2 * Philips UCB1400 touchscreen driver
4 * Author: Nicolas Pitre
5 * Created: September 25, 2006
6 * Copyright: MontaVista Software, Inc.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
12 * This code is heavily based on ucb1x00-*.c copyrighted by Russell King
13 * covering the UCB1100, UCB1200 and UCB1300.. Support for the UCB1400 has
14 * been made separate from ucb1x00-core/ucb1x00-ts on Russell's request.
17 #include <linux/module.h>
18 #include <linux/moduleparam.h>
19 #include <linux/init.h>
20 #include <linux/completion.h>
21 #include <linux/delay.h>
22 #include <linux/input.h>
23 #include <linux/device.h>
24 #include <linux/interrupt.h>
25 #include <linux/suspend.h>
26 #include <linux/slab.h>
27 #include <linux/kthread.h>
28 #include <linux/freezer.h>
30 #include <sound/core.h>
31 #include <sound/ac97_codec.h>
35 * Interesting UCB1400 AC-link registers
38 #define UCB_IE_RIS 0x5e
39 #define UCB_IE_FAL 0x60
40 #define UCB_IE_STATUS 0x62
41 #define UCB_IE_CLEAR 0x62
42 #define UCB_IE_ADC (1 << 11)
43 #define UCB_IE_TSPX (1 << 12)
45 #define UCB_TS_CR 0x64
46 #define UCB_TS_CR_TSMX_POW (1 << 0)
47 #define UCB_TS_CR_TSPX_POW (1 << 1)
48 #define UCB_TS_CR_TSMY_POW (1 << 2)
49 #define UCB_TS_CR_TSPY_POW (1 << 3)
50 #define UCB_TS_CR_TSMX_GND (1 << 4)
51 #define UCB_TS_CR_TSPX_GND (1 << 5)
52 #define UCB_TS_CR_TSMY_GND (1 << 6)
53 #define UCB_TS_CR_TSPY_GND (1 << 7)
54 #define UCB_TS_CR_MODE_INT (0 << 8)
55 #define UCB_TS_CR_MODE_PRES (1 << 8)
56 #define UCB_TS_CR_MODE_POS (2 << 8)
57 #define UCB_TS_CR_BIAS_ENA (1 << 11)
58 #define UCB_TS_CR_TSPX_LOW (1 << 12)
59 #define UCB_TS_CR_TSMX_LOW (1 << 13)
61 #define UCB_ADC_CR 0x66
62 #define UCB_ADC_SYNC_ENA (1 << 0)
63 #define UCB_ADC_VREFBYP_CON (1 << 1)
64 #define UCB_ADC_INP_TSPX (0 << 2)
65 #define UCB_ADC_INP_TSMX (1 << 2)
66 #define UCB_ADC_INP_TSPY (2 << 2)
67 #define UCB_ADC_INP_TSMY (3 << 2)
68 #define UCB_ADC_INP_AD0 (4 << 2)
69 #define UCB_ADC_INP_AD1 (5 << 2)
70 #define UCB_ADC_INP_AD2 (6 << 2)
71 #define UCB_ADC_INP_AD3 (7 << 2)
72 #define UCB_ADC_EXT_REF (1 << 5)
73 #define UCB_ADC_START (1 << 7)
74 #define UCB_ADC_ENA (1 << 15)
76 #define UCB_ADC_DATA 0x68
77 #define UCB_ADC_DAT_VALID (1 << 15)
78 #define UCB_ADC_DAT_VALUE(x) ((x) & 0x3ff)
81 #define UCB_ID_1400 0x4304
85 struct snd_ac97 *ac97;
86 struct input_dev *ts_idev;
90 wait_queue_head_t ts_wait;
91 struct task_struct *ts_task;
93 unsigned int irq_pending; /* not bit field shared */
94 unsigned int ts_restart:1;
95 unsigned int adcsync:1;
99 static int ts_delay = 55; /* us */
100 static int ts_delay_pressure; /* us */
102 static inline u16 ucb1400_reg_read(struct ucb1400 *ucb, u16 reg)
104 return ucb->ac97->bus->ops->read(ucb->ac97, reg);
107 static inline void ucb1400_reg_write(struct ucb1400 *ucb, u16 reg, u16 val)
109 ucb->ac97->bus->ops->write(ucb->ac97, reg, val);
112 static inline void ucb1400_adc_enable(struct ucb1400 *ucb)
114 ucb1400_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA);
117 static unsigned int ucb1400_adc_read(struct ucb1400 *ucb, u16 adc_channel)
122 adc_channel |= UCB_ADC_SYNC_ENA;
124 ucb1400_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA | adc_channel);
125 ucb1400_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA | adc_channel | UCB_ADC_START);
128 val = ucb1400_reg_read(ucb, UCB_ADC_DATA);
129 if (val & UCB_ADC_DAT_VALID)
131 /* yield to other processes */
132 schedule_timeout_uninterruptible(1);
135 return UCB_ADC_DAT_VALUE(val);
138 static inline void ucb1400_adc_disable(struct ucb1400 *ucb)
140 ucb1400_reg_write(ucb, UCB_ADC_CR, 0);
143 /* Switch to interrupt mode. */
144 static inline void ucb1400_ts_mode_int(struct ucb1400 *ucb)
146 ucb1400_reg_write(ucb, UCB_TS_CR,
147 UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW |
148 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |
153 * Switch to pressure mode, and read pressure. We don't need to wait
154 * here, since both plates are being driven.
