Linux/TSC2007: Regarding Device tree configuration on Android.

/*
 * drivers/input/touchscreen/tsc2007.c
 *
 * Copyright (c) 2008 MtekVision Co., Ltd.
 *	Kwangwoo Lee <kwlee@mtekvision.com>
 *
 * Using code from:
 *  - ads7846.c
 *	Copyright (c) 2005 David Brownell
 *	Copyright (c) 2006 Nokia Corporation
 *  - corgi_ts.c
 *	Copyright (C) 2004-2005 Richard Purdie
 *  - omap_ts.[hc], ads7846.h, ts_osk.c
 *	Copyright (C) 2002 MontaVista Software
 *	Copyright (C) 2004 Texas Instruments
 *	Copyright (C) 2005 Dirk Behme
 *
 *  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/slab.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/i2c.h>
#include <linux/i2c/tsc2007.h>
#include <linux/pm.h>

#if defined(CONFIG_HAS_EARLYSUSPEND)
#include <linux/earlysuspend.h>
#define TSC2007_SUSPEND_LEVEL 1
#endif

#define TSC2007_MEASURE_TEMP0		(0x0 << 4)
#define TSC2007_MEASURE_AUX		(0x2 << 4)
#define TSC2007_MEASURE_TEMP1		(0x4 << 4)
#define TSC2007_ACTIVATE_XN		(0x8 << 4)
#define TSC2007_ACTIVATE_YN		(0x9 << 4)
#define TSC2007_ACTIVATE_YP_XN		(0xa << 4)
#define TSC2007_SETUP			(0xb << 4)
#define TSC2007_MEASURE_X		(0xc << 4)
#define TSC2007_MEASURE_Y		(0xd << 4)
#define TSC2007_MEASURE_Z1		(0xe << 4)
#define TSC2007_MEASURE_Z2		(0xf << 4)

#define TSC2007_POWER_OFF_IRQ_EN	(0x0 << 2)
#define TSC2007_ADC_ON_IRQ_DIS0		(0x1 << 2)
#define TSC2007_ADC_OFF_IRQ_EN		(0x2 << 2)
#define TSC2007_ADC_ON_IRQ_DIS1		(0x3 << 2)

#define TSC2007_12BIT			(0x0 << 1)
#define TSC2007_8BIT			(0x1 << 1)

#define	MAX_12BIT			((1 << 12) - 1)

#define ADC_ON_12BIT	(TSC2007_12BIT | TSC2007_ADC_ON_IRQ_DIS0)

#define READ_Y		(ADC_ON_12BIT | TSC2007_MEASURE_Y)
#define READ_Z1		(ADC_ON_12BIT | TSC2007_MEASURE_Z1)
#define READ_Z2		(ADC_ON_12BIT | TSC2007_MEASURE_Z2)
#define READ_X		(ADC_ON_12BIT | TSC2007_MEASURE_X)
#define PWRDOWN		(TSC2007_12BIT | TSC2007_POWER_OFF_IRQ_EN)

struct ts_event {
	u16	x;
	u16	y;
	u16	z1, z2;
};

struct tsc2007 {
	struct input_dev	*input;
	char			phys[32];
	struct delayed_work	work;

	struct i2c_client	*client;

	u16			model;
	u16			x_plate_ohms;
	u16			max_rt;
	unsigned long		poll_delay;
	unsigned long		poll_period;
	u16			min_x;
	u16			max_x;
	u16			min_y;
	u16			max_y;

	bool			pendown;
	int			irq;

	bool			invert_x;
	bool			invert_y;
	bool			invert_z1;
	bool			invert_z2;

	int			(*get_pendown_state)(void);
	void			(*clear_penirq)(void);
	int			(*power_shutdown)(bool);
#if defined(CONFIG_HAS_EARLYSUSPEND)
	struct early_suspend	early_suspend;
#endif
};

static inline int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
{
	s32 data;
	u16 val;

	data = i2c_smbus_read_word_data(tsc->client, cmd);
	if (data < 0) {
		dev_err(&tsc->client->dev, "i2c io error: %d\n", data);
		return data;
	}

	/* The protocol and raw data format from i2c interface:
	 * S Addr Wr [A] Comm [A] S Addr Rd [A] [DataLow] A [DataHigh] NA P
	 * Where DataLow has [D11-D4], DataHigh has [D3-D0 << 4 | Dummy 4bit].
	 */
	val = swab16(data) >> 4;

	dev_dbg(&tsc->client->dev, "data: 0x%x, val: 0x%x\n", data, val);

	return val;
}

static void tsc2007_read_values(struct tsc2007 *tsc, struct ts_event *tc)
{
	/* y- still on; turn on only y+ (and ADC) */
	tc->y = tsc2007_xfer(tsc, READ_Y);

