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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Philips UCB1400 touchscreen driver
4 *
5 * Author: Nicolas Pitre
6 * Created: September 25, 2006
7 * Copyright: MontaVista Software, Inc.
8 *
9 * Spliting done by: Marek Vasut <marek.vasut@gmail.com>
10 * If something doesn't work and it worked before spliting, e-mail me,
11 * dont bother Nicolas please ;-)
12 *
13 * This code is heavily based on ucb1x00-*.c copyrighted by Russell King
14 * covering the UCB1100, UCB1200 and UCB1300.. Support for the UCB1400 has
15 * been made separate from ucb1x00-core/ucb1x00-ts on Russell's request.
16 */
17
18#include <linux/module.h>
19#include <linux/delay.h>
20#include <linux/sched.h>
21#include <linux/wait.h>
22#include <linux/input.h>
23#include <linux/device.h>
24#include <linux/interrupt.h>
25#include <linux/ucb1400.h>
26
27#define UCB1400_TS_POLL_PERIOD 10 /* ms */
28
29static bool adcsync;
30static int ts_delay = 55; /* us */
31static int ts_delay_pressure; /* us */
32
33/* Switch to interrupt mode. */
34static void ucb1400_ts_mode_int(struct ucb1400_ts *ucb)
35{
36 ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
37 UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW |
38 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |
39 UCB_TS_CR_MODE_INT);
40}
41
42/*
43 * Switch to pressure mode, and read pressure. We don't need to wait
44 * here, since both plates are being driven.
45 */
46static unsigned int ucb1400_ts_read_pressure(struct ucb1400_ts *ucb)
47{
48 ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
49 UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW |
50 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |
51 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
52
53 udelay(ts_delay_pressure);
54
55 return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPY, adcsync);
56}
57
58/*
59 * Switch to X position mode and measure Y plate. We switch the plate
60 * configuration in pressure mode, then switch to position mode. This
61 * gives a faster response time. Even so, we need to wait about 55us
62 * for things to stabilise.
63 */
64static unsigned int ucb1400_ts_read_xpos(struct ucb1400_ts *ucb)
65{
66 ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
67 UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
68 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
69 ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
70 UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
71 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
72 ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
73 UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
74 UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);
75
76 udelay(ts_delay);
77
78 return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPY, adcsync);
79}
80
81/*
82 * Switch to Y position mode and measure X plate. We switch the plate
83 * configuration in pressure mode, then switch to position mode. This
84 * gives a faster response time. Even so, we need to wait about 55us
85 * for things to stabilise.
86 */
87static int ucb1400_ts_read_ypos(struct ucb1400_ts *ucb)
88{
89 ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
90 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
91 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
92 ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
93 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
94 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
95 ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
96 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
97 UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);
98
99 udelay(ts_delay);
100
101 return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPX, adcsync);
102}
103
104/*
105 * Switch to X plate resistance mode. Set MX to ground, PX to
106 * supply. Measure current.
107 */
108static unsigned int ucb1400_ts_read_xres(struct ucb1400_ts *ucb)
109{
110 ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
111 UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
112 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
113 return ucb1400_adc_read(ucb->ac97, 0, adcsync);
114}
115
116/*
117 * Switch to Y plate resistance mode. Set MY to ground, PY to
118 * supply. Measure current.
