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Merge tag 'block-5.11-2021-01-10' of git://git.kernel.dk/linux-block
[linux/fpc-iii.git] / drivers / mfd / ucb1x00-ts.c
blob6e1b38f9f26c656a169421a3bd862b704e9b70b6
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Touchscreen driver for UCB1x00-based touchscreens
4 *
5 * Copyright (C) 2001 Russell King, All Rights Reserved.
6 * Copyright (C) 2005 Pavel Machek
7 *
8 * 21-Jan-2002 <jco@ict.es> :
9 *
10 * Added support for synchronous A/D mode. This mode is useful to
11 * avoid noise induced in the touchpanel by the LCD, provided that
12 * the UCB1x00 has a valid LCD sync signal routed to its ADCSYNC pin.
13 * It is important to note that the signal connected to the ADCSYNC
14 * pin should provide pulses even when the LCD is blanked, otherwise
15 * a pen touch needed to unblank the LCD will never be read.
16 */
17 #include <linux/module.h>
18 #include <linux/moduleparam.h>
19 #include <linux/init.h>
20 #include <linux/interrupt.h>
21 #include <linux/sched.h>
22 #include <linux/spinlock.h>
23 #include <linux/completion.h>
24 #include <linux/delay.h>
25 #include <linux/string.h>
26 #include <linux/input.h>
27 #include <linux/device.h>
28 #include <linux/freezer.h>
29 #include <linux/slab.h>
30 #include <linux/kthread.h>
31 #include <linux/mfd/ucb1x00.h>
32
33 #include <mach/collie.h>
34 #include <asm/mach-types.h>
35
36
37
38 struct ucb1x00_ts {
39 struct input_dev *idev;
40 struct ucb1x00 *ucb;
41
42 spinlock_t irq_lock;
43 unsigned irq_disabled;
44 wait_queue_head_t irq_wait;
45 struct task_struct *rtask;
46 u16 x_res;
47 u16 y_res;
48
49 unsigned int adcsync:1;
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 {
56 struct input_dev *idev = ts->idev;
57
58 input_report_abs(idev, ABS_X, x);
59 input_report_abs(idev, ABS_Y, y);
60 input_report_abs(idev, ABS_PRESSURE, pressure);
61 input_report_key(idev, BTN_TOUCH, 1);
62 input_sync(idev);
63 }
64
65 static inline void ucb1x00_ts_event_release(struct ucb1x00_ts *ts)
66 {
67 struct input_dev *idev = ts->idev;
68
69 input_report_abs(idev, ABS_PRESSURE, 0);
70 input_report_key(idev, BTN_TOUCH, 0);
71 input_sync(idev);
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 {
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 }
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 {
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 }
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 {
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
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
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);
192
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
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;
207 DECLARE_WAITQUEUE(wait, current);
208 bool frozen, ignore = false;
209 int valid = 0;
210
211 set_freezable();
212 add_wait_queue(&ts->irq_wait, &wait);
213 while (!kthread_freezable_should_stop(&frozen)) {
214 unsigned int x, y, p;
215 signed long timeout;
216
217 if (frozen)
218 ignore = true;
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
232 msleep(10);
233
234 ucb1x00_enable(ts->ucb);
235
236
237 if (ucb1x00_ts_pen_down(ts)) {
238 set_current_state(TASK_INTERRUPTIBLE);
239
240 spin_lock_irq(&ts->irq_lock);
241 if (ts->irq_disabled) {
242 ts->irq_disabled = 0;
243 enable_irq(ts->ucb->irq_base + UCB_IRQ_TSPX);
244 }
245 spin_unlock_irq(&ts->irq_lock);
246 ucb1x00_disable(ts->ucb);
247
248 /*
249 * If we spat out a valid sample set last time,
250 * spit out a "pen off" sample here.
251 */
252 if (valid) {
253 ucb1x00_ts_event_release(ts);
254 valid = 0;
255 }
256
257 timeout = MAX_SCHEDULE_TIMEOUT;
258 } else {
259 ucb1x00_disable(ts->ucb);
260
261 /*
262 * Filtering is policy. Policy belongs in user
263 * space. We therefore leave it to user space
264 * to do any filtering they please.
265 */
266 if (!ignore) {
267 ucb1x00_ts_evt_add(ts, p, x, y);
268 valid = 1;
269 }
270
271 set_current_state(TASK_INTERRUPTIBLE);
272 timeout = HZ / 100;
273 }
274
275 schedule_timeout(timeout);
276 }
277
278 remove_wait_queue(&ts->irq_wait, &wait);
279
280 ts->rtask = NULL;
281 return 0;
282 }
283
284 /*
285 * We only detect touch screen _touches_ with this interrupt
286 * handler, and even then we just schedule our task.
