drivers/input/touchscreen/ucb1400_ts.c - arm/linux-arm64-legacy - Git at Google

 /*
  *  Philips UCB1400 touchscreen driver
  *
  *  Author:	Nicolas Pitre
  *  Created:	September 25, 2006
  *  Copyright:	MontaVista Software, Inc.
  *
  * Spliting done by: Marek Vasut <marek.vasut@gmail.com>
  * If something doesn't work and it worked before spliting, e-mail me,
  * dont bother Nicolas please ;-)
  *
  * 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.
  *
  * This code is heavily based on ucb1x00-*.c copyrighted by Russell King
  * covering the UCB1100, UCB1200 and UCB1300..  Support for the UCB1400 has
  * been made separate from ucb1x00-core/ucb1x00-ts on Russell's request.
  */

 #include <linux/module.h>
 #include <linux/delay.h>
 #include <linux/sched.h>
 #include <linux/wait.h>
 #include <linux/input.h>
 #include <linux/device.h>
 #include <linux/interrupt.h>
 #include <linux/ucb1400.h>

 #define UCB1400_TS_POLL_PERIOD	10 /* ms */

 static bool adcsync;
 static int ts_delay = 55; /* us */
 static int ts_delay_pressure;	/* us */

 /* Switch to interrupt mode. */
 static void ucb1400_ts_mode_int(struct ucb1400_ts *ucb)
 {
 	ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
 			UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW |
 			UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |
 			UCB_TS_CR_MODE_INT);
 }

 /*
  * Switch to pressure mode, and read pressure.  We don't need to wait
  * here, since both plates are being driven.
  */
 static unsigned int ucb1400_ts_read_pressure(struct ucb1400_ts *ucb)
 {
 	ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
 			UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW |
 			UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |
 			UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);

 	udelay(ts_delay_pressure);

 	return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPY, adcsync);
 }

 /*
  * Switch to X position mode and measure Y plate.  We switch the plate
  * configuration in pressure mode, then switch to position mode.  This
  * gives a faster response time.  Even so, we need to wait about 55us
  * for things to stabilise.
  */
 static unsigned int ucb1400_ts_read_xpos(struct ucb1400_ts *ucb)
 {
 	ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
 			UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
 			UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
 	ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
 			UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
 			UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
 	ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
 			UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
 			UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);

 	udelay(ts_delay);

 	return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPY, adcsync);
 }

 /*
  * Switch to Y position mode and measure X plate.  We switch the plate
  * configuration in pressure mode, then switch to position mode.  This
  * gives a faster response time.  Even so, we need to wait about 55us
  * for things to stabilise.
  */
 static int ucb1400_ts_read_ypos(struct ucb1400_ts *ucb)
 {
 	ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
 			UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
 			UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
 	ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
 			UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
 			UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
 	ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
 			UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
 			UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);

 	udelay(ts_delay);

 	return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPX, adcsync);
 }

 /*
  * Switch to X plate resistance mode.  Set MX to ground, PX to
  * supply.  Measure current.
  */
 static unsigned int ucb1400_ts_read_xres(struct ucb1400_ts *ucb)
 {
 	ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
 			UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
 			UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
 	return ucb1400_adc_read(ucb->ac97, 0, adcsync);
 }

 /*
  * Switch to Y plate resistance mode.  Set MY to ground, PY to
  * supply.  Measure current.
  */
 static unsigned int ucb1400_ts_read_yres(struct ucb1400_ts *ucb)
 {
 	ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
 			UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
 			UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
 	return ucb1400_adc_read(ucb->ac97, 0, adcsync);
 }

 static int ucb1400_ts_pen_up(struct ucb1400_ts *ucb)
 {
 	unsigned short val = ucb1400_reg_read(ucb->ac97, UCB_TS_CR);

 	return val & (UCB_TS_CR_TSPX_LOW | UCB_TS_CR_TSMX_LOW);
 }

 static void ucb1400_ts_irq_enable(struct ucb1400_ts *ucb)
 {
 	ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, UCB_IE_TSPX);
 	ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);
 	ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, UCB_IE_TSPX);
 }

