/*----------------------------------------------------------------------------*/

/*
 * SARADC dual-joystick gamepad driver
 */

/*----------------------------------------------------------------------------*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/input-polldev.h>
#include <linux/ioport.h>
#include <linux/platform_device.h>
#include <linux/gpio.h>
#include <linux/gpio/consumer.h>
#include <linux/gpio_keys.h>
#include <linux/iio/consumer.h>
#include <linux/iio/types.h>
#include <linux/property.h>
#include <linux/of_gpio.h>
#include <linux/delay.h>
#include <linux/pwm.h>

/*----------------------------------------------------------------------------*/
#define DRV_NAME "retrogame_joypad"

/*----------------------------------------------------------------------------*/
#define	ADC_MAX_VOLTAGE		1800
#define	ADC_DATA_TUNING(x, p)	((x * p) / 100)
#define	ADC_TUNING_DEFAULT	180
#define	CLAMP(x, low, high)  (((x) > (high)) ? (high) : (((x) < (low)) ? (low) : (x)))

struct bt_adc {
	/* report value (mV) */
	int value;
	/* report type */
	int report_type;
	/* input device init value (mV) */
	int max, min;
	/* calibrated adc value */
	int cal;
	/*  adc scale value */
	int scale;
	/* invert report */
	bool invert;
	/* amux channel */
	int amux_ch;
	/* adc data tuning value([percent), p = positive, n = negative */
	int tuning_p, tuning_n;
    /* if use dedicated adc channel, it'll be saved here*/
    struct iio_channel *iio_ch;
};

struct analog_mux {
	/* IIO ADC Channel : amux connect channel */
	struct iio_channel *iio_ch;
	/* analog mux select(a,b) gpio */
	int sel_a_gpio, sel_b_gpio;
	/* analog mux enable gpio */
	int en_gpio;
};

struct bt_gpio {
	/* GPIO Request label */
	const char *label;
	/* GPIO Number */
	int num;
	/* report type */
	int report_type;
	/* report linux code */
	int linux_code;
	/* prev button value */
	bool old_value;
	/* button press level */
	bool active_level;
};

struct joypad {
	struct device *dev;
	int poll_interval;

	/* report enable/disable */
	bool enable;

	/* analog mux & joystick control */
	struct analog_mux *amux;
	/* analog mux max count */
	int amux_count;
    bool amux_dedicated;
	/* analog button */
	struct bt_adc *adcs;

	/* report reference point */
	bool invert_absx;
	bool invert_absy;
	bool invert_absrx;
	bool invert_absry;

	/* report interval (ms) */
	int bt_gpio_count;
	struct bt_gpio *gpios;

	/* button auto repeat */
	int auto_repeat;

	/* report threshold (mV) */
	int bt_adc_fuzz, bt_adc_flat;
	/* adc read value scale */
	int bt_adc_scale;
	/* joystick deadzone control */
	int bt_adc_deadzone;

	struct mutex lock;

	/* amux debug channel */
	int debug_ch;

	/* pwm device for rumble*/
	struct input_dev *input;
	struct pwm_device *pwm;
	struct work_struct play_work;
	u16 level;
	u16 boost_weak;
	u16 boost_strong;
};

static int pwm_vibrator_start(struct joypad *joypad)
{
	struct device *pdev = joypad->input->dev.parent;
	struct pwm_state state;
	int err;

	pwm_get_state(joypad->pwm, &state);
	pwm_set_relative_duty_cycle(&state, joypad->level, 0xffff);
	state.enabled = true;

	err = pwm_apply_state(joypad->pwm, &state);
	if (err) {
		dev_err(pdev, "failed to apply pwm state: %d", err);
		return err;
	}

	return 0;
}

static void pwm_vibrator_stop(struct joypad *joypad)
{
	pwm_disable(joypad->pwm);
}

static void pwm_vibrator_play_work(struct work_struct *work)
{
	struct joypad *joypad = container_of(work,
					struct joypad, play_work);

	if (joypad->level)
		pwm_vibrator_start(joypad);
	else
		pwm_vibrator_stop(joypad);
}


/*----------------------------------------------------------------------------*/
//
// set to the value in the boot.ini file. (if exist)
//
/*----------------------------------------------------------------------------*/
static unsigned int g_button_adc_fuzz = 0;
static unsigned int g_button_adc_flat = 0;
static unsigned int g_button_adc_scale = 0;
static unsigned int g_button_adc_deadzone = 0;

static int button_adc_fuzz(char *str)
{
	if (!str)
		return -EINVAL;
	g_button_adc_fuzz = simple_strtoul(str, NULL, 10);
	return 0;
}
__setup("button-adc-fuzz=", button_adc_fuzz);

static int button_adc_flat(char *str)
{
	if (!str)
		return -EINVAL;
	g_button_adc_flat = simple_strtoul(str, NULL, 10);
	return 0;
}
__setup("button-adc-flat=", button_adc_flat);

static int button_adc_scale(char *str)
{
	if (!str)
		return -EINVAL;
	g_button_adc_scale = simple_strtoul(str, NULL, 10);
	return 0;
}
__setup("button-adc-scale=", button_adc_scale);

static int button_adc_deadzone(char *str)
{
	if (!str)
		return -EINVAL;
	g_button_adc_deadzone = simple_strtoul(str, NULL, 10);
	return 0;
}
__setup("button-adc-deadzone=", button_adc_deadzone);

