text: /*
   * Driver for keys on GPIO lines capable of generating interrupts.
   *
   * Copyright 2005 Phil Blundell
   * Copyright 2010, 2011 David Jander <david@protonic.nl>
   *
   * 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/module.h>
  
  #include <linux/init.h>
  #include <linux/fs.h>
  #include <linux/interrupt.h>
  #include <linux/irq.h>
  #include <linux/sched.h>
  #include <linux/pm.h>
  #include <linux/slab.h>
  #include <linux/sysctl.h>
  #include <linux/proc_fs.h>
  #include <linux/delay.h>
  #include <linux/platform_device.h>
  #include <linux/input.h>
  #include <linux/gpio_keys.h>
  #include <linux/workqueue.h>
  #include <linux/gpio.h>
  #include <linux/gpio/consumer.h>
  #include <linux/of.h>
  #include <linux/of_irq.h>
  #include <linux/spinlock.h>
  
  #if defined(CONFIG_DT_SF16A18_FULLMASK_86V) || defined(CONFIG_DT_SF16A18_FULLMASK_86V_C2)
  #include <linux/uaccess.h>
  #include <linux/reboot.h>
  #define REBOOT_BUTTON (26)
  #define REBOOT_PRESS_SLOT (5)
  #endif
  struct gpio_button_data {
  	const struct gpio_keys_button *button;
  	struct input_dev *input;
  	struct gpio_desc *gpiod;
  
  	unsigned short *code;
  
  	struct timer_list release_timer;
  	unsigned int release_delay;	/* in msecs, for IRQ-only buttons */
  
  	struct delayed_work work;
  	unsigned int software_debounce;	/* in msecs, for GPIO-driven buttons */
  
  	unsigned int irq;
  #if defined(CONFIG_DT_SF16A18_FULLMASK_86V) || defined(CONFIG_DT_SF16A18_FULLMASK_86V_C2)
  	unsigned long last_seen;
  #endif
  	spinlock_t lock;
  	bool disabled;
  	bool key_pressed;
  	bool suspended;
  };
  
  struct gpio_keys_drvdata {
  	const struct gpio_keys_platform_data *pdata;
  	struct input_dev *input;
  	struct mutex disable_lock;
  	unsigned short *keymap;
  	struct gpio_button_data data[0];
  };
  #if defined(CONFIG_DT_SF16A18_FULLMASK_86V) || defined(CONFIG_DT_SF16A18_FULLMASK_86V_C2)
  static int gpio_mode_sel;
  #endif
  /*
   * SYSFS interface for enabling/disabling keys and switches:
   *
   * There are 4 attributes under /sys/devices/platform/gpio-keys/
   *	keys [ro]              - bitmap of keys (EV_KEY) which can be
   *	                         disabled
   *	switches [ro]          - bitmap of switches (EV_SW) which can be
   *	                         disabled
   *	disabled_keys [rw]     - bitmap of keys currently disabled
   *	disabled_switches [rw] - bitmap of switches currently disabled
   *
   * Userland can change these values and hence disable event generation
   * for each key (or switch). Disabling a key means its interrupt line
   * is disabled.
   *
   * For example, if we have following switches set up as gpio-keys:
   *	SW_DOCK = 5
   *	SW_CAMERA_LENS_COVER = 9
   *	SW_KEYPAD_SLIDE = 10
   *	SW_FRONT_PROXIMITY = 11
   * This is read from switches:
   *	11-9,5
   * Next we want to disable proximity (11) and dock (5), we write:
   *	11,5
   * to file disabled_switches. Now proximity and dock IRQs are disabled.
   * This can be verified by reading the file disabled_switches:
   *	11,5
   * If we now want to enable proximity (11) switch we write:
   *	5
   * to disabled_switches.
   *
   * We can disable only those keys which don't allow sharing the irq.
   */
  
