path: root/drivers/hwmon/amc6821.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * amc6821.c - Part of lm_sensors, Linux kernel modules for hardware
 *	       monitoring
 * Copyright (C) 2009 T. Mertelj <tomaz.mertelj@guest.arnes.si>
 *
 * Based on max6650.c:
 * Copyright (C) 2007 Hans J. Koch <hjk@hansjkoch.de>
 *
 * Conversion to regmap and with_info API:
 * Copyright (C) 2024 Guenter Roeck <linux@roeck-us.net>
 */

#include <linux/bitfield.h>
#include <linux/bitops.h>
#include <linux/bits.h>
#include <linux/err.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/minmax.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of_platform.h>
#include <linux/pwm.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include <linux/thermal.h>

#include <dt-bindings/pwm/pwm.h>

/*
 * Addresses to scan.
 */

static const unsigned short normal_i2c[] = {0x18, 0x19, 0x1a, 0x2c, 0x2d, 0x2e,
	0x4c, 0x4d, 0x4e, I2C_CLIENT_END};

/*
 * Insmod parameters
 */

static int pwminv = -1; /*Inverted PWM output. */
module_param(pwminv, int, 0444);

static int init = 1; /*Power-on initialization.*/
module_param(init, int, 0444);

#define AMC6821_REG_DEV_ID		0x3D
#define AMC6821_REG_COMP_ID		0x3E
#define AMC6821_REG_CONF1		0x00
#define AMC6821_REG_CONF2		0x01
#define AMC6821_REG_CONF3		0x3F
#define AMC6821_REG_CONF4		0x04
#define AMC6821_REG_STAT1		0x02
#define AMC6821_REG_STAT2		0x03
#define AMC6821_REG_TEMP_LO		0x06
#define AMC6821_REG_TDATA_LOW		0x08
#define AMC6821_REG_TDATA_HI		0x09
#define AMC6821_REG_LTEMP_HI		0x0A
#define AMC6821_REG_RTEMP_HI		0x0B
#define AMC6821_REG_LTEMP_LIMIT_MIN	0x15
#define AMC6821_REG_LTEMP_LIMIT_MAX	0x14
#define AMC6821_REG_RTEMP_LIMIT_MIN	0x19
#define AMC6821_REG_RTEMP_LIMIT_MAX	0x18
#define AMC6821_REG_LTEMP_CRIT		0x1B
#define AMC6821_REG_RTEMP_CRIT		0x1D
#define AMC6821_REG_PSV_TEMP		0x1C
#define AMC6821_REG_DCY			0x22
#define AMC6821_REG_LTEMP_FAN_CTRL	0x24
#define AMC6821_REG_RTEMP_FAN_CTRL	0x25
#define AMC6821_REG_DCY_LOW_TEMP	0x21

#define AMC6821_REG_TACH_LLIMITL	0x10
#define AMC6821_REG_TACH_HLIMITL	0x12
#define AMC6821_REG_TACH_SETTINGL	0x1e

#define AMC6821_CONF1_START		BIT(0)
#define AMC6821_CONF1_FAN_INT_EN	BIT(1)
#define AMC6821_CONF1_FANIE		BIT(2)
#define AMC6821_CONF1_PWMINV		BIT(3)
#define AMC6821_CONF1_FAN_FAULT_EN	BIT(4)
#define AMC6821_CONF1_FDRC0		BIT(5)
#define AMC6821_CONF1_FDRC1		BIT(6)
#define AMC6821_CONF1_THERMOVIE		BIT(7)

#define AMC6821_CONF2_PWM_EN		BIT(0)
#define AMC6821_CONF2_TACH_MODE		BIT(1)
#define AMC6821_CONF2_TACH_EN		BIT(2)
#define AMC6821_CONF2_RTFIE		BIT(3)
#define AMC6821_CONF2_LTOIE		BIT(4)
#define AMC6821_CONF2_RTOIE		BIT(5)
#define AMC6821_CONF2_PSVIE		BIT(6)
#define AMC6821_CONF2_RST		BIT(7)

#define AMC6821_CONF3_THERM_FAN_EN	BIT(7)
#define AMC6821_CONF3_REV_MASK		GENMASK(3, 0)

#define AMC6821_CONF4_OVREN		BIT(4)
#define AMC6821_CONF4_TACH_FAST		BIT(5)
#define AMC6821_CONF4_PSPR		BIT(6)
#define AMC6821_CONF4_MODE		BIT(7)

#define AMC6821_STAT1_RPM_ALARM		BIT(0)
#define AMC6821_STAT1_FANS		BIT(1)
#define AMC6821_STAT1_RTH		BIT(2)
#define AMC6821_STAT1_RTL		BIT(3)
#define AMC6821_STAT1_R_THERM		BIT(4)
#define AMC6821_STAT1_RTF		BIT(5)
#define AMC6821_STAT1_LTH		BIT(6)
#define AMC6821_STAT1_LTL		BIT(7)

#define AMC6821_STAT2_RTC		BIT(3)
#define AMC6821_STAT2_LTC		BIT(4)
#define AMC6821_STAT2_LPSV		BIT(5)
#define AMC6821_STAT2_L_THERM		BIT(6)
#define AMC6821_STAT2_THERM_IN		BIT(7)

#define AMC6821_TEMP_SLOPE_MASK		GENMASK(2, 0)
#define AMC6821_TEMP_LIMIT_MASK		GENMASK(7, 3)

/*
 * Client data (each client gets its own)
 */

struct amc6821_data {
	struct regmap *regmap;
	struct mutex update_lock;
	unsigned long fan_state;
	unsigned long fan_max_state;
	unsigned int *fan_cooling_levels;
	enum pwm_polarity pwm_polarity;
};

/*
 * Return 0 on success or negative error code.
 *
 * temps returns set of three temperatures, in °C:
 * temps[0]: Passive cooling temperature, applies to both channels
 * temps[1]: Low temperature, start slope calculations
 * temps[2]: High temperature
 *
 * Channel 0: local, channel 1: remote.
 */
static int amc6821_get_auto_point_temps(struct regmap *regmap, int channel, u8 *temps)
{
	u32 regs[] = {
		AMC6821_REG_DCY_LOW_TEMP,
		AMC6821_REG_PSV_TEMP,
		channel ? AMC6821_REG_RTEMP_FAN_CTRL : AMC6821_REG_LTEMP_FAN_CTRL
	};
	u8 regvals[3];
	int slope;
	int err;

	err = regmap_multi_reg_read(regmap, regs, regvals, 3);
	if (err)
		return err;
	temps[0] = regvals[1];
	temps[1] = FIELD_GET(AMC6821_TEMP_LIMIT_MASK, regvals[2]) * 4;

	/* slope is 32 >> <slope bits> in °C */
	slope = 32 >> FIELD_GET(AMC6821_TEMP_SLOPE_MASK, regvals[2]);
	if (slope)
		temps[2] = temps[1] + DIV_ROUND_CLOSEST(255 - regvals[0], slope);
	else
		temps[2] = 255;

	return 0;
}

static int amc6821_temp_read_values(struct regmap *regmap, u32 attr, int channel, long *val)
{
	int reg, err;
	u32 regval;

	switch (attr) {
	case hwmon_temp_input:
		reg = channel ? AMC6821_