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>

include/console.h

@@ -14,6 +14,56 @@
 extern "C" {
 #endif
 
+struct tty_serial {
+	struct device *uart_dev;
+
+	struct k_sem rx_sem;
+	u8_t *rx_ringbuf;
+	u32_t rx_ringbuf_sz;
+	u16_t rx_get, rx_put;
+
+	u8_t *tx_ringbuf;
+	u32_t tx_ringbuf_sz;
+	u16_t tx_get, tx_put;
+};
+
+/**
+ * @brief Initialize buffered serial port (classically known as tty).
+ *
+ * "tty" device provides buffered, interrupt-driver access to an
+ * underlying UART device.
+ *
+ * @param tty tty device structure to initialize
+ * @param uart_dev underlying UART device to use (should support
+ *                 interrupt-driven operation)
+ * @param rxbuf pointer to receive buffer
+ * @param rxbuf_sz size of receive buffer
+ * @param txbuf pointer to transmit buffer
+ * @param txbuf_sz size of transmit buffer
+ *
+ * @return N/A
+ */
+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);
+
+
+/**
+ * @brief Input a character from a tty device.
+ *
+ * @param tty tty device structure
+ */
+u8_t tty_getchar(struct tty_serial *tty);
+
+/**
+ * @brief Output a character from to tty device.
+ *
+ * @param tty tty device structure
+ * @param c character to output
+ * @return 0 if ok, <0 if error
+ */
+int tty_putchar(struct tty_serial *tty, u8_t c);
+
 /** @brief Initialize console_getchar()/putchar() calls.
  *
  *  This function should be called once to initialize pull-style

subsys/console/CMakeLists.txt

@@ -1,3 +1,3 @@
 zephyr_sources(line_fifo.c)
-zephyr_sources_ifdef(CONFIG_CONSOLE_GETCHAR getchar.c)
+zephyr_sources_ifdef(CONFIG_CONSOLE_GETCHAR tty.c getchar.c)
 zephyr_sources_ifdef(CONFIG_CONSOLE_GETLINE getline.c)

subsys/console/getchar.c

@@ -5,146 +5,17 @@
  */
 
 #include <zephyr.h>
-#include <uart.h>
+#include <device.h>
-#include <misc/printk.h>
 #include <console.h>
-#include <drivers/console/console.h>
-#include <drivers/console/uart_console.h>
 
-struct tty_serial {
+static struct tty_serial console_serial;
-	struct device *uart_dev;
-
-	struct k_sem rx_sem;
-	u8_t *rx_ringbuf;
-	u32_t rx_ringbuf_sz;
-	u16_t rx_get, rx_put;
-
-	u8_t *tx_ringbuf;
-	u32_t tx_ringbuf_sz;
-	u16_t tx_get, tx_put;
-};
 
 static u8_t console_rxbuf[CONFIG_CONSOLE_GETCHAR_BUFSIZE];
 static u8_t console_txbuf[CONFIG_CONSOLE_PUTCHAR_BUFSIZE];
 
-static int tty_irq_input_hook(struct tty_serial *tty, u8_t c);
-
-static struct tty_serial console_serial;
-
-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, char 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] = (u8_t)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);
-}
-
-
 int console_putchar(char c)
 {
-	return tty_putchar(&console_serial, c);
+	return tty_putchar(&console_serial, (u8_t)c);
 }
 
 u8_t console_getchar(void)

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);
+}