  /**
   * get_n_events_by_type() - returns maximum number of events per @type
   * @type: type of button (%EV_KEY, %EV_SW)
   *
   * Return value of this function can be used to allocate bitmap
   * large enough to hold all bits for given type.
   */
  static int get_n_events_by_type(int type)
  {
  	BUG_ON(type != EV_SW && type != EV_KEY);
  
  	return (type == EV_KEY) ? KEY_CNT : SW_CNT;
  }
  
  /**
   * get_bm_events_by_type() - returns bitmap of supported events per @type
   * @input: input device from which bitmap is retrieved
   * @type: type of button (%EV_KEY, %EV_SW)
   *
   * Return value of this function can be used to allocate bitmap
   * large enough to hold all bits for given type.
   */
  static const unsigned long *get_bm_events_by_type(struct input_dev *dev,
  						  int type)
  {
  	BUG_ON(type != EV_SW && type != EV_KEY);
  
  	return (type == EV_KEY) ? dev->keybit : dev->swbit;
  }
  
  /**
   * gpio_keys_disable_button() - disables given GPIO button
   * @bdata: button data for button to be disabled
   *
   * Disables button pointed by @bdata. This is done by masking
   * IRQ line. After this function is called, button won't generate
   * input events anymore. Note that one can only disable buttons
   * that don't share IRQs.
   *
   * Make sure that @bdata->disable_lock is locked when entering
   * this function to avoid races when concurrent threads are
   * disabling buttons at the same time.
   */
  static void gpio_keys_disable_button(struct gpio_button_data *bdata)
  {
  	if (!bdata->disabled) {
  		/*
  		 * Disable IRQ and associated timer/work structure.
  		 */
  		disable_irq(bdata->irq);
  
  		if (bdata->gpiod)
  			cancel_delayed_work_sync(&bdata->work);
  		else
  			del_timer_sync(&bdata->release_timer);
  
  		bdata->disabled = true;
  	}
  }
  
  /**
   * gpio_keys_enable_button() - enables given GPIO button
   * @bdata: button data for button to be disabled
   *
   * Enables given button pointed by @bdata.
   *
   * Make sure that @bdata->disable_lock is locked when entering
   * this function to avoid races with concurrent threads trying
   * to enable the same button at the same time.
   */
  static void gpio_keys_enable_button(struct gpio_button_data *bdata)
  {
  	if (bdata->disabled) {
  		enable_irq(bdata->irq);
  		bdata->disabled = false;
  	}
  }
  
  /**
   * gpio_keys_attr_show_helper() - fill in stringified bitmap of buttons
   * @ddata: pointer to drvdata
   * @buf: buffer where stringified bitmap is written
   * @type: button type (%EV_KEY, %EV_SW)
   * @only_disabled: does caller want only those buttons that are
   *                 currently disabled or all buttons that can be
   *                 disabled
   *
   * This function writes buttons that can be disabled to @buf. If
   * @only_disabled is true, then @buf contains only those buttons
   * that are currently disabled. Returns 0 on success or negative
   * errno on failure.
   */
  static ssize_t gpio_keys_attr_show_helper(struct gpio_keys_drvdata *ddata,
  					  char *buf, unsigned int type,
  					  bool only_disabled)
  {
  	int n_events = get_n_events_by_type(type);
  	unsigned long *bits;
  	ssize_t ret;
  	int i;
  
  	bits = kcalloc(BITS_TO_LONGS(n_events), sizeof(*bits), GFP_KERNEL);
  	if (!bits)
  		return -ENOMEM;
  
  	for (i = 0; i < ddata->pdata->nbuttons; i++) {
  		struct gpio_button_data *bdata = &ddata->data[i];
  
  		if (bdata->button->type != type)
  			continue;
  
  		if (only_disabled && !bdata->disabled)
  			continue;
  
  		__set_bit(*bdata->code, bits);
  	}
  
  	ret = scnprintf(buf, PAGE_SIZE - 1, "%*pbl", n_events, bits);
  	buf[ret++] = '\n';
  	buf[ret] = '\0';
  
  	kfree(bits);
  
  	return ret;
  }
  
  /**
   * gpio_keys_attr_store_helper() - enable/disable buttons based on given bitmap
   * @ddata: pointer to drvdata
   * @buf: buffer from userspace that contains stringified bitmap
   * @type: button type (%EV_KEY, %EV_SW)
   *
   * This function parses stringified bitmap from @buf and disables/enables
   * GPIO buttons accordingly. Returns 0 on success and negative error
   * on failure.
   */
  static ssize_t gpio_keys_attr_store_helper(struct gpio_keys_drvdata *ddata,
  					   const char *buf, unsigned int type)
  {
  	int n_events = get_n_events_by_type(type);
  	const unsigned long *bitmap = get_bm_events_by_type(ddata->input, type);
  	unsigned long *bits;
  	ssize_t error;
  	int i;
  
  	bits = kcalloc(BITS_TO_LONGS(n_events), sizeof(*bits), GFP_KERNEL);
  	if (!bits)
  		return -ENOMEM;
  
  	error = bitmap_parselist(buf, bits, n_events);
  	if (error)
  		goto out;
  
