Both nRF I2C drivers (i2c_nrfx_twi and i2c_nrfx_twim) perform the bus recovery procedure in reaction to timeout (500 ms) of any requested message transfer. Add implementation of the I2C API recovery function in both these drivers so that it is also possible to execute this procedure directly. Signed-off-by: Andrzej Głąbek <andrzej.glabek@nordicsemi.no>
303 lines
8.2 KiB
C
303 lines
8.2 KiB
C
/*
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* Copyright (c) 2018, Nordic Semiconductor ASA
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#include <drivers/i2c.h>
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#include <dt-bindings/i2c/i2c.h>
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#include <nrfx_twi.h>
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#include <logging/log.h>
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LOG_MODULE_REGISTER(i2c_nrfx_twi, CONFIG_I2C_LOG_LEVEL);
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#define I2C_TRANSFER_TIMEOUT_MSEC K_MSEC(500)
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struct i2c_nrfx_twi_data {
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struct k_sem transfer_sync;
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struct k_sem completion_sync;
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volatile nrfx_err_t res;
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uint32_t dev_config;
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};
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struct i2c_nrfx_twi_config {
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nrfx_twi_t twi;
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nrfx_twi_config_t config;
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};
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static inline struct i2c_nrfx_twi_data *get_dev_data(const struct device *dev)
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{
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return dev->data;
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}
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static inline
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const struct i2c_nrfx_twi_config *get_dev_config(const struct device *dev)
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{
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return dev->config;
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}
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static int i2c_nrfx_twi_transfer(const struct device *dev,
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struct i2c_msg *msgs,
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uint8_t num_msgs, uint16_t addr)
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{
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int ret = 0;
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k_sem_take(&(get_dev_data(dev)->transfer_sync), K_FOREVER);
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/* Dummy take on completion_sync sem to be sure that it is empty */
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k_sem_take(&(get_dev_data(dev)->completion_sync), K_NO_WAIT);
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nrfx_twi_enable(&get_dev_config(dev)->twi);
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for (size_t i = 0; i < num_msgs; i++) {
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if (I2C_MSG_ADDR_10_BITS & msgs[i].flags) {
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ret = -ENOTSUP;
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break;
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}
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nrfx_twi_xfer_desc_t cur_xfer = {
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.p_primary_buf = msgs[i].buf,
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.primary_length = msgs[i].len,
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.address = addr,
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.type = (msgs[i].flags & I2C_MSG_READ) ?
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NRFX_TWI_XFER_RX : NRFX_TWI_XFER_TX
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};
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uint32_t xfer_flags = 0;
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nrfx_err_t res;
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/* In case the STOP condition is not supposed to appear after
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* the current message, check what is requested further:
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*/
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if (!(msgs[i].flags & I2C_MSG_STOP)) {
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/* - if the transfer consists of more messages
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* and the I2C repeated START is not requested
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* to appear before the next message, suspend
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* the transfer after the current message,
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* so that it can be resumed with the next one,
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* resulting in the two messages merged into
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* a continuous transfer on the bus
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*/
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if ((i < (num_msgs - 1)) &&
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!(msgs[i + 1].flags & I2C_MSG_RESTART)) {
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xfer_flags |= NRFX_TWI_FLAG_SUSPEND;
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/* - otherwise, just finish the transfer without
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* generating the STOP condition, unless the current
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* message is an RX request, for which such feature
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* is not supported
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*/
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} else if (msgs[i].flags & I2C_MSG_READ) {
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ret = -ENOTSUP;
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break;
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} else {
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xfer_flags |= NRFX_TWI_FLAG_TX_NO_STOP;
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}
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}
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res = nrfx_twi_xfer(&get_dev_config(dev)->twi,
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&cur_xfer,
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xfer_flags);
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if (res != NRFX_SUCCESS) {
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if (res == NRFX_ERROR_BUSY) {
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ret = -EBUSY;
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break;
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} else {
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ret = -EIO;
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break;
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}
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}
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ret = k_sem_take(&(get_dev_data(dev)->completion_sync),
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I2C_TRANSFER_TIMEOUT_MSEC);
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if (ret != 0) {
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/* Whatever the frequency, completion_sync should have
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* been given by the event handler.
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*
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* If it hasn't, it's probably due to an hardware issue
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* on the I2C line, for example a short between SDA and
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* GND.
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* This is issue has also been when trying to use the
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* I2C bus during MCU internal flash erase.
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*
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* In many situation, a retry is sufficient.
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* However, some time the I2C device get stuck and need
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* help to recover.
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* Therefore we always call nrfx_twi_bus_recover() to
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* make sure everything has been done to restore the
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* bus from this error.
