From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: MIME-Version: 1.0 In-Reply-To: References: <1438248345-25820-1-git-send-email-ludovic.tancerel@maplehightech.com> <1438248345-25820-2-git-send-email-ludovic.tancerel@maplehightech.com> <55C6351C.7090404@kernel.org> From: Crt Mori Date: Mon, 10 Aug 2015 13:07:21 +0200 Message-ID: Subject: Re: [PATCH V2 1/6] iio: Add meas-spec sensors common part To: Jonathan Cameron Cc: Ludovic Tancerel , Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald , linux-iio@vger.kernel.org, William.Markezana@meas-spec.com Content-Type: text/plain; charset=UTF-8 List-ID: On 10 August 2015 at 09:43, Crt Mori wrote: > On 8 August 2015 at 18:58, Jonathan Cameron wrote: >> On 30/07/15 10:25, Ludovic Tancerel wrote: >>> Signed-off-by: Ludovic Tancerel >> A few bits inline. >> Also, would prefer some basic description of the patch up here... >>> --- >>> drivers/iio/common/Kconfig | 1 + >>> drivers/iio/common/Makefile | 1 + >>> drivers/iio/common/ms_sensors/Kconfig | 6 + >>> drivers/iio/common/ms_sensors/Makefile | 5 + >>> drivers/iio/common/ms_sensors/ms_sensors_i2c.c | 634 +++++++++++++++++++++++++ >>> drivers/iio/common/ms_sensors/ms_sensors_i2c.h | 54 +++ >>> 6 files changed, 701 insertions(+) >>> create mode 100644 drivers/iio/common/ms_sensors/Kconfig >>> create mode 100644 drivers/iio/common/ms_sensors/Makefile >>> create mode 100644 drivers/iio/common/ms_sensors/ms_sensors_i2c.c >>> create mode 100644 drivers/iio/common/ms_sensors/ms_sensors_i2c.h >>> >>> diff --git a/drivers/iio/common/Kconfig b/drivers/iio/common/Kconfig >>> index 790f106..26a6026 100644 >>> --- a/drivers/iio/common/Kconfig >>> +++ b/drivers/iio/common/Kconfig >>> @@ -3,5 +3,6 @@ >>> # >>> >>> source "drivers/iio/common/hid-sensors/Kconfig" >>> +source "drivers/iio/common/ms_sensors/Kconfig" >>> source "drivers/iio/common/ssp_sensors/Kconfig" >>> source "drivers/iio/common/st_sensors/Kconfig" >>> diff --git a/drivers/iio/common/Makefile b/drivers/iio/common/Makefile >>> index b1e4d9c..585da6a 100644 >>> --- a/drivers/iio/common/Makefile >>> +++ b/drivers/iio/common/Makefile >>> @@ -8,5 +8,6 @@ >>> >>> # When adding new entries keep the list in alphabetical order >>> obj-y += hid-sensors/ >>> +obj-y += ms_sensors/ >>> obj-y += ssp_sensors/ >>> obj-y += st_sensors/ >>> diff --git a/drivers/iio/common/ms_sensors/Kconfig b/drivers/iio/common/ms_sensors/Kconfig >>> new file mode 100644 >>> index 0000000..b28a92b >>> --- /dev/null >>> +++ b/drivers/iio/common/ms_sensors/Kconfig >>> @@ -0,0 +1,6 @@ >>> +# >>> +# Measurements Specialties sensors common library >>> +# >>> + >>> +config IIO_MS_SENSORS_I2C >>> + tristate >>> diff --git a/drivers/iio/common/ms_sensors/Makefile b/drivers/iio/common/ms_sensors/Makefile >>> new file mode 100644 >>> index 0000000..7846428 >>> --- /dev/null >>> +++ b/drivers/iio/common/ms_sensors/Makefile >>> @@ -0,0 +1,5 @@ >>> +# >>> +# Makefile for the Measurement Specialties sensor common modules. >>> +# >>> + >>> +obj-$(CONFIG_IIO_MS_SENSORS_I2C) += ms_sensors_i2c.o >>> 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 0000000..f5d27b6 >>> --- /dev/null >>> +++ b/drivers/iio/common/ms_sensors/ms_sensors_i2c.c >>> @@ -0,0 +1,634 @@ >>> +/* >>> + * Measurements Specialties driver common i2c functions >>> + * >>> + * Copyright (c) 2015 Measurement-Specialties >>> + * >>> + * Licensed under the GPL-2. >>> + * >>> + */ >>> + >>> +#include >>> +#include >>> +#include >>> +#include >>> + >>> +#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_USER_REG_WRITE 0xE6 >>> +#define MS_SENSORS_USER_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_i2c_reset() - i2c reset function >>> + * @cli: pointer on i2c 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_i2c_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_i2c_reset); >>> + >>> +/** >>> + * ms_sensors_i2c_read_prom_word() - i2c prom word read function >>> + * @cli: pointer on i2c client >>> + * @cmd: PROM read cmd. Depends on device and prom id >>> + * @word: pointer on word destination value >>> + * >>> + * Generic i2c prom word