xref: /linux/drivers/input/touchscreen/wm97xx-core.c (revision 3c4fc7bf4c9e66fe71abcbf93f62f4ddb89b7f15)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * wm97xx-core.c  --  Touch screen driver core for Wolfson WM9705, WM9712
4  *                    and WM9713 AC97 Codecs.
5  *
6  * Copyright 2003, 2004, 2005, 2006, 2007, 2008 Wolfson Microelectronics PLC.
7  * Author: Liam Girdwood <lrg@slimlogic.co.uk>
8  * Parts Copyright : Ian Molton <spyro@f2s.com>
9  *                   Andrew Zabolotny <zap@homelink.ru>
10  *                   Russell King <rmk@arm.linux.org.uk>
11  *
12  * Notes:
13  *
14  *  Features:
15  *       - supports WM9705, WM9712, WM9713
16  *       - polling mode
17  *       - continuous mode (arch-dependent)
18  *       - adjustable rpu/dpp settings
19  *       - adjustable pressure current
20  *       - adjustable sample settle delay
21  *       - 4 and 5 wire touchscreens (5 wire is WM9712 only)
22  *       - pen down detection
23  *       - battery monitor
24  *       - sample AUX adcs
25  *       - power management
26  *       - codec GPIO
27  *       - codec event notification
28  * Todo
29  *       - Support for async sampling control for noisy LCDs.
30  */
31 
32 #include <linux/module.h>
33 #include <linux/moduleparam.h>
34 #include <linux/kernel.h>
35 #include <linux/init.h>
36 #include <linux/delay.h>
37 #include <linux/string.h>
38 #include <linux/proc_fs.h>
39 #include <linux/pm.h>
40 #include <linux/interrupt.h>
41 #include <linux/bitops.h>
42 #include <linux/mfd/wm97xx.h>
43 #include <linux/workqueue.h>
44 #include <linux/wm97xx.h>
45 #include <linux/uaccess.h>
46 #include <linux/io.h>
47 #include <linux/slab.h>
48 
49 #define TS_NAME			"wm97xx"
50 #define WM_CORE_VERSION		"1.00"
51 #define DEFAULT_PRESSURE	0xb0c0
52 
53 
54 /*
55  * Touchscreen absolute values
56  *
57  * These parameters are used to help the input layer discard out of
58  * range readings and reduce jitter etc.
59  *
60  *   o min, max:- indicate the min and max values your touch screen returns
61  *   o fuzz:- use a higher number to reduce jitter
62  *
63  * The default values correspond to Mainstone II in QVGA mode
64  *
65  * Please read
66  * Documentation/input/input-programming.rst for more details.
67  */
68 
69 static int abs_x[3] = {150, 4000, 5};
70 module_param_array(abs_x, int, NULL, 0);
71 MODULE_PARM_DESC(abs_x, "Touchscreen absolute X min, max, fuzz");
72 
73 static int abs_y[3] = {200, 4000, 40};
74 module_param_array(abs_y, int, NULL, 0);
75 MODULE_PARM_DESC(abs_y, "Touchscreen absolute Y min, max, fuzz");
76 
77 static int abs_p[3] = {0, 150, 4};
78 module_param_array(abs_p, int, NULL, 0);
79 MODULE_PARM_DESC(abs_p, "Touchscreen absolute Pressure min, max, fuzz");
80 
81 /*
82  * wm97xx IO access, all IO locking done by AC97 layer
83  */
84 int wm97xx_reg_read(struct wm97xx *wm, u16 reg)
85 {
86 	if (wm->ac97)
87 		return wm->ac97->bus->ops->read(wm->ac97, reg);
88 	else
89 		return -1;
90 }
91 EXPORT_SYMBOL_GPL(wm97xx_reg_read);
92 
93 void wm97xx_reg_write(struct wm97xx *wm, u16 reg, u16 val)
94 {
95 	/* cache digitiser registers */
96 	if (reg >= AC97_WM9713_DIG1 && reg <= AC97_WM9713_DIG3)
97 		wm->dig[(reg - AC97_WM9713_DIG1) >> 1] = val;
98 
99 	/* cache gpio regs */
100 	if (reg >= AC97_GPIO_CFG && reg <= AC97_MISC_AFE)
101 		wm->gpio[(reg - AC97_GPIO_CFG) >> 1] = val;
102 
103 	/* wm9713 irq reg */
104 	if (reg == 0x5a)
105 		wm->misc = val;
106 
107 	if (wm->ac97)
108 		wm->ac97->bus->ops->write(wm->ac97, reg, val);
109 }
110 EXPORT_SYMBOL_GPL(wm97xx_reg_write);
111 
112 /**
113  * wm97xx_read_aux_adc - Read the aux adc.
