Input: add support for WM97xx familty touchscreens
[linux-2.6.git] / drivers / input / touchscreen / wm97xx-core.c
1 /*
2  * wm97xx-core.c  --  Touch screen driver core for Wolfson WM9705, WM9712
3  *                    and WM9713 AC97 Codecs.
4  *
5  * Copyright 2003, 2004, 2005, 2006, 2007, 2008 Wolfson Microelectronics PLC.
6  * Author: Liam Girdwood
7  *         liam.girdwood@wolfsonmicro.com or linux@wolfsonmicro.com
8  * Parts Copyright : Ian Molton <spyro@f2s.com>
9  *                   Andrew Zabolotny <zap@homelink.ru>
10  *                   Russell King <rmk@arm.linux.org.uk>
11  *
12  *  This program is free software; you can redistribute  it and/or modify it
13  *  under  the terms of  the GNU General  Public License as published by the
14  *  Free Software Foundation;  either version 2 of the  License, or (at your
15  *  option) any later version.
16  *
17  * Notes:
18  *
19  *  Features:
20  *       - supports WM9705, WM9712, WM9713
21  *       - polling mode
22  *       - continuous mode (arch-dependent)
23  *       - adjustable rpu/dpp settings
24  *       - adjustable pressure current
25  *       - adjustable sample settle delay
26  *       - 4 and 5 wire touchscreens (5 wire is WM9712 only)
27  *       - pen down detection
28  *       - battery monitor
29  *       - sample AUX adcs
30  *       - power management
31  *       - codec GPIO
32  *       - codec event notification
33  * Todo
34  *       - Support for async sampling control for noisy LCDs.
35  *
36  */
37
38 #include <linux/module.h>
39 #include <linux/moduleparam.h>
40 #include <linux/version.h>
41 #include <linux/kernel.h>
42 #include <linux/init.h>
43 #include <linux/delay.h>
44 #include <linux/string.h>
45 #include <linux/proc_fs.h>
46 #include <linux/pm.h>
47 #include <linux/interrupt.h>
48 #include <linux/bitops.h>
49 #include <linux/workqueue.h>
50 #include <linux/wm97xx.h>
51 #include <linux/uaccess.h>
52 #include <linux/io.h>
53
54 #define TS_NAME                 "wm97xx"
55 #define WM_CORE_VERSION         "1.00"
56 #define DEFAULT_PRESSURE        0xb0c0
57
58
59 /*
60  * Touchscreen absolute values
61  *
62  * These parameters are used to help the input layer discard out of
63  * range readings and reduce jitter etc.
64  *
65  *   o min, max:- indicate the min and max values your touch screen returns
66  *   o fuzz:- use a higher number to reduce jitter
67  *
68  * The default values correspond to Mainstone II in QVGA mode
69  *
70  * Please read
71  * Documentation/input/input-programming.txt for more details.
72  */
73
74 static int abs_x[3] = {350, 3900, 5};
75 module_param_array(abs_x, int, NULL, 0);
76 MODULE_PARM_DESC(abs_x, "Touchscreen absolute X min, max, fuzz");
77
78 static int abs_y[3] = {320, 3750, 40};
79 module_param_array(abs_y, int, NULL, 0);
80 MODULE_PARM_DESC(abs_y, "Touchscreen absolute Y min, max, fuzz");
81
82 static int abs_p[3] = {0, 150, 4};
83 module_param_array(abs_p, int, NULL, 0);
84 MODULE_PARM_DESC(abs_p, "Touchscreen absolute Pressure min, max, fuzz");
85
86 /*
87  * wm97xx IO access, all IO locking done by AC97 layer
88  */
89 int wm97xx_reg_read(struct wm97xx *wm, u16 reg)
90 {
91         if (wm->ac97)
92                 return wm->ac97->bus->ops->read(wm->ac97, reg);
93         else
94                 return -1;
95 }
96 EXPORT_SYMBOL_GPL(wm97xx_reg_read);
97
98 void wm97xx_reg_write(struct wm97xx *wm, u16 reg, u16 val)
99 {
100         /* cache digitiser registers */
101         if (reg >= AC97_WM9713_DIG1 && reg <= AC97_WM9713_DIG3)
102                 wm->dig[(reg - AC97_WM9713_DIG1) >> 1] = val;
103
104         /* cache gpio regs */
105         if (reg >= AC97_GPIO_CFG && reg <= AC97_MISC_AFE)
106                 wm->gpio[(reg - AC97_GPIO_CFG) >> 1] = val;
107
108         /* wm9713 irq reg */
109         if (reg == 0x5a)
110                 wm->misc = val;
111
112         if (wm->ac97)
113                 wm->ac97->bus->ops->write(wm->ac97, reg, val);
114 }
115 EXPORT_SYMBOL_GPL(wm97xx_reg_write);
116
117 /**
118  * wm97xx_read_aux_adc - Read the aux adc.