 static void ucb1400_ts_irq_disable(struct ucb1400_ts *ucb)
 {
 	ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, 0);
 }

 static void ucb1400_ts_report_event(struct input_dev *idev, u16 pressure, u16 x, u16 y)
 {
 	input_report_abs(idev, ABS_X, x);
 	input_report_abs(idev, ABS_Y, y);
 	input_report_abs(idev, ABS_PRESSURE, pressure);
 	input_report_key(idev, BTN_TOUCH, 1);
 	input_sync(idev);
 }

 static void ucb1400_ts_event_release(struct input_dev *idev)
 {
 	input_report_abs(idev, ABS_PRESSURE, 0);
 	input_report_key(idev, BTN_TOUCH, 0);
 	input_sync(idev);
 }

 static void ucb1400_clear_pending_irq(struct ucb1400_ts *ucb)
 {
 	unsigned int isr;

 	isr = ucb1400_reg_read(ucb->ac97, UCB_IE_STATUS);
 	ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, isr);
 	ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);

 	if (isr & UCB_IE_TSPX)
 		ucb1400_ts_irq_disable(ucb);
 	else
 		dev_dbg(&ucb->ts_idev->dev,
 			"ucb1400: unexpected IE_STATUS = %#x\n", isr);
 }

 /*
  * A restriction with interrupts exists when using the ucb1400, as
  * the codec read/write routines may sleep while waiting for codec
  * access completion and uses semaphores for access control to the
  * AC97 bus. Therefore the driver is forced to use threaded interrupt
  * handler.
  */
 static irqreturn_t ucb1400_irq(int irqnr, void *devid)
 {
 	struct ucb1400_ts *ucb = devid;
 	unsigned int x, y, p;
 	bool penup;

 	if (unlikely(irqnr != ucb->irq))
 		return IRQ_NONE;

 	ucb1400_clear_pending_irq(ucb);

 	/* Start with a small delay before checking pendown state */
 	msleep(UCB1400_TS_POLL_PERIOD);

 	while (!ucb->stopped && !(penup = ucb1400_ts_pen_up(ucb))) {

 		ucb1400_adc_enable(ucb->ac97);
 		x = ucb1400_ts_read_xpos(ucb);
 		y = ucb1400_ts_read_ypos(ucb);
 		p = ucb1400_ts_read_pressure(ucb);
 		ucb1400_adc_disable(ucb->ac97);

 		ucb1400_ts_report_event(ucb->ts_idev, p, x, y);

 		wait_event_timeout(ucb->ts_wait, ucb->stopped,
 				   msecs_to_jiffies(UCB1400_TS_POLL_PERIOD));
 	}

 	ucb1400_ts_event_release(ucb->ts_idev);

 	if (!ucb->stopped) {
 		/* Switch back to interrupt mode. */
 		ucb1400_ts_mode_int(ucb);
 		ucb1400_ts_irq_enable(ucb);
 	}

 	return IRQ_HANDLED;
 }

 static void ucb1400_ts_stop(struct ucb1400_ts *ucb)
 {
 	/* Signal IRQ thread to stop polling and disable the handler. */
 	ucb->stopped = true;
 	mb();
 	wake_up(&ucb->ts_wait);
 	disable_irq(ucb->irq);

 	ucb1400_ts_irq_disable(ucb);
 	ucb1400_reg_write(ucb->ac97, UCB_TS_CR, 0);
 }

 /* Must be called with ts->lock held */
 static void ucb1400_ts_start(struct ucb1400_ts *ucb)
 {
 	/* Tell IRQ thread that it may poll the device. */
 	ucb->stopped = false;
 	mb();

 	ucb1400_ts_mode_int(ucb);
 	ucb1400_ts_irq_enable(ucb);

 	enable_irq(ucb->irq);
 }

 static int ucb1400_ts_open(struct input_dev *idev)
 {
 	struct ucb1400_ts *ucb = input_get_drvdata(idev);