114  * @wm: wm97xx device.
115  * @adcsel: codec ADC to be read
116  *
117  * Reads the selected AUX ADC.
118  */
119 
120 int wm97xx_read_aux_adc(struct wm97xx *wm, u16 adcsel)
121 {
122 	int power_adc = 0, auxval;
123 	u16 power = 0;
124 	int rc = 0;
125 	int timeout = 0;
126 
127 	/* get codec */
128 	mutex_lock(&wm->codec_mutex);
129 
130 	/* When the touchscreen is not in use, we may have to power up
131 	 * the AUX ADC before we can use sample the AUX inputs->
132 	 */
133 	if (wm->id == WM9713_ID2 &&
134 	    (power = wm97xx_reg_read(wm, AC97_EXTENDED_MID)) & 0x8000) {
135 		power_adc = 1;
136 		wm97xx_reg_write(wm, AC97_EXTENDED_MID, power & 0x7fff);
137 	}
138 
139 	/* Prepare the codec for AUX reading */
140 	wm->codec->aux_prepare(wm);
141 
142 	/* Turn polling mode on to read AUX ADC */
143 	wm->pen_probably_down = 1;
144 
145 	while (rc != RC_VALID && timeout++ < 5)
146 		rc = wm->codec->poll_sample(wm, adcsel, &auxval);
147 
148 	if (power_adc)
149 		wm97xx_reg_write(wm, AC97_EXTENDED_MID, power | 0x8000);
150 
151 	wm->codec->dig_restore(wm);
152 
153 	wm->pen_probably_down = 0;
154 
155 	if (timeout >= 5) {
156 		dev_err(wm->dev,
157 			"timeout reading auxadc %d, disabling digitiser\n",
158 			adcsel);
159 		wm->codec->dig_enable(wm, false);
160 	}
161 
162 	mutex_unlock(&wm->codec_mutex);
163 	return (rc == RC_VALID ? auxval & 0xfff : -EBUSY);
164 }
165 EXPORT_SYMBOL_GPL(wm97xx_read_aux_adc);
166 
167 /**
168  * wm97xx_get_gpio - Get the status of a codec GPIO.
169  * @wm: wm97xx device.
170  * @gpio: gpio
171  *
172  * Get the status of a codec GPIO pin
173  */
174 
175 enum wm97xx_gpio_status wm97xx_get_gpio(struct wm97xx *wm, u32 gpio)
176 {
177 	u16 status;
178 	enum wm97xx_gpio_status ret;
179 
180 	mutex_lock(&wm->codec_mutex);
181 	status = wm97xx_reg_read(wm, AC97_GPIO_STATUS);
182 
183 	if (status & gpio)
184 		ret = WM97XX_GPIO_HIGH;
185 	else
186 		ret = WM97XX_GPIO_LOW;
187 
188 	mutex_unlock(&wm->codec_mutex);
189 	return ret;
190 }
191 EXPORT_SYMBOL_GPL(wm97xx_get_gpio);
192 
193 /**
194  * wm97xx_set_gpio - Set the status of a codec GPIO.
195  * @wm: wm97xx device.
196  * @gpio: gpio
197  * @status: status
198  *
199  * Set the status of a codec GPIO pin
200  */
201 
202 void wm97xx_set_gpio(struct wm97xx *wm, u32 gpio,
203 				enum wm97xx_gpio_status status)
204 {
205 	u16 reg;
206 
207 	mutex_lock(&wm->codec_mutex);
208 	reg = wm97xx_reg_read(wm, AC97_GPIO_STATUS);
209 
210 	if (status == WM97XX_GPIO_HIGH)
211 		reg |= gpio;
212 	else
213 		reg &= ~gpio;
214 
215 	if (wm->id == WM9712_ID2 && wm->variant != WM97xx_WM1613)
216 		wm97xx_reg_write(wm, AC97_GPIO_STATUS, reg << 1);
217 	else
218 		wm97xx_reg_write(wm, AC97_GPIO_STATUS, reg);
219 	mutex_unlock(&wm->codec_mutex);
220 }
221 EXPORT_SYMBOL_GPL(wm97xx_set_gpio);
222 
223 /*
224  * Codec GPIO pin configuration, this sets pin direction, polarity,
225  * stickyness and wake up.
