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/delay.h>
 41#include <linux/input.h>
 42#include <linux/interrupt.h>
 43#include <linux/pm.h>
 44#include <linux/slab.h>
 45#include <linux/spi/spi.h>
 46#include <linux/spi/ad7877.h>
 47#include <linux/module.h>
 48#include <asm/irq.h>
 49
 50#define	TS_PEN_UP_TIMEOUT	msecs_to_jiffies(100)
 51
 52#define MAX_SPI_FREQ_HZ			20000000
 53#define	MAX_12BIT			((1<<12)-1)
 54
 55#define AD7877_REG_ZEROS			0
 56#define AD7877_REG_CTRL1			1
 57#define AD7877_REG_CTRL2			2
 58#define AD7877_REG_ALERT			3
 59#define AD7877_REG_AUX1HIGH			4
 60#define AD7877_REG_AUX1LOW			5
 61#define AD7877_REG_BAT1HIGH			6
 62#define AD7877_REG_BAT1LOW			7
 63#define AD7877_REG_BAT2HIGH			8
 64#define AD7877_REG_BAT2LOW			9
 65#define AD7877_REG_TEMP1HIGH			10
 66#define AD7877_REG_TEMP1LOW			11
 67#define AD7877_REG_SEQ0				12
 68#define AD7877_REG_SEQ1				13
 69#define AD7877_REG_DAC				14
 70#define AD7877_REG_NONE1			15
 71#define AD7877_REG_EXTWRITE			15
 72#define AD7877_REG_XPLUS			16
 73#define AD7877_REG_YPLUS			17
 74#define AD7877_REG_Z2				18
 75#define AD7877_REG_aux1				19
 76#define AD7877_REG_aux2				20
 77#define AD7877_REG_aux3				21
 78#define AD7877_REG_bat1				22
 79#define AD7877_REG_bat2				23
 80#define AD7877_REG_temp1			24
 81#define AD7877_REG_temp2			25
 82#define AD7877_REG_Z1				26
 83#define AD7877_REG_GPIOCTRL1			27
 84#define AD7877_REG_GPIOCTRL2			28
 85#define AD7877_REG_GPIODATA			29
 86#define AD7877_REG_NONE2			30
 87#define AD7877_REG_NONE3			31
 88
 89#define AD7877_SEQ_YPLUS_BIT			(1<<11)
 90#define AD7877_SEQ_XPLUS_BIT			(1<<10)
 91#define AD7877_SEQ_Z2_BIT			(1<<9)
 92#define AD7877_SEQ_AUX1_BIT			(1<<8)
 93#define AD7877_SEQ_AUX2_BIT			(1<<7)
 94#define AD7877_SEQ_AUX3_BIT			(1<<6)
 95#define AD7877_SEQ_BAT1_BIT			(1<<5)
 96#define AD7877_SEQ_BAT2_BIT			(1<<4)
 97#define AD7877_SEQ_TEMP1_BIT			(1<<3)
 98#define AD7877_SEQ_TEMP2_BIT			(1<<2)
 99#define AD7877_SEQ_Z1_BIT			(1<<1)
100
101enum {
102	AD7877_SEQ_YPOS  = 0,
103	AD7877_SEQ_XPOS  = 1,
104	AD7877_SEQ_Z2    = 2,
105	AD7877_SEQ_AUX1  = 3,
106	AD7877_SEQ_AUX2  = 4,
107	AD7877_SEQ_AUX3  = 5,
108	AD7877_SEQ_BAT1  = 6,
109	AD7877_SEQ_BAT2  = 7,
110	AD7877_SEQ_TEMP1 = 8,
111	AD7877_SEQ_TEMP2 = 9,
112	AD7877_SEQ_Z1    = 10,
113	AD7877_NR_SENSE  = 11,
114};
115
116/* DAC Register Default RANGE 0 to Vcc, Volatge Mode, DAC On */
117#define AD7877_DAC_CONF			0x1
118
119/* If gpio3 is set AUX3/GPIO3 acts as GPIO Output */
120#define AD7877_EXTW_GPIO_3_CONF		0x1C4
121#define AD7877_EXTW_GPIO_DATA		0x200
122
123/* Control REG 2 */
124#define AD7877_TMR(x)			((x & 0x3) << 0)
125#define AD7877_REF(x)			((x & 0x1) << 2)
126#define AD7877_POL(x)			((x & 0x1) << 3)