/*----------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------*/
static int joypad_amux_select(struct analog_mux *amux, int channel)
{
	/* select mux channel */
	gpio_set_value(amux->en_gpio, 0);

	switch(channel) {
		case 0:	/* EVENT (ABS_RY) */
			gpio_set_value(amux->sel_a_gpio, 0);
			gpio_set_value(amux->sel_b_gpio, 0);
			break;
		case 1:	/* EVENT (ABS_RX) */
			gpio_set_value(amux->sel_a_gpio, 0);
			gpio_set_value(amux->sel_b_gpio, 1);
			break;
		case 2:	/* EVENT (ABS_Y) */
			gpio_set_value(amux->sel_a_gpio, 1);
			gpio_set_value(amux->sel_b_gpio, 0);
			break;
		case 3:	/* EVENT (ABS_X) */
			gpio_set_value(amux->sel_a_gpio, 1);
			gpio_set_value(amux->sel_b_gpio, 1);
			break;
		default:
			/* amux disanle */
			gpio_set_value(amux->en_gpio, 1);
			return -1;
	}
	/* mux swtiching speed : 35ns(on) / 9ns(off) */
	usleep_range(10, 20);
	return 0;
}

/*----------------------------------------------------------------------------*/
static int joypad_adc_read(struct joypad *joypad, struct bt_adc *adc)
{
	int value;
    
    if(joypad->amux_dedicated){
        iio_read_channel_raw(adc->iio_ch, &value);
    }
    else{
        struct analog_mux *amux = joypad->amux;

        if (joypad_amux_select(amux, adc->amux_ch))
            return 0;

        iio_read_channel_raw(amux->iio_ch, &value);
    }
	value *= adc->scale;

	return value;
}

/*----------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------*/
/*
 * ATTRIBUTES:
 *
 * /sys/devices/platform/retrogame_joypad/poll_interval [rw]
 */
/*----------------------------------------------------------------------------*/
static ssize_t joypad_store_poll_interval(struct device *dev,
				      struct device_attribute *attr,
				      const char *buf,
				      size_t count)
{
	struct platform_device *pdev  = to_platform_device(dev);
	struct joypad *joypad = platform_get_drvdata(pdev);

	mutex_lock(&joypad->lock);
	joypad->poll_interval = simple_strtoul(buf, NULL, 10);
	mutex_unlock(&joypad->lock);

	return count;
}

/*----------------------------------------------------------------------------*/
static ssize_t joypad_show_poll_interval(struct device *dev,
				     struct device_attribute *attr,
				     char *buf)
{
	struct platform_device *pdev  = to_platform_device(dev);
	struct joypad *joypad = platform_get_drvdata(pdev);

	return sprintf(buf, "%d\n", joypad->poll_interval);
}

/*----------------------------------------------------------------------------*/
static DEVICE_ATTR(poll_interval, S_IWUSR | S_IRUGO,
		   joypad_show_poll_interval,
		   joypad_store_poll_interval);

/*----------------------------------------------------------------------------*/
/*
 * ATTRIBUTES:
 *
 * /sys/devices/platform/retrogame_joypad/adc_fuzz [r]
 */
/*----------------------------------------------------------------------------*/
static ssize_t joypad_show_adc_fuzz(struct device *dev,
				     struct device_attribute *attr,
				     char *buf)
{
	struct platform_device *pdev  = to_platform_device(dev);
	struct joypad *joypad = platform_get_drvdata(pdev);

	return sprintf(buf, "%d\n", joypad->bt_adc_fuzz);
}

/*----------------------------------------------------------------------------*/
static DEVICE_ATTR(adc_fuzz, S_IWUSR | S_IRUGO,
		   joypad_show_adc_fuzz,
		   NULL);

/*----------------------------------------------------------------------------*/
/*
 * ATTRIBUTES:
 *
 * /sys/devices/platform/retrogame_joypad/adc_flat [r]
 */
/*----------------------------------------------------------------------------*/
static ssize_t joypad_show_adc_flat(struct device *dev,
				     struct device_attribute *attr,
				     char *buf)
{
	struct platform_device *pdev  = to_platform_device(dev);
	struct joypad *joypad = platform_get_drvdata(pdev);

	return sprintf(buf, "%d\n", joypad->bt_adc_flat);
}

/*----------------------------------------------------------------------------*/
static DEVICE_ATTR(adc_flat, S_IWUSR | S_IRUGO,
		   joypad_show_adc_flat,
		   NULL);

/*----------------------------------------------------------------------------*/
/*
 * ATTRIBUTES:
 *
 * /sys/devices/platform/retrogame_joypad/enable [rw]
 */
/*----------------------------------------------------------------------------*/
static ssize_t joypad_store_enable(struct device *dev,
				      struct device_attribute *attr,
				      const char *buf,
				      size_t count)
{
	struct platform_device *pdev  = to_platform_device(dev);
	struct joypad *joypad = platform_get_drvdata(pdev);

	mutex_lock(&joypad->lock);
	joypad->enable = simple_strtoul(buf, NULL, 10);
	mutex_unlock(&joypad->lock);

	return count;
}

/*----------------------------------------------------------------------------*/
static ssize_t joypad_show_enable(struct device *dev,
				     struct device_attribute *attr,
				     char *buf)
{
	struct platform_device *pdev  = to_platform_device(dev);
	struct joypad *joypad = platform_get_drvdata(pdev);

	return sprintf(buf, "%d\n", joypad->enable);
}

/*----------------------------------------------------------------------------*/
static DEVICE_ATTR(enable, S_IWUSR | S_IRUGO,
		   joypad_show_enable,
		   joypad_store_enable);

/*----------------------------------------------------------------------------*/
/*
 * ATTRIBUTES:
 *
 * /sys/devices/platform/retrogame_joypad/adc_cal [rw]
 */
/*----------------------------------------------------------------------------*/
static ssize_t joypad_store_adc_cal(struct device *dev,
				      struct device_attribute *attr,
				      const char *buf,
				      size_t count)
{
	struct platform_device *pdev  = to_platform_device(dev);
	struct joypad *joypad = platform_get_drvdata(pdev);
	bool calibration;

	calibration = simple_strtoul(buf, NULL, 10);

	if (calibration) {
		int nbtn;

		mutex_lock(&joypad->lock);
		for (nbtn = 0; nbtn < joypad->amux_count; nbtn++) {
			struct bt_adc *adc = &joypad->adcs[nbtn];

			adc->value = joypad_adc_read(joypad, adc);
			if (!adc->value) {
				dev_err(joypad->dev, "%s : saradc channels[%d]!\n",
					__func__, nbtn);
				continue;
			}
			adc->cal = adc->value;
		}
		mutex_unlock(&joypad->lock);
	}
	return count;
}

