515 lines
11 KiB
C
515 lines
11 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Hardware monitoring driver for Maxim MAX6620
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*
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* Originally from L. Grunenberg.
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* (C) 2012 by L. Grunenberg <contact@lgrunenberg.de>
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*
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* Copyright (c) 2021 Dell Inc. or its subsidiaries. All Rights Reserved.
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*
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* based on code written by :
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* 2007 by Hans J. Koch <hjk@hansjkoch.de>
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* John Morris <john.morris@spirentcom.com>
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* Copyright (c) 2003 Spirent Communications
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* and Claus Gindhart <claus.gindhart@kontron.com>
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*
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* This module has only been tested with the MAX6620 chip.
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*
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* The datasheet was last seen at:
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*
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* http://pdfserv.maxim-ic.com/en/ds/MAX6620.pdf
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*
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*/
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#include <linux/bits.h>
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#include <linux/err.h>
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#include <linux/hwmon.h>
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#include <linux/i2c.h>
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#include <linux/init.h>
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#include <linux/jiffies.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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/*
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* MAX 6620 registers
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*/
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#define MAX6620_REG_CONFIG 0x00
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#define MAX6620_REG_FAULT 0x01
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#define MAX6620_REG_CONF_FAN0 0x02
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#define MAX6620_REG_CONF_FAN1 0x03
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#define MAX6620_REG_CONF_FAN2 0x04
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#define MAX6620_REG_CONF_FAN3 0x05
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#define MAX6620_REG_DYN_FAN0 0x06
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#define MAX6620_REG_DYN_FAN1 0x07
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#define MAX6620_REG_DYN_FAN2 0x08
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#define MAX6620_REG_DYN_FAN3 0x09
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#define MAX6620_REG_TACH0 0x10
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#define MAX6620_REG_TACH1 0x12
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#define MAX6620_REG_TACH2 0x14
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#define MAX6620_REG_TACH3 0x16
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#define MAX6620_REG_VOLT0 0x18
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#define MAX6620_REG_VOLT1 0x1A
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#define MAX6620_REG_VOLT2 0x1C
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#define MAX6620_REG_VOLT3 0x1E
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#define MAX6620_REG_TAR0 0x20
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#define MAX6620_REG_TAR1 0x22
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#define MAX6620_REG_TAR2 0x24
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#define MAX6620_REG_TAR3 0x26
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#define MAX6620_REG_DAC0 0x28
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#define MAX6620_REG_DAC1 0x2A
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#define MAX6620_REG_DAC2 0x2C
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#define MAX6620_REG_DAC3 0x2E
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/*
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* Config register bits
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*/
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#define MAX6620_CFG_RUN BIT(7)
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#define MAX6620_CFG_POR BIT(6)
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#define MAX6620_CFG_TIMEOUT BIT(5)
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#define MAX6620_CFG_FULLFAN BIT(4)
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#define MAX6620_CFG_OSC BIT(3)
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#define MAX6620_CFG_WD_MASK (BIT(2) | BIT(1))
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#define MAX6620_CFG_WD_2 BIT(1)
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#define MAX6620_CFG_WD_6 BIT(2)
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#define MAX6620_CFG_WD10 (BIT(2) | BIT(1))
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#define MAX6620_CFG_WD BIT(0)
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/*
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* Failure status register bits
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*/
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#define MAX6620_FAIL_TACH0 BIT(4)
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#define MAX6620_FAIL_TACH1 BIT(5)
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#define MAX6620_FAIL_TACH2 BIT(6)
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#define MAX6620_FAIL_TACH3 BIT(7)
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#define MAX6620_FAIL_MASK0 BIT(0)
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#define MAX6620_FAIL_MASK1 BIT(1)
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#define MAX6620_FAIL_MASK2 BIT(2)
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#define MAX6620_FAIL_MASK3 BIT(3)
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#define MAX6620_CLOCK_FREQ 8192 /* Clock frequency in Hz */
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#define MAX6620_PULSE_PER_REV 2 /* Tachometer pulses per revolution */
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/* Minimum and maximum values of the FAN-RPM */
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#define FAN_RPM_MIN 240
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#define FAN_RPM_MAX 30000