  	/* First validate */
  	if (!bitmap_subset(bits, bitmap, n_events)) {
  		error = -EINVAL;
  		goto out;
  	}
  
  	for (i = 0; i < ddata->pdata->nbuttons; i++) {
  		struct gpio_button_data *bdata = &ddata->data[i];
  
  		if (bdata->button->type != type)
  			continue;
  
  		if (test_bit(*bdata->code, bits) &&
  		    !bdata->button->can_disable) {
  			error = -EINVAL;
  			goto out;
  		}
  	}
  
  	mutex_lock(&ddata->disable_lock);
  
  	for (i = 0; i < ddata->pdata->nbuttons; i++) {
  		struct gpio_button_data *bdata = &ddata->data[i];
  
  		if (bdata->button->type != type)
  			continue;
  
  		if (test_bit(*bdata->code, bits))
  			gpio_keys_disable_button(bdata);
  		else
  			gpio_keys_enable_button(bdata);
  	}
  
  	mutex_unlock(&ddata->disable_lock);
  
  out:
  	kfree(bits);
  	return error;
  }
  
  #define ATTR_SHOW_FN(name, type, only_disabled)				\
  static ssize_t gpio_keys_show_##name(struct device *dev,		\
  				     struct device_attribute *attr,	\
  				     char *buf)				\
  {									\
  	struct platform_device *pdev = to_platform_device(dev);		\
  	struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);	\
  									\
  	return gpio_keys_attr_show_helper(ddata, buf,			\
  					  type, only_disabled);		\
  }
  
  ATTR_SHOW_FN(keys, EV_KEY, false);
  ATTR_SHOW_FN(switches, EV_SW, false);
  ATTR_SHOW_FN(disabled_keys, EV_KEY, true);
  ATTR_SHOW_FN(disabled_switches, EV_SW, true);
  
  /*
   * ATTRIBUTES:
   *
   * /sys/devices/platform/gpio-keys/keys [ro]
   * /sys/devices/platform/gpio-keys/switches [ro]
   */
  static DEVICE_ATTR(keys, S_IRUGO, gpio_keys_show_keys, NULL);
  static DEVICE_ATTR(switches, S_IRUGO, gpio_keys_show_switches, NULL);
  
  #define ATTR_STORE_FN(name, type)					\
  static ssize_t gpio_keys_store_##name(struct device *dev,		\
  				      struct device_attribute *attr,	\
  				      const char *buf,			\
  				      size_t count)			\
  {									\
  	struct platform_device *pdev = to_platform_device(dev);		\
  	struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);	\
  	ssize_t error;							\
  									\
  	error = gpio_keys_attr_store_helper(ddata, buf, type);		\
  	if (error)							\
  		return error;						\
  									\
  	return count;							\
  }
  
  ATTR_STORE_FN(disabled_keys, EV_KEY);
  ATTR_STORE_FN(disabled_switches, EV_SW);
  
  /*
   * ATTRIBUTES:
   *
   * /sys/devices/platform/gpio-keys/disabled_keys [rw]
   * /sys/devices/platform/gpio-keys/disables_switches [rw]
   */
  static DEVICE_ATTR(disabled_keys, S_IWUSR | S_IRUGO,
  		   gpio_keys_show_disabled_keys,
  		   gpio_keys_store_disabled_keys);
  static DEVICE_ATTR(disabled_switches, S_IWUSR | S_IRUGO,
  		   gpio_keys_show_disabled_switches,
  		   gpio_keys_store_disabled_switches);
  