119  * @wm: wm97xx device.
120  * @adcsel: codec ADC to be read
121  *
122  * Reads the selected AUX ADC.
123  */
124
125 int wm97xx_read_aux_adc(struct wm97xx *wm, u16 adcsel)
126 {
127         int power_adc = 0, auxval;
128         u16 power = 0;
129
130         /* get codec */
131         mutex_lock(&wm->codec_mutex);
132
133         /* When the touchscreen is not in use, we may have to power up
134          * the AUX ADC before we can use sample the AUX inputs->
135          */
136         if (wm->id == WM9713_ID2 &&
137             (power = wm97xx_reg_read(wm, AC97_EXTENDED_MID)) & 0x8000) {
138                 power_adc = 1;
139                 wm97xx_reg_write(wm, AC97_EXTENDED_MID, power & 0x7fff);
140         }
141
142         /* Prepare the codec for AUX reading */
143         wm->codec->aux_prepare(wm);
144
145         /* Turn polling mode on to read AUX ADC */
146         wm->pen_probably_down = 1;
147         wm->codec->poll_sample(wm, adcsel, &auxval);
148
149         if (power_adc)
150                 wm97xx_reg_write(wm, AC97_EXTENDED_MID, power | 0x8000);
151
152         wm->codec->dig_restore(wm);
153
154         wm->pen_probably_down = 0;
155
156         mutex_unlock(&wm->codec_mutex);
157         return auxval & 0xfff;
158 }
159 EXPORT_SYMBOL_GPL(wm97xx_read_aux_adc);
160
161 /**
162  * wm97xx_get_gpio - Get the status of a codec GPIO.
163  * @wm: wm97xx device.
164  * @gpio: gpio
165  *
166  * Get the status of a codec GPIO pin
167  */
168
169 enum wm97xx_gpio_status wm97xx_get_gpio(struct wm97xx *wm, u32 gpio)
170 {
171         u16 status;
172         enum wm97xx_gpio_status ret;
173
174         mutex_lock(&wm->codec_mutex);
175         status = wm97xx_reg_read(wm, AC97_GPIO_STATUS);
176
177         if (status & gpio)
178                 ret = WM97XX_GPIO_HIGH;
179         else
180                 ret = WM97XX_GPIO_LOW;
181
182         mutex_unlock(&wm->codec_mutex);
183         return ret;
184 }
185 EXPORT_SYMBOL_GPL(wm97xx_get_gpio);
186
187 /**
188  * wm97xx_set_gpio - Set the status of a codec GPIO.
189  * @wm: wm97xx device.
