circuitpython/ports/nrf/common-hal/busio/I2C.c

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/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2016 Sandeep Mistry All right reserved.
* Copyright (c) 2017 hathach
* Copyright (c) 2018 Artur Pacholec
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "shared-bindings/busio/I2C.h"
#include "py/mperrno.h"
#include "py/runtime.h"
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#include "supervisor/shared/translate.h"
#include "nrfx_twim.h"
#include "nrf_gpio.h"
#define INST_NO 0
#define MAX_XFER_SIZE ((1U << NRFX_CONCAT_3(TWIM, INST_NO, _EASYDMA_MAXCNT_SIZE)) - 1)
static uint8_t twi_error_to_mp(const nrfx_err_t err) {
switch (err) {
case NRFX_ERROR_DRV_TWI_ERR_ANACK:
return MP_ENODEV;
case NRFX_ERROR_BUSY:
return MP_EBUSY;
case NRFX_ERROR_DRV_TWI_ERR_DNACK:
case NRFX_ERROR_INVALID_ADDR:
return MP_EIO;
default:
break;
}
return 0;
}
void common_hal_busio_i2c_construct(busio_i2c_obj_t *self, const mcu_pin_obj_t *scl, const mcu_pin_obj_t *sda, uint32_t frequency, uint32_t timeout) {
if (scl->number == sda->number)
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mp_raise_ValueError(translate("Invalid pins"));
const nrfx_twim_t instance = NRFX_TWIM_INSTANCE(INST_NO);
self->twim = instance;
nrfx_twim_config_t config = NRFX_TWIM_DEFAULT_CONFIG;
config.scl = scl->number;
config.sda = sda->number;
// change freq. only if it's less than the default 400K
if (frequency < 100000) {
config.frequency = NRF_TWIM_FREQ_100K;
} else if (frequency < 250000) {
config.frequency = NRF_TWIM_FREQ_250K;
}
nrfx_err_t err = nrfx_twim_init(&self->twim, &config, NULL, NULL);
// A soft reset doesn't uninit the driver so we might end up with a invalid state
if (err == NRFX_ERROR_INVALID_STATE) {
nrfx_twim_uninit(&self->twim);
err = nrfx_twim_init(&self->twim, &config, NULL, NULL);
}
if (err != NRFX_SUCCESS)
mp_raise_OSError(MP_EIO);
self->inited = true;
}
bool common_hal_busio_i2c_deinited(busio_i2c_obj_t *self) {
return !self->inited;
}
void common_hal_busio_i2c_deinit(busio_i2c_obj_t *self) {
if (common_hal_busio_i2c_deinited(self))
return;
nrfx_twim_uninit(&self->twim);
self->inited = false;
}
// nrfx_twim_tx doesn't support 0-length data so we fall back to the hal API
bool common_hal_busio_i2c_probe(busio_i2c_obj_t *self, uint8_t addr) {
NRF_TWIM_Type *reg = self->twim.p_twim;
bool found = true;
nrfx_twim_enable(&self->twim);
nrf_twim_address_set(reg, addr);
nrf_twim_tx_buffer_set(reg, NULL, 0);
nrf_twim_task_trigger(reg, NRF_TWIM_TASK_RESUME);
nrf_twim_task_trigger(reg, NRF_TWIM_TASK_STARTTX);
while (nrf_twim_event_check(reg, NRF_TWIM_EVENT_TXSTARTED) == 0 &&
nrf_twim_event_check(reg, NRF_TWIM_EVENT_ERROR) == 0);
nrf_twim_event_clear(reg, NRF_TWIM_EVENT_TXSTARTED);
nrf_twim_task_trigger(reg, NRF_TWIM_TASK_STOP);
while (nrf_twim_event_check(reg, NRF_TWIM_EVENT_STOPPED) == 0);
nrf_twim_event_clear(reg, NRF_TWIM_EVENT_STOPPED);
if (nrf_twim_event_check(reg, NRF_TWIM_EVENT_ERROR)) {
nrf_twim_event_clear(reg, NRF_TWIM_EVENT_ERROR);
nrf_twim_errorsrc_get_and_clear(reg);
found = false;
}
nrfx_twim_disable(&self->twim);
return found;
}
bool common_hal_busio_i2c_try_lock(busio_i2c_obj_t *self) {
bool grabbed_lock = false;
// CRITICAL_SECTION_ENTER()
if (!self->has_lock) {
grabbed_lock = true;
self->has_lock = true;
}
// CRITICAL_SECTION_LEAVE();
return grabbed_lock;
}
bool common_hal_busio_i2c_has_lock(busio_i2c_obj_t *self) {
return self->has_lock;
}
void common_hal_busio_i2c_unlock(busio_i2c_obj_t *self) {
self->has_lock = false;
}
uint8_t common_hal_busio_i2c_write(busio_i2c_obj_t *self, uint16_t addr, const uint8_t *data, size_t len, bool stopBit) {
if(len == 0)
return common_hal_busio_i2c_probe(self, addr) ? 0 : MP_ENODEV;
const uint32_t parts = len / MAX_XFER_SIZE;
const uint32_t remainder = len % MAX_XFER_SIZE;
nrfx_err_t err = NRFX_SUCCESS;
nrfx_twim_enable(&self->twim);
for (uint32_t i = 0; i < parts; ++i) {
err = nrfx_twim_tx(&self->twim, addr, data + i * MAX_XFER_SIZE, MAX_XFER_SIZE, !stopBit);
if (err != NRFX_SUCCESS)
break;
}
if ((remainder > 0) && (err == NRFX_SUCCESS))
err = nrfx_twim_tx(&self->twim, addr, data + parts * MAX_XFER_SIZE, remainder, !stopBit);
nrfx_twim_disable(&self->twim);
return twi_error_to_mp(err);
}
uint8_t common_hal_busio_i2c_read(busio_i2c_obj_t *self, uint16_t addr, uint8_t *data, size_t len) {
if(len == 0)
return 0;
const uint32_t parts = len / MAX_XFER_SIZE;
const uint32_t remainder = len % MAX_XFER_SIZE;
nrfx_err_t err = NRFX_SUCCESS;
nrfx_twim_enable(&self->twim);
for (uint32_t i = 0; i < parts; ++i) {
err = nrfx_twim_rx(&self->twim, addr, data + i * MAX_XFER_SIZE, MAX_XFER_SIZE);
if (err != NRFX_SUCCESS)
break;
}
if ((remainder > 0) && (err == NRFX_SUCCESS))
err = nrfx_twim_rx(&self->twim, addr, data + parts * MAX_XFER_SIZE, remainder);
nrfx_twim_disable(&self->twim);
return twi_error_to_mp(err);
}