subsys: console: Split serial tty handling to a separate module
Before going further for API refactoring in console subsys, makes
sense to split "tty" implementation from "console" implementation,
to make it clearer that "console" is just a "tty" instantiated on
a particular UART device.
Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
diff --git a/subsys/console/tty.c b/subsys/console/tty.c
new file mode 100644
index 0000000..5f004f5
--- /dev/null
+++ b/subsys/console/tty.c
@@ -0,0 +1,125 @@
+/*
+ * Copyright (c) 2018 Linaro Limited.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr.h>
+#include <uart.h>
+#include <misc/printk.h>
+#include <console.h>
+#include <drivers/console/console.h>
+#include <drivers/console/uart_console.h>
+
+static int tty_irq_input_hook(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 = 0;
+ }
+ }
+ }
+}
+
+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 */
+ console_putchar('~');
+ console_putchar('\n');
+ return 1;
+ }
+
+ tty->rx_ringbuf[tty->rx_put] = c;
+ tty->rx_put = rx_next;
+ k_sem_give(&tty->rx_sem);
+
+ return 1;
+}
+
+int tty_putchar(struct tty_serial *tty, u8_t c)
+{
+ unsigned int key;
+ int tx_next;
+
+ 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 -1;
+ }
+
+ tty->tx_ringbuf[tty->tx_put] = c;
+ tty->tx_put = tx_next;
+
+ irq_unlock(key);
+ uart_irq_tx_enable(tty->uart_dev);
+ return 0;
+}
+
+u8_t tty_getchar(struct tty_serial *tty)
+{
+ unsigned int key;
+ u8_t c;
+
+ k_sem_take(&tty->rx_sem, K_FOREVER);
+
+ key = irq_lock();
+ c = tty->rx_ringbuf[tty->rx_get++];
+ if (tty->rx_get >= tty->rx_ringbuf_sz) {
+ tty->rx_get = 0;
+ }
+ irq_unlock(key);
+
+ return c;
+}
+
+void tty_init(struct tty_serial *tty, struct device *uart_dev,
+ u8_t *rxbuf, u16_t rxbuf_sz,
+ u8_t *txbuf, u16_t txbuf_sz)
+{
+ tty->uart_dev = uart_dev;
+ tty->rx_ringbuf = rxbuf;
+ tty->rx_ringbuf_sz = rxbuf_sz;
+ tty->tx_ringbuf = txbuf;
+ tty->tx_ringbuf_sz = txbuf_sz;
+ tty->rx_get = tty->rx_put = tty->tx_get = tty->tx_put = 0;
+ k_sem_init(&tty->rx_sem, 0, UINT_MAX);
+
+ uart_irq_callback_user_data_set(uart_dev, tty_uart_isr, tty);
+ uart_irq_rx_enable(uart_dev);
+}
