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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>
38
39#include "ucb1x00.h"
40
41
42struct ucb1x00_ts {
Dmitry Torokhovbd622662005-09-15 02:01:48 -050043 struct input_dev *idev;
Russell Kingacb45432005-09-11 10:26:57 +010044 struct ucb1x00 *ucb;
45
46 wait_queue_head_t irq_wait;
Russell Kingacb45432005-09-11 10:26:57 +010047 struct task_struct *rtask;
Russell Kingacb45432005-09-11 10:26:57 +010048 u16 x_res;
49 u16 y_res;
50
Russell King6b9ea422005-09-24 10:24:37 +010051 unsigned int restart:1;
52 unsigned int adcsync:1;
Russell Kingacb45432005-09-11 10:26:57 +010053};
54
55static int adcsync;
56
57static inline void ucb1x00_ts_evt_add(struct ucb1x00_ts *ts, u16 pressure, u16 x, u16 y)
58{
Dmitry Torokhovbd622662005-09-15 02:01:48 -050059 input_report_abs(ts->idev, ABS_X, x);
60 input_report_abs(ts->idev, ABS_Y, y);
61 input_report_abs(ts->idev, ABS_PRESSURE, pressure);
62 input_sync(ts->idev);
Russell Kingacb45432005-09-11 10:26:57 +010063}
64
65static inline void ucb1x00_ts_event_release(struct ucb1x00_ts *ts)
66{
Dmitry Torokhovbd622662005-09-15 02:01:48 -050067 input_report_abs(ts->idev, ABS_PRESSURE, 0);
68 input_sync(ts->idev);
Russell Kingacb45432005-09-11 10:26:57 +010069}
70
71/*
72 * Switch to interrupt mode.
73 */
74static inline void ucb1x00_ts_mode_int(struct ucb1x00_ts *ts)
75{
76 ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
77 UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW |
78 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |
79 UCB_TS_CR_MODE_INT);
80}
81
82/*
83 * Switch to pressure mode, and read pressure. We don't need to wait
84 * here, since both plates are being driven.
85 */
86static inline unsigned int ucb1x00_ts_read_pressure(struct ucb1x00_ts *ts)
87{
88 ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
89 UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW |
90 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |
91 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
92
93 return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPY, ts->adcsync);
94}
95
96/*
97 * Switch to X position mode and measure Y plate. We switch the plate
98 * configuration in pressure mode, then switch to position mode. This
99 * gives a faster response time. Even so, we need to wait about 55us
100 * for things to stabilise.
101 */
102static inline unsigned int ucb1x00_ts_read_xpos(struct ucb1x00_ts *ts)
103{
104 ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
105 UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
106 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
107 ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
108 UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
109 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
110 ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
111 UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
112 UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);
113
114 udelay(55);
115
116 return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPY, ts->adcsync);
117}
118
119/*
120 * Switch to Y position mode and measure X plate. We switch the plate
121 * configuration in pressure mode, then switch to position mode. This
122 * gives a faster response time. Even so, we need to wait about 55us
123 * for things to stabilise.
124 */
125static inline unsigned int ucb1x00_ts_read_ypos(struct ucb1x00_ts *ts)
126{
127 ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
128 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
129 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
130 ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
131 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
132 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
133 ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
134 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
135 UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);
136
137 udelay(55);
138
139 return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPX, ts->adcsync);
140}
141
142/*
143 * Switch to X plate resistance mode. Set MX to ground, PX to
144 * supply. Measure current.
145 */
146static inline unsigned int ucb1x00_ts_read_xres(struct ucb1x00_ts *ts)
147{
148 ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
149 UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
150 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
151 return ucb1x00_adc_read(ts->ucb, 0, ts->adcsync);
152}
153
154/*
155 * Switch to Y plate resistance mode. Set MY to ground, PY to
156 * supply. Measure current.
157 */
158static inline unsigned int ucb1x00_ts_read_yres(struct ucb1x00_ts *ts)
159{
160 ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
161 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
162 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
163 return ucb1x00_adc_read(ts->ucb, 0, ts->adcsync);
164}
165
166/*
167 * This is a RT kernel thread that handles the ADC accesses
168 * (mainly so we can use semaphores in the UCB1200 core code
169 * to serialise accesses to the ADC).
170 */
171static int ucb1x00_thread(void *_ts)
172{
173 struct ucb1x00_ts *ts = _ts;
174 struct task_struct *tsk = current;
175 DECLARE_WAITQUEUE(wait, tsk);
176 int valid;
177
Russell Kingacb45432005-09-11 10:26:57 +0100178 /*
179 * We could run as a real-time thread. However, thus far
180 * this doesn't seem to be necessary.