/*----------------------------------------------------------------------------*/
static ssize_t joypad_show_adc_cal(struct device *dev,
				     struct device_attribute *attr,
				     char *buf)
{
	struct platform_device *pdev  = to_platform_device(dev);
	struct joypad *joypad = platform_get_drvdata(pdev);
	int nbtn;
	ssize_t pos;

	for (nbtn = 0, pos = 0; nbtn < joypad->amux_count; nbtn++) {
		struct bt_adc *adc = &joypad->adcs[nbtn];
		pos += sprintf(&buf[pos], "adc[%d]->cal = %d\n",
				nbtn, adc->cal);
	}
	pos += sprintf(&buf[pos], "adc scale = %d\n", joypad->bt_adc_scale);
	return pos;
}

/*----------------------------------------------------------------------------*/
static DEVICE_ATTR(adc_cal, S_IWUSR | S_IRUGO,
		   joypad_show_adc_cal,
		   joypad_store_adc_cal);

/*----------------------------------------------------------------------------*/
/*
 * ATTRIBUTES:
 *
 * /sys/devices/platform/retrogame_joypad/amux_debug [rw]
 *
 * echo [debug channel] > amux_debug
 * cat amux_debug : debug channel mux set & adc read
 */
/*----------------------------------------------------------------------------*/
static ssize_t joypad_store_amux_debug(struct device *dev,
				      struct device_attribute *attr,
				      const char *buf,
				      size_t count)
{
	struct platform_device *pdev  = to_platform_device(dev);
	struct joypad *joypad = platform_get_drvdata(pdev);

	joypad->debug_ch = simple_strtoul(buf, NULL, 10);

	/* if error than default setting(debug_ch = 0) */
	if (joypad->debug_ch > joypad->amux_count)
		joypad->debug_ch = 0;

	return count;
}

/*----------------------------------------------------------------------------*/
static ssize_t joypad_show_amux_debug(struct device *dev,
				     struct device_attribute *attr,
				     char *buf)
{
	struct platform_device *pdev  = to_platform_device(dev);
	struct joypad *joypad = platform_get_drvdata(pdev);
	ssize_t pos;
	int value;

	mutex_lock(&joypad->lock);

	/* disable poll driver */
	if (joypad->enable)
		joypad->enable = false;

    if(joypad->amux_dedicated){
        if (iio_read_channel_processed(joypad->adcs[joypad->debug_ch].iio_ch, &value))
            goto err_out;
    }
    else{
        struct analog_mux *amux = joypad->amux;	
        if (joypad_amux_select(amux, joypad->debug_ch))
            goto err_out;

        if (iio_read_channel_processed(amux->iio_ch, &value))
            goto err_out;
    }

	pos = sprintf(buf, "amux ch[%d], adc scale = %d, adc value = %d\n",
			joypad->debug_ch, joypad->bt_adc_scale,
			value * joypad->bt_adc_scale);
	goto out;

err_out:
	pos = sprintf(buf, "error : amux setup & adc read!\n");
out:
	mutex_unlock(&joypad->lock);
	return pos;
}

/*----------------------------------------------------------------------------*/
static DEVICE_ATTR(amux_debug, S_IWUSR | S_IRUGO,
		   joypad_show_amux_debug,
		   joypad_store_amux_debug);

/*----------------------------------------------------------------------------*/

#define __HDMI__

#ifdef __HDMI__
/*----------------------------------------------------------------------------*/
/*
 * ATTRIBUTES:
 *
 * /sys/devices/platform/singleadc-joypad/hdst [rw]
 */
/*----------------------------------------------------------------------------*/
static ssize_t joypad_store_hdst(struct device *dev,
				      struct device_attribute *attr,
				      const char *buf,
				      size_t count)
{
	return count;
}

/*----------------------------------------------------------------------------*/
static ssize_t joypad_show_hdst(struct device *dev,
				     struct device_attribute *attr,
				     char *buf)
{
	struct platform_device *pdev  = to_platform_device(dev);
	struct joypad *joypad = platform_get_drvdata(pdev);
	//int stcon;
	ssize_t pos=0;
	if(gpio_get_value(54)==1)
	{
		pos += sprintf(&buf[pos], "disconnected\n");
	}else{
		pos += sprintf(&buf[pos], "connected\n");
	}
	return pos;
}

/*----------------------------------------------------------------------------*/
static DEVICE_ATTR(hdst, S_IWUSR | S_IRUGO,
		   joypad_show_hdst,
		   joypad_store_hdst);
#endif

/*----------------------------------------------------------------------------*/
/*
 * ATTRIBUTES:
 *
 * /sys/devices/platform/odroidgo2_joypad/rumble_period [rw]
 */
/*----------------------------------------------------------------------------*/
static ssize_t joypad_store_period(struct device *dev,
				      struct device_attribute *attr,
				      const char *buf,
				      size_t count)
{
	struct platform_device *pdev  = to_platform_device(dev);
	struct joypad *joypad = platform_get_drvdata(pdev);

	mutex_lock(&joypad->lock);
	pwm_set_period(joypad->pwm, simple_strtoul(buf, NULL, 21));
	mutex_unlock(&joypad->lock);

	return count;
}

/*----------------------------------------------------------------------------*/
static ssize_t joypad_show_period(struct device *dev,
				     struct device_attribute *attr,
				     char *buf)
{
	struct platform_device *pdev  = to_platform_device(dev);
	struct joypad *joypad = platform_get_drvdata(pdev);

	return sprintf(buf, "%d\n", pwm_get_period(joypad->pwm));
}

/*----------------------------------------------------------------------------*/
static DEVICE_ATTR(rumble_period, S_IWUSR | S_IRUGO,
		   joypad_show_period,
		   joypad_store_period);


