drivers/hwmon/tps23861.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (c) 2020 Sartura Ltd.
  *
  * Driver for the TI TPS23861 PoE PSE.
  *
  * Author: Robert Marko <robert.marko@sartura.hr>
  */

 #include <linux/bitfield.h>
 #include <linux/debugfs.h>
 #include <linux/delay.h>
 #include <linux/hwmon-sysfs.h>
 #include <linux/hwmon.h>
 #include <linux/i2c.h>
 #include <linux/module.h>
 #include <linux/of_device.h>
 #include <linux/regmap.h>

 #define TEMPERATURE			0x2c
 #define INPUT_VOLTAGE_LSB		0x2e
 #define INPUT_VOLTAGE_MSB		0x2f
 #define PORT_1_CURRENT_LSB		0x30
 #define PORT_1_CURRENT_MSB		0x31
 #define PORT_1_VOLTAGE_LSB		0x32
 #define PORT_1_VOLTAGE_MSB		0x33
 #define PORT_2_CURRENT_LSB		0x34
 #define PORT_2_CURRENT_MSB		0x35
 #define PORT_2_VOLTAGE_LSB		0x36
 #define PORT_2_VOLTAGE_MSB		0x37
 #define PORT_3_CURRENT_LSB		0x38
 #define PORT_3_CURRENT_MSB		0x39
 #define PORT_3_VOLTAGE_LSB		0x3a
 #define PORT_3_VOLTAGE_MSB		0x3b
 #define PORT_4_CURRENT_LSB		0x3c
 #define PORT_4_CURRENT_MSB		0x3d
 #define PORT_4_VOLTAGE_LSB		0x3e
 #define PORT_4_VOLTAGE_MSB		0x3f
 #define PORT_N_CURRENT_LSB_OFFSET	0x04
 #define PORT_N_VOLTAGE_LSB_OFFSET	0x04
 #define VOLTAGE_CURRENT_MASK		GENMASK(13, 0)
 #define PORT_1_RESISTANCE_LSB		0x60
 #define PORT_1_RESISTANCE_MSB		0x61
 #define PORT_2_RESISTANCE_LSB		0x62
 #define PORT_2_RESISTANCE_MSB		0x63
 #define PORT_3_RESISTANCE_LSB		0x64
 #define PORT_3_RESISTANCE_MSB		0x65
 #define PORT_4_RESISTANCE_LSB		0x66
 #define PORT_4_RESISTANCE_MSB		0x67
 #define PORT_N_RESISTANCE_LSB_OFFSET	0x02
 #define PORT_RESISTANCE_MASK		GENMASK(13, 0)
 #define PORT_RESISTANCE_RSN_MASK	GENMASK(15, 14)
 #define PORT_RESISTANCE_RSN_OTHER	0
 #define PORT_RESISTANCE_RSN_LOW		1
 #define PORT_RESISTANCE_RSN_OPEN	2
 #define PORT_RESISTANCE_RSN_SHORT	3
 #define PORT_1_STATUS			0x0c
 #define PORT_2_STATUS			0x0d
 #define PORT_3_STATUS			0x0e
 #define PORT_4_STATUS			0x0f
 #define PORT_STATUS_CLASS_MASK		GENMASK(7, 4)
 #define PORT_STATUS_DETECT_MASK		GENMASK(3, 0)
 #define PORT_CLASS_UNKNOWN		0
 #define PORT_CLASS_1			1
 #define PORT_CLASS_2			2
 #define PORT_CLASS_3			3
 #define PORT_CLASS_4			4
 #define PORT_CLASS_RESERVED		5
 #define PORT_CLASS_0			6
 #define PORT_CLASS_OVERCURRENT		7
 #define PORT_CLASS_MISMATCH		8
 #define PORT_DETECT_UNKNOWN		0
 #define PORT_DETECT_SHORT		1
 #define PORT_DETECT_RESERVED		2
 #define PORT_DETECT_RESISTANCE_LOW	3
 #define PORT_DETECT_RESISTANCE_OK	4
 #define PORT_DETECT_RESISTANCE_HIGH	5
 #define PORT_DETECT_OPEN_CIRCUIT	6
 #define PORT_DETECT_RESERVED_2		7
 #define PORT_DETECT_MOSFET_FAULT	8
 #define PORT_DETECT_LEGACY		9
 /* Measurment beyond clamp voltage */
 #define PORT_DETECT_CAPACITANCE_INVALID_BEYOND	10
 /* Insufficient voltage delta */
 #define PORT_DETECT_CAPACITANCE_INVALID_DELTA	11
 #define PORT_DETECT_CAPACITANCE_OUT_OF_RANGE	12
 #define POE_PLUS			0x40
 #define OPERATING_MODE			0x12
 #define OPERATING_MODE_OFF		0
 #define OPERATING_MODE_MANUAL		1
 #define OPERATING_MODE_SEMI		2
 #define OPERATING_MODE_AUTO		3
 #define OPERATING_MODE_PORT_1_MASK	GENMASK(1, 0)
 #define OPERATING_MODE_PORT_2_MASK	GENMASK(3, 2)
 #define OPERATING_MODE_PORT_3_MASK	GENMASK(5, 4)
 #define OPERATING_MODE_PORT_4_MASK	GENMASK(7, 6)

 #define DETECT_CLASS_RESTART		0x18
 #define POWER_ENABLE			0x19
 #define TPS23861_NUM_PORTS		4

