Input: add driver for keyboard on AAED-2000 development board (ARM)

The keyboard is connected via GPIOs to the processor, and scanned
using a column sample register. The hardware provides no debouncing
mechanism, so the state of the keys is read KBDSCAN_STABLE_COUNT
times before being reported to the input layer.

The status of the keys needs to be polled because there is no
interrupt hooked to the lines. A workqueue is used for this.

Signed-off-by: Nicolas Bellido Y Ortega <ml@acolin.be>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

1 files changed, 203 insertions, 0 deletions

diff --git a/drivers/input/keyboard/aaed2000_kbd.c b/drivers/input/keyboard/aaed2000_kbd.c
new file mode 100644
index 000000000000..65fcb6af63a8
--- /dev/null
+++ b/drivers/input/keyboard/aaed2000_kbd.c
@@ -0,0 +1,203 @@
+/*
+ *  Keyboard driver for the AAED-2000 dev board
+ *
+ *  Copyright (c) 2006 Nicolas Bellido Y Ortega
+ *
+ *  Based on corgikbd.c
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/init.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/jiffies.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+
+#include <asm/arch/hardware.h>
+#include <asm/arch/aaed2000.h>
+
+#define KB_ROWS			12
+#define KB_COLS			8
+#define KB_ROWMASK(r)		(1 << (r))
+#define SCANCODE(r,c)		(((c) * KB_ROWS) + (r))
+#define NR_SCANCODES		(KB_COLS * KB_ROWS)
+
+#define SCAN_INTERVAL		(50) /* ms */
+#define KB_ACTIVATE_DELAY	(20) /* us */
+
+static unsigned char aaedkbd_keycode[NR_SCANCODES] = {
+	KEY_9, KEY_0, KEY_MINUS, KEY_EQUAL, KEY_BACKSPACE, 0, KEY_SPACE, KEY_KP6, 0, KEY_KPDOT, 0, 0,
+	KEY_K, KEY_M, KEY_O, KEY_DOT, KEY_SLASH, 0, KEY_F, 0, 0, 0, KEY_LEFTSHIFT, 0,
+	KEY_I, KEY_P, KEY_LEFTBRACE, KEY_RIGHTBRACE, KEY_BACKSLASH, 0, 0, 0, 0, 0, KEY_RIGHTSHIFT, 0,
+	KEY_8, KEY_L, KEY_SEMICOLON, KEY_APOSTROPHE, KEY_ENTER, 0, 0, 0, 0, 0, 0, 0,
+	KEY_J, KEY_H, KEY_B, KEY_KP8, KEY_KP4, 0, KEY_C, KEY_D, KEY_S, KEY_A, 0, KEY_CAPSLOCK,
+	KEY_Y, KEY_U, KEY_N, KEY_T, 0, 0, KEY_R, KEY_E, KEY_W, KEY_Q, 0, KEY_TAB,
+	KEY_7, KEY_6, KEY_G, 0, KEY_5, 0, KEY_4, KEY_3, KEY_2, KEY_1, 0, KEY_GRAVE,
+	0, 0, KEY_COMMA, 0, KEY_KP2, 0, KEY_V, KEY_LEFTALT, KEY_X, KEY_Z, 0, KEY_LEFTCTRL
+};
+
+struct aaedkbd {
+	unsigned char keycode[ARRAY_SIZE(aaedkbd_keycode)];
+	struct input_dev *input;
+	struct work_struct workq;
+	int kbdscan_state[KB_COLS];
+	int kbdscan_count[KB_COLS];
+};
+
+#define KBDSCAN_STABLE_COUNT 2
+
+static void aaedkbd_report_col(struct aaedkbd *aaedkbd,
+				unsigned int col, unsigned int rowd)
+{
+	unsigned int scancode, pressed;
+	unsigned int row;
+
+	for (row = 0; row < KB_ROWS; row++) {
+		scancode = SCANCODE(row, col);
+		pressed = rowd & KB_ROWMASK(row);
+
+		input_report_key(aaedkbd->input, aaedkbd->keycode[scancode], pressed);
+	}
+}
+
+/* Scan the hardware keyboard and push any changes up through the input layer */
+static void aaedkbd_work(void *data)
+{
+	struct aaedkbd *aaedkbd = data;
+	unsigned int col, rowd;
+
+	col = 0;
+	do {
+		AAEC_GPIO_KSCAN = col + 8;
+		udelay(KB_ACTIVATE_DELAY);
