From 6730377482c05a1742abb92f1463701f5d084a27 Mon Sep 17 00:00:00 2001
From: =?utf-8?q?Arve=20Hj=C3=B8nnev=C3=A5g?= <arve@android.com>
Date: Wed, 15 Oct 2008 18:23:47 -0700
Subject: [PATCH 086/134] Input: Generic GPIO Input device.
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 8bit

Supports keyboard matrixces, direct inputs, direct outputs and axes connected to gpios.

Signed-off-by: Arve Hjønnevåg <arve@android.com>
Signed-off-by: Nick Pelly <npelly@google.com>
---
 drivers/input/misc/Kconfig       |    5 +
 drivers/input/misc/Makefile      |    1 +
 drivers/input/misc/gpio_axis.c   |  180 +++++++++++++++++
 drivers/input/misc/gpio_event.c  |  224 +++++++++++++++++++++
 drivers/input/misc/gpio_input.c  |  343 ++++++++++++++++++++++++++++++++
 drivers/input/misc/gpio_matrix.c |  406 ++++++++++++++++++++++++++++++++++++++
 drivers/input/misc/gpio_output.c |   84 ++++++++
 include/linux/gpio_event.h       |  154 ++++++++++++++
 8 files changed, 1397 insertions(+), 0 deletions(-)
 create mode 100644 drivers/input/misc/gpio_axis.c
 create mode 100644 drivers/input/misc/gpio_event.c
 create mode 100644 drivers/input/misc/gpio_input.c
 create mode 100644 drivers/input/misc/gpio_matrix.c
 create mode 100644 drivers/input/misc/gpio_output.c
 create mode 100644 include/linux/gpio_event.h

--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -212,6 +212,11 @@ config INPUT_SGI_BTNS
 	  To compile this driver as a module, choose M here: the
 	  module will be called sgi_btns.
 
+config INPUT_GPIO
+	tristate "GPIO driver support"
+	help
+	  Say Y here if you want to support gpio based keys, wheels etc...
+
 config HP_SDC_RTC
 	tristate "HP SDC Real Time Clock"
 	depends on (GSC || HP300) && SERIO
--- a/drivers/input/misc/Makefile
+++ b/drivers/input/misc/Makefile
@@ -25,3 +25,5 @@ obj-$(CONFIG_INPUT_UINPUT)		+= uinput.o
 obj-$(CONFIG_INPUT_WISTRON_BTNS)	+= wistron_btns.o
 obj-$(CONFIG_INPUT_YEALINK)		+= yealink.o
 obj-$(CONFIG_INPUT_GPIO_BUTTONS)	+= gpio_buttons.o
+obj-$(CONFIG_INPUT_GPIO)		+= gpio_event.o gpio_matrix.o gpio_input.o gpio_output.o gpio_axis.o
+
--- /dev/null
+++ b/drivers/input/misc/gpio_axis.c
@@ -0,0 +1,180 @@
+/* drivers/input/misc/gpio_axis.c
+ *
+ * Copyright (C) 2007 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/gpio.h>
+#include <linux/gpio_event.h>
+#include <linux/interrupt.h>
+
+struct gpio_axis_state {
+	struct input_dev *input_dev;
+	struct gpio_event_axis_info *info;
+	uint32_t pos;
+};
+
+uint16_t gpio_axis_4bit_gray_map_table[] = {
+	[0x0] = 0x0, [0x1] = 0x1, /* 0000 0001 */
+	[0x3] = 0x2, [0x2] = 0x3, /* 0011 0010 */
+	[0x6] = 0x4, [0x7] = 0x5, /* 0110 0111 */
+	[0x5] = 0x6, [0x4] = 0x7, /* 0101 0100 */
+	[0xc] = 0x8, [0xd] = 0x9, /* 1100 1101 */
+	[0xf] = 0xa, [0xe] = 0xb, /* 1111 1110 */
+	[0xa] = 0xc, [0xb] = 0xd, /* 1010 1011 */
+	[0x9] = 0xe, [0x8] = 0xf, /* 1001 1000 */
+};
+uint16_t gpio_axis_4bit_gray_map(struct gpio_event_axis_info *info, uint16_t in)
+{
+	return gpio_axis_4bit_gray_map_table[in];
+}
+
+uint16_t gpio_axis_5bit_singletrack_map_table[] = {
+	[0x10] = 0x00, [0x14] = 0x01, [0x1c] = 0x02, /*     10000 10100 11100 */
+	[0x1e] = 0x03, [0x1a] = 0x04, [0x18] = 0x05, /*     11110 11010 11000 */
+	[0x08] = 0x06, [0x0a] = 0x07, [0x0e] = 0x08, /*    01000 01010 01110  */
+	[0x0f] = 0x09, [0x0d] = 0x0a, [0x0c] = 0x0b, /*    01111 01101 01100  */
+	[0x04] = 0x0c, [0x05] = 0x0d, [0x07] = 0x0e, /*   00100 00101 00111   */
+	[0x17] = 0x0f, [0x16] = 0x10, [0x06] = 0x11, /*   10111 10110 00110   */
+	[0x02] = 0x12, [0x12] = 0x13, [0x13] = 0x14, /*  00010 10010 10011    */
+	[0x1b] = 0x15, [0x0b] = 0x16, [0x03] = 0x17, /*  11011 01011 00011    */
+	[0x01] = 0x18, [0x09] = 0x19, [0x19] = 0x1a, /* 00001 01001 11001     */
+	[0x1d] = 0x1b, [0x15] = 0x1c, [0x11] = 0x1d, /* 11101 10101 10001     */
+};
+uint16_t gpio_axis_5bit_singletrack_map(
+	struct gpio_event_axis_info *info, uint16_t in)
+{
+	return gpio_axis_5bit_singletrack_map_table[in];
+}
+
+static void gpio_event_update_axis(struct gpio_axis_state *as, int report)
+{
+	struct gpio_event_axis_info *ai = as->info;
+	int i;
+	int change;
+	uint16_t state = 0;
+	uint16_t pos;
+	uint16_t old_pos = as->pos;
+	for (i = ai->count - 1; i >= 0; i--)
+		state = (state << 1) | gpio_get_value(ai->gpio[i]);
+	pos = ai->map(ai, state);
+	if (ai->flags & GPIOEAF_PRINT_RAW)
+		pr_info("axis %d-%d raw %x, pos %d -> %d\n",
+			ai->type, ai->code, state, old_pos, pos);
+	if (report && pos != old_pos) {
+		if (ai->type == EV_REL) {
+			change = (ai->decoded_size + pos - old_pos) %
+				  ai->decoded_size;
+			if (change > ai->decoded_size / 2)
+				change -= ai->decoded_size;
+			if (change == ai->decoded_size / 2) {
+				if (ai->flags & GPIOEAF_PRINT_EVENT)
+					pr_info("axis %d-%d unknown direction, "
+						"pos %d -> %d\n", ai->type,
+						ai->code, old_pos, pos);
+				change = 0; /* no closest direction */
+			}
+			if (ai->flags & GPIOEAF_PRINT_EVENT)
+				pr_info("axis %d-%d change %d\n",
+					ai->type, ai->code, change);
+			input_report_rel(as->input_dev, ai->code, change);
+		} else {
+			if (ai->flags & GPIOEAF_PRINT_EVENT)
