diff options
Diffstat (limited to 'drivers/iio/common/ms_sensors/ms_sensors_i2c.c')
| -rw-r--r-- | drivers/iio/common/ms_sensors/ms_sensors_i2c.c | 652 |
1 files changed, 652 insertions, 0 deletions
diff --git a/drivers/iio/common/ms_sensors/ms_sensors_i2c.c b/drivers/iio/common/ms_sensors/ms_sensors_i2c.c new file mode 100644 index 000000000000..669dc7c270f5 --- /dev/null +++ b/drivers/iio/common/ms_sensors/ms_sensors_i2c.c @@ -0,0 +1,652 @@ +/* + * 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; + __be32 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; + __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(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"); + |