1 /*
2 * Philips UCB1400 touchscreen driver
3 *
4 * Author: Nicolas Pitre
5 * Created: September 25, 2006
6 * Copyright: MontaVista Software, Inc.
7 *
8 * Spliting done by: Marek Vasut <marek.vasut@gmail.com>
9 * If something doesn't work and it worked before spliting, e-mail me,
10 * dont bother Nicolas please ;-)
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License version 2 as
14 * published by the Free Software Foundation.
15 *
16 * This code is heavily based on ucb1x00-*.c copyrighted by Russell King
17 * covering the UCB1100, UCB1200 and UCB1300.. Support for the UCB1400 has
18 * been made separate from ucb1x00-core/ucb1x00-ts on Russell's request.
19 */
20
21 #include <linux/module.h>
22 #include <linux/init.h>
23 #include <linux/delay.h>
24 #include <linux/sched.h>
25 #include <linux/wait.h>
26 #include <linux/input.h>
27 #include <linux/device.h>
28 #include <linux/interrupt.h>
29 #include <linux/ucb1400.h>
30
31 #define UCB1400_TS_POLL_PERIOD 10 /* ms */
32
33 static bool adcsync;
34 static int ts_delay = 55; /* us */
35 static int ts_delay_pressure; /* us */
36
37 /* Switch to interrupt mode. */
ucb1400_ts_mode_int(struct ucb1400_ts * ucb)38 static void ucb1400_ts_mode_int(struct ucb1400_ts *ucb)
39 {
40 ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
41 UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW |
42 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |
43 UCB_TS_CR_MODE_INT);
44 }
45
46 /*
47 * Switch to pressure mode, and read pressure. We don't need to wait
48 * here, since both plates are being driven.
49 */
ucb1400_ts_read_pressure(struct ucb1400_ts * ucb)50 static unsigned int ucb1400_ts_read_pressure(struct ucb1400_ts *ucb)
51 {
52 ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
53 UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW |
54 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |
55 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
56
57 udelay(ts_delay_pressure);
58
59 return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPY, adcsync);
60 }
61
62 /*
63 * Switch to X position mode and measure Y plate. We switch the plate
64 * configuration in pressure mode, then switch to position mode. This
65 * gives a faster response time. Even so, we need to wait about 55us
66 * for things to stabilise.
67 */
ucb1400_ts_read_xpos(struct ucb1400_ts * ucb)68 static unsigned int ucb1400_ts_read_xpos(struct ucb1400_ts *ucb)
69 {
70 ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
71 UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
72 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
73 ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
74 UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
75 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
76 ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
77 UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
78 UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);
79
80 udelay(ts_delay);
81
82 return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPY, adcsync);
83 }
84
85 /*
86 * Switch to Y position mode and measure X plate. We switch the plate
87 * configuration in pressure mode, then switch to position mode. This
88 * gives a faster response time. Even so, we need to wait about 55us
89 * for things to stabilise.
90 */
ucb1400_ts_read_ypos(struct ucb1400_ts * ucb)91 static int ucb1400_ts_read_ypos(struct ucb1400_ts *ucb)
92 {
93 ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
94 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
95 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
96 ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
97 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
98 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
99 ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
100 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
101 UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);
102
103 udelay(ts_delay);
104
105 return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPX, adcsync);
106 }
107
108 /*
109 * Switch to X plate resistance mode. Set MX to ground, PX to
110 * supply. Measure current.
111 */
ucb1400_ts_read_xres(struct ucb1400_ts * ucb)112 static unsigned int ucb1400_ts_read_xres(struct ucb1400_ts *ucb)
113 {
114 ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
115 UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
116 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
117 return ucb1400_adc_read(ucb->ac97, 0, adcsync);
118 }
119
120 /*
121 * Switch to Y plate resistance mode. Set MY to ground, PY to
122 * supply. Measure current.
