2 * Touchscreen driver for UCB1x00-based touchscreens
4 * Copyright (C) 2001 Russell King, All Rights Reserved.
5 * Copyright (C) 2005 Pavel Machek
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.
11 * 21-Jan-2002 <jco@ict.es> :
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.
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>
36 #include <mach/collie.h>
37 #include <asm/mach-types.h>
42 struct input_dev
*idev
;
46 unsigned irq_disabled
;
47 wait_queue_head_t irq_wait
;
48 struct task_struct
*rtask
;
52 unsigned int adcsync
:1;
57 static inline void ucb1x00_ts_evt_add(struct ucb1x00_ts
*ts
, u16 pressure
, u16 x
, u16 y
)
59 struct input_dev
*idev
= ts
->idev
;
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);
68 static inline void ucb1x00_ts_event_release(struct ucb1x00_ts
*ts
)
70 struct input_dev
*idev
= ts
->idev
;
72 input_report_abs(idev
, ABS_PRESSURE
, 0);
73 input_report_key(idev
, BTN_TOUCH
, 0);
78 * Switch to interrupt mode.
80 static inline void ucb1x00_ts_mode_int(struct ucb1x00_ts
*ts
)
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
|
89 * Switch to pressure mode, and read pressure. We don't need to wait
90 * here, since both plates are being driven.
92 static inline unsigned int ucb1x00_ts_read_pressure(struct ucb1x00_ts
*ts
)
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
);
102 return ucb1x00_adc_read(ts
->ucb
, UCB_ADC_INP_AD2
, ts
->adcsync
);
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
);
109 return ucb1x00_adc_read(ts
->ucb
, UCB_ADC_INP_TSPY
, ts
->adcsync
);
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.
119 static inline unsigned int ucb1x00_ts_read_xpos(struct ucb1x00_ts
*ts
)
121 if (machine_is_collie())
122 ucb1x00_io_write(ts
->ucb
, 0, COLLIE_TC35143_GPIO_TBL_CHK
);
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
);
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
);
137 return ucb1x00_adc_read(ts
->ucb
, UCB_ADC_INP_TSPY
, ts
->adcsync
);
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.
146 static inline unsigned int ucb1x00_ts_read_ypos(struct ucb1x00_ts
*ts
)
148 if (machine_is_collie())
149 ucb1x00_io_write(ts
->ucb
, 0, COLLIE_TC35143_GPIO_TBL_CHK
);
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
);
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
);
165 return ucb1x00_adc_read(ts
->ucb
, UCB_ADC_INP_TSPX
, ts
->adcsync
);
169 * Switch to X plate resistance mode. Set MX to ground, PX to
170 * supply. Measure current.
172 static inline unsigned int ucb1x00_ts_read_xres(struct ucb1x00_ts
*ts
)
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
);
181 * Switch to Y plate resistance mode. Set MY to ground, PY to
182 * supply. Measure current.
184 static inline unsigned int ucb1x00_ts_read_yres(struct ucb1x00_ts
*ts
)
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
);
192 static inline int ucb1x00_ts_pen_down(struct ucb1x00_ts
*ts
)
194 unsigned int val
= ucb1x00_reg_read(ts
->ucb
, UCB_TS_CR
);
196 if (machine_is_collie())
197 return (!(val
& (UCB_TS_CR_TSPX_LOW
)));
199 return (val
& (UCB_TS_CR_TSPX_LOW
| UCB_TS_CR_TSMX_LOW
));
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).
207 static int ucb1x00_thread(void *_ts
)
209 struct ucb1x00_ts
*ts
= _ts
;
210 DECLARE_WAITQUEUE(wait
, current
);
211 bool frozen
, ignore
= false;
215 add_wait_queue(&ts
->irq_wait
, &wait
);
216 while (!kthread_freezable_should_stop(&frozen
)) {
217 unsigned int x
, y
, p
;
223 ucb1x00_adc_enable(ts
->ucb
);
225 x
= ucb1x00_ts_read_xpos(ts
);
226 y
= ucb1x00_ts_read_ypos(ts
);
227 p
= ucb1x00_ts_read_pressure(ts
);
230 * Switch back to interrupt mode.