 #define TPS23861_GENERAL_MASK_1		0x17
 #define TPS23861_CURRENT_SHUNT_MASK	BIT(0)

 #define TEMPERATURE_LSB			652 /* 0.652 degrees Celsius */
 #define VOLTAGE_LSB			3662 /* 3.662 mV */
 #define SHUNT_RESISTOR_DEFAULT		255000 /* 255 mOhm */
 #define CURRENT_LSB_250			62260 /* 62.260 uA */
 #define CURRENT_LSB_255			61039 /* 61.039 uA */
 #define RESISTANCE_LSB			110966 /* 11.0966 Ohm*/
 #define RESISTANCE_LSB_LOW		157216 /* 15.7216 Ohm*/

 struct tps23861_data {
 	struct regmap *regmap;
 	u32 shunt_resistor;
 	struct i2c_client *client;
 	struct dentry *debugfs_dir;
 };

 static struct regmap_config tps23861_regmap_config = {
 	.reg_bits = 8,
 	.val_bits = 8,
 	.max_register = 0x6f,
 };

 static int tps23861_read_temp(struct tps23861_data *data, long *val)
 {
 	unsigned int regval;
 	int err;

 	err = regmap_read(data->regmap, TEMPERATURE, &regval);
 	if (err < 0)
 		return err;

 	*val = (regval * TEMPERATURE_LSB) - 20000;

 	return 0;
 }

 static int tps23861_read_voltage(struct tps23861_data *data, int channel,
 				 long *val)
 {
 	__le16 regval;
 	long raw_val;
 	int err;

 	if (channel < TPS23861_NUM_PORTS) {
 		err = regmap_bulk_read(data->regmap,
 				       PORT_1_VOLTAGE_LSB + channel * PORT_N_VOLTAGE_LSB_OFFSET,
 				       &regval, 2);
 	} else {
 		err = regmap_bulk_read(data->regmap,
 				       INPUT_VOLTAGE_LSB,
 				       &regval, 2);
 	}
 	if (err < 0)
 		return err;

 	raw_val = le16_to_cpu(regval);
 	*val = (FIELD_GET(VOLTAGE_CURRENT_MASK, raw_val) * VOLTAGE_LSB) / 1000;

 	return 0;
 }

 static int tps23861_read_current(struct tps23861_data *data, int channel,
 				 long *val)
 {
 	long raw_val, current_lsb;
 	__le16 regval;

 	int err;

 	if (data->shunt_resistor == SHUNT_RESISTOR_DEFAULT)
 		current_lsb = CURRENT_LSB_255;
 	else
 		current_lsb = CURRENT_LSB_250;

 	err = regmap_bulk_read(data->regmap,
 			       PORT_1_CURRENT_LSB + channel * PORT_N_CURRENT_LSB_OFFSET,
 			       &regval, 2);
 	if (err < 0)
 		return err;

 	raw_val = le16_to_cpu(regval);
 	*val = (FIELD_GET(VOLTAGE_CURRENT_MASK, raw_val) * current_lsb) / 1000000;

 	return 0;
 }

 static int tps23861_port_disable(struct tps23861_data *data, int channel)
 {
 	unsigned int regval = 0;
 	int err;

 	regval |= BIT(channel + 4);
 	err = regmap_write(data->regmap, POWER_ENABLE, regval);

 	return err;
 }

 static int tps23861_port_enable(struct tps23861_data *data, int channel)
 {
 	unsigned int regval = 0;
 	int err;

 	regval |= BIT(channel);
 	regval |= BIT(channel + 4);
 	err = regmap_write(data->regmap, DETECT_CLASS_RESTART, regval);

 	return err;
 }

 static umode_t tps23861_is_visible(const void *data, enum hwmon_sensor_types type,
 				   u32 attr, int channel)
 {
 	switch (type) {
 	case hwmon_temp:
 		switch (attr) {
 		case hwmon_temp_input:
 		case hwmon_temp_label:
 			return 0444;
 		default:
 			return 0;
 		}
 	case hwmon_in:
 		switch (attr) {
 		case hwmon_in_input:
 		case hwmon_in_label:
 			return 0444;
 		case hwmon_in_enable:
 			return 0200;
 		default:
 			return 0;
 		}
 	case hwmon_curr:
 		switch (attr) {
 		case hwmon_curr_input:
 		case hwmon_curr_label:
 			return 0444;
 		default:
 			return 0;
 		}
 	default:
 		return 0;
 	}
 }

 static int tps23861_write(struct device *dev, enum hwmon_sensor_types type,
 			  u32 attr, int channel, long val)
 {
 	struct tps23861_data *data = dev_get_drvdata(dev);
 	int err;

 	switch (type) {
 	case hwmon_in:
 		switch (attr) {
 		case hwmon_in_enable:
 			if (val == 0)
 				err = tps23861_port_disable(data, channel);
 			else if (val == 1)
 				err = tps23861_port_enable(data, channel);
 			else
 				err = -EINVAL;
 			break;
 		default:
 			return -EOPNOTSUPP;
 		}
 		break;
 	default:
 		return -EOPNOTSUPP;
 	}

 	return err;
 }

 static int tps23861_read(struct device *dev, enum hwmon_sensor_types type,
 			 u32 attr, int channel, long *val)
 {
 	struct tps23861_data *data = dev_get_drvdata(dev);
 	int err;