read function for Measurement Specialties devices >>> + * >>> + * Return: 0 on success, negative errno otherwise. >>> + */ >>> +int ms_sensors_i2c_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_i2c_read_prom_word); >>> + >>> +/** >>> + * ms_sensors_i2c_convert_and_read() - i2c ADC conversion & read function >>> + * @cli: pointer on i2c 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 on ADC destination value >>> + * >>> + * Generic i2c 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_i2c_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_i2c_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_i2c_read_serial() - i2c serial number read function >>> + * @cli: pointer on i2c client >>> + * @sn: pointer on 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 >>> + * >>> + * Return: 0 on success, negative errno otherwise. >>> + */ >>> +int ms_sensors_i2c_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 = (char *)&send_buf, >> If you are going to type cast, please match the (__u8 *) from >> include/uapi/linux/i2c.h > I am trying to push similar function (i2c_addressed_read) to i2c interface and > since this driver has created its own instance of it, I would prefer > we put it into > i2c-core.c . Could you please support that debate [1] ? I think there are quite > many drivers out there using the same function in a various way and it is > about time to have it included in i2c to have more uniform control. You should use: regmap_i2c_read (#include ) >>> + }, >>> + { >>> + .addr = client->addr, >>> + .flags = client->flags | I2C_M_RD, >>> + .buf = (char *)&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) >>> + goto err; >>> + >>> + 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) >>> + goto err; >>> + >>> + 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; >>> + >>> +err: >> Put this inline and drop the goto >>> + dev_err(&client->dev, "Unable to read device serial number"); >>> + return ret; >>> +} >>> +EXPORT_SYMBOL(ms_sensors_i2c_read_serial); >>> + >> What is meant by a user_reg as opposed to other regs? >>> +static int ms_sensors_i2c_read_user_reg(struct i2c_client *client, >>> + u8 *user_reg) >>> +{ >>> + int ret; >>> + >>> + ret = i2c_smbus_write_byte(client, MS_SENSORS_USER_REG_READ); >>> + if (ret) >>> + goto err; >>> + >>> + ret = i2c_master_recv(client, user_reg, 1); >>> + if (ret < 0) >>> + goto err; >>> + dev_dbg(&client->dev, "User register :%x\n", *user_reg); >>> + >>> + return 0; >>> +err: >>> + dev_err(&client->dev, "Unable to read user reg"); >>> + return ret; >>> +} >>> + >>> +/** >>> + * ms_sensors_i2c_write_resolution() - set resolution i2c function >>> + * @dev_data: pointer on temperature/humidity device data >>> + * @i: resolution index to set >>> + * >>> + * That function will program the appropriate resolution based on the index >>> + * provided when user space will set samp_freq channel. >>> + * That function is used for TSYS02D, HTU21 and MS8607 chipsets >>> + * >>> + * Return: 0 on success, negative errno otherwise. >>> + */ >>> +ssize_t ms_sensors_i2c_write_resolution(struct ms_ht_dev *dev_data, >>> + u8 i) >>> +{ >>> + u8 user_reg; >>> + int ret; >>> + >>> + ret = ms_sensors_i2c_read_user_reg(dev_data->client, &user_reg); >>> + if (ret) >>> + return ret; >>> + >>> + user_reg &= 0x7E; >>> + user_reg |= ((i & 1) << 7) + ((i & 2) >> 1); >>> + >>> + return i2c_smbus_write_byte_data(dev_data->client, >>> + MS_SENSORS_USER_REG_WRITE, >>> + user_reg); >>> +} >>> +EXPORT_SYMBOL(ms_sensors_i2c_write_resolution); >>> + >>> +/** >>> + * ms_sensors_i2c_show_battery_low() - show device battery low indicator >>> + * @dev_data: pointer on temperature/humidity device data >>> + * @buf: pointer on char buffer to write result >>> + * >>> + * That function will read battery indicator value in the device and >>> + * return 1 if the device voltage is below 2.25V. >>> + * That function is used for TSYS02D, HTU21 and MS8607 chipsets >>> + * >>> + * Return: length of sprintf on success, negative errno otherwise. >>> + */ >>> +ssize_t ms_sensors_i2c_show_battery_low(struct