  static struct attribute *gpio_keys_attrs[] = {
  	&dev_attr_keys.attr,
  	&dev_attr_switches.attr,
  	&dev_attr_disabled_keys.attr,
  	&dev_attr_disabled_switches.attr,
  	NULL,
  };
  
  static const struct attribute_group gpio_keys_attr_group = {
  	.attrs = gpio_keys_attrs,
  };
  
  static void gpio_keys_gpio_report_event(struct gpio_button_data *bdata)
  {
  	const struct gpio_keys_button *button = bdata->button;
  	struct input_dev *input = bdata->input;
  	unsigned int type = button->type ?: EV_KEY;
  	int state;
  
  	state = gpiod_get_value_cansleep(bdata->gpiod);
  	if (state < 0) {
  		dev_err(input->dev.parent,
  			"failed to get gpio state: %d\n", state);
  		return;
  	}
  
  	if (type == EV_ABS) {
  		if (state)
  			input_event(input, type, button->code, button->value);
  	} else {
  		input_event(input, type, *bdata->code, state);
  	}
  	input_sync(input);
  }
  
  static void gpio_keys_gpio_work_func(struct work_struct *work)
  {
  	struct gpio_button_data *bdata =
  		container_of(work, struct gpio_button_data, work.work);
  #if defined(CONFIG_DT_SF16A18_FULLMASK_86V) || defined(CONFIG_DT_SF16A18_FULLMASK_86V_C2)
  	const struct gpio_keys_button *button = bdata->button;
  	int state = (gpio_get_value_cansleep(button->gpio) ? 1 : 0) ^ button->active_low;
  
  	if (button->gpio == REBOOT_BUTTON) {
  		if (bdata->last_seen && (jiffies - bdata->last_seen) / 100 >= REBOOT_PRESS_SLOT && state)
  			machine_restart(NULL);
  		bdata->last_seen = jiffies;
  	}
  #endif
  
  	gpio_keys_gpio_report_event(bdata);
  
  	if (bdata->button->wakeup)
  		pm_relax(bdata->input->dev.parent);
  }
  
  static irqreturn_t gpio_keys_gpio_isr(int irq, void *dev_id)
  {
  	struct gpio_button_data *bdata = dev_id;
  
  	BUG_ON(irq != bdata->irq);
  
  	if (bdata->button->wakeup) {
  		const struct gpio_keys_button *button = bdata->button;
  
  		pm_stay_awake(bdata->input->dev.parent);
  		if (bdata->suspended  &&
  		    (button->type == 0 || button->type == EV_KEY)) {
  			/*
  			 * Simulate wakeup key press in case the key has
  			 * already released by the time we got interrupt
  			 * handler to run.
  			 */
  			input_report_key(bdata->input, button->code, 1);
  		}
  	}
  
  	mod_delayed_work(system_wq,
  			 &bdata->work,
  			 msecs_to_jiffies(bdata->software_debounce));
  
  	return IRQ_HANDLED;
  }
  
  static void gpio_keys_irq_timer(unsigned long _data)
  {
  	struct gpio_button_data *bdata = (struct gpio_button_data *)_data;
  	struct input_dev *input = bdata->input;
  	unsigned long flags;
  
  	spin_lock_irqsave(&bdata->lock, flags);
  	if (bdata->key_pressed) {
  		input_event(input, EV_KEY, *bdata->code, 0);
  		input_sync(input);
  		bdata->key_pressed = false;
  	}
  	spin_unlock_irqrestore(&bdata->lock, flags);
  }
  
  static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id)
  {
  	struct gpio_button_data *bdata = dev_id;
  	struct input_dev *input = bdata->input;
  	unsigned long flags;
  