 	switch (type) {
 	case hwmon_temp:
 		switch (attr) {
 		case hwmon_temp_input:
 			err = tps23861_read_temp(data, val);
 			break;
 		default:
 			return -EOPNOTSUPP;
 		}
 		break;
 	case hwmon_in:
 		switch (attr) {
 		case hwmon_in_input:
 			err = tps23861_read_voltage(data, channel, val);
 			break;
 		default:
 			return -EOPNOTSUPP;
 		}
 		break;
 	case hwmon_curr:
 		switch (attr) {
 		case hwmon_curr_input:
 			err = tps23861_read_current(data, channel, val);
 			break;
 		default:
 			return -EOPNOTSUPP;
 		}
 		break;
 	default:
 		return -EOPNOTSUPP;
 	}

 	return err;
 }

 static const char * const tps23861_port_label[] = {
 	"Port1",
 	"Port2",
 	"Port3",
 	"Port4",
 	"Input",
 };

 static int tps23861_read_string(struct device *dev,
 				enum hwmon_sensor_types type,
 				u32 attr, int channel, const char **str)
 {
 	switch (type) {
 	case hwmon_in:
 	case hwmon_curr:
 		*str = tps23861_port_label[channel];
 		break;
 	case hwmon_temp:
 		*str = "Die";
 		break;
 	default:
 		return -EOPNOTSUPP;
 	}

 	return 0;
 }

 static const struct hwmon_channel_info *tps23861_info[] = {
 	HWMON_CHANNEL_INFO(chip,
 			   HWMON_C_REGISTER_TZ),
 	HWMON_CHANNEL_INFO(temp,
 			   HWMON_T_INPUT | HWMON_T_LABEL),
 	HWMON_CHANNEL_INFO(in,
 			   HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
 			   HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
 			   HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
 			   HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
 			   HWMON_I_INPUT | HWMON_I_LABEL),
 	HWMON_CHANNEL_INFO(curr,
 			   HWMON_C_INPUT | HWMON_C_LABEL,
 			   HWMON_C_INPUT | HWMON_C_LABEL,
 			   HWMON_C_INPUT | HWMON_C_LABEL,
 			   HWMON_C_INPUT | HWMON_C_LABEL),
 	NULL
 };

 static const struct hwmon_ops tps23861_hwmon_ops = {
 	.is_visible = tps23861_is_visible,
 	.write = tps23861_write,
 	.read = tps23861_read,
 	.read_string = tps23861_read_string,
 };

 static const struct hwmon_chip_info tps23861_chip_info = {
 	.ops = &tps23861_hwmon_ops,
 	.info = tps23861_info,
 };

 static char *port_operating_mode_string(uint8_t mode_reg, unsigned int port)
 {
 	unsigned int mode = ~0;

 	if (port < TPS23861_NUM_PORTS)
 		mode = (mode_reg >> (2 * port)) & OPERATING_MODE_PORT_1_MASK;

 	switch (mode) {
 	case OPERATING_MODE_OFF:
 		return "Off";
 	case OPERATING_MODE_MANUAL:
 		return "Manual";
 	case OPERATING_MODE_SEMI:
 		return "Semi-Auto";
 	case OPERATING_MODE_AUTO:
 		return "Auto";
 	default:
 		return "Invalid";
 	}
 }

 static char *port_detect_status_string(uint8_t status_reg)
 {
 	switch (FIELD_GET(PORT_STATUS_DETECT_MASK, status_reg)) {
 	case PORT_DETECT_UNKNOWN:
 		return "Unknown device";
 	case PORT_DETECT_SHORT:
 		return "Short circuit";
 	case PORT_DETECT_RESISTANCE_LOW:
 		return "Too low resistance";
 	case PORT_DETECT_RESISTANCE_OK:
 		return "Valid resistance";
 	case PORT_DETECT_RESISTANCE_HIGH:
 		return "Too high resistance";
 	case PORT_DETECT_OPEN_CIRCUIT:
 		return "Open circuit";
 	case PORT_DETECT_MOSFET_FAULT:
 		return "MOSFET fault";
 	case PORT_DETECT_LEGACY:
 		return "Legacy device";
 	case PORT_DETECT_CAPACITANCE_INVALID_BEYOND:
 		return "Invalid capacitance, beyond clamp voltage";
 	case PORT_DETECT_CAPACITANCE_INVALID_DELTA:
 		return "Invalid capacitance, insufficient voltage delta";
 	case PORT_DETECT_CAPACITANCE_OUT_OF_RANGE:
 		return "Valid capacitance, outside of legacy range";
 	case PORT_DETECT_RESERVED:
 	case PORT_DETECT_RESERVED_2:
 	default:
 		return "Invalid";
 	}
 }

 static char *port_class_status_string(uint8_t status_reg)
 {
 	switch (FIELD_GET(PORT_STATUS_CLASS_MASK, status_reg)) {
 	case PORT_CLASS_UNKNOWN:
 		return "Unknown";
 	case PORT_CLASS_RESERVED:
 	case PORT_CLASS_0:
 		return "0";
 	case PORT_CLASS_1:
 		return "1";
 	case PORT_CLASS_2:
 		return "2";
 	case PORT_CLASS_3:
 		return "3";
 	case PORT_CLASS_4:
 		return "4";
 	case PORT_CLASS_OVERCURRENT:
 		return "Overcurrent";
 	case PORT_CLASS_MISMATCH:
 		return "Mismatch";
 	default:
 		return "Invalid";
 	}
 }