181 */
182// tsk->policy = SCHED_FIFO;
183// tsk->rt_priority = 1;
184
Russell Kingacb45432005-09-11 10:26:57 +0100185 valid = 0;
186
187 add_wait_queue(&ts->irq_wait, &wait);
Pavel Machek54377752005-09-11 10:28:00 +0100188 while (!kthread_should_stop()) {
Russell Kingacb45432005-09-11 10:26:57 +0100189 unsigned int x, y, p, val;
190 signed long timeout;
191
192 ts->restart = 0;
193
194 ucb1x00_adc_enable(ts->ucb);
195
196 x = ucb1x00_ts_read_xpos(ts);
197 y = ucb1x00_ts_read_ypos(ts);
198 p = ucb1x00_ts_read_pressure(ts);
199
200 /*
201 * Switch back to interrupt mode.
202 */
203 ucb1x00_ts_mode_int(ts);
204 ucb1x00_adc_disable(ts->ucb);
205
Pavel Machek54377752005-09-11 10:28:00 +0100206 msleep(10);
Russell Kingacb45432005-09-11 10:26:57 +0100207
208 ucb1x00_enable(ts->ucb);
209 val = ucb1x00_reg_read(ts->ucb, UCB_TS_CR);
210
211 if (val & (UCB_TS_CR_TSPX_LOW | UCB_TS_CR_TSMX_LOW)) {
212 set_task_state(tsk, TASK_INTERRUPTIBLE);
213
214 ucb1x00_enable_irq(ts->ucb, UCB_IRQ_TSPX, UCB_FALLING);
215 ucb1x00_disable(ts->ucb);
216
217 /*
218 * If we spat out a valid sample set last time,
219 * spit out a "pen off" sample here.
220 */
221 if (valid) {
222 ucb1x00_ts_event_release(ts);
223 valid = 0;
224 }
225
226 timeout = MAX_SCHEDULE_TIMEOUT;
227 } else {
228 ucb1x00_disable(ts->ucb);
229
230 /*
231 * Filtering is policy. Policy belongs in user
232 * space. We therefore leave it to user space
233 * to do any filtering they please.
234 */
235 if (!ts->restart) {
236 ucb1x00_ts_evt_add(ts, p, x, y);
237 valid = 1;
238 }
239
240 set_task_state(tsk, TASK_INTERRUPTIBLE);
241 timeout = HZ / 100;
242 }
243
244 try_to_freeze();
245
246 schedule_timeout(timeout);
Russell Kingacb45432005-09-11 10:26:57 +0100247 }
248
249 remove_wait_queue(&ts->irq_wait, &wait);
250
251 ts->rtask = NULL;
Pavel Machek54377752005-09-11 10:28:00 +0100252 return 0;
Russell Kingacb45432005-09-11 10:26:57 +0100253}
254
255/*
256 * We only detect touch screen _touches_ with this interrupt
257 * handler, and even then we just schedule our task.
258 */
259static void ucb1x00_ts_irq(int idx, void *id)
260{
261 struct ucb1x00_ts *ts = id;
262 ucb1x00_disable_irq(ts->ucb, UCB_IRQ_TSPX, UCB_FALLING);
263 wake_up(&ts->irq_wait);
264}
265
266static int ucb1x00_ts_open(struct input_dev *idev)
267{
268 struct ucb1x00_ts *ts = (struct ucb1x00_ts *)idev;
269 int ret = 0;
270
Pavel Machek54377752005-09-11 10:28:00 +0100271 BUG_ON(ts->rtask);
Russell Kingacb45432005-09-11 10:26:57 +0100272
273 init_waitqueue_head(&ts->irq_wait);
274 ret = ucb1x00_hook_irq(ts->ucb, UCB_IRQ_TSPX, ucb1x00_ts_irq, ts);
275 if (ret < 0)
276 goto out;
277
278 /*
279 * If we do this at all, we should allow the user to
280 * measure and read the X and Y resistance at any time.
281 */
282 ucb1x00_adc_enable(ts->ucb);
283 ts->x_res = ucb1x00_ts_read_xres(ts);
284 ts->y_res = ucb1x00_ts_read_yres(ts);
285 ucb1x00_adc_disable(ts->ucb);
286
Pavel Machek54377752005-09-11 10:28:00 +0100287 ts->rtask = kthread_run(ucb1x00_thread, ts, "ktsd");
288 if (!IS_ERR(ts->rtask)) {
Russell Kingacb45432005-09-11 10:26:57 +0100289 ret = 0;
290 } else {
291 ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts);
Pavel Machek54377752005-09-11 10:28:00 +0100292 ts->rtask = NULL;
293 ret = -EFAULT;
Russell Kingacb45432005-09-11 10:26:57 +0100294 }
295
296 out:
Russell Kingacb45432005-09-11 10:26:57 +0100297 return ret;
298}
299
300/*
301 * Release touchscreen resources. Disable IRQs.
