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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 */
Russell Kingacb45432005-09-11 10:26:57 +010020#include <linux/module.h>
21#include <linux/moduleparam.h>
22#include <linux/init.h>
23#include <linux/smp.h>
Russell Kingacb45432005-09-11 10:26:57 +010024#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>
Nigel Cunningham7dfb7102006-12-06 20:34:23 -080030#include <linux/freezer.h>
Russell Kingacb45432005-09-11 10:26:57 +010031#include <linux/slab.h>
Pavel Machek54377752005-09-11 10:28:00 +010032#include <linux/kthread.h>
Russell Kingacb45432005-09-11 10:26:57 +010033
34#include <asm/dma.h>
Russell Kinga09e64f2008-08-05 16:14:15 +010035#include <mach/collie.h>
Pavel Machek17532982005-10-30 23:38:01 +000036#include <asm/mach-types.h>
Russell Kingacb45432005-09-11 10:26:57 +010037
38#include "ucb1x00.h"
39
40
41struct ucb1x00_ts {
Dmitry Torokhovbd622662005-09-15 02:01:48 -050042 struct input_dev *idev;
Russell Kingacb45432005-09-11 10:26:57 +010043 struct ucb1x00 *ucb;
44
45 wait_queue_head_t irq_wait;
Russell Kingacb45432005-09-11 10:26:57 +010046 struct task_struct *rtask;
Russell Kingacb45432005-09-11 10:26:57 +010047 u16 x_res;
48 u16 y_res;
49
Russell King6b9ea422005-09-24 10:24:37 +010050 unsigned int restart:1;
51 unsigned int adcsync:1;
Russell Kingacb45432005-09-11 10:26:57 +010052};
53
54static int adcsync;
55
56static inline void ucb1x00_ts_evt_add(struct ucb1x00_ts *ts, u16 pressure, u16 x, u16 y)
57{
Nicolas Pitre1393c3e2005-12-12 00:37:36 -080058 struct input_dev *idev = ts->idev;
Dmitry Torokhov08c67d22006-09-29 01:59:52 -070059
Nicolas Pitre1393c3e2005-12-12 00:37:36 -080060 input_report_abs(idev, ABS_X, x);
61 input_report_abs(idev, ABS_Y, y);
62 input_report_abs(idev, ABS_PRESSURE, pressure);
63 input_sync(idev);
Russell Kingacb45432005-09-11 10:26:57 +010064}
65
66static inline void ucb1x00_ts_event_release(struct ucb1x00_ts *ts)
67{
Nicolas Pitre1393c3e2005-12-12 00:37:36 -080068 struct input_dev *idev = ts->idev;
Dmitry Torokhov08c67d22006-09-29 01:59:52 -070069
Nicolas Pitre1393c3e2005-12-12 00:37:36 -080070 input_report_abs(idev, ABS_PRESSURE, 0);
71 input_sync(idev);
Russell Kingacb45432005-09-11 10:26:57 +010072}
73
74/*
75 * Switch to interrupt mode.
76 */
77static 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 */
89static inline unsigned int ucb1x00_ts_read_pressure(struct ucb1x00_ts *ts)
90{
Pavel Machek17532982005-10-30 23:38:01 +000091 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);
Russell Kingacb45432005-09-11 10:26:57 +010096
Pavel Machek17532982005-10-30 23:38:01 +000097 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 }
Russell Kingacb45432005-09-11 10:26:57 +0100108}
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 */
116static inline unsigned int ucb1x00_ts_read_xpos(struct ucb1x00_ts *ts)
117{
Pavel Machek17532982005-10-30 23:38:01 +0000118 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 }
Russell Kingacb45432005-09-11 10:26:57 +0100128 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 */
143static inline unsigned int ucb1x00_ts_read_ypos(struct ucb1x00_ts *ts)
144{
Pavel Machek17532982005-10-30 23:38:01 +0000145 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
Russell Kingacb45432005-09-11 10:26:57 +0100156 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 */
169static 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 */
181static 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
Pavel Machek17532982005-10-30 23:38:01 +0000189static inline int ucb1x00_ts_pen_down(struct ucb1x00_ts *ts)
190{
191 unsigned int val = ucb1x00_reg_read(ts->ucb, UCB_TS_CR);
Dmitry Torokhov08c67d22006-09-29 01:59:52 -0700192
Pavel Machek17532982005-10-30 23:38:01 +0000193 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;
Robert P. J. Dayf7440b02008-04-28 02:14:24 -0700207 DECLARE_WAITQUEUE(wait, current);
Dmitry Torokhov1124d5c2007-05-14 23:52:22 -0400208 int valid = 0;
Russell Kingacb45432005-09-11 10:26:57 +0100209
Rafael J. Wysocki83144182007-07-17 04:03:35 -0700210 set_freezable();
Russell Kingacb45432005-09-11 10:26:57 +0100211 add_wait_queue(&ts->irq_wait, &wait);
Pavel Machek54377752005-09-11 10:28:00 +0100212 while (!kthread_should_stop()) {
Pavel Machek17532982005-10-30 23:38:01 +0000213 unsigned int x, y, p;
Russell Kingacb45432005-09-11 10:26:57 +0100214 signed long timeout;
215
216 ts->restart = 0;
217
218 ucb1x00_adc_enable(ts->ucb);
219
220 x = ucb1x00_ts_read_xpos(ts);
221 y = ucb1x00_ts_read_ypos(ts);
222 p = ucb1x00_ts_read_pressure(ts);
223
224 /*
225 * Switch back to interrupt mode.