123 */
ucb1400_ts_read_yres(struct ucb1400_ts * ucb)124 static unsigned int ucb1400_ts_read_yres(struct ucb1400_ts *ucb)
125 {
126 ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
127 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
128 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
129 return ucb1400_adc_read(ucb->ac97, 0, adcsync);
130 }
131
ucb1400_ts_pen_up(struct ucb1400_ts * ucb)132 static int ucb1400_ts_pen_up(struct ucb1400_ts *ucb)
133 {
134 unsigned short val = ucb1400_reg_read(ucb->ac97, UCB_TS_CR);
135
136 return val & (UCB_TS_CR_TSPX_LOW | UCB_TS_CR_TSMX_LOW);
137 }
138
ucb1400_ts_irq_enable(struct ucb1400_ts * ucb)139 static void ucb1400_ts_irq_enable(struct ucb1400_ts *ucb)
140 {
141 ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, UCB_IE_TSPX);
142 ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);
143 ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, UCB_IE_TSPX);
144 }
145
ucb1400_ts_irq_disable(struct ucb1400_ts * ucb)146 static void ucb1400_ts_irq_disable(struct ucb1400_ts *ucb)
147 {
148 ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, 0);
149 }
150
ucb1400_ts_report_event(struct input_dev * idev,u16 pressure,u16 x,u16 y)151 static void ucb1400_ts_report_event(struct input_dev *idev, u16 pressure, u16 x, u16 y)
152 {
153 input_report_abs(idev, ABS_X, x);
154 input_report_abs(idev, ABS_Y, y);
155 input_report_abs(idev, ABS_PRESSURE, pressure);
156 input_report_key(idev, BTN_TOUCH, 1);
157 input_sync(idev);
158 }
159
ucb1400_ts_event_release(struct input_dev * idev)160 static void ucb1400_ts_event_release(struct input_dev *idev)
161 {
162 input_report_abs(idev, ABS_PRESSURE, 0);
163 input_report_key(idev, BTN_TOUCH, 0);
164 input_sync(idev);
165 }
166
ucb1400_clear_pending_irq(struct ucb1400_ts * ucb)167 static void ucb1400_clear_pending_irq(struct ucb1400_ts *ucb)
168 {
169 unsigned int isr;
170
171 isr = ucb1400_reg_read(ucb->ac97, UCB_IE_STATUS);
172 ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, isr);
173 ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);
174
175 if (isr & UCB_IE_TSPX)
176 ucb1400_ts_irq_disable(ucb);
177 else
178 dev_dbg(&ucb->ts_idev->dev,
179 "ucb1400: unexpected IE_STATUS = %#x\n", isr);
180 }
181
182 /*
183 * A restriction with interrupts exists when using the ucb1400, as
184 * the codec read/write routines may sleep while waiting for codec
185 * access completion and uses semaphores for access control to the
186 * AC97 bus. Therefore the driver is forced to use threaded interrupt
187 * handler.
188 */
ucb1400_irq(int irqnr,void * devid)189 static irqreturn_t ucb1400_irq(int irqnr, void *devid)
190 {
191 struct ucb1400_ts *ucb = devid;
192 unsigned int x, y, p;
193 bool penup;
194
195 if (unlikely(irqnr != ucb->irq))
196 return IRQ_NONE;
197
198 ucb1400_clear_pending_irq(ucb);
199
200 /* Start with a small delay before checking pendown state */
201 msleep(UCB1400_TS_POLL_PERIOD);
202
203 while (!ucb->stopped && !(penup = ucb1400_ts_pen_up(ucb))) {
204
205 ucb1400_adc_enable(ucb->ac97);
206 x = ucb1400_ts_read_xpos(ucb);
207 y = ucb1400_ts_read_ypos(ucb);
208 p = ucb1400_ts_read_pressure(ucb);
209 ucb1400_adc_disable(ucb->ac97);
210
211 ucb1400_ts_report_event(ucb->ts_idev, p, x, y);
212
213 wait_event_timeout(ucb->ts_wait, ucb->stopped,
214 msecs_to_jiffies(UCB1400_TS_POLL_PERIOD));
215 }
216
217 ucb1400_ts_event_release(ucb->ts_idev);
218
219 if (!ucb->stopped) {
220 /* Switch back to interrupt mode. */
221 ucb1400_ts_mode_int(ucb);
222 ucb1400_ts_irq_enable(ucb);
223 }
224
225 return IRQ_HANDLED;
226 }
227
ucb1400_ts_stop(struct ucb1400_ts * ucb)228 static void ucb1400_ts_stop(struct ucb1400_ts *ucb)
229 {
230 /* Signal IRQ thread to stop polling and disable the handler. */
231 ucb->stopped = true;
232 mb();
233 wake_up(&ucb->ts_wait);
234 disable_irq(ucb->irq);
235
236 ucb1400_ts_irq_disable(ucb);
237 ucb1400_reg_write(ucb->ac97, UCB_TS_CR, 0);
238 }
239
240 /* Must be called with ts->lock held */
ucb1400_ts_start(struct ucb1400_ts * ucb)241 static void ucb1400_ts_start(struct ucb1400_ts *ucb)
242 {
243 /* Tell IRQ thread that it may poll the device. */
244 ucb->stopped = false;
245 mb();
246
247 ucb1400_ts_mode_int(ucb);
248 ucb1400_ts_irq_enable(ucb);
249
250 enable_irq(ucb->irq);
251 }
252
ucb1400_ts_open(struct input_dev * idev)253 static int ucb1400_ts_open(struct input_dev *idev)
254 {
255 struct ucb1400_ts *ucb = input_get_drvdata(idev);
256
257 ucb1400_ts_start(ucb);
258
259 return 0;
260 }
261
ucb1400_ts_close(struct input_dev * idev)262 static void ucb1400_ts_close(struct input_dev *idev)
263 {
264 struct ucb1400_ts *ucb = input_get_drvdata(idev);
265
266 ucb1400_ts_stop(ucb);
267 }
268
269 #ifndef NO_IRQ
270 #define NO_IRQ 0
271 #endif
272
273 /*
274 * Try to probe our interrupt, rather than relying on lots of
275 * hard-coded machine dependencies.