302 */
303static void ucb1x00_ts_close(struct input_dev *idev)
304{
305 struct ucb1x00_ts *ts = (struct ucb1x00_ts *)idev;
306
Pavel Machek54377752005-09-11 10:28:00 +0100307 if (ts->rtask)
308 kthread_stop(ts->rtask);
Russell Kingacb45432005-09-11 10:26:57 +0100309
Pavel Machek54377752005-09-11 10:28:00 +0100310 ucb1x00_enable(ts->ucb);
311 ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts);
312 ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 0);
313 ucb1x00_disable(ts->ucb);
Russell Kingacb45432005-09-11 10:26:57 +0100314}
315
316#ifdef CONFIG_PM
317static int ucb1x00_ts_resume(struct ucb1x00_dev *dev)
318{
319 struct ucb1x00_ts *ts = dev->priv;
320
321 if (ts->rtask != NULL) {
322 /*
323 * Restart the TS thread to ensure the
324 * TS interrupt mode is set up again
325 * after sleep.
326 */
327 ts->restart = 1;
328 wake_up(&ts->irq_wait);
329 }
330 return 0;
331}
332#else
333#define ucb1x00_ts_resume NULL
334#endif
335
336
337/*
338 * Initialisation.
339 */
340static int ucb1x00_ts_add(struct ucb1x00_dev *dev)
341{
342 struct ucb1x00_ts *ts;
343
Dmitry Torokhovbd622662005-09-15 02:01:48 -0500344 ts = kzalloc(sizeof(struct ucb1x00_ts), GFP_KERNEL);
Russell Kingacb45432005-09-11 10:26:57 +0100345 if (!ts)
346 return -ENOMEM;
347
Dmitry Torokhovbd622662005-09-15 02:01:48 -0500348 ts->idev = input_allocate_device();
349 if (!ts->idev) {
350 kfree(ts);
351 return -ENOMEM;
352 }
Russell Kingacb45432005-09-11 10:26:57 +0100353
354 ts->ucb = dev->ucb;
355 ts->adcsync = adcsync ? UCB_SYNC : UCB_NOSYNC;
Russell Kingacb45432005-09-11 10:26:57 +0100356
Dmitry Torokhovbd622662005-09-15 02:01:48 -0500357 ts->idev->name = "Touchscreen panel";
358 ts->idev->id.product = ts->ucb->id;
359 ts->idev->open = ucb1x00_ts_open;
360 ts->idev->close = ucb1x00_ts_close;
Russell Kingacb45432005-09-11 10:26:57 +0100361
Dmitry Torokhovbd622662005-09-15 02:01:48 -0500362 __set_bit(EV_ABS, ts->idev->evbit);
363 __set_bit(ABS_X, ts->idev->absbit);
364 __set_bit(ABS_Y, ts->idev->absbit);
365 __set_bit(ABS_PRESSURE, ts->idev->absbit);
Russell Kingacb45432005-09-11 10:26:57 +0100366
Dmitry Torokhovbd622662005-09-15 02:01:48 -0500367 input_register_device(ts->idev);
Russell Kingacb45432005-09-11 10:26:57 +0100368
369 dev->priv = ts;
370
371 return 0;
372}
373
374static void ucb1x00_ts_remove(struct ucb1x00_dev *dev)
375{
376 struct ucb1x00_ts *ts = dev->priv;
Dmitry Torokhovbd622662005-09-15 02:01:48 -0500377
378 input_unregister_device(ts->idev);
Russell Kingacb45432005-09-11 10:26:57 +0100379 kfree(ts);
380}
381
382static struct ucb1x00_driver ucb1x00_ts_driver = {
383 .add = ucb1x00_ts_add,
384 .remove = ucb1x00_ts_remove,
385 .resume = ucb1x00_ts_resume,
386};
387
388static int __init ucb1x00_ts_init(void)
389{
390 return ucb1x00_register_driver(&ucb1x00_ts_driver);
391}
392
393static void __exit ucb1x00_ts_exit(void)
394{
395 ucb1x00_unregister_driver(&ucb1x00_ts_driver);
396}
397
398module_param(adcsync, int, 0444);
399module_init(ucb1x00_ts_init);
400module_exit(ucb1x00_ts_exit);
401
402MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
403MODULE_DESCRIPTION("UCB1x00 touchscreen driver");
404MODULE_LICENSE("GPL");