[deliverable/linux.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 <asm/arch/collie.h>
#include <asm/mach-types.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)
{
	struct input_dev *idev = ts->idev;
	input_report_abs(idev, ABS_X, x);
	input_report_abs(idev, ABS_Y, y);
	input_report_abs(idev, ABS_PRESSURE, pressure);
	input_sync(idev);
}

static inline void ucb1x00_ts_event_release(struct ucb1x00_ts *ts)
{
	struct input_dev *idev = ts->idev;
	input_report_abs(idev, ABS_PRESSURE, 0);
	input_sync(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)
{
	if (machine_is_collie()) {
		ucb1x00_io_write(ts->ucb, COLLIE_TC35143_GPIO_TBL_CHK, 0);
		ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
				  UCB_TS_CR_TSPX_POW | UCB_TS_CR_TSMX_POW |
				  UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);

		udelay(55);

		return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_AD2, ts->adcsync);
	} else {
		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)
{
	if (machine_is_collie())
		ucb1x00_io_write(ts->ucb, 0, COLLIE_TC35143_GPIO_TBL_CHK);
	else {
		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)
{
	if (machine_is_collie())
		ucb1x00_io_write(ts->ucb, 0, COLLIE_TC35143_GPIO_TBL_CHK);
	else {
		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);
}

static inline int ucb1x00_ts_pen_down(struct ucb1x00_ts *ts)
{
	unsigned int val = ucb1x00_reg_read(ts->ucb, UCB_TS_CR);
	if (machine_is_collie())
		return (!(val & (UCB_TS_CR_TSPX_LOW)));
	else
		return (val & (UCB_TS_CR_TSPX_LOW | UCB_TS_CR_TSMX_LOW));
}

/*
 * 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;
		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);


		if (ucb1x00_ts_pen_down(ts)) {
			set_task_state(tsk, TASK_INTERRUPTIBLE);

			ucb1x00_enable_irq(ts->ucb, UCB_IRQ_TSPX, machine_is_collie() ? UCB_RISING : 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 = idev->private;
	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 = idev->private;

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

	ts->idev = input_allocate_device();
	if (!ts->idev) {
		kfree(ts);
		return -ENOMEM;
	}