226 */
227 ucb1x00_ts_mode_int(ts);
228 ucb1x00_adc_disable(ts->ucb);
229
Pavel Machek54377752005-09-11 10:28:00 +0100230 msleep(10);
Russell Kingacb45432005-09-11 10:26:57 +0100231
232 ucb1x00_enable(ts->ucb);
Russell Kingacb45432005-09-11 10:26:57 +0100233
Pavel Machek17532982005-10-30 23:38:01 +0000234
235 if (ucb1x00_ts_pen_down(ts)) {
Robert P. J. Dayf7440b02008-04-28 02:14:24 -0700236 set_current_state(TASK_INTERRUPTIBLE);
Russell Kingacb45432005-09-11 10:26:57 +0100237
Pavel Machek17532982005-10-30 23:38:01 +0000238 ucb1x00_enable_irq(ts->ucb, UCB_IRQ_TSPX, machine_is_collie() ? UCB_RISING : UCB_FALLING);
Russell Kingacb45432005-09-11 10:26:57 +0100239 ucb1x00_disable(ts->ucb);
240
241 /*
242 * If we spat out a valid sample set last time,
243 * spit out a "pen off" sample here.
244 */
245 if (valid) {
246 ucb1x00_ts_event_release(ts);
247 valid = 0;
248 }
249
250 timeout = MAX_SCHEDULE_TIMEOUT;
251 } else {
252 ucb1x00_disable(ts->ucb);
253
254 /*
255 * Filtering is policy. Policy belongs in user
256 * space. We therefore leave it to user space
257 * to do any filtering they please.
258 */
259 if (!ts->restart) {
260 ucb1x00_ts_evt_add(ts, p, x, y);
261 valid = 1;
262 }
263
Robert P. J. Dayf7440b02008-04-28 02:14:24 -0700264 set_current_state(TASK_INTERRUPTIBLE);
Russell Kingacb45432005-09-11 10:26:57 +0100265 timeout = HZ / 100;
266 }
267
268 try_to_freeze();
269
270 schedule_timeout(timeout);
Russell Kingacb45432005-09-11 10:26:57 +0100271 }
272
273 remove_wait_queue(&ts->irq_wait, &wait);
274
275 ts->rtask = NULL;
Pavel Machek54377752005-09-11 10:28:00 +0100276 return 0;
Russell Kingacb45432005-09-11 10:26:57 +0100277}
278
279/*
280 * We only detect touch screen _touches_ with this interrupt
281 * handler, and even then we just schedule our task.
282 */
283static void ucb1x00_ts_irq(int idx, void *id)
284{
285 struct ucb1x00_ts *ts = id;
Dmitry Torokhov08c67d22006-09-29 01:59:52 -0700286
Russell Kingacb45432005-09-11 10:26:57 +0100287 ucb1x00_disable_irq(ts->ucb, UCB_IRQ_TSPX, UCB_FALLING);
288 wake_up(&ts->irq_wait);
289}
290
291static int ucb1x00_ts_open(struct input_dev *idev)
292{
Dmitry Torokhov26be5a52007-05-11 01:16:12 -0400293 struct ucb1x00_ts *ts = input_get_drvdata(idev);
Russell Kingacb45432005-09-11 10:26:57 +0100294 int ret = 0;
295
Pavel Machek54377752005-09-11 10:28:00 +0100296 BUG_ON(ts->rtask);
Russell Kingacb45432005-09-11 10:26:57 +0100297
298 init_waitqueue_head(&ts->irq_wait);
299 ret = ucb1x00_hook_irq(ts->ucb, UCB_IRQ_TSPX, ucb1x00_ts_irq, ts);
300 if (ret < 0)
301 goto out;
302
303 /*
304 * If we do this at all, we should allow the user to
305 * measure and read the X and Y resistance at any time.
