blob: b0654bdbf790775c67ef7050896eae186fa70ec8 [file] [log] [blame]
/*
* Copyright (c) 2018 Linaro Limited.
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <zephyr.h>
#include <drivers/uart.h>
#include <sys/printk.h>
#include <console/tty.h>
static int tty_irq_input_hook(struct tty_serial *tty, u8_t c);
static int tty_putchar(struct tty_serial *tty, u8_t c);
static void tty_uart_isr(void *user_data)
{
struct tty_serial *tty = user_data;
struct device *dev = tty->uart_dev;
uart_irq_update(dev);
if (uart_irq_rx_ready(dev)) {
u8_t c;
while (1) {
if (uart_fifo_read(dev, &c, 1) == 0) {
break;
}
tty_irq_input_hook(tty, c);
}
}
if (uart_irq_tx_ready(dev)) {
if (tty->tx_get == tty->tx_put) {
/* Output buffer empty, don't bother
* us with tx interrupts
*/
uart_irq_tx_disable(dev);
} else {
uart_fifo_fill(dev, &tty->tx_ringbuf[tty->tx_get++], 1);
if (tty->tx_get >= tty->tx_ringbuf_sz) {
tty->tx_get = 0U;
}
k_sem_give(&tty->tx_sem);
}
}
}
static int tty_irq_input_hook(struct tty_serial *tty, u8_t c)
{
int rx_next = tty->rx_put + 1;
if (rx_next >= tty->rx_ringbuf_sz) {
rx_next = 0;
}
if (rx_next == tty->rx_get) {
/* Try to give a clue to user that some input was lost */
tty_putchar(tty, '~');
return 1;
}
tty->rx_ringbuf[tty->rx_put] = c;
tty->rx_put = rx_next;
k_sem_give(&tty->rx_sem);
return 1;
}
static int tty_putchar(struct tty_serial *tty, u8_t c)
{
unsigned int key;
int tx_next;
int res;
res = k_sem_take(&tty->tx_sem, tty->tx_timeout);
if (res < 0) {
return res;
}
key = irq_lock();
tx_next = tty->tx_put + 1;
if (tx_next >= tty->tx_ringbuf_sz) {
tx_next = 0;
}
if (tx_next == tty->tx_get) {
irq_unlock(key);
return -ENOSPC;
}
tty->tx_ringbuf[tty->tx_put] = c;
tty->tx_put = tx_next;
irq_unlock(key);
uart_irq_tx_enable(tty->uart_dev);
return 0;
}
ssize_t tty_write(struct tty_serial *tty, const void *buf, size_t size)
{
const u8_t *p = buf;
size_t out_size = 0;
int res = 0;
if (tty->tx_ringbuf_sz == 0U) {
/* Unbuffered operation, implicitly blocking. */
out_size = size;
while (size--) {
uart_poll_out(tty->uart_dev, *p++);
}
return out_size;
}
while (size--) {
res = tty_putchar(tty, *p++);
if (res < 0) {
/* If we didn't transmit anything, return the error. */
if (out_size == 0) {
errno = -res;
return res;
}
/*
* Otherwise, return how much we transmitted. If error
* was transient (like EAGAIN), on next call user might
* not even get it. And if it's non-transient, they'll
* get it on the next call.
*/
return out_size;
}
out_size++;
}
return out_size;
}
static int tty_getchar(struct tty_serial *tty)
{
unsigned int key;
u8_t c;
int res;
res = k_sem_take(&tty->rx_sem, tty->rx_timeout);
if (res < 0) {
return res;
}
key = irq_lock();
c = tty->rx_ringbuf[tty->rx_get++];
if (tty->rx_get >= tty->rx_ringbuf_sz) {
tty->rx_get = 0U;
}
irq_unlock(key);
return c;
}
static ssize_t tty_read_unbuf(struct tty_serial *tty, void *buf, size_t size)
{
u8_t *p = buf;
size_t out_size = 0;
int res = 0;
u32_t timeout = tty->rx_timeout;
while (size) {
u8_t c;
res = uart_poll_in(tty->uart_dev, &c);
if (res <= -2) {
/* Error occurred, best we can do is to return
* accumulated data w/o error, or return error
* directly if none.
*/
if (out_size == 0) {
errno = res;
return -1;
}
break;
}
if (res == 0) {
*p++ = c;
out_size++;
size--;
}
if (size == 0 || (timeout != K_FOREVER && timeout-- == 0U)) {
break;
}
/* Avoid 100% busy-polling, and yet try to process bursts
* of data without extra delays.
*/
if (res == -1) {
k_sleep(K_MSEC(1));
}
}
return out_size;
}
ssize_t tty_read(struct tty_serial *tty, void *buf, size_t size)
{
u8_t *p = buf;
size_t out_size = 0;
int res = 0;
if (tty->rx_ringbuf_sz == 0U) {
return tty_read_unbuf(tty, buf, size);
}
while (size--) {
res = tty_getchar(tty);
if (res < 0) {
/* If we didn't transmit anything, return the error. */
if (out_size == 0) {
errno = -res;
return res;
}
/*
* Otherwise, return how much we transmitted. If error
* was transient (like EAGAIN), on next call user might
* not even get it. And if it's non-transient, they'll
* get it on the next call.
*/
return out_size;
}
*p++ = (u8_t)res;
out_size++;
}
return out_size;
}
int tty_init(struct tty_serial *tty, struct device *uart_dev)
{
if (!uart_dev) {
return -ENODEV;
}
tty->uart_dev = uart_dev;
/* We start in unbuffer mode. */
tty->rx_ringbuf = NULL;
tty->rx_ringbuf_sz = 0U;
tty->tx_ringbuf = NULL;
tty->tx_ringbuf_sz = 0U;
tty->rx_get = tty->rx_put = tty->tx_get = tty->tx_put = 0U;
tty->rx_timeout = K_FOREVER;
tty->tx_timeout = K_FOREVER;
uart_irq_callback_user_data_set(uart_dev, tty_uart_isr, tty);
return 0;
}
int tty_set_rx_buf(struct tty_serial *tty, void *buf, size_t size)
{
uart_irq_rx_disable(tty->uart_dev);
tty->rx_ringbuf = buf;
tty->rx_ringbuf_sz = size;
if (size > 0) {
k_sem_init(&tty->rx_sem, 0, UINT_MAX);
uart_irq_rx_enable(tty->uart_dev);
}
return 0;
}
int tty_set_tx_buf(struct tty_serial *tty, void *buf, size_t size)
{
uart_irq_tx_disable(tty->uart_dev);
tty->tx_ringbuf = buf;
tty->tx_ringbuf_sz = size;
k_sem_init(&tty->tx_sem, size - 1, UINT_MAX);
/* New buffer is initially empty, no need to re-enable interrupts,
* it will be done when needed (on first output char).
*/
return 0;
}