/*----------------------------------------------------------------------------*/
/*
 * ATTRIBUTES:
 *
 * /sys/devices/platform/odroidgo2_joypad/rumble_boost_strong [rw]
 */
/*----------------------------------------------------------------------------*/
static ssize_t joypad_store_boost_strong(struct device *dev,
				      struct device_attribute *attr,
				      const char *buf,
				      size_t count)
{
	struct platform_device *pdev  = to_platform_device(dev);
	struct joypad *joypad = platform_get_drvdata(pdev);

	mutex_lock(&joypad->lock);
	joypad->boost_strong = simple_strtoul(buf, NULL, 10);
	mutex_unlock(&joypad->lock);

	return count;
}

/*----------------------------------------------------------------------------*/
static ssize_t joypad_show_boost_strong(struct device *dev,
				     struct device_attribute *attr,
				     char *buf)
{
	struct platform_device *pdev  = to_platform_device(dev);
	struct joypad *joypad = platform_get_drvdata(pdev);

	return sprintf(buf, "%d\n", joypad->boost_strong);
}

/*----------------------------------------------------------------------------*/
static DEVICE_ATTR(rumble_boost_strong, S_IWUSR | S_IRUGO,
		   joypad_show_boost_strong,
		   joypad_store_boost_strong);

/*----------------------------------------------------------------------------*/
/*
 * ATTRIBUTES:
 *
 * /sys/devices/platform/odroidgo2_joypad/rumble_boost_weak [rw]
 */
/*----------------------------------------------------------------------------*/
static ssize_t joypad_store_boost_weak(struct device *dev,
				      struct device_attribute *attr,
				      const char *buf,
				      size_t count)
{
	struct platform_device *pdev  = to_platform_device(dev);
	struct joypad *joypad = platform_get_drvdata(pdev);

	mutex_lock(&joypad->lock);
	joypad->boost_weak = simple_strtoul(buf, NULL, 10);
	mutex_unlock(&joypad->lock);

	return count;
}

/*----------------------------------------------------------------------------*/
static ssize_t joypad_show_boost_weak(struct device *dev,
				     struct device_attribute *attr,
				     char *buf)
{
	struct platform_device *pdev  = to_platform_device(dev);
	struct joypad *joypad = platform_get_drvdata(pdev);

	return sprintf(buf, "%d\n", joypad->boost_weak);
}

/*----------------------------------------------------------------------------*/
static DEVICE_ATTR(rumble_boost_weak, S_IWUSR | S_IRUGO,
		   joypad_show_boost_weak,
		   joypad_store_boost_weak);

#ifdef __HDMI__
static struct attribute *joypad_attrs[] = {
	&dev_attr_poll_interval.attr,
	&dev_attr_adc_fuzz.attr,
	&dev_attr_adc_flat.attr,
	&dev_attr_enable.attr,
	&dev_attr_adc_cal.attr,
	&dev_attr_amux_debug.attr,
	&dev_attr_hdst.attr,
	&dev_attr_rumble_period.attr,
	&dev_attr_rumble_boost_strong.attr,
	&dev_attr_rumble_boost_weak.attr,
	NULL,
};
#else
/*----------------------------------------------------------------------------*/
static struct attribute *joypad_attrs[] = {
	&dev_attr_poll_interval.attr,
	&dev_attr_adc_fuzz.attr,
	&dev_attr_adc_flat.attr,
	&dev_attr_enable.attr,
	&dev_attr_adc_cal.attr,
	&dev_attr_amux_debug.attr,
	&dev_attr_rumble_period.attr,
	&dev_attr_rumble_boost_strong.attr,
	&dev_attr_rumble_boost_weak.attr,
	NULL,
};
#endif
static struct attribute_group joypad_attr_group = {
	.attrs = joypad_attrs,
};

/*----------------------------------------------------------------------------*/
static void joypad_gpio_check(struct input_polled_dev *poll_dev)
{
	struct joypad *joypad = poll_dev->private;
	int nbtn, value;

	for (nbtn = 0; nbtn < joypad->bt_gpio_count; nbtn++) {
		struct bt_gpio *gpio = &joypad->gpios[nbtn];

		if (gpio_get_value_cansleep(gpio->num) < 0) {
			dev_err(joypad->dev, "failed to get gpio state\n");
			continue;
		}
		value = gpio_get_value(gpio->num);
		if (value != gpio->old_value) {
			int keyval = (value == gpio->active_level) ? 1 : 0;
			dev_info(joypad->dev, "key status update, code=%d, val=%d", gpio->linux_code, keyval);
			input_event(poll_dev->input,
				gpio->report_type,
				gpio->linux_code,
				keyval);
			gpio->old_value = value;
		}
	}
	input_sync(poll_dev->input);
}

/*----------------------------------------------------------------------------*/
static void joypad_adc_check(struct input_polled_dev *poll_dev)
{
	struct joypad *joypad = poll_dev->private;
	int nbtn;

	for (nbtn = 0; nbtn < joypad->amux_count; nbtn++) {
		struct bt_adc *adc = &joypad->adcs[nbtn];

		int oldVal = adc->value;
		adc->value = joypad_adc_read(joypad, adc);
		if (!adc->value) {
			//dev_err(joypad->dev, "%s : saradc channels[%d]! adc->value : %d\n",__func__, nbtn, adc->value);
			continue;
		}
		adc->value = adc->value - adc->cal;

		/* Joystick Deadzone check */
		if (joypad->bt_adc_deadzone) {
			if (abs(adc->value) < joypad->bt_adc_deadzone)
				adc->value = 0;
		}

