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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Hardware monitoring driver for LTC3815
*
* Copyright (c) 2015 Linear Technology
* Copyright (c) 2015 Guenter Roeck
*/
#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, 0xff, 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 phase, int reg)
{
int ret;
switch (reg) {
case PMBUS_VIRT_READ_VIN_MAX:
ret = pmbus_read_word_data(client, page, phase,
LTC3815_MFR_VIN_PEAK);
break;
case PMBUS_VIRT_READ_VOUT_MAX:
ret = pmbus_read_word_data(client, page, phase,
LTC3815_MFR_VOUT_PEAK);
break;
case PMBUS_VIRT_READ_TEMP_MAX:
ret = pmbus_read_word_data(client, page, phase,
LTC3815_MFR_TEMP_PEAK);
break;
case PMBUS_VIRT_READ_IOUT_MAX:
ret = pmbus_read_word_data(client, page, phase,
LTC3815_MFR_IOUT_PEAK);
break;
case PMBUS_VIRT_READ_IIN_MAX:
ret = pmbus_read_word_data(client, page, phase,
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)
{
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, <c3815_info);
}
static struct i2c_driver ltc3815_driver = {
.driver = {
.name = "ltc3815",
},
.probe_new = ltc3815_probe,
.id_table = ltc3815_id,
};
module_i2c_driver(ltc3815_driver);
MODULE_AUTHOR("Guenter Roeck");
MODULE_DESCRIPTION("PMBus driver for LTC3815");
MODULE_LICENSE("GPL");
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