[mirror_ubuntu-zesty-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/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/string.h>
#include <linux/input.h>
#include <linux/device.h>
#include <linux/freezer.h>
#include <linux/slab.h>
#include <linux/kthread.h>
#include <linux/mfd/ucb1x00.h>

#include <mach/collie.h>
#include <asm/mach-types.h>


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

	spinlock_t		irq_lock;
	unsigned		irq_disabled;
	wait_queue_head_t	irq_wait;
	struct task_struct	*rtask;
	u16			x_res;
	u16			y_res;

	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_report_key(idev, BTN_TOUCH, 1);
	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_report_key(idev, BTN_TOUCH, 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;
	DECLARE_WAITQUEUE(wait, current);
	bool frozen, ignore = false;
	int valid = 0;

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

		if (frozen)
			ignore = true;

		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_current_state(TASK_INTERRUPTIBLE);

			spin_lock_irq(&ts->irq_lock);
			if (ts->irq_disabled) {
				ts->irq_disabled = 0;
				enable_irq(ts->ucb->irq_base + UCB_IRQ_TSPX);
			}
			spin_unlock_irq(&ts->irq_lock);
			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 (!ignore) {
				ucb1x00_ts_evt_add(ts, p, x, y);
				valid = 1;
			}

			set_current_state(TASK_INTERRUPTIBLE);
			timeout = HZ / 100;
		}

		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 irqreturn_t ucb1x00_ts_irq(int irq, void *id)
{
	struct ucb1x00_ts *ts = id;

	spin_lock(&ts->irq_lock);
	ts->irq_disabled = 1;
	disable_irq_nosync(ts->ucb->irq_base + UCB_IRQ_TSPX);
	spin_unlock(&ts->irq_lock);
	wake_up(&ts->irq_wait);

	return IRQ_HANDLED;
}

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

	BUG_ON(ts->rtask);

	if (machine_is_collie())
		flags = IRQF_TRIGGER_RISING;
	else
		flags = IRQF_TRIGGER_FALLING;

	ts->irq_disabled = 0;

	init_waitqueue_head(&ts->irq_wait);
	ret = request_irq(ts->ucb->irq_base + UCB_IRQ_TSPX, ucb1x00_ts_irq,
			  flags, "ucb1x00-ts", 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 {
		free_irq(ts->ucb->irq_base + 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 = input_get_drvdata(idev);

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

	ucb1x00_enable(ts->ucb);
	free_irq(ts->ucb->irq_base + UCB_IRQ_TSPX, ts);
	ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 0);
	ucb1x00_disable(ts->ucb);
}


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

	ts = kzalloc(sizeof(struct ucb1x00_ts), GFP_KERNEL);
	idev = input_allocate_device();
	if (!ts || !idev) {
		err = -ENOMEM;
		goto fail;
	}

	ts->ucb = dev->ucb;
	ts->idev = idev;
	ts->adcsync = adcsync ? UCB_SYNC : UCB_NOSYNC;
	spin_lock_init(&ts->irq_lock);

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

	idev->evbit[0]   = BIT_MASK(EV_ABS) | BIT_MASK(EV_KEY);
	idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);

	input_set_drvdata(idev, ts);

	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);

	input_set_abs_params(idev, ABS_X, 0, ts->x_res, 0, 0);
	input_set_abs_params(idev, ABS_Y, 0, ts->y_res, 0, 0);
	input_set_abs_params(idev, ABS_PRESSURE, 0, 0, 0, 0);

	err = input_register_device(idev);
	if (err)
		goto fail;

	dev->priv = ts;

	return 0;

 fail:
	input_free_device(idev);
	kfree(ts);
	return err;
}

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,
};