	/* turn y- off, x+ on, then leave in lowpower */
	tc->x = tsc2007_xfer(tsc, READ_X);

	/* turn y+ off, x- on; we'll use formula #1 */
	tc->z1 = tsc2007_xfer(tsc, READ_Z1);
	tc->z2 = tsc2007_xfer(tsc, READ_Z2);

	if (tsc->invert_x == true)
		tc->x = MAX_12BIT - tc->x;

	if (tsc->invert_y == true)
		tc->y = MAX_12BIT - tc->y;

	if (tsc->invert_z1 == true)
		tc->z1 = MAX_12BIT - tc->z1;

	if (tsc->invert_z2 == true)
		tc->z2 = MAX_12BIT - tc->z2;

	/* Prepare for next touch reading - power down ADC, enable PENIRQ */
	tsc2007_xfer(tsc, PWRDOWN);
}

static u32 tsc2007_calculate_pressure(struct tsc2007 *tsc, struct ts_event *tc)
{
	u32 rt = 0;

	/* range filtering */
	if (tc->x == MAX_12BIT)
		tc->x = 0;

	if (likely(tc->x && tc->z1)) {
		/* compute touch pressure resistance using equation #1 */
		rt = tc->z2 - tc->z1;
		rt *= tc->x;
		rt *= tsc->x_plate_ohms;
		rt /= tc->z1;
		rt = (rt + 2047) >> 12;
	}

	return rt;
}

static void tsc2007_send_up_event(struct tsc2007 *tsc)
{
	struct input_dev *input = tsc->input;

	dev_dbg(&tsc->client->dev, "UP\n");

	input_report_key(input, BTN_TOUCH, 0);
	input_report_abs(input, ABS_PRESSURE, 0);
	input_sync(input);
}

static void tsc2007_work(struct work_struct *work)
{
	struct tsc2007 *ts =
		container_of(to_delayed_work(work), struct tsc2007, work);
	bool debounced = false;
	struct ts_event tc;
	u32 rt;

	/*
	 * NOTE: We can't rely on the pressure to determine the pen down
	 * state, even though this controller has a pressure sensor.
	 * The pressure value can fluctuate for quite a while after
	 * lifting the pen and in some cases may not even settle at the
	 * expected value.
	 *
	 * The only safe way to check for the pen up condition is in the
	 * work function by reading the pen signal state (it's a GPIO
	 * and IRQ). Unfortunately such callback is not always available,
	 * in that case we have rely on the pressure anyway.
	 */
	if (ts->get_pendown_state) {
		if (unlikely(!ts->get_pendown_state())) {
			tsc2007_send_up_event(ts);
			ts->pendown = false;
			goto out;
		}

		dev_dbg(&ts->client->dev, "pen is still down\n");
	}

	tsc2007_read_values(ts, &tc);

	rt = tsc2007_calculate_pressure(ts, &tc);
	if (rt > ts->max_rt) {
		/*
		 * Sample found inconsistent by debouncing or pressure is
		 * beyond the maximum. Don't report it to user space,
		 * repeat at least once more the measurement.
		 */
		dev_dbg(&ts->client->dev, "ignored pressure %d\n", rt);
		debounced = true;
		goto out;

	}

	if (rt) {
		struct input_dev *input = ts->input;

		if (!ts->pendown) {
			dev_dbg(&ts->client->dev, "DOWN\n");

			input_report_key(input, BTN_TOUCH, 1);
			ts->pendown = true;
		}

		input_report_abs(input, ABS_X, tc.x);
		input_report_abs(input, ABS_Y, tc.y);
		input_report_abs(input, ABS_PRESSURE, rt);

		input_sync(input);

		dev_dbg(&ts->client->dev, "point(%4d,%4d), pressure (%4u)\n",
			tc.x, tc.y, rt);

