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  * Configure the WM97XX_PRP value to use while system is suspended.
266  * If a value other than 0 is set then WM97xx pen detection will be
267  * left enabled in the configured mode while the system is in suspend,
268  * the device has users and suspend has not been disabled via the
269  * wakeup sysfs entries.
270  *
271  * @wm:   WM97xx device to configure
272  * @mode: WM97XX_PRP value to configure while suspended
273  */
274 void wm97xx_set_suspend_mode(struct wm97xx *wm, u16 mode)
275 {
276 	wm->suspend_mode = mode;
277 	device_init_wakeup(&wm->input_dev->dev, mode != 0);
278 }
279 EXPORT_SYMBOL_GPL(wm97xx_set_suspend_mode);
280 
281 /*
282  * Handle a pen down interrupt.
283  */
284 static void wm97xx_pen_irq_worker(struct work_struct *work)
285 {
286 	struct wm97xx *wm = container_of(work, struct wm97xx, pen_event_work);
287 	int pen_was_down = wm->pen_is_down;
288 
289 	/* do we need to enable the touch panel reader */
290 	if (wm->id == WM9705_ID2) {
291 		if (wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD) &
292 					WM97XX_PEN_DOWN)
293 			wm->pen_is_down = 1;
294 		else
295 			wm->pen_is_down = 0;
296 	} else {
297 		u16 status, pol;
298 		mutex_lock(&wm->codec_mutex);
299 		status = wm97xx_reg_read(wm, AC97_GPIO_STATUS);
300 		pol = wm97xx_reg_read(wm, AC97_GPIO_POLARITY);
301 
302 		if (WM97XX_GPIO_13 & pol & status) {
303 			wm->pen_is_down = 1;
304 			wm97xx_reg_write(wm, AC97_GPIO_POLARITY, pol &
305 						~WM97XX_GPIO_13);
306 		} else {
307 			wm->pen_is_down = 0;
308 			wm97xx_reg_write(wm, AC97_GPIO_POLARITY, pol |
309 					 WM97XX_GPIO_13);
310 		}
311 
312 		if (wm->id == WM9712_ID2)
313 			wm97xx_reg_write(wm, AC97_GPIO_STATUS, (status &
314 						~WM97XX_GPIO_13) << 1);
315 		else
316 			wm97xx_reg_write(wm, AC97_GPIO_STATUS, status &
317 						~WM97XX_GPIO_13);
318 		mutex_unlock(&wm->codec_mutex);
319 	}
320 
321 	/* If the system is not using continuous mode or it provides a
322 	 * pen down operation then we need to schedule polls while the
323 	 * pen is down.  Otherwise the machine driver is responsible
324 	 * for scheduling reads.
325 	 */
326 	if (!wm->mach_ops->acc_enabled || wm->mach_ops->acc_pen_down) {
327 		if (wm->pen_is_down && !pen_was_down) {
328 			/* Data is not availiable immediately on pen down */
329 			queue_delayed_work(wm->ts_workq, &wm->ts_reader, 1);
330 		}
331 
332 		/* Let ts_reader report the pen up for debounce. */
333 		if (!wm->pen_is_down && pen_was_down)
334 			wm->pen_is_down = 1;
335 	}
336 
337 	if (!wm->pen_is_down && wm->mach_ops->acc_enabled)
338 		wm->mach_ops->acc_pen_up(wm);
339 
340 	wm->mach_ops->irq_enable(wm, 1);
341 }
342 
343 /*
344  * Codec PENDOWN irq handler
345  *
346  * We have to disable the codec interrupt in the handler because it
347  * can take upto 1ms to clear the interrupt source. We schedule a task
348  * in a work queue to do the actual interaction with the chip.  The
349  * interrupt is then enabled again in the slow handler when the source
350  * has been cleared.