  	BUG_ON(irq != bdata->irq);
  
  	spin_lock_irqsave(&bdata->lock, flags);
  
  	if (!bdata->key_pressed) {
  		if (bdata->button->wakeup)
  			pm_wakeup_event(bdata->input->dev.parent, 0);
  
  		input_event(input, EV_KEY, *bdata->code, 1);
  		input_sync(input);
  
  		if (!bdata->release_delay) {
  			input_event(input, EV_KEY, *bdata->code, 0);
  			input_sync(input);
  			goto out;
  		}
  
  		bdata->key_pressed = true;
  	}
  
  	if (bdata->release_delay)
  		mod_timer(&bdata->release_timer,
  			jiffies + msecs_to_jiffies(bdata->release_delay));
  out:
  	spin_unlock_irqrestore(&bdata->lock, flags);
  	return IRQ_HANDLED;
  }
  
  static void gpio_keys_quiesce_key(void *data)
  {
  	struct gpio_button_data *bdata = data;
  
  	if (bdata->gpiod)
  		cancel_delayed_work_sync(&bdata->work);
  	else
  		del_timer_sync(&bdata->release_timer);
  }
  
  static int gpio_keys_setup_key(struct platform_device *pdev,
  				struct input_dev *input,
  				struct gpio_keys_drvdata *ddata,
  				const struct gpio_keys_button *button,
  				int idx,
  				struct fwnode_handle *child)
  {
  	const char *desc = button->desc ? button->desc : "gpio_keys";
  	struct device *dev = &pdev->dev;
  	struct gpio_button_data *bdata = &ddata->data[idx];
  	irq_handler_t isr;
  	unsigned long irqflags;
  	int irq;
  	int error;
  
  	bdata->input = input;
  	bdata->button = button;
  	spin_lock_init(&bdata->lock);
  
  	if (child) {
  		bdata->gpiod = devm_fwnode_get_gpiod_from_child(dev, NULL,
  								child,
  								GPIOD_IN,
  								desc);
  		if (IS_ERR(bdata->gpiod)) {
  			error = PTR_ERR(bdata->gpiod);
  			if (error == -ENOENT) {
  				/*
  				 * GPIO is optional, we may be dealing with
  				 * purely interrupt-driven setup.
  				 */
  				bdata->gpiod = NULL;
  			} else {
  				if (error != -EPROBE_DEFER)
  					dev_err(dev, "failed to get gpio: %d\n",
  						error);
  				return error;
  			}
  		}
  	} else if (gpio_is_valid(button->gpio)) {
  		/*
  		 * Legacy GPIO number, so request the GPIO here and
  		 * convert it to descriptor.
  		 */
  		unsigned flags = GPIOF_IN;
  
  		if (button->active_low)
  			flags |= GPIOF_ACTIVE_LOW;
  
  		error = devm_gpio_request_one(dev, button->gpio, flags, desc);
  		if (error < 0) {
  			dev_err(dev, "Failed to request GPIO %d, error %d\n",
  				button->gpio, error);
  			return error;
  		}
  
  		bdata->gpiod = gpio_to_desc(button->gpio);
  		if (!bdata->gpiod)
  			return -EINVAL;
  	}
  
  	if (bdata->gpiod) {
  		if (button->debounce_interval) {
  			error = gpiod_set_debounce(bdata->gpiod,
  					button->debounce_interval * 1000);
  			/* use timer if gpiolib doesn't provide debounce */
  			if (error < 0)
  				bdata->software_debounce =
  						button->debounce_interval;
  		}
  
  		if (button->irq) {
  			bdata->irq = button->irq;
  		} else {
  			irq = gpiod_to_irq(bdata->gpiod);
  			if (irq < 0) {
  				error = irq;
  				dev_err(dev,
  					"Unable to get irq number for GPIO %d, error %d\n",
  					button->gpio, error);
  				return error;
  			}
  			bdata->irq = irq;
  		}
  
  		INIT_DELAYED_WORK(&bdata->work, gpio_keys_gpio_work_func);
  
  		isr = gpio_keys_gpio_isr;
  		irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
  
  	} else {
  		if (!button->irq) {
  			dev_err(dev, "Found button without gpio or irq\n");
  			return -EINVAL;
  		}
  
  		bdata->irq = button->irq;
  
  		if (button->type && button->type != EV_KEY) {
  			dev_err(dev, "Only EV_KEY allowed for IRQ buttons.\n");
  			return -EINVAL;
  		}
  
  		bdata->release_delay = button->debounce_interval;
  		setup_timer(&bdata->release_timer,
  			    gpio_keys_irq_timer, (unsigned long)bdata);
  
  		isr = gpio_keys_irq_isr;
  		irqflags = 0;
  	}
  
  	bdata->code = &ddata->keymap[idx];
  	*bdata->code = button->code;
  	input_set_capability(input, button->type ?: EV_KEY, *bdata->code);
  
