text: /*
   * Copyright (c) 2011-2012, 2014-2015 Wind River Systems, Inc.
   *
   * SPDX-License-Identifier: Apache-2.0
   */
  
  /**
   * @file
   * @brief UART-driven console
   *
   *
   * Serial console driver.
   * Hooks into the printk and fputc (for printf) modules. Poll driven.
   */
  
  #include <kernel.h>
  
  #include <stdio.h>
  #include <zephyr/types.h>
  #include <errno.h>
  #include <ctype.h>
  
  #include <device.h>
  #include <init.h>
  
  #include <drivers/uart.h>
  #include <drivers/console/console.h>
  #include <drivers/console/uart_console.h>
  #include <toolchain.h>
  #include <linker/sections.h>
  #include <sys/atomic.h>
  #include <sys/printk.h>
  #ifdef CONFIG_UART_CONSOLE_MCUMGR
  #include "mgmt/serial.h"
  #endif
  #ifdef CONFIG_USB_UART_CONSOLE
  #include <usb/usb_device.h>
  #endif
  
  static struct device *uart_console_dev;
  
  #ifdef CONFIG_UART_CONSOLE_DEBUG_SERVER_HOOKS
  
  static uart_console_in_debug_hook_t debug_hook_in;
  void uart_console_in_debug_hook_install(uart_console_in_debug_hook_t hook)
  {
  	debug_hook_in = hook;
  }
  
  static UART_CONSOLE_OUT_DEBUG_HOOK_SIG(debug_hook_out_nop) {
  	ARG_UNUSED(c);
  	return !UART_CONSOLE_DEBUG_HOOK_HANDLED;
  }
  
  static uart_console_out_debug_hook_t *debug_hook_out = debug_hook_out_nop;
  void uart_console_out_debug_hook_install(uart_console_out_debug_hook_t *hook)
  {
  	debug_hook_out = hook;
  }
  #define HANDLE_DEBUG_HOOK_OUT(c) \
  	(debug_hook_out(c) == UART_CONSOLE_DEBUG_HOOK_HANDLED)
  
  #endif /* CONFIG_UART_CONSOLE_DEBUG_SERVER_HOOKS */
  
  
  #if defined(CONFIG_PRINTK) || defined(CONFIG_STDOUT_CONSOLE)
  /**
   *
   * @brief Output one character to UART
   *
   * Outputs both line feed and carriage return in the case of a '\n'.
   *
   * @param c Character to output
   *
   * @return The character passed as input.
   */
  
  static int console_out(int c)
  {
  #ifdef CONFIG_UART_CONSOLE_DEBUG_SERVER_HOOKS
  
  	int handled_by_debug_server = HANDLE_DEBUG_HOOK_OUT(c);
  
  	if (handled_by_debug_server) {
  		return c;
  	}
  
  #endif  /* CONFIG_UART_CONSOLE_DEBUG_SERVER_HOOKS */
  
  	if ('\n' == c) {
  		uart_poll_out(uart_console_dev, '\r');
  	}
  	uart_poll_out(uart_console_dev, c);
  
  	return c;
  }
  
  #endif
  
  #if defined(CONFIG_STDOUT_CONSOLE)
  extern void __stdout_hook_install(int (*hook)(int));
  #else
  #define __stdout_hook_install(x) \
  	do {    /* nothing */	 \
  	} while ((0))
  #endif
  
  #if defined(CONFIG_PRINTK)
  extern void __printk_hook_install(int (*fn)(int));
  #else
  #define __printk_hook_install(x) \
  	do {    /* nothing */	 \
  	} while ((0))
  #endif
  
  #if defined(CONFIG_CONSOLE_HANDLER)
  static struct k_fifo *avail_queue;
  static struct k_fifo *lines_queue;
  static u8_t (*completion_cb)(char *line, u8_t len);
  
  /* Control characters */
  #define BS                 0x08
  #define ESC                0x1b
  #define DEL                0x7f
  