		/* adc data tuning */
		if (adc->tuning_n && adc->value < 0)
			adc->value = ADC_DATA_TUNING(adc->value, adc->tuning_n);
		if (adc->tuning_p && adc->value > 0)
			adc->value = ADC_DATA_TUNING(adc->value, adc->tuning_p);

		adc->value = adc->value > adc->max ? adc->max : adc->value;
		adc->value = adc->value < adc->min ? adc->min : adc->value;


		if(adc->value != oldVal)
		{
			//dev_info(joypad->dev, "saradc channels[%d]! adc->value : %d, oldVal : %d", nbtn, adc->value, oldVal);
		}

		input_report_abs(poll_dev->input,
			adc->report_type,
			adc->invert ? adc->value * (-1) : adc->value);
	}
	input_sync(poll_dev->input);
}

/*----------------------------------------------------------------------------*/
static void joypad_poll(struct input_polled_dev *poll_dev)
{
	struct joypad *joypad = poll_dev->private;

	if (joypad->enable) {
		joypad_adc_check(poll_dev);
		joypad_gpio_check(poll_dev);
	}
	if (poll_dev->poll_interval != joypad->poll_interval) {
		mutex_lock(&joypad->lock);
		poll_dev->poll_interval = joypad->poll_interval;
		mutex_unlock(&joypad->lock);
	}
}

/*----------------------------------------------------------------------------*/
static void joypad_open(struct input_polled_dev *poll_dev)
{
	struct joypad *joypad = poll_dev->private;
	int nbtn;

	for (nbtn = 0; nbtn < joypad->bt_gpio_count; nbtn++) {
		struct bt_gpio *gpio = &joypad->gpios[nbtn];
		gpio->old_value = gpio->active_level ? 0 : 1;
	}
	for (nbtn = 0; nbtn < joypad->amux_count; nbtn++) {
		struct bt_adc *adc = &joypad->adcs[nbtn];

		adc->value = joypad_adc_read(joypad, adc);
		if (!adc->value) {
			dev_err(joypad->dev, "%s : saradc channels[%d]!\n",
				__func__, nbtn);
			continue;
		}
		adc->cal = adc->value;
		dev_info(joypad->dev, "%s : adc[%d] adc->cal = %d\n",
			__func__, nbtn, adc->cal);
	}
	/* buttons status sync */
	joypad_adc_check(poll_dev);
	joypad_gpio_check(poll_dev);

	/* button report enable */
	mutex_lock(&joypad->lock);
	joypad->enable = true;
	mutex_unlock(&joypad->lock);

	dev_info(joypad->dev, "%s : opened\n", __func__);
}

/*----------------------------------------------------------------------------*/
static void joypad_close(struct input_polled_dev *poll_dev)
{
	struct joypad *joypad = poll_dev->private;

	/* button report disable */
	mutex_lock(&joypad->lock);
	joypad->enable = false;
	mutex_unlock(&joypad->lock);

	if(&joypad->play_work)
		cancel_work_sync(&joypad->play_work);
	pwm_vibrator_stop(joypad);

	dev_info(joypad->dev, "%s : closed\n", __func__);
}

/*----------------------------------------------------------------------------*/
static int joypad_amux_setup(struct device *dev, struct joypad *joypad)
{
	struct analog_mux *amux;
	enum iio_chan_type type;
	enum of_gpio_flags flags;
	int ret;
    if(joypad->amux_dedicated)
        return 0;

	/* analog mux control struct init */
	joypad->amux = devm_kzalloc(dev, sizeof(struct analog_mux),
					GFP_KERNEL);
	if (!joypad->amux) {
		dev_err(dev, "%s amux devm_kzmalloc error!", __func__);
		return -ENOMEM;
	}
	amux = joypad->amux;
	amux->iio_ch = devm_iio_channel_get(dev, "amux_adc");
	if (IS_ERR(amux->iio_ch)) {
		dev_err(dev, "iio channel get error\n");
		return -EINVAL;
	}
	if (!amux->iio_ch->indio_dev)
		return -ENXIO;

	if (iio_get_channel_type(amux->iio_ch, &type))
		return -EINVAL;

	if (type != IIO_VOLTAGE) {
		dev_err(dev, "Incompatible channel type %d\n", type);
		return -EINVAL;
	}

	amux->sel_a_gpio = of_get_named_gpio_flags(dev->of_node,
				"amux-a-gpios", 0, &flags);
	if (gpio_is_valid(amux->sel_a_gpio)) {
		ret = devm_gpio_request(dev, amux->sel_a_gpio, "amux-sel-a");
		if (ret < 0) {
			dev_err(dev, "%s : failed to request amux-sel-a %d\n",
				__func__, amux->sel_a_gpio);
			goto err_out;
		}
		ret = gpio_direction_output(amux->sel_a_gpio, 0);
		if (ret < 0)
			goto err_out;
	}

	amux->sel_b_gpio = of_get_named_gpio_flags(dev->of_node,
				"amux-b-gpios", 0, &flags);
	if (gpio_is_valid(amux->sel_b_gpio)) {
		ret = devm_gpio_request(dev, amux->sel_b_gpio, "amux-sel-b");
		if (ret < 0) {
			dev_err(dev, "%s : failed to request amux-sel-b %d\n",
				__func__, amux->sel_b_gpio);
			goto err_out;
		}
		ret = gpio_direction_output(amux->sel_b_gpio, 0);
		if (ret < 0)
			goto err_out;
	}

	amux->en_gpio = of_get_named_gpio_flags(dev->of_node,
				"amux-en-gpios", 0, &flags);
	if (gpio_is_valid(amux->en_gpio)) {
		ret = devm_gpio_request(dev, amux->en_gpio, "amux-en");
		if (ret < 0) {
			dev_err(dev, "%s : failed to request amux-en %d\n",
				__func__, amux->en_gpio);
			goto err_out;
		}
		ret = gpio_direction_output(amux->en_gpio, 0);
		if (ret < 0)
			goto err_out;
	}
	return	0;
err_out:
	return ret;
}