	} else if (!ts->get_pendown_state && ts->pendown) {
		/*
		 * We don't have callback to check pendown state, so we
		 * have to assume that since pressure reported is 0 the
		 * pen was lifted up.
		 */
		tsc2007_send_up_event(ts);
		ts->pendown = false;
	}

 out:
	if (ts->pendown || debounced)
		schedule_delayed_work(&ts->work,
				      msecs_to_jiffies(ts->poll_period));
	else
		enable_irq(ts->irq);
}

static irqreturn_t tsc2007_irq(int irq, void *handle)
{
	struct tsc2007 *ts = handle;

	if (!ts->get_pendown_state || likely(ts->get_pendown_state())) {
		disable_irq_nosync(ts->irq);
		schedule_delayed_work(&ts->work,
				      msecs_to_jiffies(ts->poll_delay));
	}

	if (ts->clear_penirq)
		ts->clear_penirq();

	return IRQ_HANDLED;
}

static void tsc2007_free_irq(struct tsc2007 *ts)
{
	free_irq(ts->irq, ts);
	if (cancel_delayed_work_sync(&ts->work)) {
		/*
		 * Work was pending, therefore we need to enable
		 * IRQ here to balance the disable_irq() done in the
		 * interrupt handler.
		 */
		enable_irq(ts->irq);
	}
}

#ifdef CONFIG_PM
static int tsc2007_suspend(struct device *dev)
{
	int rc;
	struct tsc2007	*ts = dev_get_drvdata(dev);

	disable_irq(ts->irq);

	if (cancel_delayed_work_sync(&ts->work))
		enable_irq(ts->irq);

	if (ts->power_shutdown) {
		rc = ts->power_shutdown(true);
		if (rc) {
			pr_err("%s: Power off failed, suspend failed (%d)\n",
							__func__, rc);
			return rc;
		}
	}

	return 0;
}

static int tsc2007_resume(struct device *dev)
{
	int rc;
	struct tsc2007	*ts = dev_get_drvdata(dev);

	if (ts->power_shutdown) {
		rc = ts->power_shutdown(false);
		if (rc) {
			pr_err("%s: Power on failed, resume failed (%d)\n",
							 __func__, rc);
			return rc;
		}
	}

	enable_irq(ts->irq);

	return 0;
}

#ifdef CONFIG_HAS_EARLYSUSPEND
static void tsc2007_early_suspend(struct early_suspend *h)
{
	struct tsc2007 *ts = container_of(h, struct tsc2007, early_suspend);

	tsc2007_suspend(&ts->client->dev);
}

static void tsc2007_late_resume(struct early_suspend *h)
{
	struct tsc2007 *ts = container_of(h, struct tsc2007, early_suspend);

	tsc2007_resume(&ts->client->dev);
}
#endif

static const struct dev_pm_ops tsc2007_pm_ops = {
#ifndef CONFIG_HAS_EARLYSUSPEND
	.suspend	= tsc2007_suspend,
	.resume		= tsc2007_resume,
#endif
};
#endif

static int tsc2007_probe(struct i2c_client *client,
				   const struct i2c_device_id *id)
{
	struct tsc2007 *ts;
	struct tsc2007_platform_data *pdata = client->dev.platform_data;
	struct input_dev *input_dev;
	int err;

	if (!pdata) {
		dev_err(&client->dev, "platform data is required!\n");
		return -EINVAL;
	}

	if (!i2c_check_functionality(client->adapter,
				     I2C_FUNC_SMBUS_READ_WORD_DATA))
		return -EIO;

	ts = kzalloc(sizeof(struct tsc2007), GFP_KERNEL);
	input_dev = input_allocate_device();
	if (!ts || !input_dev) {
		err = -ENOMEM;
		goto err_free_mem;
	}
	//whitney add 20190220
#if 0
#ifdef GTP_CONFIG_OF	/* device tree support */
	if (client->dev.of_node) {
		ret = gt1x_parse_dt(&client->dev);
		if (ret < 0) {
        	GTP_ERROR("GTP parse dts failed.");
        	return ret;
    	}
	}
#endif
#endif
//add  end  20190220
	ts->client = client;
	ts->irq = client->irq;
	ts->input = input_dev;
	INIT_DELAYED_WORK(&ts->work, tsc2007_work);

	ts->model             = pdata->model;
	ts->x_plate_ohms      = pdata->x_plate_ohms;
	ts->max_rt            = pdata->max_rt ? : MAX_12BIT;
	ts->poll_delay        = pdata->poll_delay ? : 1;
	ts->poll_period       = pdata->poll_period ? : 1;
	ts->get_pendown_state = pdata->get_pendown_state;
	ts->clear_penirq      = pdata->clear_penirq;
	ts->invert_x	      = pdata->invert_x;
	ts->invert_y	      = pdata->invert_y;
	ts->invert_z1	      = pdata->invert_z1;
	ts->invert_z2	      = pdata->invert_z2;
	ts->min_x	      = pdata->min_x ? pdata->min_x : 0;
	ts->max_x	      = pdata->max_x ? pdata->max_x : MAX_12BIT;
	ts->min_y	      = pdata->min_y ? pdata->min_y : 0;
	ts->max_y	      = pdata->max_y ? pdata->max_y : MAX_12BIT;
	ts->power_shutdown    = pdata->power_shutdown;

	snprintf(ts->phys, sizeof(ts->phys),
		 "%s/input0", dev_name(&client->dev));

	input_dev->name = "TSC2007 Touchscreen";
	input_dev->phys = ts->phys;
	input_dev->id.bustype = BUS_I2C;

