499 lines
14 KiB
C
499 lines
14 KiB
C
/*
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* Driver for Linear Technology LTC2945 I2C Power Monitor
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*
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* Copyright (c) 2014 Guenter Roeck
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/err.h>
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#include <linux/slab.h>
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#include <linux/i2c.h>
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#include <linux/hwmon.h>
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#include <linux/hwmon-sysfs.h>
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#include <linux/jiffies.h>
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#include <linux/regmap.h>
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/* chip registers */
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#define LTC2945_CONTROL 0x00
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#define LTC2945_ALERT 0x01
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#define LTC2945_STATUS 0x02
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#define LTC2945_FAULT 0x03
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#define LTC2945_POWER_H 0x05
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#define LTC2945_MAX_POWER_H 0x08
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#define LTC2945_MIN_POWER_H 0x0b
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#define LTC2945_MAX_POWER_THRES_H 0x0e
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#define LTC2945_MIN_POWER_THRES_H 0x11
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#define LTC2945_SENSE_H 0x14
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#define LTC2945_MAX_SENSE_H 0x16
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#define LTC2945_MIN_SENSE_H 0x18
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#define LTC2945_MAX_SENSE_THRES_H 0x1a
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#define LTC2945_MIN_SENSE_THRES_H 0x1c
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#define LTC2945_VIN_H 0x1e
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#define LTC2945_MAX_VIN_H 0x20
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#define LTC2945_MIN_VIN_H 0x22
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#define LTC2945_MAX_VIN_THRES_H 0x24
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#define LTC2945_MIN_VIN_THRES_H 0x26
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#define LTC2945_ADIN_H 0x28
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#define LTC2945_MAX_ADIN_H 0x2a
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#define LTC2945_MIN_ADIN_H 0x2c
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#define LTC2945_MAX_ADIN_THRES_H 0x2e
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#define LTC2945_MIN_ADIN_THRES_H 0x30
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#define LTC2945_MIN_ADIN_THRES_L 0x31
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/* Fault register bits */
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#define FAULT_ADIN_UV (1 << 0)
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#define FAULT_ADIN_OV (1 << 1)
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#define FAULT_VIN_UV (1 << 2)
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#define FAULT_VIN_OV (1 << 3)
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#define FAULT_SENSE_UV (1 << 4)
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#define FAULT_SENSE_OV (1 << 5)
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#define FAULT_POWER_UV (1 << 6)
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#define FAULT_POWER_OV (1 << 7)
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/* Control register bits */
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#define CONTROL_MULT_SELECT (1 << 0)
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#define CONTROL_TEST_MODE (1 << 4)
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static inline bool is_power_reg(u8 reg)
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{
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return reg < LTC2945_SENSE_H;
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}
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/* Return the value from the given register in uW, mV, or mA */
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static long long ltc2945_reg_to_val(struct device *dev, u8 reg)
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{
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struct regmap *regmap = dev_get_drvdata(dev);
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unsigned int control;
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u8 buf[3];
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long long val;
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int ret;
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ret = regmap_bulk_read(regmap, reg, buf,
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is_power_reg(reg) ? 3 : 2);
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if (ret < 0)
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return ret;
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if (is_power_reg(reg)) {
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/* power */
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val = (buf[0] << 16) + (buf[1] << 8) + buf[2];
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} else {
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/* current, voltage */
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val = (buf[0] << 4) + (buf[1] >> 4);
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}
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switch (reg) {
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case LTC2945_POWER_H:
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case LTC2945_MAX_POWER_H:
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case LTC2945_MIN_POWER_H:
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case LTC2945_MAX_POWER_THRES_H:
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case LTC2945_MIN_POWER_THRES_H:
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/*
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* Convert to uW by assuming current is measured with
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* an 1mOhm sense resistor, similar to current
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* measurements.
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* Control register bit 0 selects if voltage at SENSE+/VDD
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* or voltage at ADIN is used to measure power.