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static const u8 config_reg[] = {
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MAX6620_REG_CONF_FAN0,
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MAX6620_REG_CONF_FAN1,
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MAX6620_REG_CONF_FAN2,
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MAX6620_REG_CONF_FAN3,
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};
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static const u8 dyn_reg[] = {
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MAX6620_REG_DYN_FAN0,
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MAX6620_REG_DYN_FAN1,
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MAX6620_REG_DYN_FAN2,
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MAX6620_REG_DYN_FAN3,
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};
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static const u8 tach_reg[] = {
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MAX6620_REG_TACH0,
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MAX6620_REG_TACH1,
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MAX6620_REG_TACH2,
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MAX6620_REG_TACH3,
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};
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static const u8 target_reg[] = {
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MAX6620_REG_TAR0,
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MAX6620_REG_TAR1,
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MAX6620_REG_TAR2,
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MAX6620_REG_TAR3,
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};
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/*
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* Client data (each client gets its own)
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*/
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struct max6620_data {
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struct i2c_client *client;
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struct mutex update_lock;
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bool valid; /* false until following fields are valid */
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unsigned long last_updated; /* in jiffies */
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/* register values */
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u8 fancfg[4];
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u8 fandyn[4];
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u8 fault;
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u16 tach[4];
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u16 target[4];
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};
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static u8 max6620_fan_div_from_reg(u8 val)
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{
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return BIT((val & 0xE0) >> 5);
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}
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static u16 max6620_fan_rpm_to_tach(u8 div, int rpm)
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{
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return (60 * div * MAX6620_CLOCK_FREQ) / (rpm * MAX6620_PULSE_PER_REV);
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}
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static int max6620_fan_tach_to_rpm(u8 div, u16 tach)
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{
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return (60 * div * MAX6620_CLOCK_FREQ) / (tach * MAX6620_PULSE_PER_REV);
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}
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static int max6620_update_device(struct device *dev)
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{
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struct max6620_data *data = dev_get_drvdata(dev);
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struct i2c_client *client = data->client;
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int i;
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int ret = 0;
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mutex_lock(&data->update_lock);
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if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
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for (i = 0; i < 4; i++) {
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ret = i2c_smbus_read_byte_data(client, config_reg[i]);
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if (ret < 0)
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goto error;
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data->fancfg[i] = ret;
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ret = i2c_smbus_read_byte_data(client, dyn_reg[i]);
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if (ret < 0)
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goto error;
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data->fandyn[i] = ret;
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ret = i2c_smbus_read_byte_data(client, tach_reg[i]);
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if (ret < 0)
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goto error;
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data->tach[i] = (ret << 3) & 0x7f8;
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ret = i2c_smbus_read_byte_data(client, tach_reg[i] + 1);
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if (ret < 0)
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goto error;
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data->tach[i] |= (ret >> 5) & 0x7;
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ret = i2c_smbus_read_byte_data(client, target_reg[i]);
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if (ret < 0)
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goto error;
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data->target[i] = (ret << 3) & 0x7f8;
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ret = i2c_smbus_read_byte_data(client, target_reg[i] + 1);
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if (ret < 0)
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goto error;
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data->target[i] |= (ret >> 5) & 0x7;
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}
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/*
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* Alarms are cleared on read in case the condition that
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* caused the alarm is removed. Keep the value latched here
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* for providing the register through different alarm files.
