2 * Copyright (C) 2018 - 2019 Bosch Sensortec GmbH
\r
4 * Redistribution and use in source and binary forms, with or without
\r
5 * modification, are permitted provided that the following conditions are met:
\r
7 * Redistributions of source code must retain the above copyright
\r
8 * notice, this list of conditions and the following disclaimer.
\r
10 * Redistributions in binary form must reproduce the above copyright
\r
11 * notice, this list of conditions and the following disclaimer in the
\r
12 * documentation and/or other materials provided with the distribution.
\r
14 * Neither the name of the copyright holder nor the names of the
\r
15 * contributors may be used to endorse or promote products derived from
\r
16 * this software without specific prior written permission.
\r
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
\r
19 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
\r
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
\r
21 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
\r
22 * DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDER
\r
23 * OR CONTRIBUTORS BE LIABLE FOR ANY
\r
24 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
\r
25 * OR CONSEQUENTIAL DAMAGES(INCLUDING, BUT NOT LIMITED TO,
\r
26 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
\r
27 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
\r
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
\r
29 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
\r
30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
\r
31 * ANY WAY OUT OF THE USE OF THIS
\r
32 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE
\r
34 * The information provided is believed to be accurate and reliable.
\r
35 * The copyright holder assumes no responsibility
\r
36 * for the consequences of use
\r
37 * of such information nor for any infringement of patents or
\r
38 * other rights of third parties which may result from its use.
\r
39 * No license is granted by implication or otherwise under any patent or
\r
40 * patent rights of the copyright holder.
\r
42 * File bme280_selftest.c
\r
48 #include "bme280_selftest.h"
\r
50 #define BME280_CRC_DATA_ADDR UINT8_C(0xE8)
\r
51 #define BME280_CRC_DATA_LEN UINT8_C(1)
\r
52 #define BME280_CRC_CALIB1_ADDR UINT8_C(0x88)
\r
53 #define BME280_CRC_CALIB1_LEN UINT8_C(26)
\r
54 #define BME280_CRC_CALIB2_ADDR UINT8_C(0xE1)
\r
55 #define BME280_CRC_CALIB2_LEN UINT8_C(7)
\r
58 * @brief This API calculates the CRC
\r
60 * @param[in] mem_values : reg_data parameter to calculate CRC
\r
61 * @param[in] mem_length : Parameter to calculate CRC
\r
63 * @return Result of API execution status
\r
64 * @retval zero -> Success / +ve value -> Warning / -ve value -> Error
\r
66 static uint8_t crc_calculate(uint8_t *mem_values, uint8_t mem_length);
\r
69 * @brief This API reads the stored CRC and then compare with calculated CRC
\r
71 * @param[in] dev : Structure instance of bme280_dev.
\r
73 * @return Result of API execution status
\r
74 * @retval zero -> self test success / +ve value -> warning(self test fail)
\r
76 int8_t bme280_crc_selftest(const struct bme280_dev *dev)
\r
80 uint8_t reg_data[64];
\r
81 uint8_t stored_crc = 0;
\r
82 uint8_t calculated_crc = 0;
\r
84 /* Read stored crc value from register */
\r
85 reg_addr = BME280_CRC_DATA_ADDR;
\r
86 rslt = bme280_get_regs(reg_addr, reg_data, BME280_CRC_DATA_LEN, dev);
\r
87 if (rslt == BME280_OK)
\r
89 stored_crc = reg_data[0];
\r
91 /* Calculated CRC value with calibration register */
\r
92 reg_addr = BME280_CRC_CALIB1_ADDR;
\r
93 rslt = bme280_get_regs(reg_addr, ®_data[0], BME280_CRC_CALIB1_LEN, dev);
\r
94 if (rslt == BME280_OK)
\r
96 reg_addr = BME280_CRC_CALIB2_ADDR;
\r
97 rslt = bme280_get_regs(reg_addr, ®_data[BME280_CRC_CALIB1_LEN], BME280_CRC_CALIB2_LEN, dev);
\r
98 if (rslt == BME280_OK)
\r
100 calculated_crc = crc_calculate(reg_data, BME280_CRC_CALIB1_LEN + BME280_CRC_CALIB2_LEN);
\r
103 if (stored_crc == calculated_crc)
\r
109 rslt = BME280_W_SELF_TEST_FAIL;
\r
119 * @brief This API calculates the CRC
\r
121 * @param[in] mem_values : reg_data parameter to calculate CRC
\r
122 * @param[in] mem_length : Parameter to calculate CRC
\r
124 * @return Result of API execution status
\r
125 * @retval zero -> Success / +ve value -> Warning / -ve value -> Error
\r
127 static uint8_t crc_calculate(uint8_t *mem_values, uint8_t mem_length)
\r
129 uint32_t crc_reg = 0xFF;
\r
130 uint8_t polynomial = 0x1D;
\r
131 uint8_t bitNo, index;
\r
134 for (index = 0; index < mem_length; index++)
\r
136 for (bitNo = 0; bitNo < 8; bitNo++)
\r
138 if (((crc_reg & 0x80) > 0) != ((mem_values[index] & 0x80) > 0))
\r
147 /* Truncate 8th bit for crc_reg and mem_values */
\r
148 crc_reg = (uint32_t)((crc_reg & 0x7F) << 1);
\r
149 mem_values[index] = (uint8_t)((mem_values[index] & 0x7F) << 1);
\r
150 crc_reg = (uint32_t)(crc_reg ^ (polynomial * din));
\r
154 return (uint8_t)(crc_reg ^ 0xFF);
\r