226  */
227 void wm97xx_config_gpio(struct wm97xx *wm, u32 gpio, enum wm97xx_gpio_dir dir,
228 		   enum wm97xx_gpio_pol pol, enum wm97xx_gpio_sticky sticky,
229 		   enum wm97xx_gpio_wake wake)
230 {
231 	u16 reg;
232 
233 	mutex_lock(&wm->codec_mutex);
234 	reg = wm97xx_reg_read(wm, AC97_GPIO_POLARITY);
235 
236 	if (pol == WM97XX_GPIO_POL_HIGH)
237 		reg |= gpio;
238 	else
239 		reg &= ~gpio;
240 
241 	wm97xx_reg_write(wm, AC97_GPIO_POLARITY, reg);
242 	reg = wm97xx_reg_read(wm, AC97_GPIO_STICKY);
243 
244 	if (sticky == WM97XX_GPIO_STICKY)
245 		reg |= gpio;
246 	else
247 		reg &= ~gpio;
248 
249 	wm97xx_reg_write(wm, AC97_GPIO_STICKY, reg);
250 	reg = wm97xx_reg_read(wm, AC97_GPIO_WAKEUP);
251 
252 	if (wake == WM97XX_GPIO_WAKE)
253 		reg |= gpio;
254 	else
255 		reg &= ~gpio;
256 
257 	wm97xx_reg_write(wm, AC97_GPIO_WAKEUP, reg);
258 	reg = wm97xx_reg_read(wm, AC97_GPIO_CFG);
259 
260 	if (dir == WM97XX_GPIO_IN)
261 		reg |= gpio;
262 	else
263 		reg &= ~gpio;
264 
265 	wm97xx_reg_write(wm, AC97_GPIO_CFG, reg);
266 	mutex_unlock(&wm->codec_mutex);
267 }
268 EXPORT_SYMBOL_GPL(wm97xx_config_gpio);
269 
270 /*
271  * Configure the WM97XX_PRP value to use while system is suspended.
272  * If a value other than 0 is set then WM97xx pen detection will be
273  * left enabled in the configured mode while the system is in suspend,
274  * the device has users and suspend has not been disabled via the
275  * wakeup sysfs entries.
276  *
277  * @wm:   WM97xx device to configure
278  * @mode: WM97XX_PRP value to configure while suspended
279  */
280 void wm97xx_set_suspend_mode(struct wm97xx *wm, u16 mode)
281 {
282 	wm->suspend_mode = mode;
283 	device_init_wakeup(&wm->input_dev->dev, mode != 0);
284 }
285 EXPORT_SYMBOL_GPL(wm97xx_set_suspend_mode);
286 
287 /*
288  * Codec PENDOWN irq handler
289  *
290  */
291 static irqreturn_t wm97xx_pen_interrupt(int irq, void *dev_id)
292 {
293 	struct wm97xx *wm = dev_id;
294 	int pen_was_down = wm->pen_is_down;
295 
296 	/* do we need to enable the touch panel reader */
297 	if (wm->id == WM9705_ID2) {
298 		if (wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD) &
299 					WM97XX_PEN_DOWN)
300 			wm->pen_is_down = 1;
301 		else
302 			wm->pen_is_down = 0;
303 	} else {
304 		u16 status, pol;
305 		mutex_lock(&wm->codec_mutex);
306 		status = wm97xx_reg_read(wm, AC97_GPIO_STATUS);
307 		pol = wm97xx_reg_read(wm, AC97_GPIO_POLARITY);
308 
309 		if (WM97XX_GPIO_13 & pol & status) {
310 			wm->pen_is_down = 1;
311 			wm97xx_reg_write(wm, AC97_GPIO_POLARITY, pol &
312 						~WM97XX_GPIO_13);
313 		} else {
314 			wm->pen_is_down = 0;
315 			wm97xx_reg_write(wm, AC97_GPIO_POLARITY, pol |
316 					 WM97XX_GPIO_13);
317 		}
318 
319 		if (wm->id == WM9712_ID2 && wm->variant != WM97xx_WM1613)
320 			wm97xx_reg_write(wm, AC97_GPIO_STATUS, (status &
321 						~WM97XX_GPIO_13) << 1);
322 		else
323 			wm97xx_reg_write(wm, AC97_GPIO_STATUS, status &
324 						~WM97XX_GPIO_13);
325 		mutex_unlock(&wm->codec_mutex);
326 	}
327 
328 	/* If the system is not using continuous mode or it provides a
329 	 * pen down operation then we need to schedule polls while the
330 	 * pen is down.  Otherwise the machine driver is responsible
331 	 * for scheduling reads.