  	/*
  	 * Install custom action to cancel release timer and
  	 * workqueue item.
  	 */
  	error = devm_add_action(dev, gpio_keys_quiesce_key, bdata);
  	if (error) {
  		dev_err(dev, "failed to register quiesce action, error: %d\n",
  			error);
  		return error;
  	}
  
  	/*
  	 * If platform has specified that the button can be disabled,
  	 * we don't want it to share the interrupt line.
  	 */
  	if (!button->can_disable)
  		irqflags |= IRQF_SHARED;
  
  	error = devm_request_any_context_irq(dev, bdata->irq, isr, irqflags,
  					     desc, bdata);
  	if (error < 0) {
  		dev_err(dev, "Unable to claim irq %d; error %d\n",
  			bdata->irq, error);
  		return error;
  	}
  
  	return 0;
  }
  
  static void gpio_keys_report_state(struct gpio_keys_drvdata *ddata)
  {
  	struct input_dev *input = ddata->input;
  	int i;
  
  	for (i = 0; i < ddata->pdata->nbuttons; i++) {
  		struct gpio_button_data *bdata = &ddata->data[i];
  		if (bdata->gpiod)
  			gpio_keys_gpio_report_event(bdata);
  	}
  	input_sync(input);
  }
  
  static int gpio_keys_open(struct input_dev *input)
  {
  	struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
  	const struct gpio_keys_platform_data *pdata = ddata->pdata;
  	int error;
  
  	if (pdata->enable) {
  		error = pdata->enable(input->dev.parent);
  		if (error)
  			return error;
  	}
  
  	/* Report current state of buttons that are connected to GPIOs */
  	gpio_keys_report_state(ddata);
  
  	return 0;
  }
  
  static void gpio_keys_close(struct input_dev *input)
  {
  	struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
  	const struct gpio_keys_platform_data *pdata = ddata->pdata;
  
  	if (pdata->disable)
  		pdata->disable(input->dev.parent);
  }
  
  /*
   * Handlers for alternative sources of platform_data
   */
  
  /*
   * Translate properties into platform_data
   */
  static struct gpio_keys_platform_data *
  gpio_keys_get_devtree_pdata(struct device *dev)
  {
  	struct gpio_keys_platform_data *pdata;
  	struct gpio_keys_button *button;
  	struct fwnode_handle *child;
  	int nbuttons;
  
  	nbuttons = device_get_child_node_count(dev);
  	if (nbuttons == 0)
  		return ERR_PTR(-ENODEV);
  
  	pdata = devm_kzalloc(dev,
  			     sizeof(*pdata) + nbuttons * sizeof(*button),
  			     GFP_KERNEL);
  	if (!pdata)
  		return ERR_PTR(-ENOMEM);
  
  	button = (struct gpio_keys_button *)(pdata + 1);
  
  	pdata->buttons = button;
  	pdata->nbuttons = nbuttons;
  
  	pdata->rep = device_property_read_bool(dev, "autorepeat");
  
  	device_property_read_string(dev, "label", &pdata->name);
  
  	device_for_each_child_node(dev, child) {
  		if (is_of_node(child))
  			button->irq =
  				irq_of_parse_and_map(to_of_node(child), 0);
  
  		if (fwnode_property_read_u32(child, "linux,code",
  					     &button->code)) {
  			dev_err(dev, "Button without keycode\n");
  			fwnode_handle_put(child);
  			return ERR_PTR(-EINVAL);
  		}
  
  		fwnode_property_read_string(child, "label", &button->desc);
  
  		if (fwnode_property_read_u32(child, "linux,input-type",
  					     &button->type))
  			button->type = EV_KEY;
  
  		button->wakeup =
  			fwnode_property_read_bool(child, "wakeup-source") ||
  			/* legacy name */
  			fwnode_property_read_bool(child, "gpio-key,wakeup");
  
  		button->can_disable =
  			fwnode_property_read_bool(child, "linux,can-disable");
  
  		if (fwnode_property_read_u32(child, "debounce-interval",
  					 &button->debounce_interval))
  			button->debounce_interval = 5;
  
