Commit 09b08ac9 authored by Beniamin Bia's avatar Beniamin Bia Committed by Guenter Roeck
Browse files

hwmon: (adm1177) Add ADM1177 Hot Swap Controller and Digital Power Monitor driver 

ADM1177 is a Hot Swap Controller and Digital Power Monitor with
Soft Start Pin.

Datasheet:
Link: https://www.analog.com/media/en/technical-documentation/data-sheets/ADM1177.pdf



Signed-off-by: default avatarBeniamin Bia <beniamin.bia@analog.com>
Link: https://lore.kernel.org/r/20200114112159.25998-1-beniamin.bia@analog.com


Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent 971dfd8c

Documentation/hwmon/adm1177.rst

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Kernel driver adm1177

=====================



Supported chips:

  * Analog Devices ADM1177

    Prefix: 'adm1177'

    Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/ADM1177.pdf



Author: Beniamin Bia <beniamin.bia@analog.com>





Description

-----------



This driver supports hardware monitoring for Analog Devices ADM1177

Hot-Swap Controller and Digital Power Monitors with Soft Start Pin.





Usage Notes

-----------



This driver does not auto-detect devices. You will have to instantiate the

devices explicitly. Please see Documentation/i2c/instantiating-devices for

details.





Sysfs entries

-------------



The following attributes are supported. Current maxim attribute

is read-write, all other attributes are read-only.



in0_input		Measured voltage in microvolts.



curr1_input		Measured current in microamperes.

curr1_max_alarm		Overcurrent alarm in microamperes.

Documentation/hwmon/index.rst

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@@ -29,6 +29,7 @@ Hardware Monitoring Kernel Drivers 
   adm1025

   adm1026

   adm1031

   adm1177

   adm1275

   adm9240

   ads7828

drivers/hwmon/Kconfig

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@@ -164,6 +164,16 @@ config SENSORS_ADM1031 
	  This driver can also be built as a module. If so, the module

	  will be called adm1031.



config SENSORS_ADM1177

	tristate "Analog Devices ADM1177 and compatibles"

	depends on I2C

	help

	  If you say yes here you get support for Analog Devices ADM1177

	  sensor chips.



	  This driver can also be built as a module.  If so, the module

	  will be called adm1177.



config SENSORS_ADM9240

	tristate "Analog Devices ADM9240 and compatibles"

	depends on I2C

drivers/hwmon/Makefile

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@@ -34,6 +34,7 @@ obj-$(CONFIG_SENSORS_ADM1025) += adm1025.o 
obj-$(CONFIG_SENSORS_ADM1026)	+= adm1026.o

obj-$(CONFIG_SENSORS_ADM1029)	+= adm1029.o

obj-$(CONFIG_SENSORS_ADM1031)	+= adm1031.o

obj-$(CONFIG_SENSORS_ADM1177)	+= adm1177.o

obj-$(CONFIG_SENSORS_ADM9240)	+= adm9240.o

obj-$(CONFIG_SENSORS_ADS7828)	+= ads7828.o

obj-$(CONFIG_SENSORS_ADS7871)	+= ads7871.o

drivers/hwmon/adm1177.c

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// SPDX-License-Identifier: GPL-2.0

/*

 * ADM1177 Hot Swap Controller and Digital Power Monitor with Soft Start Pin

 *

 * Copyright 2015-2019 Analog Devices Inc.

 */



#include <linux/bits.h>

#include <linux/device.h>

#include <linux/hwmon.h>

#include <linux/i2c.h>

#include <linux/init.h>

#include <linux/module.h>

#include <linux/regulator/consumer.h>



/*  Command Byte Operations */

#define ADM1177_CMD_V_CONT	BIT(0)

#define ADM1177_CMD_I_CONT	BIT(2)

#define ADM1177_CMD_VRANGE	BIT(4)



/* Extended Register */

#define ADM1177_REG_ALERT_TH	2



#define ADM1177_BITS		12



/**

 * struct adm1177_state - driver instance specific data

 * @client		pointer to i2c client

 * @reg			regulator info for the the power supply of the device

 * @r_sense_uohm	current sense resistor value

 * @alert_threshold_ua	current limit for shutdown

 * @vrange_high		internal voltage divider

 */

struct adm1177_state {

	struct i2c_client	*client;

	struct regulator	*reg;

	u32			r_sense_uohm;

	u32			alert_threshold_ua;

	bool			vrange_high;

};



static int adm1177_read_raw(struct adm1177_state *st, u8 num, u8 *data)

{

	return i2c_master_recv(st->client, data, num);

}



static int adm1177_write_cmd(struct adm1177_state *st, u8 cmd)

{

	return i2c_smbus_write_byte(st->client, cmd);

}



static int adm1177_write_alert_thr(struct adm1177_state *st,

				   u32 alert_threshold_ua)

{

	u64 val;

	int ret;



	val = 0xFFULL * alert_threshold_ua * st->r_sense_uohm;

	val = div_u64(val, 105840000U);

	val = div_u64(val, 1000U);

	if (val > 0xFF)

		val = 0xFF;



	ret = i2c_smbus_write_byte_data(st->client, ADM1177_REG_ALERT_TH,

					val);

	if (ret)

		return ret;



	st->alert_threshold_ua = alert_threshold_ua;

	return 0;

}



static int adm1177_read(struct device *dev, enum hwmon_sensor_types type,

			u32 attr, int channel, long *val)

{

	struct adm1177_state *st = dev_get_drvdata(dev);

	u8 data[3];

	long dummy;

	int ret;



	switch (type) {

	case hwmon_curr:

		switch (attr) {

		case hwmon_curr_input:

			ret = adm1177_read_raw(st, 3, data);

			if (ret < 0)

				return ret;

			dummy = (data[1] << 4) | (data[2] & 0xF);

