zephyr/subsys/console/getchar.c

57 lines
1.2 KiB
C

/*
* Copyright (c) 2017 Linaro Limited.
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <zephyr.h>
#include <uart.h>
#include <misc/printk.h>
#include <drivers/console/console.h>
#include <drivers/console/uart_console.h>
#if CONFIG_CONSOLE_GETCHAR_BUFSIZE & (CONFIG_CONSOLE_GETCHAR_BUFSIZE - 1) != 0
#error CONFIG_CONSOLE_GETCHAR_BUFSIZE must be power of 2
#endif
static K_SEM_DEFINE(uart_sem, 0, UINT_MAX);
static u8_t uart_ringbuf[CONFIG_CONSOLE_GETCHAR_BUFSIZE];
static u8_t i_get, i_put;
static int console_irq_input_hook(u8_t c)
{
int i_next = (i_put + 1) & (CONFIG_CONSOLE_GETCHAR_BUFSIZE - 1);
if (i_next == i_get) {
printk("Console buffer overflow - char dropped\n");
return 1;
}
uart_ringbuf[i_put] = c;
i_put = i_next;
k_sem_give(&uart_sem);
return 1;
}
u8_t console_getchar(void)
{
unsigned int key;
u8_t c;
k_sem_take(&uart_sem, K_FOREVER);
key = irq_lock();
c = uart_ringbuf[i_get++];
i_get &= CONFIG_CONSOLE_GETCHAR_BUFSIZE - 1;
irq_unlock(key);
return c;
}
void console_getchar_init(void)
{
uart_console_in_debug_hook_install(console_irq_input_hook);
/* All NULLs because we're interested only in the callback above. */
uart_register_input(NULL, NULL, NULL);
}