+		rowd = AAED_EXT_GPIO & AAED_EGPIO_KBD_SCAN;
+
+		if (rowd != aaedkbd->kbdscan_state[col]) {
+			aaedkbd->kbdscan_count[col] = 0;
+			aaedkbd->kbdscan_state[col] = rowd;
+		} else if (++aaedkbd->kbdscan_count[col] >= KBDSCAN_STABLE_COUNT) {
+			aaedkbd_report_col(aaedkbd, col, rowd);
+			col++;
+		}
+	} while (col < KB_COLS);
+
+	AAEC_GPIO_KSCAN = 0x07;
+	input_sync(aaedkbd->input);
+
+	schedule_delayed_work(&aaedkbd->workq, msecs_to_jiffies(SCAN_INTERVAL));
+}
+
+static int aaedkbd_open(struct input_dev *indev)
+{
+	struct aaedkbd *aaedkbd = indev->private;
+
+	schedule_delayed_work(&aaedkbd->workq, msecs_to_jiffies(SCAN_INTERVAL));
+
+	return 0;
+}
+
+static void aaedkbd_close(struct input_dev *indev)
+{
+	struct aaedkbd *aaedkbd = indev->private;
+
+	cancel_delayed_work(&aaedkbd->workq);
+	flush_scheduled_work();
+}
+
+static int __devinit aaedkbd_probe(struct platform_device *pdev)
+{
+	struct aaedkbd *aaedkbd;
+	struct input_dev *input_dev;
+	int i;
+	int error;
+
+	aaedkbd = kzalloc(sizeof(struct aaedkbd), GFP_KERNEL);
+	input_dev = input_allocate_device();
+	if (!aaedkbd || !input_dev) {
+		error = -ENOMEM;
+		goto fail;
+	}
+
+	platform_set_drvdata(pdev, aaedkbd);
+
+	aaedkbd->input = input_dev;
+
+	/* Init keyboard rescan workqueue */
+	INIT_WORK(&aaedkbd->workq, aaedkbd_work, aaedkbd);
+
+	memcpy(aaedkbd->keycode, aaedkbd_keycode, sizeof(aaedkbd->keycode));
+
+	input_dev->name = "AAED-2000 Keyboard";
+	input_dev->phys = "aaedkbd/input0";
+	input_dev->id.bustype = BUS_HOST;
+	input_dev->id.vendor = 0x0001;
+	input_dev->id.product = 0x0001;
+	input_dev->id.version = 0x0100;
+	input_dev->cdev.dev = &pdev->dev;
+	input_dev->private = aaedkbd;
+
+	input_dev->evbit[0] = BIT(EV_KEY) | BIT(EV_REP);
+	input_dev->keycode = aaedkbd->keycode;
+	input_dev->keycodesize = sizeof(unsigned char);
+	input_dev->keycodemax = ARRAY_SIZE(aaedkbd_keycode);
+
+	for (i = 0; i < ARRAY_SIZE(aaedkbd_keycode); i++)
+		set_bit(aaedkbd->keycode[i], input_dev->keybit);
+	clear_bit(0, input_dev->keybit);
+
+	input_dev->open = aaedkbd_open;
+	input_dev->close = aaedkbd_close;
+
+	error = input_register_device(aaedkbd->input);
+	if (error)
+		goto fail;
+
+	return 0;
+
+ fail:	kfree(aaedkbd);
+	input_free_device(input_dev);
+	return error;
+}
+
+static int __devexit aaedkbd_remove(struct platform_device *pdev)
+{
+	struct aaedkbd *aaedkbd = platform_get_drvdata(pdev);
+
+	input_unregister_device(aaedkbd->input);
+	kfree(aaedkbd);
+
+	return 0;
+}
+
+static struct platform_driver aaedkbd_driver = {
+	.probe		= aaedkbd_probe,
+	.remove		= __devexit_p(aaedkbd_remove),
+	.driver		= {
+		.name	= "aaed2000-keyboard",
+	},
+};
+
+static int __init aaedkbd_init(void)
+{
+	return platform_driver_register(&aaedkbd_driver);
+}
+
+static void __exit aaedkbd_exit(void)
+{
+	platform_driver_unregister(&aaedkbd_driver);
+}
+
+module_init(aaedkbd_init);
+module_exit(aaedkbd_exit);
+
+MODULE_AUTHOR("Nicolas Bellido Y Ortega");
+MODULE_DESCRIPTION("AAED-2000 Keyboard Driver");
+MODULE_LICENSE("GPLv2");