--- /dev/null
+/*
+ * Measurements Specialties driver common i2c functions
+ *
+ * Copyright (c) 2015 Measurement-Specialties
+ *
+ * Licensed under the GPL-2.
+ */
+
+#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, 3000,
+ 5000, 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(ms_sensors_reset);
+
+/**
+ * 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 = (struct i2c_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(ms_sensors_read_prom_word);
+
+/**
+ * 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;
+ u32 buf = 0;
+ struct i2c_client *client = (struct i2c_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(ms_sensors_convert_and_read);
+
+/**
+ * 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
+ * @cli: 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;
+ u64 rcv_buf = 0;
+ u16 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_buf = be64_to_cpu(rcv_buf);
+ dev_dbg(&client->dev, "Serial MSB raw : %llx\n", rcv_buf);
+
+ for (i = 0; i < 64; i += 16) {
+ if (!ms_sensors_crc_valid((rcv_buf >> i) & 0xFFFF))
+ return -ENODEV;
+ }
+
+ *sn = (((rcv_buf >> 32) & 0xFF000000) |
+ ((rcv_buf >> 24) & 0x00FF0000) |
+ ((rcv_buf >> 16) & 0x0000FF00) |
+ ((rcv_buf >> 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_buf = be64_to_cpu(rcv_buf) >> 16;
+ dev_dbg(&client->dev, "Serial MSB raw : %llx\n", rcv_buf);
+
+ for (i = 0; i < 48; i += 24) {
+ if (!ms_sensors_crc_valid((rcv_buf >> i) & 0xFFFFFF))
+ return -ENODEV;
+ }
+
+ *sn |= (rcv_buf & 0xFFFF00) << 40 | (rcv_buf >> 32);
+
+ return 0;
+}
+EXPORT_SYMBOL(ms_sensors_read_serial);
+
+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(ms_sensors_write_resolution);
+
+/**
+ * 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 sprintf(buf, "%d\n", (config_reg & 0x40) >> 6);
+}
+EXPORT_SYMBOL(ms_sensors_show_battery_low);
+
+/**
+ * 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 sprintf(buf, "%d\n", (config_reg & 0x4) >> 2);
+}
+EXPORT_SYMBOL(ms_sensors_show_heater);
+
+/**
+ * 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(ms_sensors_write_heater);
+
+/**
+ * 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(ms_sensors_ht_read_temperature);
+
+/**
+ * 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(ms_sensors_ht_read_humidity);
+
+/**
+ * ms_sensors_tp_crc_valid() - CRC check function for
+ * Temperature and pressure devices.
+ * This function is only used when reading PROM coefficients
+ *
+ * @prom: pointer to PROM coefficients array
+ * @len: length of PROM coefficients array
+ *
+ * Return: True if CRC is ok.
+ */
+static bool ms_sensors_tp_crc_valid(u16 *prom, u8 len)
+{
+ unsigned int cnt, n_bit;
+ u16 n_rem = 0x0000, crc_read = prom[0], crc = (*prom & 0xF000) >> 12;
+
+ prom[len - 1] = 0;
+ prom[0] &= 0x0FFF; /* Clear the CRC computation part */
+
+ for (cnt = 0; cnt < len * 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;
+ }
+ }
+ n_rem >>= 12;
+ prom[0] = crc_read;
+
+ return n_rem == crc;
+}
+
+/**
+ * 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;
+
+ for (i = 0; i < MS_SENSORS_TP_PROM_WORDS_NB; 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 (!ms_sensors_tp_crc_valid(dev_data->prom,
+ MS_SENSORS_TP_PROM_WORDS_NB + 1)) {
+ dev_err(&dev_data->client->dev,
+ "Calibration coefficients crc check error\n");
+ return -ENODEV;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(ms_sensors_tp_read_prom);
+
+/**
+ * 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(ms_sensors_read_temp_and_pressure);
+
+MODULE_DESCRIPTION("Measurement-Specialties common i2c driver");
+MODULE_AUTHOR("William Markezana <william.markezana@meas-spec.com>");
+MODULE_AUTHOR("Ludovic Tancerel <ludovic.tancerel@maplehightech.com>");
+MODULE_LICENSE("GPL v2");
+
projects / linux-beck.git / commitdiff