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Linux/drivers/input/touchscreen/ucb1400_ts.c

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

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