119 */
120static unsigned int ucb1400_ts_read_yres(struct ucb1400_ts *ucb)
121{
122 ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
123 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
124 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
125 return ucb1400_adc_read(ucb->ac97, 0, adcsync);
126}
127
128static int ucb1400_ts_pen_up(struct ucb1400_ts *ucb)
129{
130 unsigned short val = ucb1400_reg_read(ucb->ac97, UCB_TS_CR);
131
132 return val & (UCB_TS_CR_TSPX_LOW | UCB_TS_CR_TSMX_LOW);
133}
134
135static void ucb1400_ts_irq_enable(struct ucb1400_ts *ucb)
136{
137 ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, UCB_IE_TSPX);
138 ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);
139 ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, UCB_IE_TSPX);
140}
141
142static void ucb1400_ts_irq_disable(struct ucb1400_ts *ucb)
143{
144 ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, 0);
145}
146
147static void ucb1400_ts_report_event(struct input_dev *idev, u16 pressure, u16 x, u16 y)
148{
149 input_report_abs(idev, ABS_X, x);
150 input_report_abs(idev, ABS_Y, y);
151 input_report_abs(idev, ABS_PRESSURE, pressure);
152 input_report_key(idev, BTN_TOUCH, 1);
153 input_sync(idev);
154}
155
156static void ucb1400_ts_event_release(struct input_dev *idev)
157{
158 input_report_abs(idev, ABS_PRESSURE, 0);
159 input_report_key(idev, BTN_TOUCH, 0);
160 input_sync(idev);
161}
162
163static void ucb1400_clear_pending_irq(struct ucb1400_ts *ucb)
164{
165 unsigned int isr;
166
167 isr = ucb1400_reg_read(ucb->ac97, UCB_IE_STATUS);
168 ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, isr);
169 ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);
170
171 if (isr & UCB_IE_TSPX)
172 ucb1400_ts_irq_disable(ucb);
173 else
174 dev_dbg(&ucb->ts_idev->dev,
175 "ucb1400: unexpected IE_STATUS = %#x\n", isr);
176}
177
178/*
179 * A restriction with interrupts exists when using the ucb1400, as
180 * the codec read/write routines may sleep while waiting for codec
181 * access completion and uses semaphores for access control to the
182 * AC97 bus. Therefore the driver is forced to use threaded interrupt
183 * handler.
184 */
185static irqreturn_t ucb1400_irq(int irqnr, void *devid)
186{
187 struct ucb1400_ts *ucb = devid;
188 unsigned int x, y, p;
189
190 if (unlikely(irqnr != ucb->irq))
191 return IRQ_NONE;
192
193 ucb1400_clear_pending_irq(ucb);
194
195 /* Start with a small delay before checking pendown state */
196 msleep(UCB1400_TS_POLL_PERIOD);
197
198 while (!ucb->stopped && !ucb1400_ts_pen_up(ucb)) {
199 ucb1400_adc_enable(ucb->ac97);
200 x = ucb1400_ts_read_xpos(ucb);
201 y = ucb1400_ts_read_ypos(ucb);
202 p = ucb1400_ts_read_pressure(ucb);
203 ucb1400_adc_disable(ucb->ac97);
204
205 ucb1400_ts_report_event(ucb->ts_idev, p, x, y);
206
207 wait_event_timeout(ucb->ts_wait, ucb->stopped,
208 msecs_to_jiffies(UCB1400_TS_POLL_PERIOD));
209 }
210
211 ucb1400_ts_event_release(ucb->ts_idev);
212
213 if (!ucb->stopped) {
214 /* Switch back to interrupt mode. */
215 ucb1400_ts_mode_int(ucb);
216 ucb1400_ts_irq_enable(ucb);
217 }
218
219 return IRQ_HANDLED;
220}
221
222static void ucb1400_ts_stop(struct ucb1400_ts *ucb)
223{
224 /* Signal IRQ thread to stop polling and disable the handler. */
225 ucb->stopped = true;
226 mb();
227 wake_up(&ucb->ts_wait);
228 disable_irq(ucb->irq);
229
230 ucb1400_ts_irq_disable(ucb);
231 ucb1400_reg_write(ucb->ac97, UCB_TS_CR, 0);
232}
233
234/* Must be called with ts->lock held */
235static void ucb1400_ts_start(struct ucb1400_ts *ucb)
236{
237 /* Tell IRQ thread that it may poll the device. */
238 ucb->stopped = false;
239 mb();
240
241 ucb1400_ts_mode_int(ucb);
242 ucb1400_ts_irq_enable(ucb);
243
244 enable_irq(ucb->irq);
245}
246
247static int ucb1400_ts_open(struct input_dev *idev)
248{
249 struct ucb1400_ts *ucb = input_get_drvdata(idev);
250
251 ucb1400_ts_start(ucb);
252
253 return 0;
254}
255
256static void ucb1400_ts_close(struct input_dev *idev)
257{
258 struct ucb1400_ts *ucb = input_get_drvdata(idev);
259
260 ucb1400_ts_stop(ucb);
261}
262
263#ifndef NO_IRQ
264#define NO_IRQ 0
265#endif
266
267/*
268 * Try to probe our interrupt, rather than relying on lots of
269 * hard-coded machine dependencies.