232 ucb1x00_ts_mode_int(ts
);
233 ucb1x00_adc_disable(ts
->ucb
);
237 ucb1x00_enable(ts
->ucb
);
240 if (ucb1x00_ts_pen_down(ts
)) {
241 set_current_state(TASK_INTERRUPTIBLE
);
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
);
248 spin_unlock_irq(&ts
->irq_lock
);
249 ucb1x00_disable(ts
->ucb
);
252 * If we spat out a valid sample set last time,
253 * spit out a "pen off" sample here.
256 ucb1x00_ts_event_release(ts
);
260 timeout
= MAX_SCHEDULE_TIMEOUT
;
262 ucb1x00_disable(ts
->ucb
);
265 * Filtering is policy. Policy belongs in user
266 * space. We therefore leave it to user space
267 * to do any filtering they please.
270 ucb1x00_ts_evt_add(ts
, p
, x
, y
);
274 set_current_state(TASK_INTERRUPTIBLE
);
278 schedule_timeout(timeout
);
281 remove_wait_queue(&ts
->irq_wait
, &wait
);
288 * We only detect touch screen _touches_ with this interrupt
289 * handler, and even then we just schedule our task.
291 static irqreturn_t
ucb1x00_ts_irq(int irq
, void *id
)
293 struct ucb1x00_ts
*ts
= id
;
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
);
304 static int ucb1x00_ts_open(struct input_dev
*idev
)
306 struct ucb1x00_ts
*ts
= input_get_drvdata(idev
);
307 unsigned long flags
= 0;
312 if (machine_is_collie())
313 flags
= IRQF_TRIGGER_RISING
;
315 flags
= IRQF_TRIGGER_FALLING
;
317 ts
->irq_disabled
= 0;
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
);
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.
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
);
334 ts
->rtask
= kthread_run(ucb1x00_thread
, ts
, "ktsd");
335 if (!IS_ERR(ts
->rtask
)) {
338 free_irq(ts
->ucb
->irq_base
+ UCB_IRQ_TSPX
, ts
);
348 * Release touchscreen resources. Disable IRQs.
350 static void ucb1x00_ts_close(struct input_dev
*idev
)
352 struct ucb1x00_ts
*ts
= input_get_drvdata(idev
);
355 kthread_stop(ts
->rtask
);
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
);
367 static int ucb1x00_ts_add(struct ucb1x00_dev
*dev
)
369 struct ucb1x00_ts
*ts
;
370 struct input_dev
*idev
;
373 ts
= kzalloc(sizeof(struct ucb1x00_ts
), GFP_KERNEL
);
374 idev
= input_allocate_device();
382 ts
->adcsync
= adcsync
? UCB_SYNC
: UCB_NOSYNC
;
383 spin_lock_init(&ts
->irq_lock
);
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
;
391 idev
->evbit
[0] = BIT_MASK(EV_ABS
) | BIT_MASK(EV_KEY
);
392 idev
->keybit
[BIT_WORD(BTN_TOUCH
)] = BIT_MASK(BTN_TOUCH
);
394 input_set_drvdata(idev
, ts
);
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
);
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);
405 err
= input_register_device(idev
);
414 input_free_device(idev
);
419 static void ucb1x00_ts_remove(struct ucb1x00_dev
*dev
)
421 struct ucb1x00_ts
*ts
= dev
->priv
;
423 input_unregister_device(ts
->idev
);
427 static struct ucb1x00_driver ucb1x00_ts_driver
= {
428 .add
= ucb1x00_ts_add
,
429 .remove
= ucb1x00_ts_remove
,
432 static int __init
ucb1x00_ts_init(void)
434 return ucb1x00_register_driver(&ucb1x00_ts_driver
);
437 static void __exit
ucb1x00_ts_exit(void)
439 ucb1x00_unregister_driver(&ucb1x00_ts_driver
);
442 module_param(adcsync
, int, 0444);
443 module_init(ucb1x00_ts_init
);
444 module_exit(ucb1x00_ts_exit
);
446 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
447 MODULE_DESCRIPTION("UCB1x00 touchscreen driver");
448 MODULE_LICENSE("GPL");