On 8 August 2015 at 18:58, Jonathan Cameron <jic23@xxxxxxxxxx> wrote:
> On 30/07/15 10:25, Ludovic Tancerel wrote:
>> Signed-off-by: Ludovic Tancerel <ludovic.tancerel@xxxxxxxxxxxxxxxxx>
> 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 <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_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.
>> + },
>> + {
>> + .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 <william.markezana@xxxxxxxxxxxxx>");
>> +MODULE_AUTHOR("Ludovic Tancerel <ludovic.tancerel@xxxxxxxxxxxxxxxxx>");
>> +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 <linux/i2c.h>
>> +#include <linux/mutex.h>
>> +
>> +#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 */
>>
>
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[1] http://comments.gmane.org/gmane.linux.drivers.i2c/23906
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