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1/*
2 * Copyright (C) 2006-2008 Michael Hennerich, Analog Devices Inc.
3 *
4 * Description:	AD7877 based touchscreen, sensor (ADCs), DAC and GPIO driver
5 * Based on:	ads7846.c
6 *
7 * Bugs:        Enter bugs at http://blackfin.uclinux.org/
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, see the file COPYING, or write
21 * to the Free Software Foundation, Inc.,
22 * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
23 *
24 * History:
25 * Copyright (c) 2005 David Brownell
26 * Copyright (c) 2006 Nokia Corporation
27 * Various changes: Imre Deak <imre.deak@nokia.com>
28 *
29 * Using code from:
30 *  - corgi_ts.c
31 *	Copyright (C) 2004-2005 Richard Purdie
32 *  - omap_ts.[hc], ads7846.h, ts_osk.c
33 *	Copyright (C) 2002 MontaVista Software
34 *	Copyright (C) 2004 Texas Instruments
35 *	Copyright (C) 2005 Dirk Behme
36 */
37
38
39#include <linux/device.h>
40#include <linux/init.h>
41#include <linux/delay.h>
42#include <linux/input.h>
43#include <linux/interrupt.h>
44#include <linux/slab.h>
45#include <linux/spi/spi.h>
46#include <linux/spi/ad7877.h>
47#include <asm/irq.h>
48
49#define	TS_PEN_UP_TIMEOUT	msecs_to_jiffies(100)
50
51#define MAX_SPI_FREQ_HZ			20000000
52#define	MAX_12BIT			((1<<12)-1)
53
54#define AD7877_REG_ZEROS			0
55#define AD7877_REG_CTRL1			1
56#define AD7877_REG_CTRL2			2
57#define AD7877_REG_ALERT			3
58#define AD7877_REG_AUX1HIGH			4
59#define AD7877_REG_AUX1LOW			5
60#define AD7877_REG_BAT1HIGH			6
61#define AD7877_REG_BAT1LOW			7
62#define AD7877_REG_BAT2HIGH			8
63#define AD7877_REG_BAT2LOW			9
64#define AD7877_REG_TEMP1HIGH			10
65#define AD7877_REG_TEMP1LOW			11
66#define AD7877_REG_SEQ0				12
67#define AD7877_REG_SEQ1				13
68#define AD7877_REG_DAC				14
69#define AD7877_REG_NONE1			15
70#define AD7877_REG_EXTWRITE			15
71#define AD7877_REG_XPLUS			16
72#define AD7877_REG_YPLUS			17
73#define AD7877_REG_Z2				18
74#define AD7877_REG_aux1				19
75#define AD7877_REG_aux2				20
76#define AD7877_REG_aux3				21
77#define AD7877_REG_bat1				22
78#define AD7877_REG_bat2				23
79#define AD7877_REG_temp1			24
80#define AD7877_REG_temp2			25
81#define AD7877_REG_Z1				26
82#define AD7877_REG_GPIOCTRL1			27
83#define AD7877_REG_GPIOCTRL2			28
84#define AD7877_REG_GPIODATA			29
85#define AD7877_REG_NONE2			30
86#define AD7877_REG_NONE3			31
87
88#define AD7877_SEQ_YPLUS_BIT			(1<<11)
89#define AD7877_SEQ_XPLUS_BIT			(1<<10)