/*----------------------------------------------------------------------------*/
static int joypad_adc_setup(struct device *dev, struct joypad *joypad)
{
	int nbtn;

	/* adc button struct init */
	joypad->adcs = devm_kzalloc(dev, joypad->amux_count *
				sizeof(struct bt_adc), GFP_KERNEL);
	if (!joypad->adcs) {
		dev_err(dev, "%s devm_kzmalloc error!", __func__);
		return -ENOMEM;
	}

    enum iio_chan_type type;        
    struct iio_channel* channels;
    if(joypad->amux_dedicated){
        channels = devm_iio_channel_get_all(dev);

        if (IS_ERR(channels)) {
            dev_err(dev, "iio channel get error\n");
            return -EINVAL;
        }
    }

	for (nbtn = 0; nbtn < joypad->amux_count; nbtn++) {
		struct bt_adc *adc = &joypad->adcs[nbtn];
        if(joypad->amux_dedicated){
            struct iio_channel* ch = &channels[nbtn];
            adc->iio_ch = ch;
            if (IS_ERR(adc->iio_ch)) {
                dev_err(dev, "[ch:%d] iio channel get error\n", nbtn);
                return -EINVAL;
            }
            if (!adc->iio_ch->indio_dev)
                return -ENXIO;

            if (iio_get_channel_type(adc->iio_ch, &type))
                return -EINVAL;

            if (type != IIO_VOLTAGE) {
                dev_err(dev, "[ch:%d] Incompatible channel type %d\n", nbtn, type);
                return -EINVAL;
            }
        }        

		adc->scale = joypad->bt_adc_scale;

		adc->max = (ADC_MAX_VOLTAGE / 2);
		adc->min = (ADC_MAX_VOLTAGE / 2) * (-1);
		if (adc->scale) {
			adc->max *= adc->scale;
			adc->min *= adc->scale;
		}
		adc->amux_ch = nbtn;
		adc->invert = false;

		switch (nbtn) {
			case 0:
				if (joypad->invert_absry)
					adc->invert = true;
				adc->report_type = ABS_RY;
				if (device_property_read_u32(dev,
					"abs_ry-p-tuning",
					&adc->tuning_p))
					adc->tuning_p = ADC_TUNING_DEFAULT;
				if (device_property_read_u32(dev,
					"abs_ry-n-tuning",
					&adc->tuning_n))
					adc->tuning_n = ADC_TUNING_DEFAULT;
				break;
			case 1:
				if (joypad->invert_absrx)
					adc->invert = true;
				adc->report_type = ABS_RX;
				if (device_property_read_u32(dev,
					"abs_rx-p-tuning",
					&adc->tuning_p))
					adc->tuning_p = ADC_TUNING_DEFAULT;
				if (device_property_read_u32(dev,
					"abs_rx-n-tuning",
					&adc->tuning_n))
					adc->tuning_n = ADC_TUNING_DEFAULT;
				break;
			case 2:
				if (joypad->invert_absy)
					adc->invert = true;
				adc->report_type = ABS_Y;
				if (device_property_read_u32(dev,
					"abs_y-p-tuning",
					&adc->tuning_p))
					adc->tuning_p = ADC_TUNING_DEFAULT;
				if (device_property_read_u32(dev,
					"abs_y-n-tuning",
					&adc->tuning_n))
					adc->tuning_n = ADC_TUNING_DEFAULT;
				break;
			case 3:
				if (joypad->invert_absx)
					adc->invert = true;
				adc->report_type = ABS_X;
				if (device_property_read_u32(dev,
					"abs_x-p-tuning",
					&adc->tuning_p))
					adc->tuning_p = ADC_TUNING_DEFAULT;
				if (device_property_read_u32(dev,
					"abs_x-n-tuning",
					&adc->tuning_n))
					adc->tuning_n = ADC_TUNING_DEFAULT;
				break;
			default :
				dev_err(dev, "%s amux count(%d) error!",
					__func__, nbtn);
				return -EINVAL;
		}
	}
	return	0;
}

/*----------------------------------------------------------------------------*/
static int joypad_gpio_setup(struct device *dev, struct joypad *joypad)
{
	struct device_node *node, *pp;
	int nbtn;

	node = dev->of_node;
	if (!node)
		return -ENODEV;

	joypad->gpios = devm_kzalloc(dev, joypad->bt_gpio_count *
				sizeof(struct bt_gpio), GFP_KERNEL);

	if (!joypad->gpios) {
		dev_err(dev, "%s devm_kzmalloc error!", __func__);
		return -ENOMEM;
	}

	nbtn = 0;
	for_each_child_of_node(node, pp) {
		enum of_gpio_flags flags;
		struct bt_gpio *gpio = &joypad->gpios[nbtn++];
		int error;

		gpio->num = of_get_gpio_flags(pp, 0, &flags);
		if (gpio->num < 0) {
			error = gpio->num;
			dev_err(dev, "Failed to get gpio flags, error: %d\n",
				error);
			return error;
		}

		/* gpio active level(key press level) */
		gpio->active_level = (flags & OF_GPIO_ACTIVE_LOW) ? 0 : 1;

		gpio->label = of_get_property(pp, "label", NULL);

		if (gpio_is_valid(gpio->num)) {
			error = devm_gpio_request_one(dev, gpio->num,
						      GPIOF_IN, gpio->label);
			if (error < 0) {
				dev_err(dev,
					"Failed to request GPIO %d, error %d\n",
					gpio->num, error);
				return error;
			}
		}
		if (of_property_read_u32(pp, "linux,code", &gpio->linux_code)) {
			dev_err(dev, "Button without keycode: 0x%x\n",
				gpio->num);
			return -EINVAL;
		}
		if (of_property_read_u32(pp, "linux,input-type",
				&gpio->report_type))
			gpio->report_type = EV_KEY;
	}
	if (nbtn == 0)
		return -EINVAL;

	return	0;
}

static int rumble_play_effect(struct input_dev *dev, void *data, struct ff_effect *effect)
{
	struct joypad *joypad = data;
	u32 boosted_level;
	if (effect->type != FF_RUMBLE)
		return 0;

	if (effect->u.rumble.strong_magnitude)
		boosted_level = effect->u.rumble.strong_magnitude + joypad->boost_strong;
	else
		boosted_level = effect->u.rumble.weak_magnitude + joypad->boost_weak;

	joypad->level = (u16)CLAMP(boosted_level, 0, 0xffff);

	dev_info(joypad->dev,"joypad->level = %d",  joypad->level);
	schedule_work(&joypad->play_work);
	return 0;
}