  /* ANSI escape sequences */
  #define ANSI_ESC           '['
  #define ANSI_UP            'A'
  #define ANSI_DOWN          'B'
  #define ANSI_FORWARD       'C'
  #define ANSI_BACKWARD      'D'
  #define ANSI_END           'F'
  #define ANSI_HOME          'H'
  #define ANSI_DEL           '~'
  
  static int read_uart(struct device *uart, u8_t *buf, unsigned int size)
  {
  	int rx;
  
  	rx = uart_fifo_read(uart, buf, size);
  	if (rx < 0) {
  		/* Overrun issue. Stop the UART */
  		uart_irq_rx_disable(uart);
  
  		return -EIO;
  	}
  
  	return rx;
  }
  
  static inline void cursor_forward(unsigned int count)
  {
  	printk("\x1b[%uC", count);
  }
  
  static inline void cursor_backward(unsigned int count)
  {
  	printk("\x1b[%uD", count);
  }
  
  static inline void cursor_save(void)
  {
  	printk("\x1b[s");
  }
  
  static inline void cursor_restore(void)
  {
  	printk("\x1b[u");
  }
  
  static void insert_char(char *pos, char c, u8_t end)
  {
  	char tmp;
  
  	/* Echo back to console */
  	uart_poll_out(uart_console_dev, c);
  
  	if (end == 0U) {
  		*pos = c;
  		return;
  	}
  
  	tmp = *pos;
  	*(pos++) = c;
  
  	cursor_save();
  
  	while (end-- > 0) {
  		uart_poll_out(uart_console_dev, tmp);
  		c = *pos;
  		*(pos++) = tmp;
  		tmp = c;
  	}
  
  	/* Move cursor back to right place */
  	cursor_restore();
  }
  
  static void del_char(char *pos, u8_t end)
  {
  	uart_poll_out(uart_console_dev, '\b');
  
  	if (end == 0U) {
  		uart_poll_out(uart_console_dev, ' ');
  		uart_poll_out(uart_console_dev, '\b');
  		return;
  	}
  
  	cursor_save();
  
  	while (end-- > 0) {
  		*pos = *(pos + 1);
  		uart_poll_out(uart_console_dev, *(pos++));
  	}
  
  	uart_poll_out(uart_console_dev, ' ');
  
  	/* Move cursor back to right place */
  	cursor_restore();
  }
  
  enum {
  	ESC_ESC,
  	ESC_ANSI,
  	ESC_ANSI_FIRST,
  	ESC_ANSI_VAL,
  	ESC_ANSI_VAL_2,
  #ifdef CONFIG_UART_CONSOLE_MCUMGR
  	ESC_MCUMGR_PKT_1,
  	ESC_MCUMGR_PKT_2,
  	ESC_MCUMGR_FRAG_1,
  	ESC_MCUMGR_FRAG_2,
  #endif
  };
  
  static atomic_t esc_state;
  static unsigned int ansi_val, ansi_val_2;
  static u8_t cur, end;
  
  static void handle_ansi(u8_t byte, char *line)
  {
  	if (atomic_test_and_clear_bit(&esc_state, ESC_ANSI_FIRST)) {
  		if (!isdigit(byte)) {
  			ansi_val = 1U;
  			goto ansi_cmd;
  		}
  
  		atomic_set_bit(&esc_state, ESC_ANSI_VAL);
  		ansi_val = byte - '0';
  		ansi_val_2 = 0U;
  		return;
  	}
  
  	if (atomic_test_bit(&esc_state, ESC_ANSI_VAL)) {
  		if (isdigit(byte)) {
  			if (atomic_test_bit(&esc_state, ESC_ANSI_VAL_2)) {
  				ansi_val_2 *= 10U;
  				ansi_val_2 += byte - '0';
  			} else {
  				ansi_val *= 10U;
  				ansi_val += byte - '0';
  			}
  			return;
  		}
  
