// SPDX-License-Identifier: GPL-2.0-only
/*
* Measurements Specialties driver common i2c functions
*
* Copyright (c) 2015 Measurement-Specialties
*/
#include <linux/module.h>
#include <linux/iio/iio.h>
#include <linux/device.h>
#include <linux/delay.h>
#include "ms_sensors_i2c.h"
/* Conversion times in us */
static const u16 ms_sensors_ht_t_conversion_time[] = { 50000, 25000,
13000, 7000 };
static const u16 ms_sensors_ht_h_conversion_time[] = { 16000, 5000,
3000, 8000 };
static const u16 ms_sensors_tp_conversion_time[] = { 500, 1100, 2100,
4100, 8220, 16440 };
#define MS_SENSORS_SERIAL_READ_MSB 0xFA0F
#define MS_SENSORS_SERIAL_READ_LSB 0xFCC9
#define MS_SENSORS_CONFIG_REG_WRITE 0xE6
#define MS_SENSORS_CONFIG_REG_READ 0xE7
#define MS_SENSORS_HT_T_CONVERSION_START 0xF3
#define MS_SENSORS_HT_H_CONVERSION_START 0xF5
#define MS_SENSORS_TP_PROM_READ 0xA0
#define MS_SENSORS_TP_T_CONVERSION_START 0x50
#define MS_SENSORS_TP_P_CONVERSION_START 0x40
#define MS_SENSORS_TP_ADC_READ 0x00
#define MS_SENSORS_NO_READ_CMD 0xFF
/**
* ms_sensors_reset() - Reset function
* @cli: pointer to device client
* @cmd: reset cmd. Depends on device in use
* @delay: usleep minimal delay after reset command is issued
*
* Generic I2C reset function for Measurement Specialties devices.
*
* Return: 0 on success, negative errno otherwise.
*/
int ms_sensors_reset(void *cli, u8 cmd, unsigned int delay)
{
int ret;
struct i2c_client *client = cli;
ret = i2c_smbus_write_byte(client, cmd);
if (ret) {
dev_err(&client->dev, "Failed to reset device\n");
return ret;
}
usleep_range(delay, delay + 1000);
return 0;
}
EXPORT_SYMBOL_NS(ms_sensors_reset, IIO_MEAS_SPEC_SENSORS);
/**
* ms_sensors_read_prom_word() - PROM word read function
* @cli: pointer to device client
* @cmd: PROM read cmd. Depends on device and prom id
* @word: pointer to word destination value
*
* Generic i2c prom word read function for Measurement Specialties devices.
*
* Return: 0 on success, negative errno otherwise.
*/
int ms_sensors_read_prom_word(void *cli, int cmd, u16 *word)
{
int ret;
struct i2c_client *client = cli;
ret = i2c_smbus_read_word_swapped(client, cmd);
if (ret < 0) {
dev_err(&client->dev, "Failed to read prom word\n");
return ret;
}
*word = ret;
return 0;
}
EXPORT_SYMBOL_NS(ms_sensors_read_prom_word, IIO_MEAS_SPEC_SENSORS);
/**
* ms_sensors_convert_and_read() - ADC conversion & read function
* @cli: pointer to device client
* @conv: ADC conversion command. Depends on device in use
* @rd: ADC read command. Depends on device in use
* @delay: usleep minimal delay after conversion command is issued
* @adc: pointer to ADC destination value
*
* Generic ADC conversion & read function for Measurement Specialties
* devices.
* The function will issue conversion command, sleep appopriate delay, and
* issue command to read ADC.
*
* Return: 0 on success, negative errno otherwise.
*/
int ms_sensors_convert_and_read(void *cli, u8 conv, u8 rd,
unsigned int delay, u32 *adc)
{
int ret;
__be32 buf = 0;
struct i2c_client *client = cli;
/* Trigger conversion */
ret = i2c_smbus_write_byte(client, conv);
if (ret)
goto err;
usleep_range(delay, delay + 1000);
/* Retrieve ADC value */
if (rd != MS_SENSORS_NO_READ_CMD)
ret = i2c_smbus_read_i2c_block_data(client, rd, 3, (u8 *)&buf);
else
ret = i2c_master_recv(client, (u8 *)&buf, 3);
if (ret < 0)
goto err;
dev_dbg(&client->dev, "ADC raw value : %x\n", be32_to_cpu(buf) >> 8);
*adc = be32_to_cpu(buf) >> 8;
return 0;
err:
dev_err(&client->dev, "Unable to make sensor adc conversion\n");
return ret;
}
EXPORT_SYMBOL_NS(ms_sensors_convert_and_read, IIO_MEAS_SPEC_SENSORS);
/**
* ms_sensors_crc_valid() - CRC check function
* @value: input and CRC compare value
*
* Cyclic Redundancy Check function used in TSYS02D, HTU21, MS8607.