190  * @gpio: gpio
191  *
192  *
193  * Set the status of a codec GPIO pin
194  */
195
196 void wm97xx_set_gpio(struct wm97xx *wm, u32 gpio,
197                                 enum wm97xx_gpio_status status)
198 {
199         u16 reg;
200
201         mutex_lock(&wm->codec_mutex);
202         reg = wm97xx_reg_read(wm, AC97_GPIO_STATUS);
203
204         if (status & WM97XX_GPIO_HIGH)
205                 reg |= gpio;
206         else
207                 reg &= ~gpio;
208
209         if (wm->id == WM9712_ID2)
210                 wm97xx_reg_write(wm, AC97_GPIO_STATUS, reg << 1);
211         else
212                 wm97xx_reg_write(wm, AC97_GPIO_STATUS, reg);
213         mutex_unlock(&wm->codec_mutex);
214 }
215 EXPORT_SYMBOL_GPL(wm97xx_set_gpio);
216
217 /*
218  * Codec GPIO pin configuration, this sets pin direction, polarity,
219  * stickyness and wake up.
220  */
221 void wm97xx_config_gpio(struct wm97xx *wm, u32 gpio, enum wm97xx_gpio_dir dir,
222                    enum wm97xx_gpio_pol pol, enum wm97xx_gpio_sticky sticky,
223                    enum wm97xx_gpio_wake wake)
224 {
225         u16 reg;
226
227         mutex_lock(&wm->codec_mutex);
228         reg = wm97xx_reg_read(wm, AC97_GPIO_POLARITY);
229
230         if (pol == WM97XX_GPIO_POL_HIGH)
231                 reg |= gpio;
232         else
233                 reg &= ~gpio;
234
235         wm97xx_reg_write(wm, AC97_GPIO_POLARITY, reg);
236         reg = wm97xx_reg_read(wm, AC97_GPIO_STICKY);
237
238         if (sticky == WM97XX_GPIO_STICKY)
239                 reg |= gpio;
240         else
241                 reg &= ~gpio;
242
243         wm97xx_reg_write(wm, AC97_GPIO_STICKY, reg);
244         reg = wm97xx_reg_read(wm, AC97_GPIO_WAKEUP);
245
246         if (wake == WM97XX_GPIO_WAKE)
247                 reg |= gpio;
248         else
249                 reg &= ~gpio;
250
251         wm97xx_reg_write(wm, AC97_GPIO_WAKEUP, reg);
252         reg = wm97xx_reg_read(wm, AC97_GPIO_CFG);
253
254         if (dir == WM97XX_GPIO_IN)
255                 reg |= gpio;
256         else
257                 reg &= ~gpio;
258
259         wm97xx_reg_write(wm, AC97_GPIO_CFG, reg);
260         mutex_unlock(&wm->codec_mutex);
261 }
262 EXPORT_SYMBOL_GPL(wm97xx_config_gpio);
263
264 /*
265  * Handle a pen down interrupt.
266  */
267 static void wm97xx_pen_irq_worker(struct work_struct *work)
268 {
269         struct wm97xx *wm = container_of(work, struct wm97xx, pen_event_work);
270         int pen_was_down = wm->pen_is_down;
271
272         /* do we need to enable the touch panel reader */
273         if (wm->id == WM9705_ID2) {
274                 if (wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD) &
275                                         WM97XX_PEN_DOWN)
276                         wm->pen_is_down = 1;
277                 else
278                         wm->pen_is_down = 0;
279         } else {
280                 u16 status, pol;
281                 mutex_lock(&wm->codec_mutex);
282                 status = wm97xx_reg_read(wm, AC97_GPIO_STATUS);
283                 pol = wm97xx_reg_read(wm, AC97_GPIO_POLARITY);
284
285                 if (WM97XX_GPIO_13 & pol & status) {
286                         wm->pen_is_down = 1;
287                         wm97xx_reg_write(wm, AC97_GPIO_POLARITY, pol &
288                                                 ~WM97XX_GPIO_13);
289                 } else {
290                         wm->pen_is_down = 0;
291                         wm97xx_reg_write(wm, AC97_GPIO_POLARITY, pol |
292                                          WM97XX_GPIO_13);
293                 }
294
295                 if (wm->id == WM9712_ID2)
296                         wm97xx_reg_write(wm, AC97_GPIO_STATUS, (status &
297                                                 ~WM97XX_GPIO_13) << 1);
298                 else
299                         wm97xx_reg_write(wm, AC97_GPIO_STATUS, status &
300                                                 ~WM97XX_GPIO_13);
301                 mutex_unlock(&wm->codec_mutex);
302         }
303
304         /* If the system is not using continuous mode or it provides a
305          * pen down operation then we need to schedule polls while the
306          * pen is down.  Otherwise the machine driver is responsible
307          * for scheduling reads.