 	ucb1400_ts_start(ucb);

 	return 0;
 }

 static void ucb1400_ts_close(struct input_dev *idev)
 {
 	struct ucb1400_ts *ucb = input_get_drvdata(idev);

 	ucb1400_ts_stop(ucb);
 }

 #ifndef NO_IRQ
 #define NO_IRQ	0
 #endif

 /*
  * Try to probe our interrupt, rather than relying on lots of
  * hard-coded machine dependencies.
  */
 static int ucb1400_ts_detect_irq(struct ucb1400_ts *ucb,
 					   struct platform_device *pdev)
 {
 	unsigned long mask, timeout;

 	mask = probe_irq_on();

 	/* Enable the ADC interrupt. */
 	ucb1400_reg_write(ucb->ac97, UCB_IE_RIS, UCB_IE_ADC);
 	ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, UCB_IE_ADC);
 	ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0xffff);
 	ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);

 	/* Cause an ADC interrupt. */
 	ucb1400_reg_write(ucb->ac97, UCB_ADC_CR, UCB_ADC_ENA);
 	ucb1400_reg_write(ucb->ac97, UCB_ADC_CR, UCB_ADC_ENA | UCB_ADC_START);

 	/* Wait for the conversion to complete. */
 	timeout = jiffies + HZ/2;
 	while (!(ucb1400_reg_read(ucb->ac97, UCB_ADC_DATA) &
 						UCB_ADC_DAT_VALID)) {
 		cpu_relax();
 		if (time_after(jiffies, timeout)) {
 			dev_err(&pdev->dev, "timed out in IRQ probe\n");
 			probe_irq_off(mask);
 			return -ENODEV;
 		}
 	}
 	ucb1400_reg_write(ucb->ac97, UCB_ADC_CR, 0);

 	/* Disable and clear interrupt. */
 	ucb1400_reg_write(ucb->ac97, UCB_IE_RIS, 0);
 	ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, 0);
 	ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0xffff);
 	ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);

 	/* Read triggered interrupt. */
 	ucb->irq = probe_irq_off(mask);
 	if (ucb->irq < 0 || ucb->irq == NO_IRQ)
 		return -ENODEV;

 	return 0;
 }

 static int ucb1400_ts_probe(struct platform_device *pdev)
 {
 	struct ucb1400_ts *ucb = dev_get_platdata(&pdev->dev);
 	int error, x_res, y_res;
 	u16 fcsr;

 	ucb->ts_idev = input_allocate_device();
 	if (!ucb->ts_idev) {
 		error = -ENOMEM;
 		goto err;
 	}

 	/* Only in case the IRQ line wasn't supplied, try detecting it */
 	if (ucb->irq < 0) {
 		error = ucb1400_ts_detect_irq(ucb, pdev);
 		if (error) {
 			dev_err(&pdev->dev, "IRQ probe failed\n");
 			goto err_free_devs;
 		}
 	}
 	dev_dbg(&pdev->dev, "found IRQ %d\n", ucb->irq);

 	init_waitqueue_head(&ucb->ts_wait);

 	input_set_drvdata(ucb->ts_idev, ucb);

 	ucb->ts_idev->dev.parent	= &pdev->dev;
 	ucb->ts_idev->name		= "UCB1400 touchscreen interface";
 	ucb->ts_idev->id.vendor		= ucb1400_reg_read(ucb->ac97,
 						AC97_VENDOR_ID1);
 	ucb->ts_idev->id.product	= ucb->id;
 	ucb->ts_idev->open		= ucb1400_ts_open;
 	ucb->ts_idev->close		= ucb1400_ts_close;
 	ucb->ts_idev->evbit[0]		= BIT_MASK(EV_ABS) | BIT_MASK(EV_KEY);
 	ucb->ts_idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);