/*----------------------------------------------------------------------------*/
static int joypad_rumble_setup(struct device *dev, struct joypad *joypad)
{
	int err;
	struct pwm_state state;

	joypad->pwm = devm_pwm_get(dev, "enable");
	if (IS_ERR(joypad->pwm))
	{
		dev_err(dev, "rumble get error\n");
		return -EINVAL;
	}

	INIT_WORK(&joypad->play_work, pwm_vibrator_play_work);

	/* Sync up PWM state and ensure it is off. */
	pwm_init_state(joypad->pwm, &state);
	state.enabled = false;
	err = pwm_apply_state(joypad->pwm, &state);
	if (err) {
		dev_err(dev, "failed to apply initial PWM state: %d",
			err);
		return err;
	}
	dev_info(dev, "rumble setup success!\n");
	return 0;
}

/*----------------------------------------------------------------------------*/
struct input_dev * joypad_input_g;


void rk_send_key_f_key_up(void)
{
	if (!joypad_input_g)
		return;

	input_report_key(joypad_input_g, BTN_MODE, 1);
	input_sync(joypad_input_g);
}
EXPORT_SYMBOL(rk_send_key_f_key_up);


void rk_send_key_f_key_down(void)
{
	if (!joypad_input_g)
		return;

	input_report_key(joypad_input_g, BTN_MODE, 0);
	input_sync(joypad_input_g);
}
EXPORT_SYMBOL(rk_send_key_f_key_down);


static int joypad_input_setup(struct device *dev, struct joypad *joypad)
{
	struct input_polled_dev *poll_dev;
	struct input_dev *input;
	int nbtn, error;
	u32 joypad_revision = 0;
	u32 joypad_product = 0;
	u32 boost_weak = 0;
	u32 boost_strong = 0;
	poll_dev = devm_input_allocate_polled_device(dev);
	if (!poll_dev) {
		dev_err(dev, "no memory for polled device\n");
		return -ENOMEM;
	}

	poll_dev->private	= joypad;
	poll_dev->poll		= joypad_poll;
	poll_dev->poll_interval	= joypad->poll_interval;
	poll_dev->open		= joypad_open;
	poll_dev->close		= joypad_close;

	input = poll_dev->input;
	joypad->input = poll_dev->input;

	device_property_read_string(dev, "joypad-name", &input->name);
	input->phys = DRV_NAME"/input0";

	device_property_read_u32(dev, "joypad-revision", &joypad_revision);
	device_property_read_u32(dev, "joypad-product", &joypad_product);
	input->id.bustype = BUS_HOST;
	input->id.vendor  = 0x484B;
	input->id.product = (u16)joypad_product;
	input->id.version = (u16)joypad_revision;

	/* IIO ADC key setup (0 mv ~ 1800 mv) * adc->scale */
	__set_bit(EV_ABS, input->evbit);
	for(nbtn = 0; nbtn < joypad->amux_count; nbtn++) {
		struct bt_adc *adc = &joypad->adcs[nbtn];
		input_set_abs_params(input, adc->report_type,
				adc->min, adc->max,
				joypad->bt_adc_fuzz,
				joypad->bt_adc_flat);
		dev_info(dev,
			"%s : SCALE = %d, ABS min = %d, max = %d,"
			" fuzz = %d, flat = %d, deadzone = %d\n",
			__func__, adc->scale, adc->min, adc->max,
			joypad->bt_adc_fuzz, joypad->bt_adc_flat,
			joypad->bt_adc_deadzone);
		dev_info(dev,
			"%s : adc tuning_p = %d, adc_tuning_n = %d\n\n",
			__func__, adc->tuning_p, adc->tuning_n);
	}

	/* Rumble setip*/
	device_property_read_u32(dev, "rumble-boost-weak", &boost_weak);
	device_property_read_u32(dev, "rumble-boost-strong", &boost_strong);
	joypad->boost_weak = boost_weak;
	joypad->boost_strong = boost_strong;
	dev_info(dev, "Boost = %d, %d",boost_weak, boost_strong);
	input_set_capability(input, EV_FF, FF_RUMBLE);
	error = input_ff_create_memless(input, joypad, rumble_play_effect);
	if (error) {
		dev_err(dev, "unable to register rumble, err=%d\n",
			error);
		return error;
	}

	/* GPIO key setup */
	__set_bit(EV_KEY, input->evbit);
	for(nbtn = 0; nbtn < joypad->bt_gpio_count; nbtn++) {
		struct bt_gpio *gpio = &joypad->gpios[nbtn];
		input_set_capability(input, gpio->report_type,
				gpio->linux_code);
	}

	if (joypad->auto_repeat)
		__set_bit(EV_REP, input->evbit);

	joypad->dev = dev;

	error = input_register_polled_device(poll_dev);
	if (error) {
		dev_err(dev, "unable to register polled device, err=%d\n",
			error);
		return error;
	}
	return 0;
}