332 	 */
333 	if (!wm->mach_ops->acc_enabled || wm->mach_ops->acc_pen_down) {
334 		if (wm->pen_is_down && !pen_was_down) {
335 			/* Data is not available immediately on pen down */
336 			queue_delayed_work(wm->ts_workq, &wm->ts_reader, 1);
337 		}
338 
339 		/* Let ts_reader report the pen up for debounce. */
340 		if (!wm->pen_is_down && pen_was_down)
341 			wm->pen_is_down = 1;
342 	}
343 
344 	if (!wm->pen_is_down && wm->mach_ops->acc_enabled)
345 		wm->mach_ops->acc_pen_up(wm);
346 
347 	return IRQ_HANDLED;
348 }
349 
350 /*
351  * initialise pen IRQ handler and workqueue
352  */
353 static int wm97xx_init_pen_irq(struct wm97xx *wm)
354 {
355 	u16 reg;
356 
357 	if (request_threaded_irq(wm->pen_irq, NULL, wm97xx_pen_interrupt,
358 				 IRQF_SHARED | IRQF_ONESHOT,
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_report_key(wm->input_dev, BTN_TOUCH, 0);
397 			input_sync(wm->input_dev);
398 		} else if (!(rc & RC_AGAIN)) {
399 			/* We need high frequency updates only while
400 			* pen is down, the user never will be able to
401 			* touch screen faster than a few times per
402 			* second... On the other hand, when the user
403 			* is actively working with the touchscreen we
404 			* don't want to lose the quick response. So we
405 			* will slowly increase sleep time after the
406 			* pen is up and quicky restore it to ~one task
407 			* switch when pen is down again.
408 			*/
409 			if (wm->ts_reader_interval < HZ / 10)
410 				wm->ts_reader_interval++;
411 		}
412 
413 	} else if (rc & RC_VALID) {
414 		dev_dbg(wm->dev,
415 			"pen down: x=%x:%d, y=%x:%d, pressure=%x:%d\n",
416 			data.x >> 12, data.x & 0xfff, data.y >> 12,
417 			data.y & 0xfff, data.p >> 12, data.p & 0xfff);
418 
419 		if (abs_x[0] > (data.x & 0xfff) ||
420 		    abs_x[1] < (data.x & 0xfff) ||
421 		    abs_y[0] > (data.y & 0xfff) ||
422 		    abs_y[1] < (data.y & 0xfff)) {
423 			dev_dbg(wm->dev, "Measurement out of range, dropping it\n");
424 			rc = RC_AGAIN;
425 			goto out;
426 		}
427 
428 		input_report_abs(wm->input_dev, ABS_X, data.x & 0xfff);
429 		input_report_abs(wm->input_dev, ABS_Y, data.y & 0xfff);
430 		input_report_abs(wm->input_dev, ABS_PRESSURE, data.p & 0xfff);
431 		input_report_key(wm->input_dev, BTN_TOUCH, 1);
432 		input_sync(wm->input_dev);
433 		wm->pen_is_down = 1;
434 		wm->ts_reader_interval = wm->ts_reader_min_interval;
435 	} else if (rc & RC_PENDOWN) {
436 		dev_dbg(wm->dev, "pen down\n");
437 		wm->pen_is_down = 1;
438 		wm->ts_reader_interval = wm->ts_reader_min_interval;
439 	}
440 
441 out:
442 	mutex_unlock(&wm->codec_mutex);
443 	return rc;
444 }
445 
446 /*
447 * The touchscreen sample reader.
448 */
449 static void wm97xx_ts_reader(struct work_struct *work)
450 {
451 	int rc;
452 	struct wm97xx *wm = container_of(work, struct wm97xx, ts_reader.work);
453 
454 	BUG_ON(!wm->codec);
455 
456 	do {
457 		rc = wm97xx_read_samples(wm);
458 	} while (rc & RC_AGAIN);
459 
460 	if (wm->pen_is_down || !wm->pen_irq)
461 		queue_delayed_work(wm->ts_workq, &wm->ts_reader,
462 				   wm->ts_reader_interval);
463 }
464 
465 /**
466  * wm97xx_ts_input_open - Open the touch screen input device.
467  * @idev:	Input device to be opened.
