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Russell Kingacb45432005-09-11 10:26:57 +01001/*
Pavel Machek54377752005-09-11 10:28:00 +01002 * Touchscreen driver for UCB1x00-based touchscreens
Russell Kingacb45432005-09-11 10:26:57 +01003 *
4 * Copyright (C) 2001 Russell King, All Rights Reserved.
Pavel Machek54377752005-09-11 10:28:00 +01005 * Copyright (C) 2005 Pavel Machek
Russell Kingacb45432005-09-11 10:26:57 +01006 *
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>
Pavel Machek54377752005-09-11 10:28:00 +010034#include <linux/kthread.h>
Russell Kingacb45432005-09-11 10:26:57 +010035
36#include <asm/dma.h>
37#include <asm/semaphore.h>
Pavel Machek17532982005-10-30 23:38:01 +000038#include <asm/arch/collie.h>
39#include <asm/mach-types.h>
Russell Kingacb45432005-09-11 10:26:57 +010040
41#include "ucb1x00.h"
42
43
44struct ucb1x00_ts {
Dmitry Torokhovbd622662005-09-15 02:01:48 -050045 struct input_dev *idev;
Russell Kingacb45432005-09-11 10:26:57 +010046 struct ucb1x00 *ucb;
47
48 wait_queue_head_t irq_wait;
Russell Kingacb45432005-09-11 10:26:57 +010049 struct task_struct *rtask;
Russell Kingacb45432005-09-11 10:26:57 +010050 u16 x_res;
51 u16 y_res;
52
Russell King6b9ea422005-09-24 10:24:37 +010053 unsigned int restart:1;
54 unsigned int adcsync:1;
Russell Kingacb45432005-09-11 10:26:57 +010055};
56
57static int adcsync;
58
59static inline void ucb1x00_ts_evt_add(struct ucb1x00_ts *ts, u16 pressure, u16 x, u16 y)
60{
Nicolas Pitre1393c3e2005-12-12 00:37:36 -080061 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);
Russell Kingacb45432005-09-11 10:26:57 +010066}
67
68static inline void ucb1x00_ts_event_release(struct ucb1x00_ts *ts)
69{
Nicolas Pitre1393c3e2005-12-12 00:37:36 -080070 struct input_dev *idev = ts->idev;
71 input_report_abs(idev, ABS_PRESSURE, 0);
72 input_sync(idev);
Russell Kingacb45432005-09-11 10:26:57 +010073}
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{
Pavel Machek17532982005-10-30 23:38:01 +000092 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);
Russell Kingacb45432005-09-11 10:26:57 +010097
Pavel Machek17532982005-10-30 23:38:01 +000098 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 }
Russell Kingacb45432005-09-11 10:26:57 +0100109}
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{
Pavel Machek17532982005-10-30 23:38:01 +0000119 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 }
Russell Kingacb45432005-09-11 10:26:57 +0100129 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{
Pavel Machek17532982005-10-30 23:38:01 +0000146 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
Russell Kingacb45432005-09-11 10:26:57 +0100157 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
Pavel Machek17532982005-10-30 23:38:01 +0000190static 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
Russell Kingacb45432005-09-11 10:26:57 +0100199/*
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 */
204static 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
Russell Kingacb45432005-09-11 10:26:57 +0100211 /*
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
Russell Kingacb45432005-09-11 10:26:57 +0100218 valid = 0;
219
220 add_wait_queue(&ts->irq_wait, &wait);
Pavel Machek54377752005-09-11 10:28:00 +0100221 while (!kthread_should_stop()) {
Pavel Machek17532982005-10-30 23:38:01 +0000222 unsigned int x, y, p;
Russell Kingacb45432005-09-11 10:26:57 +0100223 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
Pavel Machek54377752005-09-11 10:28:00 +0100239 msleep(10);
Russell Kingacb45432005-09-11 10:26:57 +0100240
241 ucb1x00_enable(ts->ucb);
Russell Kingacb45432005-09-11 10:26:57 +0100242
Pavel Machek17532982005-10-30 23:38:01 +0000243
244 if (ucb1x00_ts_pen_down(ts)) {
Russell Kingacb45432005-09-11 10:26:57 +0100245 set_task_state(tsk, TASK_INTERRUPTIBLE);
246
Pavel Machek17532982005-10-30 23:38:01 +0000247 ucb1x00_enable_irq(ts->ucb, UCB_IRQ_TSPX, machine_is_collie() ? UCB_RISING : UCB_FALLING);
Russell Kingacb45432005-09-11 10:26:57 +0100248 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);
Russell Kingacb45432005-09-11 10:26:57 +0100280 }
281
282 remove_wait_queue(&ts->irq_wait, &wait);
283
284 ts->rtask = NULL;
Pavel Machek54377752005-09-11 10:28:00 +0100285 return 0;
Russell Kingacb45432005-09-11 10:26:57 +0100286}
287
288/*
289 * We only detect touch screen _touches_ with this interrupt
290 * handler, and even then we just schedule our task.
