[mirror_ubuntu-focal-kernel.git] / drivers / mfd / ucb1x00-ts.c

/*
 *  Touchscreen driver for UCB1x00-based touchscreens
 *
 *  Copyright (C) 2001 Russell King, All Rights Reserved.
 *  Copyright (C) 2005 Pavel Machek
 *
 * 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.
 *
 * 21-Jan-2002 <jco@ict.es> :
 *
 * Added support for synchronous A/D mode. This mode is useful to
 * avoid noise induced in the touchpanel by the LCD, provided that
 * the UCB1x00 has a valid LCD sync signal routed to its ADCSYNC pin.
 * It is important to note that the signal connected to the ADCSYNC
 * pin should provide pulses even when the LCD is blanked, otherwise
 * a pen touch needed to unblank the LCD will never be read.
 */
#include <linux/config.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/sched.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/string.h>
#include <linux/input.h>
#include <linux/device.h>
#include <linux/suspend.h>
#include <linux/slab.h>
#include <linux/kthread.h>

#include <asm/dma.h>
#include <asm/semaphore.h>

#include "ucb1x00.h"


struct ucb1x00_ts {
	struct input_dev	idev;
	struct ucb1x00		*ucb;

	wait_queue_head_t	irq_wait;
	struct task_struct	*rtask;
	u16			x_res;
	u16			y_res;

	unsigned int		restart:1;
	unsigned int		adcsync:1;
};

static int adcsync;

static inline void ucb1x00_ts_evt_add(struct ucb1x00_ts *ts, u16 pressure, u16 x, u16 y)
{
	input_report_abs(&ts->idev, ABS_X, x);
	input_report_abs(&ts->idev, ABS_Y, y);
	input_report_abs(&ts->idev, ABS_PRESSURE, pressure);
	input_sync(&ts->idev);
}

static inline void ucb1x00_ts_event_release(struct ucb1x00_ts *ts)
{
	input_report_abs(&ts->idev, ABS_PRESSURE, 0);
	input_sync(&ts->idev);
}

/*
 * Switch to interrupt mode.
 */
static inline void ucb1x00_ts_mode_int(struct ucb1x00_ts *ts)
{
	ucb1x00_reg_write(ts->ucb, 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 inline unsigned int ucb1x00_ts_read_pressure(struct ucb1x00_ts *ts)
{
	ucb1x00_reg_write(ts->ucb, 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);

	return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPY, ts->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 inline unsigned int ucb1x00_ts_read_xpos(struct ucb1x00_ts *ts)
{
	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
			UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
			UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
			UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
			UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
			UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
			UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);

	udelay(55);

	return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPY, ts->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 inline unsigned int ucb1x00_ts_read_ypos(struct ucb1x00_ts *ts)
{
	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
			UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
			UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
			UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
			UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
			UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
			UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);

	udelay(55);

	return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPX, ts->adcsync);
}

/*
 * Switch to X plate resistance mode.  Set MX to ground, PX to
 * supply.  Measure current.
 */
static inline unsigned int ucb1x00_ts_read_xres(struct ucb1x00_ts *ts)
{
	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
			UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
			UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
	return ucb1x00_adc_read(ts->ucb, 0, ts->adcsync);
}

/*
 * Switch to Y plate resistance mode.  Set MY to ground, PY to
 * supply.  Measure current.
 */
static inline unsigned int ucb1x00_ts_read_yres(struct ucb1x00_ts *ts)
{
	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
			UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
			UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
	return ucb1x00_adc_read(ts->ucb, 0, ts->adcsync);
}

/*
 * This is a RT kernel thread that handles the ADC accesses
 * (mainly so we can use semaphores in the UCB1200 core code
 * to serialise accesses to the ADC).
 */
static int ucb1x00_thread(void *_ts)
{
	struct ucb1x00_ts *ts = _ts;
	struct task_struct *tsk = current;
	DECLARE_WAITQUEUE(wait, tsk);
	int valid;