90#define AD7877_SEQ_Z2_BIT			(1<<9)
91#define AD7877_SEQ_AUX1_BIT			(1<<8)
92#define AD7877_SEQ_AUX2_BIT			(1<<7)
93#define AD7877_SEQ_AUX3_BIT			(1<<6)
94#define AD7877_SEQ_BAT1_BIT			(1<<5)
95#define AD7877_SEQ_BAT2_BIT			(1<<4)
96#define AD7877_SEQ_TEMP1_BIT			(1<<3)
97#define AD7877_SEQ_TEMP2_BIT			(1<<2)
98#define AD7877_SEQ_Z1_BIT			(1<<1)
99
100enum {
101	AD7877_SEQ_YPOS  = 0,
102	AD7877_SEQ_XPOS  = 1,
103	AD7877_SEQ_Z2    = 2,
104	AD7877_SEQ_AUX1  = 3,
105	AD7877_SEQ_AUX2  = 4,
106	AD7877_SEQ_AUX3  = 5,
107	AD7877_SEQ_BAT1  = 6,
108	AD7877_SEQ_BAT2  = 7,
109	AD7877_SEQ_TEMP1 = 8,
110	AD7877_SEQ_TEMP2 = 9,
111	AD7877_SEQ_Z1    = 10,
112	AD7877_NR_SENSE  = 11,
113};
114
115/* DAC Register Default RANGE 0 to Vcc, Volatge Mode, DAC On */
116#define AD7877_DAC_CONF			0x1
117
118/* If gpio3 is set AUX3/GPIO3 acts as GPIO Output */
119#define AD7877_EXTW_GPIO_3_CONF		0x1C4
120#define AD7877_EXTW_GPIO_DATA		0x200
121
122/* Control REG 2 */
123#define AD7877_TMR(x)			((x & 0x3) << 0)
124#define AD7877_REF(x)			((x & 0x1) << 2)
125#define AD7877_POL(x)			((x & 0x1) << 3)
126#define AD7877_FCD(x)			((x & 0x3) << 4)
127#define AD7877_PM(x)			((x & 0x3) << 6)
128#define AD7877_ACQ(x)			((x & 0x3) << 8)
129#define AD7877_AVG(x)			((x & 0x3) << 10)
130
131/* Control REG 1 */
132#define	AD7877_SER			(1 << 11)	/* non-differential */
133#define	AD7877_DFR			(0 << 11)	/* differential */
134
135#define AD7877_MODE_NOC  (0)	/* Do not convert */
136#define AD7877_MODE_SCC  (1)	/* Single channel conversion */
137#define AD7877_MODE_SEQ0 (2)	/* Sequence 0 in Slave Mode */
138#define AD7877_MODE_SEQ1 (3)	/* Sequence 1 in Master Mode */
139
140#define AD7877_CHANADD(x)		((x&0xF)<<7)
141#define AD7877_READADD(x)		((x)<<2)
142#define AD7877_WRITEADD(x)		((x)<<12)
143
144#define AD7877_READ_CHAN(x) (AD7877_WRITEADD(AD7877_REG_CTRL1) | AD7877_SER | \
145		AD7877_MODE_SCC | AD7877_CHANADD(AD7877_REG_ ## x) | \
146		AD7877_READADD(AD7877_REG_ ## x))
147
148#define AD7877_MM_SEQUENCE (AD7877_SEQ_YPLUS_BIT | AD7877_SEQ_XPLUS_BIT | \
149		AD7877_SEQ_Z2_BIT | AD7877_SEQ_Z1_BIT)
150
151/*
152 * Non-touchscreen sensors only use single-ended conversions.
153 */
154
155struct ser_req {
156	u16			reset;
157	u16			ref_on;
158	u16			command;
159	struct spi_message	msg;
160	struct spi_transfer	xfer[6];
161
162	/*
163	 * DMA (thus cache coherency maintenance) requires the
164	 * transfer buffers to live in their own cache lines.