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*/
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ret = i2c_smbus_read_byte_data(client, MAX6620_REG_FAULT);
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if (ret < 0)
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goto error;
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data->fault |= (ret >> 4) & (ret & 0x0F);
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data->last_updated = jiffies;
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data->valid = true;
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}
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error:
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mutex_unlock(&data->update_lock);
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return ret;
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}
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static umode_t
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max6620_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr,
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int channel)
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{
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switch (type) {
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case hwmon_fan:
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switch (attr) {
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case hwmon_fan_alarm:
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case hwmon_fan_input:
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return 0444;
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case hwmon_fan_div:
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case hwmon_fan_target:
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return 0644;
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default:
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break;
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}
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break;
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default:
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break;
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}
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return 0;
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}
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static int
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max6620_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
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int channel, long *val)
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{
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struct max6620_data *data;
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struct i2c_client *client;
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int ret;
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u8 div;
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u8 val1;
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u8 val2;
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ret = max6620_update_device(dev);
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if (ret < 0)
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return ret;
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data = dev_get_drvdata(dev);
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client = data->client;
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switch (type) {
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case hwmon_fan:
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switch (attr) {
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case hwmon_fan_alarm:
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mutex_lock(&data->update_lock);
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*val = !!(data->fault & BIT(channel));
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/* Setting TACH count to re-enable fan fault detection */
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if (*val == 1) {
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val1 = (data->target[channel] >> 3) & 0xff;
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val2 = (data->target[channel] << 5) & 0xe0;
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ret = i2c_smbus_write_byte_data(client,
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target_reg[channel], val1);
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if (ret < 0) {
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mutex_unlock(&data->update_lock);
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return ret;
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}
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ret = i2c_smbus_write_byte_data(client,
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target_reg[channel] + 1, val2);
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if (ret < 0) {
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mutex_unlock(&data->update_lock);
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return ret;
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}
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data->fault &= ~BIT(channel);
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}
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mutex_unlock(&data->update_lock);
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break;
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case hwmon_fan_div:
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*val = max6620_fan_div_from_reg(data->fandyn[channel]);
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break;
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case hwmon_fan_input:
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if (data->tach[channel] == 0) {
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*val = 0;
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} else {
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div = max6620_fan_div_from_reg(data->fandyn[channel]);
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*val = max6620_fan_tach_to_rpm(div, data->tach[channel]);
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}
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break;
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case hwmon_fan_target:
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if (data->target[channel] == 0) {
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*val = 0;
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} else {
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div = max6620_fan_div_from_reg(data->fandyn[channel]);
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*val = max6620_fan_tach_to_rpm(div, data->target[channel]);
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}
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break;
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default:
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return -EOPNOTSUPP;
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}
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break;
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default:
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return -EOPNOTSUPP;
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}
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return 0;
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}
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static int
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max6620_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
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int channel, long val)
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{
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struct max6620_data *data;
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struct i2c_client *client;
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int ret;
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u8 div;
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u16 tach;
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u8 val1;
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u8 val2;
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ret = max6620_update_device(dev);
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if (ret < 0)
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return ret;
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data = dev_get_drvdata(dev);
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client = data->client;
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mutex_lock(&data->update_lock);
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switch (type) {
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case hwmon_fan:
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switch (attr) {
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case hwmon_fan_div:
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switch (val) {
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case 1:
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div = 0;
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break;
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case 2:
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div = 1;
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break;
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case 4:
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div = 2;
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break;
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case 8:
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div = 3;
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break;
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case 16:
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div = 4;
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break;
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case 32:
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div = 5;