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	*/
acb45439 RK	20	#include <linux/module.h>
	21	#include <linux/moduleparam.h>
	22	#include <linux/init.h>
a3364409	23	#include <linux/interrupt.h>
acb45439	24	#include <linux/sched.h>
a3364409	25	#include <linux/spinlock.h>
acb45439 RK	26	#include <linux/completion.h>
	27	#include <linux/delay.h>
	28	#include <linux/string.h>
	29	#include <linux/input.h>
	30	#include <linux/device.h>
7dfb7103	31	#include <linux/freezer.h>
acb45439	32	#include <linux/slab.h>
5437775e	33	#include <linux/kthread.h>
c8602edf	34	#include <linux/mfd/ucb1x00.h>
acb45439	35
a09e64fb	36	#include <mach/collie.h>
17532989	37	#include <asm/mach-types.h>
acb45439	38
acb45439 RK	39
	40
	41	struct ucb1x00_ts {
bd622663	42	struct input_dev *idev;
acb45439 RK	43	struct ucb1x00 *ucb;
acb45439 RK	44
a3364409 RK	45	spinlock_t irq_lock;
a3364409 RK	46	unsigned irq_disabled;
acb45439	47	wait_queue_head_t irq_wait;
acb45439	48	struct task_struct *rtask;
acb45439 RK	49	u16 x_res;
	50	u16 y_res;
	51
6b9ea421	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	{
1393c3ed	59	struct input_dev *idev = ts->idev;
08c67d2a	60
1393c3ed NP	61	input_report_abs(idev, ABS_X, x);
	62	input_report_abs(idev, ABS_Y, y);
	63	input_report_abs(idev, ABS_PRESSURE, pressure);
de8c8b06	64	input_report_key(idev, BTN_TOUCH, 1);
1393c3ed	65	input_sync(idev);
acb45439 RK	66	}
	67
	68	static inline void ucb1x00_ts_event_release(struct ucb1x00_ts *ts)
	69	{
1393c3ed	70	struct input_dev *idev = ts->idev;
08c67d2a	71
1393c3ed	72	input_report_abs(idev, ABS_PRESSURE, 0);
de8c8b06	73	input_report_key(idev, BTN_TOUCH, 0);
1393c3ed	74	input_sync(idev);
acb45439 RK	75	}
	76
	77	/*
	78	* Switch to interrupt mode.
	79	*/
	80	static inline void ucb1x00_ts_mode_int(struct ucb1x00_ts *ts)
	81	{
	82	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	83	UCB_TS_CR_TSMX_POW \| UCB_TS_CR_TSPX_POW \|
	84	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_GND \|
	85	UCB_TS_CR_MODE_INT);
	86	}
	87
	88	/*
	89	* Switch to pressure mode, and read pressure. We don't need to wait
	90	* here, since both plates are being driven.
	91	*/
	92	static inline unsigned int ucb1x00_ts_read_pressure(struct ucb1x00_ts *ts)
	93	{
17532989 PM	94	if (machine_is_collie()) {
	95	ucb1x00_io_write(ts->ucb, COLLIE_TC35143_GPIO_TBL_CHK, 0);
	96	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	97	UCB_TS_CR_TSPX_POW \| UCB_TS_CR_TSMX_POW \|
	98	UCB_TS_CR_MODE_POS \| UCB_TS_CR_BIAS_ENA);
	99
	100	udelay(55);
	101
	102	return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_AD2, ts->adcsync);
	103	} else {
	104	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	105	UCB_TS_CR_TSMX_POW \| UCB_TS_CR_TSPX_POW \|
	106	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_GND \|
	107	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
	108
	109	return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPY, ts->adcsync);
	110	}
acb45439 RK	111	}
	112
	113	/*
	114	* Switch to X position mode and measure Y plate. We switch the plate
	115	* configuration in pressure mode, then switch to position mode. This
	116	* gives a faster response time. Even so, we need to wait about 55us
	117	* for things to stabilise.
	118	*/
	119	static inline unsigned int ucb1x00_ts_read_xpos(struct ucb1x00_ts *ts)
	120	{
17532989 PM	121	if (machine_is_collie())
	122	ucb1x00_io_write(ts->ucb, 0, COLLIE_TC35143_GPIO_TBL_CHK);
