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sensirion_i2c.c
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sensirion_i2c.c
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/*
* Copyright (c) 2018, Sensirion AG
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* * Neither the name of Sensirion AG nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include "sensirion_i2c.h"
#include "sensirion_common.h"
#include "sensirion_config.h"
#include "sensirion_i2c_hal.h"
uint8_t sensirion_i2c_generate_crc(const uint8_t* data, uint16_t count) {
uint16_t current_byte;
uint8_t crc = CRC8_INIT;
uint8_t crc_bit;
/* calculates 8-Bit checksum with given polynomial */
for (current_byte = 0; current_byte < count; ++current_byte) {
crc ^= (data[current_byte]);
for (crc_bit = 8; crc_bit > 0; --crc_bit) {
if (crc & 0x80)
crc = (crc << 1) ^ CRC8_POLYNOMIAL;
else
crc = (crc << 1);
}
}
return crc;
}
int8_t sensirion_i2c_check_crc(const uint8_t* data, uint16_t count,
uint8_t checksum) {
if (sensirion_i2c_generate_crc(data, count) != checksum)
return CRC_ERROR;
return NO_ERROR;
}
int16_t sensirion_i2c_general_call_reset(void) {
const uint8_t data = 0x06;
return sensirion_i2c_hal_write(0, &data, (uint16_t)sizeof(data));
}
uint16_t sensirion_i2c_fill_cmd_send_buf(uint8_t* buf, uint16_t cmd,
const uint16_t* args,
uint8_t num_args) {
uint8_t i;
uint16_t idx = 0;
buf[idx++] = (uint8_t)((cmd & 0xFF00) >> 8);
buf[idx++] = (uint8_t)((cmd & 0x00FF) >> 0);
for (i = 0; i < num_args; ++i) {
buf[idx++] = (uint8_t)((args[i] & 0xFF00) >> 8);
buf[idx++] = (uint8_t)((args[i] & 0x00FF) >> 0);
uint8_t crc = sensirion_i2c_generate_crc((uint8_t*)&buf[idx - 2],
SENSIRION_WORD_SIZE);
buf[idx++] = crc;
}
return idx;
}
int16_t sensirion_i2c_read_words_as_bytes(uint8_t address, uint8_t* data,
uint16_t num_words) {
int16_t ret;
uint16_t i, j;
uint16_t size = num_words * (SENSIRION_WORD_SIZE + CRC8_LEN);
uint16_t word_buf[SENSIRION_MAX_BUFFER_WORDS];
uint8_t* const buf8 = (uint8_t*)word_buf;
ret = sensirion_i2c_hal_read(address, buf8, size);
if (ret != NO_ERROR)
return ret;
/* check the CRC for each word */
for (i = 0, j = 0; i < size; i += SENSIRION_WORD_SIZE + CRC8_LEN) {
ret = sensirion_i2c_check_crc(&buf8[i], SENSIRION_WORD_SIZE,
buf8[i + SENSIRION_WORD_SIZE]);
if (ret != NO_ERROR)
return ret;
data[j++] = buf8[i];
data[j++] = buf8[i + 1];
}
return NO_ERROR;
}
int16_t sensirion_i2c_read_words(uint8_t address, uint16_t* data_words,
uint16_t num_words) {
int16_t ret;
uint8_t i;
ret = sensirion_i2c_read_words_as_bytes(address, (uint8_t*)data_words,
num_words);
if (ret != NO_ERROR)
return ret;
for (i = 0; i < num_words; ++i) {
const uint8_t* word_bytes = (uint8_t*)&data_words[i];
data_words[i] = ((uint16_t)word_bytes[0] << 8) | word_bytes[1];
}
return NO_ERROR;
}
int16_t sensirion_i2c_write_cmd(uint8_t address, uint16_t command) {
uint8_t buf[SENSIRION_COMMAND_SIZE];
sensirion_i2c_fill_cmd_send_buf(buf, command, NULL, 0);
return sensirion_i2c_hal_write(address, buf, SENSIRION_COMMAND_SIZE);
}
int16_t sensirion_i2c_write_cmd_with_args(uint8_t address, uint16_t command,
const uint16_t* data_words,
uint16_t num_words) {
uint8_t buf[SENSIRION_MAX_BUFFER_WORDS];
uint16_t buf_size;
buf_size =
sensirion_i2c_fill_cmd_send_buf(buf, command, data_words, num_words);
return sensirion_i2c_hal_write(address, buf, buf_size);
}
int16_t sensirion_i2c_delayed_read_cmd(uint8_t address, uint16_t cmd,
uint32_t delay_us, uint16_t* data_words,
uint16_t num_words) {
int16_t ret;
uint8_t buf[SENSIRION_COMMAND_SIZE];
sensirion_i2c_fill_cmd_send_buf(buf, cmd, NULL, 0);
ret = sensirion_i2c_hal_write(address, buf, SENSIRION_COMMAND_SIZE);
if (ret != NO_ERROR)
return ret;
if (delay_us)
sensirion_i2c_hal_sleep_usec(delay_us);
