Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 8d28cd1b authored by Guenter Roeck's avatar Guenter Roeck
Browse files

hwmon: (pmbus) Add client driver for LTC3815 



LTC3815 is a Monolithic Synchronous DC/DC Step-Down Converter.

Cc: Michael Jones <mike@proclivis.com>
Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent 2ff44072

Documentation/hwmon/ltc3815

0 → 100644
+61 −0
Original line number Diff line number Diff line 
Kernel driver ltc3815

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



Supported chips:

  * Linear Technology LTC3815

    Prefix: 'ltc3815'

    Addresses scanned: -

    Datasheet: http://www.linear.com/product/ltc3815



Author: Guenter Roeck <linux@roeck-us.net>





Description

-----------



LTC3815 is a Monolithic Synchronous DC/DC Step-Down Converter.





Usage Notes

-----------



This driver does not probe for PMBus devices. You will have to instantiate

devices explicitly.



Example: the following commands will load the driver for an LTC3815

at address 0x20 on I2C bus #1:



# modprobe ltc3815

# echo ltc3815 0x20 > /sys/bus/i2c/devices/i2c-1/new_device





Sysfs attributes

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



in1_label		"vin"

in1_input		Measured input voltage.

in1_alarm		Input voltage alarm.

in1_highest		Highest input voltage.

in1_reset_history	Reset input voltage history.



in2_label		"vout1".

in2_input		Measured output voltage.

in2_alarm		Output voltage alarm.

in2_highest		Highest output voltage.

in2_reset_history	Reset output voltage history.



temp1_input		Measured chip temperature.

temp1_alarm		Temperature alarm.

temp1_highest		Highest measured temperature.

temp1_reset_history	Reset temperature history.



curr1_label		"iin".

curr1_input		Measured input current.

curr1_highest		Highest input current.

curr1_reset_history	Reset input current history.



curr2_label		"iout1".

curr2_input		Measured output current.

curr2_alarm		Output current alarm.

curr2_highest		Highest output current.

curr2_reset_history	Reset output current history.

drivers/hwmon/pmbus/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -65,6 +65,16 @@ config SENSORS_LTC2978_REGULATOR 
	  If you say yes here you get regulator support for Linear

	  Technology LTC2974, LTC2977, LTC2978, LTC3880, LTC3883, and LTM4676.



config SENSORS_LTC3815

	tristate "Linear Technologies LTC3815"

	default n

	help

	  If you say yes here you get hardware monitoring support for Linear

	  Technology LTC3815.



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

	  be called ltc3815.



config SENSORS_MAX16064

	tristate "Maxim MAX16064"

	default n

drivers/hwmon/pmbus/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ obj-$(CONFIG_SENSORS_PMBUS) += pmbus.o 
obj-$(CONFIG_SENSORS_ADM1275)	+= adm1275.o

obj-$(CONFIG_SENSORS_LM25066)	+= lm25066.o

obj-$(CONFIG_SENSORS_LTC2978)	+= ltc2978.o

obj-$(CONFIG_SENSORS_LTC3815)	+= ltc3815.o

obj-$(CONFIG_SENSORS_MAX16064)	+= max16064.o

obj-$(CONFIG_SENSORS_MAX20751)	+= max20751.o

obj-$(CONFIG_SENSORS_MAX34440)	+= max34440.o

drivers/hwmon/pmbus/ltc3815.c

0 → 100644
+215 −0
Original line number Diff line number Diff line 
/*

 * Hardware monitoring driver for LTC3815

 *

 * Copyright (c) 2015 Linear Technology

 * Copyright (c) 2015 Guenter Roeck

 *

 * 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/i2c.h>

#include <linux/init.h>

#include <linux/jiffies.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include "pmbus.h"



#define LTC3815_MFR_IOUT_PEAK	0xd7

#define LTC3815_MFR_VOUT_PEAK	0xdd

#define LTC3815_MFR_VIN_PEAK	0xde

#define LTC3815_MFR_TEMP_PEAK	0xdf

#define LTC3815_MFR_IIN_PEAK	0xe1

#define LTC3815_MFR_SPECIAL_ID	0xe7



#define LTC3815_ID		0x8000

#define LTC3815_ID_MASK		0xff00



static int ltc3815_read_byte_data(struct i2c_client *client, int page, int reg)

{

	int ret;



	switch (reg) {

	case PMBUS_VOUT_MODE:

		/*

		 * The chip returns 0x3e, suggesting VID mode with manufacturer

		 * specific VID codes. Since the output voltage is reported

		 * with a LSB of 0.5mV, override and report direct mode with

		 * appropriate coefficients.

		 */

		ret = 0x40;

		break;

	default:

		ret = -ENODATA;

		break;

	}

	return ret;

}



static int ltc3815_write_byte(struct i2c_client *client, int page, u8 reg)

{

	int ret;



	switch (reg) {

	case PMBUS_CLEAR_FAULTS:

		/*

		 * LTC3815 does not support the CLEAR_FAULTS command.

		 * Emulate it by clearing the status register.

