Staging: dream: add support for input on GPIO pins

Support for input devices connected to GPIO pins. This adds support
for HTC Dream's keyboard and its trackball. Generic support already
exists for keyboard on GPIO, but this one is more advanced because it
can detect shadow key presses (and actually works with Dream :-).

(It also contains Kconfig/Makefile changes, including some that were
missing from previous commit. Sorry.)
Signed-off-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/dream/Kconfig

+source "drivers/staging/dream/smd/Kconfig"
+
+source "drivers/staging/dream/camera/Kconfig"
+
+
+config INPUT_GPIO
+	tristate "GPIO driver support"
+	help
+	  Say Y here if you want to support gpio based keys, wheels etc...
+
+
+

drivers/staging/dream/Makefile

+obj-$(CONFIG_MSM_ADSP)		+= qdsp5/ smd/
+obj-$(CONFIG_MSM_CAMERA)	+= camera/
+obj-$(CONFIG_INPUT_GPIO)	+= gpio_axis.o gpio_event.o gpio_input.o gpio_matrix.o gpio_output.o
+

drivers/staging/dream/gpio_axis.c

+/* 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;
+}

drivers/staging/dream/gpio_event.c

+/* 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");
+

drivers/staging/dream/gpio_input.c

+/* 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;
+}

drivers/staging/dream/gpio_matrix.c

+/* 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;
+}

drivers/staging/dream/gpio_output.c

+/* 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;
+}
+