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/interrupt.h>
24 #include <linux/sched.h>
25 #include <linux/spinlock.h>
26 #include <linux/completion.h>
27 #include <linux/delay.h>
28 #include <linux/string.h>
29 #include <linux/input.h>
30 #include <linux/device.h>
31 #include <linux/freezer.h>
32 #include <linux/slab.h>
33 #include <linux/kthread.h>
34 #include <linux/mfd/ucb1x00.h>
35
36 #include <mach/collie.h>
37 #include <asm/mach-types.h>
38
39
40
41 struct ucb1x00_ts {
42 struct input_dev *idev;
43 struct ucb1x00 *ucb;
44
45 spinlock_t irq_lock;
46 unsigned irq_disabled;
47 wait_queue_head_t irq_wait;
48 struct task_struct *rtask;
49 u16 x_res;
50 u16 y_res;
51
52 unsigned int adcsync:1;
53 };
54
55 static int adcsync;
56
ucb1x00_ts_evt_add(struct ucb1x00_ts * ts,u16 pressure,u16 x,u16 y)57 static 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_report_key(idev, BTN_TOUCH, 1);
65 input_sync(idev);
66 }
67
ucb1x00_ts_event_release(struct ucb1x00_ts * ts)68 static inline void ucb1x00_ts_event_release(struct ucb1x00_ts *ts)
69 {
70 struct input_dev *idev = ts->idev;
71
72 input_report_abs(idev, ABS_PRESSURE, 0);
73 input_report_key(idev, BTN_TOUCH, 0);
74 input_sync(idev);
75 }
76
77 /*
78 * Switch to interrupt mode.
79 */
ucb1x00_ts_mode_int(struct ucb1x00_ts * ts)80 static inline void ucb1x00_ts_mode_int(struct ucb1x00_ts *ts)
81 {
82 ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
83 UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW |
84 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |
85 UCB_TS_CR_MODE_INT);
86 }
87
88 /*
89 * Switch to pressure mode, and read pressure. We don't need to wait
90 * here, since both plates are being driven.
91 */
ucb1x00_ts_read_pressure(struct ucb1x00_ts * ts)92 static inline unsigned int ucb1x00_ts_read_pressure(struct ucb1x00_ts *ts)
93 {
94 if (machine_is_collie()) {
95 ucb1x00_io_write(ts->ucb, COLLIE_TC35143_GPIO_TBL_CHK, 0);
96 ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
97 UCB_TS_CR_TSPX_POW | UCB_TS_CR_TSMX_POW |
98 UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);
99
100 udelay(55);
101
102 return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_AD2, ts->adcsync);
103 } else {
104 ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
105 UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW |
106 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |
107 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
108
109 return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPY, ts->adcsync);
110 }
111 }
112
113 /*
114 * Switch to X position mode and measure Y plate. We switch the plate
115 * configuration in pressure mode, then switch to position mode. This
116 * gives a faster response time. Even so, we need to wait about 55us
117 * for things to stabilise.
118 */
ucb1x00_ts_read_xpos(struct ucb1x00_ts * ts)119 static inline unsigned int ucb1x00_ts_read_xpos(struct ucb1x00_ts *ts)
120 {
121 if (machine_is_collie())
122 ucb1x00_io_write(ts->ucb, 0, COLLIE_TC35143_GPIO_TBL_CHK);
123 else {
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 ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
128 UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
129 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
130 }
131 ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
132 UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
133 UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);
134
135 udelay(55);
136
137 return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPY, ts->adcsync);
138 }
139
140 /*
141 * Switch to Y position mode and measure X plate. We switch the plate
142 * configuration in pressure mode, then switch to position mode. This
143 * gives a faster response time. Even so, we need to wait about 55us
144 * for things to stabilise.
145 */
ucb1x00_ts_read_ypos(struct ucb1x00_ts * ts)146 static inline unsigned int ucb1x00_ts_read_ypos(struct ucb1x00_ts *ts)
147 {
148 if (machine_is_collie())
149 ucb1x00_io_write(ts->ucb, 0, COLLIE_TC35143_GPIO_TBL_CHK);
150 else {
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 ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
155 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
156 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
157 }
158
159 ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
160 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
161 UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);
162
163 udelay(55);
164
165 return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPX, ts->adcsync);
166 }
167
168 /*
169 * Switch to X plate resistance mode. Set MX to ground, PX to
170 * supply. Measure current.
171 */
ucb1x00_ts_read_xres(struct ucb1x00_ts * ts)172 static inline unsigned int ucb1x00_ts_read_xres(struct ucb1x00_ts *ts)
173 {
174 ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
175 UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
176 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
177 return ucb1x00_adc_read(ts->ucb, 0, ts->adcsync);
178 }
179
180 /*
181 * Switch to Y plate resistance mode. Set MY to ground, PY to
182 * supply. Measure current.
