1/*
2 *  Touchscreen driver for UCB1x00-based touchscreens
3 *
4 *  Copyright (C) 2001 Russell King, All Rights Reserved.
5 *  Copyright (C) 2005 Pavel Machek
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/module.h>
21#include <linux/moduleparam.h>
22#include <linux/init.h>
23#include <linux/smp.h>
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>
30#include <linux/freezer.h>
31#include <linux/slab.h>
32#include <linux/kthread.h>
33
34#include <asm/dma.h>
35#include <asm/semaphore.h>
36#include <asm/arch/collie.h>
37#include <asm/mach-types.h>
38
39#include "ucb1x00.h"
40
41
42struct ucb1x00_ts {
43	struct input_dev	*idev;
44	struct ucb1x00		*ucb;
45
46	wait_queue_head_t	irq_wait;
47	struct task_struct	*rtask;
48	u16			x_res;
49	u16			y_res;
50
51	unsigned int		restart:1;
52	unsigned int		adcsync:1;
53};
54
55static int adcsync;
56
57static inline void ucb1x00_ts_evt_add(struct ucb1x00_ts *ts, u16 pressure, u16 x, u16 y)
58{
59	struct input_dev *idev = ts->idev;
60
61	input_report_abs(idev, ABS_X, x);
62	input_report_abs(idev, ABS_Y, y);
63	input_report_abs(idev, ABS_PRESSURE, pressure);
64	input_sync(idev);
65}
66
67static inline void ucb1x00_ts_event_release(struct ucb1x00_ts *ts)
68{
69	struct input_dev *idev = ts->idev;
70
71	input_report_abs(idev, ABS_PRESSURE, 0);
72	input_sync(idev);
73}
74
75/*
76 * Switch to interrupt mode.
77 */
78static 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 */
90static inline unsigned int ucb1x00_ts_read_pressure(struct ucb1x00_ts *ts)
91{
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	}
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 */
117static inline unsigned int ucb1x00_ts_read_xpos(struct ucb1x00_ts *ts)
118{
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	}
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 */
144static inline unsigned int ucb1x00_ts_read_ypos(struct ucb1x00_ts *ts)
145{
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
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 */
170static 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 */
182static 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
190static inline int ucb1x00_ts_pen_down(struct ucb1x00_ts *ts)
191{
192	unsigned int val = ucb1x00_reg_read(ts->ucb, UCB_TS_CR);
193
194	if (machine_is_collie())
195		return (!(val & (UCB_TS_CR_TSPX_LOW)));
196	else
197		return (val & (UCB_TS_CR_TSPX_LOW | UCB_TS_CR_TSMX_LOW));
198}
199
200/*
201 * This is a RT kernel thread that handles the ADC accesses
202 * (mainly so we can use semaphores in the UCB1200 core code
203 * to serialise accesses to the ADC).
204 */
205static int ucb1x00_thread(void *_ts)
206{
207	struct ucb1x00_ts *ts = _ts;
208	struct task_struct *tsk = current;
209	DECLARE_WAITQUEUE(wait, tsk);
210	int valid = 0;
211
212	add_wait_queue(&ts->irq_wait, &wait);
213	while (!kthread_should_stop()) {
214		unsigned int x, y, p;
215		signed long timeout;
216
217		ts->restart = 0;
218
219		ucb1x00_adc_enable(ts->ucb);
220
221		x = ucb1x00_ts_read_xpos(ts);
222		y = ucb1x00_ts_read_ypos(ts);
223		p = ucb1x00_ts_read_pressure(ts);
224
225		/*
226		 * Switch back to interrupt mode.
227		 */
228		ucb1x00_ts_mode_int(ts);
229		ucb1x00_adc_disable(ts->ucb);
230
231		msleep(10);
232
233		ucb1x00_enable(ts->ucb);
234
235
236		if (ucb1x00_ts_pen_down(ts)) {
237			set_task_state(tsk, TASK_INTERRUPTIBLE);
238
239			ucb1x00_enable_irq(ts->ucb, UCB_IRQ_TSPX, machine_is_collie() ? UCB_RISING : UCB_FALLING);
240			ucb1x00_disable(ts->ucb);
241
242			/*
243			 * If we spat out a valid sample set last time,
244			 * spit out a "pen off" sample here.
245			 */
246			if (valid) {
247				ucb1x00_ts_event_release(ts);
248				valid = 0;
249			}
250
251			timeout = MAX_SCHEDULE_TIMEOUT;
252		} else {
253			ucb1x00_disable(ts->ucb);
254
255			/*
256			 * Filtering is policy.  Policy belongs in user
257			 * space.  We therefore leave it to user space
258			 * to do any filtering they please.
259			 */
260			if (!ts->restart) {
261				ucb1x00_ts_evt_add(ts, p, x, y);
262				valid = 1;
263			}
264
265			set_task_state(tsk, TASK_INTERRUPTIBLE);
266			timeout = HZ / 100;
267		}
268
269		try_to_freeze();
270
271		schedule_timeout(timeout);
272	}
273
274	remove_wait_queue(&ts->irq_wait, &wait);
275
276	ts->rtask = NULL;
277	return 0;
278}
279
280/*
281 * We only detect touch screen _touches_ with this interrupt
282 * handler, and even then we just schedule our task.