	123	else {
	124	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	125	UCB_TS_CR_TSMX_GND \| UCB_TS_CR_TSPX_POW \|
	126	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
	127	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	128	UCB_TS_CR_TSMX_GND \| UCB_TS_CR_TSPX_POW \|
	129	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
	130	}
acb45439 RK	131	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	132	UCB_TS_CR_TSMX_GND \| UCB_TS_CR_TSPX_POW \|
	133	UCB_TS_CR_MODE_POS \| UCB_TS_CR_BIAS_ENA);
	134
	135	udelay(55);
	136
	137	return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPY, ts->adcsync);
	138	}
	139
	140	/*
	141	* Switch to Y position mode and measure X plate. We switch the plate
	142	* configuration in pressure mode, then switch to position mode. This
	143	* gives a faster response time. Even so, we need to wait about 55us
	144	* for things to stabilise.
	145	*/
	146	static inline unsigned int ucb1x00_ts_read_ypos(struct ucb1x00_ts *ts)
	147	{
17532989 PM	148	if (machine_is_collie())
	149	ucb1x00_io_write(ts->ucb, 0, COLLIE_TC35143_GPIO_TBL_CHK);
	150	else {
	151	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	152	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_POW \|
	153	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
	154	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	155	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_POW \|
	156	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
	157	}
	158
acb45439 RK	159	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	160	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_POW \|
	161	UCB_TS_CR_MODE_POS \| UCB_TS_CR_BIAS_ENA);
	162
	163	udelay(55);
	164
	165	return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPX, ts->adcsync);
	166	}
	167
	168	/*
	169	* Switch to X plate resistance mode. Set MX to ground, PX to
	170	* supply. Measure current.
	171	*/
	172	static inline unsigned int ucb1x00_ts_read_xres(struct ucb1x00_ts *ts)
	173	{
	174	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	175	UCB_TS_CR_TSMX_GND \| UCB_TS_CR_TSPX_POW \|
	176	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
	177	return ucb1x00_adc_read(ts->ucb, 0, ts->adcsync);
	178	}
	179
	180	/*
	181	* Switch to Y plate resistance mode. Set MY to ground, PY to
	182	* supply. Measure current.
	183	*/
	184	static inline unsigned int ucb1x00_ts_read_yres(struct ucb1x00_ts *ts)
	185	{
	186	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	187	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_POW \|
	188	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
	189	return ucb1x00_adc_read(ts->ucb, 0, ts->adcsync);
	190	}
	191
17532989 PM	192	static inline int ucb1x00_ts_pen_down(struct ucb1x00_ts *ts)
	193	{
	194	unsigned int val = ucb1x00_reg_read(ts->ucb, UCB_TS_CR);
08c67d2a	195
17532989 PM	196	if (machine_is_collie())
	197	return (!(val & (UCB_TS_CR_TSPX_LOW)));
	198	else
	199	return (val & (UCB_TS_CR_TSPX_LOW \| UCB_TS_CR_TSMX_LOW));
	200	}
	201
acb45439 RK	202	/*
	203	* This is a RT kernel thread that handles the ADC accesses
	204	* (mainly so we can use semaphores in the UCB1200 core code
	205	* to serialise accesses to the ADC).
	206	*/
	207	static int ucb1x00_thread(void *_ts)
	208	{
	209	struct ucb1x00_ts *ts = _ts;
f7440b0e	210	DECLARE_WAITQUEUE(wait, current);
0af5e4c3	211	bool frozen, ignore = false;
1124d5ca	212	int valid = 0;