308          */
309         if (!wm->mach_ops->acc_enabled || wm->mach_ops->acc_pen_down) {
310                 if (wm->pen_is_down && !pen_was_down) {
311                         /* Data is not availiable immediately on pen down */
312                         queue_delayed_work(wm->ts_workq, &wm->ts_reader, 1);
313                 }
314
315                 /* Let ts_reader report the pen up for debounce. */
316                 if (!wm->pen_is_down && pen_was_down)
317                         wm->pen_is_down = 1;
318         }
319
320         if (!wm->pen_is_down && wm->mach_ops->acc_enabled)
321                 wm->mach_ops->acc_pen_up(wm);
322
323         wm->mach_ops->irq_enable(wm, 1);
324 }
325
326 /*
327  * Codec PENDOWN irq handler
328  *
329  * We have to disable the codec interrupt in the handler because it
330  * can take upto 1ms to clear the interrupt source. We schedule a task
331  * in a work queue to do the actual interaction with the chip (it
332  * doesn't matter if we end up reenqueing it before it is executed
333  * since we don't touch the chip until it has run).  The interrupt is
334  * then enabled again in the slow handler when the source has been
335  * cleared.
336  */
337 static irqreturn_t wm97xx_pen_interrupt(int irq, void *dev_id)
338 {
339         struct wm97xx *wm = dev_id;
340
341         wm->mach_ops->irq_enable(wm, 0);
342         queue_work(wm->ts_workq, &wm->pen_event_work);
343
344         return IRQ_HANDLED;
345 }
346
347 /*
348  * initialise pen IRQ handler and workqueue
349  */
350 static int wm97xx_init_pen_irq(struct wm97xx *wm)
351 {
352         u16 reg;
353
354         /* If an interrupt is supplied an IRQ enable operation must also be
355          * provided. */
356         BUG_ON(!wm->mach_ops->irq_enable);
357
358         if (request_irq(wm->pen_irq, wm97xx_pen_interrupt, IRQF_SHARED,
359                         "wm97xx-pen", wm)) {
360                 dev_err(wm->dev,
361                         "Failed to register pen down interrupt, polling");
362                 wm->pen_irq = 0;
363                 return -EINVAL;
364         }
365
366         /* Configure GPIO as interrupt source on WM971x */
367         if (wm->id != WM9705_ID2) {
368                 BUG_ON(!wm->mach_ops->irq_gpio);
369                 reg = wm97xx_reg_read(wm, AC97_MISC_AFE);
370                 wm97xx_reg_write(wm, AC97_MISC_AFE,
371                                 reg & ~(wm->mach_ops->irq_gpio));
372                 reg = wm97xx_reg_read(wm, 0x5a);
373                 wm97xx_reg_write(wm, 0x5a, reg & ~0x0001);
374         }
375
376         return 0;
377 }
378
379 static int wm97xx_read_samples(struct wm97xx *wm)
380 {
381         struct wm97xx_data data;
382         int rc;
383
384         mutex_lock(&wm->codec_mutex);
385
386         if (wm->mach_ops && wm->mach_ops->acc_enabled)
387                 rc = wm->mach_ops->acc_pen_down(wm);
388         else
389                 rc = wm->codec->poll_touch(wm, &data);
390
391         if (rc & RC_PENUP) {
392                 if (wm->pen_is_down) {
393                         wm->pen_is_down = 0;
394                         dev_dbg(wm->dev, "pen up\n");
395                         input_report_abs(wm->input_dev, ABS_PRESSURE, 0);
396                         input_sync(wm->input_dev);
397                 } else if (!(rc & RC_AGAIN)) {
398                         /* We need high frequency updates only while
399                         * pen is down, the user never will be able to
400                         * touch screen faster than a few times per
401                         * second... On the other hand, when the user
402                         * is actively working with the touchscreen we
403                         * don't want to lose the quick response. So we
404                         * will slowly increase sleep time after the
405                         * pen is up and quicky restore it to ~one task
406                         * switch when pen is down again.