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

	ts->idev->private = ts;
	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>
17532989 PM	38	#include <asm/arch/collie.h>
17532989 PM	39	#include <asm/mach-types.h>
acb45439 RK	40
	41	#include "ucb1x00.h"
	42
	43
	44	struct ucb1x00_ts {
bd622663	45	struct input_dev *idev;
acb45439 RK	46	struct ucb1x00 *ucb;
	47
	48	wait_queue_head_t irq_wait;
acb45439	49	struct task_struct *rtask;
acb45439 RK	50	u16 x_res;
	51	u16 y_res;
	52
6b9ea421 RK	53	unsigned int restart:1;
6b9ea421 RK	54	unsigned int adcsync:1;
acb45439 RK	55	};
	56
	57	static int adcsync;
	58
	59	static inline void ucb1x00_ts_evt_add(struct ucb1x00_ts *ts, u16 pressure, u16 x, u16 y)
	60	{
1393c3ed NP	61	struct input_dev *idev = ts->idev;
	62	input_report_abs(idev, ABS_X, x);
	63	input_report_abs(idev, ABS_Y, y);
	64	input_report_abs(idev, ABS_PRESSURE, pressure);
	65	input_sync(idev);
acb45439 RK	66	}
	67
	68	static inline void ucb1x00_ts_event_release(struct ucb1x00_ts *ts)
	69	{
1393c3ed NP	70	struct input_dev *idev = ts->idev;
	71	input_report_abs(idev, ABS_PRESSURE, 0);
	72	input_sync(idev);
acb45439 RK	73	}
	74
	75	/*
	76	* Switch to interrupt mode.
	77	*/
	78	static inline void ucb1x00_ts_mode_int(struct ucb1x00_ts *ts)
	79	{
	80	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	81	UCB_TS_CR_TSMX_POW \| UCB_TS_CR_TSPX_POW \|
	82	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_GND \|
	83	UCB_TS_CR_MODE_INT);
	84	}
	85
	86	/*
	87	* Switch to pressure mode, and read pressure. We don't need to wait
	88	* here, since both plates are being driven.
	89	*/
	90	static inline unsigned int ucb1x00_ts_read_pressure(struct ucb1x00_ts *ts)
	91	{
17532989 PM	92	if (machine_is_collie()) {
	93	ucb1x00_io_write(ts->ucb, COLLIE_TC35143_GPIO_TBL_CHK, 0);
	94	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	95	UCB_TS_CR_TSPX_POW \| UCB_TS_CR_TSMX_POW \|
	96	UCB_TS_CR_MODE_POS \| UCB_TS_CR_BIAS_ENA);
	97
	98	udelay(55);
	99
	100	return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_AD2, ts->adcsync);
	101	} else {
	102	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	103	UCB_TS_CR_TSMX_POW \| UCB_TS_CR_TSPX_POW \|
	104	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_GND \|
	105	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
	106
	107	return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPY, ts->adcsync);
	108	}
acb45439 RK	109	}
	110
	111	/*
	112	* Switch to X position mode and measure Y plate. We switch the plate
	113	* configuration in pressure mode, then switch to position mode. This
	114	* gives a faster response time. Even so, we need to wait about 55us
	115	* for things to stabilise.
	116	*/
	117	static inline unsigned int ucb1x00_ts_read_xpos(struct ucb1x00_ts *ts)
	118	{
17532989 PM	119	if (machine_is_collie())
	120	ucb1x00_io_write(ts->ucb, 0, COLLIE_TC35143_GPIO_TBL_CHK);
	121	else {
	122	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	123	UCB_TS_CR_TSMX_GND \| UCB_TS_CR_TSPX_POW \|
	124	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
	125	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	126	UCB_TS_CR_TSMX_GND \| UCB_TS_CR_TSPX_POW \|
	127	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
	128	}
acb45439 RK	129	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	130	UCB_TS_CR_TSMX_GND \| UCB_TS_CR_TSPX_POW \|
	131	UCB_TS_CR_MODE_POS \| UCB_TS_CR_BIAS_ENA);
	132
	133	udelay(55);
	134
	135	return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPY, ts->adcsync);
	136	}
	137
	138	/*
	139	* Switch to Y position mode and measure X plate. We switch the plate
	140	* configuration in pressure mode, then switch to position mode. This
	141	* gives a faster response time. Even so, we need to wait about 55us
	142	* for things to stabilise.
	143	*/
	144	static inline unsigned int ucb1x00_ts_read_ypos(struct ucb1x00_ts *ts)
	145	{
17532989 PM	146	if (machine_is_collie())
	147	ucb1x00_io_write(ts->ucb, 0, COLLIE_TC35143_GPIO_TBL_CHK);
	148	else {
	149	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	150	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_POW \|