156 static inline unsigned int ucb1400_ts_read_pressure(struct ucb1400 *ucb)
158 ucb1400_reg_write(ucb, UCB_TS_CR,
159 UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW |
160 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |
161 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
162 udelay(ts_delay_pressure);
163 return ucb1400_adc_read(ucb, UCB_ADC_INP_TSPY);
167 * Switch to X position mode and measure Y plate. We switch the plate
168 * configuration in pressure mode, then switch to position mode. This
169 * gives a faster response time. Even so, we need to wait about 55us
170 * for things to stabilise.
172 static inline unsigned int ucb1400_ts_read_xpos(struct ucb1400 *ucb)
174 ucb1400_reg_write(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 ucb1400_reg_write(ucb, UCB_TS_CR,
178 UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
179 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
180 ucb1400_reg_write(ucb, UCB_TS_CR,
181 UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
182 UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);
186 return ucb1400_adc_read(ucb, UCB_ADC_INP_TSPY);
190 * Switch to Y position mode and measure X plate. We switch the plate
191 * configuration in pressure mode, then switch to position mode. This
192 * gives a faster response time. Even so, we need to wait about 55us
193 * for things to stabilise.
195 static inline unsigned int ucb1400_ts_read_ypos(struct ucb1400 *ucb)
197 ucb1400_reg_write(ucb, UCB_TS_CR,
198 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
199 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
200 ucb1400_reg_write(ucb, UCB_TS_CR,
201 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
202 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
203 ucb1400_reg_write(ucb, UCB_TS_CR,
204 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
205 UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);
209 return ucb1400_adc_read(ucb, UCB_ADC_INP_TSPX);
213 * Switch to X plate resistance mode. Set MX to ground, PX to
214 * supply. Measure current.
216 static inline unsigned int ucb1400_ts_read_xres(struct ucb1400 *ucb)
218 ucb1400_reg_write(ucb, UCB_TS_CR,
219 UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
220 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
221 return ucb1400_adc_read(ucb, 0);
225 * Switch to Y plate resistance mode. Set MY to ground, PY to
226 * supply. Measure current.
228 static inline unsigned int ucb1400_ts_read_yres(struct ucb1400 *ucb)
230 ucb1400_reg_write(ucb, UCB_TS_CR,
231 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
232 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
233 return ucb1400_adc_read(ucb, 0);
236 static inline int ucb1400_ts_pen_down(struct ucb1400 *ucb)
238 unsigned short val = ucb1400_reg_read(ucb, UCB_TS_CR);
239 return (val & (UCB_TS_CR_TSPX_LOW | UCB_TS_CR_TSMX_LOW));
242 static inline void ucb1400_ts_irq_enable(struct ucb1400 *ucb)
244 ucb1400_reg_write(ucb, UCB_IE_CLEAR, UCB_IE_TSPX);
245 ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0);
246 ucb1400_reg_write(ucb, UCB_IE_FAL, UCB_IE_TSPX);
249 static inline void ucb1400_ts_irq_disable(struct ucb1400 *ucb)
251 ucb1400_reg_write(ucb, UCB_IE_FAL, 0);
254 static void ucb1400_ts_evt_add(struct input_dev *idev, u16 pressure, u16 x, u16 y)