/*----------------------------------------------------------------------------*/
static void joypad_setup_value_check(struct device *dev, struct joypad *joypad)
{
	/*
		fuzz: specifies fuzz value that is used to filter noise from
			the event stream.
	*/
	if (g_button_adc_fuzz)
		joypad->bt_adc_fuzz = g_button_adc_fuzz;
	else
		device_property_read_u32(dev, "button-adc-fuzz",
					&joypad->bt_adc_fuzz);
	/*
		flat: values that are within this value will be discarded by
			joydev interface and reported as 0 instead.
	*/
	if (g_button_adc_flat)
		joypad->bt_adc_flat = g_button_adc_flat;
	else
		device_property_read_u32(dev, "button-adc-flat",
					&joypad->bt_adc_flat);

	/* Joystick report value control */
	if (g_button_adc_scale)
		joypad->bt_adc_scale = g_button_adc_scale;
	else
		device_property_read_u32(dev, "button-adc-scale",
					&joypad->bt_adc_scale);

	/* Joystick deadzone value control */
	if (g_button_adc_deadzone)
		joypad->bt_adc_deadzone = g_button_adc_deadzone;
	else
		device_property_read_u32(dev, "button-adc-deadzone",
					&joypad->bt_adc_deadzone);

}

/*----------------------------------------------------------------------------*/
static int joypad_dt_parse(struct device *dev, struct joypad *joypad)
{
	int error = 0;

	/* initialize value check from boot.ini */
	joypad_setup_value_check(dev, joypad);

	device_property_read_u32(dev, "amux-count",
				&joypad->amux_count);

    joypad->amux_dedicated = device_property_read_bool(dev, "amux-dedicated-adc");

	device_property_read_u32(dev, "poll-interval",
				&joypad->poll_interval);

	joypad->auto_repeat = device_property_present(dev, "autorepeat");

	/* change the report reference point? (ADC MAX - read value) */
	joypad->invert_absx = device_property_present(dev, "invert-absx");
	joypad->invert_absy = device_property_present(dev, "invert-absy");
	joypad->invert_absrx = device_property_present(dev, "invert-absrx");
	joypad->invert_absry = device_property_present(dev, "invert-absry");
	dev_info(dev, "%s : invert-absx = %d, inveret-absy = %d, invert-absrx = %d, inveret-absry = %d\n",
		__func__, joypad->invert_absx, joypad->invert_absy, joypad->invert_absrx, joypad->invert_absry);

	joypad->bt_gpio_count = device_get_child_node_count(dev);

	if ((joypad->amux_count == 0) || (joypad->bt_gpio_count == 0)) {
		dev_err(dev, "adc key = %d, gpio key = %d error!",
			joypad->amux_count, joypad->bt_gpio_count);
		return -EINVAL;
	}

	error = joypad_adc_setup(dev, joypad);
	if (error)
		return error;

	error = joypad_amux_setup(dev, joypad);
	if (error)
		return error;

	error = joypad_gpio_setup(dev, joypad);
	if (error)
		return error;

	dev_info(dev, "%s : adc key cnt = %d, gpio key cnt = %d\n",
			__func__, joypad->amux_count, joypad->bt_gpio_count);

	return error;
}

static int __maybe_unused joypad_suspend(struct device *dev)
{
	struct platform_device *pdev  = to_platform_device(dev);
	struct joypad *joypad = platform_get_drvdata(pdev);

	cancel_work_sync(&joypad->play_work);
	if (joypad->level)
		pwm_vibrator_stop(joypad);

	return 0;
}

static int __maybe_unused joypad_resume(struct device *dev)
{
	struct platform_device *pdev  = to_platform_device(dev);
	struct joypad *joypad = platform_get_drvdata(pdev);

	if (joypad->level)
		pwm_vibrator_start(joypad);

	return 0;
}

static SIMPLE_DEV_PM_OPS(joypad_pm_ops,
			 joypad_suspend, joypad_resume);
/*----------------------------------------------------------------------------*/
static int joypad_probe(struct platform_device *pdev)
{
	struct joypad *joypad;
	struct device *dev = &pdev->dev;
	int error;

	joypad = devm_kzalloc(dev, sizeof(struct joypad), GFP_KERNEL);
	if (!joypad) {
		dev_err(dev, "joypad devm_kzmalloc error!");
		return -ENOMEM;
	}

	/* device tree data parse */
	error = joypad_dt_parse(dev, joypad);
	if (error) {
		dev_err(dev, "dt parse error!(err = %d)\n", error);
		return error;
	}

	mutex_init(&joypad->lock);
	platform_set_drvdata(pdev, joypad);

	error = sysfs_create_group(&pdev->dev.kobj, &joypad_attr_group);
	if (error) {
		dev_err(dev, "create sysfs group fail, error: %d\n",
			error);
		return error;
	}

	/* poll input device setup */
	error = joypad_input_setup(dev, joypad);
	if (error) {
		dev_err(dev, "input setup failed!(err = %d)\n", error);
		return error;
	}

	/* rumble setup */
	error = joypad_rumble_setup(dev, joypad);
	if (error) {
		dev_err(dev, "rumble setup failed!(err = %d)\n", error);
		return error;
	}

	dev_info(dev, "%s : probe success\n", __func__);
	return 0;
}

/*----------------------------------------------------------------------------*/
static const struct of_device_id joypad_of_match[] = {
	{ .compatible = "saradc-joypad", },
	{},
};

MODULE_DEVICE_TABLE(of, joypad_of_match);

/*----------------------------------------------------------------------------*/
static struct platform_driver joypad_driver = {
	.probe = joypad_probe,
	.driver = {
		.name = DRV_NAME,
		.pm = &joypad_pm_ops,
		.of_match_table = of_match_ptr(joypad_of_match),
	},
};

/*----------------------------------------------------------------------------*/
static int __init joypad_init(void)
{
	return platform_driver_register(&joypad_driver);
}

/*----------------------------------------------------------------------------*/
static void __exit joypad_exit(void)
{
	platform_driver_unregister(&joypad_driver);
}

/*----------------------------------------------------------------------------*/
late_initcall(joypad_init);
module_exit(joypad_exit);