1 /* Copyright 2018 Jack Humbert
2 * Copyright 2018 Yiancar
4 * This program is free software: you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation, either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 /* This library is only valid for STM32 processors.
19 * This library follows the convention of the AVR i2c_master library.
20 * As a result addresses are expected to be already shifted (addr << 1).
21 * I2CD1 is the default driver which corresponds to pins B6 and B7. This
23 * Please ensure that HAL_USE_I2C is TRUE in the halconf.h file and that
24 * STM32_I2C_USE_I2C1 is TRUE in the mcuconf.h file. Pins B6 and B7 are used
25 * but using any other I2C pins should be trivial.
28 #include "i2c_master.h"
35 static uint8_t i2c_address;
37 // This configures the I2C clock to 400khz assuming a 48Mhz clock
38 // For more info : https://www.st.com/en/embedded-software/stsw-stm32126.html
39 static const I2CConfig i2cconfig = {
40 STM32_TIMINGR_PRESC(0x00U) |
41 STM32_TIMINGR_SCLDEL(0x03U) | STM32_TIMINGR_SDADEL(0x01U) |
42 STM32_TIMINGR_SCLH(0x03U) | STM32_TIMINGR_SCLL(0x09U),
47 __attribute__ ((weak))
50 // Try releasing special pins for a short time
51 palSetPadMode(GPIOB, 6, PAL_MODE_INPUT);
52 palSetPadMode(GPIOB, 7, PAL_MODE_INPUT);
54 chThdSleepMilliseconds(10);
56 palSetPadMode(GPIOB, 6, PAL_MODE_ALTERNATE(1) | PAL_STM32_OTYPE_OPENDRAIN);
57 palSetPadMode(GPIOB, 7, PAL_MODE_ALTERNATE(1) | PAL_STM32_OTYPE_OPENDRAIN);
59 //i2cInit(); //This is invoked by halInit() so no need to redo it.
62 // This is usually not needed
63 uint8_t i2c_start(uint8_t address)
65 i2c_address = address;
66 i2cStart(&I2C_DRIVER, &i2cconfig);
70 uint8_t i2c_transmit(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout)
72 msg_t status = MSG_OK;
74 i2c_address = address;
75 i2cStart(&I2C_DRIVER, &i2cconfig);
76 i2cAcquireBus(&I2C_DRIVER);
77 status = i2cMasterTransmitTimeout(&I2C_DRIVER, (i2c_address >> 1), data, length, 0, 0, MS2ST(timeout));
78 i2cReleaseBus(&I2C_DRIVER);
82 uint8_t i2c_receive(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout)
84 i2c_address = address;
85 i2cStart(&I2C_DRIVER, &i2cconfig);
86 return i2cMasterReceiveTimeout(&I2C_DRIVER, (i2c_address >> 1), data, length, MS2ST(timeout));
89 uint8_t i2c_writeReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout)
91 i2c_address = devaddr;
92 i2cStart(&I2C_DRIVER, &i2cconfig);
94 uint8_t complete_packet[length + 1];
95 for(uint8_t i = 0; i < length; i++)
97 complete_packet[i+1] = data[i];
99 complete_packet[0] = regaddr;
101 return i2cMasterTransmitTimeout(&I2C_DRIVER, (i2c_address >> 1), complete_packet, length + 1, 0, 0, MS2ST(timeout));
104 uint8_t i2c_readReg(uint8_t devaddr, uint8_t* regaddr, uint8_t* data, uint16_t length, uint16_t timeout)
106 i2c_address = devaddr;
107 i2cStart(&I2C_DRIVER, &i2cconfig);
108 return i2cMasterTransmitTimeout(&I2C_DRIVER, (i2c_address >> 1), regaddr, 1, data, length, MS2ST(timeout));
111 // This is usually not needed. It releases the driver to allow pins to become GPIO again.
112 uint8_t i2c_stop(void)
114 i2cStop(&I2C_DRIVER);