	/*
	 * We could run as a real-time thread.  However, thus far
	 * this doesn't seem to be necessary.
	 */
//	tsk->policy = SCHED_FIFO;
//	tsk->rt_priority = 1;

	valid = 0;

	add_wait_queue(&ts->irq_wait, &wait);
	while (!kthread_should_stop()) {
		unsigned int x, y, p, val;
		signed long timeout;

		ts->restart = 0;

		ucb1x00_adc_enable(ts->ucb);

		x = ucb1x00_ts_read_xpos(ts);
		y = ucb1x00_ts_read_ypos(ts);
		p = ucb1x00_ts_read_pressure(ts);

		/*
		 * Switch back to interrupt mode.
		 */
		ucb1x00_ts_mode_int(ts);
		ucb1x00_adc_disable(ts->ucb);

		msleep(10);

		ucb1x00_enable(ts->ucb);
		val = ucb1x00_reg_read(ts->ucb, UCB_TS_CR);

		if (val & (UCB_TS_CR_TSPX_LOW | UCB_TS_CR_TSMX_LOW)) {
			set_task_state(tsk, TASK_INTERRUPTIBLE);

			ucb1x00_enable_irq(ts->ucb, UCB_IRQ_TSPX, UCB_FALLING);
			ucb1x00_disable(ts->ucb);

			/*
			 * If we spat out a valid sample set last time,
			 * spit out a "pen off" sample here.
			 */
			if (valid) {
				ucb1x00_ts_event_release(ts);
				valid = 0;
			}

			timeout = MAX_SCHEDULE_TIMEOUT;
		} else {
			ucb1x00_disable(ts->ucb);

			/*
			 * Filtering is policy.  Policy belongs in user
			 * space.  We therefore leave it to user space
			 * to do any filtering they please.
			 */
			if (!ts->restart) {
				ucb1x00_ts_evt_add(ts, p, x, y);
				valid = 1;
			}

			set_task_state(tsk, TASK_INTERRUPTIBLE);
			timeout = HZ / 100;
		}

		try_to_freeze();

		schedule_timeout(timeout);
	}

	remove_wait_queue(&ts->irq_wait, &wait);

	ts->rtask = NULL;
	return 0;
}

/*
 * We only detect touch screen _touches_ with this interrupt
 * handler, and even then we just schedule our task.
 */
static void ucb1x00_ts_irq(int idx, void *id)
{
	struct ucb1x00_ts *ts = id;
	ucb1x00_disable_irq(ts->ucb, UCB_IRQ_TSPX, UCB_FALLING);
	wake_up(&ts->irq_wait);
}

static int ucb1x00_ts_open(struct input_dev *idev)
{
	struct ucb1x00_ts *ts = (struct ucb1x00_ts *)idev;
	int ret = 0;

	BUG_ON(ts->rtask);

	init_waitqueue_head(&ts->irq_wait);
	ret = ucb1x00_hook_irq(ts->ucb, UCB_IRQ_TSPX, ucb1x00_ts_irq, ts);
	if (ret < 0)
		goto out;

	/*
	 * If we do this at all, we should allow the user to
	 * measure and read the X and Y resistance at any time.
	 */
	ucb1x00_adc_enable(ts->ucb);
	ts->x_res = ucb1x00_ts_read_xres(ts);
	ts->y_res = ucb1x00_ts_read_yres(ts);
	ucb1x00_adc_disable(ts->ucb);

	ts->rtask = kthread_run(ucb1x00_thread, ts, "ktsd");
	if (!IS_ERR(ts->rtask)) {
		ret = 0;
	} else {
		ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts);
		ts->rtask = NULL;
		ret = -EFAULT;
	}

 out:
	return ret;
}

/*
 * Release touchscreen resources.  Disable IRQs.
 */
static void ucb1x00_ts_close(struct input_dev *idev)
{
	struct ucb1x00_ts *ts = (struct ucb1x00_ts *)idev;

	if (ts->rtask)
		kthread_stop(ts->rtask);

	ucb1x00_enable(ts->ucb);
	ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts);
	ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 0);
	ucb1x00_disable(ts->ucb);
}

#ifdef CONFIG_PM
static int ucb1x00_ts_resume(struct ucb1x00_dev *dev)
{
	struct ucb1x00_ts *ts = dev->priv;

	if (ts->rtask != NULL) {
		/*
		 * Restart the TS thread to ensure the
		 * TS interrupt mode is set up again
		 * after sleep.
		 */
		ts->restart = 1;
		wake_up(&ts->irq_wait);
	}
	return 0;
}
#else
#define ucb1x00_ts_resume NULL
#endif