+				pr_info("axis %d-%d now %d\n",
+					ai->type, ai->code, pos);
+			input_event(as->input_dev, ai->type, ai->code, pos);
+		}
+		input_sync(as->input_dev);
+	}
+	as->pos = pos;
+}
+
+static irqreturn_t gpio_axis_irq_handler(int irq, void *dev_id)
+{
+	struct gpio_axis_state *as = dev_id;
+	gpio_event_update_axis(as, 1);
+	return IRQ_HANDLED;
+}
+
+int gpio_event_axis_func(struct input_dev *input_dev,
+			 struct gpio_event_info *info, void **data, int func)
+{
+	int ret;
+	int i;
+	int irq;
+	struct gpio_event_axis_info *ai;
+	struct gpio_axis_state *as;
+
+	ai = container_of(info, struct gpio_event_axis_info, info);
+	if (func == GPIO_EVENT_FUNC_SUSPEND) {
+		for (i = 0; i < ai->count; i++)
+			disable_irq(gpio_to_irq(ai->gpio[i]));
+		return 0;
+	}
+	if (func == GPIO_EVENT_FUNC_RESUME) {
+		for (i = 0; i < ai->count; i++)
+			enable_irq(gpio_to_irq(ai->gpio[i]));
+		return 0;
+	}
+
+	if (func == GPIO_EVENT_FUNC_INIT) {
+		*data = as = kmalloc(sizeof(*as), GFP_KERNEL);
+		if (as == NULL) {
+			ret = -ENOMEM;
+			goto err_alloc_axis_state_failed;
+		}
+		as->input_dev = input_dev;
+		as->info = ai;
+
+		input_set_capability(input_dev, ai->type, ai->code);
+		if (ai->type == EV_ABS) {
+			input_set_abs_params(input_dev, ai->code, 0,
+					     ai->decoded_size - 1, 0, 0);
+		}
+		for (i = 0; i < ai->count; i++) {
+			ret = gpio_request(ai->gpio[i], "gpio_event_axis");
+			if (ret < 0)
+				goto err_request_gpio_failed;
+			ret = gpio_direction_input(ai->gpio[i]);
+			if (ret < 0)
+				goto err_gpio_direction_input_failed;
+			ret = irq = gpio_to_irq(ai->gpio[i]);
+			if (ret < 0)
+				goto err_get_irq_num_failed;
+			ret = request_irq(irq, gpio_axis_irq_handler,
+					  IRQF_TRIGGER_RISING |
+					  IRQF_TRIGGER_FALLING,
+					  "gpio_event_axis", as);
+			if (ret < 0)
+				goto err_request_irq_failed;
+		}
+		gpio_event_update_axis(as, 0);
+		return 0;
+	}
+
+	ret = 0;
+	as = *data;
+	for (i = ai->count - 1; i >= 0; i--) {
+		free_irq(gpio_to_irq(ai->gpio[i]), as);
+err_request_irq_failed:
+err_get_irq_num_failed:
+err_gpio_direction_input_failed:
+		gpio_free(ai->gpio[i]);
+err_request_gpio_failed:
+		;
+	}
+	kfree(as);
+	*data = NULL;
+err_alloc_axis_state_failed:
+	return ret;
+}
--- /dev/null
+++ b/drivers/input/misc/gpio_event.c
@@ -0,0 +1,224 @@
+/* drivers/input/misc/gpio_event.c
+ *
+ * Copyright (C) 2007 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+
+#include <linux/earlysuspend.h>
+#include <linux/module.h>
+#include <linux/input.h>
+#include <linux/gpio_event.h>
+#include <linux/hrtimer.h>
+#include <linux/platform_device.h>
+
+struct gpio_event {
+	struct input_dev *input_dev;
+	const struct gpio_event_platform_data *info;
+	struct early_suspend early_suspend;
+	void *state[0];
+};
+
+static int gpio_input_event(
+	struct input_dev *dev, unsigned int type, unsigned int code, int value)
+{
+	int i;
+	int ret = 0;
+	int tmp_ret;
+	struct gpio_event_info **ii;
+	struct gpio_event *ip = input_get_drvdata(dev);
+
+	for (i = 0, ii = ip->info->info; i < ip->info->info_count; i++, ii++) {
+		if ((*ii)->event) {
+			tmp_ret = (*ii)->event(ip->input_dev, *ii,
+					&ip->state[i], type, code, value);
+			if (tmp_ret)
+				ret = tmp_ret;
+		}
+	}
+	return ret;
+}
+
+static int gpio_event_call_all_func(struct gpio_event *ip, int func)
+{
+	int i;
+	int ret;
+	struct gpio_event_info **ii;
+
+	if (func == GPIO_EVENT_FUNC_INIT || func == GPIO_EVENT_FUNC_RESUME) {
+		ii = ip->info->info;
+		for (i = 0; i < ip->info->info_count; i++, ii++) {
+			if ((*ii)->func == NULL) {
+				ret = -ENODEV;
+				pr_err("gpio_event_probe: Incomplete pdata, "
+					"no function\n");
+				goto err_no_func;
+			}
+			ret = (*ii)->func(ip->input_dev, *ii, &ip->state[i],
+					  func);
+			if (ret) {
+				pr_err("gpio_event_probe: function failed\n");
+				goto err_func_failed;
+			}
+		}
+		return 0;
+	}
+
+	ret = 0;
+	i = ip->info->info_count;
+	ii = ip->info->info + i;
+	while (i > 0) {
+		i--;
+		ii--;
+		(*ii)->func(ip->input_dev, *ii, &ip->state[i], func & ~1);
+err_func_failed:
+err_no_func:
+		;
+	}
+	return ret;
+}
+
+#ifdef CONFIG_HAS_EARLYSUSPEND
+void gpio_event_suspend(struct early_suspend *h)
+{
+	struct gpio_event *ip;
+	ip = container_of(h, struct gpio_event, early_suspend);
+	gpio_event_call_all_func(ip, GPIO_EVENT_FUNC_SUSPEND);
+	ip->info->power(ip->info, 0);
+}
+
+void gpio_event_resume(struct early_suspend *h)
+{
+	struct gpio_event *ip;
+	ip = container_of(h, struct gpio_event, early_suspend);
+	ip->info->power(ip->info, 1);
+	gpio_event_call_all_func(ip, GPIO_EVENT_FUNC_RESUME);
+}
+#endif
+
+static int __init gpio_event_probe(struct platform_device *pdev)
+{
+	int err;
+	struct gpio_event *ip;
+	struct input_dev *input_dev;
+	struct gpio_event_platform_data *event_info;
+
+	event_info = pdev->dev.platform_data;
+	if (event_info == NULL) {
+		pr_err("gpio_event_probe: No pdata\n");
+		return -ENODEV;
+	}
+	if (event_info->name == NULL ||
+	   event_info->info == NULL ||
+	   event_info->info_count == 0) {
+		pr_err("gpio_event_probe: Incomplete pdata\n");
+		return -ENODEV;
+	}
+	ip = kzalloc(sizeof(*ip) +