* This function performs a x^8 + x^5 + x^4 + 1 polynomial CRC.
* The argument contains CRC value in LSB byte while the bytes 1 and 2
* are used for CRC computation.
*
* Return: 1 if CRC is valid, 0 otherwise.
*/
static bool ms_sensors_crc_valid(u32 value)
{
u32 polynom = 0x988000; /* x^8 + x^5 + x^4 + 1 */
u32 msb = 0x800000;
u32 mask = 0xFF8000;
u32 result = value & 0xFFFF00;
u8 crc = value & 0xFF;
while (msb != 0x80) {
if (result & msb)
result = ((result ^ polynom) & mask)
| (result & ~mask);
msb >>= 1;
mask >>= 1;
polynom >>= 1;
}
return result == crc;
}
/**
* ms_sensors_read_serial() - Serial number read function
* @client: pointer to i2c client
* @sn: pointer to 64-bits destination value
*
* Generic i2c serial number read function for Measurement Specialties devices.
* This function is used for TSYS02d, HTU21, MS8607 chipset.
* Refer to datasheet:
* http://www.meas-spec.com/downloads/HTU2X_Serial_Number_Reading.pdf
*
* Sensor raw MSB serial number format is the following :
* [ SNB3, CRC, SNB2, CRC, SNB1, CRC, SNB0, CRC]
* Sensor raw LSB serial number format is the following :
* [ X, X, SNC1, SNC0, CRC, SNA1, SNA0, CRC]
* The resulting serial number is following :
* [ SNA1, SNA0, SNB3, SNB2, SNB1, SNB0, SNC1, SNC0]
*
* Return: 0 on success, negative errno otherwise.
*/
int ms_sensors_read_serial(struct i2c_client *client, u64 *sn)
{
u8 i;
__be64 rcv_buf = 0;
u64 rcv_val;
__be16 send_buf;
int ret;
struct i2c_msg msg[2] = {
{
.addr = client->addr,
.flags = client->flags,
.len = 2,
.buf = (__u8 *)&send_buf,
},
{
.addr = client->addr,
.flags = client->flags | I2C_M_RD,
.buf = (__u8 *)&rcv_buf,
},
};
/* Read MSB part of serial number */
send_buf = cpu_to_be16(MS_SENSORS_SERIAL_READ_MSB);
msg[1].len = 8;
ret = i2c_transfer(client->adapter, msg, 2);
if (ret < 0) {
dev_err(&client->dev, "Unable to read device serial number");
return ret;
}
rcv_val = be64_to_cpu(rcv_buf);
dev_dbg(&client->dev, "Serial MSB raw : %llx\n", rcv_val);
for (i = 0; i < 64; i += 16) {
if (!ms_sensors_crc_valid((rcv_val >> i) & 0xFFFF))
return -ENODEV;
}
*sn = (((rcv_val >> 32) & 0xFF000000) |
((rcv_val >> 24) & 0x00FF0000) |
((rcv_val >> 16) & 0x0000FF00) |
((rcv_val >> 8) & 0x000000FF)) << 16;
/* Read LSB part of serial number */
send_buf = cpu_to_be16(MS_SENSORS_SERIAL_READ_LSB);
msg[1].len = 6;
rcv_buf = 0;
ret = i2c_transfer(client->adapter, msg, 2);
if (ret < 0) {
dev_err(&client->dev, "Unable to read device serial number");
return ret;
}
rcv_val = be64_to_cpu(rcv_buf) >> 16;
dev_dbg(&client->dev, "Serial MSB raw : %llx\n", rcv_val);
for (i = 0; i < 48; i += 24) {
if (!ms_sensors_crc_valid((rcv_val >> i) & 0xFFFFFF))
return -ENODEV;
}
*sn |= (rcv_val & 0xFFFF00) << 40 | (rcv_val >> 32);
return 0;
}
EXPORT_SYMBOL_NS(ms_sensors_read_serial, IIO_MEAS_SPEC_SENSORS);
static int ms_sensors_read_config_reg(struct i2c_client *client,
u8 *config_reg)
{
int ret;
ret = i2c_smbus_write_byte(client, MS_SENSORS_CONFIG_REG_READ);
if (ret) {
dev_err(&client->dev, "Unable to read config register");
return ret;
}
ret = i2c_master_recv(client, config_reg, 1);
if (ret < 0) {
dev_err(&client->dev, "Unable to read config register");
return ret;
}
dev_dbg(&client->dev, "Config register :%x\n", *config_reg);
return 0;
}
/**
* ms_sensors_write_resolution() - Set resolution function
* @dev_data: pointer to temperature/humidity device data
* @i: resolution index to set
*
* This function will program the appropriate resolution based on the index
* provided when user space will set samp_freq channel.