	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
	input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
	__set_bit(INPUT_PROP_DIRECT, input_dev->propbit);

	input_set_abs_params(input_dev, ABS_X, ts->min_x,
				ts->max_x, pdata->fuzzx, 0);
	input_set_abs_params(input_dev, ABS_Y, ts->min_y,
				ts->max_y, pdata->fuzzy, 0);
	input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT,
			pdata->fuzzz, 0);

	if (pdata->init_platform_hw)
		pdata->init_platform_hw();

	err = request_irq(ts->irq, tsc2007_irq, pdata->irq_flags,
			client->dev.driver->name, ts);
	if (err < 0) {
		dev_err(&client->dev, "irq %d busy?\n", ts->irq);
		goto err_free_mem;
	}

	/* Prepare for touch readings - power down ADC and enable PENIRQ */
	err = tsc2007_xfer(ts, PWRDOWN);
	if (err < 0)
		goto err_free_irq;

	err = input_register_device(input_dev);
	if (err)
		goto err_free_irq;

#ifdef CONFIG_HAS_EARLYSUSPEND
	ts->early_suspend.level = EARLY_SUSPEND_LEVEL_BLANK_SCREEN +
						TSC2007_SUSPEND_LEVEL;
	ts->early_suspend.suspend = tsc2007_early_suspend;
	ts->early_suspend.resume = tsc2007_late_resume;
	register_early_suspend(&ts->early_suspend);
#endif

	i2c_set_clientdata(client, ts);

	return 0;

 err_free_irq:
	tsc2007_free_irq(ts);
	if (pdata->exit_platform_hw)
		pdata->exit_platform_hw();
 err_free_mem:
	input_free_device(input_dev);
	kfree(ts);
	return err;
}

static int tsc2007_remove(struct i2c_client *client)
{
	struct tsc2007	*ts = i2c_get_clientdata(client);
	struct tsc2007_platform_data *pdata = client->dev.platform_data;

	tsc2007_free_irq(ts);

	if (pdata->exit_platform_hw)
		pdata->exit_platform_hw();

#ifdef CONFIG_HAS_EARLYSUSPEND
	unregister_early_suspend(&ts->early_suspend);
#endif
	input_unregister_device(ts->input);
	kfree(ts);

	return 0;
}

static const struct i2c_device_id tsc2007_idtable[] = {
	{ "tsc2007", 0 },
	{ }
};

MODULE_DEVICE_TABLE(i2c, tsc2007_idtable);

//whitney add 
#if 0
#ifdef CONFIG_PM
		static struct of_device_id tsc2007_dt_match[] = {
	{ .compatible = "tsc,tsc2007" },
	{ }
};
#endif
#endif
//end

static struct i2c_driver tsc2007_driver = {
	.driver = {
		.owner	= THIS_MODULE,
		.name	= "tsc2007",
#ifdef CONFIG_PM
		.pm = &tsc2007_pm_ops,
		//.of_match_table = of_match_ptr(tsc2007_dt_match),
#endif
	},
	.id_table	= tsc2007_idtable,
	.probe		= tsc2007_probe,
	.remove		= tsc2007_remove,
};

module_i2c_driver(tsc2007_driver);

MODULE_AUTHOR("Kwangwoo Lee <kwlee@mtekvision.com>");
MODULE_DESCRIPTION("TSC2007 TouchScreen Driver");
MODULE_LICENSE("GPL");

/*
 * drivers/input/touchscreen/tsc2007.c
 *
 * Copyright (c) 2008 MtekVision Co., Ltd.
 *	Kwangwoo Lee <kwlee@mtekvision.com>
 *
 * Using code from:
 *  - ads7846.c
 *	Copyright (c) 2005 David Brownell
 *	Copyright (c) 2006 Nokia Corporation
 *  - corgi_ts.c
 *	Copyright (C) 2004-2005 Richard Purdie
 *  - omap_ts.[hc], ads7846.h, ts_osk.c
 *	Copyright (C) 2002 MontaVista Software
 *	Copyright (C) 2004 Texas Instruments
 *	Copyright (C) 2005 Dirk Behme
 *
 *  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/slab.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/i2c.h>
#include <linux/of_device.h>
#include <linux/of_gpio.h>
#include <linux/platform_data/tsc2007.h>
#include "tsc2007.h"