 static char *port_poe_plus_status_string(uint8_t poe_plus, unsigned int port)
 {
 	return (BIT(port + 4) & poe_plus) ? "Yes" : "No";
 }

 static int tps23861_port_resistance(struct tps23861_data *data, int port)
 {
 	unsigned int raw_val;
 	__le16 regval;

 	regmap_bulk_read(data->regmap,
 			 PORT_1_RESISTANCE_LSB + PORT_N_RESISTANCE_LSB_OFFSET * port,
 			 &regval,
 			 2);

 	raw_val = le16_to_cpu(regval);
 	switch (FIELD_GET(PORT_RESISTANCE_RSN_MASK, raw_val)) {
 	case PORT_RESISTANCE_RSN_OTHER:
 		return (FIELD_GET(PORT_RESISTANCE_MASK, raw_val) * RESISTANCE_LSB) / 10000;
 	case PORT_RESISTANCE_RSN_LOW:
 		return (FIELD_GET(PORT_RESISTANCE_MASK, raw_val) * RESISTANCE_LSB_LOW) / 10000;
 	case PORT_RESISTANCE_RSN_SHORT:
 	case PORT_RESISTANCE_RSN_OPEN:
 	default:
 		return 0;
 	}
 }

 static int tps23861_port_status_show(struct seq_file *s, void *data)
 {
 	struct tps23861_data *priv = s->private;
 	unsigned int i, mode, poe_plus, status;

 	regmap_read(priv->regmap, OPERATING_MODE, &mode);
 	regmap_read(priv->regmap, POE_PLUS, &poe_plus);

 	for (i = 0; i < TPS23861_NUM_PORTS; i++) {
 		regmap_read(priv->regmap, PORT_1_STATUS + i, &status);

 		seq_printf(s, "Port: \t\t%d\n", i + 1);
 		seq_printf(s, "Operating mode: %s\n", port_operating_mode_string(mode, i));
 		seq_printf(s, "Detected: \t%s\n", port_detect_status_string(status));
 		seq_printf(s, "Class: \t\t%s\n", port_class_status_string(status));
 		seq_printf(s, "PoE Plus: \t%s\n", port_poe_plus_status_string(poe_plus, i));
 		seq_printf(s, "Resistance: \t%d\n", tps23861_port_resistance(priv, i));
 		seq_putc(s, '\n');
 	}

 	return 0;
 }

 DEFINE_SHOW_ATTRIBUTE(tps23861_port_status);

 static void tps23861_init_debugfs(struct tps23861_data *data,
 				  struct device *hwmon_dev)
 {
 	const char *debugfs_name;

 	debugfs_name = devm_kasprintf(&data->client->dev, GFP_KERNEL, "%s-%s",
 				      data->client->name, dev_name(hwmon_dev));
 	if (!debugfs_name)
 		return;

 	data->debugfs_dir = debugfs_create_dir(debugfs_name, NULL);

 	debugfs_create_file("port_status",
 			    0400,
 			    data->debugfs_dir,
 			    data,
 			    &tps23861_port_status_fops);
 }

 static int tps23861_probe(struct i2c_client *client)
 {
 	struct device *dev = &client->dev;
 	struct tps23861_data *data;
 	struct device *hwmon_dev;
 	u32 shunt_resistor;

 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;

 	data->client = client;
 	i2c_set_clientdata(client, data);

 	data->regmap = devm_regmap_init_i2c(client, &tps23861_regmap_config);
 	if (IS_ERR(data->regmap)) {
 		dev_err(dev, "failed to allocate register map\n");
 		return PTR_ERR(data->regmap);
 	}

 	if (!of_property_read_u32(dev->of_node, "shunt-resistor-micro-ohms", &shunt_resistor))
 		data->shunt_resistor = shunt_resistor;
 	else
 		data->shunt_resistor = SHUNT_RESISTOR_DEFAULT;

 	if (data->shunt_resistor == SHUNT_RESISTOR_DEFAULT)
 		regmap_clear_bits(data->regmap,
 				  TPS23861_GENERAL_MASK_1,
 				  TPS23861_CURRENT_SHUNT_MASK);
 	else
 		regmap_set_bits(data->regmap,
 				TPS23861_GENERAL_MASK_1,
 				TPS23861_CURRENT_SHUNT_MASK);

 	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
 							 data, &tps23861_chip_info,
 							 NULL);
 	if (IS_ERR(hwmon_dev))
 		return PTR_ERR(hwmon_dev);

 	tps23861_init_debugfs(data, hwmon_dev);

 	return 0;
 }

 static void tps23861_remove(struct i2c_client *client)
 {
 	struct tps23861_data *data = i2c_get_clientdata(client);

 	debugfs_remove_recursive(data->debugfs_dir);
 }

 static const struct of_device_id __maybe_unused tps23861_of_match[] = {
 	{ .compatible = "ti,tps23861", },
 	{ },
 };
 MODULE_DEVICE_TABLE(of, tps23861_of_match);

 static struct i2c_driver tps23861_driver = {
 	.probe_new		= tps23861_probe,
 	.remove			= tps23861_remove,
 	.driver = {
 		.name		= "tps23861",
 		.of_match_table	= of_match_ptr(tps23861_of_match),
 	},
 };
 module_i2c_driver(tps23861_driver);