  		/* Multi value sequence, e.g. Esc[Line;ColumnH */
  		if (byte == ';' &&
  		    !atomic_test_and_set_bit(&esc_state, ESC_ANSI_VAL_2)) {
  			return;
  		}
  
  		atomic_clear_bit(&esc_state, ESC_ANSI_VAL);
  		atomic_clear_bit(&esc_state, ESC_ANSI_VAL_2);
  	}
  
  ansi_cmd:
  	switch (byte) {
  	case ANSI_BACKWARD:
  		if (ansi_val > cur) {
  			break;
  		}
  
  		end += ansi_val;
  		cur -= ansi_val;
  		cursor_backward(ansi_val);
  		break;
  	case ANSI_FORWARD:
  		if (ansi_val > end) {
  			break;
  		}
  
  		end -= ansi_val;
  		cur += ansi_val;
  		cursor_forward(ansi_val);
  		break;
  	case ANSI_HOME:
  		if (!cur) {
  			break;
  		}
  
  		cursor_backward(cur);
  		end += cur;
  		cur = 0U;
  		break;
  	case ANSI_END:
  		if (!end) {
  			break;
  		}
  
  		cursor_forward(end);
  		cur += end;
  		end = 0U;
  		break;
  	case ANSI_DEL:
  		if (!end) {
  			break;
  		}
  
  		cursor_forward(1);
  		del_char(&line[cur], --end);
  		break;
  	default:
  		break;
  	}
  
  	atomic_clear_bit(&esc_state, ESC_ANSI);
  }
  
  #ifdef CONFIG_UART_CONSOLE_MCUMGR
  
  static void clear_mcumgr(void)
  {
  	atomic_clear_bit(&esc_state, ESC_MCUMGR_PKT_1);
  	atomic_clear_bit(&esc_state, ESC_MCUMGR_PKT_2);
  	atomic_clear_bit(&esc_state, ESC_MCUMGR_FRAG_1);
  	atomic_clear_bit(&esc_state, ESC_MCUMGR_FRAG_2);
  }
  
  /**
   * These states indicate whether an mcumgr frame is being received.
   */
  #define CONSOLE_MCUMGR_STATE_NONE       1
  #define CONSOLE_MCUMGR_STATE_HEADER     2
  #define CONSOLE_MCUMGR_STATE_PAYLOAD    3
  
  static int read_mcumgr_byte(uint8_t byte)
  {
  	bool frag_1;
  	bool frag_2;
  	bool pkt_1;
  	bool pkt_2;
  
  	pkt_1 = atomic_test_bit(&esc_state, ESC_MCUMGR_PKT_1);
  	pkt_2 = atomic_test_bit(&esc_state, ESC_MCUMGR_PKT_2);
  	frag_1 = atomic_test_bit(&esc_state, ESC_MCUMGR_FRAG_1);
  	frag_2 = atomic_test_bit(&esc_state, ESC_MCUMGR_FRAG_2);
  
  	if (pkt_2 || frag_2) {
  		/* Already fully framed. */
  		return CONSOLE_MCUMGR_STATE_PAYLOAD;
  	}
  
  	if (pkt_1) {
  		if (byte == MCUMGR_SERIAL_HDR_PKT_2) {
  			/* Final framing byte received. */
  			atomic_set_bit(&esc_state, ESC_MCUMGR_PKT_2);
  			return CONSOLE_MCUMGR_STATE_PAYLOAD;
  		}
  	} else if (frag_1) {
  		if (byte == MCUMGR_SERIAL_HDR_FRAG_2) {
  			/* Final framing byte received. */
  			atomic_set_bit(&esc_state, ESC_MCUMGR_FRAG_2);
  			return CONSOLE_MCUMGR_STATE_PAYLOAD;
  		}
  	} else {
  		if (byte == MCUMGR_SERIAL_HDR_PKT_1) {
  			/* First framing byte received. */
  			atomic_set_bit(&esc_state, ESC_MCUMGR_PKT_1);
  			return CONSOLE_MCUMGR_STATE_HEADER;
  		} else if (byte == MCUMGR_SERIAL_HDR_FRAG_1) {
  			/* First framing byte received. */
  			atomic_set_bit(&esc_state, ESC_MCUMGR_FRAG_1);
  			return CONSOLE_MCUMGR_STATE_HEADER;
  		}
  	}
  