			/*

			 * convert to milliamperes

			 * ((105.84mV / 4096) x raw) / senseResistor(ohm)

			 */

			*val = div_u64((105840000ull * dummy),

				       4096 * st->r_sense_uohm);

			return 0;

		case hwmon_curr_max_alarm:

			*val = st->alert_threshold_ua;

			return 0;

		default:

			return -EOPNOTSUPP;

		}

	case hwmon_in:

		ret = adm1177_read_raw(st, 3, data);

		if (ret < 0)

			return ret;

		dummy = (data[0] << 4) | (data[2] >> 4);

		/*

		 * convert to millivolts based on resistor devision

		 * (V_fullscale / 4096) * raw

		 */

		if (st->vrange_high)

			dummy *= 26350;

		else

			dummy *= 6650;



		*val = DIV_ROUND_CLOSEST(dummy, 4096);

		return 0;

	default:

		return -EOPNOTSUPP;

	}

}



static int adm1177_write(struct device *dev, enum hwmon_sensor_types type,

			 u32 attr, int channel, long val)

{

	struct adm1177_state *st = dev_get_drvdata(dev);



	switch (type) {

	case hwmon_curr:

		switch (attr) {

		case hwmon_curr_max_alarm:

			adm1177_write_alert_thr(st, val);

			return 0;

		default:

			return -EOPNOTSUPP;

		}

	default:

		return -EOPNOTSUPP;

	}

}



static umode_t adm1177_is_visible(const void *data,

				  enum hwmon_sensor_types type,

				  u32 attr, int channel)

{

	const struct adm1177_state *st = data;



	switch (type) {

	case hwmon_in:

		switch (attr) {

		case hwmon_in_input:

			return 0444;

		}

		break;

	case hwmon_curr:

		switch (attr) {

		case hwmon_curr_input:

			if (st->r_sense_uohm)

				return 0444;

			return 0;

		case hwmon_curr_max_alarm:

			if (st->r_sense_uohm)

				return 0644;

			return 0;

		}

		break;

	default:

		break;

	}

	return 0;

}



static const struct hwmon_channel_info *adm1177_info[] = {

	HWMON_CHANNEL_INFO(curr,

			   HWMON_C_INPUT | HWMON_C_MAX_ALARM),

	HWMON_CHANNEL_INFO(in,

			   HWMON_I_INPUT),

	NULL

};



static const struct hwmon_ops adm1177_hwmon_ops = {

	.is_visible = adm1177_is_visible,

	.read = adm1177_read,

	.write = adm1177_write,

};



static const struct hwmon_chip_info adm1177_chip_info = {

	.ops = &adm1177_hwmon_ops,

	.info = adm1177_info,

};



static void adm1177_remove(void *data)

{

	struct adm1177_state *st = data;



	regulator_disable(st->reg);

}



static int adm1177_probe(struct i2c_client *client,

			 const struct i2c_device_id *id)

{

	struct device *dev = &client->dev;

	struct device *hwmon_dev;

	struct adm1177_state *st;

	u32 alert_threshold_ua;

	int ret;



	st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL);

	if (!st)

		return -ENOMEM;



	st->client = client;



	st->reg = devm_regulator_get_optional(&client->dev, "vref");

	if (IS_ERR(st->reg)) {

		if (PTR_ERR(st->reg) == -EPROBE_DEFER)

			return -EPROBE_DEFER;



		st->reg = NULL;

	} else {

		ret = regulator_enable(st->reg);

		if (ret)

			return ret;

		ret = devm_add_action_or_reset(&client->dev, adm1177_remove,

					       st);

		if (ret)

			return ret;

	}



	if (device_property_read_u32(dev, "shunt-resistor-micro-ohms",

				     &st->r_sense_uohm))

		st->r_sense_uohm = 0;

	if (device_property_read_u32(dev, "adi,shutdown-threshold-microamp",

				     &alert_threshold_ua)) {

		if (st->r_sense_uohm)

			/*

			 * set maximum default value from datasheet based on

			 * shunt-resistor

			 */

			alert_threshold_ua = div_u64(105840000000,

						     st->r_sense_uohm);

		else

			alert_threshold_ua = 0;

	}

	st->vrange_high = device_property_read_bool(dev,

						    "adi,vrange-high-enable");

	if (alert_threshold_ua && st->r_sense_uohm)

		adm1177_write_alert_thr(st, alert_threshold_ua);



	ret = adm1177_write_cmd(st, ADM1177_CMD_V_CONT |

				    ADM1177_CMD_I_CONT |

				    (st->vrange_high ? 0 : ADM1177_CMD_VRANGE));

	if (ret)

		return ret;



	hwmon_dev =

		devm_hwmon_device_register_with_info(dev, client->name, st,

						     &adm1177_chip_info, NULL);

	return PTR_ERR_OR_ZERO(hwmon_dev);

}



static const struct i2c_device_id adm1177_id[] = {

	{"adm1177", 0},

	{}

};

MODULE_DEVICE_TABLE(i2c, adm1177_id);



static const struct of_device_id adm1177_dt_ids[] = {

	{ .compatible = "adi,adm1177" },

	{},

};

MODULE_DEVICE_TABLE(of, adm1177_dt_ids);



static struct i2c_driver adm1177_driver = {

	.class = I2C_CLASS_HWMON,

	.driver = {

		.name = "adm1177",

		.of_match_table = adm1177_dt_ids,

	},

	.probe = adm1177_probe,

	.id_table = adm1177_id,

};

module_i2c_driver(adm1177_driver);



MODULE_AUTHOR("Beniamin Bia <beniamin.bia@analog.com>");

MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");

MODULE_DESCRIPTION("Analog Devices ADM1177 ADC driver");

MODULE_LICENSE("GPL v2");