[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/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/smp.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/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;

	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);

			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 (!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 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 = input_get_drvdata(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 = input_get_drvdata(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);
}


/*
 * 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;

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

	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>
	23	#include <linux/smp.h>
acb45439 RK	24	#include <linux/sched.h>
	25	#include <linux/completion.h>
	26	#include <linux/delay.h>
	27	#include <linux/string.h>
	28	#include <linux/input.h>
	29	#include <linux/device.h>
7dfb7103	30	#include <linux/freezer.h>
acb45439	31	#include <linux/slab.h>
5437775e	32	#include <linux/kthread.h>
c8602edf	33	#include <linux/mfd/ucb1x00.h>
acb45439	34
a09e64fb	35	#include <mach/collie.h>
17532989	36	#include <asm/mach-types.h>
acb45439	37
acb45439 RK	38
	39
	40	struct ucb1x00_ts {
bd622663	41	struct input_dev *idev;
acb45439 RK	42	struct ucb1x00 *ucb;
	43
	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
17532989	240	ucb1x00_enable_irq(ts->ucb, UCB_IRQ_TSPX, machine_is_collie() ? UCB_RISING : UCB_FALLING);
acb45439 RK	241	ucb1x00_disable(ts->ucb);
	242
	243	/*
	244	* If we spat out a valid sample set last time,
	245	* spit out a "pen off" sample here.
	246	*/
	247	if (valid) {
	248	ucb1x00_ts_event_release(ts);
	249	valid = 0;
	250	}
	251
	252	timeout = MAX_SCHEDULE_TIMEOUT;
	253	} else {
	254	ucb1x00_disable(ts->ucb);
	255
	256	/*
	257	* Filtering is policy. Policy belongs in user
	258	* space. We therefore leave it to user space
	259	* to do any filtering they please.
	260	*/
0af5e4c3	261	if (!ignore) {
acb45439 RK	262	ucb1x00_ts_evt_add(ts, p, x, y);
	263	valid = 1;
	264	}
	265
f7440b0e	266	set_current_state(TASK_INTERRUPTIBLE);
acb45439 RK	267	timeout = HZ / 100;
	268	}
	269
acb45439	270	schedule_timeout(timeout);
acb45439 RK	271	}
	272
	273	remove_wait_queue(&ts->irq_wait, &wait);
	274
	275	ts->rtask = NULL;
5437775e	276	return 0;
acb45439 RK	277	}
	278
	279	/*
	280	* We only detect touch screen _touches_ with this interrupt
	281	* handler, and even then we just schedule our task.
	282	*/
	283	static void ucb1x00_ts_irq(int idx, void *id)
	284	{
	285	struct ucb1x00_ts *ts = id;
08c67d2a	286
acb45439 RK	287	ucb1x00_disable_irq(ts->ucb, UCB_IRQ_TSPX, UCB_FALLING);
	288	wake_up(&ts->irq_wait);
	289	}
	290
	291	static int ucb1x00_ts_open(struct input_dev *idev)
	292	{
26be5a50	293	struct ucb1x00_ts *ts = input_get_drvdata(idev);
acb45439 RK	294	int ret = 0;
acb45439 RK	295
5437775e	296	BUG_ON(ts->rtask);
acb45439 RK	297
	298	init_waitqueue_head(&ts->irq_wait);
	299	ret = ucb1x00_hook_irq(ts->ucb, UCB_IRQ_TSPX, ucb1x00_ts_irq, ts);
	300	if (ret < 0)
	301	goto out;
	302
	303	/*
	304	* If we do this at all, we should allow the user to
	305	* measure and read the X and Y resistance at any time.
	306	*/
	307	ucb1x00_adc_enable(ts->ucb);
	308	ts->x_res = ucb1x00_ts_read_xres(ts);
	309	ts->y_res = ucb1x00_ts_read_yres(ts);