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*/
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LOG_ERR("Error on I2C line occurred for message %d", i);
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nrfx_twi_disable(&get_dev_config(dev)->twi);
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nrfx_twi_bus_recover(get_dev_config(dev)->config.scl,
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get_dev_config(dev)->config.sda);
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ret = -EIO;
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break;
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}
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res = get_dev_data(dev)->res;
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if (res != NRFX_SUCCESS) {
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LOG_ERR("Error 0x%08X occurred for message %d", res, i);
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ret = -EIO;
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break;
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}
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}
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nrfx_twi_disable(&get_dev_config(dev)->twi);
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k_sem_give(&(get_dev_data(dev)->transfer_sync));
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return ret;
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}
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static void event_handler(nrfx_twi_evt_t const *p_event, void *p_context)
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{
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struct i2c_nrfx_twi_data *dev_data = p_context;
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switch (p_event->type) {
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case NRFX_TWI_EVT_DONE:
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dev_data->res = NRFX_SUCCESS;
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break;
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case NRFX_TWI_EVT_ADDRESS_NACK:
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dev_data->res = NRFX_ERROR_DRV_TWI_ERR_ANACK;
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break;
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case NRFX_TWI_EVT_DATA_NACK:
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dev_data->res = NRFX_ERROR_DRV_TWI_ERR_DNACK;
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break;
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default:
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dev_data->res = NRFX_ERROR_INTERNAL;
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break;
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}
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k_sem_give(&dev_data->completion_sync);
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}
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static int i2c_nrfx_twi_configure(const struct device *dev,
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uint32_t dev_config)
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{
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nrfx_twi_t const *inst = &(get_dev_config(dev)->twi);
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if (I2C_ADDR_10_BITS & dev_config) {
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return -EINVAL;
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}
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switch (I2C_SPEED_GET(dev_config)) {
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case I2C_SPEED_STANDARD:
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nrf_twi_frequency_set(inst->p_twi, NRF_TWI_FREQ_100K);
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break;
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case I2C_SPEED_FAST:
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nrf_twi_frequency_set(inst->p_twi, NRF_TWI_FREQ_400K);
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break;
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default:
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LOG_ERR("unsupported speed");
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return -EINVAL;
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}
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get_dev_data(dev)->dev_config = dev_config;
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return 0;
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}
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static int i2c_nrfx_twi_recover_bus(const struct device *dev)
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{
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nrfx_err_t err = nrfx_twi_bus_recover(get_dev_config(dev)->config.scl,
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get_dev_config(dev)->config.sda);
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return (err == NRFX_SUCCESS ? 0 : -EBUSY);
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}
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static const struct i2c_driver_api i2c_nrfx_twi_driver_api = {
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.configure = i2c_nrfx_twi_configure,
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.transfer = i2c_nrfx_twi_transfer,
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.recover_bus = i2c_nrfx_twi_recover_bus,
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};
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static int init_twi(const struct device *dev)
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{
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struct i2c_nrfx_twi_data *dev_data = get_dev_data(dev);
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nrfx_err_t result = nrfx_twi_init(&get_dev_config(dev)->twi,
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&get_dev_config(dev)->config,
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event_handler, dev_data);
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if (result != NRFX_SUCCESS) {
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LOG_ERR("Failed to initialize device: %s",
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dev->name);
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return -EBUSY;
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}
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return 0;
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}
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#ifdef CONFIG_PM_DEVICE
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static int twi_nrfx_pm_control(const struct device *dev,
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enum pm_device_action action)
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{
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int ret = 0;
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switch (action) {
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case PM_DEVICE_ACTION_RESUME:
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init_twi(dev);
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if (get_dev_data(dev)->dev_config) {
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i2c_nrfx_twi_configure(dev,
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get_dev_data(dev)->dev_config);
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}
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break;
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case PM_DEVICE_ACTION_SUSPEND:
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nrfx_twi_uninit(&get_dev_config(dev)->twi);
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break;
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default:
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ret = -ENOTSUP;
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}
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return ret;
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}
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#endif /* CONFIG_PM_DEVICE */
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#define I2C_NRFX_TWI_INVALID_FREQUENCY ((nrf_twi_frequency_t)-1)
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#define I2C_NRFX_TWI_FREQUENCY(bitrate) \
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(bitrate == I2C_BITRATE_STANDARD ? NRF_TWI_FREQ_100K \
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: bitrate == 250000 ? NRF_TWI_FREQ_250K \
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: bitrate == I2C_BITRATE_FAST ? NRF_TWI_FREQ_400K \
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: I2C_NRFX_TWI_INVALID_FREQUENCY)
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#define I2C(idx) DT_NODELABEL(i2c##idx)
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#define I2C_FREQUENCY(idx) \
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I2C_NRFX_TWI_FREQUENCY(DT_PROP(I2C(idx), clock_frequency))
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#define I2C_NRFX_TWI_DEVICE(idx) \
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BUILD_ASSERT(I2C_FREQUENCY(idx) != \
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I2C_NRFX_TWI_INVALID_FREQUENCY, \
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"Wrong I2C " #idx " frequency setting in dts"); \
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static int twi_##idx##_init(const struct device *dev) \
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{ \
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IRQ_CONNECT(DT_IRQN(I2C(idx)), DT_IRQ(I2C(idx), priority), \
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nrfx_isr, nrfx_twi_##idx##_irq_handler, 0); \
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return init_twi(dev); \
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} \
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static struct i2c_nrfx_twi_data twi_##idx##_data = { \
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.transfer_sync = Z_SEM_INITIALIZER( \
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twi_##idx##_data.transfer_sync, 1, 1), \
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.completion_sync = Z_SEM_INITIALIZER( \
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twi_##idx##_data.completion_sync, 0, 1) \
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}; \
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static const struct i2c_nrfx_twi_config twi_##idx##z_config = { \
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.twi = NRFX_TWI_INSTANCE(idx), \
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.config = { \
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.scl = DT_PROP(I2C(idx), scl_pin), \
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.sda = DT_PROP(I2C(idx), sda_pin), \
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.frequency = I2C_FREQUENCY(idx), \
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} \
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}; \
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DEVICE_DT_DEFINE(I2C(idx), \
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twi_##idx##_init, \
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twi_nrfx_pm_control, \
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&twi_##idx##_data, \
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&twi_##idx##z_config, \
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POST_KERNEL, \
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CONFIG_I2C_INIT_PRIORITY, \
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&i2c_nrfx_twi_driver_api)
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#ifdef CONFIG_I2C_0_NRF_TWI
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I2C_NRFX_TWI_DEVICE(0);
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#endif
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#ifdef CONFIG_I2C_1_NRF_TWI
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I2C_NRFX_TWI_DEVICE(1);
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#endif
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