283 */
284static void ucb1x00_ts_irq(int idx, void *id)
285{
286	struct ucb1x00_ts *ts = id;
287
288	ucb1x00_disable_irq(ts->ucb, UCB_IRQ_TSPX, UCB_FALLING);
289	wake_up(&ts->irq_wait);
290}
291
292static int ucb1x00_ts_open(struct input_dev *idev)
293{
294	struct ucb1x00_ts *ts = input_get_drvdata(idev);
295	int ret = 0;
296
297	BUG_ON(ts->rtask);
298
299	init_waitqueue_head(&ts->irq_wait);
300	ret = ucb1x00_hook_irq(ts->ucb, UCB_IRQ_TSPX, ucb1x00_ts_irq, ts);
301	if (ret < 0)
302		goto out;
303
304	/*
305	 * If we do this at all, we should allow the user to
306	 * measure and read the X and Y resistance at any time.
307	 */
308	ucb1x00_adc_enable(ts->ucb);
309	ts->x_res = ucb1x00_ts_read_xres(ts);
310	ts->y_res = ucb1x00_ts_read_yres(ts);
311	ucb1x00_adc_disable(ts->ucb);
312
313	ts->rtask = kthread_run(ucb1x00_thread, ts, "ktsd");
314	if (!IS_ERR(ts->rtask)) {
315		ret = 0;
316	} else {
317		ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts);
318		ts->rtask = NULL;
319		ret = -EFAULT;
320	}
321
322 out:
323	return ret;
324}
325
326/*
327 * Release touchscreen resources.  Disable IRQs.
328 */
329static void ucb1x00_ts_close(struct input_dev *idev)
330{
331	struct ucb1x00_ts *ts = input_get_drvdata(idev);
332
333	if (ts->rtask)
334		kthread_stop(ts->rtask);
335
336	ucb1x00_enable(ts->ucb);
337	ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts);
338	ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 0);
339	ucb1x00_disable(ts->ucb);
340}
341
342#ifdef CONFIG_PM
343static int ucb1x00_ts_resume(struct ucb1x00_dev *dev)
344{
345	struct ucb1x00_ts *ts = dev->priv;
346
347	if (ts->rtask != NULL) {
348		/*
349		 * Restart the TS thread to ensure the
350		 * TS interrupt mode is set up again
351		 * after sleep.
352		 */
353		ts->restart = 1;
354		wake_up(&ts->irq_wait);
355	}
356	return 0;
357}
358#else
359#define ucb1x00_ts_resume NULL
360#endif
361
362
363/*
364 * Initialisation.
365 */
366static int ucb1x00_ts_add(struct ucb1x00_dev *dev)
367{
368	struct ucb1x00_ts *ts;
369	struct input_dev *idev;
370	int err;
371
372	ts = kzalloc(sizeof(struct ucb1x00_ts), GFP_KERNEL);
373	idev = input_allocate_device();
374	if (!ts || !idev) {
375		err = -ENOMEM;
376		goto fail;
377	}
378
379	ts->ucb = dev->ucb;
380	ts->idev = idev;
381	ts->adcsync = adcsync ? UCB_SYNC : UCB_NOSYNC;
382
383	idev->name       = "Touchscreen panel";
384	idev->id.product = ts->ucb->id;
385	idev->open       = ucb1x00_ts_open;
386	idev->close      = ucb1x00_ts_close;
387
388	__set_bit(EV_ABS, idev->evbit);
389	__set_bit(ABS_X, idev->absbit);
390	__set_bit(ABS_Y, idev->absbit);
391	__set_bit(ABS_PRESSURE, idev->absbit);
392
393	input_set_drvdata(idev, ts);
394
395	err = input_register_device(idev);
396	if (err)
397		goto fail;
398
399	dev->priv = ts;
400
401	return 0;
402
403 fail:
404	input_free_device(idev);
405	kfree(ts);
406	return err;
407}
408
409static void ucb1x00_ts_remove(struct ucb1x00_dev *dev)
410{
411	struct ucb1x00_ts *ts = dev->priv;
412
413	input_unregister_device(ts->idev);
414	kfree(ts);
415}
416
417static struct ucb1x00_driver ucb1x00_ts_driver = {
418	.add		= ucb1x00_ts_add,
419	.remove		= ucb1x00_ts_remove,
420	.resume		= ucb1x00_ts_resume,
421};
422
423static int __init ucb1x00_ts_init(void)
424{
425	return ucb1x00_register_driver(&ucb1x00_ts_driver);
426}
427
428static void __exit ucb1x00_ts_exit(void)
429{
430	ucb1x00_unregister_driver(&ucb1x00_ts_driver);
431}
432
433module_param(adcsync, int, 0444);
434module_init(ucb1x00_ts_init);
435module_exit(ucb1x00_ts_exit);
436
437MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
438MODULE_DESCRIPTION("UCB1x00 touchscreen driver");
439MODULE_LICENSE("GPL");
440