 reg;
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| 
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| 	switch (index) {
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| 	case LTC2990_IN0:
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| 		reg = LTC2990_VCC_MSB;
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| 		break;
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| 	case LTC2990_IN1:
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| 	case LTC2990_CURR1:
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| 	case LTC2990_TEMP2:
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| 		reg = LTC2990_V1_MSB;
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| 		break;
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| 	case LTC2990_IN2:
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| 		reg = LTC2990_V2_MSB;
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| 		break;
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| 	case LTC2990_IN3:
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| 	case LTC2990_CURR2:
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| 	case LTC2990_TEMP3:
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| 		reg = LTC2990_V3_MSB;
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| 		break;
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| 	case LTC2990_IN4:
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| 		reg = LTC2990_V4_MSB;
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| 		break;
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| 	case LTC2990_TEMP1:
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| 		reg = LTC2990_TINT_MSB;
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| 		break;
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| 	default:
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| 		return -EINVAL;
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| 	}
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| 
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| 	val = i2c_smbus_read_word_swapped(i2c, reg);
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| 	if (unlikely(val < 0))
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| 		return val;
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| 
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| 	switch (index) {
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| 	case LTC2990_TEMP1:
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| 	case LTC2990_TEMP2:
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| 	case LTC2990_TEMP3:
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| 		/* temp, 0.0625 degrees/LSB */
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| 		*result = sign_extend32(val, 12) * 1000 / 16;
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| 		break;
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| 	case LTC2990_CURR1:
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| 	case LTC2990_CURR2:
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| 		 /* Vx-Vy, 19.42uV/LSB */
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| 		*result = sign_extend32(val, 14) * 1942 / 100;
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| 		break;
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| 	case LTC2990_IN0:
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| 		/* Vcc, 305.18uV/LSB, 2.5V offset */
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| 		*result = sign_extend32(val, 14) * 30518 / (100 * 1000) + 2500;
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| 		break;
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| 	case LTC2990_IN1:
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| 	case LTC2990_IN2:
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| 	case LTC2990_IN3:
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| 	case LTC2990_IN4:
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| 		/* Vx, 305.18uV/LSB */
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| 		*result = sign_extend32(val, 14) * 30518 / (100 * 1000);
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| 		break;
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| 	default:
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| 		return -EINVAL; /* won't happen, keep compiler happy */
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| 	}
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| 
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| 	return 0;
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| }
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| 
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| static ssize_t ltc2990_show_value(struct device *dev,
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| 				  struct device_attribute *da, char *buf)
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| {
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| 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
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| 	struct ltc2990_data *data = dev_get_drvdata(dev);
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| 	int value;
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| 	int ret;
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| 
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| 	ret = ltc2990_get_value(data->i2c, attr->index, &value);
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| 	if (unlikely(ret < 0))
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| 		return ret;
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| 
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| 	return snprintf(buf, PAGE_SIZE, "%d\n", value);
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| }
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| 
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| static umode_t ltc2990_attrs_visible(struct kobject *kobj,
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| 				     struct attribute *a, int n)
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| {
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| 	struct device *dev = container_of(kobj, struct device, kobj);
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| 	struct ltc2990_data *data = dev_get_drvdata(dev);
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| 	struct device_attribute *da =
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| 			container_of(a, struct device_attribute, attr);
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| 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
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| 
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| 	int attrs_mask = LTC2990_IN0 | LTC2990_TEMP1 |
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| 			 (ltc2990_attrs_ena_0[data->mode[0]] &
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| 			  ltc2990_attrs_ena_1[data->mode[1]]);
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| 
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| 	if (attr->index & attrs_mask)
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| 		return a->mode;
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| 
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| 	return 0;
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| }
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| 
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| static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, ltc2990_show_value, NULL,
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| 			  LTC2990_TEMP1);
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| static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, ltc2990_show_value, NULL,
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| 			  LTC2990_TEMP2);
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| static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, ltc2990_show_value, NULL,
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| 			  LTC2990_TEMP3);
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| static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, ltc2990_show_value, NULL,
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| 			  LTC2990_CURR1);
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| static SENSOR_DEVICE_ATTR(curr2_input, S_IRUGO, ltc2990_show_value, NULL,
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| 			  LTC2990_CURR2);
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| static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, ltc2990_show_value, NULL,
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| 			  LTC2990_IN0);
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| static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, ltc2990_show_value, NULL,