 	/*
 	 * Enable ADC filter to prevent horrible jitter on Colibri.
 	 * This also further reduces jitter on boards where ADCSYNC
 	 * pin is connected.
 	 */
 	fcsr = ucb1400_reg_read(ucb->ac97, UCB_FCSR);
 	ucb1400_reg_write(ucb->ac97, UCB_FCSR, fcsr | UCB_FCSR_AVE);

 	ucb1400_adc_enable(ucb->ac97);
 	x_res = ucb1400_ts_read_xres(ucb);
 	y_res = ucb1400_ts_read_yres(ucb);
 	ucb1400_adc_disable(ucb->ac97);
 	dev_dbg(&pdev->dev, "x/y = %d/%d\n", x_res, y_res);

 	input_set_abs_params(ucb->ts_idev, ABS_X, 0, x_res, 0, 0);
 	input_set_abs_params(ucb->ts_idev, ABS_Y, 0, y_res, 0, 0);
 	input_set_abs_params(ucb->ts_idev, ABS_PRESSURE, 0, 0, 0, 0);

 	ucb1400_ts_stop(ucb);

 	error = request_threaded_irq(ucb->irq, NULL, ucb1400_irq,
 				     IRQF_TRIGGER_RISING | IRQF_ONESHOT,
 				     "UCB1400", ucb);
 	if (error) {
 		dev_err(&pdev->dev,
 			"unable to grab irq%d: %d\n", ucb->irq, error);
 		goto err_free_devs;
 	}

 	error = input_register_device(ucb->ts_idev);
 	if (error)
 		goto err_free_irq;

 	return 0;

 err_free_irq:
 	free_irq(ucb->irq, ucb);
 err_free_devs:
 	input_free_device(ucb->ts_idev);
 err:
 	return error;
 }

 static int ucb1400_ts_remove(struct platform_device *pdev)
 {
 	struct ucb1400_ts *ucb = dev_get_platdata(&pdev->dev);

 	free_irq(ucb->irq, ucb);
 	input_unregister_device(ucb->ts_idev);

 	return 0;
 }

 #ifdef CONFIG_PM_SLEEP
 static int ucb1400_ts_suspend(struct device *dev)
 {
 	struct ucb1400_ts *ucb = dev_get_platdata(dev);
 	struct input_dev *idev = ucb->ts_idev;

 	mutex_lock(&idev->mutex);

 	if (idev->users)
 		ucb1400_ts_start(ucb);

 	mutex_unlock(&idev->mutex);
 	return 0;
 }

 static int ucb1400_ts_resume(struct device *dev)
 {
 	struct ucb1400_ts *ucb = dev_get_platdata(dev);
 	struct input_dev *idev = ucb->ts_idev;

 	mutex_lock(&idev->mutex);

 	if (idev->users)
 		ucb1400_ts_stop(ucb);

 	mutex_unlock(&idev->mutex);
 	return 0;
 }
 #endif

 static SIMPLE_DEV_PM_OPS(ucb1400_ts_pm_ops,
 			 ucb1400_ts_suspend, ucb1400_ts_resume);

 static struct platform_driver ucb1400_ts_driver = {
 	.probe	= ucb1400_ts_probe,
 	.remove	= ucb1400_ts_remove,
 	.driver	= {
 		.name	= "ucb1400_ts",
 		.owner	= THIS_MODULE,
 		.pm	= &ucb1400_ts_pm_ops,
 	},
 };
 module_platform_driver(ucb1400_ts_driver);

 module_param(adcsync, bool, 0444);
 MODULE_PARM_DESC(adcsync, "Synchronize touch readings with ADCSYNC pin.");

 module_param(ts_delay, int, 0444);
 MODULE_PARM_DESC(ts_delay, "Delay between panel setup and"
 			    " position read. Default = 55us.");

 module_param(ts_delay_pressure, int, 0444);
 MODULE_PARM_DESC(ts_delay_pressure,
 		"delay between panel setup and pressure read."
 		"  Default = 0us.");

