87 lines
2.0 KiB
C
87 lines
2.0 KiB
C
/*
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* Copyright (c) 2022 Antmicro <www.antmicro.com>
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#define DT_DRV_COMPAT quicklogic_usbserialport_s3b
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#include <zephyr/kernel.h>
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#include <zephyr/drivers/uart.h>
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#include <eoss3_dev.h>
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#include "uart_ql_usbserialport_s3b.h"
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/*
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* code is a modified version of usbserial driver from https://github.com/QuickLogic-Corp/qorc-sdk
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* freertos_gateware/src/eoss3_hal_fpga_usbserial.c
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* freertos_gateware/inc/eoss3_hal_fpga_usbserial.h
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*/
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volatile struct fpga_usbserial_regs *usbserial_regs
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= (struct fpga_usbserial_regs *)(FPGA_PERIPH_BASE);
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static uint32_t usbserial_tx_fifo_status(void)
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{
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return usbserial_regs->m2u_fifo_flags;
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}
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static bool usbserial_tx_fifo_full(void)
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{
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return usbserial_tx_fifo_status() == USBSERIAL_TX_FIFO_FULL;
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}
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static uint32_t usbserial_rx_fifo_status(void)
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{
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return usbserial_regs->u2m_fifo_flags;
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}
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static bool usbserial_rx_fifo_empty(void)
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{
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return usbserial_rx_fifo_status() == USBSERIAL_RX_FIFO_EMPTY;
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}
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/**
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* @brief Output a character in polled mode.
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*
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* Writes data to tx register. Waits for space if transmitter is full.
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*
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* @param dev UART device struct
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* @param c Character to send
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*/
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static void uart_usbserial_poll_out(const struct device *dev, unsigned char c)
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{
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/* Wait for room in Tx FIFO */
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while (usbserial_tx_fifo_full()) {
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;
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}
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usbserial_regs->wdata = c;
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}
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/**
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* @brief Poll the device for input.
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*
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* @param dev UART device struct
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* @param c Pointer to character
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*
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* @return 0 if a character arrived, -1 if the input buffer if empty.
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*/
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static int uart_usbserial_poll_in(const struct device *dev, unsigned char *c)
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{
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if (usbserial_rx_fifo_empty()) {
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return -1;
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}
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*c = usbserial_regs->rdata;
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return 0;
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}
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static const struct uart_driver_api uart_usbserial_driver_api = {
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.poll_in = uart_usbserial_poll_in,
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.poll_out = uart_usbserial_poll_out,
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};
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DEVICE_DT_INST_DEFINE(0, NULL, NULL, NULL, NULL, PRE_KERNEL_1,
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CONFIG_SERIAL_INIT_PRIORITY,
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(void *)&uart_usbserial_driver_api);
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