351  */
352 static irqreturn_t wm97xx_pen_interrupt(int irq, void *dev_id)
353 {
354 	struct wm97xx *wm = dev_id;
355 
356 	if (!work_pending(&wm->pen_event_work)) {
357 		wm->mach_ops->irq_enable(wm, 0);
358 		queue_work(wm->ts_workq, &wm->pen_event_work);
359 	}
360 
361 	return IRQ_HANDLED;
362 }
363 
364 /*
365  * initialise pen IRQ handler and workqueue
366  */
367 static int wm97xx_init_pen_irq(struct wm97xx *wm)
368 {
369 	u16 reg;
370 
371 	/* If an interrupt is supplied an IRQ enable operation must also be
372 	 * provided. */
373 	BUG_ON(!wm->mach_ops->irq_enable);
374 
375 	if (request_irq(wm->pen_irq, wm97xx_pen_interrupt,
376 			IRQF_SHARED | IRQF_SAMPLE_RANDOM,
377 			"wm97xx-pen", wm)) {
378 		dev_err(wm->dev,
379 			"Failed to register pen down interrupt, polling");
380 		wm->pen_irq = 0;
381 		return -EINVAL;
382 	}
383 
384 	/* Configure GPIO as interrupt source on WM971x */
385 	if (wm->id != WM9705_ID2) {
386 		BUG_ON(!wm->mach_ops->irq_gpio);
387 		reg = wm97xx_reg_read(wm, AC97_MISC_AFE);
388 		wm97xx_reg_write(wm, AC97_MISC_AFE,
389 				reg & ~(wm->mach_ops->irq_gpio));
390 		reg = wm97xx_reg_read(wm, 0x5a);
391 		wm97xx_reg_write(wm, 0x5a, reg & ~0x0001);
392 	}
393 
394 	return 0;
395 }
396 
397 static int wm97xx_read_samples(struct wm97xx *wm)
398 {
399 	struct wm97xx_data data;
400 	int rc;
401 
402 	mutex_lock(&wm->codec_mutex);
403 
404 	if (wm->mach_ops && wm->mach_ops->acc_enabled)
405 		rc = wm->mach_ops->acc_pen_down(wm);
406 	else
407 		rc = wm->codec->poll_touch(wm, &data);
408 
409 	if (rc & RC_PENUP) {
410 		if (wm->pen_is_down) {
411 			wm->pen_is_down = 0;
412 			dev_dbg(wm->dev, "pen up\n");
413 			input_report_abs(wm->input_dev, ABS_PRESSURE, 0);
414 			input_sync(wm->input_dev);
415 		} else if (!(rc & RC_AGAIN)) {
416 			/* We need high frequency updates only while
417 			* pen is down, the user never will be able to
418 			* touch screen faster than a few times per
419 			* second... On the other hand, when the user
420 			* is actively working with the touchscreen we
421 			* don't want to lose the quick response. So we
422 			* will slowly increase sleep time after the
423 			* pen is up and quicky restore it to ~one task
424 			* switch when pen is down again.
425 			*/
426 			if (wm->ts_reader_interval < HZ / 10)
427 				wm->ts_reader_interval++;
428 		}
429 
430 	} else if (rc & RC_VALID) {
431 		dev_dbg(wm->dev,
432 			"pen down: x=%x:%d, y=%x:%d, pressure=%x:%d\n",
433 			data.x >> 12, data.x & 0xfff, data.y >> 12,
434 			data.y & 0xfff, data.p >> 12, data.p & 0xfff);
435 		input_report_abs(wm->input_dev, ABS_X, data.x & 0xfff);
436 		input_report_abs(wm->input_dev, ABS_Y, data.y & 0xfff);
437 		input_report_abs(wm->input_dev, ABS_PRESSURE, data.p & 0xfff);
438 		input_sync(wm->input_dev);
439 		wm->pen_is_down = 1;
440 		wm->ts_reader_interval = wm->ts_reader_min_interval;
441 	} else if (rc & RC_PENDOWN) {
442 		dev_dbg(wm->dev, "pen down\n");
443 		wm->pen_is_down = 1;
444 		wm->ts_reader_interval = wm->ts_reader_min_interval;
445 	}
446 
447 	mutex_unlock(&wm->codec_mutex);
448 	return rc;
449 }
450 
451 /*
452 * The touchscreen sample reader.
