Input: add driver for MIPS Cobalt back panel buttons

Tested on Cobalt Qube2.

Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/drivers/input/misc/cobalt_btns.c b/drivers/input/misc/cobalt_btns.c
new file mode 100644
index 0000000..b14f49e
--- /dev/null
+++ b/drivers/input/misc/cobalt_btns.c
@@ -0,0 +1,209 @@
+/*
+ *  Cobalt button interface driver.
+ *
+ *  Copyright (C) 2007  Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
+ *
+ *  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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+#include <linux/init.h>
+#include <linux/input.h>
+#include <linux/ioport.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/jiffies.h>
+#include <linux/timer.h>
+
+#define BUTTONS_POLL_INTERVAL	30	/* msec */
+#define BUTTONS_COUNT_THRESHOLD	3
+#define BUTTONS_STATUS_MASK	0xfe000000
+
+struct buttons_dev {
+	struct input_dev *input;
+	void __iomem *reg;
+};
+
+struct buttons_map {
+	uint32_t mask;
+	int keycode;
+	int count;
+};
+
+static struct buttons_map buttons_map[] = {
+	{ 0x02000000, KEY_RESTART, },
+	{ 0x04000000, KEY_LEFT, },
+	{ 0x08000000, KEY_UP, },
+	{ 0x10000000, KEY_DOWN, },
+	{ 0x20000000, KEY_RIGHT, },
+	{ 0x40000000, KEY_ENTER, },
+	{ 0x80000000, KEY_SELECT, },
+};
+
+static struct resource cobalt_buttons_resource __initdata = {
+	.start	= 0x1d000000,
+	.end	= 0x1d000003,
+	.flags	= IORESOURCE_MEM,
+};
+
+static struct platform_device *cobalt_buttons_device;
+
+static struct timer_list buttons_timer;
+
+static void handle_buttons(unsigned long data)
+{
+	struct buttons_map *button = buttons_map;
+	struct buttons_dev *bdev;
+	uint32_t status;
+	int i;
+
+	bdev = (struct buttons_dev *)data;
+	status = readl(bdev->reg);
+	status = ~status & BUTTONS_STATUS_MASK;
+
+	for (i = 0; i < ARRAY_SIZE(buttons_map); i++) {
+		if (status & button->mask) {
+			button->count++;
+		} else {
+			if (button->count >= BUTTONS_COUNT_THRESHOLD) {
+				input_report_key(bdev->input, button->keycode, 0);
+				input_sync(bdev->input);
+			}
+			button->count = 0;
+		}
+
+		if (button->count == BUTTONS_COUNT_THRESHOLD) {
+			input_report_key(bdev->input, button->keycode, 1);
+			input_sync(bdev->input);
+		}
+
+		button++;
+	}
+
+	mod_timer(&buttons_timer, jiffies + msecs_to_jiffies(BUTTONS_POLL_INTERVAL));
+}
+
+static int cobalt_buttons_open(struct input_dev *dev)
+{
+	mod_timer(&buttons_timer, jiffies + msecs_to_jiffies(BUTTONS_POLL_INTERVAL));
+
+	return 0;
+}
+
+static void cobalt_buttons_close(struct input_dev *dev)
+{
+	del_timer_sync(&buttons_timer);
+}
+
+static int __devinit cobalt_buttons_probe(struct platform_device *pdev)
+{
+	struct buttons_dev *bdev;
+	struct input_dev *input;
+	struct resource *res;
+	int error, i;
+
+	bdev = kzalloc(sizeof(struct buttons_dev), GFP_KERNEL);
+	input = input_allocate_device();
+	if (!bdev || !input) {
+		error = -ENOMEM;
+		goto err_free_mem;
+	}
+
+	input->name = "Cobalt buttons";
+	input->phys = "cobalt/input0";
+	input->id.bustype = BUS_HOST;
+	input->cdev.dev = &pdev->dev;
+	input->open = cobalt_buttons_open;
+	input->close = cobalt_buttons_close;
+
+	input->evbit[0] = BIT(EV_KEY);
+	for (i = 0; i < ARRAY_SIZE(buttons_map); i++) {
+		set_bit(buttons_map[i].keycode, input->keybit);
+		buttons_map[i].count = 0;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		error = -EBUSY;
+		goto err_free_mem;
+	}
+
+	bdev->input = input;
+	bdev->reg = ioremap(res->start, res->end - res->start + 1);
+	dev_set_drvdata(&pdev->dev, bdev);
+
+	setup_timer(&buttons_timer, handle_buttons, (unsigned long)bdev);
+
+	error = input_register_device(input);
+	if (error)
+		goto err_iounmap;
+
+	return 0;
+
+ err_iounmap:
+	iounmap(bdev->reg);
+ err_free_mem:
+	input_free_device(input);
+	kfree(bdev);
+	dev_set_drvdata(&pdev->dev, NULL);
+	return error;
+}
+
+static int __devexit cobalt_buttons_remove(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct buttons_dev *bdev = dev_get_drvdata(dev);
+
+	input_unregister_device(bdev->input);
+	iounmap(bdev->reg);
+	kfree(bdev);
+	dev_set_drvdata(dev, NULL);
+
+	return 0;
+}
+
+static struct platform_driver cobalt_buttons_driver = {
+	.probe	= cobalt_buttons_probe,
+	.remove	= __devexit_p(cobalt_buttons_remove),
+	.driver	= {
+		.name	= "Cobalt buttons",
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init cobalt_buttons_init(void)
+{
+	int retval;
+
+	cobalt_buttons_device = platform_device_register_simple("Cobalt buttons", -1,
+	                                                        &cobalt_buttons_resource, 1);
+	if (IS_ERR(cobalt_buttons_device)) {
+		retval = PTR_ERR(cobalt_buttons_device);
+		return retval;
+	}
+
+	retval = platform_driver_register(&cobalt_buttons_driver);
+	if (retval < 0)
+		platform_device_unregister(cobalt_buttons_device);
+
+	return retval;
+}
+
+static void __exit cobalt_buttons_exit(void)
+{
+	platform_driver_unregister(&cobalt_buttons_driver);
+	platform_device_unregister(cobalt_buttons_device);
+}
+
+module_init(cobalt_buttons_init);
+module_exit(cobalt_buttons_exit);