acb45439	213
83144186	214	set_freezable();
acb45439	215	add_wait_queue(&ts->irq_wait, &wait);
0af5e4c3	216	while (!kthread_freezable_should_stop(&frozen)) {
17532989	217	unsigned int x, y, p;
acb45439 RK	218	signed long timeout;
acb45439 RK	219
0af5e4c3 RK	220	if (frozen)
0af5e4c3 RK	221	ignore = true;
acb45439 RK	222
	223	ucb1x00_adc_enable(ts->ucb);
	224
	225	x = ucb1x00_ts_read_xpos(ts);
	226	y = ucb1x00_ts_read_ypos(ts);
	227	p = ucb1x00_ts_read_pressure(ts);
	228
	229	/*
	230	* Switch back to interrupt mode.
	231	*/
	232	ucb1x00_ts_mode_int(ts);
	233	ucb1x00_adc_disable(ts->ucb);
	234
5437775e	235	msleep(10);
acb45439 RK	236
acb45439 RK	237	ucb1x00_enable(ts->ucb);
acb45439	238
17532989 PM	239
17532989 PM	240	if (ucb1x00_ts_pen_down(ts)) {
f7440b0e	241	set_current_state(TASK_INTERRUPTIBLE);
acb45439	242
a3364409 RK	243	spin_lock_irq(&ts->irq_lock);
	244	if (ts->irq_disabled) {
	245	ts->irq_disabled = 0;
	246	enable_irq(ts->ucb->irq_base + UCB_IRQ_TSPX);
	247	}
	248	spin_unlock_irq(&ts->irq_lock);
acb45439 RK	249	ucb1x00_disable(ts->ucb);
	250
	251	/*
	252	* If we spat out a valid sample set last time,
	253	* spit out a "pen off" sample here.
	254	*/
	255	if (valid) {
	256	ucb1x00_ts_event_release(ts);
	257	valid = 0;
	258	}
	259
	260	timeout = MAX_SCHEDULE_TIMEOUT;
	261	} else {
	262	ucb1x00_disable(ts->ucb);
	263
	264	/*
	265	* Filtering is policy. Policy belongs in user
	266	* space. We therefore leave it to user space
	267	* to do any filtering they please.
	268	*/
0af5e4c3	269	if (!ignore) {
acb45439 RK	270	ucb1x00_ts_evt_add(ts, p, x, y);
	271	valid = 1;
	272	}
	273
f7440b0e	274	set_current_state(TASK_INTERRUPTIBLE);
acb45439 RK	275	timeout = HZ / 100;
	276	}
	277
acb45439	278	schedule_timeout(timeout);
acb45439 RK	279	}
	280
	281	remove_wait_queue(&ts->irq_wait, &wait);
	282
	283	ts->rtask = NULL;
5437775e	284	return 0;
acb45439 RK	285	}
	286
	287	/*
	288	* We only detect touch screen _touches_ with this interrupt
	289	* handler, and even then we just schedule our task.
	290	*/
a3364409	291	static irqreturn_t ucb1x00_ts_irq(int irq, void *id)
acb45439 RK	292	{
acb45439 RK	293	struct ucb1x00_ts *ts = id;
08c67d2a	294
a3364409 RK	295	spin_lock(&ts->irq_lock);
	296	ts->irq_disabled = 1;
	297	disable_irq_nosync(ts->ucb->irq_base + UCB_IRQ_TSPX);
	298	spin_unlock(&ts->irq_lock);
acb45439	299	wake_up(&ts->irq_wait);
a3364409 RK	300
a3364409 RK	301	return IRQ_HANDLED;
acb45439 RK	302	}
	303
	304	static int ucb1x00_ts_open(struct input_dev *idev)
	305	{
26be5a50	306	struct ucb1x00_ts *ts = input_get_drvdata(idev);
a3364409	307	unsigned long flags = 0;
acb45439 RK	308	int ret = 0;
acb45439 RK	309
5437775e	310	BUG_ON(ts->rtask);
acb45439	311
a3364409 RK	312	if (machine_is_collie())
	313	flags = IRQF_TRIGGER_RISING;
	314	else
	315	flags = IRQF_TRIGGER_FALLING;
	316
	317	ts->irq_disabled = 0;
	318
acb45439	319	init_waitqueue_head(&ts->irq_wait);
a3364409 RK	320	ret = request_irq(ts->ucb->irq_base + UCB_IRQ_TSPX, ucb1x00_ts_irq,
a3364409 RK	321	flags, "ucb1x00-ts", ts);
acb45439 RK	322	if (ret < 0)
	323	goto out;
	324
	325	/*
	326	* If we do this at all, we should allow the user to
	327	* measure and read the X and Y resistance at any time.
	328	*/
	329	ucb1x00_adc_enable(ts->ucb);
	330	ts->x_res = ucb1x00_ts_read_xres(ts);
	331	ts->y_res = ucb1x00_ts_read_yres(ts);
	332	ucb1x00_adc_disable(ts->ucb);
	333