276 */
ucb1400_ts_detect_irq(struct ucb1400_ts * ucb,struct platform_device * pdev)277 static int ucb1400_ts_detect_irq(struct ucb1400_ts *ucb,
278 struct platform_device *pdev)
279 {
280 unsigned long mask, timeout;
281
282 mask = probe_irq_on();
283
284 /* Enable the ADC interrupt. */
285 ucb1400_reg_write(ucb->ac97, UCB_IE_RIS, UCB_IE_ADC);
286 ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, UCB_IE_ADC);
287 ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0xffff);
288 ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);
289
290 /* Cause an ADC interrupt. */
291 ucb1400_reg_write(ucb->ac97, UCB_ADC_CR, UCB_ADC_ENA);
292 ucb1400_reg_write(ucb->ac97, UCB_ADC_CR, UCB_ADC_ENA | UCB_ADC_START);
293
294 /* Wait for the conversion to complete. */
295 timeout = jiffies + HZ/2;
296 while (!(ucb1400_reg_read(ucb->ac97, UCB_ADC_DATA) &
297 UCB_ADC_DAT_VALID)) {
298 cpu_relax();
299 if (time_after(jiffies, timeout)) {
300 dev_err(&pdev->dev, "timed out in IRQ probe\n");
301 probe_irq_off(mask);
302 return -ENODEV;
303 }
304 }
305 ucb1400_reg_write(ucb->ac97, UCB_ADC_CR, 0);
306
307 /* Disable and clear interrupt. */
308 ucb1400_reg_write(ucb->ac97, UCB_IE_RIS, 0);
309 ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, 0);
310 ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0xffff);
311 ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);
312
313 /* Read triggered interrupt. */
314 ucb->irq = probe_irq_off(mask);
315 if (ucb->irq < 0 || ucb->irq == NO_IRQ)
316 return -ENODEV;
317
318 return 0;
319 }
320
ucb1400_ts_probe(struct platform_device * pdev)321 static int ucb1400_ts_probe(struct platform_device *pdev)
322 {
323 struct ucb1400_ts *ucb = pdev->dev.platform_data;
324 int error, x_res, y_res;
325 u16 fcsr;
326
327 ucb->ts_idev = input_allocate_device();
328 if (!ucb->ts_idev) {
329 error = -ENOMEM;
330 goto err;
331 }
332
333 /* Only in case the IRQ line wasn't supplied, try detecting it */
334 if (ucb->irq < 0) {
335 error = ucb1400_ts_detect_irq(ucb, pdev);
336 if (error) {
337 dev_err(&pdev->dev, "IRQ probe failed\n");
338 goto err_free_devs;
339 }
340 }
341 dev_dbg(&pdev->dev, "found IRQ %d\n", ucb->irq);
342
343 init_waitqueue_head(&ucb->ts_wait);
344
345 input_set_drvdata(ucb->ts_idev, ucb);
346
347 ucb->ts_idev->dev.parent = &pdev->dev;
348 ucb->ts_idev->name = "UCB1400 touchscreen interface";
349 ucb->ts_idev->id.vendor = ucb1400_reg_read(ucb->ac97,
350 AC97_VENDOR_ID1);
351 ucb->ts_idev->id.product = ucb->id;
352 ucb->ts_idev->open = ucb1400_ts_open;
353 ucb->ts_idev->close = ucb1400_ts_close;
354 ucb->ts_idev->evbit[0] = BIT_MASK(EV_ABS) | BIT_MASK(EV_KEY);
355 ucb->ts_idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
356
357 /*
358 * Enable ADC filter to prevent horrible jitter on Colibri.
