/*
   * Keyboard input helper functions (too small to be called a layer)
   *
   * Copyright (c) 2011 The Chromium OS Authors.
   *
   * SPDX-License-Identifier:	GPL-2.0+
   */
  
  #ifndef _INPUT_H
  #define _INPUT_H
  
  enum {
  	INPUT_MAX_MODIFIERS	= 4,
  	INPUT_BUFFER_LEN	= 16,
  };
  
  enum {
  	/* Keyboard LEDs */
  	INPUT_LED_SCROLL	= 1 << 0,
  	INPUT_LED_CAPS		= 1 << 1,
  	INPUT_LED_NUM		= 1 << 2,
  };
  
  /*
   * This table translates key codes to ASCII. Most of the entries are ASCII
   * codes, but entries after KEY_FIRST_MOD indicate that this key is a
   * modifier key, like shift, ctrl. KEY_FIRST_MOD + MOD_SHIFT is the shift
   * key, for example.
   */
  struct input_key_xlate {
  	/* keycode of the modifiers which select this table, -1 if none */
  	int left_keycode;
  	int right_keycode;
  	const uchar *xlate;	/* keycode to ASCII table */
  	int num_entries;	/* number of entries in this table */
  };
  
  struct input_config {
  	uchar fifo[INPUT_BUFFER_LEN];
  	int fifo_in, fifo_out;
  
  	/* Which modifiers are active (1 bit for each MOD_... value) */
  	uchar modifiers;
  	uchar flags;		/* active state keys (FLAGS_...) */
  	uchar leds;		/* active LEDS (INPUT_LED_...) */
  	uchar num_tables;	/* number of modifier tables */
  	int prev_keycodes[INPUT_BUFFER_LEN];	/* keys held last time */
  	int num_prev_keycodes;	/* number of prev keys */
  	struct input_key_xlate table[INPUT_MAX_MODIFIERS];
  
  	/**
  	 * Function the input helper calls to scan the keyboard
  	 *
  	 * @param config	Input state
  	 * @return 0 if no keys read, otherwise number of keys read, or 1 if
  	 *		unknown
  	 */
  	int (*read_keys)(struct input_config *config);
  	unsigned int next_repeat_ms;	/* Next time we repeat a key */
  	unsigned int repeat_delay_ms;	/* Time before autorepeat starts */
  	unsigned int repeat_rate_ms;	/* Autorepeat rate in ms */
  };
  
  struct stdio_dev;
  
  /**
   * Convert a list of key codes into ASCII and send them
   *
   * @param config	Input state
   * @param keycode	List of key codes to examine
   * @param num_keycodes	Number of key codes
   * @return number of ascii characters sent, or 0 if none, or -1 for an
   *	internal error
   */
  int input_send_keycodes(struct input_config *config, int keycode[], int count);
  
  /**
   * Add a new key translation table to the input
   *
   * @param config	Input state
   * @param left_keycode	Key to hold to get into this table
   * @param right_keycode	Another key to hold to get into this table
   * @param xlate		Conversion table from key codes to ASCII
   * @param num_entries	Number of entries in xlate table
   */
  int input_add_table(struct input_config *config, int left_keycode,
  		    int right_keycode, const uchar *xlate, int num_entries);
  
  /**
   * Test if keys are available to be read
   *
   * @param config	Input state
   * @return 0 if no keys available, 1 if keys are available
   */
  int input_tstc(struct input_config *config);
  
  /**
   * Read a key
   *
   * TODO: U-Boot wants 0 for no key, but Ctrl-@ is a valid key...
   *
   * @param config	Input state
   * @return key, or 0 if no key, or -1 if error
   */
  int input_getc(struct input_config *config);
  
  /**
   * Register a new device with stdio and switch to it if wanted
   *
   * @param dev	Pointer to device
   * @return 0 if ok, -1 on error
   */
  int input_stdio_register(struct stdio_dev *dev);
  
  /**
   * Set up the keyboard autorepeat delays
   *
   * @param repeat_delay_ms	Delay before key auto-repeat starts (in ms)
   * @param repeat_rate_ms	Delay between successive key repeats (in ms)
   */
  void input_set_delays(struct input_config *config, int repeat_delay_ms,
  	       int repeat_rate_ms);
  
  /**
   * Set up the input handler with basic key maps.
   *
   * @param config	Input state
   * @param leds		Initial LED value (INPUT_LED_ mask), 0 suggested
   * @return 0 if ok, -1 on error
   */
  int input_init(struct input_config *config, int leds);
  
  #ifdef CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
  extern int overwrite_console(void);
  #define OVERWRITE_CONSOLE overwrite_console()
  #else
  #define OVERWRITE_CONSOLE 0
  #endif /* CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE */
  
  #endif