  		button++;
  	}
  
  	return pdata;
  }
  
  static const struct of_device_id gpio_keys_of_match[] = {
  	{ .compatible = "gpio-keys", },
  	{ },
  };
  MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
  #if defined(CONFIG_DT_SF16A18_FULLMASK_86V) || defined(CONFIG_DT_SF16A18_FULLMASK_86V_C2)
  int sfax8_mode_value(void)
  {
  	return gpio_get_value_cansleep(gpio_mode_sel);
  }
  EXPORT_SYMBOL(sfax8_mode_value);
  
  static int sfax8_mode_show(struct seq_file *m, void *v)
  {
  	return 0;
  }
  
  static int sfax8_mode_open(struct inode *inode, struct file *file)
  {
  	return single_open(file, sfax8_mode_show, PDE_DATA(inode));
  }
  
  //get the value of the gpio_key
  static ssize_t sfax8_mode_read(struct file *file, char __user *buffer,
  							size_t count, loff_t *f_ops)
  {
  	char useage[] = "0\n";
  	char high_bak[] = "1\n";
  	int ret;
  	if( *f_ops > 0)
  		return 0;
  
  	if(sfax8_mode_value()==1)
  		strcpy(useage, high_bak);
  
  	ret = sizeof(useage);
  	if(copy_to_user(buffer, useage, ret))
  		ret = -EFAULT;
  	else
  		*f_ops += ret;
  	return ret;
  }
  
  static struct file_operations sfax8_mode_ops = {
  	.owner		= THIS_MODULE,
  	.open		= sfax8_mode_open,
  	.read		= sfax8_mode_read,
  	.release	= single_release,
  	.llseek		= seq_lseek,
  };
  #endif
  
  
  static int gpio_keys_probe(struct platform_device *pdev)
  {
  	struct device *dev = &pdev->dev;
  	const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
  	struct fwnode_handle *child = NULL;
  	struct gpio_keys_drvdata *ddata;
  	struct input_dev *input;
  	size_t size;
  	int i, error;
  	int wakeup = 0;
  #if defined(CONFIG_DT_SF16A18_FULLMASK_86V) || defined(CONFIG_DT_SF16A18_FULLMASK_86V_C2)
  	struct proc_dir_entry *file;
  	const struct gpio_keys_button *button_sel;
  #endif
  
  	if (!pdata) {
  		pdata = gpio_keys_get_devtree_pdata(dev);
  		if (IS_ERR(pdata))
  			return PTR_ERR(pdata);
  	}
  
  	size = sizeof(struct gpio_keys_drvdata) +
  			pdata->nbuttons * sizeof(struct gpio_button_data);
  	ddata = devm_kzalloc(dev, size, GFP_KERNEL);
  	if (!ddata) {
  		dev_err(dev, "failed to allocate state\n");
  		return -ENOMEM;
  	}
  
  	ddata->keymap = devm_kcalloc(dev,
  				     pdata->nbuttons, sizeof(ddata->keymap[0]),
  				     GFP_KERNEL);
  	if (!ddata->keymap)
  		return -ENOMEM;
  
  	input = devm_input_allocate_device(dev);
  	if (!input) {
  		dev_err(dev, "failed to allocate input device\n");
  		return -ENOMEM;
  	}
  
  	ddata->pdata = pdata;
  	ddata->input = input;
  	mutex_init(&ddata->disable_lock);
  
  	platform_set_drvdata(pdev, ddata);
  	input_set_drvdata(input, ddata);
  
  	input->name = pdata->name ? : pdev->name;
  	input->phys = "gpio-keys/input0";
  	input->dev.parent = dev;
  	input->open = gpio_keys_open;
  	input->close = gpio_keys_close;
  
  	input->id.bustype = BUS_HOST;
  	input->id.vendor = 0x0001;
  	input->id.product = 0x0001;
  	input->id.version = 0x0100;
  
  	input->keycode = ddata->keymap;
  	input->keycodesize = sizeof(ddata->keymap[0]);
  	input->keycodemax = pdata->nbuttons;
  