407                         */
408                         if (wm->ts_reader_interval < HZ / 10)
409                                 wm->ts_reader_interval++;
410                 }
411
412         } else if (rc & RC_VALID) {
413                 dev_dbg(wm->dev,
414                         "pen down: x=%x:%d, y=%x:%d, pressure=%x:%d\n",
415                         data.x >> 12, data.x & 0xfff, data.y >> 12,
416                         data.y & 0xfff, data.p >> 12, data.p & 0xfff);
417                 input_report_abs(wm->input_dev, ABS_X, data.x & 0xfff);
418                 input_report_abs(wm->input_dev, ABS_Y, data.y & 0xfff);
419                 input_report_abs(wm->input_dev, ABS_PRESSURE, data.p & 0xfff);
420                 input_sync(wm->input_dev);
421                 wm->pen_is_down = 1;
422                 wm->ts_reader_interval = wm->ts_reader_min_interval;
423         } else if (rc & RC_PENDOWN) {
424                 dev_dbg(wm->dev, "pen down\n");
425                 wm->pen_is_down = 1;
426                 wm->ts_reader_interval = wm->ts_reader_min_interval;
427         }
428
429         mutex_unlock(&wm->codec_mutex);
430         return rc;
431 }
432
433 /*
434 * The touchscreen sample reader.
435 */
436 static void wm97xx_ts_reader(struct work_struct *work)
437 {
438         int rc;
439         struct wm97xx *wm = container_of(work, struct wm97xx, ts_reader.work);
440
441         BUG_ON(!wm->codec);
442
443         do {
444                 rc = wm97xx_read_samples(wm);
445         } while (rc & RC_AGAIN);
446
447         if (wm->pen_is_down || !wm->pen_irq)
448                 queue_delayed_work(wm->ts_workq, &wm->ts_reader,
449                                    wm->ts_reader_interval);
450 }
451
452 /**
453  * wm97xx_ts_input_open - Open the touch screen input device.
454  * @idev:       Input device to be opened.
455  *
456  * Called by the input sub system to open a wm97xx touchscreen device.
457  * Starts the touchscreen thread and touch digitiser.
458  */
459 static int wm97xx_ts_input_open(struct input_dev *idev)
460 {
461         struct wm97xx *wm = input_get_drvdata(idev);
462
463         wm->ts_workq = create_singlethread_workqueue("kwm97xx");
464         if (wm->ts_workq == NULL) {
465                 dev_err(wm->dev,
466                         "Failed to create workqueue\n");
467                 return -EINVAL;
468         }
469
470         /* start digitiser */
471         if (wm->mach_ops && wm->mach_ops->acc_enabled)
472                 wm->codec->acc_enable(wm, 1);
473         wm->codec->dig_enable(wm, 1);
474
475         INIT_DELAYED_WORK(&wm->ts_reader, wm97xx_ts_reader);
476         INIT_WORK(&wm->pen_event_work, wm97xx_pen_irq_worker);
477
478         wm->ts_reader_min_interval = HZ >= 100 ? HZ / 100 : 1;
479         if (wm->ts_reader_min_interval < 1)
480                 wm->ts_reader_min_interval = 1;
481         wm->ts_reader_interval = wm->ts_reader_min_interval;
482
483         wm->pen_is_down = 0;
484         if (wm->pen_irq)
485                 wm97xx_init_pen_irq(wm);
486         else
487                 dev_err(wm->dev, "No IRQ specified\n");
488
489         /* If we either don't have an interrupt for pen down events or
490          * failed to acquire it then we need to poll.