+		     sizeof(ip->state[0]) * event_info->info_count, GFP_KERNEL);
+	if (ip == NULL) {
+		err = -ENOMEM;
+		pr_err("gpio_event_probe: Failed to allocate private data\n");
+		goto err_kp_alloc_failed;
+	}
+	platform_set_drvdata(pdev, ip);
+
+	input_dev = input_allocate_device();
+	if (input_dev == NULL) {
+		err = -ENOMEM;
+		pr_err("gpio_event_probe: Failed to allocate input device\n");
+		goto err_input_dev_alloc_failed;
+	}
+	input_set_drvdata(input_dev, ip);
+	ip->input_dev = input_dev;
+	ip->info = event_info;
+	if (event_info->power) {
+#ifdef CONFIG_HAS_EARLYSUSPEND
+		ip->early_suspend.level = EARLY_SUSPEND_LEVEL_BLANK_SCREEN + 1;
+		ip->early_suspend.suspend = gpio_event_suspend;
+		ip->early_suspend.resume = gpio_event_resume;
+		register_early_suspend(&ip->early_suspend);
+#endif
+		ip->info->power(ip->info, 1);
+	}
+
+	input_dev->name = ip->info->name;
+	input_dev->event = gpio_input_event;
+
+	err = gpio_event_call_all_func(ip, GPIO_EVENT_FUNC_INIT);
+	if (err)
+		goto err_call_all_func_failed;
+
+	err = input_register_device(input_dev);
+	if (err) {
+		pr_err("gpio_event_probe: Unable to register %s input device\n",
+			input_dev->name);
+		goto err_input_register_device_failed;
+	}
+
+	return 0;
+
+err_input_register_device_failed:
+	gpio_event_call_all_func(ip, GPIO_EVENT_FUNC_UNINIT);
+err_call_all_func_failed:
+	if (event_info->power) {
+#ifdef CONFIG_HAS_EARLYSUSPEND
+		unregister_early_suspend(&ip->early_suspend);
+#endif
+		ip->info->power(ip->info, 0);
+	}
+	input_free_device(input_dev);
+err_input_dev_alloc_failed:
+	kfree(ip);
+err_kp_alloc_failed:
+	return err;
+}
+
+static int gpio_event_remove(struct platform_device *pdev)
+{
+	struct gpio_event *ip = platform_get_drvdata(pdev);
+
+	gpio_event_call_all_func(ip, GPIO_EVENT_FUNC_UNINIT);
+	if (ip->info->power) {
+#ifdef CONFIG_HAS_EARLYSUSPEND
+		unregister_early_suspend(&ip->early_suspend);
+#endif
+		ip->info->power(ip->info, 0);
+	}
+	input_unregister_device(ip->input_dev);
+	kfree(ip);
+	return 0;
+}
+
+static struct platform_driver gpio_event_driver = {
+	.probe		= gpio_event_probe,
+	.remove		= gpio_event_remove,
+	.driver		= {
+		.name	= GPIO_EVENT_DEV_NAME,
+	},
+};
+
+static int __devinit gpio_event_init(void)
+{
+	return platform_driver_register(&gpio_event_driver);
+}
+
+static void __exit gpio_event_exit(void)
+{
+	platform_driver_unregister(&gpio_event_driver);
+}
+
+module_init(gpio_event_init);
+module_exit(gpio_event_exit);
+
+MODULE_DESCRIPTION("GPIO Event Driver");
+MODULE_LICENSE("GPL");
+
--- /dev/null
+++ b/drivers/input/misc/gpio_input.c
@@ -0,0 +1,343 @@
+/* drivers/input/misc/gpio_input.c
+ *
+ * Copyright (C) 2007 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/gpio.h>
+#include <linux/gpio_event.h>
+#include <linux/hrtimer.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/wakelock.h>
+
+enum {
+	DEBOUNCE_UNSTABLE     = BIT(0),	/* Got irq, while debouncing */
+	DEBOUNCE_PRESSED      = BIT(1),
+	DEBOUNCE_NOTPRESSED   = BIT(2),
+	DEBOUNCE_WAIT_IRQ     = BIT(3),	/* Stable irq state */
+	DEBOUNCE_POLL         = BIT(4),	/* Stable polling state */
+
+	DEBOUNCE_UNKNOWN =
+		DEBOUNCE_PRESSED | DEBOUNCE_NOTPRESSED,
+};
+
+struct gpio_key_state {
+	struct gpio_input_state *ds;
+	uint8_t debounce;
+};
+
+struct gpio_input_state {
+	struct input_dev *input_dev;
+	const struct gpio_event_input_info *info;
+	struct hrtimer timer;
+	int use_irq;
+	int debounce_count;
+	spinlock_t irq_lock;
+	struct wake_lock wake_lock;
+	struct gpio_key_state key_state[0];
+};
+
+static enum hrtimer_restart gpio_event_input_timer_func(struct hrtimer *timer)
+{
+	int i;
+	int pressed;
+	struct gpio_input_state *ds =
+		container_of(timer, struct gpio_input_state, timer);
+	unsigned gpio_flags = ds->info->flags;
+	unsigned npolarity;
+	int nkeys = ds->info->keymap_size;
+	const struct gpio_event_direct_entry *key_entry;
+	struct gpio_key_state *key_state;
+	unsigned long irqflags;
+	uint8_t debounce;
+
+#if 0
+	key_entry = kp->keys_info->keymap;
+	key_state = kp->key_state;
+	for (i = 0; i < nkeys; i++, key_entry++, key_state++)
+		pr_info("gpio_read_detect_status %d %d\n", key_entry->gpio,
+			gpio_read_detect_status(key_entry->gpio));
+#endif
+	key_entry = ds->info->keymap;
+	key_state = ds->key_state;
+	spin_lock_irqsave(&ds->irq_lock, irqflags);
+	for (i = 0; i < nkeys; i++, key_entry++, key_state++) {
+		debounce = key_state->debounce;
+		if (debounce & DEBOUNCE_WAIT_IRQ)
+			continue;
+		if (key_state->debounce & DEBOUNCE_UNSTABLE) {
+			debounce = key_state->debounce = DEBOUNCE_UNKNOWN;
+			enable_irq(gpio_to_irq(key_entry->gpio));
+			pr_info("gpio_keys_scan_keys: key %x-%x, %d "
+				"(%d) continue debounce\n",
+				ds->info->type, key_entry->code,
+				i, key_entry->gpio);
+		}
+		npolarity = !(gpio_flags & GPIOEDF_ACTIVE_HIGH);
+		pressed = gpio_get_value(key_entry->gpio) ^ npolarity;
+		if (debounce & DEBOUNCE_POLL) {
+			if (pressed == !(debounce & DEBOUNCE_PRESSED)) {
+				ds->debounce_count++;
+				key_state->debounce = DEBOUNCE_UNKNOWN;
+				if (gpio_flags & GPIOEDF_PRINT_KEY_DEBOUNCE)
+					pr_info("gpio_keys_scan_keys: key %x-"