453 */
454 static void wm97xx_ts_reader(struct work_struct *work)
455 {
456 	int rc;
457 	struct wm97xx *wm = container_of(work, struct wm97xx, ts_reader.work);
458 
459 	BUG_ON(!wm->codec);
460 
461 	do {
462 		rc = wm97xx_read_samples(wm);
463 	} while (rc & RC_AGAIN);
464 
465 	if (wm->pen_is_down || !wm->pen_irq)
466 		queue_delayed_work(wm->ts_workq, &wm->ts_reader,
467 				   wm->ts_reader_interval);
468 }
469 
470 /**
471  * wm97xx_ts_input_open - Open the touch screen input device.
472  * @idev:	Input device to be opened.
473  *
474  * Called by the input sub system to open a wm97xx touchscreen device.
475  * Starts the touchscreen thread and touch digitiser.
476  */
477 static int wm97xx_ts_input_open(struct input_dev *idev)
478 {
479 	struct wm97xx *wm = input_get_drvdata(idev);
480 
481 	wm->ts_workq = create_singlethread_workqueue("kwm97xx");
482 	if (wm->ts_workq == NULL) {
483 		dev_err(wm->dev,
484 			"Failed to create workqueue\n");
485 		return -EINVAL;
486 	}
487 
488 	/* start digitiser */
489 	if (wm->mach_ops && wm->mach_ops->acc_enabled)
490 		wm->codec->acc_enable(wm, 1);
491 	wm->codec->dig_enable(wm, 1);
492 
493 	INIT_DELAYED_WORK(&wm->ts_reader, wm97xx_ts_reader);
494 	INIT_WORK(&wm->pen_event_work, wm97xx_pen_irq_worker);
495 
496 	wm->ts_reader_min_interval = HZ >= 100 ? HZ / 100 : 1;
497 	if (wm->ts_reader_min_interval < 1)
498 		wm->ts_reader_min_interval = 1;
499 	wm->ts_reader_interval = wm->ts_reader_min_interval;
500 
501 	wm->pen_is_down = 0;
502 	if (wm->pen_irq)
503 		wm97xx_init_pen_irq(wm);
504 	else
505 		dev_err(wm->dev, "No IRQ specified\n");
506 
507 	/* If we either don't have an interrupt for pen down events or
508 	 * failed to acquire it then we need to poll.
509 	 */
510 	if (wm->pen_irq == 0)
511 		queue_delayed_work(wm->ts_workq, &wm->ts_reader,
512 				   wm->ts_reader_interval);
513 
514 	return 0;
515 }
516 
517 /**
518  * wm97xx_ts_input_close - Close the touch screen input device.
519  * @idev:	Input device to be closed.
520  *
521  * Called by the input sub system to close a wm97xx touchscreen
522  * device.  Kills the touchscreen thread and stops the touch
523  * digitiser.
524  */
525 
526 static void wm97xx_ts_input_close(struct input_dev *idev)
527 {
528 	struct wm97xx *wm = input_get_drvdata(idev);
529 	u16 reg;
530 
531 	if (wm->pen_irq) {
532 		/* Return the interrupt to GPIO usage (disabling it) */
533 		if (wm->id != WM9705_ID2) {
534 			BUG_ON(!wm->mach_ops->irq_gpio);
535 			reg = wm97xx_reg_read(wm, AC97_MISC_AFE);
536 			wm97xx_reg_write(wm, AC97_MISC_AFE,
537 					 reg | wm->mach_ops->irq_gpio);
538 		}
539 
540 		free_irq(wm->pen_irq, wm);
541 	}
542 
543 	wm->pen_is_down = 0;
544 
545 	/* Balance out interrupt disables/enables */
546 	if (cancel_work_sync(&wm->pen_event_work))
547 		wm->mach_ops->irq_enable(wm, 1);
548 
549 	/* ts_reader rearms itself so we need to explicitly stop it
550 	 * before we destroy the workqueue.
