304 lines
8.2 KiB
C
304 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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