+						"%x, %d (%d) start debounce\n",
+						ds->info->type, key_entry->code,
+						i, key_entry->gpio);
+			}
+			continue;
+		}
+		if (pressed && (debounce & DEBOUNCE_NOTPRESSED)) {
+			if (gpio_flags & GPIOEDF_PRINT_KEY_DEBOUNCE)
+				pr_info("gpio_keys_scan_keys: key %x-%x, %d "
+					"(%d) debounce pressed 1\n",
+					ds->info->type, key_entry->code,
+					i, key_entry->gpio);
+			key_state->debounce = DEBOUNCE_PRESSED;
+			continue;
+		}
+		if (!pressed && (debounce & DEBOUNCE_PRESSED)) {
+			if (gpio_flags & GPIOEDF_PRINT_KEY_DEBOUNCE)
+				pr_info("gpio_keys_scan_keys: key %x-%x, %d "
+					"(%d) debounce pressed 0\n",
+					ds->info->type, key_entry->code,
+					i, key_entry->gpio);
+			key_state->debounce = DEBOUNCE_NOTPRESSED;
+			continue;
+		}
+		/* key is stable */
+		ds->debounce_count--;
+		if (ds->use_irq)
+			key_state->debounce |= DEBOUNCE_WAIT_IRQ;
+		else
+			key_state->debounce |= DEBOUNCE_POLL;
+		if (gpio_flags & GPIOEDF_PRINT_KEYS)
+			pr_info("gpio_keys_scan_keys: key %x-%x, %d (%d) "
+				"changed to %d\n", ds->info->type,
+				key_entry->code, i, key_entry->gpio, pressed);
+		input_event(ds->input_dev, ds->info->type,
+			    key_entry->code, pressed);
+	}
+
+#if 0
+	key_entry = kp->keys_info->keymap;
+	key_state = kp->key_state;
+	for (i = 0; i < nkeys; i++, key_entry++, key_state++) {
+		pr_info("gpio_read_detect_status %d %d\n", key_entry->gpio,
+			gpio_read_detect_status(key_entry->gpio));
+	}
+#endif
+
+	if (ds->debounce_count)
+		hrtimer_start(timer, ds->info->debounce_time, HRTIMER_MODE_REL);
+	else if (!ds->use_irq)
+		hrtimer_start(timer, ds->info->poll_time, HRTIMER_MODE_REL);
+	else
+		wake_unlock(&ds->wake_lock);
+
+	spin_unlock_irqrestore(&ds->irq_lock, irqflags);
+
+	return HRTIMER_NORESTART;
+}
+
+static irqreturn_t gpio_event_input_irq_handler(int irq, void *dev_id)
+{
+	struct gpio_key_state *ks = dev_id;
+	struct gpio_input_state *ds = ks->ds;
+	int keymap_index = ks - ds->key_state;
+	const struct gpio_event_direct_entry *key_entry;
+	unsigned long irqflags;
+	int pressed;
+
+	if (!ds->use_irq)
+		return IRQ_HANDLED;
+
+	key_entry = &ds->info->keymap[keymap_index];
+
+	if (ds->info->debounce_time.tv64) {
+		spin_lock_irqsave(&ds->irq_lock, irqflags);
+		if (ks->debounce & DEBOUNCE_WAIT_IRQ) {
+			ks->debounce = DEBOUNCE_UNKNOWN;
+			if (ds->debounce_count++ == 0) {
+				wake_lock(&ds->wake_lock);
+				hrtimer_start(
+					&ds->timer, ds->info->debounce_time,
+					HRTIMER_MODE_REL);
+			}
+			if (ds->info->flags & GPIOEDF_PRINT_KEY_DEBOUNCE)
+				pr_info("gpio_event_input_irq_handler: "
+					"key %x-%x, %d (%d) start debounce\n",
+					ds->info->type, key_entry->code,
+					keymap_index, key_entry->gpio);
+		} else {
+			disable_irq(irq);
+			ks->debounce = DEBOUNCE_UNSTABLE;
+		}
+		spin_unlock_irqrestore(&ds->irq_lock, irqflags);
+	} else {
+		pressed = gpio_get_value(key_entry->gpio) ^
+			!(ds->info->flags & GPIOEDF_ACTIVE_HIGH);
+		if (ds->info->flags & GPIOEDF_PRINT_KEYS)
+			pr_info("gpio_event_input_irq_handler: key %x-%x, %d "
+				"(%d) changed to %d\n",
+				ds->info->type, key_entry->code, keymap_index,
+				key_entry->gpio, pressed);
+		input_event(ds->input_dev, ds->info->type,
+			    key_entry->code, pressed);
+	}
+	return IRQ_HANDLED;
+}
+
+static int gpio_event_input_request_irqs(struct gpio_input_state *ds)
+{
+	int i;
+	int err;
+	unsigned int irq;
+	unsigned long req_flags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
+
+	for (i = 0; i < ds->info->keymap_size; i++) {
+		err = irq = gpio_to_irq(ds->info->keymap[i].gpio);
+		if (err < 0)
+			goto err_gpio_get_irq_num_failed;
+		err = request_irq(irq, gpio_event_input_irq_handler,
+				  req_flags, "gpio_keys", &ds->key_state[i]);
+		if (err) {
+			pr_err("gpio_event_input_request_irqs: request_irq "
+				"failed for input %d, irq %d\n",
+				ds->info->keymap[i].gpio, irq);
+			goto err_request_irq_failed;
+		}
+		enable_irq_wake(irq);
+	}
+	return 0;
+
+	for (i = ds->info->keymap_size - 1; i >= 0; i--) {
+		free_irq(gpio_to_irq(ds->info->keymap[i].gpio),
+			 &ds->key_state[i]);
+err_request_irq_failed:
+err_gpio_get_irq_num_failed:
+		;
+	}
+	return err;
+}
+
+int gpio_event_input_func(struct input_dev *input_dev,
+			struct gpio_event_info *info, void **data, int func)
+{
+	int ret;
+	int i;
+	unsigned long irqflags;
+	struct gpio_event_input_info *di;
+	struct gpio_input_state *ds = *data;
+
+	di = container_of(info, struct gpio_event_input_info, info);
+
+	if (func == GPIO_EVENT_FUNC_SUSPEND) {
+		spin_lock_irqsave(&ds->irq_lock, irqflags);
+		if (ds->use_irq)
+			for (i = 0; i < di->keymap_size; i++)
+				disable_irq(gpio_to_irq(di->keymap[i].gpio));
+		spin_unlock_irqrestore(&ds->irq_lock, irqflags);
+		hrtimer_cancel(&ds->timer);
+		return 0;
+	}
+	if (func == GPIO_EVENT_FUNC_RESUME) {
+		spin_lock_irqsave(&ds->irq_lock, irqflags);
+		if (ds->use_irq)
+			for (i = 0; i < di->keymap_size; i++)
+				enable_irq(gpio_to_irq(di->keymap[i].gpio));
+		hrtimer_start(&ds->timer, ktime_set(0, 0), HRTIMER_MODE_REL);
+		spin_unlock_irqrestore(&ds->irq_lock, irqflags);