551 	 */
552 	cancel_delayed_work_sync(&wm->ts_reader);
553 
554 	destroy_workqueue(wm->ts_workq);
555 
556 	/* stop digitiser */
557 	wm->codec->dig_enable(wm, 0);
558 	if (wm->mach_ops && wm->mach_ops->acc_enabled)
559 		wm->codec->acc_enable(wm, 0);
560 }
561 
562 static int wm97xx_probe(struct device *dev)
563 {
564 	struct wm97xx *wm;
565 	int ret = 0, id = 0;
566 
567 	wm = kzalloc(sizeof(struct wm97xx), GFP_KERNEL);
568 	if (!wm)
569 		return -ENOMEM;
570 	mutex_init(&wm->codec_mutex);
571 
572 	wm->dev = dev;
573 	dev->driver_data = wm;
574 	wm->ac97 = to_ac97_t(dev);
575 
576 	/* check that we have a supported codec */
577 	id = wm97xx_reg_read(wm, AC97_VENDOR_ID1);
578 	if (id != WM97XX_ID1) {
579 		dev_err(dev, "Device with vendor %04x is not a wm97xx\n", id);
580 		ret = -ENODEV;
581 		goto alloc_err;
582 	}
583 
584 	wm->id = wm97xx_reg_read(wm, AC97_VENDOR_ID2);
585 
586 	dev_info(wm->dev, "detected a wm97%02x codec\n", wm->id & 0xff);
587 
588 	switch (wm->id & 0xff) {
589 #ifdef CONFIG_TOUCHSCREEN_WM9705
590 	case 0x05:
591 		wm->codec = &wm9705_codec;
592 		break;
593 #endif
594 #ifdef CONFIG_TOUCHSCREEN_WM9712
595 	case 0x12:
596 		wm->codec = &wm9712_codec;
597 		break;
598 #endif
599 #ifdef CONFIG_TOUCHSCREEN_WM9713
600 	case 0x13:
601 		wm->codec = &wm9713_codec;
602 		break;
603 #endif
604 	default:
605 		dev_err(wm->dev, "Support for wm97%02x not compiled in.\n",
606 			wm->id & 0xff);
607 		ret = -ENODEV;
608 		goto alloc_err;
609 	}
610 
611 	/* set up physical characteristics */
612 	wm->codec->phy_init(wm);
613 
614 	/* load gpio cache */
615 	wm->gpio[0] = wm97xx_reg_read(wm, AC97_GPIO_CFG);
616 	wm->gpio[1] = wm97xx_reg_read(wm, AC97_GPIO_POLARITY);
617 	wm->gpio[2] = wm97xx_reg_read(wm, AC97_GPIO_STICKY);
618 	wm->gpio[3] = wm97xx_reg_read(wm, AC97_GPIO_WAKEUP);
619 	wm->gpio[4] = wm97xx_reg_read(wm, AC97_GPIO_STATUS);
620 	wm->gpio[5] = wm97xx_reg_read(wm, AC97_MISC_AFE);
621 
622 	wm->input_dev = input_allocate_device();
623 	if (wm->input_dev == NULL) {
624 		ret = -ENOMEM;
625 		goto alloc_err;
626 	}
627 
628 	/* set up touch configuration */
629 	wm->input_dev->name = "wm97xx touchscreen";
630 	wm->input_dev->phys = "wm97xx";
631 	wm->input_dev->open = wm97xx_ts_input_open;
632 	wm->input_dev->close = wm97xx_ts_input_close;
633 	set_bit(EV_ABS, wm->input_dev->evbit);
634 	set_bit(ABS_X, wm->input_dev->absbit);
635 	set_bit(ABS_Y, wm->input_dev->absbit);
636 	set_bit(ABS_PRESSURE, wm->input_dev->absbit);
637 	input_set_abs_params(wm->input_dev, ABS_X, abs_x[0], abs_x[1],
638 			     abs_x[2], 0);
639 	input_set_abs_params(wm->input_dev, ABS_Y, abs_y[0], abs_y[1],
640 			     abs_y[2], 0);
641 	input_set_abs_params(wm->input_dev, ABS_PRESSURE, abs_p[0], abs_p[1],