	310	ucb1x00_adc_disable(ts->ucb);
	311
5437775e PM	312	ts->rtask = kthread_run(ucb1x00_thread, ts, "ktsd");
5437775e PM	313	if (!IS_ERR(ts->rtask)) {
acb45439 RK	314	ret = 0;
	315	} else {
	316	ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts);
5437775e PM	317	ts->rtask = NULL;
5437775e PM	318	ret = -EFAULT;
acb45439 RK	319	}
	320
	321	out:
acb45439 RK	322	return ret;
	323	}
	324
	325	/*
	326	* Release touchscreen resources. Disable IRQs.
	327	*/
	328	static void ucb1x00_ts_close(struct input_dev *idev)
	329	{
26be5a50	330	struct ucb1x00_ts *ts = input_get_drvdata(idev);
acb45439	331
5437775e PM	332	if (ts->rtask)
5437775e PM	333	kthread_stop(ts->rtask);
acb45439	334
5437775e PM	335	ucb1x00_enable(ts->ucb);
	336	ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts);
	337	ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 0);
	338	ucb1x00_disable(ts->ucb);
acb45439 RK	339	}
acb45439 RK	340
acb45439 RK	341
	342	/*
	343	* Initialisation.
	344	*/
	345	static int ucb1x00_ts_add(struct ucb1x00_dev *dev)
	346	{
	347	struct ucb1x00_ts *ts;
08c67d2a DT	348	struct input_dev *idev;
08c67d2a DT	349	int err;
acb45439	350
bd622663	351	ts = kzalloc(sizeof(struct ucb1x00_ts), GFP_KERNEL);
08c67d2a DT	352	idev = input_allocate_device();
	353	if (!ts \|\| !idev) {
	354	err = -ENOMEM;
	355	goto fail;
bd622663	356	}
acb45439 RK	357
acb45439 RK	358	ts->ucb = dev->ucb;
08c67d2a	359	ts->idev = idev;
acb45439	360	ts->adcsync = adcsync ? UCB_SYNC : UCB_NOSYNC;
acb45439	361
08c67d2a	362	idev->name = "Touchscreen panel";
65f2e753	363	idev->id.product = ts->ucb->id;
08c67d2a DT	364	idev->open = ucb1x00_ts_open;
08c67d2a DT	365	idev->close = ucb1x00_ts_close;
acb45439	366
de8c8b06 JF	367	idev->evbit[0] = BIT_MASK(EV_ABS) \| BIT_MASK(EV_KEY);
de8c8b06 JF	368	idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
acb45439	369
26be5a50 DT	370	input_set_drvdata(idev, ts);
26be5a50 DT	371
9063f1f1 JF	372	ucb1x00_adc_enable(ts->ucb);
	373	ts->x_res = ucb1x00_ts_read_xres(ts);
	374	ts->y_res = ucb1x00_ts_read_yres(ts);
	375	ucb1x00_adc_disable(ts->ucb);
	376
	377	input_set_abs_params(idev, ABS_X, 0, ts->x_res, 0, 0);
	378	input_set_abs_params(idev, ABS_Y, 0, ts->y_res, 0, 0);
	379	input_set_abs_params(idev, ABS_PRESSURE, 0, 0, 0, 0);
	380
08c67d2a DT	381	err = input_register_device(idev);
	382	if (err)
	383	goto fail;
acb45439 RK	384
	385	dev->priv = ts;
	386
	387	return 0;
08c67d2a DT	388
	389	fail:
	390	input_free_device(idev);
	391	kfree(ts);
	392	return err;
acb45439 RK	393	}
	394
	395	static void ucb1x00_ts_remove(struct ucb1x00_dev *dev)
	396	{
	397	struct ucb1x00_ts *ts = dev->priv;
bd622663 DT	398
bd622663 DT	399	input_unregister_device(ts->idev);
acb45439 RK	400	kfree(ts);
	401	}
	402
	403	static struct ucb1x00_driver ucb1x00_ts_driver = {
	404	.add = ucb1x00_ts_add,
	405	.remove = ucb1x00_ts_remove,
acb45439 RK	406	};
	407
	408	static int __init ucb1x00_ts_init(void)
	409	{
	410	return ucb1x00_register_driver(&ucb1x00_ts_driver);
	411	}
	412
	413	static void __exit ucb1x00_ts_exit(void)
	414	{
	415	ucb1x00_unregister_driver(&ucb1x00_ts_driver);
	416	}
	417
	418	module_param(adcsync, int, 0444);
	419	module_init(ucb1x00_ts_init);
	420	module_exit(ucb1x00_ts_exit);
	421
	422	MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
	423	MODULE_DESCRIPTION("UCB1x00 touchscreen driver");
	424	MODULE_LICENSE("GPL");