165	 */
166	u16 sample ____cacheline_aligned;
167};
168
169struct ad7877 {
170	struct input_dev	*input;
171	char			phys[32];
172
173	struct spi_device	*spi;
174	u16			model;
175	u16			vref_delay_usecs;
176	u16			x_plate_ohms;
177	u16			pressure_max;
178
179	u16			cmd_crtl1;
180	u16			cmd_crtl2;
181	u16			cmd_dummy;
182	u16			dac;
183
184	u8			stopacq_polarity;
185	u8			first_conversion_delay;
186	u8			acquisition_time;
187	u8			averaging;
188	u8			pen_down_acc_interval;
189
190	struct spi_transfer	xfer[AD7877_NR_SENSE + 2];
191	struct spi_message	msg;
192
193	struct mutex		mutex;
194	unsigned		disabled:1;	/* P: mutex */
195	unsigned		gpio3:1;	/* P: mutex */
196	unsigned		gpio4:1;	/* P: mutex */
197
198	spinlock_t		lock;
199	struct timer_list	timer;		/* P: lock */
200	unsigned		pending:1;	/* P: lock */
201
202	/*
203	 * DMA (thus cache coherency maintenance) requires the
204	 * transfer buffers to live in their own cache lines.
205	 */
206	u16 conversion_data[AD7877_NR_SENSE] ____cacheline_aligned;
207};
208
209static int gpio3;
210module_param(gpio3, int, 0);
211MODULE_PARM_DESC(gpio3, "If gpio3 is set to 1 AUX3 acts as GPIO3");
212
213/*
214 * ad7877_read/write are only used for initial setup and for sysfs controls.
215 * The main traffic is done using spi_async() in the interrupt handler.
216 */
217
218static int ad7877_read(struct spi_device *spi, u16 reg)
219{
220	struct ser_req *req;
221	int status, ret;
222
223	req = kzalloc(sizeof *req, GFP_KERNEL);
224	if (!req)
225		return -ENOMEM;
226
227	spi_message_init(&req->msg);
228
229	req->command = (u16) (AD7877_WRITEADD(AD7877_REG_CTRL1) |
230			AD7877_READADD(reg));
231	req->xfer[0].tx_buf = &req->command;
232	req->xfer[0].len = 2;
233
234	req->xfer[1].rx_buf = &req->sample;
235	req->xfer[1].len = 2;
236
237	spi_message_add_tail(&req->xfer[0], &req->msg);
238	spi_message_add_tail(&req->xfer[1], &req->msg);
239
240	status = spi_sync(spi, &req->msg);
241	ret = status ? : req->sample;
242
243	kfree(req);
244
245	return ret;
246}
247
248static int ad7877_write(struct spi_device *spi, u16 reg, u16 val)
249{
250	struct ser_req *req;
251	int status;
252
253	req = kzalloc(sizeof *req, GFP_KERNEL);
254	if (!req)
255		return -ENOMEM;
256
257	spi_message_init(&req->msg);
258
259	req->command = (u16) (AD7877_WRITEADD(reg) | (val & MAX_12BIT));
260	req->xfer[0].tx_buf = &req->command;
261	req->xfer[0].len = 2;
262
263	spi_message_add_tail(&req->xfer[0], &req->msg);
264
265	status = spi_sync(spi, &req->msg);
266
267	kfree(req);
268
269	return status;
270}
271
272static int ad7877_read_adc(struct spi_device *spi, unsigned command)
273{
274	struct ad7877 *ts = dev_get_drvdata(&spi->dev);
275	struct ser_req *req;
276	int status;
277	int sample;
278	int i;
279
280	req = kzalloc(sizeof *req, GFP_KERNEL);
281	if (!req)
282		return -ENOMEM;
283
284	spi_message_init(&req->msg);
285
286	/* activate reference, so it has time to settle; */
287	req->ref_on = AD7877_WRITEADD(AD7877_REG_CTRL2) |
288			 AD7877_POL(ts->stopacq_polarity) |
289			 AD7877_AVG(0) | AD7877_PM(2) | AD7877_TMR(0) |
290			 AD7877_ACQ(ts->acquisition_time) | AD7877_FCD(0);
291
