bm_lpuarte.h

/*
 * Copyright (c) 2025 Nordic Semiconductor ASA
 *
 * SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
 */
 
#ifndef LPUARTE_H__
#define LPUARTE_H__
 
#include <stdint.h>
#include <zephyr/sys/util.h>
#include <nrfx_gpiote.h>
#include <nrfx_uarte.h>
#include <bm/bm_timer.h>
 
#ifdef __cplusplus
extern "C" {
#endif
 
/* States. */
enum bm_lpuarte_rx_state {
        /* RX is disabled. */
        RX_OFF,
        /* RX is in low power, idle state with pin detection armed. */
        RX_IDLE,
        /* RX request is pending, receiver is in preparation. */
        RX_PREPARE,
        /* RX is in active state, receiver is running. */
        RX_ACTIVE,
        /* RX is transitioning to from active idle state. */
        RX_TO_IDLE,
        /* RX is transitioning to off state. */
        RX_TO_OFF,
};
 
/* Low power uart structure. */
struct bm_lpuarte {
        /* Physical UART device instance */
        nrfx_uarte_t *uarte_inst;
        /* Request pin. */
        nrfx_gpiote_pin_t req_pin;
        /* Response pin. */
        nrfx_gpiote_pin_t rdy_pin;
        /* GPIOTE channel used by rdy pin. */
        uint8_t rdy_ch;
        /* Timer used for TX timeout. */
        struct bm_timer tx_timer;
        /* Current TX buffer. */
        const uint8_t *tx_buf;
        /* Length of TX data. */
        size_t tx_len;
        /* Set to true if physical transfer is started. */
        bool tx_active;
        /* Application callback. */
        nrfx_uarte_event_handler_t callback;
        /* RX state */
        enum bm_lpuarte_rx_state rx_state;
};
 
/* Configuration structured. */
struct bm_lpuarte_config {
        /* Uarte instance. */
        nrfx_uarte_t *uarte_inst;
        /* Uarte instance configuration. */
        nrfx_uarte_config_t uarte_cfg;
        /* Request pin number. */
        nrfx_gpiote_pin_t req_pin;
        /* Ready pin number. */
        nrfx_gpiote_pin_t rdy_pin;
};
 
int bm_lpuarte_init(struct bm_lpuarte *lpu, struct bm_lpuarte_config *lpu_cfg,
                    nrfx_uarte_event_handler_t  event_handler);
 
void bm_lpuarte_uninit(struct bm_lpuarte *lpu);
 
int bm_lpuarte_tx(struct bm_lpuarte *lpu, const uint8_t *data, size_t length, int32_t timeout);
 
bool bm_lpuarte_tx_in_progress(struct bm_lpuarte *lpu);
 
int bm_lpuarte_tx_abort(struct bm_lpuarte *lpu, bool sync);
 
int bm_lpuarte_rx_enable(struct bm_lpuarte *lpu);
 
int bm_lpuarte_rx_buffer_set(struct bm_lpuarte *lpu, uint8_t *data, size_t length);
 
int bm_lpuarte_rx_abort(struct bm_lpuarte *lpu, bool sync);
 
#ifdef __cplusplus
}
#endif
 
#endif /* LPUARTE_H__ */