input: Add generic keyboard input handler

Add a module which understands converting key codes (or scan codes)
to ASCII characters. It includes FIFO support and can call back to
drivers to read new characters when its FIFO is empty.

Keycode maps are provided for un-modified, shift and ctrl keys.

The plan is to use this module where such mapping is required.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>

1 files changed, 147 insertions, 0 deletions

diff --git a/include/input.h b/include/input.h
new file mode 100644
index 0000000..31b1ef9
--- /dev/null
+++ b/include/input.h
@@ -0,0 +1,147 @@
+/*
+ * Keyboard input helper functions (too small to be called a layer)
+ *
+ * Copyright (c) 2011 The Chromium OS Authors.
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#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
+ */
+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 input handler with basic key maps.
+ *
+ * @param config	Input state
+ * @param leds		Initial LED value (INPUT_LED_ mask), 0 suggested
+ * @param repeat_delay_ms	Delay before key auto-repeat starts (in ms)
+ * @param repeat_rate_ms	Delay between successive key repeats (in ms)
+ * @return 0 if ok, -1 on error
+ */
+int input_init(struct input_config *config, int leds, int repeat_delay_ms,
+	       int repeat_rate_ms);
+
+#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