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Robert Marko <robert.marko@sartura.hr>");
 MODULE_DESCRIPTION("TI TPS23861 PoE PSE");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Copyright (c) 2020 Sartura Ltd.
	*
	* Driver for the TI TPS23861 PoE PSE.
	*
	* Author: Robert Marko <robert.marko@sartura.hr>
	*/

	#include <linux/bitfield.h>
	#include <linux/debugfs.h>
	#include <linux/delay.h>
	#include <linux/hwmon-sysfs.h>
	#include <linux/hwmon.h>
	#include <linux/i2c.h>
	#include <linux/module.h>
	#include <linux/of_device.h>
	#include <linux/regmap.h>

	#define TEMPERATURE 0x2c
	#define INPUT_VOLTAGE_LSB 0x2e
	#define INPUT_VOLTAGE_MSB 0x2f
	#define PORT_1_CURRENT_LSB 0x30
	#define PORT_1_CURRENT_MSB 0x31
	#define PORT_1_VOLTAGE_LSB 0x32
	#define PORT_1_VOLTAGE_MSB 0x33
	#define PORT_2_CURRENT_LSB 0x34
	#define PORT_2_CURRENT_MSB 0x35
	#define PORT_2_VOLTAGE_LSB 0x36
	#define PORT_2_VOLTAGE_MSB 0x37
	#define PORT_3_CURRENT_LSB 0x38
	#define PORT_3_CURRENT_MSB 0x39
	#define PORT_3_VOLTAGE_LSB 0x3a
	#define PORT_3_VOLTAGE_MSB 0x3b
	#define PORT_4_CURRENT_LSB 0x3c
	#define PORT_4_CURRENT_MSB 0x3d
	#define PORT_4_VOLTAGE_LSB 0x3e
	#define PORT_4_VOLTAGE_MSB 0x3f
	#define PORT_N_CURRENT_LSB_OFFSET 0x04
	#define PORT_N_VOLTAGE_LSB_OFFSET 0x04
	#define VOLTAGE_CURRENT_MASK GENMASK(13, 0)
	#define PORT_1_RESISTANCE_LSB 0x60
	#define PORT_1_RESISTANCE_MSB 0x61
	#define PORT_2_RESISTANCE_LSB 0x62
	#define PORT_2_RESISTANCE_MSB 0x63
	#define PORT_3_RESISTANCE_LSB 0x64
	#define PORT_3_RESISTANCE_MSB 0x65
	#define PORT_4_RESISTANCE_LSB 0x66
	#define PORT_4_RESISTANCE_MSB 0x67
	#define PORT_N_RESISTANCE_LSB_OFFSET 0x02
	#define PORT_RESISTANCE_MASK GENMASK(13, 0)
	#define PORT_RESISTANCE_RSN_MASK GENMASK(15, 14)
	#define PORT_RESISTANCE_RSN_OTHER 0
	#define PORT_RESISTANCE_RSN_LOW 1
	#define PORT_RESISTANCE_RSN_OPEN 2
	#define PORT_RESISTANCE_RSN_SHORT 3
	#define PORT_1_STATUS 0x0c
	#define PORT_2_STATUS 0x0d
	#define PORT_3_STATUS 0x0e
	#define PORT_4_STATUS 0x0f
	#define PORT_STATUS_CLASS_MASK GENMASK(7, 4)
	#define PORT_STATUS_DETECT_MASK GENMASK(3, 0)
	#define PORT_CLASS_UNKNOWN 0
	#define PORT_CLASS_1 1
	#define PORT_CLASS_2 2
	#define PORT_CLASS_3 3
	#define PORT_CLASS_4 4
	#define PORT_CLASS_RESERVED 5
	#define PORT_CLASS_0 6
	#define PORT_CLASS_OVERCURRENT 7
	#define PORT_CLASS_MISMATCH 8
	#define PORT_DETECT_UNKNOWN 0
	#define PORT_DETECT_SHORT 1
	#define PORT_DETECT_RESERVED 2
	#define PORT_DETECT_RESISTANCE_LOW 3
	#define PORT_DETECT_RESISTANCE_OK 4
	#define PORT_DETECT_RESISTANCE_HIGH 5
	#define PORT_DETECT_OPEN_CIRCUIT 6
	#define PORT_DETECT_RESERVED_2 7
	#define PORT_DETECT_MOSFET_FAULT 8
	#define PORT_DETECT_LEGACY 9
	/* Measurment beyond clamp voltage */
	#define PORT_DETECT_CAPACITANCE_INVALID_BEYOND 10
	/* Insufficient voltage delta */
	#define PORT_DETECT_CAPACITANCE_INVALID_DELTA 11
	#define PORT_DETECT_CAPACITANCE_OUT_OF_RANGE 12
	#define POE_PLUS 0x40
	#define OPERATING_MODE 0x12
	#define OPERATING_MODE_OFF 0
	#define OPERATING_MODE_MANUAL 1
	#define OPERATING_MODE_SEMI 2
	#define OPERATING_MODE_AUTO 3
	#define OPERATING_MODE_PORT_1_MASK GENMASK(1, 0)
	#define OPERATING_MODE_PORT_2_MASK GENMASK(3, 2)
	#define OPERATING_MODE_PORT_3_MASK GENMASK(5, 4)
	#define OPERATING_MODE_PORT_4_MASK GENMASK(7, 6)