 MODULE_DESCRIPTION("Philips UCB1400 touchscreen driver");
 MODULE_LICENSE("GPL");
	/*
	* Philips UCB1400 touchscreen driver
	*
	* Author: Nicolas Pitre
	* Created: September 25, 2006
	* Copyright: MontaVista Software, Inc.
	*
	* Spliting done by: Marek Vasut <marek.vasut@gmail.com>
	* If something doesn't work and it worked before spliting, e-mail me,
	* dont bother Nicolas please ;-)
	*
	* 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.
	*
	* This code is heavily based on ucb1x00-*.c copyrighted by Russell King
	* covering the UCB1100, UCB1200 and UCB1300.. Support for the UCB1400 has
	* been made separate from ucb1x00-core/ucb1x00-ts on Russell's request.
	*/

	#include <linux/module.h>
	#include <linux/delay.h>
	#include <linux/sched.h>
	#include <linux/wait.h>
	#include <linux/input.h>
	#include <linux/device.h>
	#include <linux/interrupt.h>
	#include <linux/ucb1400.h>

	#define UCB1400_TS_POLL_PERIOD 10 /* ms */

	static bool adcsync;
	static int ts_delay = 55; /* us */
	static int ts_delay_pressure; /* us */

	/* Switch to interrupt mode. */
	static void ucb1400_ts_mode_int(struct ucb1400_ts *ucb)
	{
	ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
	UCB_TS_CR_TSMX_POW \| UCB_TS_CR_TSPX_POW \|
	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_GND \|
	UCB_TS_CR_MODE_INT);
	}

	/*
	* Switch to pressure mode, and read pressure. We don't need to wait
	* here, since both plates are being driven.
	*/
	static unsigned int ucb1400_ts_read_pressure(struct ucb1400_ts *ucb)
	{
	ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
	UCB_TS_CR_TSMX_POW \| UCB_TS_CR_TSPX_POW \|
	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_GND \|
	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);

	udelay(ts_delay_pressure);

	return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPY, adcsync);
	}

	/*
	* Switch to X position mode and measure Y plate. We switch the plate
	* configuration in pressure mode, then switch to position mode. This
	* gives a faster response time. Even so, we need to wait about 55us
	* for things to stabilise.
	*/
	static unsigned int ucb1400_ts_read_xpos(struct ucb1400_ts *ucb)
	{
	ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
	UCB_TS_CR_TSMX_GND \| UCB_TS_CR_TSPX_POW \|
	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
	ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
	UCB_TS_CR_TSMX_GND \| UCB_TS_CR_TSPX_POW \|
	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
	ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
	UCB_TS_CR_TSMX_GND \| UCB_TS_CR_TSPX_POW \|
	UCB_TS_CR_MODE_POS \| UCB_TS_CR_BIAS_ENA);

	udelay(ts_delay);

	return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPY, adcsync);
	}

	/*
	* Switch to Y position mode and measure X plate. We switch the plate
	* configuration in pressure mode, then switch to position mode. This
	* gives a faster response time. Even so, we need to wait about 55us
	* for things to stabilise.
	*/
	static int ucb1400_ts_read_ypos(struct ucb1400_ts *ucb)
	{
	ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_POW \|
	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
	ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_POW \|
	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
	ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_POW \|
	UCB_TS_CR_MODE_POS \| UCB_TS_CR_BIAS_ENA);

	udelay(ts_delay);

	return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPX, adcsync);
	}

	/*
	* Switch to X plate resistance mode. Set MX to ground, PX to
	* supply. Measure current.
	*/
	static unsigned int ucb1400_ts_read_xres(struct ucb1400_ts *ucb)
	{
	ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
	UCB_TS_CR_TSMX_GND \| UCB_TS_CR_TSPX_POW \|
	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
	return ucb1400_adc_read(ucb->ac97, 0, adcsync);
	}