/*
 * Initialisation.
 */
static int ucb1x00_ts_add(struct ucb1x00_dev *dev)
{
	struct ucb1x00_ts *ts;

	ts = kmalloc(sizeof(struct ucb1x00_ts), GFP_KERNEL);
	if (!ts)
		return -ENOMEM;

	memset(ts, 0, sizeof(struct ucb1x00_ts));

	ts->ucb = dev->ucb;
	ts->adcsync = adcsync ? UCB_SYNC : UCB_NOSYNC;

	ts->idev.name       = "Touchscreen panel";
	ts->idev.id.product = ts->ucb->id;
	ts->idev.open       = ucb1x00_ts_open;
	ts->idev.close      = ucb1x00_ts_close;

	__set_bit(EV_ABS, ts->idev.evbit);
	__set_bit(ABS_X, ts->idev.absbit);
	__set_bit(ABS_Y, ts->idev.absbit);
	__set_bit(ABS_PRESSURE, ts->idev.absbit);

	input_register_device(&ts->idev);

	dev->priv = ts;

	return 0;
}

static void ucb1x00_ts_remove(struct ucb1x00_dev *dev)
{
	struct ucb1x00_ts *ts = dev->priv;
	input_unregister_device(&ts->idev);
	kfree(ts);
}

static struct ucb1x00_driver ucb1x00_ts_driver = {
	.add		= ucb1x00_ts_add,
	.remove		= ucb1x00_ts_remove,
	.resume		= ucb1x00_ts_resume,
};

static int __init ucb1x00_ts_init(void)
{
	return ucb1x00_register_driver(&ucb1x00_ts_driver);
}

static void __exit ucb1x00_ts_exit(void)
{
	ucb1x00_unregister_driver(&ucb1x00_ts_driver);
}

module_param(adcsync, int, 0444);
module_init(ucb1x00_ts_init);
module_exit(ucb1x00_ts_exit);

MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
MODULE_DESCRIPTION("UCB1x00 touchscreen driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
acb45439	1	/*
5437775e	2	* Touchscreen driver for UCB1x00-based touchscreens
acb45439 RK	3	*
acb45439 RK	4	* Copyright (C) 2001 Russell King, All Rights Reserved.
5437775e	5	* Copyright (C) 2005 Pavel Machek
acb45439 RK	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2 as
	9	* published by the Free Software Foundation.
	10	*
	11	* 21-Jan-2002 <jco@ict.es> :
	12	*
	13	* Added support for synchronous A/D mode. This mode is useful to
	14	* avoid noise induced in the touchpanel by the LCD, provided that
	15	* the UCB1x00 has a valid LCD sync signal routed to its ADCSYNC pin.
	16	* It is important to note that the signal connected to the ADCSYNC
	17	* pin should provide pulses even when the LCD is blanked, otherwise
	18	* a pen touch needed to unblank the LCD will never be read.
	19	*/
	20	#include <linux/config.h>
	21	#include <linux/module.h>
	22	#include <linux/moduleparam.h>
	23	#include <linux/init.h>
	24	#include <linux/smp.h>
	25	#include <linux/smp_lock.h>
	26	#include <linux/sched.h>
	27	#include <linux/completion.h>
	28	#include <linux/delay.h>
	29	#include <linux/string.h>
	30	#include <linux/input.h>
	31	#include <linux/device.h>
	32	#include <linux/suspend.h>
	33	#include <linux/slab.h>
5437775e	34	#include <linux/kthread.h>
acb45439 RK	35
	36	#include <asm/dma.h>
	37	#include <asm/semaphore.h>
	38
	39	#include "ucb1x00.h"
	40
	41
	42	struct ucb1x00_ts {
	43	struct input_dev idev;
	44	struct ucb1x00 *ucb;
	45
	46	wait_queue_head_t irq_wait;
acb45439	47	struct task_struct *rtask;
acb45439 RK	48	u16 x_res;
	49	u16 y_res;
	50
6b9ea421 RK	51	unsigned int restart:1;
6b9ea421 RK	52	unsigned int adcsync:1;
acb45439 RK	53	};
	54
	55	static int adcsync;
	56
	57	static inline void ucb1x00_ts_evt_add(struct ucb1x00_ts *ts, u16 pressure, u16 x, u16 y)
	58	{
	59	input_report_abs(&ts->idev, ABS_X, x);
	60	input_report_abs(&ts->idev, ABS_Y, y);
	61	input_report_abs(&ts->idev, ABS_PRESSURE, pressure);
	62	input_sync(&ts->idev);
	63	}
	64
	65	static inline void ucb1x00_ts_event_release(struct ucb1x00_ts *ts)
	66	{
	67	input_report_abs(&ts->idev, ABS_PRESSURE, 0);
	68	input_sync(&ts->idev);
	69	}
	70
	71	/*
	72	* Switch to interrupt mode.
	73	*/
	74	static inline void ucb1x00_ts_mode_int(struct ucb1x00_ts *ts)
	75	{
	76	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	77	UCB_TS_CR_TSMX_POW \| UCB_TS_CR_TSPX_POW \|
	78	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_GND \|
	79	UCB_TS_CR_MODE_INT);
	80	}
	81
	82	/*
	83	* Switch to pressure mode, and read pressure. We don't need to wait
	84	* here, since both plates are being driven.
	85	*/
	86	static inline unsigned int ucb1x00_ts_read_pressure(struct ucb1x00_ts *ts)
	87	{
	88	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	89	UCB_TS_CR_TSMX_POW \| UCB_TS_CR_TSPX_POW \|
	90	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_GND \|
	91	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
	92
	93	return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPY, ts->adcsync);
	94	}
	95
	96	/*
	97	* Switch to X position mode and measure Y plate. We switch the plate
	98	* configuration in pressure mode, then switch to position mode. This
	99	* gives a faster response time. Even so, we need to wait about 55us
	100	* for things to stabilise.
	101	*/
	102	static inline unsigned int ucb1x00_ts_read_xpos(struct ucb1x00_ts *ts)
	103	{
	104	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	105	UCB_TS_CR_TSMX_GND \| UCB_TS_CR_TSPX_POW \|
	106	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
	107	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	108	UCB_TS_CR_TSMX_GND \| UCB_TS_CR_TSPX_POW \|
	109	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
	110	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	111	UCB_TS_CR_TSMX_GND \| UCB_TS_CR_TSPX_POW \|
	112	UCB_TS_CR_MODE_POS \| UCB_TS_CR_BIAS_ENA);
	113
	114	udelay(55);
	115