183 */
ucb1x00_ts_read_yres(struct ucb1x00_ts * ts)184 static inline unsigned int ucb1x00_ts_read_yres(struct ucb1x00_ts *ts)
185 {
186 ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
187 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
188 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
189 return ucb1x00_adc_read(ts->ucb, 0, ts->adcsync);
190 }
191
ucb1x00_ts_pen_down(struct ucb1x00_ts * ts)192 static inline int ucb1x00_ts_pen_down(struct ucb1x00_ts *ts)
193 {
194 unsigned int val = ucb1x00_reg_read(ts->ucb, UCB_TS_CR);
195
196 if (machine_is_collie())
197 return (!(val & (UCB_TS_CR_TSPX_LOW)));
198 else
199 return (val & (UCB_TS_CR_TSPX_LOW | UCB_TS_CR_TSMX_LOW));
200 }
201
202 /*
203 * This is a RT kernel thread that handles the ADC accesses
204 * (mainly so we can use semaphores in the UCB1200 core code
205 * to serialise accesses to the ADC).
206 */
ucb1x00_thread(void * _ts)207 static int ucb1x00_thread(void *_ts)
208 {
209 struct ucb1x00_ts *ts = _ts;
210 DECLARE_WAITQUEUE(wait, current);
211 bool frozen, ignore = false;
212 int valid = 0;
213
214 set_freezable();
215 add_wait_queue(&ts->irq_wait, &wait);
216 while (!kthread_freezable_should_stop(&frozen)) {
217 unsigned int x, y, p;
218 signed long timeout;
219
220 if (frozen)
221 ignore = true;
222
223 ucb1x00_adc_enable(ts->ucb);
224
225 x = ucb1x00_ts_read_xpos(ts);
226 y = ucb1x00_ts_read_ypos(ts);
227 p = ucb1x00_ts_read_pressure(ts);
228
229 /*
230 * Switch back to interrupt mode.
231 */
232 ucb1x00_ts_mode_int(ts);
233 ucb1x00_adc_disable(ts->ucb);
234
235 msleep(10);
236
237 ucb1x00_enable(ts->ucb);
238
239
240 if (ucb1x00_ts_pen_down(ts)) {
241 set_current_state(TASK_INTERRUPTIBLE);
242
243 spin_lock_irq(&ts->irq_lock);
244 if (ts->irq_disabled) {
245 ts->irq_disabled = 0;
246 enable_irq(ts->ucb->irq_base + UCB_IRQ_TSPX);
247 }
248 spin_unlock_irq(&ts->irq_lock);
249 ucb1x00_disable(ts->ucb);
250
251 /*
252 * If we spat out a valid sample set last time,
253 * spit out a "pen off" sample here.
254 */
255 if (valid) {
256 ucb1x00_ts_event_release(ts);
257 valid = 0;
258 }
259
260 timeout = MAX_SCHEDULE_TIMEOUT;
261 } else {
262 ucb1x00_disable(ts->ucb);
263
264 /*
265 * Filtering is policy. Policy belongs in user
266 * space. We therefore leave it to user space
267 * to do any filtering they please.
268 */
269 if (!ignore) {
270 ucb1x00_ts_evt_add(ts, p, x, y);
271 valid = 1;
272 }
273
274 set_current_state(TASK_INTERRUPTIBLE);
275 timeout = HZ / 100;
276 }
277
278 schedule_timeout(timeout);
279 }
280
281 remove_wait_queue(&ts->irq_wait, &wait);
282
283 ts->rtask = NULL;
284 return 0;
285 }
286
287 /*
288 * We only detect touch screen _touches_ with this interrupt
289 * handler, and even then we just schedule our task.
290 */
ucb1x00_ts_irq(int irq,void * id)291 static irqreturn_t ucb1x00_ts_irq(int irq, void *id)
292 {
293 struct ucb1x00_ts *ts = id;
294
295 spin_lock(&ts->irq_lock);
296 ts->irq_disabled = 1;
297 disable_irq_nosync(ts->ucb->irq_base + UCB_IRQ_TSPX);
298 spin_unlock(&ts->irq_lock);
299 wake_up(&ts->irq_wait);
300
301 return IRQ_HANDLED;
302 }
303
ucb1x00_ts_open(struct input_dev * idev)304 static int ucb1x00_ts_open(struct input_dev *idev)
305 {
306 struct ucb1x00_ts *ts = input_get_drvdata(idev);
307 unsigned long flags = 0;
308 int ret = 0;
309
310 BUG_ON(ts->rtask);
311
312 if (machine_is_collie())
313 flags = IRQF_TRIGGER_RISING;
314 else
315 flags = IRQF_TRIGGER_FALLING;
316
317 ts->irq_disabled = 0;
318
319 init_waitqueue_head(&ts->irq_wait);
320 ret = request_irq(ts->ucb->irq_base + UCB_IRQ_TSPX, ucb1x00_ts_irq,
321 flags, "ucb1x00-ts", ts);
322 if (ret < 0)
323 goto out;
324
325 /*
326 * If we do this at all, we should allow the user to
327 * measure and read the X and Y resistance at any time.