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*/
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ret = regmap_read(regmap, LTC2945_CONTROL, &control);
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if (ret < 0)
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return ret;
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if (control & CONTROL_MULT_SELECT) {
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/* 25 mV * 25 uV = 0.625 uV resolution. */
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val *= 625LL;
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} else {
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/* 0.5 mV * 25 uV = 0.0125 uV resolution. */
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val = (val * 25LL) >> 1;
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}
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break;
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case LTC2945_VIN_H:
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case LTC2945_MAX_VIN_H:
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case LTC2945_MIN_VIN_H:
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case LTC2945_MAX_VIN_THRES_H:
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case LTC2945_MIN_VIN_THRES_H:
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/* 25 mV resolution. Convert to mV. */
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val *= 25;
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break;
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case LTC2945_ADIN_H:
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case LTC2945_MAX_ADIN_H:
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case LTC2945_MIN_ADIN_THRES_H:
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case LTC2945_MAX_ADIN_THRES_H:
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case LTC2945_MIN_ADIN_H:
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/* 0.5mV resolution. Convert to mV. */
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val = val >> 1;
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break;
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case LTC2945_SENSE_H:
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case LTC2945_MAX_SENSE_H:
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case LTC2945_MIN_SENSE_H:
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case LTC2945_MAX_SENSE_THRES_H:
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case LTC2945_MIN_SENSE_THRES_H:
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/*
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* 25 uV resolution. Convert to current as measured with
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* an 1 mOhm sense resistor, in mA. If a different sense
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* resistor is installed, calculate the actual current by
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* dividing the reported current by the sense resistor value
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* in mOhm.
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*/
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val *= 25;
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break;
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default:
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return -EINVAL;
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}
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return val;
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}
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static int ltc2945_val_to_reg(struct device *dev, u8 reg,
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unsigned long val)
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{
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struct regmap *regmap = dev_get_drvdata(dev);
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unsigned int control;
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int ret;
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switch (reg) {
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case LTC2945_POWER_H:
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case LTC2945_MAX_POWER_H:
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case LTC2945_MIN_POWER_H:
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case LTC2945_MAX_POWER_THRES_H:
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case LTC2945_MIN_POWER_THRES_H:
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/*
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* Convert to register value by assuming current is measured
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* with an 1mOhm sense resistor, similar to current
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* measurements.
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* Control register bit 0 selects if voltage at SENSE+/VDD
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* or voltage at ADIN is used to measure power, which in turn
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* determines register calculations.
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*/
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ret = regmap_read(regmap, LTC2945_CONTROL, &control);
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if (ret < 0)
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return ret;
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if (control & CONTROL_MULT_SELECT) {
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/* 25 mV * 25 uV = 0.625 uV resolution. */
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val = DIV_ROUND_CLOSEST(val, 625);
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} else {
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/*
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* 0.5 mV * 25 uV = 0.0125 uV resolution.
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* Divide first to avoid overflow;
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* accept loss of accuracy.
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*/
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val = DIV_ROUND_CLOSEST(val, 25) * 2;
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}
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break;
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case LTC2945_VIN_H:
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case LTC2945_MAX_VIN_H:
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case LTC2945_MIN_VIN_H:
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case LTC2945_MAX_VIN_THRES_H:
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case LTC2945_MIN_VIN_THRES_H:
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/* 25 mV resolution. */
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val /= 25;
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break;
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case LTC2945_ADIN_H:
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case LTC2945_MAX_ADIN_H:
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case LTC2945_MIN_ADIN_THRES_H:
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case LTC2945_MAX_ADIN_THRES_H:
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case LTC2945_MIN_ADIN_H:
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/* 0.5mV resolution. */
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val *= 2;
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break;
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case LTC2945_SENSE_H:
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case LTC2945_MAX_SENSE_H:
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case LTC2945_MIN_SENSE_H:
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case LTC2945_MAX_SENSE_THRES_H:
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case LTC2945_MIN_SENSE_THRES_H:
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/*
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* 25 uV resolution. Convert to current as measured with
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* an 1 mOhm sense resistor, in mA. If a different sense
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* resistor is installed, calculate the actual current by
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* dividing the reported current by the sense resistor value
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* in mOhm.