256 input_report_abs(idev, ABS_X, x);
257 input_report_abs(idev, ABS_Y, y);
258 input_report_abs(idev, ABS_PRESSURE, pressure);
262 static void ucb1400_ts_event_release(struct input_dev *idev)
264 input_report_abs(idev, ABS_PRESSURE, 0);
268 static void ucb1400_handle_pending_irq(struct ucb1400 *ucb)
272 isr = ucb1400_reg_read(ucb, UCB_IE_STATUS);
273 ucb1400_reg_write(ucb, UCB_IE_CLEAR, isr);
274 ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0);
276 if (isr & UCB_IE_TSPX)
277 ucb1400_ts_irq_disable(ucb);
279 printk(KERN_ERR "ucb1400: unexpected IE_STATUS = %#x\n", isr);
281 enable_irq(ucb->irq);
284 static int ucb1400_ts_thread(void *_ucb)
286 struct ucb1400 *ucb = _ucb;
287 struct task_struct *tsk = current;
289 struct sched_param param = { .sched_priority = 1 };
291 sched_setscheduler(tsk, SCHED_FIFO, ¶m);
294 while (!kthread_should_stop()) {
295 unsigned int x, y, p;
300 if (ucb->irq_pending) {
301 ucb->irq_pending = 0;
302 ucb1400_handle_pending_irq(ucb);
305 ucb1400_adc_enable(ucb);
306 x = ucb1400_ts_read_xpos(ucb);
307 y = ucb1400_ts_read_ypos(ucb);
308 p = ucb1400_ts_read_pressure(ucb);
309 ucb1400_adc_disable(ucb);
311 /* Switch back to interrupt mode. */
312 ucb1400_ts_mode_int(ucb);
316 if (ucb1400_ts_pen_down(ucb)) {
317 ucb1400_ts_irq_enable(ucb);
320 * If we spat out a valid sample set last time,
321 * spit out a "pen off" sample here.
324 ucb1400_ts_event_release(ucb->ts_idev);
328 timeout = MAX_SCHEDULE_TIMEOUT;
331 ucb1400_ts_evt_add(ucb->ts_idev, p, x, y);
332 timeout = msecs_to_jiffies(10);
335 wait_event_freezable_timeout(ucb->ts_wait,
336 ucb->irq_pending || ucb->ts_restart || kthread_should_stop(),
340 /* Send the "pen off" if we are stopping with the pen still active */
342 ucb1400_ts_event_release(ucb->ts_idev);
349 * A restriction with interrupts exists when using the ucb1400, as
350 * the codec read/write routines may sleep while waiting for codec
351 * access completion and uses semaphores for access control to the
352 * AC97 bus. A complete codec read cycle could take anywhere from
353 * 60 to 100uSec so we *definitely* don't want to spin inside the
354 * interrupt handler waiting for codec access. So, we handle the
355 * interrupt by scheduling a RT kernel thread to run in process
356 * context instead of interrupt context.
358 static irqreturn_t ucb1400_hard_irq(int irqnr, void *devid)
360 struct ucb1400 *ucb = devid;
362 if (irqnr == ucb->irq) {
363 disable_irq(ucb->irq);
364 ucb->irq_pending = 1;
365 wake_up(&ucb->ts_wait);
371 static int ucb1400_ts_open(struct input_dev *idev)
373 struct ucb1400 *ucb = input_get_drvdata(idev);
376 BUG_ON(ucb->ts_task);
378 ucb->ts_task = kthread_run(ucb1400_ts_thread, ucb, "UCB1400_ts");
379 if (IS_ERR(ucb->ts_task)) {
380 ret = PTR_ERR(ucb->ts_task);
387 static void ucb1400_ts_close(struct input_dev *idev)
389 struct ucb1400 *ucb = input_get_drvdata(idev);
392 kthread_stop(ucb->ts_task);
394 ucb1400_ts_irq_disable(ucb);
395 ucb1400_reg_write(ucb, UCB_TS_CR, 0);
399 static int ucb1400_ts_resume(struct device *dev)
401 struct ucb1400 *ucb = dev_get_drvdata(dev);
405 * Restart the TS thread to ensure the
406 * TS interrupt mode is set up again
410 wake_up(&ucb->ts_wait);
415 #define ucb1400_ts_resume NULL
423 * Try to probe our interrupt, rather than relying on lots of
424 * hard-coded machine dependencies.