292	req->reset = AD7877_WRITEADD(AD7877_REG_CTRL1) | AD7877_MODE_NOC;
293
294	req->command = (u16) command;
295
296	req->xfer[0].tx_buf = &req->reset;
297	req->xfer[0].len = 2;
298
299	req->xfer[1].tx_buf = &req->ref_on;
300	req->xfer[1].len = 2;
301	req->xfer[1].delay_usecs = ts->vref_delay_usecs;
302
303	req->xfer[2].tx_buf = &req->command;
304	req->xfer[2].len = 2;
305	req->xfer[2].delay_usecs = ts->vref_delay_usecs;
306
307	req->xfer[3].rx_buf = &req->sample;
308	req->xfer[3].len = 2;
309
310	req->xfer[4].tx_buf = &ts->cmd_crtl2;	/*REF OFF*/
311	req->xfer[4].len = 2;
312
313	req->xfer[5].tx_buf = &ts->cmd_crtl1;	/*DEFAULT*/
314	req->xfer[5].len = 2;
315
316	/* group all the transfers together, so we can't interfere with
317	 * reading touchscreen state; disable penirq while sampling
318	 */
319	for (i = 0; i < 6; i++)
320		spi_message_add_tail(&req->xfer[i], &req->msg);
321
322	status = spi_sync(spi, &req->msg);
323	sample = req->sample;
324
325	kfree(req);
326
327	return status ? : sample;
328}
329
330static void ad7877_rx(struct ad7877 *ts)
331{
332	struct input_dev *input_dev = ts->input;
333	unsigned Rt;
334	u16 x, y, z1, z2;
335
336	x = ts->conversion_data[AD7877_SEQ_XPOS] & MAX_12BIT;
337	y = ts->conversion_data[AD7877_SEQ_YPOS] & MAX_12BIT;
338	z1 = ts->conversion_data[AD7877_SEQ_Z1] & MAX_12BIT;
339	z2 = ts->conversion_data[AD7877_SEQ_Z2] & MAX_12BIT;
340
341	/*
342	 * The samples processed here are already preprocessed by the AD7877.
343	 * The preprocessing function consists of an averaging filter.
344	 * The combination of 'first conversion delay' and averaging provides a robust solution,
345	 * discarding the spurious noise in the signal and keeping only the data of interest.
346	 * The size of the averaging filter is programmable. (dev.platform_data, see linux/spi/ad7877.h)
347	 * Other user-programmable conversion controls include variable acquisition time,
348	 * and first conversion delay. Up to 16 averages can be taken per conversion.
349	 */
350
351	if (likely(x && z1)) {
352		/* compute touch pressure resistance using equation #1 */
353		Rt = (z2 - z1) * x * ts->x_plate_ohms;
354		Rt /= z1;
355		Rt = (Rt + 2047) >> 12;
356
357		input_report_abs(input_dev, ABS_X, x);
358		input_report_abs(input_dev, ABS_Y, y);
359		input_report_abs(input_dev, ABS_PRESSURE, Rt);
360		input_sync(input_dev);
361	}
362}
363
364static inline void ad7877_ts_event_release(struct ad7877 *ts)
365{
366	struct input_dev *input_dev = ts->input;
367
368	input_report_abs(input_dev, ABS_PRESSURE, 0);
369	input_sync(input_dev);
370}
371
372static void ad7877_timer(unsigned long handle)
373{
374	struct ad7877 *ts = (void *)handle;
375
376	ad7877_ts_event_release(ts);
377}
378
379static irqreturn_t ad7877_irq(int irq, void *handle)
380{
381	struct ad7877 *ts = handle;
382	unsigned long flags;
383	int status;
384
385	/*
386	 * The repeated conversion sequencer controlled by TMR kicked off
387	 * too fast. We ignore the last and process the sample sequence
388	 * currently in the queue. It can't be older than 9.4ms, and we
389	 * need to avoid that ts->msg doesn't get issued twice while in work.