468  *
469  * Called by the input sub system to open a wm97xx touchscreen device.
470  * Starts the touchscreen thread and touch digitiser.
471  */
472 static int wm97xx_ts_input_open(struct input_dev *idev)
473 {
474 	struct wm97xx *wm = input_get_drvdata(idev);
475 
476 	wm->ts_workq = alloc_ordered_workqueue("kwm97xx", 0);
477 	if (wm->ts_workq == NULL) {
478 		dev_err(wm->dev,
479 			"Failed to create workqueue\n");
480 		return -EINVAL;
481 	}
482 
483 	/* start digitiser */
484 	if (wm->mach_ops && wm->mach_ops->acc_enabled)
485 		wm->codec->acc_enable(wm, 1);
486 	wm->codec->dig_enable(wm, 1);
487 
488 	INIT_DELAYED_WORK(&wm->ts_reader, wm97xx_ts_reader);
489 
490 	wm->ts_reader_min_interval = HZ >= 100 ? HZ / 100 : 1;
491 	if (wm->ts_reader_min_interval < 1)
492 		wm->ts_reader_min_interval = 1;
493 	wm->ts_reader_interval = wm->ts_reader_min_interval;
494 
495 	wm->pen_is_down = 0;
496 	if (wm->pen_irq)
497 		wm97xx_init_pen_irq(wm);
498 	else
499 		dev_err(wm->dev, "No IRQ specified\n");
500 
501 	/* If we either don't have an interrupt for pen down events or
502 	 * failed to acquire it then we need to poll.
503 	 */
504 	if (wm->pen_irq == 0)
505 		queue_delayed_work(wm->ts_workq, &wm->ts_reader,
506 				   wm->ts_reader_interval);
507 
508 	return 0;
509 }
510 
511 /**
512  * wm97xx_ts_input_close - Close the touch screen input device.
513  * @idev:	Input device to be closed.
514  *
515  * Called by the input sub system to close a wm97xx touchscreen
516  * device.  Kills the touchscreen thread and stops the touch
517  * digitiser.
518  */
519 
520 static void wm97xx_ts_input_close(struct input_dev *idev)
521 {
522 	struct wm97xx *wm = input_get_drvdata(idev);
523 	u16 reg;
524 
525 	if (wm->pen_irq) {
526 		/* Return the interrupt to GPIO usage (disabling it) */
527 		if (wm->id != WM9705_ID2) {
528 			BUG_ON(!wm->mach_ops->irq_gpio);
529 			reg = wm97xx_reg_read(wm, AC97_MISC_AFE);
530 			wm97xx_reg_write(wm, AC97_MISC_AFE,
531 					 reg | wm->mach_ops->irq_gpio);
532 		}
533 
534 		free_irq(wm->pen_irq, wm);
535 	}
536 
537 	wm->pen_is_down = 0;
538 
539 	/* ts_reader rearms itself so we need to explicitly stop it
540 	 * before we destroy the workqueue.
541 	 */
542 	cancel_delayed_work_sync(&wm->ts_reader);
543 
544 	destroy_workqueue(wm->ts_workq);
545 
546 	/* stop digitiser */
547 	wm->codec->dig_enable(wm, 0);
548 	if (wm->mach_ops && wm->mach_ops->acc_enabled)
549 		wm->codec->acc_enable(wm, 0);
550 }
551 
552 static int wm97xx_register_touch(struct wm97xx *wm)
553 {
554 	struct wm97xx_pdata *pdata = dev_get_platdata(wm->dev);
555 	int ret;
556 
557 	wm->input_dev = devm_input_allocate_device(wm->dev);
558 	if (wm->input_dev == NULL)
559 		return -ENOMEM;
560 
561 	/* set up touch configuration */
562 	wm->input_dev->name = "wm97xx touchscreen";
563 	wm->input_dev->phys = "wm97xx";
564 	wm->input_dev->open = wm97xx_ts_input_open;
565 	wm->input_dev->close = wm97xx_ts_input_close;
566 
567 	__set_bit(EV_ABS, wm->input_dev->evbit);
568 	__set_bit(EV_KEY, wm->input_dev->evbit);
569 	__set_bit(BTN_TOUCH, wm->input_dev->keybit);
570 