  	/* Non-mcumgr byte received. */
  	return CONSOLE_MCUMGR_STATE_NONE;
  }
  
  /**
   * @brief Attempts to process a received byte as part of an mcumgr frame.
   *
   * @param cmd The console command currently being received.
   * @param byte The byte just received.
   *
   * @return true if the command being received is an mcumgr frame; false if it
   * is a plain console command.
   */
  static bool handle_mcumgr(struct console_input *cmd, uint8_t byte)
  {
  	int mcumgr_state;
  
  	mcumgr_state = read_mcumgr_byte(byte);
  	if (mcumgr_state == CONSOLE_MCUMGR_STATE_NONE) {
  		/* Not an mcumgr command; let the normal console handling
  		 * process the byte.
  		 */
  		cmd->is_mcumgr = 0;
  		return false;
  	}
  
  	/* The received byte is part of an mcumgr command.  Process the byte
  	 * and return true to indicate that normal console handling should
  	 * ignore it.
  	 */
  	if (cur + end < sizeof(cmd->line) - 1) {
  		cmd->line[cur++] = byte;
  	}
  	if (mcumgr_state == CONSOLE_MCUMGR_STATE_PAYLOAD && byte == '\n') {
  		cmd->line[cur + end] = '\0';
  		cmd->is_mcumgr = 1;
  		k_fifo_put(lines_queue, cmd);
  
  		clear_mcumgr();
  		cmd = NULL;
  		cur = 0U;
  		end = 0U;
  	}
  
  	return true;
  }
  
  #endif /* CONFIG_UART_CONSOLE_MCUMGR */
  
  void uart_console_isr(struct device *unused)
  {
  	ARG_UNUSED(unused);
  
  	while (uart_irq_update(uart_console_dev) &&
  	       uart_irq_is_pending(uart_console_dev)) {
  		static struct console_input *cmd;
  		u8_t byte;
  		int rx;
  
  		if (!uart_irq_rx_ready(uart_console_dev)) {
  			continue;
  		}
  
  		/* Character(s) have been received */
  
  		rx = read_uart(uart_console_dev, &byte, 1);
  		if (rx < 0) {
  			return;
  		}
  
  #ifdef CONFIG_UART_CONSOLE_DEBUG_SERVER_HOOKS
  		if (debug_hook_in != NULL && debug_hook_in(byte) != 0) {
  			/*
  			 * The input hook indicates that no further processing
  			 * should be done by this handler.
  			 */
  			return;
  		}
  #endif
  
  		if (!cmd) {
  			cmd = k_fifo_get(avail_queue, K_NO_WAIT);
  			if (!cmd) {
  				return;
  			}
  		}
  
  #ifdef CONFIG_UART_CONSOLE_MCUMGR
  		/* Divert this byte from normal console handling if it is part
  		 * of an mcumgr frame.
  		 */
  		if (handle_mcumgr(cmd, byte)) {
  			continue;
  		}
  #endif          /* CONFIG_UART_CONSOLE_MCUMGR */
  
  		/* Handle ANSI escape mode */
  		if (atomic_test_bit(&esc_state, ESC_ANSI)) {
  			handle_ansi(byte, cmd->line);
  			continue;
  		}
  