* This function is used for TSYS02D, HTU21 and MS8607 chipsets.
*
* Return: 0 on success, negative errno otherwise.
*/
ssize_t ms_sensors_write_resolution(struct ms_ht_dev *dev_data,
u8 i)
{
u8 config_reg;
int ret;
ret = ms_sensors_read_config_reg(dev_data->client, &config_reg);
if (ret)
return ret;
config_reg &= 0x7E;
config_reg |= ((i & 1) << 7) + ((i & 2) >> 1);
return i2c_smbus_write_byte_data(dev_data->client,
MS_SENSORS_CONFIG_REG_WRITE,
config_reg);
}
EXPORT_SYMBOL_NS(ms_sensors_write_resolution, IIO_MEAS_SPEC_SENSORS);
/**
* ms_sensors_show_battery_low() - Show device battery low indicator
* @dev_data: pointer to temperature/humidity device data
* @buf: pointer to char buffer to write result
*
* This function will read battery indicator value in the device and
* return 1 if the device voltage is below 2.25V.
* This function is used for TSYS02D, HTU21 and MS8607 chipsets.
*
* Return: length of sprintf on success, negative errno otherwise.
*/
ssize_t ms_sensors_show_battery_low(struct ms_ht_dev *dev_data,
char *buf)
{
int ret;
u8 config_reg;
mutex_lock(&dev_data->lock);
ret = ms_sensors_read_config_reg(dev_data->client, &config_reg);
mutex_unlock(&dev_data->lock);
if (ret)
return ret;
return sysfs_emit(buf, "%d\n", (config_reg & 0x40) >> 6);
}
EXPORT_SYMBOL_NS(ms_sensors_show_battery_low, IIO_MEAS_SPEC_SENSORS);
/**
* ms_sensors_show_heater() - Show device heater
* @dev_data: pointer to temperature/humidity device data
* @buf: pointer to char buffer to write result
*
* This function will read heater enable value in the device and
* return 1 if the heater is enabled.
* This function is used for HTU21 and MS8607 chipsets.
*
* Return: length of sprintf on success, negative errno otherwise.
*/
ssize_t ms_sensors_show_heater(struct ms_ht_dev *dev_data,
char *buf)
{
u8 config_reg;
int ret;
mutex_lock(&dev_data->lock);
ret = ms_sensors_read_config_reg(dev_data->client, &config_reg);
mutex_unlock(&dev_data->lock);
if (ret)
return ret;
return sysfs_emit(buf, "%d\n", (config_reg & 0x4) >> 2);
}
EXPORT_SYMBOL_NS(ms_sensors_show_heater, IIO_MEAS_SPEC_SENSORS);
/**
* ms_sensors_write_heater() - Write device heater
* @dev_data: pointer to temperature/humidity device data
* @buf: pointer to char buffer from user space
* @len: length of buf
*
* This function will write 1 or 0 value in the device
* to enable or disable heater.
* This function is used for HTU21 and MS8607 chipsets.
*
* Return: length of buffer, negative errno otherwise.
*/
ssize_t ms_sensors_write_heater(struct ms_ht_dev *dev_data,
const char *buf, size_t len)
{
u8 val, config_reg;
int ret;
ret = kstrtou8(buf, 10, &val);
if (ret)
return ret;
if (val > 1)
return -EINVAL;
mutex_lock(&dev_data->lock);
ret = ms_sensors_read_config_reg(dev_data->client, &config_reg);
if (ret) {
mutex_unlock(&dev_data->lock);
return ret;
}
config_reg &= 0xFB;
config_reg |= val << 2;
ret = i2c_smbus_write_byte_data(dev_data->client,
MS_SENSORS_CONFIG_REG_WRITE,
config_reg);
mutex_unlock(&dev_data->lock);
if (ret) {
dev_err(&dev_data->client->dev, "Unable to write config register\n");
return ret;
}
return len;
}
EXPORT_SYMBOL_NS(ms_sensors_write_heater, IIO_MEAS_SPEC_SENSORS);
/**
* ms_sensors_ht_read_temperature() - Read temperature
* @dev_data: pointer to temperature/humidity device data
* @temperature:pointer to temperature destination value
*
* This function will get temperature ADC value from the device,
* check the CRC and compute the temperature value.