	151	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
	152	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	153	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_POW \|
	154	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
	155	}
	156
acb45439 RK	157	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	158	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_POW \|
	159	UCB_TS_CR_MODE_POS \| UCB_TS_CR_BIAS_ENA);
	160
	161	udelay(55);
	162
	163	return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPX, ts->adcsync);
	164	}
	165
	166	/*
	167	* Switch to X plate resistance mode. Set MX to ground, PX to
	168	* supply. Measure current.
	169	*/
	170	static inline unsigned int ucb1x00_ts_read_xres(struct ucb1x00_ts *ts)
	171	{
	172	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	173	UCB_TS_CR_TSMX_GND \| UCB_TS_CR_TSPX_POW \|
	174	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
	175	return ucb1x00_adc_read(ts->ucb, 0, ts->adcsync);
	176	}
	177
	178	/*
	179	* Switch to Y plate resistance mode. Set MY to ground, PY to
	180	* supply. Measure current.
	181	*/
	182	static inline unsigned int ucb1x00_ts_read_yres(struct ucb1x00_ts *ts)
	183	{
	184	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	185	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_POW \|
	186	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
	187	return ucb1x00_adc_read(ts->ucb, 0, ts->adcsync);
	188	}
	189
17532989 PM	190	static inline int ucb1x00_ts_pen_down(struct ucb1x00_ts *ts)
	191	{
	192	unsigned int val = ucb1x00_reg_read(ts->ucb, UCB_TS_CR);
	193	if (machine_is_collie())
	194	return (!(val & (UCB_TS_CR_TSPX_LOW)));
	195	else
	196	return (val & (UCB_TS_CR_TSPX_LOW \| UCB_TS_CR_TSMX_LOW));
	197	}
	198
acb45439 RK	199	/*
	200	* This is a RT kernel thread that handles the ADC accesses
	201	* (mainly so we can use semaphores in the UCB1200 core code
	202	* to serialise accesses to the ADC).
	203	*/
	204	static int ucb1x00_thread(void *_ts)
	205	{
	206	struct ucb1x00_ts *ts = _ts;
	207	struct task_struct *tsk = current;
	208	DECLARE_WAITQUEUE(wait, tsk);
	209	int valid;
	210
acb45439 RK	211	/*
	212	* We could run as a real-time thread. However, thus far
	213	* this doesn't seem to be necessary.
	214	*/
	215	// tsk->policy = SCHED_FIFO;
	216	// tsk->rt_priority = 1;
	217
acb45439 RK	218	valid = 0;
	219
	220	add_wait_queue(&ts->irq_wait, &wait);
5437775e	221	while (!kthread_should_stop()) {
17532989	222	unsigned int x, y, p;
acb45439 RK	223	signed long timeout;
	224
	225	ts->restart = 0;
	226
	227	ucb1x00_adc_enable(ts->ucb);
	228
	229	x = ucb1x00_ts_read_xpos(ts);
	230	y = ucb1x00_ts_read_ypos(ts);
	231	p = ucb1x00_ts_read_pressure(ts);
	232
	233	/*
	234	* Switch back to interrupt mode.
	235	*/
	236	ucb1x00_ts_mode_int(ts);
	237	ucb1x00_adc_disable(ts->ucb);
	238
5437775e	239	msleep(10);
acb45439 RK	240
acb45439 RK	241	ucb1x00_enable(ts->ucb);
acb45439	242
17532989 PM	243
17532989 PM	244	if (ucb1x00_ts_pen_down(ts)) {
acb45439 RK	245	set_task_state(tsk, TASK_INTERRUPTIBLE);
acb45439 RK	246
17532989	247	ucb1x00_enable_irq(ts->ucb, UCB_IRQ_TSPX, machine_is_collie() ? UCB_RISING : UCB_FALLING);
acb45439 RK	248	ucb1x00_disable(ts->ucb);
	249
	250	/*
	251	* If we spat out a valid sample set last time,
	252	* spit out a "pen off" sample here.
	253	*/
	254	if (valid) {
	255	ucb1x00_ts_event_release(ts);
	256	valid = 0;
	257	}
	258
	259	timeout = MAX_SCHEDULE_TIMEOUT;
	260	} else {
	261	ucb1x00_disable(ts->ucb);
	262
	263	/*
	264	* Filtering is policy. Policy belongs in user
	265	* space. We therefore leave it to user space
	266	* to do any filtering they please.
	267	*/
	268	if (!ts->restart) {
	269	ucb1x00_ts_evt_add(ts, p, x, y);
	270	valid = 1;
	271	}
	272
	273	set_task_state(tsk, TASK_INTERRUPTIBLE);
	274	timeout = HZ / 100;
	275	}
	276
	277	try_to_freeze();
	278
	279	schedule_timeout(timeout);
acb45439 RK	280	}
	281
	282	remove_wait_queue(&ts->irq_wait, &wait);
	283
	284	ts->rtask = NULL;
5437775e	285	return 0;
acb45439 RK	286	}
	287
	288	/*
	289	* We only detect touch screen _touches_ with this interrupt