270 */
271static int ucb1400_ts_detect_irq(struct ucb1400_ts *ucb,
272 struct platform_device *pdev)
273{
274 unsigned long mask, timeout;
275
276 mask = probe_irq_on();
277
278 /* Enable the ADC interrupt. */
279 ucb1400_reg_write(ucb->ac97, UCB_IE_RIS, UCB_IE_ADC);
280 ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, UCB_IE_ADC);
281 ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0xffff);
282 ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);
283
284 /* Cause an ADC interrupt. */
285 ucb1400_reg_write(ucb->ac97, UCB_ADC_CR, UCB_ADC_ENA);
286 ucb1400_reg_write(ucb->ac97, UCB_ADC_CR, UCB_ADC_ENA | UCB_ADC_START);
287
288 /* Wait for the conversion to complete. */
289 timeout = jiffies + HZ/2;
290 while (!(ucb1400_reg_read(ucb->ac97, UCB_ADC_DATA) &
291 UCB_ADC_DAT_VALID)) {
292 cpu_relax();
293 if (time_after(jiffies, timeout)) {
294 dev_err(&pdev->dev, "timed out in IRQ probe\n");
295 probe_irq_off(mask);
296 return -ENODEV;
297 }
298 }
299 ucb1400_reg_write(ucb->ac97, UCB_ADC_CR, 0);
300
301 /* Disable and clear interrupt. */
302 ucb1400_reg_write(ucb->ac97, UCB_IE_RIS, 0);
303 ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, 0);
304 ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0xffff);
305 ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);
306
307 /* Read triggered interrupt. */
308 ucb->irq = probe_irq_off(mask);
309 if (ucb->irq < 0 || ucb->irq == NO_IRQ)
310 return -ENODEV;
311
312 return 0;
313}
314
315static int ucb1400_ts_probe(struct platform_device *pdev)
316{
317 struct ucb1400_ts *ucb = dev_get_platdata(&pdev->dev);
318 int error, x_res, y_res;
319 u16 fcsr;
320
321 ucb->ts_idev = input_allocate_device();
322 if (!ucb->ts_idev) {
323 error = -ENOMEM;
324 goto err;
325 }
326
327 /* Only in case the IRQ line wasn't supplied, try detecting it */
328 if (ucb->irq < 0) {
329 error = ucb1400_ts_detect_irq(ucb, pdev);
330 if (error) {
331 dev_err(&pdev->dev, "IRQ probe failed\n");
332 goto err_free_devs;
333 }
334 }
335 dev_dbg(&pdev->dev, "found IRQ %d\n", ucb->irq);
336
337 init_waitqueue_head(&ucb->ts_wait);
338
339 input_set_drvdata(ucb->ts_idev, ucb);
340
341 ucb->ts_idev->dev.parent = &pdev->dev;
342 ucb->ts_idev->name = "UCB1400 touchscreen interface";
343 ucb->ts_idev->id.vendor = ucb1400_reg_read(ucb->ac97,
344 AC97_VENDOR_ID1);
345 ucb->ts_idev->id.product = ucb->id;
346 ucb->ts_idev->open = ucb1400_ts_open;
347 ucb->ts_idev->close = ucb1400_ts_close;
348 ucb->ts_idev->evbit[0] = BIT_MASK(EV_ABS) | BIT_MASK(EV_KEY);
349 ucb->ts_idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
350
351 /*
352 * Enable ADC filter to prevent horrible jitter on Colibri.