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*/
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val = DIV_ROUND_CLOSEST(val, 25);
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break;
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default:
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return -EINVAL;
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}
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return val;
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}
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static ssize_t ltc2945_value_show(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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long long value;
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value = ltc2945_reg_to_val(dev, attr->index);
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if (value < 0)
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return value;
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return snprintf(buf, PAGE_SIZE, "%lld\n", value);
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}
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static ssize_t ltc2945_value_store(struct device *dev,
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struct device_attribute *da,
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const char *buf, size_t count)
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{
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struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
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struct regmap *regmap = dev_get_drvdata(dev);
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u8 reg = attr->index;
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unsigned long val;
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u8 regbuf[3];
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int num_regs;
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int regval;
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int ret;
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ret = kstrtoul(buf, 10, &val);
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if (ret)
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return ret;
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/* convert to register value, then clamp and write result */
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regval = ltc2945_val_to_reg(dev, reg, val);
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if (is_power_reg(reg)) {
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regval = clamp_val(regval, 0, 0xffffff);
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regbuf[0] = regval >> 16;
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regbuf[1] = (regval >> 8) & 0xff;
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regbuf[2] = regval;
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num_regs = 3;
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} else {
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regval = clamp_val(regval, 0, 0xfff) << 4;
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regbuf[0] = regval >> 8;
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regbuf[1] = regval & 0xff;
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num_regs = 2;
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}
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ret = regmap_bulk_write(regmap, reg, regbuf, num_regs);
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return ret < 0 ? ret : count;
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}
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static ssize_t ltc2945_history_store(struct device *dev,
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struct device_attribute *da,
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const char *buf, size_t count)
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{
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struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
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struct regmap *regmap = dev_get_drvdata(dev);
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u8 reg = attr->index;
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int num_regs = is_power_reg(reg) ? 3 : 2;
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u8 buf_min[3] = { 0xff, 0xff, 0xff };
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u8 buf_max[3] = { 0, 0, 0 };
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unsigned long val;
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int ret;
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ret = kstrtoul(buf, 10, &val);
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if (ret)
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return ret;
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if (val != 1)
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return -EINVAL;
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ret = regmap_update_bits(regmap, LTC2945_CONTROL, CONTROL_TEST_MODE,
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CONTROL_TEST_MODE);
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/* Reset minimum */
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ret = regmap_bulk_write(regmap, reg, buf_min, num_regs);
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if (ret)
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return ret;
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switch (reg) {
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case LTC2945_MIN_POWER_H:
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reg = LTC2945_MAX_POWER_H;
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break;
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case LTC2945_MIN_SENSE_H:
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reg = LTC2945_MAX_SENSE_H;
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break;
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case LTC2945_MIN_VIN_H:
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reg = LTC2945_MAX_VIN_H;
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break;
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case LTC2945_MIN_ADIN_H:
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reg = LTC2945_MAX_ADIN_H;
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break;
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default:
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WARN_ONCE(1, "Bad register: 0x%x\n", reg);
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return -EINVAL;
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}
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/* Reset maximum */
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ret = regmap_bulk_write(regmap, reg, buf_max, num_regs);
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/* Try resetting test mode even if there was an error */
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regmap_update_bits(regmap, LTC2945_CONTROL, CONTROL_TEST_MODE, 0);
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return ret ? : count;
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}
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static ssize_t ltc2945_bool_show(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 regmap *regmap = dev_get_drvdata(dev);
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unsigned int fault;
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int ret;
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ret = regmap_read(regmap, LTC2945_FAULT, &fault);
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if (ret < 0)
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return ret;
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fault &= attr->index;
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if (fault) /* Clear reported faults in chip register */
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regmap_update_bits(regmap, LTC2945_FAULT, attr->index, 0);
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return snprintf(buf, PAGE_SIZE, "%d\n", !!fault);
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}
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/* Input voltages */
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static SENSOR_DEVICE_ATTR_RO(in1_input, ltc2945_value, LTC2945_VIN_H);
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static SENSOR_DEVICE_ATTR_RW(in1_min, ltc2945_value, LTC2945_MIN_VIN_THRES_H);
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static SENSOR_DEVICE_ATTR_RW(in1_max, ltc2945_value, LTC2945_MAX_VIN_THRES_H);
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static SENSOR_DEVICE_ATTR_RO(in1_lowest, ltc2945_value, LTC2945_MIN_VIN_H);
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static SENSOR_DEVICE_ATTR_RO(in1_highest, ltc2945_value, LTC2945_MAX_VIN_H);
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static SENSOR_DEVICE_ATTR_WO(in1_reset_history, ltc2945_history,
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LTC2945_MIN_VIN_H);
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static SENSOR_DEVICE_ATTR_RO(in2_input, ltc2945_value, LTC2945_ADIN_H);
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static SENSOR_DEVICE_ATTR_RW(in2_min, ltc2945_value, LTC2945_MIN_ADIN_THRES_H);
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static SENSOR_DEVICE_ATTR_RW(in2_max, ltc2945_value, LTC2945_MAX_ADIN_THRES_H);
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static SENSOR_DEVICE_ATTR_RO(in2_lowest, ltc2945_value, LTC2945_MIN_ADIN_H);
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static SENSOR_DEVICE_ATTR_RO(in2_highest, ltc2945_value, LTC2945_MAX_ADIN_H);
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static SENSOR_DEVICE_ATTR_WO(in2_reset_history, ltc2945_history,
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LTC2945_MIN_ADIN_H);
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/* Voltage alarms */
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static SENSOR_DEVICE_ATTR_RO(in1_min_alarm, ltc2945_bool, FAULT_VIN_UV);
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static SENSOR_DEVICE_ATTR_RO(in1_max_alarm, ltc2945_bool, FAULT_VIN_OV);
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static SENSOR_DEVICE_ATTR_RO(in2_min_alarm, ltc2945_bool, FAULT_ADIN_UV);
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static SENSOR_DEVICE_ATTR_RO(in2_max_alarm, ltc2945_bool, FAULT_ADIN_OV);
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/* Currents (via sense resistor) */
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static SENSOR_DEVICE_ATTR_RO(curr1_input, ltc2945_value, LTC2945_SENSE_H);
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static SENSOR_DEVICE_ATTR_RW(curr1_min, ltc2945_value,
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LTC2945_MIN_SENSE_THRES_H);
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static SENSOR_DEVICE_ATTR_RW(curr1_max, ltc2945_value,
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LTC2945_MAX_SENSE_THRES_H);
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static SENSOR_DEVICE_ATTR_RO(curr1_lowest, ltc2945_value, LTC2945_MIN_SENSE_H);
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static SENSOR_DEVICE_ATTR_RO(curr1_highest, ltc2945_value,
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LTC2945_MAX_SENSE_H);
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static SENSOR_DEVICE_ATTR_WO(curr1_reset_history, ltc2945_history,
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LTC2945_MIN_SENSE_H);