	290	* handler, and even then we just schedule our task.
	291	*/
	292	static void ucb1x00_ts_irq(int idx, void *id)
	293	{
	294	struct ucb1x00_ts *ts = id;
	295	ucb1x00_disable_irq(ts->ucb, UCB_IRQ_TSPX, UCB_FALLING);
	296	wake_up(&ts->irq_wait);
	297	}
	298
	299	static int ucb1x00_ts_open(struct input_dev *idev)
	300	{
1393c3ed	301	struct ucb1x00_ts *ts = idev->private;
acb45439 RK	302	int ret = 0;
acb45439 RK	303
5437775e	304	BUG_ON(ts->rtask);
acb45439 RK	305
	306	init_waitqueue_head(&ts->irq_wait);
	307	ret = ucb1x00_hook_irq(ts->ucb, UCB_IRQ_TSPX, ucb1x00_ts_irq, ts);
	308	if (ret < 0)
	309	goto out;
	310
	311	/*
	312	* If we do this at all, we should allow the user to
	313	* measure and read the X and Y resistance at any time.
	314	*/
	315	ucb1x00_adc_enable(ts->ucb);
	316	ts->x_res = ucb1x00_ts_read_xres(ts);
	317	ts->y_res = ucb1x00_ts_read_yres(ts);
	318	ucb1x00_adc_disable(ts->ucb);
	319
5437775e PM	320	ts->rtask = kthread_run(ucb1x00_thread, ts, "ktsd");
5437775e PM	321	if (!IS_ERR(ts->rtask)) {
acb45439 RK	322	ret = 0;
	323	} else {
	324	ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts);
5437775e PM	325	ts->rtask = NULL;
5437775e PM	326	ret = -EFAULT;
acb45439 RK	327	}
	328
	329	out:
acb45439 RK	330	return ret;
	331	}
	332
	333	/*
	334	* Release touchscreen resources. Disable IRQs.
	335	*/
	336	static void ucb1x00_ts_close(struct input_dev *idev)
	337	{
1393c3ed	338	struct ucb1x00_ts *ts = idev->private;
acb45439	339
5437775e PM	340	if (ts->rtask)
5437775e PM	341	kthread_stop(ts->rtask);
acb45439	342
5437775e PM	343	ucb1x00_enable(ts->ucb);
	344	ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts);
	345	ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 0);
	346	ucb1x00_disable(ts->ucb);
acb45439 RK	347	}
	348
	349	#ifdef CONFIG_PM
	350	static int ucb1x00_ts_resume(struct ucb1x00_dev *dev)
	351	{
	352	struct ucb1x00_ts *ts = dev->priv;
	353
	354	if (ts->rtask != NULL) {
	355	/*
	356	* Restart the TS thread to ensure the
	357	* TS interrupt mode is set up again
	358	* after sleep.
	359	*/
	360	ts->restart = 1;
	361	wake_up(&ts->irq_wait);
	362	}
	363	return 0;
	364	}
	365	#else
	366	#define ucb1x00_ts_resume NULL
	367	#endif
	368
	369
	370	/*
	371	* Initialisation.
	372	*/
	373	static int ucb1x00_ts_add(struct ucb1x00_dev *dev)
	374	{
	375	struct ucb1x00_ts *ts;
	376
bd622663	377	ts = kzalloc(sizeof(struct ucb1x00_ts), GFP_KERNEL);
acb45439 RK	378	if (!ts)
	379	return -ENOMEM;
	380
bd622663 DT	381	ts->idev = input_allocate_device();
	382	if (!ts->idev) {
	383	kfree(ts);
	384	return -ENOMEM;
	385	}
acb45439 RK	386
	387	ts->ucb = dev->ucb;
	388	ts->adcsync = adcsync ? UCB_SYNC : UCB_NOSYNC;
acb45439	389
1393c3ed	390	ts->idev->private = ts;
bd622663 DT	391	ts->idev->name = "Touchscreen panel";
	392	ts->idev->id.product = ts->ucb->id;
	393	ts->idev->open = ucb1x00_ts_open;
	394	ts->idev->close = ucb1x00_ts_close;
acb45439	395
bd622663 DT	396	__set_bit(EV_ABS, ts->idev->evbit);
	397	__set_bit(ABS_X, ts->idev->absbit);
	398	__set_bit(ABS_Y, ts->idev->absbit);
	399	__set_bit(ABS_PRESSURE, ts->idev->absbit);
acb45439	400
bd622663	401	input_register_device(ts->idev);
acb45439 RK	402
	403	dev->priv = ts;
	404
	405	return 0;
	406	}
	407
	408	static void ucb1x00_ts_remove(struct ucb1x00_dev *dev)
	409	{
	410	struct ucb1x00_ts *ts = dev->priv;
bd622663 DT	411
bd622663 DT	412	input_unregister_device(ts->idev);
acb45439 RK	413	kfree(ts);
	414	}
	415
	416	static struct ucb1x00_driver ucb1x00_ts_driver = {
	417	.add = ucb1x00_ts_add,
	418	.remove = ucb1x00_ts_remove,
	419	.resume = ucb1x00_ts_resume,
	420	};
	421
	422	static int __init ucb1x00_ts_init(void)
	423	{
	424	return ucb1x00_register_driver(&ucb1x00_ts_driver);
	425	}
	426
	427	static void __exit ucb1x00_ts_exit(void)
	428	{
	429	ucb1x00_unregister_driver(&ucb1x00_ts_driver);
	430	}
	431
	432	module_param(adcsync, int, 0444);
	433	module_init(ucb1x00_ts_init);
	434	module_exit(ucb1x00_ts_exit);
	435
	436	MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
	437	MODULE_DESCRIPTION("UCB1x00 touchscreen driver");
	438	MODULE_LICENSE("GPL");