return sensirion_i2c_read_words(address, data_words, num_words);
}
int16_t sensirion_i2c_read_cmd(uint8_t address, uint16_t cmd,
uint16_t* data_words, uint16_t num_words) {
return sensirion_i2c_delayed_read_cmd(address, cmd, 0, data_words,
num_words);
}
uint16_t sensirion_i2c_add_command_to_buffer(uint8_t* buffer, uint16_t offset,
uint16_t command) {
buffer[offset++] = (uint8_t)((command & 0xFF00) >> 8);
buffer[offset++] = (uint8_t)((command & 0x00FF) >> 0);
return offset;
}
uint16_t sensirion_i2c_add_uint32_t_to_buffer(uint8_t* buffer, uint16_t offset,
uint32_t data) {
buffer[offset++] = (uint8_t)((data & 0xFF000000) >> 24);
buffer[offset++] = (uint8_t)((data & 0x00FF0000) >> 16);
buffer[offset] = sensirion_i2c_generate_crc(
&buffer[offset - SENSIRION_WORD_SIZE], SENSIRION_WORD_SIZE);
offset++;
buffer[offset++] = (uint8_t)((data & 0x0000FF00) >> 8);
buffer[offset++] = (uint8_t)((data & 0x000000FF) >> 0);
buffer[offset] = sensirion_i2c_generate_crc(
&buffer[offset - SENSIRION_WORD_SIZE], SENSIRION_WORD_SIZE);
offset++;
return offset;
}
uint16_t sensirion_i2c_add_int32_t_to_buffer(uint8_t* buffer, uint16_t offset,
int32_t data) {
return sensirion_i2c_add_uint32_t_to_buffer(buffer, offset, (uint32_t)data);
}
uint16_t sensirion_i2c_add_uint16_t_to_buffer(uint8_t* buffer, uint16_t offset,
uint16_t data) {
buffer[offset++] = (uint8_t)((data & 0xFF00) >> 8);
buffer[offset++] = (uint8_t)((data & 0x00FF) >> 0);
buffer[offset] = sensirion_i2c_generate_crc(
&buffer[offset - SENSIRION_WORD_SIZE], SENSIRION_WORD_SIZE);
offset++;
return offset;
}
uint16_t sensirion_i2c_add_int16_t_to_buffer(uint8_t* buffer, uint16_t offset,
int16_t data) {
return sensirion_i2c_add_uint16_t_to_buffer(buffer, offset, (uint16_t)data);
}
uint16_t sensirion_i2c_add_float_to_buffer(uint8_t* buffer, uint16_t offset,
float data) {
union {
uint32_t uint32_data;
float float_data;
} convert;
convert.float_data = data;
buffer[offset++] = (uint8_t)((convert.uint32_data & 0xFF000000) >> 24);
buffer[offset++] = (uint8_t)((convert.uint32_data & 0x00FF0000) >> 16);
buffer[offset] = sensirion_i2c_generate_crc(
&buffer[offset - SENSIRION_WORD_SIZE], SENSIRION_WORD_SIZE);
offset++;
buffer[offset++] = (uint8_t)((convert.uint32_data & 0x0000FF00) >> 8);
buffer[offset++] = (uint8_t)((convert.uint32_data & 0x000000FF) >> 0);
buffer[offset] = sensirion_i2c_generate_crc(
&buffer[offset - SENSIRION_WORD_SIZE], SENSIRION_WORD_SIZE);
offset++;
return offset;
}
uint16_t sensirion_i2c_add_bytes_to_buffer(uint8_t* buffer, uint16_t offset,
const uint8_t* data,
uint16_t data_length) {
uint16_t i;
if (data_length % SENSIRION_WORD_SIZE != 0) {
return BYTE_NUM_ERROR;
}
for (i = 0; i < data_length; i += 2) {
buffer[offset++] = data[i];
buffer[offset++] = data[i + 1];
buffer[offset] = sensirion_i2c_generate_crc(
&buffer[offset - SENSIRION_WORD_SIZE], SENSIRION_WORD_SIZE);
offset++;
}
return offset;
}
int16_t sensirion_i2c_write_data(uint8_t address, const uint8_t* data,
uint16_t data_length) {
return sensirion_i2c_hal_write(address, data, data_length);
}
int16_t sensirion_i2c_read_data_inplace(uint8_t address, uint8_t* buffer,
uint16_t expected_data_length) {
int16_t error;
uint16_t i, j;
uint16_t size = (expected_data_length / SENSIRION_WORD_SIZE) *
(SENSIRION_WORD_SIZE + CRC8_LEN);
if (expected_data_length % SENSIRION_WORD_SIZE != 0) {
return BYTE_NUM_ERROR;
}
error = sensirion_i2c_hal_read(address, buffer, size);
if (error) {
return error;
}
for (i = 0, j = 0; i < size; i += SENSIRION_WORD_SIZE + CRC8_LEN) {
error = sensirion_i2c_check_crc(&buffer[i], SENSIRION_WORD_SIZE,
buffer[i + SENSIRION_WORD_SIZE]);
if (error) {
return error;
}
buffer[j++] = buffer[i];
buffer[j++] = buffer[i + 1];
}
return NO_ERROR;
}