306 */
307 ucb1x00_adc_enable(ts->ucb);
308 ts->x_res = ucb1x00_ts_read_xres(ts);
309 ts->y_res = ucb1x00_ts_read_yres(ts);
310 ucb1x00_adc_disable(ts->ucb);
311
Pavel Machek54377752005-09-11 10:28:00 +0100312 ts->rtask = kthread_run(ucb1x00_thread, ts, "ktsd");
313 if (!IS_ERR(ts->rtask)) {
Russell Kingacb45432005-09-11 10:26:57 +0100314 ret = 0;
315 } else {
316 ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts);
Pavel Machek54377752005-09-11 10:28:00 +0100317 ts->rtask = NULL;
318 ret = -EFAULT;
Russell Kingacb45432005-09-11 10:26:57 +0100319 }
320
321 out:
Russell Kingacb45432005-09-11 10:26:57 +0100322 return ret;
323}
324
325/*
326 * Release touchscreen resources. Disable IRQs.
327 */
328static void ucb1x00_ts_close(struct input_dev *idev)
329{
Dmitry Torokhov26be5a52007-05-11 01:16:12 -0400330 struct ucb1x00_ts *ts = input_get_drvdata(idev);
Russell Kingacb45432005-09-11 10:26:57 +0100331
Pavel Machek54377752005-09-11 10:28:00 +0100332 if (ts->rtask)
333 kthread_stop(ts->rtask);
Russell Kingacb45432005-09-11 10:26:57 +0100334
Pavel Machek54377752005-09-11 10:28:00 +0100335 ucb1x00_enable(ts->ucb);
336 ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts);
337 ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 0);
338 ucb1x00_disable(ts->ucb);
Russell Kingacb45432005-09-11 10:26:57 +0100339}
340
341#ifdef CONFIG_PM
342static int ucb1x00_ts_resume(struct ucb1x00_dev *dev)
343{
344 struct ucb1x00_ts *ts = dev->priv;
345
346 if (ts->rtask != NULL) {
347 /*
348 * Restart the TS thread to ensure the
349 * TS interrupt mode is set up again
350 * after sleep.
351 */
352 ts->restart = 1;
353 wake_up(&ts->irq_wait);
354 }
355 return 0;
356}
357#else
358#define ucb1x00_ts_resume NULL
359#endif
360
361
362/*
363 * Initialisation.
364 */
365static int ucb1x00_ts_add(struct ucb1x00_dev *dev)
366{
367 struct ucb1x00_ts *ts;
Dmitry Torokhov08c67d22006-09-29 01:59:52 -0700368 struct input_dev *idev;
369 int err;
Russell Kingacb45432005-09-11 10:26:57 +0100370
Dmitry Torokhovbd622662005-09-15 02:01:48 -0500371 ts = kzalloc(sizeof(struct ucb1x00_ts), GFP_KERNEL);
Dmitry Torokhov08c67d22006-09-29 01:59:52 -0700372 idev = input_allocate_device();
373 if (!ts || !idev) {
374 err = -ENOMEM;
375 goto fail;
Dmitry Torokhovbd622662005-09-15 02:01:48 -0500376 }
Russell Kingacb45432005-09-11 10:26:57 +0100377
378 ts->ucb = dev->ucb;
Dmitry Torokhov08c67d22006-09-29 01:59:52 -0700379 ts->idev = idev;
Russell Kingacb45432005-09-11 10:26:57 +0100380 ts->adcsync = adcsync ? UCB_SYNC : UCB_NOSYNC;
Russell Kingacb45432005-09-11 10:26:57 +0100381
Dmitry Torokhov08c67d22006-09-29 01:59:52 -0700382 idev->name = "Touchscreen panel";
383 idev->id.product = ts->ucb->id;
384 idev->open = ucb1x00_ts_open;
385 idev->close = ucb1x00_ts_close;
Russell Kingacb45432005-09-11 10:26:57 +0100386
Dmitry Torokhov08c67d22006-09-29 01:59:52 -0700387 __set_bit(EV_ABS, idev->evbit);
388 __set_bit(ABS_X, idev->absbit);
389 __set_bit(ABS_Y, idev->absbit);
390 __set_bit(ABS_PRESSURE, idev->absbit);
Russell Kingacb45432005-09-11 10:26:57 +0100391
Dmitry Torokhov26be5a52007-05-11 01:16:12 -0400392 input_set_drvdata(idev, ts);
393
Dmitry Torokhov08c67d22006-09-29 01:59:52 -0700394 err = input_register_device(idev);
395 if (err)
396 goto fail;
Russell Kingacb45432005-09-11 10:26:57 +0100397
398 dev->priv = ts;
399
400 return 0;
Dmitry Torokhov08c67d22006-09-29 01:59:52 -0700401
402 fail:
403 input_free_device(idev);
404 kfree(ts);
405 return err;
Russell Kingacb45432005-09-11 10:26:57 +0100406}
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");