[linux-2.6-block.git] / drivers / mfd / ucb1x00-ts.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 *  Touchscreen driver for UCB1x00-based touchscreens
 *
 *  Copyright (C) 2001 Russell King, All Rights Reserved.
 *  Copyright (C) 2005 Pavel Machek
 *
 * 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
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
acb45439	2	/*
5437775e	3	* Touchscreen driver for UCB1x00-based touchscreens
acb45439 RK	4	*
acb45439 RK	5	* Copyright (C) 2001 Russell King, All Rights Reserved.
5437775e	6	* Copyright (C) 2005 Pavel Machek
acb45439	7	*
acb45439 RK	8	* 21-Jan-2002 <jco@ict.es> :
	9	*
	10	* Added support for synchronous A/D mode. This mode is useful to
	11	* avoid noise induced in the touchpanel by the LCD, provided that
	12	* the UCB1x00 has a valid LCD sync signal routed to its ADCSYNC pin.
	13	* It is important to note that the signal connected to the ADCSYNC
	14	* pin should provide pulses even when the LCD is blanked, otherwise
	15	* a pen touch needed to unblank the LCD will never be read.
	16	*/
acb45439 RK	17	#include <linux/module.h>
	18	#include <linux/moduleparam.h>
	19	#include <linux/init.h>
a3364409	20	#include <linux/interrupt.h>
acb45439	21	#include <linux/sched.h>
a3364409	22	#include <linux/spinlock.h>
acb45439 RK	23	#include <linux/completion.h>
	24	#include <linux/delay.h>
	25	#include <linux/string.h>
	26	#include <linux/input.h>
	27	#include <linux/device.h>
7dfb7103	28	#include <linux/freezer.h>
acb45439	29	#include <linux/slab.h>
5437775e	30	#include <linux/kthread.h>
c8602edf	31	#include <linux/mfd/ucb1x00.h>
acb45439	32
a09e64fb	33	#include <mach/collie.h>
17532989	34	#include <asm/mach-types.h>
acb45439	35
acb45439 RK	36
	37
	38	struct ucb1x00_ts {
bd622663	39	struct input_dev *idev;
acb45439 RK	40	struct ucb1x00 *ucb;
acb45439 RK	41
a3364409 RK	42	spinlock_t irq_lock;
a3364409 RK	43	unsigned irq_disabled;
acb45439	44	wait_queue_head_t irq_wait;
acb45439	45	struct task_struct *rtask;
acb45439 RK	46	u16 x_res;
	47	u16 y_res;
	48
6b9ea421	49	unsigned int adcsync:1;
acb45439 RK	50	};
	51
	52	static int adcsync;
	53
	54	static inline void ucb1x00_ts_evt_add(struct ucb1x00_ts *ts, u16 pressure, u16 x, u16 y)
	55	{
1393c3ed	56	struct input_dev *idev = ts->idev;
08c67d2a	57
1393c3ed NP	58	input_report_abs(idev, ABS_X, x);
	59	input_report_abs(idev, ABS_Y, y);
	60	input_report_abs(idev, ABS_PRESSURE, pressure);
de8c8b06	61	input_report_key(idev, BTN_TOUCH, 1);
1393c3ed	62	input_sync(idev);
acb45439 RK	63	}
	64
	65	static inline void ucb1x00_ts_event_release(struct ucb1x00_ts *ts)
	66	{
1393c3ed	67	struct input_dev *idev = ts->idev;
08c67d2a	68
1393c3ed	69	input_report_abs(idev, ABS_PRESSURE, 0);
de8c8b06	70	input_report_key(idev, BTN_TOUCH, 0);
1393c3ed	71	input_sync(idev);
acb45439 RK	72	}
	73
	74	/*
	75	* Switch to interrupt mode.
	76	*/
	77	static inline void ucb1x00_ts_mode_int(struct ucb1x00_ts *ts)
	78	{
	79	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	80	UCB_TS_CR_TSMX_POW \| UCB_TS_CR_TSPX_POW \|
	81	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_GND \|
	82	UCB_TS_CR_MODE_INT);
	83	}
	84
	85	/*
	86	* Switch to pressure mode, and read pressure. We don't need to wait
	87	* here, since both plates are being driven.