#undef dev_dbg
#define dev_dbg dev_err

int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
{
	s32 data;
	u16 val;

	data = i2c_smbus_read_word_data(tsc->client, cmd);
	if (data < 0) {
		dev_err(&tsc->client->dev, "i2c io error: %d\n", data);
		return data;
	}

	/* The protocol and raw data format from i2c interface:
	 * S Addr Wr [A] Comm [A] S Addr Rd [A] [DataLow] A [DataHigh] NA P
	 * Where DataLow has [D11-D4], DataHigh has [D3-D0 << 4 | Dummy 4bit].
	 */
	val = swab16(data) >> 4;

	dev_dbg(&tsc->client->dev, "data: 0x%x, val: 0x%x\n", data, val);

	return val;
}

static void tsc2007_read_values(struct tsc2007 *tsc, struct ts_event *tc)
{
	/* y- still on; turn on only y+ (and ADC) */
	tc->y = tsc2007_xfer(tsc, READ_Y);

	/* turn y- off, x+ on, then leave in lowpower */
	tc->x = tsc2007_xfer(tsc, READ_X);

	/* turn y+ off, x- on; we'll use formula #1 */
	tc->z1 = tsc2007_xfer(tsc, READ_Z1);
	tc->z2 = tsc2007_xfer(tsc, READ_Z2);

	/* Prepare for next touch reading - power down ADC, enable PENIRQ */
	tsc2007_xfer(tsc, PWRDOWN);
}

u32 tsc2007_calculate_resistance(struct tsc2007 *tsc, struct ts_event *tc)
{
	u32 rt = 0;

	/* range filtering */
	if (tc->x == MAX_12BIT)
		tc->x = 0;

	if (likely(tc->x && tc->z1)) {
		/* compute touch resistance using equation #1 */
		rt = tc->z2 - tc->z1;
		rt *= tc->x;
		rt *= tsc->x_plate_ohms;
		rt /= tc->z1;
		rt = (rt + 2047) >> 12;
	}

	return rt;
}

bool tsc2007_is_pen_down(struct tsc2007 *ts)
{
	/*
	 * NOTE: We can't rely on the pressure to determine the pen down
	 * state, even though this controller has a pressure sensor.
	 * The pressure value can fluctuate for quite a while after
	 * lifting the pen and in some cases may not even settle at the
	 * expected value.
	 *
	 * The only safe way to check for the pen up condition is in the
	 * work function by reading the pen signal state (it's a GPIO
	 * and IRQ). Unfortunately such callback is not always available,
	 * in that case we assume that the pen is down and expect caller
	 * to fall back on the pressure reading.
	 */

	if (!ts->get_pendown_state)
		return true;

	return ts->get_pendown_state(&ts->client->dev);
}

static irqreturn_t tsc2007_soft_irq(int irq, void *handle)
{
	struct tsc2007 *ts = handle;
	struct input_dev *input = ts->input;
	struct ts_event tc;
	u32 rt;

	while (!ts->stopped && tsc2007_is_pen_down(ts)) {

		/* pen is down, continue with the measurement */

		mutex_lock(&ts->mlock);
		tsc2007_read_values(ts, &tc);
		mutex_unlock(&ts->mlock);

		rt = tsc2007_calculate_resistance(ts, &tc);

		if (!rt && !ts->get_pendown_state) {
			/*
			 * If pressure reported is 0 and we don't have
			 * callback to check pendown state, we have to
			 * assume that pen was lifted up.
			 */
			break;
		}

		if (rt <= ts->max_rt) {
			dev_dbg(&ts->client->dev,
				"DOWN point(%4d,%4d), resistance (%4u)\n",
				tc.x, tc.y, rt);

			rt = ts->max_rt - rt;

			input_report_key(input, BTN_TOUCH, 1);
			input_report_abs(input, ABS_X, tc.x);
			input_report_abs(input, ABS_Y, tc.y);
			input_report_abs(input, ABS_PRESSURE, rt);

			input_sync(input);