	/*
	* Switch to Y plate resistance mode. Set MY to ground, PY to
	* supply. Measure current.
	*/
	static unsigned int ucb1400_ts_read_yres(struct ucb1400_ts *ucb)
	{
	ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_POW \|
	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
	return ucb1400_adc_read(ucb->ac97, 0, adcsync);
	}

	static int ucb1400_ts_pen_up(struct ucb1400_ts *ucb)
	{
	unsigned short val = ucb1400_reg_read(ucb->ac97, UCB_TS_CR);

	return val & (UCB_TS_CR_TSPX_LOW \| UCB_TS_CR_TSMX_LOW);
	}

	static void ucb1400_ts_irq_enable(struct ucb1400_ts *ucb)
	{
	ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, UCB_IE_TSPX);
	ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);
	ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, UCB_IE_TSPX);
	}

	static void ucb1400_ts_irq_disable(struct ucb1400_ts *ucb)
	{
	ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, 0);
	}

	static void ucb1400_ts_report_event(struct input_dev *idev, u16 pressure, u16 x, u16 y)
	{
	input_report_abs(idev, ABS_X, x);
	input_report_abs(idev, ABS_Y, y);
	input_report_abs(idev, ABS_PRESSURE, pressure);
	input_report_key(idev, BTN_TOUCH, 1);
	input_sync(idev);
	}

	static void ucb1400_ts_event_release(struct input_dev *idev)
	{
	input_report_abs(idev, ABS_PRESSURE, 0);
	input_report_key(idev, BTN_TOUCH, 0);
	input_sync(idev);
	}

	static void ucb1400_clear_pending_irq(struct ucb1400_ts *ucb)
	{
	unsigned int isr;

	isr = ucb1400_reg_read(ucb->ac97, UCB_IE_STATUS);
	ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, isr);
	ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);

	if (isr & UCB_IE_TSPX)
	ucb1400_ts_irq_disable(ucb);
	else
	dev_dbg(&ucb->ts_idev->dev,
	"ucb1400: unexpected IE_STATUS = %#x\n", isr);
	}

	/*
	* A restriction with interrupts exists when using the ucb1400, as
	* the codec read/write routines may sleep while waiting for codec
	* access completion and uses semaphores for access control to the
	* AC97 bus. Therefore the driver is forced to use threaded interrupt
	* handler.
	*/
	static irqreturn_t ucb1400_irq(int irqnr, void *devid)
	{
	struct ucb1400_ts *ucb = devid;
	unsigned int x, y, p;
	bool penup;

	if (unlikely(irqnr != ucb->irq))
	return IRQ_NONE;

	ucb1400_clear_pending_irq(ucb);

	/* Start with a small delay before checking pendown state */
	msleep(UCB1400_TS_POLL_PERIOD);

	while (!ucb->stopped && !(penup = ucb1400_ts_pen_up(ucb))) {

	ucb1400_adc_enable(ucb->ac97);
	x = ucb1400_ts_read_xpos(ucb);
	y = ucb1400_ts_read_ypos(ucb);
	p = ucb1400_ts_read_pressure(ucb);
	ucb1400_adc_disable(ucb->ac97);

	ucb1400_ts_report_event(ucb->ts_idev, p, x, y);

	wait_event_timeout(ucb->ts_wait, ucb->stopped,
	msecs_to_jiffies(UCB1400_TS_POLL_PERIOD));
	}

	ucb1400_ts_event_release(ucb->ts_idev);

	if (!ucb->stopped) {
	/* Switch back to interrupt mode. */
	ucb1400_ts_mode_int(ucb);
	ucb1400_ts_irq_enable(ucb);
	}

	return IRQ_HANDLED;
	}

	static void ucb1400_ts_stop(struct ucb1400_ts *ucb)
	{
	/* Signal IRQ thread to stop polling and disable the handler. */
	ucb->stopped = true;
	mb();
	wake_up(&ucb->ts_wait);
	disable_irq(ucb->irq);

	ucb1400_ts_irq_disable(ucb);
	ucb1400_reg_write(ucb->ac97, UCB_TS_CR, 0);
	}

	/* Must be called with ts->lock held */
	static void ucb1400_ts_start(struct ucb1400_ts *ucb)
	{
	/* Tell IRQ thread that it may poll the device. */
	ucb->stopped = false;
	mb();