491          */
492         if (wm->pen_irq == 0)
493                 queue_delayed_work(wm->ts_workq, &wm->ts_reader,
494                                    wm->ts_reader_interval);
495
496         return 0;
497 }
498
499 /**
500  * wm97xx_ts_input_close - Close the touch screen input device.
501  * @idev:       Input device to be closed.
502  *
503  * Called by the input sub system to close a wm97xx touchscreen
504  * device.  Kills the touchscreen thread and stops the touch
505  * digitiser.
506  */
507
508 static void wm97xx_ts_input_close(struct input_dev *idev)
509 {
510         struct wm97xx *wm = input_get_drvdata(idev);
511         u16 reg;
512
513         if (wm->pen_irq) {
514                 /* Return the interrupt to GPIO usage (disabling it) */
515                 if (wm->id != WM9705_ID2) {
516                         BUG_ON(!wm->mach_ops->irq_gpio);
517                         reg = wm97xx_reg_read(wm, AC97_MISC_AFE);
518                         wm97xx_reg_write(wm, AC97_MISC_AFE,
519                                          reg | wm->mach_ops->irq_gpio);
520                 }
521
522                 free_irq(wm->pen_irq, wm);
523         }
524
525         wm->pen_is_down = 0;
526
527         /* Balance out interrupt disables/enables */
528         if (cancel_work_sync(&wm->pen_event_work))
529                 wm->mach_ops->irq_enable(wm, 1);
530
531         /* ts_reader rearms itself so we need to explicitly stop it
532          * before we destroy the workqueue.
533          */
534         cancel_delayed_work_sync(&wm->ts_reader);
535
536         destroy_workqueue(wm->ts_workq);
537
538         /* stop digitiser */
539         wm->codec->dig_enable(wm, 0);
540         if (wm->mach_ops && wm->mach_ops->acc_enabled)
541                 wm->codec->acc_enable(wm, 0);
542 }
543
544 static int wm97xx_probe(struct device *dev)
545 {
546         struct wm97xx *wm;
547         int ret = 0, id = 0;
548
549         wm = kzalloc(sizeof(struct wm97xx), GFP_KERNEL);
550         if (!wm)
551                 return -ENOMEM;
552         mutex_init(&wm->codec_mutex);
553
554         wm->dev = dev;
555         dev->driver_data = wm;
556         wm->ac97 = to_ac97_t(dev);
557
558         /* check that we have a supported codec */
559         id = wm97xx_reg_read(wm, AC97_VENDOR_ID1);
560         if (id != WM97XX_ID1) {
561                 dev_err(dev, "Device with vendor %04x is not a wm97xx\n", id);
562                 ret = -ENODEV;
563                 goto alloc_err;
564         }
565
566         wm->id = wm97xx_reg_read(wm, AC97_VENDOR_ID2);
567
568         dev_info(wm->dev, "detected a wm97%02x codec\n", wm->id & 0xff);
569
570         switch (wm->id & 0xff) {
571 #ifdef CONFIG_TOUCHSCREEN_WM9705
572         case 0x05:
573                 wm->codec = &wm9705_codec;
574                 break;
575 #endif
576 #ifdef CONFIG_TOUCHSCREEN_WM9712
577         case 0x12:
578                 wm->codec = &wm9712_codec;
579                 break;
580 #endif
581 #ifdef CONFIG_TOUCHSCREEN_WM9713
582         case 0x13:
583                 wm->codec = &wm9713_codec;
584                 break;
585 #endif
586         default:
587                 dev_err(wm->dev, "Support for wm97%02x not compiled in.\n",
588                         wm->id & 0xff);
589                 ret = -ENODEV;
590                 goto alloc_err;
591         }
592
593         wm->input_dev = input_allocate_device();
594         if (wm->input_dev == NULL) {