390	 */
391
392	spin_lock_irqsave(&ts->lock, flags);
393	if (!ts->pending) {
394		ts->pending = 1;
395
396		status = spi_async(ts->spi, &ts->msg);
397		if (status)
398			dev_err(&ts->spi->dev, "spi_sync --> %d\n", status);
399	}
400	spin_unlock_irqrestore(&ts->lock, flags);
401
402	return IRQ_HANDLED;
403}
404
405static void ad7877_callback(void *_ts)
406{
407	struct ad7877 *ts = _ts;
408
409	spin_lock_irq(&ts->lock);
410
411	ad7877_rx(ts);
412	ts->pending = 0;
413	mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
414
415	spin_unlock_irq(&ts->lock);
416}
417
418static void ad7877_disable(struct ad7877 *ts)
419{
420	mutex_lock(&ts->mutex);
421
422	if (!ts->disabled) {
423		ts->disabled = 1;
424		disable_irq(ts->spi->irq);
425
426		/* Wait for spi_async callback */
427		while (ts->pending)
428			msleep(1);
429
430		if (del_timer_sync(&ts->timer))
431			ad7877_ts_event_release(ts);
432	}
433
434	/* we know the chip's in lowpower mode since we always
435	 * leave it that way after every request
436	 */
437
438	mutex_unlock(&ts->mutex);
439}
440
441static void ad7877_enable(struct ad7877 *ts)
442{
443	mutex_lock(&ts->mutex);
444
445	if (ts->disabled) {
446		ts->disabled = 0;
447		enable_irq(ts->spi->irq);
448	}
449
450	mutex_unlock(&ts->mutex);
451}
452
453#define SHOW(name) static ssize_t \
454name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \
455{ \
456	struct ad7877	*ts = dev_get_drvdata(dev); \
457	ssize_t v = ad7877_read_adc(ts->spi, \
458			AD7877_READ_CHAN(name)); \
459	if (v < 0) \
460		return v; \
461	return sprintf(buf, "%u\n", (unsigned) v); \
462} \
463static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
464
465SHOW(aux1)
466SHOW(aux2)
467SHOW(aux3)
468SHOW(bat1)
469SHOW(bat2)
470SHOW(temp1)
471SHOW(temp2)
472
473static ssize_t ad7877_disable_show(struct device *dev,
474				     struct device_attribute *attr, char *buf)
475{
476	struct ad7877	*ts = dev_get_drvdata(dev);
477
478	return sprintf(buf, "%u\n", ts->disabled);
479}
480
481static ssize_t ad7877_disable_store(struct device *dev,
482				     struct device_attribute *attr,
483				     const char *buf, size_t count)
484{
485	struct ad7877 *ts = dev_get_drvdata(dev);
486	unsigned long val;
487	int error;
488
489	error = strict_strtoul(buf, 10, &val);
490	if (error)
491		return error;
492
493	if (val)
494		ad7877_disable(ts);
495	else
496		ad7877_enable(ts);
497
498	return count;
499}
500
501static DEVICE_ATTR(disable, 0664, ad7877_disable_show, ad7877_disable_store);
502
503static ssize_t ad7877_dac_show(struct device *dev,
504				     struct device_attribute *attr, char *buf)
505{
506	struct ad7877	*ts = dev_get_drvdata(dev);
507
508	return sprintf(buf, "%u\n", ts->dac);
509}
510
511static ssize_t ad7877_dac_store(struct device *dev,
512				     struct device_attribute *attr,
513				     const char *buf, size_t count)
514{
515	struct ad7877 *ts = dev_get_drvdata(dev);
516	unsigned long val;
517	int error;
518
519	error = strict_strtoul(buf, 10, &val);
520	if (error)
521		return error;