	#define DETECT_CLASS_RESTART 0x18
	#define POWER_ENABLE 0x19
	#define TPS23861_NUM_PORTS 4

	#define TPS23861_GENERAL_MASK_1 0x17
	#define TPS23861_CURRENT_SHUNT_MASK BIT(0)

	#define TEMPERATURE_LSB 652 /* 0.652 degrees Celsius */
	#define VOLTAGE_LSB 3662 /* 3.662 mV */
	#define SHUNT_RESISTOR_DEFAULT 255000 /* 255 mOhm */
	#define CURRENT_LSB_250 62260 /* 62.260 uA */
	#define CURRENT_LSB_255 61039 /* 61.039 uA */
	#define RESISTANCE_LSB 110966 /* 11.0966 Ohm*/
	#define RESISTANCE_LSB_LOW 157216 /* 15.7216 Ohm*/

	struct tps23861_data {
	struct regmap *regmap;
	u32 shunt_resistor;
	struct i2c_client *client;
	struct dentry *debugfs_dir;
	};

	static struct regmap_config tps23861_regmap_config = {
	.reg_bits = 8,
	.val_bits = 8,
	.max_register = 0x6f,
	};

	static int tps23861_read_temp(struct tps23861_data data, long val)
	{
	unsigned int regval;
	int err;

	err = regmap_read(data->regmap, TEMPERATURE, &regval);
	if (err < 0)
	return err;

	val = (regval TEMPERATURE_LSB) - 20000;

	return 0;
	}

	static int tps23861_read_voltage(struct tps23861_data *data, int channel,
	long *val)
	{
	__le16 regval;
	long raw_val;
	int err;

	if (channel < TPS23861_NUM_PORTS) {
	err = regmap_bulk_read(data->regmap,
	PORT_1_VOLTAGE_LSB + channel * PORT_N_VOLTAGE_LSB_OFFSET,
	&regval, 2);
	} else {
	err = regmap_bulk_read(data->regmap,
	INPUT_VOLTAGE_LSB,
	&regval, 2);
	}
	if (err < 0)
	return err;

	raw_val = le16_to_cpu(regval);
	val = (FIELD_GET(VOLTAGE_CURRENT_MASK, raw_val) VOLTAGE_LSB) / 1000;

	return 0;
	}

	static int tps23861_read_current(struct tps23861_data *data, int channel,
	long *val)
	{
	long raw_val, current_lsb;
	__le16 regval;

	int err;

	if (data->shunt_resistor == SHUNT_RESISTOR_DEFAULT)
	current_lsb = CURRENT_LSB_255;
	else
	current_lsb = CURRENT_LSB_250;

	err = regmap_bulk_read(data->regmap,
	PORT_1_CURRENT_LSB + channel * PORT_N_CURRENT_LSB_OFFSET,
	&regval, 2);
	if (err < 0)
	return err;

	raw_val = le16_to_cpu(regval);
	val = (FIELD_GET(VOLTAGE_CURRENT_MASK, raw_val) current_lsb) / 1000000;

	return 0;
	}

	static int tps23861_port_disable(struct tps23861_data *data, int channel)
	{
	unsigned int regval = 0;
	int err;

	regval \|= BIT(channel + 4);
	err = regmap_write(data->regmap, POWER_ENABLE, regval);

	return err;
	}

	static int tps23861_port_enable(struct tps23861_data *data, int channel)
	{
	unsigned int regval = 0;
	int err;

	regval \|= BIT(channel);
	regval \|= BIT(channel + 4);
	err = regmap_write(data->regmap, DETECT_CLASS_RESTART, regval);

	return err;
	}

	static umode_t tps23861_is_visible(const void *data, enum hwmon_sensor_types type,
	u32 attr, int channel)
	{
	switch (type) {
	case hwmon_temp:
	switch (attr) {
	case hwmon_temp_input:
	case hwmon_temp_label:
	return 0444;
	default:
	return 0;
	}
	case hwmon_in:
	switch (attr) {
	case hwmon_in_input:
	case hwmon_in_label:
	return 0444;
	case hwmon_in_enable:
	return 0200;
	default:
	return 0;
	}
	case hwmon_curr:
	switch (attr) {
	case hwmon_curr_input:
	case hwmon_curr_label:
	return 0444;
	default:
	return 0;
	}
	default:
	return 0;
	}
	}

	static int tps23861_write(struct device *dev, enum hwmon_sensor_types type,
	u32 attr, int channel, long val)
	{
	struct tps23861_data *data = dev_get_drvdata(dev);
	int err;

	switch (type) {
	case hwmon_in:
	switch (attr) {
	case hwmon_in_enable:
	if (val == 0)
	err = tps23861_port_disable(data, channel);
	else if (val == 1)
	err = tps23861_port_enable(data, channel);
	else
	err = -EINVAL;
	break;
	default:
	return -EOPNOTSUPP;
	}
	break;
	default:
	return -EOPNOTSUPP;
	}

	return err;
	}

	static int tps23861_read(struct device *dev, enum hwmon_sensor_types type,
	u32 attr, int channel, long *val)
	{
	struct tps23861_data *data = dev_get_drvdata(dev);
	int err;