642 			     abs_p[2], 0);
643 	input_set_drvdata(wm->input_dev, wm);
644 	wm->input_dev->dev.parent = dev;
645 	ret = input_register_device(wm->input_dev);
646 	if (ret < 0)
647 		goto dev_alloc_err;
648 
649 	/* register our battery device */
650 	wm->battery_dev = platform_device_alloc("wm97xx-battery", -1);
651 	if (!wm->battery_dev) {
652 		ret = -ENOMEM;
653 		goto batt_err;
654 	}
655 	platform_set_drvdata(wm->battery_dev, wm);
656 	wm->battery_dev->dev.parent = dev;
657 	ret = platform_device_add(wm->battery_dev);
658 	if (ret < 0)
659 		goto batt_reg_err;
660 
661 	/* register our extended touch device (for machine specific
662 	 * extensions) */
663 	wm->touch_dev = platform_device_alloc("wm97xx-touch", -1);
664 	if (!wm->touch_dev) {
665 		ret = -ENOMEM;
666 		goto touch_err;
667 	}
668 	platform_set_drvdata(wm->touch_dev, wm);
669 	wm->touch_dev->dev.parent = dev;
670 	ret = platform_device_add(wm->touch_dev);
671 	if (ret < 0)
672 		goto touch_reg_err;
673 
674 	return ret;
675 
676  touch_reg_err:
677 	platform_device_put(wm->touch_dev);
678  touch_err:
679 	platform_device_unregister(wm->battery_dev);
680 	wm->battery_dev = NULL;
681  batt_reg_err:
682 	platform_device_put(wm->battery_dev);
683  batt_err:
684 	input_unregister_device(wm->input_dev);
685 	wm->input_dev = NULL;
686  dev_alloc_err:
687 	input_free_device(wm->input_dev);
688  alloc_err:
689 	kfree(wm);
690 
691 	return ret;
692 }
693 
694 static int wm97xx_remove(struct device *dev)
695 {
696 	struct wm97xx *wm = dev_get_drvdata(dev);
697 
698 	platform_device_unregister(wm->battery_dev);
699 	platform_device_unregister(wm->touch_dev);
700 	input_unregister_device(wm->input_dev);
701 	kfree(wm);
702 
703 	return 0;
704 }
705 
706 #ifdef CONFIG_PM
707 static int wm97xx_suspend(struct device *dev, pm_message_t state)
708 {
709 	struct wm97xx *wm = dev_get_drvdata(dev);
710 	u16 reg;
711 	int suspend_mode;
712 
713 	if (device_may_wakeup(&wm->input_dev->dev))
714 		suspend_mode = wm->suspend_mode;
715 	else
716 		suspend_mode = 0;
717 
718 	if (wm->input_dev->users)
719 		cancel_delayed_work_sync(&wm->ts_reader);
720 
721 	/* Power down the digitiser (bypassing the cache for resume) */
722 	reg = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER2);
723 	reg &= ~WM97XX_PRP_DET_DIG;
724 	if (wm->input_dev->users)
725 		reg |= suspend_mode;
726 	wm->ac97->bus->ops->write(wm->ac97, AC97_WM97XX_DIGITISER2, reg);
727 
728 	/* WM9713 has an additional power bit - turn it off if there
729 	 * are no users or if suspend mode is zero. */
730 	if (wm->id == WM9713_ID2 &&
731 	    (!wm->input_dev->users || !suspend_mode)) {
732 		reg = wm97xx_reg_read(wm, AC97_EXTENDED_MID) | 0x8000;