522
523	mutex_lock(&ts->mutex);
524	ts->dac = val & 0xFF;
525	ad7877_write(ts->spi, AD7877_REG_DAC, (ts->dac << 4) | AD7877_DAC_CONF);
526	mutex_unlock(&ts->mutex);
527
528	return count;
529}
530
531static DEVICE_ATTR(dac, 0664, ad7877_dac_show, ad7877_dac_store);
532
533static ssize_t ad7877_gpio3_show(struct device *dev,
534				     struct device_attribute *attr, char *buf)
535{
536	struct ad7877	*ts = dev_get_drvdata(dev);
537
538	return sprintf(buf, "%u\n", ts->gpio3);
539}
540
541static ssize_t ad7877_gpio3_store(struct device *dev,
542				     struct device_attribute *attr,
543				     const char *buf, size_t count)
544{
545	struct ad7877 *ts = dev_get_drvdata(dev);
546	unsigned long val;
547	int error;
548
549	error = strict_strtoul(buf, 10, &val);
550	if (error)
551		return error;
552
553	mutex_lock(&ts->mutex);
554	ts->gpio3 = !!val;
555	ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA |
556		 (ts->gpio4 << 4) | (ts->gpio3 << 5));
557	mutex_unlock(&ts->mutex);
558
559	return count;
560}
561
562static DEVICE_ATTR(gpio3, 0664, ad7877_gpio3_show, ad7877_gpio3_store);
563
564static ssize_t ad7877_gpio4_show(struct device *dev,
565				     struct device_attribute *attr, char *buf)
566{
567	struct ad7877	*ts = dev_get_drvdata(dev);
568
569	return sprintf(buf, "%u\n", ts->gpio4);
570}
571
572static ssize_t ad7877_gpio4_store(struct device *dev,
573				     struct device_attribute *attr,
574				     const char *buf, size_t count)
575{
576	struct ad7877 *ts = dev_get_drvdata(dev);
577	unsigned long val;
578	int error;
579
580	error = strict_strtoul(buf, 10, &val);
581	if (error)
582		return error;
583
584	mutex_lock(&ts->mutex);
585	ts->gpio4 = !!val;
586	ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA |
587		     (ts->gpio4 << 4) | (ts->gpio3 << 5));
588	mutex_unlock(&ts->mutex);
589
590	return count;
591}
592
593static DEVICE_ATTR(gpio4, 0664, ad7877_gpio4_show, ad7877_gpio4_store);
594
595static struct attribute *ad7877_attributes[] = {
596	&dev_attr_temp1.attr,
597	&dev_attr_temp2.attr,
598	&dev_attr_aux1.attr,
599	&dev_attr_aux2.attr,
600	&dev_attr_bat1.attr,
601	&dev_attr_bat2.attr,
602	&dev_attr_disable.attr,
603	&dev_attr_dac.attr,
604	&dev_attr_gpio4.attr,
605	NULL
606};
607
608static const struct attribute_group ad7877_attr_group = {
609	.attrs = ad7877_attributes,
610};
611
612static void ad7877_setup_ts_def_msg(struct spi_device *spi, struct ad7877 *ts)
613{
614	struct spi_message *m;
615	int i;
616
617	ts->cmd_crtl2 = AD7877_WRITEADD(AD7877_REG_CTRL2) |
618			AD7877_POL(ts->stopacq_polarity) |
619			AD7877_AVG(ts->averaging) | AD7877_PM(1) |
620			AD7877_TMR(ts->pen_down_acc_interval) |
621			AD7877_ACQ(ts->acquisition_time) |
622			AD7877_FCD(ts->first_conversion_delay);
623
624	ad7877_write(spi, AD7877_REG_CTRL2, ts->cmd_crtl2);
625
626	ts->cmd_crtl1 = AD7877_WRITEADD(AD7877_REG_CTRL1) |
627			AD7877_READADD(AD7877_REG_XPLUS-1) |
628			AD7877_MODE_SEQ1 | AD7877_DFR;
629
630	ad7877_write(spi, AD7877_REG_CTRL1, ts->cmd_crtl1);
631
632	ts->cmd_dummy = 0;