595                 ret = -ENOMEM;
596                 goto alloc_err;
597         }
598
599         /* set up touch configuration */
600         wm->input_dev->name = "wm97xx touchscreen";
601         wm->input_dev->open = wm97xx_ts_input_open;
602         wm->input_dev->close = wm97xx_ts_input_close;
603         set_bit(EV_ABS, wm->input_dev->evbit);
604         set_bit(ABS_X, wm->input_dev->absbit);
605         set_bit(ABS_Y, wm->input_dev->absbit);
606         set_bit(ABS_PRESSURE, wm->input_dev->absbit);
607         input_set_abs_params(wm->input_dev, ABS_X, abs_x[0], abs_x[1],
608                              abs_x[2], 0);
609         input_set_abs_params(wm->input_dev, ABS_Y, abs_y[0], abs_y[1],
610                              abs_y[2], 0);
611         input_set_abs_params(wm->input_dev, ABS_PRESSURE, abs_p[0], abs_p[1],
612                              abs_p[2], 0);
613         input_set_drvdata(wm->input_dev, wm);
614         wm->input_dev->dev.parent = dev;
615         ret = input_register_device(wm->input_dev);
616         if (ret < 0)
617                 goto dev_alloc_err;
618
619         /* set up physical characteristics */
620         wm->codec->phy_init(wm);
621
622         /* load gpio cache */
623         wm->gpio[0] = wm97xx_reg_read(wm, AC97_GPIO_CFG);
624         wm->gpio[1] = wm97xx_reg_read(wm, AC97_GPIO_POLARITY);
625         wm->gpio[2] = wm97xx_reg_read(wm, AC97_GPIO_STICKY);
626         wm->gpio[3] = wm97xx_reg_read(wm, AC97_GPIO_WAKEUP);
627         wm->gpio[4] = wm97xx_reg_read(wm, AC97_GPIO_STATUS);
628         wm->gpio[5] = wm97xx_reg_read(wm, AC97_MISC_AFE);
629
630         /* register our battery device */
631         wm->battery_dev = platform_device_alloc("wm97xx-battery", -1);
632         if (!wm->battery_dev) {
633                 ret = -ENOMEM;
634                 goto batt_err;
635         }
636         platform_set_drvdata(wm->battery_dev, wm);
637         wm->battery_dev->dev.parent = dev;
638         ret = platform_device_add(wm->battery_dev);
639         if (ret < 0)
640                 goto batt_reg_err;
641
642         /* register our extended touch device (for machine specific
643          * extensions) */
644         wm->touch_dev = platform_device_alloc("wm97xx-touch", -1);
645         if (!wm->touch_dev) {
646                 ret = -ENOMEM;
647                 goto touch_err;
648         }
649         platform_set_drvdata(wm->touch_dev, wm);
650         wm->touch_dev->dev.parent = dev;
651         ret = platform_device_add(wm->touch_dev);
652         if (ret < 0)
653                 goto touch_reg_err;
654
655         return ret;
656
657  touch_reg_err:
658         platform_device_put(wm->touch_dev);
659  touch_err:
660         platform_device_unregister(wm->battery_dev);
661         wm->battery_dev = NULL;
662  batt_reg_err:
663         platform_device_put(wm->battery_dev);
664  batt_err:
665         input_unregister_device(wm->input_dev);
666         wm->input_dev = NULL;
667  dev_alloc_err:
668         input_free_device(wm->input_dev);
669  alloc_err:
670         kfree(wm);
671
672         return ret;
673 }
674
675 static int wm97xx_remove(struct device *dev)
676 {
677         struct wm97xx *wm = dev_get_drvdata(dev);
678
679         platform_device_unregister(wm->battery_dev);
680         platform_device_unregister(wm->touch_dev);
681         input_unregister_device(wm->input_dev);
682         kfree(wm);
683