571 	input_set_abs_params(wm->input_dev, ABS_X, abs_x[0], abs_x[1],
572 			     abs_x[2], 0);
573 	input_set_abs_params(wm->input_dev, ABS_Y, abs_y[0], abs_y[1],
574 			     abs_y[2], 0);
575 	input_set_abs_params(wm->input_dev, ABS_PRESSURE, abs_p[0], abs_p[1],
576 			     abs_p[2], 0);
577 
578 	input_set_drvdata(wm->input_dev, wm);
579 	wm->input_dev->dev.parent = wm->dev;
580 
581 	ret = input_register_device(wm->input_dev);
582 	if (ret)
583 		return ret;
584 
585 	/*
586 	 * register our extended touch device (for machine specific
587 	 * extensions)
588 	 */
589 	wm->touch_dev = platform_device_alloc("wm97xx-touch", -1);
590 	if (!wm->touch_dev)
591 		return -ENOMEM;
592 
593 	platform_set_drvdata(wm->touch_dev, wm);
594 	wm->touch_dev->dev.parent = wm->dev;
595 	wm->touch_dev->dev.platform_data = pdata;
596 	ret = platform_device_add(wm->touch_dev);
597 	if (ret < 0)
598 		goto touch_reg_err;
599 
600 	return 0;
601 touch_reg_err:
602 	platform_device_put(wm->touch_dev);
603 
604 	return ret;
605 }
606 
607 static void wm97xx_unregister_touch(struct wm97xx *wm)
608 {
609 	platform_device_unregister(wm->touch_dev);
610 }
611 
612 static int _wm97xx_probe(struct wm97xx *wm)
613 {
614 	int id = 0;
615 
616 	mutex_init(&wm->codec_mutex);
617 	dev_set_drvdata(wm->dev, wm);
618 
619 	/* check that we have a supported codec */
620 	id = wm97xx_reg_read(wm, AC97_VENDOR_ID1);
621 	if (id != WM97XX_ID1) {
622 		dev_err(wm->dev,
623 			"Device with vendor %04x is not a wm97xx\n", id);
624 		return -ENODEV;
625 	}
626 
627 	wm->id = wm97xx_reg_read(wm, AC97_VENDOR_ID2);
628 
629 	wm->variant = WM97xx_GENERIC;
630 
631 	dev_info(wm->dev, "detected a wm97%02x codec\n", wm->id & 0xff);
632 
633 	switch (wm->id & 0xff) {
634 #ifdef CONFIG_TOUCHSCREEN_WM9705
635 	case 0x05:
636 		wm->codec = &wm9705_codec;
637 		break;
638 #endif
639 #ifdef CONFIG_TOUCHSCREEN_WM9712
640 	case 0x12:
641 		wm->codec = &wm9712_codec;
642 		break;
643 #endif
644 #ifdef CONFIG_TOUCHSCREEN_WM9713
645 	case 0x13:
646 		wm->codec = &wm9713_codec;
647 		break;
648 #endif
649 	default:
650 		dev_err(wm->dev, "Support for wm97%02x not compiled in.\n",
651 			wm->id & 0xff);
652 		return -ENODEV;
653 	}
654 
655 	/* set up physical characteristics */
656 	wm->codec->phy_init(wm);
657 
658 	/* load gpio cache */
659 	wm->gpio[0] = wm97xx_reg_read(wm, AC97_GPIO_CFG);
660 	wm->gpio[1] = wm97xx_reg_read(wm, AC97_GPIO_POLARITY);
661 	wm->gpio[2] = wm97xx_reg_read(wm, AC97_GPIO_STICKY);
662 	wm->gpio[3] = wm97xx_reg_read(wm, AC97_GPIO_WAKEUP);
663 	wm->gpio[4] = wm97xx_reg_read(wm, AC97_GPIO_STATUS);
664 	wm->gpio[5] = wm97xx_reg_read(wm, AC97_MISC_AFE);
665 
666 	return wm97xx_register_touch(wm);
667 }
668 
669 static void wm97xx_remove_battery(struct wm97xx *wm)
670 {
671 	platform_device_unregister(wm->battery_dev);
672 }
673 
674 static int wm97xx_add_battery(struct wm97xx *wm,
675 			      struct wm97xx_batt_pdata *pdata)
676 {
677 	int ret;
678 
679 	wm->battery_dev = platform_device_alloc("wm97xx-battery", -1);
680 	if (!wm->battery_dev)
681 		return -ENOMEM;
682 