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/* Current alarms */
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static SENSOR_DEVICE_ATTR_RO(curr1_min_alarm, ltc2945_bool, FAULT_SENSE_UV);
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static SENSOR_DEVICE_ATTR_RO(curr1_max_alarm, ltc2945_bool, FAULT_SENSE_OV);
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/* Power */
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static SENSOR_DEVICE_ATTR_RO(power1_input, ltc2945_value, LTC2945_POWER_H);
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static SENSOR_DEVICE_ATTR_RW(power1_min, ltc2945_value,
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LTC2945_MIN_POWER_THRES_H);
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static SENSOR_DEVICE_ATTR_RW(power1_max, ltc2945_value,
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LTC2945_MAX_POWER_THRES_H);
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static SENSOR_DEVICE_ATTR_RO(power1_input_lowest, ltc2945_value,
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LTC2945_MIN_POWER_H);
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static SENSOR_DEVICE_ATTR_RO(power1_input_highest, ltc2945_value,
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LTC2945_MAX_POWER_H);
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static SENSOR_DEVICE_ATTR_WO(power1_reset_history, ltc2945_history,
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LTC2945_MIN_POWER_H);
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/* Power alarms */
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static SENSOR_DEVICE_ATTR_RO(power1_min_alarm, ltc2945_bool, FAULT_POWER_UV);
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static SENSOR_DEVICE_ATTR_RO(power1_max_alarm, ltc2945_bool, FAULT_POWER_OV);
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static struct attribute *ltc2945_attrs[] = {
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&sensor_dev_attr_in1_input.dev_attr.attr,
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&sensor_dev_attr_in1_min.dev_attr.attr,
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&sensor_dev_attr_in1_max.dev_attr.attr,
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&sensor_dev_attr_in1_lowest.dev_attr.attr,
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&sensor_dev_attr_in1_highest.dev_attr.attr,
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&sensor_dev_attr_in1_reset_history.dev_attr.attr,
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&sensor_dev_attr_in1_min_alarm.dev_attr.attr,
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&sensor_dev_attr_in1_max_alarm.dev_attr.attr,
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&sensor_dev_attr_in2_input.dev_attr.attr,
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&sensor_dev_attr_in2_min.dev_attr.attr,
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&sensor_dev_attr_in2_max.dev_attr.attr,
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&sensor_dev_attr_in2_lowest.dev_attr.attr,
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&sensor_dev_attr_in2_highest.dev_attr.attr,
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&sensor_dev_attr_in2_reset_history.dev_attr.attr,
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&sensor_dev_attr_in2_min_alarm.dev_attr.attr,
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&sensor_dev_attr_in2_max_alarm.dev_attr.attr,
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&sensor_dev_attr_curr1_input.dev_attr.attr,
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&sensor_dev_attr_curr1_min.dev_attr.attr,
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&sensor_dev_attr_curr1_max.dev_attr.attr,
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&sensor_dev_attr_curr1_lowest.dev_attr.attr,
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&sensor_dev_attr_curr1_highest.dev_attr.attr,
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&sensor_dev_attr_curr1_reset_history.dev_attr.attr,
|
|
&sensor_dev_attr_curr1_min_alarm.dev_attr.attr,
|
|
&sensor_dev_attr_curr1_max_alarm.dev_attr.attr,
|
|
|
|
&sensor_dev_attr_power1_input.dev_attr.attr,
|
|
&sensor_dev_attr_power1_min.dev_attr.attr,
|
|
&sensor_dev_attr_power1_max.dev_attr.attr,
|
|
&sensor_dev_attr_power1_input_lowest.dev_attr.attr,
|
|
&sensor_dev_attr_power1_input_highest.dev_attr.attr,
|
|
&sensor_dev_attr_power1_reset_history.dev_attr.attr,
|
|
&sensor_dev_attr_power1_min_alarm.dev_attr.attr,
|
|
&sensor_dev_attr_power1_max_alarm.dev_attr.attr,
|
|
|
|
NULL,
|
|
};
|
|
ATTRIBUTE_GROUPS(ltc2945);
|
|
|
|
static const struct regmap_config ltc2945_regmap_config = {
|
|
.reg_bits = 8,
|
|
.val_bits = 8,
|
|
.max_register = LTC2945_MIN_ADIN_THRES_L,
|
|
};
|
|
|
|
static int ltc2945_probe(struct i2c_client *client,
|
|
const struct i2c_device_id *id)
|
|
{
|
|
struct device *dev = &client->dev;
|
|
struct device *hwmon_dev;
|
|
struct regmap *regmap;
|
|
|
|
regmap = devm_regmap_init_i2c(client, <c2945_regmap_config);
|
|
if (IS_ERR(regmap)) {
|
|
dev_err(dev, "failed to allocate register map\n");
|
|
return PTR_ERR(regmap);
|
|
}
|
|
|
|
/* Clear faults */
|
|
regmap_write(regmap, LTC2945_FAULT, 0x00);
|
|
|
|
hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
|
|
regmap,
|
|
ltc2945_groups);
|
|
return PTR_ERR_OR_ZERO(hwmon_dev);
|
|
}
|
|
|
|
static const struct i2c_device_id ltc2945_id[] = {
|
|
{"ltc2945", 0},
|
|
{ }
|
|
};
|
|
|
|
MODULE_DEVICE_TABLE(i2c, ltc2945_id);
|
|
|
|
static struct i2c_driver ltc2945_driver = {
|
|
.driver = {
|
|
.name = "ltc2945",
|
|
},
|
|
.probe = ltc2945_probe,
|
|
.id_table = ltc2945_id,
|
|
};
|
|
|
|
module_i2c_driver(ltc2945_driver);
|
|
|
|
MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
|
|
MODULE_DESCRIPTION("LTC2945 driver");
|
|
MODULE_LICENSE("GPL");
|