5437775e PM	334	ts->rtask = kthread_run(ucb1x00_thread, ts, "ktsd");
5437775e PM	335	if (!IS_ERR(ts->rtask)) {
acb45439 RK	336	ret = 0;
acb45439 RK	337	} else {
a3364409	338	free_irq(ts->ucb->irq_base + UCB_IRQ_TSPX, ts);
5437775e PM	339	ts->rtask = NULL;
5437775e PM	340	ret = -EFAULT;
acb45439 RK	341	}
	342
	343	out:
acb45439 RK	344	return ret;
	345	}
	346
	347	/*
	348	* Release touchscreen resources. Disable IRQs.
	349	*/
	350	static void ucb1x00_ts_close(struct input_dev *idev)
	351	{
26be5a50	352	struct ucb1x00_ts *ts = input_get_drvdata(idev);
acb45439	353
5437775e PM	354	if (ts->rtask)
5437775e PM	355	kthread_stop(ts->rtask);
acb45439	356
5437775e	357	ucb1x00_enable(ts->ucb);
a3364409	358	free_irq(ts->ucb->irq_base + UCB_IRQ_TSPX, ts);
5437775e PM	359	ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 0);
5437775e PM	360	ucb1x00_disable(ts->ucb);
acb45439 RK	361	}
acb45439 RK	362
acb45439 RK	363
	364	/*
	365	* Initialisation.
	366	*/
	367	static int ucb1x00_ts_add(struct ucb1x00_dev *dev)
	368	{
	369	struct ucb1x00_ts *ts;
08c67d2a DT	370	struct input_dev *idev;
08c67d2a DT	371	int err;
acb45439	372
bd622663	373	ts = kzalloc(sizeof(struct ucb1x00_ts), GFP_KERNEL);
08c67d2a DT	374	idev = input_allocate_device();
	375	if (!ts \|\| !idev) {
	376	err = -ENOMEM;
	377	goto fail;
bd622663	378	}
acb45439 RK	379
acb45439 RK	380	ts->ucb = dev->ucb;
08c67d2a	381	ts->idev = idev;
acb45439	382	ts->adcsync = adcsync ? UCB_SYNC : UCB_NOSYNC;
a3364409	383	spin_lock_init(&ts->irq_lock);
acb45439	384
08c67d2a	385	idev->name = "Touchscreen panel";
65f2e753	386	idev->id.product = ts->ucb->id;
08c67d2a DT	387	idev->open = ucb1x00_ts_open;
08c67d2a DT	388	idev->close = ucb1x00_ts_close;
945f6310	389	idev->dev.parent = &ts->ucb->dev;
acb45439	390
de8c8b06 JF	391	idev->evbit[0] = BIT_MASK(EV_ABS) \| BIT_MASK(EV_KEY);
de8c8b06 JF	392	idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
acb45439	393
26be5a50 DT	394	input_set_drvdata(idev, ts);
26be5a50 DT	395
9063f1f1 JF	396	ucb1x00_adc_enable(ts->ucb);
	397	ts->x_res = ucb1x00_ts_read_xres(ts);
	398	ts->y_res = ucb1x00_ts_read_yres(ts);
	399	ucb1x00_adc_disable(ts->ucb);
	400
	401	input_set_abs_params(idev, ABS_X, 0, ts->x_res, 0, 0);
	402	input_set_abs_params(idev, ABS_Y, 0, ts->y_res, 0, 0);
	403	input_set_abs_params(idev, ABS_PRESSURE, 0, 0, 0, 0);
	404
08c67d2a DT	405	err = input_register_device(idev);
	406	if (err)
	407	goto fail;
acb45439 RK	408
	409	dev->priv = ts;
	410
	411	return 0;
08c67d2a DT	412
	413	fail:
	414	input_free_device(idev);
	415	kfree(ts);
	416	return err;
acb45439 RK	417	}
	418
	419	static void ucb1x00_ts_remove(struct ucb1x00_dev *dev)
	420	{
	421	struct ucb1x00_ts *ts = dev->priv;
bd622663 DT	422
bd622663 DT	423	input_unregister_device(ts->idev);
acb45439 RK	424	kfree(ts);
	425	}
	426
	427	static struct ucb1x00_driver ucb1x00_ts_driver = {
	428	.add = ucb1x00_ts_add,
	429	.remove = ucb1x00_ts_remove,
acb45439 RK	430	};
	431
	432	static int __init ucb1x00_ts_init(void)
	433	{
	434	return ucb1x00_register_driver(&ucb1x00_ts_driver);
	435	}
	436
	437	static void __exit ucb1x00_ts_exit(void)
	438	{
	439	ucb1x00_unregister_driver(&ucb1x00_ts_driver);
	440	}
	441
	442	module_param(adcsync, int, 0444);
	443	module_init(ucb1x00_ts_init);
	444	module_exit(ucb1x00_ts_exit);
	445
	446	MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
	447	MODULE_DESCRIPTION("UCB1x00 touchscreen driver");
	448	MODULE_LICENSE("GPL");