733 		wm97xx_reg_write(wm, AC97_EXTENDED_MID, reg);
734 	}
735 
736 	return 0;
737 }
738 
739 static int wm97xx_resume(struct device *dev)
740 {
741 	struct wm97xx *wm = dev_get_drvdata(dev);
742 
743 	/* restore digitiser and gpios */
744 	if (wm->id == WM9713_ID2) {
745 		wm97xx_reg_write(wm, AC97_WM9713_DIG1, wm->dig[0]);
746 		wm97xx_reg_write(wm, 0x5a, wm->misc);
747 		if (wm->input_dev->users) {
748 			u16 reg;
749 			reg = wm97xx_reg_read(wm, AC97_EXTENDED_MID) & 0x7fff;
750 			wm97xx_reg_write(wm, AC97_EXTENDED_MID, reg);
751 		}
752 	}
753 
754 	wm97xx_reg_write(wm, AC97_WM9713_DIG2, wm->dig[1]);
755 	wm97xx_reg_write(wm, AC97_WM9713_DIG3, wm->dig[2]);
756 
757 	wm97xx_reg_write(wm, AC97_GPIO_CFG, wm->gpio[0]);
758 	wm97xx_reg_write(wm, AC97_GPIO_POLARITY, wm->gpio[1]);
759 	wm97xx_reg_write(wm, AC97_GPIO_STICKY, wm->gpio[2]);
760 	wm97xx_reg_write(wm, AC97_GPIO_WAKEUP, wm->gpio[3]);
761 	wm97xx_reg_write(wm, AC97_GPIO_STATUS, wm->gpio[4]);
762 	wm97xx_reg_write(wm, AC97_MISC_AFE, wm->gpio[5]);
763 
764 	if (wm->input_dev->users && !wm->pen_irq) {
765 		wm->ts_reader_interval = wm->ts_reader_min_interval;
766 		queue_delayed_work(wm->ts_workq, &wm->ts_reader,
767 				   wm->ts_reader_interval);
768 	}
769 
770 	return 0;
771 }
772 
773 #else
774 #define wm97xx_suspend		NULL
775 #define wm97xx_resume		NULL
776 #endif
777 
778 /*
779  * Machine specific operations
780  */
781 int wm97xx_register_mach_ops(struct wm97xx *wm,
782 			     struct wm97xx_mach_ops *mach_ops)
783 {
784 	mutex_lock(&wm->codec_mutex);
785 	if (wm->mach_ops) {
786 		mutex_unlock(&wm->codec_mutex);
787 		return -EINVAL;
788 	}
789 	wm->mach_ops = mach_ops;
790 	mutex_unlock(&wm->codec_mutex);
791 
792 	return 0;
793 }
794 EXPORT_SYMBOL_GPL(wm97xx_register_mach_ops);
795 
796 void wm97xx_unregister_mach_ops(struct wm97xx *wm)
797 {
798 	mutex_lock(&wm->codec_mutex);
799 	wm->mach_ops = NULL;
800 	mutex_unlock(&wm->codec_mutex);
801 }
802 EXPORT_SYMBOL_GPL(wm97xx_unregister_mach_ops);
803 
804 static struct device_driver wm97xx_driver = {
805 	.name =		"wm97xx-ts",
806 	.bus =		&ac97_bus_type,
807 	.owner =	THIS_MODULE,
808 	.probe =	wm97xx_probe,
809 	.remove =	wm97xx_remove,
810 	.suspend =	wm97xx_suspend,
811 	.resume =	wm97xx_resume,
812 };
813 
814 static int __init wm97xx_init(void)
815 {
816 	return driver_register(&wm97xx_driver);
817 }
818 
819 static void __exit wm97xx_exit(void)
820 {
821 	driver_unregister(&wm97xx_driver);
822 }
823 
824 module_init(wm97xx_init);
825 module_exit(wm97xx_exit);
826 
827 /* Module information */
828 MODULE_AUTHOR("Liam Girdwood <liam.girdwood@wolfsonmicro.com>");
829 MODULE_DESCRIPTION("WM97xx Core - Touch Screen / AUX ADC / GPIO Driver");
830 MODULE_LICENSE("GPL");
831