	88	*/
	89	static inline unsigned int ucb1x00_ts_read_pressure(struct ucb1x00_ts *ts)
	90	{
17532989 PM	91	if (machine_is_collie()) {
	92	ucb1x00_io_write(ts->ucb, COLLIE_TC35143_GPIO_TBL_CHK, 0);
	93	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	94	UCB_TS_CR_TSPX_POW \| UCB_TS_CR_TSMX_POW \|
	95	UCB_TS_CR_MODE_POS \| UCB_TS_CR_BIAS_ENA);
	96
	97	udelay(55);
	98
	99	return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_AD2, ts->adcsync);
	100	} else {
	101	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	102	UCB_TS_CR_TSMX_POW \| UCB_TS_CR_TSPX_POW \|
	103	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_GND \|
	104	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
	105
	106	return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPY, ts->adcsync);
	107	}
acb45439 RK	108	}
	109
	110	/*
	111	* Switch to X position mode and measure Y plate. We switch the plate
	112	* configuration in pressure mode, then switch to position mode. This
	113	* gives a faster response time. Even so, we need to wait about 55us
	114	* for things to stabilise.
	115	*/
	116	static inline unsigned int ucb1x00_ts_read_xpos(struct ucb1x00_ts *ts)
	117	{
17532989 PM	118	if (machine_is_collie())
	119	ucb1x00_io_write(ts->ucb, 0, COLLIE_TC35143_GPIO_TBL_CHK);
	120	else {
	121	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	122	UCB_TS_CR_TSMX_GND \| UCB_TS_CR_TSPX_POW \|
	123	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
	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	}
acb45439 RK	128	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	129	UCB_TS_CR_TSMX_GND \| UCB_TS_CR_TSPX_POW \|
	130	UCB_TS_CR_MODE_POS \| UCB_TS_CR_BIAS_ENA);
	131
	132	udelay(55);
	133
	134	return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPY, ts->adcsync);
	135	}
	136
	137	/*
	138	* Switch to Y position mode and measure X plate. We switch the plate
	139	* configuration in pressure mode, then switch to position mode. This
	140	* gives a faster response time. Even so, we need to wait about 55us
	141	* for things to stabilise.
	142	*/
	143	static inline unsigned int ucb1x00_ts_read_ypos(struct ucb1x00_ts *ts)
	144	{
17532989 PM	145	if (machine_is_collie())
	146	ucb1x00_io_write(ts->ucb, 0, COLLIE_TC35143_GPIO_TBL_CHK);
	147	else {
	148	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	149	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_POW \|
	150	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
	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	}
	155
acb45439 RK	156	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	157	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_POW \|
	158	UCB_TS_CR_MODE_POS \| UCB_TS_CR_BIAS_ENA);
	159
	160	udelay(55);
	161
	162	return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPX, ts->adcsync);
	163	}
	164
	165	/*
	166	* Switch to X plate resistance mode. Set MX to ground, PX to
	167	* supply. Measure current.
	168	*/
	169	static inline unsigned int ucb1x00_ts_read_xres(struct ucb1x00_ts *ts)
	170	{
	171	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	172	UCB_TS_CR_TSMX_GND \| UCB_TS_CR_TSPX_POW \|
	173	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
	174	return ucb1x00_adc_read(ts->ucb, 0, ts->adcsync);
	175	}
	176
	177	/*
	178	* Switch to Y plate resistance mode. Set MY to ground, PY to
	179	* supply. Measure current.
	180	*/
	181	static inline unsigned int ucb1x00_ts_read_yres(struct ucb1x00_ts *ts)
	182	{
	183	ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
	184	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_POW \|
	185	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
	186	return ucb1x00_adc_read(ts->ucb, 0, ts->adcsync);
	187	}
	188
17532989 PM	189	static inline int ucb1x00_ts_pen_down(struct ucb1x00_ts *ts)
	190	{
	191	unsigned int val = ucb1x00_reg_read(ts->ucb, UCB_TS_CR);
08c67d2a	192
17532989 PM	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;
f7440b0e	207	DECLARE_WAITQUEUE(wait, current);
0af5e4c3	208	bool frozen, ignore = false;
1124d5ca	209	int valid = 0;
acb45439	210
83144186	211	set_freezable();
acb45439	212	add_wait_queue(&ts->irq_wait, &wait);
0af5e4c3	213	while (!kthread_freezable_should_stop(&frozen)) {
17532989	214	unsigned int x, y, p;
acb45439 RK	215	signed long timeout;
acb45439 RK	216
0af5e4c3 RK	217	if (frozen)
0af5e4c3 RK	218	ignore = true;
acb45439 RK	219
	220	ucb1x00_adc_enable(ts->ucb);
	221
	222	x = ucb1x00_ts_read_xpos(ts);
	223	y = ucb1x00_ts_read_ypos(ts);
	224	p = ucb1x00_ts_read_pressure(ts);
	225
	226	/*
	227	* Switch back to interrupt mode.