291 */
292static 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
299static int ucb1x00_ts_open(struct input_dev *idev)
300{
Nicolas Pitre1393c3e2005-12-12 00:37:36 -0800301 struct ucb1x00_ts *ts = idev->private;
Russell Kingacb45432005-09-11 10:26:57 +0100302 int ret = 0;
303
Pavel Machek54377752005-09-11 10:28:00 +0100304 BUG_ON(ts->rtask);
Russell Kingacb45432005-09-11 10:26:57 +0100305
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
Pavel Machek54377752005-09-11 10:28:00 +0100320 ts->rtask = kthread_run(ucb1x00_thread, ts, "ktsd");
321 if (!IS_ERR(ts->rtask)) {
Russell Kingacb45432005-09-11 10:26:57 +0100322 ret = 0;
323 } else {
324 ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts);
Pavel Machek54377752005-09-11 10:28:00 +0100325 ts->rtask = NULL;
326 ret = -EFAULT;
Russell Kingacb45432005-09-11 10:26:57 +0100327 }
328
329 out:
Russell Kingacb45432005-09-11 10:26:57 +0100330 return ret;
331}
332
333/*
334 * Release touchscreen resources. Disable IRQs.
335 */
336static void ucb1x00_ts_close(struct input_dev *idev)
337{
Nicolas Pitre1393c3e2005-12-12 00:37:36 -0800338 struct ucb1x00_ts *ts = idev->private;
Russell Kingacb45432005-09-11 10:26:57 +0100339
Pavel Machek54377752005-09-11 10:28:00 +0100340 if (ts->rtask)
341 kthread_stop(ts->rtask);
Russell Kingacb45432005-09-11 10:26:57 +0100342
Pavel Machek54377752005-09-11 10:28:00 +0100343 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);
Russell Kingacb45432005-09-11 10:26:57 +0100347}
348
349#ifdef CONFIG_PM
350static 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 */
373static int ucb1x00_ts_add(struct ucb1x00_dev *dev)
374{
375 struct ucb1x00_ts *ts;
376
Dmitry Torokhovbd622662005-09-15 02:01:48 -0500377 ts = kzalloc(sizeof(struct ucb1x00_ts), GFP_KERNEL);
Russell Kingacb45432005-09-11 10:26:57 +0100378 if (!ts)
379 return -ENOMEM;
380
Dmitry Torokhovbd622662005-09-15 02:01:48 -0500381 ts->idev = input_allocate_device();
382 if (!ts->idev) {
383 kfree(ts);
384 return -ENOMEM;
385 }
Russell Kingacb45432005-09-11 10:26:57 +0100386
387 ts->ucb = dev->ucb;
388 ts->adcsync = adcsync ? UCB_SYNC : UCB_NOSYNC;
Russell Kingacb45432005-09-11 10:26:57 +0100389
Nicolas Pitre1393c3e2005-12-12 00:37:36 -0800390 ts->idev->private = ts;
Dmitry Torokhovbd622662005-09-15 02:01:48 -0500391 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;
Russell Kingacb45432005-09-11 10:26:57 +0100395
Dmitry Torokhovbd622662005-09-15 02:01:48 -0500396 __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);
Russell Kingacb45432005-09-11 10:26:57 +0100400
Dmitry Torokhovbd622662005-09-15 02:01:48 -0500401 input_register_device(ts->idev);
Russell Kingacb45432005-09-11 10:26:57 +0100402
403 dev->priv = ts;
404
405 return 0;
406}
407
408static void ucb1x00_ts_remove(struct ucb1x00_dev *dev)
409{
410 struct ucb1x00_ts *ts = dev->priv;
Dmitry Torokhovbd622662005-09-15 02:01:48 -0500411
412 input_unregister_device(ts->idev);
Russell Kingacb45432005-09-11 10:26:57 +0100413 kfree(ts);
414}
415
416static struct ucb1x00_driver ucb1x00_ts_driver = {
417 .add = ucb1x00_ts_add,
418 .remove = ucb1x00_ts_remove,
419 .resume = ucb1x00_ts_resume,
420};
421
422static int __init ucb1x00_ts_init(void)
423{
424 return ucb1x00_register_driver(&ucb1x00_ts_driver);
425}
426
427static void __exit ucb1x00_ts_exit(void)
428{
429 ucb1x00_unregister_driver(&ucb1x00_ts_driver);
430}
431
432module_param(adcsync, int, 0444);
433module_init(ucb1x00_ts_init);
434module_exit(ucb1x00_ts_exit);
435
436MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
437MODULE_DESCRIPTION("UCB1x00 touchscreen driver");
438MODULE_LICENSE("GPL");