426 static int ucb1400_detect_irq(struct ucb1400 *ucb)
428 unsigned long mask, timeout;
430 mask = probe_irq_on();
436 /* Enable the ADC interrupt. */
437 ucb1400_reg_write(ucb, UCB_IE_RIS, UCB_IE_ADC);
438 ucb1400_reg_write(ucb, UCB_IE_FAL, UCB_IE_ADC);
439 ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0xffff);
440 ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0);
442 /* Cause an ADC interrupt. */
443 ucb1400_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA);
444 ucb1400_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA | UCB_ADC_START);
446 /* Wait for the conversion to complete. */
447 timeout = jiffies + HZ/2;
448 while (!(ucb1400_reg_read(ucb, UCB_ADC_DATA) & UCB_ADC_DAT_VALID)) {
450 if (time_after(jiffies, timeout)) {
451 printk(KERN_ERR "ucb1400: timed out in IRQ probe\n");
456 ucb1400_reg_write(ucb, UCB_ADC_CR, 0);
458 /* Disable and clear interrupt. */
459 ucb1400_reg_write(ucb, UCB_IE_RIS, 0);
460 ucb1400_reg_write(ucb, UCB_IE_FAL, 0);
461 ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0xffff);
462 ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0);
464 /* Read triggered interrupt. */
465 ucb->irq = probe_irq_off(mask);
466 if (ucb->irq < 0 || ucb->irq == NO_IRQ)
472 static int ucb1400_ts_probe(struct device *dev)
475 struct input_dev *idev;
476 int error, id, x_res, y_res;
478 ucb = kzalloc(sizeof(struct ucb1400), GFP_KERNEL);
479 idev = input_allocate_device();
486 ucb->adcsync = adcsync;
487 ucb->ac97 = to_ac97_t(dev);
488 init_waitqueue_head(&ucb->ts_wait);
490 id = ucb1400_reg_read(ucb, UCB_ID);
491 if (id != UCB_ID_1400) {
496 error = ucb1400_detect_irq(ucb);
498 printk(KERN_ERR "UCB1400: IRQ probe failed\n");
502 error = request_irq(ucb->irq, ucb1400_hard_irq, IRQF_TRIGGER_RISING,
505 printk(KERN_ERR "ucb1400: unable to grab irq%d: %d\n",
509 printk(KERN_DEBUG "UCB1400: found IRQ %d\n", ucb->irq);
511 input_set_drvdata(idev, ucb);
513 idev->dev.parent = dev;
514 idev->name = "UCB1400 touchscreen interface";
515 idev->id.vendor = ucb1400_reg_read(ucb, AC97_VENDOR_ID1);
516 idev->id.product = id;
517 idev->open = ucb1400_ts_open;
518 idev->close = ucb1400_ts_close;
519 idev->evbit[0] = BIT_MASK(EV_ABS);
521 ucb1400_adc_enable(ucb);
522 x_res = ucb1400_ts_read_xres(ucb);
523 y_res = ucb1400_ts_read_yres(ucb);
524 ucb1400_adc_disable(ucb);
525 printk(KERN_DEBUG "UCB1400: x/y = %d/%d\n", x_res, y_res);
527 input_set_abs_params(idev, ABS_X, 0, x_res, 0, 0);
528 input_set_abs_params(idev, ABS_Y, 0, y_res, 0, 0);
529 input_set_abs_params(idev, ABS_PRESSURE, 0, 0, 0, 0);
531 error = input_register_device(idev);
535 dev_set_drvdata(dev, ucb);
539 free_irq(ucb->irq, ucb);
541 input_free_device(idev);
546 static int ucb1400_ts_remove(struct device *dev)
548 struct ucb1400 *ucb = dev_get_drvdata(dev);
550 free_irq(ucb->irq, ucb);
551 input_unregister_device(ucb->ts_idev);
552 dev_set_drvdata(dev, NULL);
557 static struct device_driver ucb1400_ts_driver = {
558 .name = "ucb1400_ts",
559 .owner = THIS_MODULE,
560 .bus = &ac97_bus_type,
561 .probe = ucb1400_ts_probe,
562 .remove = ucb1400_ts_remove,
563 .resume = ucb1400_ts_resume,
566 static int __init ucb1400_ts_init(void)
568 return driver_register(&ucb1400_ts_driver);
571 static void __exit ucb1400_ts_exit(void)
573 driver_unregister(&ucb1400_ts_driver);
576 module_param(adcsync, bool, 0444);
577 MODULE_PARM_DESC(adcsync, "Synchronize touch readings with ADCSYNC pin.");
579 module_param(ts_delay, int, 0444);
580 MODULE_PARM_DESC(ts_delay, "Delay between panel setup and position read. Default = 55us.");
582 module_param(ts_delay_pressure, int, 0444);
583 MODULE_PARM_DESC(ts_delay_pressure,
584 "delay between panel setup and pressure read. Default = 0us.");
586 module_init(ucb1400_ts_init);
587 module_exit(ucb1400_ts_exit);
589 MODULE_DESCRIPTION("Philips UCB1400 touchscreen driver");
590 MODULE_LICENSE("GPL");