633
634	m = &ts->msg;
635
636	spi_message_init(m);
637
638	m->complete = ad7877_callback;
639	m->context = ts;
640
641	ts->xfer[0].tx_buf = &ts->cmd_crtl1;
642	ts->xfer[0].len = 2;
643
644	spi_message_add_tail(&ts->xfer[0], m);
645
646	ts->xfer[1].tx_buf = &ts->cmd_dummy; /* Send ZERO */
647	ts->xfer[1].len = 2;
648
649	spi_message_add_tail(&ts->xfer[1], m);
650
651	for (i = 0; i < 11; i++) {
652		ts->xfer[i + 2].rx_buf = &ts->conversion_data[AD7877_SEQ_YPOS + i];
653		ts->xfer[i + 2].len = 2;
654		spi_message_add_tail(&ts->xfer[i + 2], m);
655	}
656}
657
658static int __devinit ad7877_probe(struct spi_device *spi)
659{
660	struct ad7877			*ts;
661	struct input_dev		*input_dev;
662	struct ad7877_platform_data	*pdata = spi->dev.platform_data;
663	int				err;
664	u16				verify;
665
666	if (!spi->irq) {
667		dev_dbg(&spi->dev, "no IRQ?\n");
668		return -ENODEV;
669	}
670
671	if (!pdata) {
672		dev_dbg(&spi->dev, "no platform data?\n");
673		return -ENODEV;
674	}
675
676	/* don't exceed max specified SPI CLK frequency */
677	if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) {
678		dev_dbg(&spi->dev, "SPI CLK %d Hz?\n",spi->max_speed_hz);
679		return -EINVAL;
680	}
681
682	spi->bits_per_word = 16;
683	err = spi_setup(spi);
684	if (err) {
685		dev_dbg(&spi->dev, "spi master doesn't support 16 bits/word\n");
686		return err;
687	}
688
689	ts = kzalloc(sizeof(struct ad7877), GFP_KERNEL);
690	input_dev = input_allocate_device();
691	if (!ts || !input_dev) {
692		err = -ENOMEM;
693		goto err_free_mem;
694	}
695
696	dev_set_drvdata(&spi->dev, ts);
697	ts->spi = spi;
698	ts->input = input_dev;
699
700	setup_timer(&ts->timer, ad7877_timer, (unsigned long) ts);
701	mutex_init(&ts->mutex);
702	spin_lock_init(&ts->lock);
703
704	ts->model = pdata->model ? : 7877;
705	ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
706	ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
707	ts->pressure_max = pdata->pressure_max ? : ~0;
708
709	ts->stopacq_polarity = pdata->stopacq_polarity;
710	ts->first_conversion_delay = pdata->first_conversion_delay;
711	ts->acquisition_time = pdata->acquisition_time;
712	ts->averaging = pdata->averaging;
713	ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
714
715	snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev));
716
717	input_dev->name = "AD7877 Touchscreen";
718	input_dev->phys = ts->phys;
719	input_dev->dev.parent = &spi->dev;
720
721	__set_bit(EV_ABS, input_dev->evbit);
722	__set_bit(ABS_X, input_dev->absbit);
723	__set_bit(ABS_Y, input_dev->absbit);
724	__set_bit(ABS_PRESSURE, input_dev->absbit);
725
726	input_set_abs_params(input_dev, ABS_X,
727			pdata->x_min ? : 0,
728			pdata->x_max ? : MAX_12BIT,
729			0, 0);
730	input_set_abs_params(input_dev, ABS_Y,
731			pdata->y_min ? : 0,
732			pdata->y_max ? : MAX_12BIT,
733			0, 0);
734	input_set_abs_params(input_dev, ABS_PRESSURE,
735			pdata->pressure_min, pdata->pressure_max, 0, 0);
736
737	ad7877_write(spi, AD7877_REG_SEQ1, AD7877_MM_SEQUENCE);
738
