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/*
* Hardware monitoring driver for IR35221
*
* Copyright (C) IBM Corporation 2017.
*
* 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.
*/
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include "pmbus.h"
#define IR35221_MFR_VIN_PEAK 0xc5
#define IR35221_MFR_VOUT_PEAK 0xc6
#define IR35221_MFR_IOUT_PEAK 0xc7
#define IR35221_MFR_TEMP_PEAK 0xc8
#define IR35221_MFR_VIN_VALLEY 0xc9
#define IR35221_MFR_VOUT_VALLEY 0xca
#define IR35221_MFR_IOUT_VALLEY 0xcb
#define IR35221_MFR_TEMP_VALLEY 0xcc
static long ir35221_reg2data(int data, enum pmbus_sensor_classes class)
{
s16 exponent;
s32 mantissa;
long val;
/* We only modify LINEAR11 formats */
exponent = ((s16)data) >> 11;
mantissa = ((s16)((data & 0x7ff) << 5)) >> 5;
val = mantissa * 1000L;
/* scale result to micro-units for power sensors */
if (class == PSC_POWER)
val = val * 1000L;
if (exponent >= 0)
val <<= exponent;
else
val >>= -exponent;
return val;
}
#define MAX_MANTISSA (1023 * 1000)
#define MIN_MANTISSA (511 * 1000)
static u16 ir35221_data2reg(long val, enum pmbus_sensor_classes class)
{
s16 exponent = 0, mantissa;
bool negative = false;
if (val == 0)
return 0;
if (val < 0) {
negative = true;
val = -val;
}
/* Power is in uW. Convert to mW before converting. */
if (class == PSC_POWER)
val = DIV_ROUND_CLOSEST(val, 1000L);
/* Reduce large mantissa until it fits into 10 bit */
while (val >= MAX_MANTISSA && exponent < 15) {
exponent++;
val >>= 1;
}
/* Increase small mantissa to improve precision */
while (val < MIN_MANTISSA && exponent > -15) {
exponent--;
val <<= 1;
}
/* Convert mantissa from milli-units to units */
mantissa = DIV_ROUND_CLOSEST(val, 1000);
/* Ensure that resulting number is within range */
if (mantissa > 0x3ff)
mantissa = 0x3ff;
/* restore sign */
if (negative)
mantissa = -mantissa;
/* Convert to 5 bit exponent, 11 bit mantissa */
return (mantissa & 0x7ff) | ((exponent << 11) & 0xf800);
}
static u16 ir35221_scale_result(s16 data, int shift,
enum pmbus_sensor_classes class)
{
long val;
val = ir35221_reg2data(data, class);
if (shift < 0)
val >>= -shift;
else
val <<= shift;
return ir35221_data2reg(val, class);
}
static int ir35221_read_word_data(struct i2c_client *client, int page, int reg)
{
int ret;
switch (reg) {
case PMBUS_IOUT_OC_FAULT_LIMIT:
case PMBUS_IOUT_OC_WARN_LIMIT:
ret = pmbus_read_word_data(client, page, reg);
if (ret < 0)
break;
ret = ir35221_scale_result(ret, 1, PSC_CURRENT_OUT);
break;
case PMBUS_VIN_OV_FAULT_LIMIT:
case PMBUS_VIN_OV_WARN_LIMIT:
case PMBUS_VIN_UV_WARN_LIMIT:
ret = pmbus_read_word_data(client, page, reg);
ret = ir35221_scale_result(ret, -4, PSC_VOLTAGE_IN);
break;
case PMBUS_IIN_OC_WARN_LIMIT:
ret = pmbus_read_word_data(client, page, reg);
if (ret < 0)
break;
ret = ir35221_scale_result(ret, -1, PSC_CURRENT_IN);
break;
case PMBUS_READ_VIN:
ret = pmbus_read_word_data(client, page, PMBUS_READ_VIN);
if (ret < 0)
break;
ret = ir35221_scale_result(ret, -5, PSC_VOLTAGE_IN);
break;
case PMBUS_READ_IIN:
ret = pmbus_read_word_data(client, page, PMBUS_READ_IIN);
if (ret < 0)
break;
if (page == 0)
ret = ir35221_scale_result(ret, -4, PSC_CURRENT_IN);
else
ret = ir35221_scale_result(ret, -5, PSC_CURRENT_IN);
break;
case PMBUS_READ_POUT:
ret = pmbus_read_word_data(client, page, PMBUS_READ_POUT);
if (ret < 0)
break;
ret = ir35221_scale_result(ret, -1, PSC_POWER);
break;
case PMBUS_READ_PIN:
ret = pmbus_read_word_data(client, page, PMBUS_READ_PIN);
if (ret < 0)
break;
ret = ir35221_scale_result(ret, -1, PSC_POWER);
break;
case PMBUS_READ_IOUT:
ret = pmbus_read_word_data(client, page, PMBUS_READ_IOUT);
if (ret < 0)
break;
if (page == 0)
ret = ir35221_scale_result(ret, -1, PSC_CURRENT_OUT);
else
ret = ir35221_scale_result(ret, -2, PSC_CURRENT_OUT);
break;
case PMBUS_VIRT_READ_VIN_MAX:
ret = pmbus_read_word_data(client, page, IR35221_MFR_VIN_PEAK);
if (ret < 0)
break;
ret = ir35221_scale_result(ret, -5, PSC_VOLTAGE_IN);