683 	platform_set_drvdata(wm->battery_dev, wm);
684 	wm->battery_dev->dev.parent = wm->dev;
685 	wm->battery_dev->dev.platform_data = pdata;
686 	ret = platform_device_add(wm->battery_dev);
687 	if (ret)
688 		platform_device_put(wm->battery_dev);
689 
690 	return ret;
691 }
692 
693 static int wm97xx_probe(struct device *dev)
694 {
695 	struct wm97xx *wm;
696 	int ret;
697 	struct wm97xx_pdata *pdata = dev_get_platdata(dev);
698 
699 	wm = devm_kzalloc(dev, sizeof(struct wm97xx), GFP_KERNEL);
700 	if (!wm)
701 		return -ENOMEM;
702 
703 	wm->dev = dev;
704 	wm->ac97 = to_ac97_t(dev);
705 
706 	ret =  _wm97xx_probe(wm);
707 	if (ret)
708 		return ret;
709 
710 	ret = wm97xx_add_battery(wm, pdata ? pdata->batt_pdata : NULL);
711 	if (ret < 0)
712 		goto batt_err;
713 
714 	return ret;
715 
716 batt_err:
717 	wm97xx_unregister_touch(wm);
718 	return ret;
719 }
720 
721 static int wm97xx_remove(struct device *dev)
722 {
723 	struct wm97xx *wm = dev_get_drvdata(dev);
724 
725 	wm97xx_remove_battery(wm);
726 	wm97xx_unregister_touch(wm);
727 
728 	return 0;
729 }
730 
731 static int wm97xx_mfd_probe(struct platform_device *pdev)
732 {
733 	struct wm97xx *wm;
734 	struct wm97xx_platform_data *mfd_pdata = dev_get_platdata(&pdev->dev);
735 	int ret;
736 
737 	wm = devm_kzalloc(&pdev->dev, sizeof(struct wm97xx), GFP_KERNEL);
738 	if (!wm)
739 		return -ENOMEM;
740 
741 	wm->dev = &pdev->dev;
742 	wm->ac97 = mfd_pdata->ac97;
743 
744 	ret =  _wm97xx_probe(wm);
745 	if (ret)
746 		return ret;
747 
748 	ret = wm97xx_add_battery(wm, mfd_pdata->batt_pdata);
749 	if (ret < 0)
750 		goto batt_err;
751 
752 	return ret;
753 
754 batt_err:
755 	wm97xx_unregister_touch(wm);
756 	return ret;
757 }
758 
759 static int wm97xx_mfd_remove(struct platform_device *pdev)
760 {
761 	wm97xx_remove(&pdev->dev);
762 
763 	return 0;
764 }
765 
766 static int __maybe_unused wm97xx_suspend(struct device *dev)
767 {
768 	struct wm97xx *wm = dev_get_drvdata(dev);
769 	u16 reg;
770 	int suspend_mode;
771 
772 	if (device_may_wakeup(&wm->input_dev->dev))
773 		suspend_mode = wm->suspend_mode;
774 	else
775 		suspend_mode = 0;
776 
777 	mutex_lock(&wm->input_dev->mutex);
778 	if (input_device_enabled(wm->input_dev))
779 		cancel_delayed_work_sync(&wm->ts_reader);
780 
781 	/* Power down the digitiser (bypassing the cache for resume) */
782 	reg = wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER2);
783 	reg &= ~WM97XX_PRP_DET_DIG;
784 	if (input_device_enabled(wm->input_dev))
785 		reg |= suspend_mode;
786 	wm->ac97->bus->ops->write(wm->ac97, AC97_WM97XX_DIGITISER2, reg);
787 
788 	/* WM9713 has an additional power bit - turn it off if there
789 	 * are no users or if suspend mode is zero. */
790 	if (wm->id == WM9713_ID2 &&
791 	    (!input_device_enabled(wm->input_dev) || !suspend_mode)) {
792 		reg = wm97xx_reg_read(wm, AC97_EXTENDED_MID) | 0x8000;
793 		wm97xx_reg_write(wm, AC97_EXTENDED_MID, reg);
794 	}
795 	mutex_unlock(&wm->input_dev->mutex);
796 
797 	return 0;
798 }
799 
800 static int __maybe_unused wm97xx_resume(struct device *dev)
801 {
802 	struct wm97xx *wm = dev_get_drvdata(dev);
803 
