i2c_master.c

/* Copyright 2018 Jack Humbert
 * Copyright 2018 Yiancar
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/* This library is only valid for STM32 processors.
 * This library follows the convention of the AVR i2c_master library.
 * As a result addresses are expected to be already shifted (addr << 1).
 * I2CD1 is the default driver which corresponds to pins B6 and B7. This
 * can be changed.
 * Please ensure that HAL_USE_I2C is TRUE in the halconf.h file and that
 * STM32_I2C_USE_I2C1 is TRUE in the mcuconf.h file. Pins B6 and B7 are used
 * but using any other I2C pins should be trivial.
 */
#include "i2c_master.h"
#include "quantum.h"
#include <string.h>
#include <hal.h>

static uint8_t i2c_address;

// This configures the I2C clock to 1mhz assuming a 72Mhz clock
static const I2CConfig i2cconfig = {
// This configures the I2C clock to 400khz assuming a 72Mhz clock
//   STM32_TIMINGR_PRESC(15U) |
//   STM32_TIMINGR_SCLDEL(4U) | STM32_TIMINGR_SDADEL(2U) |
//   STM32_TIMINGR_SCLH(15U)  | STM32_TIMINGR_SCLL(21U),
    0x00700E27,
    0,
    0
};
// 0x00C4092A also 1mhz?

static i2c_status_t chibios_to_qmk(const msg_t *status)
{
    switch (*status) {
        case I2C_NO_ERROR:
            return I2C_STATUS_SUCCESS;
        case I2C_TIMEOUT:
            return I2C_STATUS_TIMEOUT;
        // I2C_BUS_ERROR, I2C_ARBITRATION_LOST, I2C_ACK_FAILURE, I2C_OVERRUN, I2C_PEC_ERROR, I2C_SMB_ALERT
        default:
            return *status;
    }
}

__attribute__ ((weak))
void i2c_init(void)
{
    // Try releasing special pins for a short time
    palSetPadMode(I2C1_BANK, I2C1_SCL, PAL_MODE_INPUT);
    palSetPadMode(I2C1_BANK, I2C1_SDA, PAL_MODE_INPUT);

    chThdSleepMilliseconds(10);

    palSetPadMode(I2C1_BANK, I2C1_SCL, PAL_MODE_ALTERNATE(4) | PAL_STM32_OTYPE_OPENDRAIN);
    palSetPadMode(I2C1_BANK, I2C1_SDA, PAL_MODE_ALTERNATE(4) | PAL_STM32_OTYPE_OPENDRAIN);

    //i2cInit(); //This is invoked by halInit() so no need to redo it.
}

i2c_status_t i2c_start(uint8_t address)
{
    i2c_address = address;
    i2cStart(&I2C_DRIVER, &i2cconfig);
    return I2C_STATUS_SUCCESS;
}

i2c_status_t i2c_transmit(uint8_t address, const uint8_t *data, uint16_t length, uint16_t timeout)
{
    i2c_address = address;
    i2cStart(&I2C_DRIVER, &i2cconfig);
    msg_t status = i2cMasterTransmitTimeout(&I2C_DRIVER, (i2c_address >> 1), data, length, 0, 0, TIME_MS2I(timeout));
    return chibios_to_qmk(&status);
}

i2c_status_t i2c_receive(uint8_t address, uint8_t *data, uint16_t length, uint16_t timeout)
{
    i2c_address = address;
    i2cStart(&I2C_DRIVER, &i2cconfig);
    msg_t status = i2cMasterReceiveTimeout(&I2C_DRIVER, (i2c_address >> 1), data, length, TIME_MS2I(timeout));
    return chibios_to_qmk(&status);
}

i2c_status_t i2c_writeReg(uint8_t devaddr, uint8_t regaddr, const uint8_t *data, uint16_t length, uint16_t timeout)
{
    i2c_address = devaddr;
    i2cStart(&I2C_DRIVER, &i2cconfig);

    uint8_t complete_packet[length + 1];
    for (uint8_t i = 0; i < length; i++) {
        complete_packet[i + 1] = data[i];
    }
    complete_packet[0] = regaddr;

    msg_t status = i2cMasterTransmitTimeout(&I2C_DRIVER, (i2c_address >> 1), complete_packet, length + 1, 0, 0, TIME_MS2I(timeout));
    return chibios_to_qmk(&status);
}

i2c_status_t i2c_readReg(uint8_t devaddr, uint8_t *regaddr, uint8_t *data, uint16_t length, uint16_t timeout)
{
    i2c_address = devaddr;
    i2cStart(&I2C_DRIVER, &i2cconfig);
    msg_t status = i2cMasterTransmitTimeout(&I2C_DRIVER, (i2c_address >> 1), regaddr, 1, data, length, TIME_MS2I(timeout));
    return chibios_to_qmk(&status);
}

void i2c_stop(void)
{
    i2cStop(&I2C_DRIVER);
}