	228	*/
	229	ucb1x00_ts_mode_int(ts);
	230	ucb1x00_adc_disable(ts->ucb);
	231
5437775e	232	msleep(10);
acb45439 RK	233
acb45439 RK	234	ucb1x00_enable(ts->ucb);
acb45439	235
17532989 PM	236
17532989 PM	237	if (ucb1x00_ts_pen_down(ts)) {
f7440b0e	238	set_current_state(TASK_INTERRUPTIBLE);
acb45439	239
a3364409 RK	240	spin_lock_irq(&ts->irq_lock);
	241	if (ts->irq_disabled) {
	242	ts->irq_disabled = 0;
	243	enable_irq(ts->ucb->irq_base + UCB_IRQ_TSPX);
	244	}
	245	spin_unlock_irq(&ts->irq_lock);
acb45439 RK	246	ucb1x00_disable(ts->ucb);
	247
	248	/*
	249	* If we spat out a valid sample set last time,
	250	* spit out a "pen off" sample here.
	251	*/
	252	if (valid) {
	253	ucb1x00_ts_event_release(ts);
	254	valid = 0;
	255	}
	256
	257	timeout = MAX_SCHEDULE_TIMEOUT;
	258	} else {
	259	ucb1x00_disable(ts->ucb);
	260
	261	/*
	262	* Filtering is policy. Policy belongs in user
	263	* space. We therefore leave it to user space
	264	* to do any filtering they please.
	265	*/
0af5e4c3	266	if (!ignore) {
acb45439 RK	267	ucb1x00_ts_evt_add(ts, p, x, y);
	268	valid = 1;
	269	}
	270
f7440b0e	271	set_current_state(TASK_INTERRUPTIBLE);
acb45439 RK	272	timeout = HZ / 100;
	273	}
	274
acb45439	275	schedule_timeout(timeout);
acb45439 RK	276	}
	277
	278	remove_wait_queue(&ts->irq_wait, &wait);
	279
	280	ts->rtask = NULL;
5437775e	281	return 0;
acb45439 RK	282	}
	283
	284	/*
	285	* We only detect touch screen _touches_ with this interrupt
	286	* handler, and even then we just schedule our task.
	287	*/
a3364409	288	static irqreturn_t ucb1x00_ts_irq(int irq, void *id)
acb45439 RK	289	{
acb45439 RK	290	struct ucb1x00_ts *ts = id;
08c67d2a	291
a3364409 RK	292	spin_lock(&ts->irq_lock);
	293	ts->irq_disabled = 1;
	294	disable_irq_nosync(ts->ucb->irq_base + UCB_IRQ_TSPX);
	295	spin_unlock(&ts->irq_lock);
acb45439	296	wake_up(&ts->irq_wait);
a3364409 RK	297
a3364409 RK	298	return IRQ_HANDLED;
acb45439 RK	299	}
	300
	301	static int ucb1x00_ts_open(struct input_dev *idev)
	302	{
26be5a50	303	struct ucb1x00_ts *ts = input_get_drvdata(idev);
a3364409	304	unsigned long flags = 0;
acb45439 RK	305	int ret = 0;
acb45439 RK	306
5437775e	307	BUG_ON(ts->rtask);
acb45439	308
a3364409 RK	309	if (machine_is_collie())
	310	flags = IRQF_TRIGGER_RISING;
	311	else
	312	flags = IRQF_TRIGGER_FALLING;
	313
	314	ts->irq_disabled = 0;
	315
acb45439	316	init_waitqueue_head(&ts->irq_wait);
a3364409 RK	317	ret = request_irq(ts->ucb->irq_base + UCB_IRQ_TSPX, ucb1x00_ts_irq,
a3364409 RK	318	flags, "ucb1x00-ts", ts);
acb45439 RK	319	if (ret < 0)
	320	goto out;
	321
	322	/*
	323	* If we do this at all, we should allow the user to
	324	* measure and read the X and Y resistance at any time.
	325	*/
	326	ucb1x00_adc_enable(ts->ucb);
	327	ts->x_res = ucb1x00_ts_read_xres(ts);
	328	ts->y_res = ucb1x00_ts_read_yres(ts);
	329	ucb1x00_adc_disable(ts->ucb);
	330
5437775e PM	331	ts->rtask = kthread_run(ucb1x00_thread, ts, "ktsd");
5437775e PM	332	if (!IS_ERR(ts->rtask)) {
acb45439 RK	333	ret = 0;
acb45439 RK	334	} else {
a3364409	335	free_irq(ts->ucb->irq_base + UCB_IRQ_TSPX, ts);
5437775e PM	336	ts->rtask = NULL;
5437775e PM	337	ret = -EFAULT;
acb45439 RK	338	}
	339
	340	out:
acb45439 RK	341	return ret;
	342	}
	343
	344	/*
	345	* Release touchscreen resources. Disable IRQs.