739	verify = ad7877_read(spi, AD7877_REG_SEQ1);
740
741	if (verify != AD7877_MM_SEQUENCE){
742		dev_err(&spi->dev, "%s: Failed to probe %s\n",
743			dev_name(&spi->dev), input_dev->name);
744		err = -ENODEV;
745		goto err_free_mem;
746	}
747
748	if (gpio3)
749		ad7877_write(spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_3_CONF);
750
751	ad7877_setup_ts_def_msg(spi, ts);
752
753	/* Request AD7877 /DAV GPIO interrupt */
754
755	err = request_irq(spi->irq, ad7877_irq, IRQF_TRIGGER_FALLING,
756			spi->dev.driver->name, ts);
757	if (err) {
758		dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
759		goto err_free_mem;
760	}
761
762	err = sysfs_create_group(&spi->dev.kobj, &ad7877_attr_group);
763	if (err)
764		goto err_free_irq;
765
766	err = device_create_file(&spi->dev,
767				 gpio3 ? &dev_attr_gpio3 : &dev_attr_aux3);
768	if (err)
769		goto err_remove_attr_group;
770
771	err = input_register_device(input_dev);
772	if (err)
773		goto err_remove_attr;
774
775	return 0;
776
777err_remove_attr:
778	device_remove_file(&spi->dev,
779			   gpio3 ? &dev_attr_gpio3 : &dev_attr_aux3);
780err_remove_attr_group:
781	sysfs_remove_group(&spi->dev.kobj, &ad7877_attr_group);
782err_free_irq:
783	free_irq(spi->irq, ts);
784err_free_mem:
785	input_free_device(input_dev);
786	kfree(ts);
787	dev_set_drvdata(&spi->dev, NULL);
788	return err;
789}
790
791static int __devexit ad7877_remove(struct spi_device *spi)
792{
793	struct ad7877		*ts = dev_get_drvdata(&spi->dev);
794
795	sysfs_remove_group(&spi->dev.kobj, &ad7877_attr_group);
796	device_remove_file(&spi->dev,
797			   gpio3 ? &dev_attr_gpio3 : &dev_attr_aux3);
798
799	ad7877_disable(ts);
800	free_irq(ts->spi->irq, ts);
801
802	input_unregister_device(ts->input);
803	kfree(ts);
804
805	dev_dbg(&spi->dev, "unregistered touchscreen\n");
806	dev_set_drvdata(&spi->dev, NULL);
807
808	return 0;
809}
810
811#ifdef CONFIG_PM
812static int ad7877_suspend(struct spi_device *spi, pm_message_t message)
813{
814	struct ad7877 *ts = dev_get_drvdata(&spi->dev);
815
816	ad7877_disable(ts);
817
818	return 0;
819}
820
821static int ad7877_resume(struct spi_device *spi)
822{
823	struct ad7877 *ts = dev_get_drvdata(&spi->dev);
824
825	ad7877_enable(ts);
826
827	return 0;
828}
829#else
830#define ad7877_suspend NULL
831#define ad7877_resume  NULL
832#endif
833
834static struct spi_driver ad7877_driver = {
835	.driver = {
836		.name	= "ad7877",
837		.bus	= &spi_bus_type,
838		.owner	= THIS_MODULE,
839	},
840	.probe		= ad7877_probe,
841	.remove		= __devexit_p(ad7877_remove),
842	.suspend	= ad7877_suspend,
843	.resume		= ad7877_resume,
844};
845
846static int __init ad7877_init(void)
847{
848	return spi_register_driver(&ad7877_driver);
849}
850module_init(ad7877_init);
851
852static void __exit ad7877_exit(void)
853{
854	spi_unregister_driver(&ad7877_driver);
855}
856module_exit(ad7877_exit);
857
858MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
859MODULE_DESCRIPTION("AD7877 touchscreen Driver");
860MODULE_LICENSE("GPL");
861MODULE_ALIAS("spi:ad7877");
862