	116	return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPY, ts->adcsync);
117	}
118
119	/*
120	* Switch to Y position mode and measure X plate. We switch the plate
121	* configuration in pressure mode, then switch to position mode. This
122	* gives a faster response time. Even so, we need to wait about 55us
123	* for things to stabilise.
124	*/
125	static inline unsigned int ucb1x00_ts_read_ypos(struct ucb1x00_ts *ts)
126	{
127	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
128	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_POW \|
129	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
130	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
131	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_POW \|
132	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
133	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
134	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_POW \|
135	UCB_TS_CR_MODE_POS \| UCB_TS_CR_BIAS_ENA);
136
137	udelay(55);
138
139	return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPX, ts->adcsync);
140	}
141
142	/*
143	* Switch to X plate resistance mode. Set MX to ground, PX to
144	* supply. Measure current.
145	*/
146	static inline unsigned int ucb1x00_ts_read_xres(struct ucb1x00_ts *ts)
147	{
148	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
149	UCB_TS_CR_TSMX_GND \| UCB_TS_CR_TSPX_POW \|
150	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
151	return ucb1x00_adc_read(ts->ucb, 0, ts->adcsync);
152	}
153
154	/*
155	* Switch to Y plate resistance mode. Set MY to ground, PY to
156	* supply. Measure current.
157	*/
158	static inline unsigned int ucb1x00_ts_read_yres(struct ucb1x00_ts *ts)
159	{
160	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
161	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_POW \|
162	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
163	return ucb1x00_adc_read(ts->ucb, 0, ts->adcsync);
164	}
165
166	/*
167	* This is a RT kernel thread that handles the ADC accesses
168	* (mainly so we can use semaphores in the UCB1200 core code
169	* to serialise accesses to the ADC).
170	*/
171	static int ucb1x00_thread(void *_ts)
172	{
173	struct ucb1x00_ts *ts = _ts;
174	struct task_struct *tsk = current;
175	DECLARE_WAITQUEUE(wait, tsk);
176	int valid;
177
acb45439 RK	178	/*
	179	* We could run as a real-time thread. However, thus far
	180	* this doesn't seem to be necessary.
	181	*/
	182	// tsk->policy = SCHED_FIFO;
	183	// tsk->rt_priority = 1;
	184
acb45439 RK	185	valid = 0;
	186
	187	add_wait_queue(&ts->irq_wait, &wait);
5437775e	188	while (!kthread_should_stop()) {
acb45439 RK	189	unsigned int x, y, p, val;
	190	signed long timeout;
	191
	192	ts->restart = 0;
	193
	194	ucb1x00_adc_enable(ts->ucb);
	195
	196	x = ucb1x00_ts_read_xpos(ts);
	197	y = ucb1x00_ts_read_ypos(ts);
	198	p = ucb1x00_ts_read_pressure(ts);
	199
	200	/*
	201	* Switch back to interrupt mode.
	202	*/
	203	ucb1x00_ts_mode_int(ts);
	204	ucb1x00_adc_disable(ts->ucb);
	205
5437775e	206	msleep(10);
acb45439 RK	207
	208	ucb1x00_enable(ts->ucb);
	209	val = ucb1x00_reg_read(ts->ucb, UCB_TS_CR);
	210
	211	if (val & (UCB_TS_CR_TSPX_LOW \| UCB_TS_CR_TSMX_LOW)) {
	212	set_task_state(tsk, TASK_INTERRUPTIBLE);
	213
	214	ucb1x00_enable_irq(ts->ucb, UCB_IRQ_TSPX, UCB_FALLING);
	215	ucb1x00_disable(ts->ucb);
	216
	217	/*
	218	* If we spat out a valid sample set last time,
	219	* spit out a "pen off" sample here.
	220	*/
	221	if (valid) {
	222	ucb1x00_ts_event_release(ts);
	223	valid = 0;
	224	}
	225
	226	timeout = MAX_SCHEDULE_TIMEOUT;
	227	} else {
	228	ucb1x00_disable(ts->ucb);
	229
	230	/*
	231	* Filtering is policy. Policy belongs in user
	232	* space. We therefore leave it to user space
	233	* to do any filtering they please.
	234	*/
	235	if (!ts->restart) {
	236	ucb1x00_ts_evt_add(ts, p, x, y);
	237	valid = 1;
	238	}
	239
	240	set_task_state(tsk, TASK_INTERRUPTIBLE);
	241	timeout = HZ / 100;
	242	}
	243
	244	try_to_freeze();
	245
	246	schedule_timeout(timeout);
acb45439 RK	247	}
	248