	switch (type) {
	case hwmon_temp:
	switch (attr) {
	case hwmon_temp_input:
	err = tps23861_read_temp(data, val);
	break;
	default:
	return -EOPNOTSUPP;
	}
	break;
	case hwmon_in:
	switch (attr) {
	case hwmon_in_input:
	err = tps23861_read_voltage(data, channel, val);
	break;
	default:
	return -EOPNOTSUPP;
	}
	break;
	case hwmon_curr:
	switch (attr) {
	case hwmon_curr_input:
	err = tps23861_read_current(data, channel, val);
	break;
	default:
	return -EOPNOTSUPP;
	}
	break;
	default:
	return -EOPNOTSUPP;
	}

	return err;
	}

	static const char * const tps23861_port_label[] = {
	"Port1",
	"Port2",
	"Port3",
	"Port4",
	"Input",
	};

	static int tps23861_read_string(struct device *dev,
	enum hwmon_sensor_types type,
	u32 attr, int channel, const char **str)
	{
	switch (type) {
	case hwmon_in:
	case hwmon_curr:
	*str = tps23861_port_label[channel];
	break;
	case hwmon_temp:
	*str = "Die";
	break;
	default:
	return -EOPNOTSUPP;
	}

	return 0;
	}

	static const struct hwmon_channel_info *tps23861_info[] = {
	HWMON_CHANNEL_INFO(chip,
	HWMON_C_REGISTER_TZ),
	HWMON_CHANNEL_INFO(temp,
	HWMON_T_INPUT \| HWMON_T_LABEL),
	HWMON_CHANNEL_INFO(in,
	HWMON_I_INPUT \| HWMON_I_ENABLE \| HWMON_I_LABEL,
	HWMON_I_INPUT \| HWMON_I_ENABLE \| HWMON_I_LABEL,
	HWMON_I_INPUT \| HWMON_I_ENABLE \| HWMON_I_LABEL,
	HWMON_I_INPUT \| HWMON_I_ENABLE \| HWMON_I_LABEL,
	HWMON_I_INPUT \| HWMON_I_LABEL),
	HWMON_CHANNEL_INFO(curr,
	HWMON_C_INPUT \| HWMON_C_LABEL,
	HWMON_C_INPUT \| HWMON_C_LABEL,
	HWMON_C_INPUT \| HWMON_C_LABEL,
	HWMON_C_INPUT \| HWMON_C_LABEL),
	NULL
	};

	static const struct hwmon_ops tps23861_hwmon_ops = {
	.is_visible = tps23861_is_visible,
	.write = tps23861_write,
	.read = tps23861_read,
	.read_string = tps23861_read_string,
	};

	static const struct hwmon_chip_info tps23861_chip_info = {
	.ops = &tps23861_hwmon_ops,
	.info = tps23861_info,
	};

	static char *port_operating_mode_string(uint8_t mode_reg, unsigned int port)
	{
	unsigned int mode = ~0;

	if (port < TPS23861_NUM_PORTS)
	mode = (mode_reg >> (2 * port)) & OPERATING_MODE_PORT_1_MASK;

	switch (mode) {
	case OPERATING_MODE_OFF:
	return "Off";
	case OPERATING_MODE_MANUAL:
	return "Manual";
	case OPERATING_MODE_SEMI:
	return "Semi-Auto";
	case OPERATING_MODE_AUTO:
	return "Auto";
	default:
	return "Invalid";
	}
	}

	static char *port_detect_status_string(uint8_t status_reg)
	{
	switch (FIELD_GET(PORT_STATUS_DETECT_MASK, status_reg)) {
	case PORT_DETECT_UNKNOWN:
	return "Unknown device";
	case PORT_DETECT_SHORT:
	return "Short circuit";
	case PORT_DETECT_RESISTANCE_LOW:
	return "Too low resistance";
	case PORT_DETECT_RESISTANCE_OK:
	return "Valid resistance";
	case PORT_DETECT_RESISTANCE_HIGH:
	return "Too high resistance";
	case PORT_DETECT_OPEN_CIRCUIT:
	return "Open circuit";
	case PORT_DETECT_MOSFET_FAULT:
	return "MOSFET fault";
	case PORT_DETECT_LEGACY:
	return "Legacy device";
	case PORT_DETECT_CAPACITANCE_INVALID_BEYOND:
	return "Invalid capacitance, beyond clamp voltage";
	case PORT_DETECT_CAPACITANCE_INVALID_DELTA:
	return "Invalid capacitance, insufficient voltage delta";
	case PORT_DETECT_CAPACITANCE_OUT_OF_RANGE:
	return "Valid capacitance, outside of legacy range";
	case PORT_DETECT_RESERVED:
	case PORT_DETECT_RESERVED_2:
	default:
	return "Invalid";
	}
	}

	static char *port_class_status_string(uint8_t status_reg)
	{
	switch (FIELD_GET(PORT_STATUS_CLASS_MASK, status_reg)) {
	case PORT_CLASS_UNKNOWN:
	return "Unknown";
	case PORT_CLASS_RESERVED:
	case PORT_CLASS_0:
	return "0";
	case PORT_CLASS_1:
	return "1";
	case PORT_CLASS_2:
	return "2";
	case PORT_CLASS_3:
	return "3";
	case PORT_CLASS_4:
	return "4";
	case PORT_CLASS_OVERCURRENT:
	return "Overcurrent";
	case PORT_CLASS_MISMATCH:
	return "Mismatch";
	default:
	return "Invalid";
	}
	}