	ucb1400_ts_mode_int(ucb);
	ucb1400_ts_irq_enable(ucb);

	enable_irq(ucb->irq);
	}

	static int ucb1400_ts_open(struct input_dev *idev)
	{
	struct ucb1400_ts *ucb = input_get_drvdata(idev);

	ucb1400_ts_start(ucb);

	return 0;
	}

	static void ucb1400_ts_close(struct input_dev *idev)
	{
	struct ucb1400_ts *ucb = input_get_drvdata(idev);

	ucb1400_ts_stop(ucb);
	}

	#ifndef NO_IRQ
	#define NO_IRQ 0
	#endif

	/*
	* Try to probe our interrupt, rather than relying on lots of
	* hard-coded machine dependencies.
	*/
	static int ucb1400_ts_detect_irq(struct ucb1400_ts *ucb,
	struct platform_device *pdev)
	{
	unsigned long mask, timeout;

	mask = probe_irq_on();

	/* Enable the ADC interrupt. */
	ucb1400_reg_write(ucb->ac97, UCB_IE_RIS, UCB_IE_ADC);
	ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, UCB_IE_ADC);
	ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0xffff);
	ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);

	/* Cause an ADC interrupt. */
	ucb1400_reg_write(ucb->ac97, UCB_ADC_CR, UCB_ADC_ENA);
	ucb1400_reg_write(ucb->ac97, UCB_ADC_CR, UCB_ADC_ENA \| UCB_ADC_START);

	/* Wait for the conversion to complete. */
	timeout = jiffies + HZ/2;
	while (!(ucb1400_reg_read(ucb->ac97, UCB_ADC_DATA) &
	UCB_ADC_DAT_VALID)) {
	cpu_relax();
	if (time_after(jiffies, timeout)) {
	dev_err(&pdev->dev, "timed out in IRQ probe\n");
	probe_irq_off(mask);
	return -ENODEV;
	}
	}
	ucb1400_reg_write(ucb->ac97, UCB_ADC_CR, 0);

	/* Disable and clear interrupt. */
	ucb1400_reg_write(ucb->ac97, UCB_IE_RIS, 0);
	ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, 0);
	ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0xffff);
	ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);

	/* Read triggered interrupt. */
	ucb->irq = probe_irq_off(mask);
	if (ucb->irq < 0 \|\| ucb->irq == NO_IRQ)
	return -ENODEV;

	return 0;
	}

	static int ucb1400_ts_probe(struct platform_device *pdev)
	{
	struct ucb1400_ts *ucb = dev_get_platdata(&pdev->dev);
	int error, x_res, y_res;
	u16 fcsr;

	ucb->ts_idev = input_allocate_device();
	if (!ucb->ts_idev) {
	error = -ENOMEM;
	goto err;
	}

	/* Only in case the IRQ line wasn't supplied, try detecting it */
	if (ucb->irq < 0) {
	error = ucb1400_ts_detect_irq(ucb, pdev);
	if (error) {
	dev_err(&pdev->dev, "IRQ probe failed\n");
	goto err_free_devs;
	}
	}
	dev_dbg(&pdev->dev, "found IRQ %d\n", ucb->irq);

	init_waitqueue_head(&ucb->ts_wait);

	input_set_drvdata(ucb->ts_idev, ucb);

	ucb->ts_idev->dev.parent = &pdev->dev;
	ucb->ts_idev->name = "UCB1400 touchscreen interface";
	ucb->ts_idev->id.vendor = ucb1400_reg_read(ucb->ac97,
	AC97_VENDOR_ID1);
	ucb->ts_idev->id.product = ucb->id;
	ucb->ts_idev->open = ucb1400_ts_open;
	ucb->ts_idev->close = ucb1400_ts_close;
	ucb->ts_idev->evbit[0] = BIT_MASK(EV_ABS) \| BIT_MASK(EV_KEY);
	ucb->ts_idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);