		} else {
			/*
			 * Sample found inconsistent by debouncing or pressure is
			 * beyond the maximum. Don't report it to user space,
			 * repeat at least once more the measurement.
			 */
			dev_dbg(&ts->client->dev, "ignored pressure %d\n", rt);
		}

		wait_event_timeout(ts->wait, ts->stopped, ts->poll_period);
	}

	dev_dbg(&ts->client->dev, "UP\n");

	input_report_key(input, BTN_TOUCH, 0);
	input_report_abs(input, ABS_PRESSURE, 0);
	input_sync(input);

	if (ts->clear_penirq)
		ts->clear_penirq();

	return IRQ_HANDLED;
}

static irqreturn_t tsc2007_hard_irq(int irq, void *handle)
{
	struct tsc2007 *ts = handle;

	if (tsc2007_is_pen_down(ts))
		return IRQ_WAKE_THREAD;

	if (ts->clear_penirq)
		ts->clear_penirq();

	return IRQ_HANDLED;
}

static void tsc2007_stop(struct tsc2007 *ts)
{
	ts->stopped = true;
	mb();
	wake_up(&ts->wait);

	disable_irq(ts->irq);
}

static int tsc2007_open(struct input_dev *input_dev)
{
	struct tsc2007 *ts = input_get_drvdata(input_dev);
	int err;

	ts->stopped = false;
	mb();

	enable_irq(ts->irq);

	/* Prepare for touch readings - power down ADC and enable PENIRQ */
	err = tsc2007_xfer(ts, PWRDOWN);
	if (err < 0) {
		tsc2007_stop(ts);
		return err;
	}

	return 0;
}

static void tsc2007_close(struct input_dev *input_dev)
{
	struct tsc2007 *ts = input_get_drvdata(input_dev);

	tsc2007_stop(ts);
}

#ifdef CONFIG_OF
static int tsc2007_get_pendown_state_gpio(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct tsc2007 *ts = i2c_get_clientdata(client);

	return !gpio_get_value(ts->gpio);
}

static int tsc2007_probe_dt(struct i2c_client *client, struct tsc2007 *ts)
{
	struct device_node *np = client->dev.of_node;
	u32 val32;
	u64 val64;

	if (!np) {
		dev_err(&client->dev, "missing device tree data\n");
		return -EINVAL;
	}

	if (!of_property_read_u32(np, "ti,max-rt", &val32))
		ts->max_rt = val32;
	else
		ts->max_rt = MAX_12BIT;

	if (!of_property_read_u32(np, "ti,fuzzx", &val32))
		ts->fuzzx = val32;

	if (!of_property_read_u32(np, "ti,fuzzy", &val32))
		ts->fuzzy = val32;

	if (!of_property_read_u32(np, "ti,fuzzz", &val32))
		ts->fuzzz = val32;

	if (!of_property_read_u64(np, "ti,poll-period", &val64))
		ts->poll_period = msecs_to_jiffies(val64);
	else
		ts->poll_period = msecs_to_jiffies(1);

	if (!of_property_read_u32(np, "ti,x-plate-ohms", &val32)) {
		ts->x_plate_ohms = val32;
	} else {
		dev_err(&client->dev, "missing ti,x-plate-ohms devicetree property.");
		return -EINVAL;
	}

	ts->gpio = of_get_gpio(np, 0);
	if (gpio_is_valid(ts->gpio))
		ts->get_pendown_state = tsc2007_get_pendown_state_gpio;
	else
		dev_warn(&client->dev,
			 "GPIO not specified in DT (of_get_gpio returned %d)\n",
			 ts->gpio);

	return 0;
}
#else
static int tsc2007_probe_dt(struct i2c_client *client, struct tsc2007 *ts)
{
	dev_err(&client->dev, "platform data is required!\n");
	return -EINVAL;
}
#endif

static int tsc2007_probe_pdev(struct i2c_client *client, struct tsc2007 *ts,
			      const struct tsc2007_platform_data *pdata,
			      const struct i2c_device_id *id)
{
	ts->model             = pdata->model;
	ts->x_plate_ohms      = pdata->x_plate_ohms;
	ts->max_rt            = pdata->max_rt ? : MAX_12BIT;
	ts->poll_period       = msecs_to_jiffies(pdata->poll_period ? : 1);
	ts->get_pendown_state = pdata->get_pendown_state;
	ts->clear_penirq      = pdata->clear_penirq;
	ts->fuzzx             = pdata->fuzzx;
	ts->fuzzy             = pdata->fuzzy;
	ts->fuzzz             = pdata->fuzzz;

	if (pdata->x_plate_ohms == 0) {
		dev_err(&client->dev, "x_plate_ohms is not set up in platform data");
		return -EINVAL;
	}