* This function is used for TSYS02D, HTU21 and MS8607 chipsets.
*
* Return: 0 on success, negative errno otherwise.
*/
int ms_sensors_ht_read_temperature(struct ms_ht_dev *dev_data,
s32 *temperature)
{
int ret;
u32 adc;
u16 delay;
mutex_lock(&dev_data->lock);
delay = ms_sensors_ht_t_conversion_time[dev_data->res_index];
ret = ms_sensors_convert_and_read(dev_data->client,
MS_SENSORS_HT_T_CONVERSION_START,
MS_SENSORS_NO_READ_CMD,
delay, &adc);
mutex_unlock(&dev_data->lock);
if (ret)
return ret;
if (!ms_sensors_crc_valid(adc)) {
dev_err(&dev_data->client->dev,
"Temperature read crc check error\n");
return -ENODEV;
}
/* Temperature algorithm */
*temperature = (((s64)(adc >> 8) * 175720) >> 16) - 46850;
return 0;
}
EXPORT_SYMBOL_NS(ms_sensors_ht_read_temperature, IIO_MEAS_SPEC_SENSORS);
/**
* ms_sensors_ht_read_humidity() - Read humidity
* @dev_data: pointer to temperature/humidity device data
* @humidity: pointer to humidity destination value
*
* This function will get humidity ADC value from the device,
* check the CRC and compute the temperature value.
* This function is used for HTU21 and MS8607 chipsets.
*
* Return: 0 on success, negative errno otherwise.
*/
int ms_sensors_ht_read_humidity(struct ms_ht_dev *dev_data,
u32 *humidity)
{
int ret;
u32 adc;
u16 delay;
mutex_lock(&dev_data->lock);
delay = ms_sensors_ht_h_conversion_time[dev_data->res_index];
ret = ms_sensors_convert_and_read(dev_data->client,
MS_SENSORS_HT_H_CONVERSION_START,
MS_SENSORS_NO_READ_CMD,
delay, &adc);
mutex_unlock(&dev_data->lock);
if (ret)
return ret;
if (!ms_sensors_crc_valid(adc)) {
dev_err(&dev_data->client->dev,
"Humidity read crc check error\n");
return -ENODEV;
}
/* Humidity algorithm */
*humidity = (((s32)(adc >> 8) * 12500) >> 16) * 10 - 6000;
if (*humidity >= 100000)
*humidity = 100000;
return 0;
}
EXPORT_SYMBOL_NS(ms_sensors_ht_read_humidity, IIO_MEAS_SPEC_SENSORS);
/**
* ms_sensors_tp_crc4() - Calculate PROM CRC for
* Temperature and pressure devices.
* This function is only used when reading PROM coefficients
*
* @prom: pointer to PROM coefficients array
*
* Return: CRC.
*/
static u8 ms_sensors_tp_crc4(u16 *prom)
{
unsigned int cnt, n_bit;
u16 n_rem = 0x0000;
for (cnt = 0; cnt < MS_SENSORS_TP_PROM_WORDS_NB * 2; cnt++) {
if (cnt % 2 == 1)
n_rem ^= prom[cnt >> 1] & 0x00FF;
else
n_rem ^= prom[cnt >> 1] >> 8;
for (n_bit = 8; n_bit > 0; n_bit--) {
if (n_rem & 0x8000)
n_rem = (n_rem << 1) ^ 0x3000;
else
n_rem <<= 1;
}
}
return n_rem >> 12;
}
/**
* ms_sensors_tp_crc_valid_112() - CRC check function for
* Temperature and pressure devices for 112bit PROM.
* This function is only used when reading PROM coefficients
*
* @prom: pointer to PROM coefficients array
*
* Return: True if CRC is ok.
*/
static bool ms_sensors_tp_crc_valid_112(u16 *prom)
{
u16 w0 = prom[0], crc_read = (w0 & 0xF000) >> 12;
u8 crc;
prom[0] &= 0x0FFF; /* Clear the CRC computation part */
prom[MS_SENSORS_TP_PROM_WORDS_NB - 1] = 0;
crc = ms_sensors_tp_crc4(prom);
prom[0] = w0;
return crc == crc_read;
}
/**
* ms_sensors_tp_crc_valid_128() - CRC check function for
* Temperature and pressure devices for 128bit PROM.
* This function is only used when reading PROM coefficients
*
* @prom: pointer to PROM coefficients array
*
* Return: True if CRC is ok.
