uart.c

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/*
Copyright (c) 2023 Eindhoven University of Technology
 
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
 
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
 
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/
#include "uart.h"
#include "arm_shared_memory_system.h"
#include "log.h"
#include <platform.h>
#include <stdio.h>
 
static arm_shared uart0_handle, uart1_handle;
static volatile uint32_t *uart0 = NULL;
static volatile uint32_t *uart1 = NULL;
 
void uart_init(const int uart) {
  if (uart == UART0) {
    uart0 = arm_shared_init(&uart0_handle, axi_uartlite_0, 4096);
  } else if (uart == UART1) {
    uart1 = arm_shared_init(&uart1_handle, axi_uartlite_1, 4096);
  } else {
    pynq_error("uart_init: invalid UART %d, must be 0..%d\n", uart, NUM_UARTS);
  }
}
 
void uart_destroy(const int uart) {
  if (uart == UART0) {
    if (uart0 == NULL) {
      pynq_error("uart_destroy: shared memory has not been instantiated\n");
    }
    arm_shared_close(&uart0_handle);
  } else if (uart == UART1) {
    if (uart1 == NULL) {
      pynq_error("uart_destroy: shared memory has not been instantiated\n");
    }
    arm_shared_close(&uart1_handle);
  } else {
    pynq_error("uart_destroy: channel %d does not exist\n", uart);
  }
}
 
void uart_send(const int uart, const uint8_t data) {
  if (uart == UART0) {
    while ((uart0[2] & 8) == 8)
      ;
    uart0[1] = data;
  } else if (uart == UART1) {
    while ((uart1[2] & 8) == 8)
      ;
    uart1[1] = data;
  } else {
    pynq_error("uart_send: invalid UART %d, must be 0..%d\n", uart, NUM_UARTS);
  }
}
 
uint8_t uart_recv(const int uart) {
  if (uart == UART0) {
    while ((uart0[2] & 1) == 0) {
    }
    return uart0[0];
  } else if (uart == UART1) {
    while ((uart1[2] & 1) == 0) {
    }
    return uart1[0];
  } else {
    pynq_error("uart_recv: invalid UART %d, must be 0..%d\n", uart, NUM_UARTS);
  }
  return 0;
}
 
bool uart_has_data(const int uart) {
  if (uart == UART0) {
    return ((uart0[2] & 1) != 0);
  } else if (uart == UART1) {
    return ((uart1[2] & 1) != 0);
  } else {
    pynq_error("uart_has_data: invalid UART %d, must be 0..%d\n", uart,
               NUM_UARTS);
  }
  return false;
}
 
bool uart_has_space(const int uart) {
  if (uart == UART0) {
    return ((uart0[2] & 8) == 0);
  } else if (uart == UART1) {
    return ((uart1[2] & 8) == 0);
  } else {
    pynq_error("uart_has_space: invalid UART %d, must be 0..%d\n", uart,
               NUM_UARTS);
  }
  return false;
}
 
void uart_reset_fifos(const int uart) {
  if (uart == UART0) {
    uart0[3] = 3;
  } else if (uart == UART1) {
    uart1[3] = 3;
  } else {
    pynq_error("uart_reset_fifos: invalid UART %d, must be 0..%d\n", uart,
               NUM_UARTS);
  }
}