linux-imx

/*

 * max31790.c - Part of lm_sensors, Linux kernel modules for hardware

 *             monitoring.

 *

 * (C) 2015 by Il Han <corone.il.han@gmail.com>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 */

​

#include <linux/err.h>

#include <linux/hwmon.h>

#include <linux/i2c.h>

#include <linux/init.h>

#include <linux/jiffies.h>

#include <linux/module.h>

#include <linux/slab.h>

​

/* MAX31790 registers */

#define MAX31790_REG_GLOBAL_CONFIG  0x00

#define MAX31790_REG_FAN_CONFIG(ch) (0x02 + (ch))

#define MAX31790_REG_FAN_DYNAMICS(ch)   (0x08 + (ch))

#define MAX31790_REG_FAN_FAULT_STATUS2  0x10

#define MAX31790_REG_FAN_FAULT_STATUS1  0x11

#define MAX31790_REG_TACH_COUNT(ch) (0x18 + (ch) * 2)

#define MAX31790_REG_PWM_DUTY_CYCLE(ch) (0x30 + (ch) * 2)

#define MAX31790_REG_PWMOUT(ch)     (0x40 + (ch) * 2)

#define MAX31790_REG_TARGET_COUNT(ch)   (0x50 + (ch) * 2)

​

/* Fan Config register bits */

#define MAX31790_FAN_CFG_RPM_MODE   0x80

#define MAX31790_FAN_CFG_TACH_INPUT_EN  0x08

#define MAX31790_FAN_CFG_TACH_INPUT 0x01

​

/* Fan Dynamics register bits */

#define MAX31790_FAN_DYN_SR_SHIFT   5

#define MAX31790_FAN_DYN_SR_MASK    0xE0

#define SR_FROM_REG(reg)        (((reg) & MAX31790_FAN_DYN_SR_MASK) \

                     >> MAX31790_FAN_DYN_SR_SHIFT)

​

#define FAN_RPM_MIN         120

#define FAN_RPM_MAX         7864320

​

#define RPM_FROM_REG(reg, sr)       (((reg) >> 4) ? \

                     ((60 * (sr) * 8192) / ((reg) >> 4)) : \

                     FAN_RPM_MAX)

#define RPM_TO_REG(rpm, sr)     ((60 * (sr) * 8192) / ((rpm) * 2))

​

#define NR_CHANNEL          6

​

/*

 * Client data (each client gets its own)

 */

struct max31790_data {

    struct i2c_client *client;

    struct mutex update_lock;