zephyr/drivers/serial/uart_ql_usbserialport_s3b.c

86 lines
2.0 KiB
C

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