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| 			  LTC2990_IN1);
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| static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, ltc2990_show_value, NULL,
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| 			  LTC2990_IN2);
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| static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, ltc2990_show_value, NULL,
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| 			  LTC2990_IN3);
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| static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, ltc2990_show_value, NULL,
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| 			  LTC2990_IN4);
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| 
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| static struct attribute *ltc2990_attrs[] = {
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| 	&sensor_dev_attr_temp1_input.dev_attr.attr,
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| 	&sensor_dev_attr_temp2_input.dev_attr.attr,
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| 	&sensor_dev_attr_temp3_input.dev_attr.attr,
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| 	&sensor_dev_attr_curr1_input.dev_attr.attr,
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| 	&sensor_dev_attr_curr2_input.dev_attr.attr,
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| 	&sensor_dev_attr_in0_input.dev_attr.attr,
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| 	&sensor_dev_attr_in1_input.dev_attr.attr,
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| 	&sensor_dev_attr_in2_input.dev_attr.attr,
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| 	&sensor_dev_attr_in3_input.dev_attr.attr,
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| 	&sensor_dev_attr_in4_input.dev_attr.attr,
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| 	NULL,
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| };
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| 
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| static const struct attribute_group ltc2990_group = {
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| 	.attrs = ltc2990_attrs,
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| 	.is_visible = ltc2990_attrs_visible,
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| };
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| __ATTRIBUTE_GROUPS(ltc2990);
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| 
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| static int ltc2990_i2c_probe(struct i2c_client *i2c,
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| 			     const struct i2c_device_id *id)
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| {
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| 	int ret;
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| 	struct device *hwmon_dev;
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| 	struct ltc2990_data *data;
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| 	struct device_node *of_node = i2c->dev.of_node;
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| 
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| 	if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_SMBUS_BYTE_DATA |
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| 				     I2C_FUNC_SMBUS_WORD_DATA))
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| 		return -ENODEV;
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| 
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| 	data = devm_kzalloc(&i2c->dev, sizeof(struct ltc2990_data), GFP_KERNEL);
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| 	if (unlikely(!data))
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| 		return -ENOMEM;
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| 
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| 	data->i2c = i2c;
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| 
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| 	if (of_node) {
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| 		ret = of_property_read_u32_array(of_node, "lltc,meas-mode",
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| 						 data->mode, 2);
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| 		if (ret < 0)
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| 			return ret;
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| 
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| 		if (data->mode[0] & ~LTC2990_MODE0_MASK ||
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| 		    data->mode[1] & ~LTC2990_MODE1_MASK)
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| 			return -EINVAL;
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| 	} else {
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| 		ret = i2c_smbus_read_byte_data(i2c, LTC2990_CONTROL);
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| 		if (ret < 0)
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| 			return ret;
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| 
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| 		data->mode[0] = ret >> LTC2990_MODE0_SHIFT & LTC2990_MODE0_MASK;
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| 		data->mode[1] = ret >> LTC2990_MODE1_SHIFT & LTC2990_MODE1_MASK;
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| 	}
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| 
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| 	/* Setup continuous mode */
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| 	ret = i2c_smbus_write_byte_data(i2c, LTC2990_CONTROL,
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| 					data->mode[0] << LTC2990_MODE0_SHIFT |
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| 					data->mode[1] << LTC2990_MODE1_SHIFT);
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| 	if (ret < 0) {
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| 		dev_err(&i2c->dev, "Error: Failed to set control mode.\n");
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| 		return ret;
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| 	}
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| 	/* Trigger once to start continuous conversion */
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| 	ret = i2c_smbus_write_byte_data(i2c, LTC2990_TRIGGER, 1);
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| 	if (ret < 0) {
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| 		dev_err(&i2c->dev, "Error: Failed to start acquisition.\n");
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| 		return ret;
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| 	}
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| 
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| 	hwmon_dev = devm_hwmon_device_register_with_groups(&i2c->dev,
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| 							   i2c->name,
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| 							   data,
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| 							   ltc2990_groups);
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| 
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| 	return PTR_ERR_OR_ZERO(hwmon_dev);
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| }
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| 
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| static const struct i2c_device_id ltc2990_i2c_id[] = {
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| 	{ "ltc2990", 0 },
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| 	{}
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| };
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| MODULE_DEVICE_TABLE(i2c, ltc2990_i2c_id);
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| 
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| static struct i2c_driver ltc2990_i2c_driver = {
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| 	.driver = {
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| 		.name = "ltc2990",
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| 	},
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| 	.probe    = ltc2990_i2c_probe,
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| 	.id_table = ltc2990_i2c_id,
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| };
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| 
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| module_i2c_driver(ltc2990_i2c_driver);
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| 
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| MODULE_DESCRIPTION("LTC2990 Sensor Driver");
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| MODULE_AUTHOR("Topic Embedded Products");
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| MODULE_LICENSE("GPL v2");
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