ms_ht_dev *dev_data, >>> + char *buf) >>> +{ >>> + int ret; >>> + u8 user_reg; >>> + >>> + mutex_lock(&dev_data->lock); >>> + ret = ms_sensors_i2c_read_user_reg(dev_data->client, &user_reg); >>> + mutex_unlock(&dev_data->lock); >>> + if (ret) >>> + return ret; >>> + >>> + return sprintf(buf, "%d\n", (user_reg & 0x40) >> 6); >>> +} >>> +EXPORT_SYMBOL(ms_sensors_i2c_show_battery_low); >>> + >>> +/** >>> + * ms_sensors_i2c_show_heater() - show device heater >>> + * @dev_data: pointer on temperature/humidity device data >>> + * @buf: pointer on char buffer to write result >>> + * >>> + * That function will read heater enable value in the device and >>> + * return 1 if the heater is enabled >>> + * That function is used for HTU21 and MS8607 chipsets >>> + * >>> + * Return: length of sprintf on success, negative errno otherwise. >>> + */ >>> +ssize_t ms_sensors_i2c_show_heater(struct ms_ht_dev *dev_data, >>> + char *buf) >>> +{ >>> + u8 user_reg; >>> + int ret; >>> + >>> + mutex_lock(&dev_data->lock); >>> + ret = ms_sensors_i2c_read_user_reg(dev_data->client, &user_reg); >>> + mutex_unlock(&dev_data->lock); >>> + if (ret) >>> + return ret; >>> + >>> + return sprintf(buf, "%d\n", (user_reg & 0x4) >> 2); >>> +} >>> +EXPORT_SYMBOL(ms_sensors_i2c_show_heater); >>> + >>> +/** >>> + * ms_sensors_i2c_write_heater() - write device heater >> I'm not sure the _i2c_ bit is important in this function name... >> >>> + * @dev_data: pointer on temperature/humidity device data >>> + * @buf: pointer on char buffer from user space >>> + * @len: length of buf >>> + * >>> + * That function will write 1 or 0 value in the device >>> + * to enable or disable heater >>> + * That function is used for HTU21 and MS8607 chipsets >> That->This >>> + * >>> + * Return: length of buffer, negative errno otherwise. >>> + */ >>> +ssize_t ms_sensors_i2c_write_heater(struct ms_ht_dev *dev_data, >>> + const char *buf, size_t len) >>> +{ >>> + u8 val, user_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_i2c_read_user_reg(dev_data->client, &user_reg); >>> + if (ret) { >>> + mutex_unlock(&dev_data->lock); >>> + return ret; >>> + } >>> + >>> + user_reg &= 0xFB; >>> + user_reg |= val << 2; >>> + >>> + ret = i2c_smbus_write_byte_data(dev_data->client, >>> + MS_SENSORS_USER_REG_WRITE, >>> + user_reg); >>> + mutex_unlock(&dev_data->lock); >>> + if (ret) { >>> + dev_err(&dev_data->client->dev, "Unable to write user reg\n"); >>> + return ret; >>> + } >>> + >>> + return len; >>> +} >>> +EXPORT_SYMBOL(ms_sensors_i2c_write_heater); >>> + >>> +/** >>> + * ms_sensors_i2c_ht_read_temperature() - i2c read temperature >>> + * @dev_data: pointer on temperature/humidity device data >>> + * @temperature:pointer on temperature destination value >>> + * >>> + * That function will get temperature ADC value from the device, >>> + * check the CRC and compute the temperature value. >>> + * That function is used for TSYS02D, HTU21 and MS8607 chipsets >>> + * >>> + * Return: 0 on success, negative errno otherwise. >>> + */ >>> +int ms_sensors_i2c_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_i2c_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_i2c_ht_read_temperature); >>> + >>> +/** >>> + * ms_sensors_i2c_ht_read_humidity() - i2c read humidity >>> + * @dev_data: pointer on temperature/humidity device data >>> + * @humidity: pointer on humidity destination value >>> + * >>> + * That function will get humidity ADC value from the device, >>> + * check the CRC and compute the temperature value. >>> + * That function is used for HTU21 and MS8607 chipsets >>> + * >>> + * Return: 0 on success, negative errno otherwise. >>> + */ >>> +int ms_sensors_i2c_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_i2c_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_i2c_ht_read_humidity); >>> + >> Multiline comment syntax is >> /* >> * CRC... >> */ >> Or ideally use kernel-doc as you have for other functions below >> (not required as not exported) >> >>> +/* CRC check function for Temperature and pressure devices >>> + * That function is only used when reading PROM coefficients */ >>> +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 on temperature/pressure device data >> pointer to temperature/... (fix throughout driver please) >>> + * >>> + * That function will read prom coefficients and check CRC >> That -> This (and add a full stop at the end of the sentence. >>> + * That 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_i2c_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 on temperature/pressure device data >> pointer to >>> + * @temperature:pointer on temperature destination value >> pointer to (also missing tab?) >>> + * @pressure: pointer on pressure destination value >>> + * >>> + * That function will read ADC and compute pressure and temperature value >> That->This and full stop at end of sentence. >> >>> + * That 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; >>> + u8 i; >>> + >>> + mutex_lock(&dev_data->lock); >>> + i = dev_data->res_index * 2; >>> + delay = ms_sensors_tp_conversion_time[dev_data->res_index]; >> Blank line here would improve readability. >>> + ret = ms_sensors_i2c_convert_and_read( >>> + dev_data->client, >>> + MS_SENSORS_TP_T_CONVERSION_START + i, >>> + MS_SENSORS_TP_ADC_READ, >>> + delay, &t_adc); >>> + if (ret) { >>> + mutex_unlock(&dev_data->lock); >>> + return ret; >>> + } >> blank line here. >>> + ret = ms_sensors_i2c_convert_and_read( >>> + dev_data->client, >>> + MS_SENSORS_TP_P_CONVERSION_START + i, >>> + 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 "); >>> +MODULE_AUTHOR("Ludovic Tancerel "); >>> +MODULE_LICENSE("GPL v2"); >>> + >>> diff --git a/drivers/iio/common/ms_sensors/ms_sensors_i2c.h b/drivers/iio/common/ms_sensors/ms_sensors_i2c.h >>> new file mode 100644 >>> index 0000000..a521428 >>> --- /dev/null >>> +++ b/drivers/iio/common/ms_sensors/ms_sensors_i2c.h >>> @@ -0,0 +1,54 @@ >>> +/* >>> + * Measurements Specialties common sensor driver >>> + * >>> + * Copyright (c) 2015 Measurement-Specialties >>> + * >>> + * This program is free software; you can redistribute it and/or modify >>> + * it under the terms of the GNU General Public License version 2 as >>> + * published by the Free Software Foundation. >>> + * >> Unnecesary blank line here. >>> + */ >>> + >>> +#ifndef _MS_SENSORS_I2C_H >>> +#define _MS_SENSORS_I2C_H >>> + >>> +#include >>> +#include >>> + >>> +#define MS_SENSORS_TP_PROM_WORDS_NB 7 >>> + >>> +struct ms_ht_dev { >>> + struct i2c_client *client; >>> + struct mutex lock; /* mutex protecting data structure */ >>> + u8 res_index; >>> +}; >>> + >>> +struct ms_tp_dev { >>> + struct i2c_client *client; >>> + struct mutex lock; /* mutex protecting data structure */ >>> + /* Added element for CRC computation */ >>> + u16 prom[MS_SENSORS_TP_PROM_WORDS_NB + 1]; >>> + u8 res_index; >>> +}; >>> + >>> +int ms_sensors_i2c_reset(void *cli, u8 cmd, unsigned int delay); >>> +int ms_sensors_i2c_read_prom_word(void *cli, int cmd, u16 *word); >>> +int ms_sensors_i2c_convert_and_read(void *cli, u8 conv, u8 rd, >>> + unsigned int delay, u32 *adc); >>> +int ms_sensors_i2c_read_serial(struct i2c_client *client, u64 *sn); >>> +ssize_t ms_sensors_i2c_show_serial(struct ms_ht_dev *dev_data, char *buf); >>> +ssize_t ms_sensors_i2c_write_resolution(struct ms_ht_dev *dev_data, u8 i); >>> +ssize_t ms_sensors_i2c_show_battery_low(struct ms_ht_dev *dev_data, char *buf); >>> +ssize_t ms_sensors_i2c_show_heater(struct ms_ht_dev *dev_data, char *buf); >>> +ssize_t ms_sensors_i2c_write_heater(struct ms_ht_dev *dev_data, >>> + const char *buf, size_t len); >>> +int ms_sensors_i2c_ht_read_temperature(struct ms_ht_dev *dev_data, >>> + s32 *temperature); >>> +int ms_sensors_i2c_ht_read_humidity(struct ms_ht_dev *dev_data, >>> + u32 *humidity); >>> +int ms_sensors_tp_read_prom(struct ms_tp_dev *dev_data); >>> +int ms_sensors_read_temp_and_pressure(struct ms_tp_dev *dev_data, >>> + int *temperature, >>> + unsigned int *pressure); >>> + >>> +#endif /* _MS_SENSORS_I2C_H */ >>> >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-iio" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html > > [1] http://comments.gmane.org/gmane.linux.drivers.i2c/23906