359 * This also further reduces jitter on boards where ADCSYNC
360 * pin is connected.
361 */
362 fcsr = ucb1400_reg_read(ucb->ac97, UCB_FCSR);
363 ucb1400_reg_write(ucb->ac97, UCB_FCSR, fcsr | UCB_FCSR_AVE);
364
365 ucb1400_adc_enable(ucb->ac97);
366 x_res = ucb1400_ts_read_xres(ucb);
367 y_res = ucb1400_ts_read_yres(ucb);
368 ucb1400_adc_disable(ucb->ac97);
369 dev_dbg(&pdev->dev, "x/y = %d/%d\n", x_res, y_res);
370
371 input_set_abs_params(ucb->ts_idev, ABS_X, 0, x_res, 0, 0);
372 input_set_abs_params(ucb->ts_idev, ABS_Y, 0, y_res, 0, 0);
373 input_set_abs_params(ucb->ts_idev, ABS_PRESSURE, 0, 0, 0, 0);
374
375 ucb1400_ts_stop(ucb);
376
377 error = request_threaded_irq(ucb->irq, NULL, ucb1400_irq,
378 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
379 "UCB1400", ucb);
380 if (error) {
381 dev_err(&pdev->dev,
382 "unable to grab irq%d: %d\n", ucb->irq, error);
383 goto err_free_devs;
384 }
385
386 error = input_register_device(ucb->ts_idev);
387 if (error)
388 goto err_free_irq;
389
390 return 0;
391
392 err_free_irq:
393 free_irq(ucb->irq, ucb);
394 err_free_devs:
395 input_free_device(ucb->ts_idev);
396 err:
397 return error;
398 }
399
ucb1400_ts_remove(struct platform_device * pdev)400 static int ucb1400_ts_remove(struct platform_device *pdev)
401 {
402 struct ucb1400_ts *ucb = pdev->dev.platform_data;
403
404 free_irq(ucb->irq, ucb);
405 input_unregister_device(ucb->ts_idev);
406
407 return 0;
408 }
409
410 #ifdef CONFIG_PM_SLEEP
ucb1400_ts_suspend(struct device * dev)411 static int ucb1400_ts_suspend(struct device *dev)
412 {
413 struct ucb1400_ts *ucb = dev->platform_data;
414 struct input_dev *idev = ucb->ts_idev;
415
416 mutex_lock(&idev->mutex);
417
418 if (idev->users)
419 ucb1400_ts_start(ucb);
420
421 mutex_unlock(&idev->mutex);
422 return 0;
423 }
424
ucb1400_ts_resume(struct device * dev)425 static int ucb1400_ts_resume(struct device *dev)
426 {
427 struct ucb1400_ts *ucb = dev->platform_data;
428 struct input_dev *idev = ucb->ts_idev;
429
430 mutex_lock(&idev->mutex);
431
432 if (idev->users)
433 ucb1400_ts_stop(ucb);
434
435 mutex_unlock(&idev->mutex);
436 return 0;
437 }
438 #endif
439
440 static SIMPLE_DEV_PM_OPS(ucb1400_ts_pm_ops,
441 ucb1400_ts_suspend, ucb1400_ts_resume);
442
443 static struct platform_driver ucb1400_ts_driver = {
444 .probe = ucb1400_ts_probe,
445 .remove = ucb1400_ts_remove,
446 .driver = {
447 .name = "ucb1400_ts",
448 .owner = THIS_MODULE,
449 .pm = &ucb1400_ts_pm_ops,
450 },
451 };
452 module_platform_driver(ucb1400_ts_driver);
453
454 module_param(adcsync, bool, 0444);
455 MODULE_PARM_DESC(adcsync, "Synchronize touch readings with ADCSYNC pin.");
456
457 module_param(ts_delay, int, 0444);
458 MODULE_PARM_DESC(ts_delay, "Delay between panel setup and"
459 " position read. Default = 55us.");
460
461 module_param(ts_delay_pressure, int, 0444);
462 MODULE_PARM_DESC(ts_delay_pressure,
463 "delay between panel setup and pressure read."
464 " Default = 0us.");
465
466 MODULE_DESCRIPTION("Philips UCB1400 touchscreen driver");
467 MODULE_LICENSE("GPL");
468