	346	*/
	347	static void ucb1x00_ts_close(struct input_dev *idev)
	348	{
26be5a50	349	struct ucb1x00_ts *ts = input_get_drvdata(idev);
acb45439	350
5437775e PM	351	if (ts->rtask)
5437775e PM	352	kthread_stop(ts->rtask);
acb45439	353
5437775e	354	ucb1x00_enable(ts->ucb);
a3364409	355	free_irq(ts->ucb->irq_base + UCB_IRQ_TSPX, ts);
5437775e PM	356	ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 0);
5437775e PM	357	ucb1x00_disable(ts->ucb);
acb45439 RK	358	}
acb45439 RK	359
acb45439 RK	360
	361	/*
	362	* Initialisation.
	363	*/
	364	static int ucb1x00_ts_add(struct ucb1x00_dev *dev)
	365	{
	366	struct ucb1x00_ts *ts;
08c67d2a DT	367	struct input_dev *idev;
08c67d2a DT	368	int err;
acb45439	369
bd622663	370	ts = kzalloc(sizeof(struct ucb1x00_ts), GFP_KERNEL);
08c67d2a DT	371	idev = input_allocate_device();
	372	if (!ts \|\| !idev) {
	373	err = -ENOMEM;
	374	goto fail;
bd622663	375	}
acb45439 RK	376
acb45439 RK	377	ts->ucb = dev->ucb;
08c67d2a	378	ts->idev = idev;
acb45439	379	ts->adcsync = adcsync ? UCB_SYNC : UCB_NOSYNC;
a3364409	380	spin_lock_init(&ts->irq_lock);
acb45439	381
08c67d2a	382	idev->name = "Touchscreen panel";
65f2e753	383	idev->id.product = ts->ucb->id;
08c67d2a DT	384	idev->open = ucb1x00_ts_open;
08c67d2a DT	385	idev->close = ucb1x00_ts_close;
945f6310	386	idev->dev.parent = &ts->ucb->dev;
acb45439	387
de8c8b06 JF	388	idev->evbit[0] = BIT_MASK(EV_ABS) \| BIT_MASK(EV_KEY);
de8c8b06 JF	389	idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
acb45439	390
26be5a50 DT	391	input_set_drvdata(idev, ts);
26be5a50 DT	392
9063f1f1 JF	393	ucb1x00_adc_enable(ts->ucb);
	394	ts->x_res = ucb1x00_ts_read_xres(ts);
	395	ts->y_res = ucb1x00_ts_read_yres(ts);
	396	ucb1x00_adc_disable(ts->ucb);
	397
	398	input_set_abs_params(idev, ABS_X, 0, ts->x_res, 0, 0);
	399	input_set_abs_params(idev, ABS_Y, 0, ts->y_res, 0, 0);
	400	input_set_abs_params(idev, ABS_PRESSURE, 0, 0, 0, 0);
	401
08c67d2a DT	402	err = input_register_device(idev);
	403	if (err)
	404	goto fail;
acb45439 RK	405
	406	dev->priv = ts;
	407
	408	return 0;
08c67d2a DT	409
	410	fail:
	411	input_free_device(idev);
	412	kfree(ts);
	413	return err;
acb45439 RK	414	}
	415
	416	static void ucb1x00_ts_remove(struct ucb1x00_dev *dev)
	417	{
	418	struct ucb1x00_ts *ts = dev->priv;
bd622663 DT	419
bd622663 DT	420	input_unregister_device(ts->idev);
acb45439 RK	421	kfree(ts);
	422	}
	423
	424	static struct ucb1x00_driver ucb1x00_ts_driver = {
	425	.add = ucb1x00_ts_add,
	426	.remove = ucb1x00_ts_remove,
acb45439 RK	427	};
	428
	429	static int __init ucb1x00_ts_init(void)
	430	{
	431	return ucb1x00_register_driver(&ucb1x00_ts_driver);
	432	}
	433
	434	static void __exit ucb1x00_ts_exit(void)
	435	{
	436	ucb1x00_unregister_driver(&ucb1x00_ts_driver);
	437	}
	438
	439	module_param(adcsync, int, 0444);
	440	module_init(ucb1x00_ts_init);
	441	module_exit(ucb1x00_ts_exit);
	442
	443	MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
	444	MODULE_DESCRIPTION("UCB1x00 touchscreen driver");
	445	MODULE_LICENSE("GPL");