	static char *port_poe_plus_status_string(uint8_t poe_plus, unsigned int port)
	{
	return (BIT(port + 4) & poe_plus) ? "Yes" : "No";
	}

	static int tps23861_port_resistance(struct tps23861_data *data, int port)
	{
	unsigned int raw_val;
	__le16 regval;

	regmap_bulk_read(data->regmap,
	PORT_1_RESISTANCE_LSB + PORT_N_RESISTANCE_LSB_OFFSET * port,
	&regval,
	2);

	raw_val = le16_to_cpu(regval);
	switch (FIELD_GET(PORT_RESISTANCE_RSN_MASK, raw_val)) {
	case PORT_RESISTANCE_RSN_OTHER:
	return (FIELD_GET(PORT_RESISTANCE_MASK, raw_val) * RESISTANCE_LSB) / 10000;
	case PORT_RESISTANCE_RSN_LOW:
	return (FIELD_GET(PORT_RESISTANCE_MASK, raw_val) * RESISTANCE_LSB_LOW) / 10000;
	case PORT_RESISTANCE_RSN_SHORT:
	case PORT_RESISTANCE_RSN_OPEN:
	default:
	return 0;
	}
	}

	static int tps23861_port_status_show(struct seq_file s, void data)
	{
	struct tps23861_data *priv = s->private;
	unsigned int i, mode, poe_plus, status;

	regmap_read(priv->regmap, OPERATING_MODE, &mode);
	regmap_read(priv->regmap, POE_PLUS, &poe_plus);

	for (i = 0; i < TPS23861_NUM_PORTS; i++) {
	regmap_read(priv->regmap, PORT_1_STATUS + i, &status);

	seq_printf(s, "Port: \t\t%d\n", i + 1);
	seq_printf(s, "Operating mode: %s\n", port_operating_mode_string(mode, i));
	seq_printf(s, "Detected: \t%s\n", port_detect_status_string(status));
	seq_printf(s, "Class: \t\t%s\n", port_class_status_string(status));
	seq_printf(s, "PoE Plus: \t%s\n", port_poe_plus_status_string(poe_plus, i));
	seq_printf(s, "Resistance: \t%d\n", tps23861_port_resistance(priv, i));
	seq_putc(s, '\n');
	}

	return 0;
	}

	DEFINE_SHOW_ATTRIBUTE(tps23861_port_status);

	static void tps23861_init_debugfs(struct tps23861_data *data,
	struct device *hwmon_dev)
	{
	const char *debugfs_name;

	debugfs_name = devm_kasprintf(&data->client->dev, GFP_KERNEL, "%s-%s",
	data->client->name, dev_name(hwmon_dev));
	if (!debugfs_name)
	return;

	data->debugfs_dir = debugfs_create_dir(debugfs_name, NULL);

	debugfs_create_file("port_status",
	0400,
	data->debugfs_dir,
	data,
	&tps23861_port_status_fops);
	}

	static int tps23861_probe(struct i2c_client *client)
	{
	struct device *dev = &client->dev;
	struct tps23861_data *data;
	struct device *hwmon_dev;
	u32 shunt_resistor;

	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
	if (!data)
	return -ENOMEM;

	data->client = client;
	i2c_set_clientdata(client, data);

	data->regmap = devm_regmap_init_i2c(client, &tps23861_regmap_config);
	if (IS_ERR(data->regmap)) {
	dev_err(dev, "failed to allocate register map\n");
	return PTR_ERR(data->regmap);
	}

	if (!of_property_read_u32(dev->of_node, "shunt-resistor-micro-ohms", &shunt_resistor))
	data->shunt_resistor = shunt_resistor;
	else
	data->shunt_resistor = SHUNT_RESISTOR_DEFAULT;

	if (data->shunt_resistor == SHUNT_RESISTOR_DEFAULT)
	regmap_clear_bits(data->regmap,
	TPS23861_GENERAL_MASK_1,
	TPS23861_CURRENT_SHUNT_MASK);
	else
	regmap_set_bits(data->regmap,
	TPS23861_GENERAL_MASK_1,
	TPS23861_CURRENT_SHUNT_MASK);

	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
	data, &tps23861_chip_info,
	NULL);
	if (IS_ERR(hwmon_dev))
	return PTR_ERR(hwmon_dev);

	tps23861_init_debugfs(data, hwmon_dev);

	return 0;
	}

	static void tps23861_remove(struct i2c_client *client)
	{
	struct tps23861_data *data = i2c_get_clientdata(client);

	debugfs_remove_recursive(data->debugfs_dir);
	}

	static const struct of_device_id __maybe_unused tps23861_of_match[] = {
	{ .compatible = "ti,tps23861", },
	{ },
	};
	MODULE_DEVICE_TABLE(of, tps23861_of_match);

	static struct i2c_driver tps23861_driver = {
	.probe_new = tps23861_probe,
	.remove = tps23861_remove,
	.driver = {
	.name = "tps23861",
	.of_match_table = of_match_ptr(tps23861_of_match),
	},
	};
	module_i2c_driver(tps23861_driver);

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Robert Marko <robert.marko@sartura.hr>");
	MODULE_DESCRIPTION("TI TPS23861 PoE PSE");