	return 0;
}

static void tsc2007_call_exit_platform_hw(void *data)
{
	struct device *dev = data;
	const struct tsc2007_platform_data *pdata = dev_get_platdata(dev);

	pdata->exit_platform_hw();
}

static int tsc2007_probe(struct i2c_client *client,
			 const struct i2c_device_id *id)
{
	const struct tsc2007_platform_data *pdata =
		dev_get_platdata(&client->dev);
	struct tsc2007 *ts;
	struct input_dev *input_dev;
	int err;

	if (!i2c_check_functionality(client->adapter,
				     I2C_FUNC_SMBUS_READ_WORD_DATA))
		return -EIO;

	ts = devm_kzalloc(&client->dev, sizeof(struct tsc2007), GFP_KERNEL);
	if (!ts)
		return -ENOMEM;

	if (pdata)
		err = tsc2007_probe_pdev(client, ts, pdata, id);
	else
		err = tsc2007_probe_dt(client, ts);
	if (err)
		return err;

	input_dev = devm_input_allocate_device(&client->dev);
	if (!input_dev)
		return -ENOMEM;

	i2c_set_clientdata(client, ts);

	ts->client = client;
	ts->irq = client->irq;
	ts->input = input_dev;

	init_waitqueue_head(&ts->wait);
	mutex_init(&ts->mlock);

	snprintf(ts->phys, sizeof(ts->phys),
		 "%s/input0", dev_name(&client->dev));

	input_dev->name = "TSC2007 Touchscreen";
	input_dev->phys = ts->phys;
	input_dev->id.bustype = BUS_I2C;

	input_dev->open = tsc2007_open;
	input_dev->close = tsc2007_close;

	input_set_drvdata(input_dev, ts);

	input_set_capability(input_dev, EV_KEY, BTN_TOUCH);

	input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, ts->fuzzx, 0);
	input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, ts->fuzzy, 0);
	input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT,
			     ts->fuzzz, 0);

	if (pdata) {
		if (pdata->exit_platform_hw) {
			err = devm_add_action(&client->dev,
					      tsc2007_call_exit_platform_hw,
					      &client->dev);
			if (err) {
				dev_err(&client->dev,
					"Failed to register exit_platform_hw action, %d\n",
					err);
				return err;
			}
		}

		if (pdata->init_platform_hw)
			pdata->init_platform_hw();
	}

	err = devm_request_threaded_irq(&client->dev, ts->irq,
					tsc2007_hard_irq, tsc2007_soft_irq,
					IRQF_ONESHOT,
					client->dev.driver->name, ts);
	if (err) {
		dev_err(&client->dev, "Failed to request irq %d: %d\n",
			ts->irq, err);
		return err;
	}

	tsc2007_stop(ts);

	/* power down the chip (TSC2007_SETUP does not ACK on I2C) */
	err = tsc2007_xfer(ts, PWRDOWN);
	if (err < 0) {
		dev_err(&client->dev,
			"Failed to setup chip: %d\n", err);
		return err;	/* chip does not respond */
	}

	err = input_register_device(input_dev);
	if (err) {
		dev_err(&client->dev,
			"Failed to register input device: %d\n", err);
		return err;
	}

	err =  tsc2007_iio_configure(ts);
	if (err) {
		dev_err(&client->dev,
			"Failed to register with IIO: %d\n", err);
		return err;
	}

	return 0;
}

static const struct i2c_device_id tsc2007_idtable[] = {
	{ "tsc2007", 0 },
	{ }
};

MODULE_DEVICE_TABLE(i2c, tsc2007_idtable);

#ifdef CONFIG_OF
static const struct of_device_id tsc2007_of_match[] = {
	{ .compatible = "ti,tsc2007" },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, tsc2007_of_match);
#endif

static struct i2c_driver tsc2007_driver = {
	.driver = {
		.name	= "tsc2007",
		.of_match_table = of_match_ptr(tsc2007_of_match),
	},
	.id_table	= tsc2007_idtable,
	.probe		= tsc2007_probe,
};

module_i2c_driver(tsc2007_driver);

MODULE_AUTHOR("Kwangwoo Lee <kwlee@mtekvision.com>");
MODULE_DESCRIPTION("TSC2007 TouchScreen Driver");
MODULE_LICENSE("GPL");

/*
 * Copyright (c) 2016 Golden Delicious Comp. GmbH&Co. KG
 *	Nikolaus Schaller <hns@goldelico.com>
 *
 *  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/i2c.h>
#include <linux/iio/iio.h>
#include "tsc2007.h"

struct tsc2007_iio {
	struct tsc2007 *ts;
};