684         return 0;
685 }
686
687 #ifdef CONFIG_PM
688 static int wm97xx_suspend(struct device *dev, pm_message_t state)
689 {
690         struct wm97xx *wm = dev_get_drvdata(dev);
691
692         if (wm->input_dev->users)
693                 cancel_delayed_work_sync(&wm->ts_reader);
694
695         return 0;
696 }
697
698 static int wm97xx_resume(struct device *dev)
699 {
700         struct wm97xx *wm = dev_get_drvdata(dev);
701
702         /* restore digitiser and gpios */
703         if (wm->id == WM9713_ID2) {
704                 wm97xx_reg_write(wm, AC97_WM9713_DIG1, wm->dig[0]);
705                 wm97xx_reg_write(wm, 0x5a, wm->misc);
706                 if (wm->input_dev->users) {
707                         u16 reg;
708                         reg = wm97xx_reg_read(wm, AC97_EXTENDED_MID) & 0x7fff;
709                         wm97xx_reg_write(wm, AC97_EXTENDED_MID, reg);
710                 }
711         }
712
713         wm97xx_reg_write(wm, AC97_WM9713_DIG2, wm->dig[1]);
714         wm97xx_reg_write(wm, AC97_WM9713_DIG3, wm->dig[2]);
715
716         wm97xx_reg_write(wm, AC97_GPIO_CFG, wm->gpio[0]);
717         wm97xx_reg_write(wm, AC97_GPIO_POLARITY, wm->gpio[1]);
718         wm97xx_reg_write(wm, AC97_GPIO_STICKY, wm->gpio[2]);
719         wm97xx_reg_write(wm, AC97_GPIO_WAKEUP, wm->gpio[3]);
720         wm97xx_reg_write(wm, AC97_GPIO_STATUS, wm->gpio[4]);
721         wm97xx_reg_write(wm, AC97_MISC_AFE, wm->gpio[5]);
722
723         if (wm->input_dev->users && !wm->pen_irq) {
724                 wm->ts_reader_interval = wm->ts_reader_min_interval;
725                 queue_delayed_work(wm->ts_workq, &wm->ts_reader,
726                                    wm->ts_reader_interval);
727         }
728
729         return 0;
730 }
731
732 #else
733 #define wm97xx_suspend          NULL
734 #define wm97xx_resume           NULL
735 #endif
736
737 /*
738  * Machine specific operations
739  */
740 int wm97xx_register_mach_ops(struct wm97xx *wm,
741                              struct wm97xx_mach_ops *mach_ops)
742 {
743         mutex_lock(&wm->codec_mutex);
744         if (wm->mach_ops) {
745                 mutex_unlock(&wm->codec_mutex);
746                 return -EINVAL;
747         }
748         wm->mach_ops = mach_ops;
749         mutex_unlock(&wm->codec_mutex);
750
751         return 0;
752 }
753 EXPORT_SYMBOL_GPL(wm97xx_register_mach_ops);
754
755 void wm97xx_unregister_mach_ops(struct wm97xx *wm)
756 {
757         mutex_lock(&wm->codec_mutex);
758         wm->mach_ops = NULL;
759         mutex_unlock(&wm->codec_mutex);
760 }
761 EXPORT_SYMBOL_GPL(wm97xx_unregister_mach_ops);
762
763 static struct device_driver wm97xx_driver = {
764         .name =         "ac97",
765         .bus =          &ac97_bus_type,
766         .owner =        THIS_MODULE,
767         .probe =        wm97xx_probe,
768         .remove =       wm97xx_remove,
769         .suspend =      wm97xx_suspend,
770         .resume =       wm97xx_resume,
771 };
772
773 static int __init wm97xx_init(void)
774 {
775         return driver_register(&wm97xx_driver);
776 }
777
778 static void __exit wm97xx_exit(void)
779 {
780         driver_unregister(&wm97xx_driver);
781 }
782
783 module_init(wm97xx_init);
784 module_exit(wm97xx_exit);
785
786 /* Module information */
787 MODULE_AUTHOR("Liam Girdwood <liam.girdwood@wolfsonmicro.com>");
788 MODULE_DESCRIPTION("WM97xx Core - Touch Screen / AUX ADC / GPIO Driver");
789 MODULE_LICENSE("GPL");