804 	mutex_lock(&wm->input_dev->mutex);
805 	/* restore digitiser and gpios */
806 	if (wm->id == WM9713_ID2) {
807 		wm97xx_reg_write(wm, AC97_WM9713_DIG1, wm->dig[0]);
808 		wm97xx_reg_write(wm, 0x5a, wm->misc);
809 		if (input_device_enabled(wm->input_dev)) {
810 			u16 reg;
811 			reg = wm97xx_reg_read(wm, AC97_EXTENDED_MID) & 0x7fff;
812 			wm97xx_reg_write(wm, AC97_EXTENDED_MID, reg);
813 		}
814 	}
815 
816 	wm97xx_reg_write(wm, AC97_WM9713_DIG2, wm->dig[1]);
817 	wm97xx_reg_write(wm, AC97_WM9713_DIG3, wm->dig[2]);
818 
819 	wm97xx_reg_write(wm, AC97_GPIO_CFG, wm->gpio[0]);
820 	wm97xx_reg_write(wm, AC97_GPIO_POLARITY, wm->gpio[1]);
821 	wm97xx_reg_write(wm, AC97_GPIO_STICKY, wm->gpio[2]);
822 	wm97xx_reg_write(wm, AC97_GPIO_WAKEUP, wm->gpio[3]);
823 	wm97xx_reg_write(wm, AC97_GPIO_STATUS, wm->gpio[4]);
824 	wm97xx_reg_write(wm, AC97_MISC_AFE, wm->gpio[5]);
825 
826 	if (input_device_enabled(wm->input_dev) && !wm->pen_irq) {
827 		wm->ts_reader_interval = wm->ts_reader_min_interval;
828 		queue_delayed_work(wm->ts_workq, &wm->ts_reader,
829 				   wm->ts_reader_interval);
830 	}
831 	mutex_unlock(&wm->input_dev->mutex);
832 
833 	return 0;
834 }
835 
836 static SIMPLE_DEV_PM_OPS(wm97xx_pm_ops, wm97xx_suspend, wm97xx_resume);
837 
838 /*
839  * Machine specific operations
840  */
841 int wm97xx_register_mach_ops(struct wm97xx *wm,
842 			     struct wm97xx_mach_ops *mach_ops)
843 {
844 	mutex_lock(&wm->codec_mutex);
845 	if (wm->mach_ops) {
846 		mutex_unlock(&wm->codec_mutex);
847 		return -EINVAL;
848 	}
849 	wm->mach_ops = mach_ops;
850 	mutex_unlock(&wm->codec_mutex);
851 
852 	return 0;
853 }
854 EXPORT_SYMBOL_GPL(wm97xx_register_mach_ops);
855 
856 void wm97xx_unregister_mach_ops(struct wm97xx *wm)
857 {
858 	mutex_lock(&wm->codec_mutex);
859 	wm->mach_ops = NULL;
860 	mutex_unlock(&wm->codec_mutex);
861 }
862 EXPORT_SYMBOL_GPL(wm97xx_unregister_mach_ops);
863 
864 static struct device_driver wm97xx_driver = {
865 	.name =		"wm97xx-ts",
866 #ifdef CONFIG_AC97_BUS
867 	.bus =		&ac97_bus_type,
868 #endif
869 	.owner =	THIS_MODULE,
870 	.probe =	wm97xx_probe,
871 	.remove =	wm97xx_remove,
872 	.pm =		&wm97xx_pm_ops,
873 };
874 
875 static struct platform_driver wm97xx_mfd_driver = {
876 	.driver = {
877 		.name =		"wm97xx-ts",
878 		.pm =		&wm97xx_pm_ops,
879 	},
880 	.probe =	wm97xx_mfd_probe,
881 	.remove =	wm97xx_mfd_remove,
882 };
883 
884 static int __init wm97xx_init(void)
885 {
886 	int ret;
887 
888 	ret = platform_driver_register(&wm97xx_mfd_driver);
889 	if (ret)
890 		return ret;
891 
892 	if (IS_BUILTIN(CONFIG_AC97_BUS))
893 		ret =  driver_register(&wm97xx_driver);
894 	return ret;
895 }
896 
897 static void __exit wm97xx_exit(void)
898 {
899 	if (IS_BUILTIN(CONFIG_AC97_BUS))
900 		driver_unregister(&wm97xx_driver);
901 	platform_driver_unregister(&wm97xx_mfd_driver);
902 }
903 
904 module_init(wm97xx_init);
905 module_exit(wm97xx_exit);
906 
907 /* Module information */
908 MODULE_AUTHOR("Liam Girdwood <lrg@slimlogic.co.uk>");
909 MODULE_DESCRIPTION("WM97xx Core - Touch Screen / AUX ADC / GPIO Driver");
910 MODULE_LICENSE("GPL");
911