		 */

		ret = pmbus_read_word_data(client, 0, PMBUS_STATUS_WORD);

		if (ret > 0) {

			pmbus_write_word_data(client, 0, PMBUS_STATUS_WORD,

					      ret);

			ret = 0;

		}

		break;

	default:

		ret = -ENODATA;

		break;

	}

	return ret;

}



static int ltc3815_read_word_data(struct i2c_client *client, int page, int reg)

{

	int ret;



	switch (reg) {

	case PMBUS_VIRT_READ_VIN_MAX:

		ret = pmbus_read_word_data(client, page, LTC3815_MFR_VIN_PEAK);

		break;

	case PMBUS_VIRT_READ_VOUT_MAX:

		ret = pmbus_read_word_data(client, page, LTC3815_MFR_VOUT_PEAK);

		break;

	case PMBUS_VIRT_READ_TEMP_MAX:

		ret = pmbus_read_word_data(client, page, LTC3815_MFR_TEMP_PEAK);

		break;

	case PMBUS_VIRT_READ_IOUT_MAX:

		ret = pmbus_read_word_data(client, page, LTC3815_MFR_IOUT_PEAK);

		break;

	case PMBUS_VIRT_READ_IIN_MAX:

		ret = pmbus_read_word_data(client, page, LTC3815_MFR_IIN_PEAK);

		break;

	case PMBUS_VIRT_RESET_VOUT_HISTORY:

	case PMBUS_VIRT_RESET_VIN_HISTORY:

	case PMBUS_VIRT_RESET_TEMP_HISTORY:

	case PMBUS_VIRT_RESET_IOUT_HISTORY:

	case PMBUS_VIRT_RESET_IIN_HISTORY:

		ret = 0;

		break;

	default:

		ret = -ENODATA;

		break;

	}

	return ret;

}



static int ltc3815_write_word_data(struct i2c_client *client, int page,

				   int reg, u16 word)

{

	int ret;



	switch (reg) {

	case PMBUS_VIRT_RESET_IIN_HISTORY:

		ret = pmbus_write_word_data(client, page,

					    LTC3815_MFR_IIN_PEAK, 0);

		break;

	case PMBUS_VIRT_RESET_IOUT_HISTORY:

		ret = pmbus_write_word_data(client, page,

					    LTC3815_MFR_IOUT_PEAK, 0);

		break;

	case PMBUS_VIRT_RESET_VOUT_HISTORY:

		ret = pmbus_write_word_data(client, page,

					    LTC3815_MFR_VOUT_PEAK, 0);

		break;

	case PMBUS_VIRT_RESET_VIN_HISTORY:

		ret = pmbus_write_word_data(client, page,

					    LTC3815_MFR_VIN_PEAK, 0);

		break;

	case PMBUS_VIRT_RESET_TEMP_HISTORY:

		ret = pmbus_write_word_data(client, page,

					    LTC3815_MFR_TEMP_PEAK, 0);

		break;

	default:

		ret = -ENODATA;

		break;

	}

	return ret;

}



static const struct i2c_device_id ltc3815_id[] = {

	{"ltc3815", 0},

	{ }

};

MODULE_DEVICE_TABLE(i2c, ltc3815_id);



static struct pmbus_driver_info ltc3815_info = {

	.pages = 1,

	.format[PSC_VOLTAGE_IN] = direct,

	.format[PSC_VOLTAGE_OUT] = direct,

	.format[PSC_CURRENT_IN] = direct,

	.format[PSC_CURRENT_OUT] = direct,

	.format[PSC_TEMPERATURE] = direct,

	.m[PSC_VOLTAGE_IN] = 250,

	.b[PSC_VOLTAGE_IN] = 0,

	.R[PSC_VOLTAGE_IN] = 0,

	.m[PSC_VOLTAGE_OUT] = 2,

	.b[PSC_VOLTAGE_OUT] = 0,

	.R[PSC_VOLTAGE_OUT] = 3,

	.m[PSC_CURRENT_IN] = 1,

	.b[PSC_CURRENT_IN] = 0,

	.R[PSC_CURRENT_IN] = 2,

	.m[PSC_CURRENT_OUT] = 1,

	.b[PSC_CURRENT_OUT] = 0,

	.R[PSC_CURRENT_OUT] = 2,

	.m[PSC_TEMPERATURE] = 1,

	.b[PSC_TEMPERATURE] = 0,

	.R[PSC_TEMPERATURE] = 0,

	.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN | PMBUS_HAVE_VOUT |

		PMBUS_HAVE_IOUT | PMBUS_HAVE_TEMP,

	.read_byte_data = ltc3815_read_byte_data,

	.read_word_data = ltc3815_read_word_data,

	.write_byte = ltc3815_write_byte,

	.write_word_data = ltc3815_write_word_data,

};



static int ltc3815_probe(struct i2c_client *client,

			 const struct i2c_device_id *id)

{

	int chip_id;



	if (!i2c_check_functionality(client->adapter,

				     I2C_FUNC_SMBUS_READ_WORD_DATA))

		return -ENODEV;



	chip_id = i2c_smbus_read_word_data(client, LTC3815_MFR_SPECIAL_ID);

	if (chip_id < 0)

		return chip_id;

	if ((chip_id & LTC3815_ID_MASK) != LTC3815_ID)

		return -ENODEV;



	return pmbus_do_probe(client, id, &ltc3815_info);

}



static struct i2c_driver ltc3815_driver = {

	.driver = {

		   .name = "ltc3815",

		   },

	.probe = ltc3815_probe,

	.remove = pmbus_do_remove,

	.id_table = ltc3815_id,

};



module_i2c_driver(ltc3815_driver);



MODULE_AUTHOR("Guenter Roeck");

MODULE_DESCRIPTION("PMBus driver for LTC3815");

MODULE_LICENSE("GPL");