path: root/drivers/hwmon/ina3221.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * INA3221 Triple Current/Voltage Monitor
 *
 * Copyright (C) 2016 Texas Instruments Incorporated - https://www.ti.com/
 *	Andrew F. Davis <afd@ti.com>
 */

#include <linux/debugfs.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/pm_runtime.h>
#include <linux/regmap.h>
#include <linux/util_macros.h>

#define INA3221_DRIVER_NAME		"ina3221"

#define INA3221_CONFIG			0x00
#define INA3221_SHUNT1			0x01
#define INA3221_BUS1			0x02
#define INA3221_SHUNT2			0x03
#define INA3221_BUS2			0x04
#define INA3221_SHUNT3			0x05
#define INA3221_BUS3			0x06
#define INA3221_CRIT1			0x07
#define INA3221_WARN1			0x08
#define INA3221_CRIT2			0x09
#define INA3221_WARN2			0x0a
#define INA3221_CRIT3			0x0b
#define INA3221_WARN3			0x0c
#define INA3221_SHUNT_SUM		0x0d
#define INA3221_CRIT_SUM		0x0e
#define INA3221_MASK_ENABLE		0x0f

#define INA3221_CONFIG_MODE_MASK	GENMASK(2, 0)
#define INA3221_CONFIG_MODE_POWERDOWN	0
#define INA3221_CONFIG_MODE_SHUNT	BIT(0)
#define INA3221_CONFIG_MODE_BUS		BIT(1)
#define INA3221_CONFIG_MODE_CONTINUOUS	BIT(2)
#define INA3221_CONFIG_VSH_CT_SHIFT	3
#define INA3221_CONFIG_VSH_CT_MASK	GENMASK(5, 3)
#define INA3221_CONFIG_VSH_CT(x)	(((x) & GENMASK(5, 3)) >> 3)
#define INA3221_CONFIG_VBUS_CT_SHIFT	6
#define INA3221_CONFIG_VBUS_CT_MASK	GENMASK(8, 6)
#define INA3221_CONFIG_VBUS_CT(x)	(((x) & GENMASK(8, 6)) >> 6)
#define INA3221_CONFIG_AVG_SHIFT	9
#define INA3221_CONFIG_AVG_MASK		GENMASK(11, 9)
#define INA3221_CONFIG_AVG(x)		(((x) & GENMASK(11, 9)) >> 9)
#define INA3221_CONFIG_CHs_EN_MASK	GENMASK(14, 12)
#define INA3221_CONFIG_CHx_EN(x)	BIT(14 - (x))

#define INA3221_MASK_ENABLE_SCC_MASK	GENMASK(14, 12)

#define INA3221_CONFIG_DEFAULT		0x7127
#define INA3221_RSHUNT_DEFAULT		10000

enum ina3221_fields {
	/* Configuration */
	F_RST,

	/* Status Flags */
	F_CVRF,

	/* Warning Flags */
	F_WF3, F_WF2, F_WF1,

	/* Alert Flags: SF is the summation-alert flag */
	F_SF, F_CF3, F_CF2, F_CF1,

	/* sentinel */
	F_MAX_FIELDS
};

static const struct reg_field ina3221_reg_fields[] = {
	[F_RST] = REG_FIELD(INA3221_CONFIG, 15, 15),

	[F_CVRF] = REG_FIELD(INA3221_MASK_ENABLE, 0, 0),
	[F_WF3] = REG_FIELD(INA3221_MASK_ENABLE, 3, 3),
	[F_WF2] = REG_FIELD(INA3221_MASK_ENABLE, 4, 4),
	[F_WF1] = REG_FIELD(INA3221_MASK_ENABLE, 5, 5),
	[F_SF] = REG_FIELD(INA3221_MASK_ENABLE, 6, 6),
	[F_CF3] = REG_FIELD(INA3221_MASK_ENABLE, 7, 7),
	[F_CF2] = REG_FIELD(INA3221_MASK_ENABLE, 8, 8),
	[F_CF1] = REG_FIELD(INA3221_MASK_ENABLE, 9, 9),
};

enum ina3221_channels {
	INA3221_CHANNEL1,
	INA3221_CHANNEL2,
	INA3221_CHANNEL3,
	INA3221_NUM_CHANNELS
};

/**
 * struct ina3221_input - channel input source specific information
 * @label: label of channel input source
 * @shunt_resistor: shunt resistor value of channel input source
 * @disconnected: connection status of channel input source
 * @summation_disable: channel summation status of input source
 */
struct ina3221_input {
	const char *label;
	int shunt_resistor;
	bool disconnected;
	bool summation_disable;
};

/**
 * struct ina3221_data - device specific information
 * @pm_dev: Device pointer for pm runtime
 * @regmap: Register map of the device
 * @fields: Register fields of the device
 * @inputs: Array of channel input source specific structures
 * @lock: mutex lock to serialize sysfs attribute accesses
 * @debugfs: Pointer to debugfs entry for device
 * @reg_config: Register value of INA3221_CONFIG
 * @summation_shunt_resistor: equivalent shunt resistor value for summation
 * @summation_channel_control: Value written to SCC field in INA3221_MASK_ENABLE
 * @single_shot: running in single-shot operating mode
 */
struct ina3221_data {
	struct device *pm_dev;
	struct regmap *regmap;
	struct regmap_field *fields[F_MAX_FIELDS];
	struct ina3221_input inputs[INA3221_NUM_CHANNELS];
	struct mutex lock;
	struct dentry *debugfs;
	u32 reg_config;
	int summation_shunt_resistor;
	u32 summation_channel_control;

	bool single_shot;
};

static inline bool ina3221_is_enabled(struct ina3221_data *ina, int channel)
{
	/* Summation channel checks shunt resistor values */
	if (channel > INA3221_CHANNEL3)
		return ina->summation_shunt_resistor != 0;

	return pm_runtime_active(ina->pm_dev) &&
	       (ina->reg_config & INA3221_CONFIG_CHx_EN(channel));
}

/*
 * Helper function to return the resistor value for current summation.
 *
 * There is a condition to calculate current summation -- all the shunt
 * resistor values should be the same, so as to simply fit the formula:
 *     current summation = shunt voltage summation / shunt resistor
 *
 * Returns the equivalent shunt resistor value on success or 0 on failure
 */
static inline int ina3221_summation_shunt_resistor(struct ina3221_data *ina)
{
	struct ina3221_input *input = ina->inputs;
	int i, shunt_resistor = 0;

	for (i = 0; i < INA3221_NUM_CHANNELS; i++) {
		if (input[i].disconnected || !input[i].shunt_resistor ||
		    input[i].summation_disable)
			continue;
		if (!shunt_resistor) {
			/* Found the reference shunt resistor value */
			shunt_resistor = input[i].shunt_resistor;
		} else {
			/* No summation if resistor values are different */
			if (shunt_