  	/* Enable auto repeat feature of Linux input subsystem */
  	if (pdata->rep)
  		__set_bit(EV_REP, input->evbit);
  
  	for (i = 0; i < pdata->nbuttons; i++) {
  		const struct gpio_keys_button *button = &pdata->buttons[i];
  
  		if (!dev_get_platdata(dev)) {
  			child = device_get_next_child_node(dev, child);
  			if (!child) {
  				dev_err(dev,
  					"missing child device node for entry %d\n",
  					i);
  				return -EINVAL;
  			}
  		}
  
  		error = gpio_keys_setup_key(pdev, input, ddata,
  					    button, i, child);
  		if (error) {
  			fwnode_handle_put(child);
  			return error;
  		}
  
  		if (button->wakeup)
  			wakeup = 1;
  	}
  
  #if defined(CONFIG_DT_SF16A18_FULLMASK_86V) || defined(CONFIG_DT_SF16A18_FULLMASK_86V_C2)
  	button_sel = &pdata->buttons[0];
  	gpio_mode_sel = button_sel->gpio;
  
  	file = proc_create_data("sfax8_mode_info", 0644, NULL, &sfax8_mode_ops, NULL);
  	if (!file) {
  		dev_err(dev, "Creat sfax8_mode_info node failed\n");
  		return -ENOMEM;
  	}
  #endif
  
  	fwnode_handle_put(child);
  
  	error = devm_device_add_group(dev, &gpio_keys_attr_group);
  	if (error) {
  		dev_err(dev, "Unable to export keys/switches, error: %d\n",
  			error);
  		return error;
  	}
  
  	error = input_register_device(input);
  	if (error) {
  		dev_err(dev, "Unable to register input device, error: %d\n",
  			error);
  		return error;
  	}
  
  	device_init_wakeup(dev, wakeup);
  
  	return 0;
  }
  
  static int __maybe_unused gpio_keys_suspend(struct device *dev)
  {
  	struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
  	struct input_dev *input = ddata->input;
  	int i;
  
  	if (device_may_wakeup(dev)) {
  		for (i = 0; i < ddata->pdata->nbuttons; i++) {
  			struct gpio_button_data *bdata = &ddata->data[i];
  			if (bdata->button->wakeup)
  				enable_irq_wake(bdata->irq);
  			bdata->suspended = true;
  		}
  	} else {
  		mutex_lock(&input->mutex);
  		if (input->users)
  			gpio_keys_close(input);
  		mutex_unlock(&input->mutex);
  	}
  
  	return 0;
  }
  
  static int __maybe_unused gpio_keys_resume(struct device *dev)
  {
  	struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
  	struct input_dev *input = ddata->input;
  	int error = 0;
  	int i;
  
  	if (device_may_wakeup(dev)) {
  		for (i = 0; i < ddata->pdata->nbuttons; i++) {
  			struct gpio_button_data *bdata = &ddata->data[i];
  			if (bdata->button->wakeup)
  				disable_irq_wake(bdata->irq);
  			bdata->suspended = false;
  		}
  	} else {
  		mutex_lock(&input->mutex);
  		if (input->users)
  			error = gpio_keys_open(input);
  		mutex_unlock(&input->mutex);
  	}
  
  	if (error)
  		return error;
  
  	gpio_keys_report_state(ddata);
  	return 0;
  }
  
  static SIMPLE_DEV_PM_OPS(gpio_keys_pm_ops, gpio_keys_suspend, gpio_keys_resume);
  
  static struct platform_driver gpio_keys_device_driver = {
  	.probe		= gpio_keys_probe,
  	.driver		= {
  		.name	= "gpio-keys",
  		.pm	= &gpio_keys_pm_ops,
  		.of_match_table = gpio_keys_of_match,
  	}
  };
  
  static int __init gpio_keys_init(void)
  {
  	return platform_driver_register(&gpio_keys_device_driver);
  }
  
  static void __exit gpio_keys_exit(void)
  {
  	platform_driver_unregister(&gpio_keys_device_driver);
  }
  
  late_initcall(gpio_keys_init);
  module_exit(gpio_keys_exit);
  
  MODULE_LICENSE("GPL");
  MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
  MODULE_DESCRIPTION("Keyboard driver for GPIOs");
  MODULE_ALIAS("platform:gpio-keys");
  