353 * This also further reduces jitter on boards where ADCSYNC
354 * pin is connected.
355 */
356 fcsr = ucb1400_reg_read(ucb->ac97, UCB_FCSR);
357 ucb1400_reg_write(ucb->ac97, UCB_FCSR, fcsr | UCB_FCSR_AVE);
358
359 ucb1400_adc_enable(ucb->ac97);
360 x_res = ucb1400_ts_read_xres(ucb);
361 y_res = ucb1400_ts_read_yres(ucb);
362 ucb1400_adc_disable(ucb->ac97);
363 dev_dbg(&pdev->dev, "x/y = %d/%d\n", x_res, y_res);
364
365 input_set_abs_params(ucb->ts_idev, ABS_X, 0, x_res, 0, 0);
366 input_set_abs_params(ucb->ts_idev, ABS_Y, 0, y_res, 0, 0);
367 input_set_abs_params(ucb->ts_idev, ABS_PRESSURE, 0, 0, 0, 0);
368
369 ucb1400_ts_stop(ucb);
370
371 error = request_threaded_irq(ucb->irq, NULL, ucb1400_irq,
372 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
373 "UCB1400", ucb);
374 if (error) {
375 dev_err(&pdev->dev,
376 "unable to grab irq%d: %d\n", ucb->irq, error);
377 goto err_free_devs;
378 }
379
380 error = input_register_device(ucb->ts_idev);
381 if (error)
382 goto err_free_irq;
383
384 return 0;
385
386err_free_irq:
387 free_irq(ucb->irq, ucb);
388err_free_devs:
389 input_free_device(ucb->ts_idev);
390err:
391 return error;
392}
393
394static int ucb1400_ts_remove(struct platform_device *pdev)
395{
396 struct ucb1400_ts *ucb = dev_get_platdata(&pdev->dev);
397
398 free_irq(ucb->irq, ucb);
399 input_unregister_device(ucb->ts_idev);
400
401 return 0;
402}
403
404static int __maybe_unused ucb1400_ts_suspend(struct device *dev)
405{
406 struct ucb1400_ts *ucb = dev_get_platdata(dev);
407 struct input_dev *idev = ucb->ts_idev;
408
409 mutex_lock(&idev->mutex);
410
411 if (input_device_enabled(idev))
412 ucb1400_ts_stop(ucb);
413
414 mutex_unlock(&idev->mutex);
415 return 0;
416}
417
418static int __maybe_unused ucb1400_ts_resume(struct device *dev)
419{
420 struct ucb1400_ts *ucb = dev_get_platdata(dev);
421 struct input_dev *idev = ucb->ts_idev;
422
423 mutex_lock(&idev->mutex);
424
425 if (input_device_enabled(idev))
426 ucb1400_ts_start(ucb);
427
428 mutex_unlock(&idev->mutex);
429 return 0;
430}
431
432static SIMPLE_DEV_PM_OPS(ucb1400_ts_pm_ops,
433 ucb1400_ts_suspend, ucb1400_ts_resume);
434
435static struct platform_driver ucb1400_ts_driver = {
436 .probe = ucb1400_ts_probe,
437 .remove = ucb1400_ts_remove,
438 .driver = {
439 .name = "ucb1400_ts",
440 .pm = &ucb1400_ts_pm_ops,
441 },
442};
443module_platform_driver(ucb1400_ts_driver);
444
445module_param(adcsync, bool, 0444);
446MODULE_PARM_DESC(adcsync, "Synchronize touch readings with ADCSYNC pin.");
447
448module_param(ts_delay, int, 0444);
449MODULE_PARM_DESC(ts_delay, "Delay between panel setup and"
450 " position read. Default = 55us.");
451
452module_param(ts_delay_pressure, int, 0444);
453MODULE_PARM_DESC(ts_delay_pressure,
454 "delay between panel setup and pressure read."
455 " Default = 0us.");
456
457MODULE_DESCRIPTION("Philips UCB1400 touchscreen driver");
458MODULE_LICENSE("GPL");