+		return 0;
+	}
+
+	if (func == GPIO_EVENT_FUNC_INIT) {
+		if (ktime_to_ns(di->poll_time) <= 0)
+			di->poll_time = ktime_set(0, 20 * NSEC_PER_MSEC);
+
+		*data = ds = kzalloc(sizeof(*ds) + sizeof(ds->key_state[0]) *
+					di->keymap_size, GFP_KERNEL);
+		if (ds == NULL) {
+			ret = -ENOMEM;
+			pr_err("gpio_event_input_func: "
+				"Failed to allocate private data\n");
+			goto err_ds_alloc_failed;
+		}
+		ds->debounce_count = di->keymap_size;
+		ds->input_dev = input_dev;
+		ds->info = di;
+		wake_lock_init(&ds->wake_lock, WAKE_LOCK_SUSPEND, "gpio_input");
+		spin_lock_init(&ds->irq_lock);
+
+		for (i = 0; i < di->keymap_size; i++) {
+			input_set_capability(input_dev, di->type,
+					     di->keymap[i].code);
+			ds->key_state[i].ds = ds;
+			ds->key_state[i].debounce = DEBOUNCE_UNKNOWN;
+		}
+
+		for (i = 0; i < di->keymap_size; i++) {
+			ret = gpio_request(di->keymap[i].gpio, "gpio_kp_in");
+			if (ret) {
+				pr_err("gpio_event_input_func: gpio_request "
+					"failed for %d\n", di->keymap[i].gpio);
+				goto err_gpio_request_failed;
+			}
+			ret = gpio_direction_input(di->keymap[i].gpio);
+			if (ret) {
+				pr_err("gpio_event_input_func: "
+					"gpio_direction_input failed for %d\n",
+					di->keymap[i].gpio);
+				goto err_gpio_configure_failed;
+			}
+		}
+
+		ret = gpio_event_input_request_irqs(ds);
+
+		spin_lock_irqsave(&ds->irq_lock, irqflags);
+		ds->use_irq = ret == 0;
+
+		pr_info("GPIO Input Driver: Start gpio inputs for %s in %s "
+			"mode\n",
+			input_dev->name, ret == 0 ? "interrupt" : "polling");
+
+		hrtimer_init(&ds->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+		ds->timer.function = gpio_event_input_timer_func;
+		hrtimer_start(&ds->timer, ktime_set(0, 0), HRTIMER_MODE_REL);
+		spin_unlock_irqrestore(&ds->irq_lock, irqflags);
+		return 0;
+	}
+
+	ret = 0;
+	spin_lock_irqsave(&ds->irq_lock, irqflags);
+	hrtimer_cancel(&ds->timer);
+	if (ds->use_irq) {
+		for (i = di->keymap_size - 1; i >= 0; i--) {
+			free_irq(gpio_to_irq(di->keymap[i].gpio),
+				 &ds->key_state[i]);
+		}
+	}
+	spin_unlock_irqrestore(&ds->irq_lock, irqflags);
+
+	for (i = di->keymap_size - 1; i >= 0; i--) {
+err_gpio_configure_failed:
+		gpio_free(di->keymap[i].gpio);
+err_gpio_request_failed:
+		;
+	}
+	wake_lock_destroy(&ds->wake_lock);
+	kfree(ds);
+err_ds_alloc_failed:
+	return ret;
+}
--- /dev/null
+++ b/drivers/input/misc/gpio_matrix.c
@@ -0,0 +1,406 @@
+/* drivers/input/misc/gpio_matrix.c
+ *
+ * Copyright (C) 2007 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/gpio.h>
+#include <linux/gpio_event.h>
+#include <linux/hrtimer.h>
+#include <linux/interrupt.h>
+#include <linux/wakelock.h>
+
+struct gpio_kp {
+	struct input_dev *input_dev;
+	struct gpio_event_matrix_info *keypad_info;
+	struct hrtimer timer;
+	struct wake_lock wake_lock;
+	int current_output;
+	unsigned int use_irq:1;
+	unsigned int key_state_changed:1;
+	unsigned int last_key_state_changed:1;
+	unsigned int some_keys_pressed:2;
+	unsigned long keys_pressed[0];
+};
+
+static void clear_phantom_key(struct gpio_kp *kp, int out, int in)
+{
+	struct gpio_event_matrix_info *mi = kp->keypad_info;
+	int key_index = out * mi->ninputs + in;
+	unsigned short keycode = mi->keymap[key_index];;
+
+	if (!test_bit(keycode, kp->input_dev->key)) {
+		if (mi->flags & GPIOKPF_PRINT_PHANTOM_KEYS)
+			pr_info("gpiomatrix: phantom key %x, %d-%d (%d-%d) "
+				"cleared\n", keycode, out, in,
+				mi->output_gpios[out], mi->input_gpios[in]);
+		__clear_bit(key_index, kp->keys_pressed);
+	} else {
+		if (mi->flags & GPIOKPF_PRINT_PHANTOM_KEYS)
+			pr_info("gpiomatrix: phantom key %x, %d-%d (%d-%d) "
+				"not cleared\n", keycode, out, in,
+				mi->output_gpios[out], mi->input_gpios[in]);
+	}
+}
+
+static int restore_keys_for_input(struct gpio_kp *kp, int out, int in)
+{
+	int rv = 0;
+	int key_index;
+
+	key_index = out * kp->keypad_info->ninputs + in;
+	while (out < kp->keypad_info->noutputs) {
+		if (test_bit(key_index, kp->keys_pressed)) {
+			rv = 1;
+			clear_phantom_key(kp, out, in);
+		}
+		key_index += kp->keypad_info->ninputs;
+		out++;
+	}
+	return rv;
+}
+
+static void remove_phantom_keys(struct gpio_kp *kp)
+{
+	int out, in, inp;
+	int key_index;
+
+	if (kp->some_keys_pressed < 3)
+		return;
+
+	for (out = 0; out < kp->keypad_info->noutputs; out++) {
+		inp = -1;
+		key_index = out * kp->keypad_info->ninputs;
+		for (in = 0; in < kp->keypad_info->ninputs; in++, key_index++) {
+			if (test_bit(key_index, kp->keys_pressed)) {
+				if (inp == -1) {
+					inp = in;
+					continue;
+				}
+				if (inp >= 0) {
+					if (!restore_keys_for_input(kp, out + 1,
+									inp))
+						break;
+					clear_phantom_key(kp, out, inp);
+					inp = -2;
+				}
+				restore_keys_for_input(kp, out, in);
+			}
+		}
+	}
+}
+
+static void report_key(struct gpio_kp *kp, int key_index, int out, int in)
+{
+	struct gpio_event_matrix_info *mi = kp->keypad_info;
+	int pressed = test_bit(key_index, kp->keys_pressed);
+	unsigned short keycode = mi->keymap[key_index];
+	if (pressed != test_bit(keycode, kp->input_dev->key)) {
+		if (keycode == KEY_RESERVED) {