328 */
329 ucb1x00_adc_enable(ts->ucb);
330 ts->x_res = ucb1x00_ts_read_xres(ts);
331 ts->y_res = ucb1x00_ts_read_yres(ts);
332 ucb1x00_adc_disable(ts->ucb);
333
334 ts->rtask = kthread_run(ucb1x00_thread, ts, "ktsd");
335 if (!IS_ERR(ts->rtask)) {
336 ret = 0;
337 } else {
338 free_irq(ts->ucb->irq_base + UCB_IRQ_TSPX, ts);
339 ts->rtask = NULL;
340 ret = -EFAULT;
341 }
342
343 out:
344 return ret;
345 }
346
347 /*
348 * Release touchscreen resources. Disable IRQs.
349 */
ucb1x00_ts_close(struct input_dev * idev)350 static void ucb1x00_ts_close(struct input_dev *idev)
351 {
352 struct ucb1x00_ts *ts = input_get_drvdata(idev);
353
354 if (ts->rtask)
355 kthread_stop(ts->rtask);
356
357 ucb1x00_enable(ts->ucb);
358 free_irq(ts->ucb->irq_base + UCB_IRQ_TSPX, ts);
359 ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 0);
360 ucb1x00_disable(ts->ucb);
361 }
362
363
364 /*
365 * Initialisation.
366 */
ucb1x00_ts_add(struct ucb1x00_dev * dev)367 static int ucb1x00_ts_add(struct ucb1x00_dev *dev)
368 {
369 struct ucb1x00_ts *ts;
370 struct input_dev *idev;
371 int err;
372
373 ts = kzalloc(sizeof(struct ucb1x00_ts), GFP_KERNEL);
374 idev = input_allocate_device();
375 if (!ts || !idev) {
376 err = -ENOMEM;
377 goto fail;
378 }
379
380 ts->ucb = dev->ucb;
381 ts->idev = idev;
382 ts->adcsync = adcsync ? UCB_SYNC : UCB_NOSYNC;
383 spin_lock_init(&ts->irq_lock);
384
385 idev->name = "Touchscreen panel";
386 idev->id.product = ts->ucb->id;
387 idev->open = ucb1x00_ts_open;
388 idev->close = ucb1x00_ts_close;
389 idev->dev.parent = &ts->ucb->dev;
390
391 idev->evbit[0] = BIT_MASK(EV_ABS) | BIT_MASK(EV_KEY);
392 idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
393
394 input_set_drvdata(idev, ts);
395
396 ucb1x00_adc_enable(ts->ucb);
397 ts->x_res = ucb1x00_ts_read_xres(ts);
398 ts->y_res = ucb1x00_ts_read_yres(ts);
399 ucb1x00_adc_disable(ts->ucb);
400
401 input_set_abs_params(idev, ABS_X, 0, ts->x_res, 0, 0);
402 input_set_abs_params(idev, ABS_Y, 0, ts->y_res, 0, 0);
403 input_set_abs_params(idev, ABS_PRESSURE, 0, 0, 0, 0);
404
405 err = input_register_device(idev);
406 if (err)
407 goto fail;
408
409 dev->priv = ts;
410
411 return 0;
412
413 fail:
414 input_free_device(idev);
415 kfree(ts);
416 return err;
417 }
418
ucb1x00_ts_remove(struct ucb1x00_dev * dev)419 static void ucb1x00_ts_remove(struct ucb1x00_dev *dev)
420 {
421 struct ucb1x00_ts *ts = dev->priv;
422
423 input_unregister_device(ts->idev);
424 kfree(ts);
425 }
426
427 static struct ucb1x00_driver ucb1x00_ts_driver = {
428 .add = ucb1x00_ts_add,
429 .remove = ucb1x00_ts_remove,
430 };
431
ucb1x00_ts_init(void)432 static int __init ucb1x00_ts_init(void)
433 {
434 return ucb1x00_register_driver(&ucb1x00_ts_driver);
435 }
436
ucb1x00_ts_exit(void)437 static void __exit ucb1x00_ts_exit(void)
438 {
439 ucb1x00_unregister_driver(&ucb1x00_ts_driver);
440 }
441
442 module_param(adcsync, int, 0444);
443 module_init(ucb1x00_ts_init);
444 module_exit(ucb1x00_ts_exit);
445
446 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
447 MODULE_DESCRIPTION("UCB1x00 touchscreen driver");
448 MODULE_LICENSE("GPL");
449