287 */
288 static irqreturn_t ucb1x00_ts_irq(int irq, void *id)
289 {
290 struct ucb1x00_ts *ts = id;
291
292 spin_lock(&ts->irq_lock);
293 ts->irq_disabled = 1;
294 disable_irq_nosync(ts->ucb->irq_base + UCB_IRQ_TSPX);
295 spin_unlock(&ts->irq_lock);
296 wake_up(&ts->irq_wait);
297
298 return IRQ_HANDLED;
299 }
300
301 static int ucb1x00_ts_open(struct input_dev *idev)
302 {
303 struct ucb1x00_ts *ts = input_get_drvdata(idev);
304 unsigned long flags = 0;
305 int ret = 0;
306
307 BUG_ON(ts->rtask);
308
309 if (machine_is_collie())
310 flags = IRQF_TRIGGER_RISING;
311 else
312 flags = IRQF_TRIGGER_FALLING;
313
314 ts->irq_disabled = 0;
315
316 init_waitqueue_head(&ts->irq_wait);
317 ret = request_irq(ts->ucb->irq_base + UCB_IRQ_TSPX, ucb1x00_ts_irq,
318 flags, "ucb1x00-ts", ts);
319 if (ret < 0)
320 goto out;
321
322 /*
323 * If we do this at all, we should allow the user to
324 * measure and read the X and Y resistance at any time.
325 */
326 ucb1x00_adc_enable(ts->ucb);
327 ts->x_res = ucb1x00_ts_read_xres(ts);
328 ts->y_res = ucb1x00_ts_read_yres(ts);
329 ucb1x00_adc_disable(ts->ucb);
330
331 ts->rtask = kthread_run(ucb1x00_thread, ts, "ktsd");
332 if (!IS_ERR(ts->rtask)) {
333 ret = 0;
334 } else {
335 free_irq(ts->ucb->irq_base + UCB_IRQ_TSPX, ts);
336 ts->rtask = NULL;
337 ret = -EFAULT;
338 }
339
340 out:
341 return ret;
342 }
343
344 /*
345 * Release touchscreen resources. Disable IRQs.
346 */
347 static void ucb1x00_ts_close(struct input_dev *idev)
348 {
349 struct ucb1x00_ts *ts = input_get_drvdata(idev);
350
351 if (ts->rtask)
352 kthread_stop(ts->rtask);
353
354 ucb1x00_enable(ts->ucb);
355 free_irq(ts->ucb->irq_base + UCB_IRQ_TSPX, ts);
356 ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 0);
357 ucb1x00_disable(ts->ucb);
358 }
359
360
361 /*
362 * Initialisation.
363 */
364 static int ucb1x00_ts_add(struct ucb1x00_dev *dev)
365 {
366 struct ucb1x00_ts *ts;
367 struct input_dev *idev;
368 int err;
369
370 ts = kzalloc(sizeof(struct ucb1x00_ts), GFP_KERNEL);
371 idev = input_allocate_device();
372 if (!ts || !idev) {
373 err = -ENOMEM;
374 goto fail;
375 }
376
377 ts->ucb = dev->ucb;
378 ts->idev = idev;
379 ts->adcsync = adcsync ? UCB_SYNC : UCB_NOSYNC;
380 spin_lock_init(&ts->irq_lock);
381
382 idev->name = "Touchscreen panel";
383 idev->id.product = ts->ucb->id;
384 idev->open = ucb1x00_ts_open;
385 idev->close = ucb1x00_ts_close;
386 idev->dev.parent = &ts->ucb->dev;
387
388 idev->evbit[0] = BIT_MASK(EV_ABS) | BIT_MASK(EV_KEY);
389 idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
390
391 input_set_drvdata(idev, ts);
392
393 ucb1x00_adc_enable(ts->ucb);
394 ts->x_res = ucb1x00_ts_read_xres(ts);
395 ts->y_res = ucb1x00_ts_read_yres(ts);
396 ucb1x00_adc_disable(ts->ucb);
397
398 input_set_abs_params(idev, ABS_X, 0, ts->x_res, 0, 0);
399 input_set_abs_params(idev, ABS_Y, 0, ts->y_res, 0, 0);
400 input_set_abs_params(idev, ABS_PRESSURE, 0, 0, 0, 0);
401
402 err = input_register_device(idev);
403 if (err)
404 goto fail;
405
406 dev->priv = ts;
407
408 return 0;
409
410 fail:
411 input_free_device(idev);
412 kfree(ts);
413 return err;
414 }
415
416 static void ucb1x00_ts_remove(struct ucb1x00_dev *dev)
417 {
418 struct ucb1x00_ts *ts = dev->priv;
419
420 input_unregister_device(ts->idev);
421 kfree(ts);
422 }
423
424 static struct ucb1x00_driver ucb1x00_ts_driver = {
425 .add = ucb1x00_ts_add,
426 .remove = ucb1x00_ts_remove,
427 };
428
429 static int __init ucb1x00_ts_init(void)
430 {
431 return ucb1x00_register_driver(&ucb1x00_ts_driver);
432 }
433
434 static void __exit ucb1x00_ts_exit(void)
435 {
436 ucb1x00_unregister_driver(&ucb1x00_ts_driver);
437 }
438
439 module_param(adcsync, int, 0444);
440 module_init(ucb1x00_ts_init);
441 module_exit(ucb1x00_ts_exit);
442
443 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
444 MODULE_DESCRIPTION("UCB1x00 touchscreen driver");
445 MODULE_LICENSE("GPL");
Linux with added FPC-III support