	/*
	* Enable ADC filter to prevent horrible jitter on Colibri.
	* This also further reduces jitter on boards where ADCSYNC
	* pin is connected.
	*/
	fcsr = ucb1400_reg_read(ucb->ac97, UCB_FCSR);
	ucb1400_reg_write(ucb->ac97, UCB_FCSR, fcsr \| UCB_FCSR_AVE);

	ucb1400_adc_enable(ucb->ac97);
	x_res = ucb1400_ts_read_xres(ucb);
	y_res = ucb1400_ts_read_yres(ucb);
	ucb1400_adc_disable(ucb->ac97);
	dev_dbg(&pdev->dev, "x/y = %d/%d\n", x_res, y_res);

	input_set_abs_params(ucb->ts_idev, ABS_X, 0, x_res, 0, 0);
	input_set_abs_params(ucb->ts_idev, ABS_Y, 0, y_res, 0, 0);
	input_set_abs_params(ucb->ts_idev, ABS_PRESSURE, 0, 0, 0, 0);

	ucb1400_ts_stop(ucb);

	error = request_threaded_irq(ucb->irq, NULL, ucb1400_irq,
	IRQF_TRIGGER_RISING \| IRQF_ONESHOT,
	"UCB1400", ucb);
	if (error) {
	dev_err(&pdev->dev,
	"unable to grab irq%d: %d\n", ucb->irq, error);
	goto err_free_devs;
	}

	error = input_register_device(ucb->ts_idev);
	if (error)
	goto err_free_irq;

	return 0;

	err_free_irq:
	free_irq(ucb->irq, ucb);
	err_free_devs:
	input_free_device(ucb->ts_idev);
	err:
	return error;
	}

	static int ucb1400_ts_remove(struct platform_device *pdev)
	{
	struct ucb1400_ts *ucb = dev_get_platdata(&pdev->dev);

	free_irq(ucb->irq, ucb);
	input_unregister_device(ucb->ts_idev);

	return 0;
	}

	#ifdef CONFIG_PM_SLEEP
	static int ucb1400_ts_suspend(struct device *dev)
	{
	struct ucb1400_ts *ucb = dev_get_platdata(dev);
	struct input_dev *idev = ucb->ts_idev;

	mutex_lock(&idev->mutex);

	if (idev->users)
	ucb1400_ts_start(ucb);

	mutex_unlock(&idev->mutex);
	return 0;
	}

	static int ucb1400_ts_resume(struct device *dev)
	{
	struct ucb1400_ts *ucb = dev_get_platdata(dev);
	struct input_dev *idev = ucb->ts_idev;

	mutex_lock(&idev->mutex);

	if (idev->users)
	ucb1400_ts_stop(ucb);

	mutex_unlock(&idev->mutex);
	return 0;
	}
	#endif

	static SIMPLE_DEV_PM_OPS(ucb1400_ts_pm_ops,
	ucb1400_ts_suspend, ucb1400_ts_resume);

	static struct platform_driver ucb1400_ts_driver = {
	.probe = ucb1400_ts_probe,
	.remove = ucb1400_ts_remove,
	.driver = {
	.name = "ucb1400_ts",
	.owner = THIS_MODULE,
	.pm = &ucb1400_ts_pm_ops,
	},
	};
	module_platform_driver(ucb1400_ts_driver);

	module_param(adcsync, bool, 0444);
	MODULE_PARM_DESC(adcsync, "Synchronize touch readings with ADCSYNC pin.");

	module_param(ts_delay, int, 0444);
	MODULE_PARM_DESC(ts_delay, "Delay between panel setup and"
	" position read. Default = 55us.");

	module_param(ts_delay_pressure, int, 0444);
	MODULE_PARM_DESC(ts_delay_pressure,
	"delay between panel setup and pressure read."
	" Default = 0us.");

	MODULE_DESCRIPTION("Philips UCB1400 touchscreen driver");
	MODULE_LICENSE("GPL");