	249	remove_wait_queue(&ts->irq_wait, &wait);
	250
	251	ts->rtask = NULL;
5437775e	252	return 0;
acb45439 RK	253	}
	254
	255	/*
	256	* We only detect touch screen _touches_ with this interrupt
	257	* handler, and even then we just schedule our task.
	258	*/
	259	static void ucb1x00_ts_irq(int idx, void *id)
	260	{
	261	struct ucb1x00_ts *ts = id;
	262	ucb1x00_disable_irq(ts->ucb, UCB_IRQ_TSPX, UCB_FALLING);
	263	wake_up(&ts->irq_wait);
	264	}
	265
	266	static int ucb1x00_ts_open(struct input_dev *idev)
	267	{
	268	struct ucb1x00_ts ts = (struct ucb1x00_ts )idev;
	269	int ret = 0;
	270
5437775e	271	BUG_ON(ts->rtask);
acb45439 RK	272
	273	init_waitqueue_head(&ts->irq_wait);
	274	ret = ucb1x00_hook_irq(ts->ucb, UCB_IRQ_TSPX, ucb1x00_ts_irq, ts);
	275	if (ret < 0)
	276	goto out;
	277
	278	/*
	279	* If we do this at all, we should allow the user to
	280	* measure and read the X and Y resistance at any time.
	281	*/
	282	ucb1x00_adc_enable(ts->ucb);
	283	ts->x_res = ucb1x00_ts_read_xres(ts);
	284	ts->y_res = ucb1x00_ts_read_yres(ts);
	285	ucb1x00_adc_disable(ts->ucb);
	286
5437775e PM	287	ts->rtask = kthread_run(ucb1x00_thread, ts, "ktsd");
5437775e PM	288	if (!IS_ERR(ts->rtask)) {
acb45439 RK	289	ret = 0;
	290	} else {
	291	ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts);
5437775e PM	292	ts->rtask = NULL;
5437775e PM	293	ret = -EFAULT;
acb45439 RK	294	}
	295
	296	out:
acb45439 RK	297	return ret;
	298	}
	299
	300	/*
	301	* Release touchscreen resources. Disable IRQs.
	302	*/
	303	static void ucb1x00_ts_close(struct input_dev *idev)
	304	{
	305	struct ucb1x00_ts ts = (struct ucb1x00_ts )idev;
	306
5437775e PM	307	if (ts->rtask)
5437775e PM	308	kthread_stop(ts->rtask);
acb45439	309
5437775e PM	310	ucb1x00_enable(ts->ucb);
	311	ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts);
	312	ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 0);
	313	ucb1x00_disable(ts->ucb);
acb45439 RK	314	}
	315
	316	#ifdef CONFIG_PM
	317	static int ucb1x00_ts_resume(struct ucb1x00_dev *dev)
	318	{
	319	struct ucb1x00_ts *ts = dev->priv;
	320
	321	if (ts->rtask != NULL) {
	322	/*
	323	* Restart the TS thread to ensure the
	324	* TS interrupt mode is set up again
	325	* after sleep.
	326	*/
	327	ts->restart = 1;
	328	wake_up(&ts->irq_wait);
	329	}
	330	return 0;
	331	}
	332	#else
	333	#define ucb1x00_ts_resume NULL
	334	#endif
	335
	336
	337	/*
	338	* Initialisation.
	339	*/
	340	static int ucb1x00_ts_add(struct ucb1x00_dev *dev)
	341	{
	342	struct ucb1x00_ts *ts;
	343
	344	ts = kmalloc(sizeof(struct ucb1x00_ts), GFP_KERNEL);
	345	if (!ts)
	346	return -ENOMEM;
	347
	348	memset(ts, 0, sizeof(struct ucb1x00_ts));
	349
	350	ts->ucb = dev->ucb;
	351	ts->adcsync = adcsync ? UCB_SYNC : UCB_NOSYNC;
acb45439 RK	352
	353	ts->idev.name = "Touchscreen panel";
	354	ts->idev.id.product = ts->ucb->id;
	355	ts->idev.open = ucb1x00_ts_open;
	356	ts->idev.close = ucb1x00_ts_close;
	357
	358	__set_bit(EV_ABS, ts->idev.evbit);
	359	__set_bit(ABS_X, ts->idev.absbit);
	360	__set_bit(ABS_Y, ts->idev.absbit);
	361	__set_bit(ABS_PRESSURE, ts->idev.absbit);
	362
	363	input_register_device(&ts->idev);
	364
	365	dev->priv = ts;
	366
	367	return 0;
	368	}
	369
	370	static void ucb1x00_ts_remove(struct ucb1x00_dev *dev)
	371	{
	372	struct ucb1x00_ts *ts = dev->priv;
	373	input_unregister_device(&ts->idev);
	374	kfree(ts);
	375	}
	376
	377	static struct ucb1x00_driver ucb1x00_ts_driver = {
	378	.add = ucb1x00_ts_add,
	379	.remove = ucb1x00_ts_remove,
	380	.resume = ucb1x00_ts_resume,
	381	};
	382
	383	static int __init ucb1x00_ts_init(void)
	384	{
	385	return ucb1x00_register_driver(&ucb1x00_ts_driver);
	386	}
	387
	388	static void __exit ucb1x00_ts_exit(void)
	389	{
	390	ucb1x00_unregister_driver(&ucb1x00_ts_driver);
	391	}
	392
	393	module_param(adcsync, int, 0444);
	394	module_init(ucb1x00_ts_init);
	395	module_exit(ucb1x00_ts_exit);
	396
	397	MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
	398	MODULE_DESCRIPTION("UCB1x00 touchscreen driver");
	399	MODULE_LICENSE("GPL");