break;
case PMBUS_VIRT_READ_VOUT_MAX:
ret = pmbus_read_word_data(client, page, IR35221_MFR_VOUT_PEAK);
break;
case PMBUS_VIRT_READ_IOUT_MAX:
ret = pmbus_read_word_data(client, page, IR35221_MFR_IOUT_PEAK);
if (ret < 0)
break;
if (page == 0)
ret = ir35221_scale_result(ret, -1, PSC_CURRENT_IN);
else
ret = ir35221_scale_result(ret, -2, PSC_CURRENT_IN);
break;
case PMBUS_VIRT_READ_TEMP_MAX:
ret = pmbus_read_word_data(client, page, IR35221_MFR_TEMP_PEAK);
break;
case PMBUS_VIRT_READ_VIN_MIN:
ret = pmbus_read_word_data(client, page,
IR35221_MFR_VIN_VALLEY);
if (ret < 0)
break;
ret = ir35221_scale_result(ret, -5, PSC_VOLTAGE_IN);
break;
case PMBUS_VIRT_READ_VOUT_MIN:
ret = pmbus_read_word_data(client, page,
IR35221_MFR_VOUT_VALLEY);
break;
case PMBUS_VIRT_READ_IOUT_MIN:
ret = pmbus_read_word_data(client, page,
IR35221_MFR_IOUT_VALLEY);
if (ret < 0)
break;
if (page == 0)
ret = ir35221_scale_result(ret, -1, PSC_CURRENT_IN);
else
ret = ir35221_scale_result(ret, -2, PSC_CURRENT_IN);
break;
case PMBUS_VIRT_READ_TEMP_MIN:
ret = pmbus_read_word_data(client, page,
IR35221_MFR_TEMP_VALLEY);
break;
default:
ret = -ENODATA;
break;
}
return ret;
}
static int ir35221_write_word_data(struct i2c_client *client, int page, int reg,
u16 word)
{
int ret;
u16 val;
switch (reg) {
case PMBUS_IOUT_OC_FAULT_LIMIT:
case PMBUS_IOUT_OC_WARN_LIMIT:
val = ir35221_scale_result(word, -1, PSC_CURRENT_OUT);
ret = pmbus_write_word_data(client, page, reg, val);
break;
case PMBUS_VIN_OV_FAULT_LIMIT:
case PMBUS_VIN_OV_WARN_LIMIT:
case PMBUS_VIN_UV_WARN_LIMIT:
val = ir35221_scale_result(word, 4, PSC_VOLTAGE_IN);
ret = pmbus_write_word_data(client, page, reg, val);
break;
case PMBUS_IIN_OC_WARN_LIMIT:
val = ir35221_scale_result(word, 1, PSC_CURRENT_IN);
ret = pmbus_write_word_data(client, page, reg, val);
break;
default:
ret = -ENODATA;
break;
}
return ret;
}
static int ir35221_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct pmbus_driver_info *info;
u8 buf[I2C_SMBUS_BLOCK_MAX];
int ret;
if (!i2c_check_functionality(client->adapter,
I2C_FUNC_SMBUS_READ_BYTE_DATA
| I2C_FUNC_SMBUS_READ_WORD_DATA
| I2C_FUNC_SMBUS_READ_BLOCK_DATA))
return -ENODEV;
ret = i2c_smbus_read_block_data(client, PMBUS_MFR_ID, buf);
if (ret < 0) {
dev_err(&client->dev, "Failed to read PMBUS_MFR_ID\n");
return ret;
}
if (ret != 2 || strncmp(buf, "RI", strlen("RI"))) {
dev_err(&client->dev, "MFR_ID unrecognised\n");
return -ENODEV;
}
ret = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, buf);
if (ret < 0) {
dev_err(&client->dev, "Failed to read PMBUS_MFR_MODEL\n");
return ret;
}
if (ret != 2 || !(buf[0] == 0x6c && buf[1] == 0x00)) {
dev_err(&client->dev, "MFR_MODEL unrecognised\n");
return -ENODEV;
}
info = devm_kzalloc(&client->dev, sizeof(struct pmbus_driver_info),
GFP_KERNEL);
if (!info)
return -ENOMEM;
info->write_word_data = ir35221_write_word_data;
info->read_word_data = ir35221_read_word_data;
info->pages = 2;
info->format[PSC_VOLTAGE_IN] = linear;
info->format[PSC_VOLTAGE_OUT] = linear;
info->format[PSC_CURRENT_IN] = linear;
info->format[PSC_CURRENT_OUT] = linear;
info->format[PSC_POWER] = linear;
info->format[PSC_TEMPERATURE] = linear;
info->func[0] = PMBUS_HAVE_VIN
| PMBUS_HAVE_VOUT | PMBUS_HAVE_IIN
| PMBUS_HAVE_IOUT | PMBUS_HAVE_PIN
| PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP
| PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT
| PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP;
info->func[1] = info->func[0];
return pmbus_do_probe(client, id, info);
}
static const struct i2c_device_id ir35221_id[] = {
{"ir35221", 0},
{}
};
MODULE_DEVICE_TABLE(i2c, ir35221_id);
static struct i2c_driver ir35221_driver = {
.driver = {
.name = "ir35221",
},
.probe = ir35221_probe,
.remove = pmbus_do_remove,
.id_table = ir35221_id,
};
module_i2c_driver(ir35221_driver);
MODULE_AUTHOR("Samuel Mendoza-Jonas <sam@mendozajonas.com");
MODULE_DESCRIPTION("PMBus driver for IR35221");
MODULE_LICENSE("GPL");
|