  		/* Handle escape mode */
  		if (atomic_test_and_clear_bit(&esc_state, ESC_ESC)) {
  			if (byte == ANSI_ESC) {
  				atomic_set_bit(&esc_state, ESC_ANSI);
  				atomic_set_bit(&esc_state, ESC_ANSI_FIRST);
  			}
  
  			continue;
  		}
  
  		/* Handle special control characters */
  		if (!isprint(byte)) {
  			switch (byte) {
  			case BS:
  			case DEL:
  				if (cur > 0) {
  					del_char(&cmd->line[--cur], end);
  				}
  				break;
  			case ESC:
  				atomic_set_bit(&esc_state, ESC_ESC);
  				break;
  			case '\r':
  				cmd->line[cur + end] = '\0';
  				uart_poll_out(uart_console_dev, '\r');
  				uart_poll_out(uart_console_dev, '\n');
  				cur = 0U;
  				end = 0U;
  				k_fifo_put(lines_queue, cmd);
  				cmd = NULL;
  				break;
  			case '\t':
  				if (completion_cb && !end) {
  					cur += completion_cb(cmd->line, cur);
  				}
  				break;
  			default:
  				break;
  			}
  
  			continue;
  		}
  
  		/* Ignore characters if there's no more buffer space */
  		if (cur + end < sizeof(cmd->line) - 1) {
  			insert_char(&cmd->line[cur++], byte, end);
  		}
  	}
  }
  
  static void console_input_init(void)
  {
  	u8_t c;
  
  	uart_irq_rx_disable(uart_console_dev);
  	uart_irq_tx_disable(uart_console_dev);
  
  	uart_irq_callback_set(uart_console_dev, uart_console_isr);
  
  	/* Drain the fifo */
  	while (uart_irq_rx_ready(uart_console_dev)) {
  		uart_fifo_read(uart_console_dev, &c, 1);
  	}
  
  	uart_irq_rx_enable(uart_console_dev);
  }
  
  void uart_register_input(struct k_fifo *avail, struct k_fifo *lines,
  			 u8_t (*completion)(char *str, u8_t len))
  {
  	avail_queue = avail;
  	lines_queue = lines;
  	completion_cb = completion;
  
  	console_input_init();
  }
  
  #else
  #define console_input_init(x) \
  	do {    /* nothing */ \
  	} while ((0))
  #define uart_register_input(x) \
  	do {    /* nothing */  \
  	} while ((0))
  #endif
  
  /**
   *
   * @brief Install printk/stdout hook for UART console output
   *
   * @return N/A
   */
  
  void uart_console_hook_install(void)
  {
  	__stdout_hook_install(console_out);
  	__printk_hook_install(console_out);
  }
  
  /**
   *
   * @brief Initialize one UART as the console/debug port
   *
   * @return 0 if successful, otherwise failed.
   */
  static int uart_console_init(struct device *arg)
  {
  
  	ARG_UNUSED(arg);
  
  	uart_console_dev = device_get_binding(CONFIG_UART_CONSOLE_ON_DEV_NAME);
  
  #if defined(CONFIG_USB_UART_CONSOLE) && defined(CONFIG_USB_UART_DTR_WAIT)
  	int ret;
  
  	ret = usb_enable(NULL);
  	if (ret != 0) {
  		return ret;
  	}
  
  	while (1) {
  		u32_t dtr = 0U;
  
  		uart_line_ctrl_get(uart_console_dev, UART_LINE_CTRL_DTR, &dtr);
  		if (dtr) {
  			break;
  		}
  	}
  	k_busy_wait(1000000);
  #endif
  
  	uart_console_hook_install();
  
  	return 0;
  }
  
  /* UART console initializes after the UART device itself */
  SYS_INIT(uart_console_init,
  #if defined(CONFIG_USB_UART_CONSOLE)
  	 APPLICATION,
  #elif defined(CONFIG_EARLY_CONSOLE)
  	 PRE_KERNEL_1,
  #else
  	 POST_KERNEL,
  #endif
  	 CONFIG_UART_CONSOLE_INIT_PRIORITY);
  