+			if (mi->flags & GPIOKPF_PRINT_UNMAPPED_KEYS)
+				pr_info("gpiomatrix: unmapped key, %d-%d "
+					"(%d-%d) changed to %d\n",
+					out, in, mi->output_gpios[out],
+					mi->input_gpios[in], pressed);
+		} else {
+			if (mi->flags & GPIOKPF_PRINT_MAPPED_KEYS)
+				pr_info("gpiomatrix: key %x, %d-%d (%d-%d) "
+					"changed to %d\n", keycode,
+					out, in, mi->output_gpios[out],
+					mi->input_gpios[in], pressed);
+			input_report_key(kp->input_dev, keycode, pressed);
+		}
+	}
+}
+
+static enum hrtimer_restart gpio_keypad_timer_func(struct hrtimer *timer)
+{
+	int out, in;
+	int key_index;
+	int gpio;
+	struct gpio_kp *kp = container_of(timer, struct gpio_kp, timer);
+	struct gpio_event_matrix_info *mi = kp->keypad_info;
+	unsigned gpio_keypad_flags = mi->flags;
+	unsigned polarity = !!(gpio_keypad_flags & GPIOKPF_ACTIVE_HIGH);
+
+	out = kp->current_output;
+	if (out == mi->noutputs) {
+		out = 0;
+		kp->last_key_state_changed = kp->key_state_changed;
+		kp->key_state_changed = 0;
+		kp->some_keys_pressed = 0;
+	} else {
+		key_index = out * mi->ninputs;
+		for (in = 0; in < mi->ninputs; in++, key_index++) {
+			gpio = mi->input_gpios[in];
+			if (gpio_get_value(gpio) ^ !polarity) {
+				if (kp->some_keys_pressed < 3)
+					kp->some_keys_pressed++;
+				kp->key_state_changed |= !__test_and_set_bit(
+						key_index, kp->keys_pressed);
+			} else
+				kp->key_state_changed |= __test_and_clear_bit(
+						key_index, kp->keys_pressed);
+		}
+		gpio = mi->output_gpios[out];
+		if (gpio_keypad_flags & GPIOKPF_DRIVE_INACTIVE)
+			gpio_set_value(gpio, !polarity);
+		else
+			gpio_direction_input(gpio);
+		out++;
+	}
+	kp->current_output = out;
+	if (out < mi->noutputs) {
+		gpio = mi->output_gpios[out];
+		if (gpio_keypad_flags & GPIOKPF_DRIVE_INACTIVE)
+			gpio_set_value(gpio, polarity);
+		else
+			gpio_direction_output(gpio, polarity);
+		hrtimer_start(timer, mi->settle_time, HRTIMER_MODE_REL);
+		return HRTIMER_NORESTART;
+	}
+	if (gpio_keypad_flags & GPIOKPF_DEBOUNCE) {
+		if (kp->key_state_changed) {
+			hrtimer_start(&kp->timer, mi->debounce_delay,
+				      HRTIMER_MODE_REL);
+			return HRTIMER_NORESTART;
+		}
+		kp->key_state_changed = kp->last_key_state_changed;
+	}
+	if (kp->key_state_changed) {
+		if (gpio_keypad_flags & GPIOKPF_REMOVE_SOME_PHANTOM_KEYS)
+			remove_phantom_keys(kp);
+		key_index = 0;
+		for (out = 0; out < mi->noutputs; out++)
+			for (in = 0; in < mi->ninputs; in++, key_index++)
+				report_key(kp, key_index, out, in);
+	}
+	if (!kp->use_irq || kp->some_keys_pressed) {
+		hrtimer_start(timer, mi->poll_time, HRTIMER_MODE_REL);
+		return HRTIMER_NORESTART;
+	}
+
+	/* No keys are pressed, reenable interrupt */
+	for (out = 0; out < mi->noutputs; out++) {
+		if (gpio_keypad_flags & GPIOKPF_DRIVE_INACTIVE)
+			gpio_set_value(mi->output_gpios[out], polarity);
+		else
+			gpio_direction_output(mi->output_gpios[out], polarity);
+	}
+	for (in = 0; in < mi->ninputs; in++)
+		enable_irq(gpio_to_irq(mi->input_gpios[in]));
+	wake_unlock(&kp->wake_lock);
+	return HRTIMER_NORESTART;
+}
+
+static irqreturn_t gpio_keypad_irq_handler(int irq_in, void *dev_id)
+{
+	int i;
+	struct gpio_kp *kp = dev_id;
+	struct gpio_event_matrix_info *mi = kp->keypad_info;
+	unsigned gpio_keypad_flags = mi->flags;
+
+	if (!kp->use_irq) /* ignore interrupt while registering the handler */
+		return IRQ_HANDLED;
+
+	for (i = 0; i < mi->ninputs; i++)
+		disable_irq(gpio_to_irq(mi->input_gpios[i]));
+	for (i = 0; i < mi->noutputs; i++) {
+		if (gpio_keypad_flags & GPIOKPF_DRIVE_INACTIVE)
+			gpio_set_value(mi->output_gpios[i],
+				!(gpio_keypad_flags & GPIOKPF_ACTIVE_HIGH));
+		else
+			gpio_direction_input(mi->output_gpios[i]);
+	}
+	wake_lock(&kp->wake_lock);
+	hrtimer_start(&kp->timer, ktime_set(0, 0), HRTIMER_MODE_REL);
+	return IRQ_HANDLED;
+}
+
+static int gpio_keypad_request_irqs(struct gpio_kp *kp)
+{
+	int i;
+	int err;
+	unsigned int irq;
+	unsigned long request_flags;
+	struct gpio_event_matrix_info *mi = kp->keypad_info;
+
+	switch (mi->flags & (GPIOKPF_ACTIVE_HIGH|GPIOKPF_LEVEL_TRIGGERED_IRQ)) {
+	default:
+		request_flags = IRQF_TRIGGER_FALLING;
+		break;
+	case GPIOKPF_ACTIVE_HIGH:
+		request_flags = IRQF_TRIGGER_RISING;
+		break;
+	case GPIOKPF_LEVEL_TRIGGERED_IRQ:
+		request_flags = IRQF_TRIGGER_LOW;
+		break;
+	case GPIOKPF_LEVEL_TRIGGERED_IRQ | GPIOKPF_ACTIVE_HIGH:
+		request_flags = IRQF_TRIGGER_HIGH;
+		break;
+	}
+
+	for (i = 0; i < mi->ninputs; i++) {
+		err = irq = gpio_to_irq(mi->input_gpios[i]);
+		if (err < 0)
+			goto err_gpio_get_irq_num_failed;
+		err = request_irq(irq, gpio_keypad_irq_handler, request_flags,
+				  "gpio_kp", kp);
+		if (err) {
+			pr_err("gpiomatrix: request_irq failed for input %d, "
+				"irq %d\n", mi->input_gpios[i], irq);
+			goto err_request_irq_failed;
+		}
+		err = set_irq_wake(irq, 1);
+		if (err) {
+			pr_err("gpiomatrix: set_irq_wake failed for input %d, "
+				"irq %d\n", mi->input_gpios[i], irq);
+		}
+		disable_irq(irq);
+	}
+	return 0;
+
+	for (i = mi->noutputs - 1; i >= 0; i--) {
+		free_irq(gpio_to_irq(mi->input_gpios[i]), kp);
+err_request_irq_failed:
+err_gpio_get_irq_num_failed:
+		;
+	}
+	return err;
+}
+
+int gpio_event_matrix_func(struct input_dev *input_dev,
+	struct gpio_event_info *info, void **data, int func)
+{
+	int i;
+	int err;
+	int key_count;
+	struct gpio_kp *kp;
+	struct gpio_event_matrix_info *mi;
+
+	mi = container_of(info, struct gpio_event_matrix_info, info);
+	if (func == GPIO_EVENT_FUNC_SUSPEND || func == GPIO_EVENT_FUNC_RESUME) {
+		/* TODO: disable scanning */
+		return 0;
+	}
+
+	if (func == GPIO_EVENT_FUNC_INIT) {
+		if (mi->keymap == NULL ||
+		   mi->input_gpios == NULL ||
+		   mi->output_gpios == NULL) {
+			err = -ENODEV;
+			pr_err("gpiomatrix: Incomplete pdata\n");
+			goto err_invalid_platform_data;
+		}
+		key_count = mi->ninputs * mi->noutputs;
+
+		*data = kp = kzalloc(sizeof(*kp) + sizeof(kp->keys_pressed[0]) *
+				     BITS_TO_LONGS(key_count), GFP_KERNEL);
+		if (kp == NULL) {
+			err = -ENOMEM;
+			pr_err("gpiomatrix: Failed to allocate private data\n");
+			goto err_kp_alloc_failed;
+		}
+		kp->input_dev = input_dev;
+		kp->keypad_info = mi;
+		set_bit(EV_KEY, input_dev->evbit);
+		for (i = 0; i < key_count; i++) {
+			if (mi->keymap[i])
+				set_bit(mi->keymap[i] & KEY_MAX,
+					input_dev->keybit);
+		}
+
+		for (i = 0; i < mi->noutputs; i++) {
+			if (gpio_cansleep(mi->output_gpios[i])) {
+				pr_err("gpiomatrix: unsupported output gpio %d,"
+					" can sleep\n", mi->output_gpios[i]);
+				err = -EINVAL;
+				goto err_request_output_gpio_failed;
+			}
+			err = gpio_request(mi->output_gpios[i], "gpio_kp_out");
+			if (err) {
+				pr_err("gpiomatrix: gpio_request failed for "
+					"output %d\n", mi->output_gpios[i]);
+				goto err_request_output_gpio_failed;
+			}
+			if (mi->flags & GPIOKPF_DRIVE_INACTIVE)
+				err = gpio_direction_output(mi->output_gpios[i],
+					!(mi->flags & GPIOKPF_ACTIVE_HIGH));
+			else
+				err = gpio_direction_input(mi->output_gpios[i]);
+			if (err) {
+				pr_err("gpiomatrix: gpio_configure failed for "
+					"output %d\n", mi->output_gpios[i]);
+				goto err_output_gpio_configure_failed;
+			}
+		}
+		for (i = 0; i < mi->ninputs; i++) {
+			err = gpio_request(mi->input_gpios[i], "gpio_kp_in");
+			if (err) {
+				pr_err("gpiomatrix: gpio_request failed for "
+					"input %d\n", mi->input_gpios[i]);
+				goto err_request_input_gpio_failed;
+			}
+			err = gpio_direction_input(mi->input_gpios[i]);
+			if (err) {
+				pr_err("gpiomatrix: gpio_direction_input failed"
+					" for input %d\n", mi->input_gpios[i]);
+				goto err_gpio_direction_input_failed;
+			}
+		}
+		kp->current_output = mi->noutputs;
+		kp->key_state_changed = 1;
+
+		hrtimer_init(&kp->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+		kp->timer.function = gpio_keypad_timer_func;
+		wake_lock_init(&kp->wake_lock, WAKE_LOCK_SUSPEND, "gpio_kp");
+		err = gpio_keypad_request_irqs(kp);
+		kp->use_irq = err == 0;
+
+		pr_info("GPIO Matrix Keypad Driver: Start keypad matrix for %s "
+			"in %s mode\n", input_dev->name,
+			kp->use_irq ? "interrupt" : "polling");
+
+		if (kp->use_irq)
+			wake_lock(&kp->wake_lock);
+		hrtimer_start(&kp->timer, ktime_set(0, 0), HRTIMER_MODE_REL);
+
+		return 0;
+	}
+
+	err = 0;
+	kp = *data;
+
+	if (kp->use_irq)
+		for (i = mi->noutputs - 1; i >= 0; i--)
+			free_irq(gpio_to_irq(mi->input_gpios[i]), kp);
+
+	hrtimer_cancel(&kp->timer);
+	wake_lock_destroy(&kp->wake_lock);
+	for (i = mi->noutputs - 1; i >= 0; i--) {
+err_gpio_direction_input_failed:
+		gpio_free(mi->input_gpios[i]);
+err_request_input_gpio_failed:
+		;
+	}
+	for (i = mi->noutputs - 1; i >= 0; i--) {
+err_output_gpio_configure_failed:
+		gpio_free(mi->output_gpios[i]);
+err_request_output_gpio_failed:
+		;
+	}
+	kfree(kp);
+err_kp_alloc_failed:
+err_invalid_platform_data:
+	return err;
+}
--- /dev/null
+++ b/drivers/input/misc/gpio_output.c
@@ -0,0 +1,84 @@
+/* drivers/input/misc/gpio_output.c
+ *
+ * Copyright (C) 2007 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/gpio.h>
+#include <linux/gpio_event.h>
+
+int gpio_event_output_event(
+	struct input_dev *input_dev, struct gpio_event_info *info, void **data,
+	unsigned int type, unsigned int code, int value)
+{
+	int i;
+	struct gpio_event_output_info *oi;
+	oi = container_of(info, struct gpio_event_output_info, info);
+	if (type != oi->type)
+		return 0;
+	if (!(oi->flags & GPIOEDF_ACTIVE_HIGH))
+		value = !value;
+	for (i = 0; i < oi->keymap_size; i++)
+		if (code == oi->keymap[i].code)
+			gpio_set_value(oi->keymap[i].gpio, value);
+	return 0;
+}
+
+int gpio_event_output_func(
+	struct input_dev *input_dev, struct gpio_event_info *info, void **data,
+	int func)
+{
+	int ret;
+	int i;
+	struct gpio_event_output_info *oi;
+	oi = container_of(info, struct gpio_event_output_info, info);
+
+	if (func == GPIO_EVENT_FUNC_SUSPEND || func == GPIO_EVENT_FUNC_RESUME)
+		return 0;
+
+	if (func == GPIO_EVENT_FUNC_INIT) {
+		int output_level = !(oi->flags & GPIOEDF_ACTIVE_HIGH);
+		for (i = 0; i < oi->keymap_size; i++)
+			input_set_capability(input_dev, oi->type,
+					     oi->keymap[i].code);
+
+		for (i = 0; i < oi->keymap_size; i++) {
+			ret = gpio_request(oi->keymap[i].gpio,
+					   "gpio_event_output");