#define TSC2007_CHAN_IIO(_chan, _name, _type, _chan_info) \
{ \
	.datasheet_name = _name, \
	.type = _type, \
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |	\
			BIT(_chan_info), \
	.indexed = 1, \
	.channel = _chan, \
}

static const struct iio_chan_spec tsc2007_iio_channel[] = {
	TSC2007_CHAN_IIO(0, "x", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
	TSC2007_CHAN_IIO(1, "y", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
	TSC2007_CHAN_IIO(2, "z1", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
	TSC2007_CHAN_IIO(3, "z2", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
	TSC2007_CHAN_IIO(4, "adc", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
	TSC2007_CHAN_IIO(5, "rt", IIO_VOLTAGE, IIO_CHAN_INFO_RAW), /* Ohms? */
	TSC2007_CHAN_IIO(6, "pen", IIO_PRESSURE, IIO_CHAN_INFO_RAW),
	TSC2007_CHAN_IIO(7, "temp0", IIO_TEMP, IIO_CHAN_INFO_RAW),
	TSC2007_CHAN_IIO(8, "temp1", IIO_TEMP, IIO_CHAN_INFO_RAW),
};

static int tsc2007_read_raw(struct iio_dev *indio_dev,
			    struct iio_chan_spec const *chan,
			    int *val, int *val2, long mask)
{
	struct tsc2007_iio *iio = iio_priv(indio_dev);
	struct tsc2007 *tsc = iio->ts;
	int adc_chan = chan->channel;
	int ret = 0;

	if (adc_chan >= ARRAY_SIZE(tsc2007_iio_channel))
		return -EINVAL;

	if (mask != IIO_CHAN_INFO_RAW)
		return -EINVAL;

	mutex_lock(&tsc->mlock);

	switch (chan->channel) {
	case 0:
		*val = tsc2007_xfer(tsc, READ_X);
		break;
	case 1:
		*val = tsc2007_xfer(tsc, READ_Y);
		break;
	case 2:
		*val = tsc2007_xfer(tsc, READ_Z1);
		break;
	case 3:
		*val = tsc2007_xfer(tsc, READ_Z2);
		break;
	case 4:
		*val = tsc2007_xfer(tsc, (ADC_ON_12BIT | TSC2007_MEASURE_AUX));
		break;
	case 5: {
		struct ts_event tc;

		tc.x = tsc2007_xfer(tsc, READ_X);
		tc.z1 = tsc2007_xfer(tsc, READ_Z1);
		tc.z2 = tsc2007_xfer(tsc, READ_Z2);
		*val = tsc2007_calculate_resistance(tsc, &tc);
		break;
	}
	case 6:
		*val = tsc2007_is_pen_down(tsc);
		break;
	case 7:
		*val = tsc2007_xfer(tsc,
				    (ADC_ON_12BIT | TSC2007_MEASURE_TEMP0));
		break;
	case 8:
		*val = tsc2007_xfer(tsc,
				    (ADC_ON_12BIT | TSC2007_MEASURE_TEMP1));
		break;
	}

	/* Prepare for next touch reading - power down ADC, enable PENIRQ */
	tsc2007_xfer(tsc, PWRDOWN);

	mutex_unlock(&tsc->mlock);

	ret = IIO_VAL_INT;

	return ret;
}

static const struct iio_info tsc2007_iio_info = {
	.read_raw = tsc2007_read_raw,
};

int tsc2007_iio_configure(struct tsc2007 *ts)
{
	struct iio_dev *indio_dev;
	struct tsc2007_iio *iio;
	int error;

	indio_dev = devm_iio_device_alloc(&ts->client->dev, sizeof(*iio));
	if (!indio_dev) {
		dev_err(&ts->client->dev, "iio_device_alloc failed\n");
		return -ENOMEM;
	}

	iio = iio_priv(indio_dev);
	iio->ts = ts;

	indio_dev->name = "tsc2007";
	indio_dev->dev.parent = &ts->client->dev;
	indio_dev->info = &tsc2007_iio_info;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->channels = tsc2007_iio_channel;
	indio_dev->num_channels = ARRAY_SIZE(tsc2007_iio_channel);

	error = devm_iio_device_register(&ts->client->dev, indio_dev);
	if (error) {
		dev_err(&ts->client->dev,
			"iio_device_register() failed: %d\n", error);
		return error;
	}

	return 0;
}