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break;
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default:
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ret = -EINVAL;
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goto error;
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}
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data->fandyn[channel] &= 0x1F;
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data->fandyn[channel] |= div << 5;
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ret = i2c_smbus_write_byte_data(client, dyn_reg[channel],
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data->fandyn[channel]);
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break;
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case hwmon_fan_target:
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val = clamp_val(val, FAN_RPM_MIN, FAN_RPM_MAX);
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div = max6620_fan_div_from_reg(data->fandyn[channel]);
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tach = max6620_fan_rpm_to_tach(div, val);
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val1 = (tach >> 3) & 0xff;
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val2 = (tach << 5) & 0xe0;
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ret = i2c_smbus_write_byte_data(client, target_reg[channel], val1);
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if (ret < 0)
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break;
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ret = i2c_smbus_write_byte_data(client, target_reg[channel] + 1, val2);
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if (ret < 0)
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break;
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/* Setting TACH count re-enables fan fault detection */
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data->fault &= ~BIT(channel);
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break;
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default:
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ret = -EOPNOTSUPP;
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break;
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}
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break;
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default:
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ret = -EOPNOTSUPP;
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break;
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}
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error:
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mutex_unlock(&data->update_lock);
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return ret;
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}
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static const struct hwmon_channel_info *max6620_info[] = {
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HWMON_CHANNEL_INFO(fan,
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HWMON_F_INPUT | HWMON_F_DIV | HWMON_F_TARGET | HWMON_F_ALARM,
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HWMON_F_INPUT | HWMON_F_DIV | HWMON_F_TARGET | HWMON_F_ALARM,
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HWMON_F_INPUT | HWMON_F_DIV | HWMON_F_TARGET | HWMON_F_ALARM,
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HWMON_F_INPUT | HWMON_F_DIV | HWMON_F_TARGET | HWMON_F_ALARM),
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NULL
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};
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static const struct hwmon_ops max6620_hwmon_ops = {
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.read = max6620_read,
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.write = max6620_write,
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.is_visible = max6620_is_visible,
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};
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static const struct hwmon_chip_info max6620_chip_info = {
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.ops = &max6620_hwmon_ops,
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.info = max6620_info,
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};
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static int max6620_init_client(struct max6620_data *data)
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{
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struct i2c_client *client = data->client;
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int config;
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int err;
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int i;
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int reg;
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config = i2c_smbus_read_byte_data(client, MAX6620_REG_CONFIG);
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if (config < 0) {
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dev_err(&client->dev, "Error reading config, aborting.\n");
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return config;
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}
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/*
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* Set bit 4, disable other fans from going full speed on a fail
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* failure.
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*/
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err = i2c_smbus_write_byte_data(client, MAX6620_REG_CONFIG, config | 0x10);
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if (err < 0) {
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dev_err(&client->dev, "Config write error, aborting.\n");
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return err;
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}
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for (i = 0; i < 4; i++) {
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reg = i2c_smbus_read_byte_data(client, config_reg[i]);
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if (reg < 0)
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return reg;
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data->fancfg[i] = reg;
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/* Enable RPM mode */
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data->fancfg[i] |= 0xa8;
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err = i2c_smbus_write_byte_data(client, config_reg[i], data->fancfg[i]);
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if (err < 0)
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return err;
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/* 2 counts (001) and Rate change 100 (0.125 secs) */
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data->fandyn[i] = 0x30;
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err = i2c_smbus_write_byte_data(client, dyn_reg[i], data->fandyn[i]);
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if (err < 0)
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return err;
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}
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return 0;
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}
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static int max6620_probe(struct i2c_client *client)
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{
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struct device *dev = &client->dev;
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struct max6620_data *data;
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struct device *hwmon_dev;
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int err;
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data = devm_kzalloc(dev, sizeof(struct max6620_data), GFP_KERNEL);
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if (!data)
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return -ENOMEM;
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data->client = client;
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mutex_init(&data->update_lock);
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err = max6620_init_client(data);
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if (err)
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return err;
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hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
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data,
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&max6620_chip_info,
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NULL);
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return PTR_ERR_OR_ZERO(hwmon_dev);
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}
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static const struct i2c_device_id max6620_id[] = {
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{ "max6620", 0 },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, max6620_id);
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static struct i2c_driver max6620_driver = {
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.class = I2C_CLASS_HWMON,
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.driver = {
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.name = "max6620",
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},
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.probe_new = max6620_probe,
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.id_table = max6620_id,
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};
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module_i2c_driver(max6620_driver);
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MODULE_AUTHOR("Lucas Grunenberg");
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MODULE_DESCRIPTION("MAX6620 sensor driver");
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MODULE_LICENSE("GPL");
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