*/
static bool ms_sensors_tp_crc_valid_128(u16 *prom)
{
u16 w7 = prom[7], crc_read = w7 & 0x000F;
u8 crc;
prom[7] &= 0xFF00; /* Clear the CRC and LSB part */
crc = ms_sensors_tp_crc4(prom);
prom[7] = w7;
return crc == crc_read;
}
/**
* ms_sensors_tp_read_prom() - prom coeff read function
* @dev_data: pointer to temperature/pressure device data
*
* This function will read prom coefficients and check CRC.
* This function is used for MS5637 and MS8607 chipsets.
*
* Return: 0 on success, negative errno otherwise.
*/
int ms_sensors_tp_read_prom(struct ms_tp_dev *dev_data)
{
int i, ret;
bool valid;
for (i = 0; i < dev_data->hw->prom_len; i++) {
ret = ms_sensors_read_prom_word(
dev_data->client,
MS_SENSORS_TP_PROM_READ + (i << 1),
&dev_data->prom[i]);
if (ret)
return ret;
}
if (dev_data->hw->prom_len == 8)
valid = ms_sensors_tp_crc_valid_128(dev_data->prom);
else
valid = ms_sensors_tp_crc_valid_112(dev_data->prom);
if (!valid) {
dev_err(&dev_data->client->dev,
"Calibration coefficients crc check error\n");
return -ENODEV;
}
return 0;
}
EXPORT_SYMBOL_NS(ms_sensors_tp_read_prom, IIO_MEAS_SPEC_SENSORS);
/**
* ms_sensors_read_temp_and_pressure() - read temp and pressure
* @dev_data: pointer to temperature/pressure device data
* @temperature:pointer to temperature destination value
* @pressure: pointer to pressure destination value
*
* This function will read ADC and compute pressure and temperature value.
* This function is used for MS5637 and MS8607 chipsets.
*
* Return: 0 on success, negative errno otherwise.
*/
int ms_sensors_read_temp_and_pressure(struct ms_tp_dev *dev_data,
int *temperature,
unsigned int *pressure)
{
int ret;
u32 t_adc, p_adc;
s32 dt, temp;
s64 off, sens, t2, off2, sens2;
u16 *prom = dev_data->prom, delay;
mutex_lock(&dev_data->lock);
delay = ms_sensors_tp_conversion_time[dev_data->res_index];
ret = ms_sensors_convert_and_read(
dev_data->client,
MS_SENSORS_TP_T_CONVERSION_START +
dev_data->res_index * 2,
MS_SENSORS_TP_ADC_READ,
delay, &t_adc);
if (ret) {
mutex_unlock(&dev_data->lock);
return ret;
}
ret = ms_sensors_convert_and_read(
dev_data->client,
MS_SENSORS_TP_P_CONVERSION_START +
dev_data->res_index * 2,
MS_SENSORS_TP_ADC_READ,
delay, &p_adc);
mutex_unlock(&dev_data->lock);
if (ret)
return ret;
dt = (s32)t_adc - (prom[5] << 8);
/* Actual temperature = 2000 + dT * TEMPSENS */
temp = 2000 + (((s64)dt * prom[6]) >> 23);
/* Second order temperature compensation */
if (temp < 2000) {
s64 tmp = (s64)temp - 2000;
t2 = (3 * ((s64)dt * (s64)dt)) >> 33;
off2 = (61 * tmp * tmp) >> 4;
sens2 = (29 * tmp * tmp) >> 4;
if (temp < -1500) {
s64 tmp = (s64)temp + 1500;
off2 += 17 * tmp * tmp;
sens2 += 9 * tmp * tmp;
}
} else {
t2 = (5 * ((s64)dt * (s64)dt)) >> 38;
off2 = 0;
sens2 = 0;
}
/* OFF = OFF_T1 + TCO * dT */
off = (((s64)prom[2]) << 17) + ((((s64)prom[4]) * (s64)dt) >> 6);
off -= off2;
/* Sensitivity at actual temperature = SENS_T1 + TCS * dT */
sens = (((s64)prom[1]) << 16) + (((s64)prom[3] * dt) >> 7);
sens -= sens2;
/* Temperature compensated pressure = D1 * SENS - OFF */
*temperature = (temp - t2) * 10;
*pressure = (u32)(((((s64)p_adc * sens) >> 21) - off) >> 15);
return 0;
}
EXPORT_SYMBOL_NS(ms_sensors_read_temp_and_pressure, IIO_MEAS_SPEC_SENSORS);
MODULE_DESCRIPTION("Measurement-Specialties common i2c driver");
MODULE_AUTHOR("William Markezana <[email protected]>");
MODULE_AUTHOR("Ludovic Tancerel <[email protected]>");
MODULE_LICENSE("GPL v2");
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