+			if (ret) {
+				pr_err("gpio_event_output_func: gpio_request "
+					"failed for %d\n", oi->keymap[i].gpio);
+				goto err_gpio_request_failed;
+			}
+			ret = gpio_direction_output(oi->keymap[i].gpio,
+						    output_level);
+			if (ret) {
+				pr_err("gpio_event_output_func: "
+					"gpio_direction_output failed for %d\n",
+					oi->keymap[i].gpio);
+				goto err_gpio_direction_output_failed;
+			}
+		}
+		return 0;
+	}
+
+	ret = 0;
+	for (i = oi->keymap_size - 1; i >= 0; i--) {
+err_gpio_direction_output_failed:
+		gpio_free(oi->keymap[i].gpio);
+err_gpio_request_failed:
+		;
+	}
+	return ret;
+}
+
--- /dev/null
+++ b/include/linux/gpio_event.h
@@ -0,0 +1,154 @@
+/* include/linux/gpio_event.h
+ *
+ * Copyright (C) 2007 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+
+#ifndef _LINUX_GPIO_EVENT_H
+#define _LINUX_GPIO_EVENT_H
+
+#include <linux/input.h>
+
+enum {
+	GPIO_EVENT_FUNC_UNINIT  = 0x0,
+	GPIO_EVENT_FUNC_INIT    = 0x1,
+	GPIO_EVENT_FUNC_SUSPEND = 0x2,
+	GPIO_EVENT_FUNC_RESUME  = 0x3,
+};
+struct gpio_event_info {
+	int (*func)(struct input_dev *input_dev,
+		    struct gpio_event_info *info,
+		    void **data, int func);
+	int (*event)(struct input_dev *input_dev,
+		     struct gpio_event_info *info,
+		     void **data, unsigned int type,
+		     unsigned int code, int value); /* out events */
+};
+
+struct gpio_event_platform_data {
+	const char *name;
+	struct gpio_event_info **info;
+	size_t info_count;
+	int (*power)(const struct gpio_event_platform_data *pdata, bool on);
+};
+
+#define GPIO_EVENT_DEV_NAME "gpio-event"
+
+/* Key matrix */
+
+enum gpio_event_matrix_flags {
+	/* unset: drive active output low, set: drive active output high */
+	GPIOKPF_ACTIVE_HIGH              = 1U << 0,
+	GPIOKPF_DEBOUNCE                 = 1U << 1,
+	GPIOKPF_REMOVE_SOME_PHANTOM_KEYS = 1U << 2,
+	GPIOKPF_REMOVE_PHANTOM_KEYS      = GPIOKPF_REMOVE_SOME_PHANTOM_KEYS |
+					   GPIOKPF_DEBOUNCE,
+	GPIOKPF_DRIVE_INACTIVE           = 1U << 3,
+	GPIOKPF_LEVEL_TRIGGERED_IRQ      = 1U << 4,
+	GPIOKPF_PRINT_UNMAPPED_KEYS      = 1U << 16,
+	GPIOKPF_PRINT_MAPPED_KEYS        = 1U << 17,
+	GPIOKPF_PRINT_PHANTOM_KEYS       = 1U << 18,
+};
+
+extern int gpio_event_matrix_func(struct input_dev *input_dev,
+			struct gpio_event_info *info, void **data, int func);
+struct gpio_event_matrix_info {
+	/* initialize to gpio_event_matrix_func */
+	struct gpio_event_info info;
+	/* size must be ninputs * noutputs */
+	const unsigned short *keymap;
+	unsigned int *input_gpios;
+	unsigned int *output_gpios;
+	unsigned int ninputs;
+	unsigned int noutputs;
+	/* time to wait before reading inputs after driving each output */
+	ktime_t settle_time;
+	/* time to wait before scanning the keypad a second time */
+	ktime_t debounce_delay;
+	ktime_t poll_time;
+	unsigned flags;
+};
+
+/* Directly connected inputs and outputs */
+
+enum gpio_event_direct_flags {
+	GPIOEDF_ACTIVE_HIGH         = 1U << 0,
+/*	GPIOEDF_USE_DOWN_IRQ        = 1U << 1, */
+/*	GPIOEDF_USE_IRQ             = (1U << 2) | GPIOIDF_USE_DOWN_IRQ, */
+	GPIOEDF_PRINT_KEYS          = 1U << 8,
+	GPIOEDF_PRINT_KEY_DEBOUNCE  = 1U << 9,
+};
+
+struct gpio_event_direct_entry {
+	uint32_t gpio:23;
+	uint32_t code:9;
+};
+
+/* inputs */
+extern int gpio_event_input_func(struct input_dev *input_dev,
+			struct gpio_event_info *info, void **data, int func);
+struct gpio_event_input_info {
+	/* initialize to gpio_event_input_func */
+	struct gpio_event_info info;
+	ktime_t debounce_time;
+	ktime_t poll_time;
+	uint16_t flags;
+	uint16_t type;
+	const struct gpio_event_direct_entry *keymap;
+	size_t keymap_size;
+};
+
+/* outputs */
+extern int gpio_event_output_func(struct input_dev *input_dev,
+			struct gpio_event_info *info, void **data, int func);
+extern int gpio_event_output_event(struct input_dev *input_dev,
+			struct gpio_event_info *info, void **data,
+			unsigned int type, unsigned int code, int value);
+struct gpio_event_output_info {
+	/* initialize to gpio_event_output_func and gpio_event_output_event */
+	struct gpio_event_info info;
+	uint16_t flags;
+	uint16_t type;
+	const struct gpio_event_direct_entry *keymap;
+	size_t keymap_size;
+};
+
+
+/* axes */
+
+enum gpio_event_axis_flags {
+	GPIOEAF_PRINT_UNKNOWN_DIRECTION  = 1U << 16,
+	GPIOEAF_PRINT_RAW                = 1U << 17,
+	GPIOEAF_PRINT_EVENT              = 1U << 18,
+};
+
+extern int gpio_event_axis_func(struct input_dev *input_dev,
+			struct gpio_event_info *info, void **data, int func);
+struct gpio_event_axis_info {
+	/* initialize to gpio_event_axis_func */
+	struct gpio_event_info info;
+	uint8_t  count;
+	uint8_t  type; /* EV_REL or EV_ABS */
+	uint16_t code;
+	uint16_t decoded_size;
+	uint16_t (*map)(struct gpio_event_axis_info *info, uint16_t in);
+	uint32_t *gpio;
+	uint32_t flags;
+};
+#define gpio_axis_2bit_gray_map gpio_axis_4bit_gray_map
+#define gpio_axis_3bit_gray_map gpio_axis_4bit_gray_map
+uint16_t gpio_axis_4bit_gray_map(
+			struct gpio_event_axis_info *info, uint16_t in);
+uint16_t gpio_axis_5bit_singletrack_map(
+			struct gpio_event_axis_info *info, uint16_t in);
+
+#endif
