// SPDX-License-Identifier: GPL-2.0-or-later /* * max6650.c - Part of lm_sensors, Linux kernel modules for hardware * monitoring. * * (C) 2007 by Hans J. Koch <[email protected]> * * based on code written by John Morris <[email protected]> * Copyright (c) 2003 Spirent Communications * and Claus Gindhart <[email protected]> * * This module has only been tested with the MAX6650 chip. It should * also work with the MAX6651. It does not distinguish max6650 and max6651 * chips. * * The datasheet was last seen at: * * http://pdfserv.maxim-ic.com/en/ds/MAX6650-MAX6651.pdf */ #include <linux/module.h> #include <linux/init.h> #include <linux/slab.h> #include <linux/jiffies.h> #include <linux/i2c.h> #include <linux/hwmon.h> #include <linux/hwmon-sysfs.h> #include <linux/err.h> #include <linux/of.h> #include <linux/thermal.h> /* * Insmod parameters */ /* fan_voltage: 5=5V fan, 12=12V fan, 0=don't change */ static int fan_voltage; /* prescaler: Possible values are 1, 2, 4, 8, 16 or 0 for don't change */ static int prescaler; /* clock: The clock frequency of the chip (max6651 can be clocked externally) */ static int clock = …; module_param(fan_voltage, int, 0444); module_param(prescaler, int, 0444); module_param(clock, int, 0444); /* * MAX 6650/6651 registers */ #define MAX6650_REG_SPEED … #define MAX6650_REG_CONFIG … #define MAX6650_REG_GPIO_DEF … #define MAX6650_REG_DAC … #define MAX6650_REG_ALARM_EN … #define MAX6650_REG_ALARM … #define MAX6650_REG_TACH0 … #define MAX6650_REG_TACH1 … #define MAX6650_REG_TACH2 … #define MAX6650_REG_TACH3 … #define MAX6650_REG_GPIO_STAT … #define MAX6650_REG_COUNT … /* * Config register bits */ #define MAX6650_CFG_V12 … #define MAX6650_CFG_PRESCALER_MASK … #define MAX6650_CFG_PRESCALER_2 … #define MAX6650_CFG_PRESCALER_4 … #define MAX6650_CFG_PRESCALER_8 … #define MAX6650_CFG_PRESCALER_16 … #define MAX6650_CFG_MODE_MASK … #define MAX6650_CFG_MODE_ON … #define MAX6650_CFG_MODE_OFF … #define MAX6650_CFG_MODE_CLOSED_LOOP … #define MAX6650_CFG_MODE_OPEN_LOOP … #define MAX6650_COUNT_MASK … /* * Alarm status register bits */ #define MAX6650_ALRM_MAX … #define MAX6650_ALRM_MIN … #define MAX6650_ALRM_TACH … #define MAX6650_ALRM_GPIO1 … #define MAX6650_ALRM_GPIO2 … /* Minimum and maximum values of the FAN-RPM */ #define FAN_RPM_MIN … #define FAN_RPM_MAX … #define DIV_FROM_REG(reg) … #define DAC_LIMIT(v12) … /* * Client data (each client gets its own) */ struct max6650_data { … }; static const u8 tach_reg[] = …; static const struct of_device_id __maybe_unused max6650_dt_match[] = …; MODULE_DEVICE_TABLE(of, max6650_dt_match); static int dac_to_pwm(int dac, bool v12) { … } static u8 pwm_to_dac(unsigned int pwm, bool v12) { … } static struct max6650_data *max6650_update_device(struct device *dev) { … } /* * Change the operating mode of the chip (if needed). * mode is one of the MAX6650_CFG_MODE_* values. */ static int max6650_set_operating_mode(struct max6650_data *data, u8 mode) { … } /* * Set the fan speed to the specified RPM (or read back the RPM setting). * This works in closed loop mode only. Use pwm1 for open loop speed setting. * * The MAX6650/1 will automatically control fan speed when in closed loop * mode. * * Assumptions: * * 1) The MAX6650/1 internal 254kHz clock frequency is set correctly. Use * the clock module parameter if you need to fine tune this. * * 2) The prescaler (low three bits of the config register) has already * been set to an appropriate value. Use the prescaler module parameter * if your BIOS doesn't initialize the chip properly. * * The relevant equations are given on pages 21 and 22 of the datasheet. * * From the datasheet, the relevant equation when in regulation is: * * [fCLK / (128 x (KTACH + 1))] = 2 x FanSpeed / KSCALE * * where: * * fCLK is the oscillator frequency (either the 254kHz internal * oscillator or the externally applied clock) * * KTACH is the value in the speed register * * FanSpeed is the speed of the fan in rps * * KSCALE is the prescaler value (1, 2, 4, 8, or 16) * * When reading, we need to solve for FanSpeed. When writing, we need to * solve for KTACH. * * Note: this tachometer is completely separate from the tachometers * used to measure the fan speeds. Only one fan's speed (fan1) is * controlled. */ static int max6650_set_target(struct max6650_data *data, unsigned long rpm) { … } /* * Get gpio alarm status: * Possible values: * 0 = no alarm * 1 = alarm */ static ssize_t alarm_show(struct device *dev, struct device_attribute *devattr, char *buf) { … } static SENSOR_DEVICE_ATTR_RO(gpio1_alarm, alarm, MAX6650_ALRM_GPIO1); static SENSOR_DEVICE_ATTR_RO(gpio2_alarm, alarm, MAX6650_ALRM_GPIO2); static umode_t max6650_attrs_visible(struct kobject *kobj, struct attribute *a, int n) { … } static struct attribute *max6650_attrs[] = …; static const struct attribute_group max6650_group = …; static const struct attribute_group *max6650_groups[] = …; static int max6650_init_client(struct max6650_data *data, struct i2c_client *client) { … } static int max6650_get_max_state(struct thermal_cooling_device *cdev, unsigned long *state) { … } static int max6650_get_cur_state(struct thermal_cooling_device *cdev, unsigned long *state) { … } static int max6650_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state) { … } static const struct thermal_cooling_device_ops max6650_cooling_ops = …; static int max6650_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, long *val) { … } static const u8 max6650_pwm_modes[] = …; static int max6650_write(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, long val) { … } static umode_t max6650_is_visible(const void *_data, enum hwmon_sensor_types type, u32 attr, int channel) { … } static const struct hwmon_channel_info * const max6650_info[] = …; static const struct hwmon_ops max6650_hwmon_ops = …; static const struct hwmon_chip_info max6650_chip_info = …; static const struct i2c_device_id max6650_id[]; static int max6650_probe(struct i2c_client *client) { … } static const struct i2c_device_id max6650_id[] = …; MODULE_DEVICE_TABLE(i2c, max6650_id); static struct i2c_driver max6650_driver = …; module_i2c_driver(…) …; MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …;
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