127#define AD7877_FCD(x)			((x & 0x3) << 4)
128#define AD7877_PM(x)			((x & 0x3) << 6)
129#define AD7877_ACQ(x)			((x & 0x3) << 8)
130#define AD7877_AVG(x)			((x & 0x3) << 10)
131
132/* Control REG 1 */
133#define	AD7877_SER			(1 << 11)	/* non-differential */
134#define	AD7877_DFR			(0 << 11)	/* differential */
135
136#define AD7877_MODE_NOC  (0)	/* Do not convert */
137#define AD7877_MODE_SCC  (1)	/* Single channel conversion */
138#define AD7877_MODE_SEQ0 (2)	/* Sequence 0 in Slave Mode */
139#define AD7877_MODE_SEQ1 (3)	/* Sequence 1 in Master Mode */
140
141#define AD7877_CHANADD(x)		((x&0xF)<<7)
142#define AD7877_READADD(x)		((x)<<2)
143#define AD7877_WRITEADD(x)		((x)<<12)
144
145#define AD7877_READ_CHAN(x) (AD7877_WRITEADD(AD7877_REG_CTRL1) | AD7877_SER | \
146		AD7877_MODE_SCC | AD7877_CHANADD(AD7877_REG_ ## x) | \
147		AD7877_READADD(AD7877_REG_ ## x))
148
149#define AD7877_MM_SEQUENCE (AD7877_SEQ_YPLUS_BIT | AD7877_SEQ_XPLUS_BIT | \
150		AD7877_SEQ_Z2_BIT | AD7877_SEQ_Z1_BIT)
151
152/*
153 * Non-touchscreen sensors only use single-ended conversions.
154 */
155
156struct ser_req {
157	u16			reset;
158	u16			ref_on;
159	u16			command;
160	struct spi_message	msg;
161	struct spi_transfer	xfer[6];
162
163	/*
164	 * DMA (thus cache coherency maintenance) requires the
165	 * transfer buffers to live in their own cache lines.
166	 */
167	u16 sample ____cacheline_aligned;
168};
169
170struct ad7877 {
171	struct input_dev	*input;
172	char			phys[32];
173
174	struct spi_device	*spi;
175	u16			model;
176	u16			vref_delay_usecs;
177	u16			x_plate_ohms;
178	u16			pressure_max;
179
180	u16			cmd_crtl1;
181	u16			cmd_crtl2;
182	u16			cmd_dummy;
183	u16			dac;
184
185	u8			stopacq_polarity;
186	u8			first_conversion_delay;
187	u8			acquisition_time;
188	u8			averaging;
189	u8			pen_down_acc_interval;
190
191	struct spi_transfer	xfer[AD7877_NR_SENSE + 2];
192	struct spi_message	msg;
193
194	struct mutex		mutex;
195	bool			disabled;	/* P: mutex */
196	bool			gpio3;		/* P: mutex */
197	bool			gpio4;		/* P: mutex */
198
199	spinlock_t		lock;
200	struct timer_list	timer;		/* 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 bool gpio3;
210module_param(gpio3, bool, 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	req->xfer[0].cs_change = 1;
234
235	req->xfer[1].rx_buf = &req->sample;
236	req->xfer[1].len = 2;
237
238	spi_message_add_tail(&req->xfer[0], &req->msg);
239	spi_message_add_tail(&req->xfer[1], &req->msg);
240
241	status = spi_sync(spi, &req->msg);
242	ret = status ? : req->sample;
243
244	kfree(req);
245
246	return ret;
247}
248
249static int ad7877_write(struct spi_device *spi, u16 reg, u16 val)
250{
251	struct ser_req *req;
252	int status;
253
254	req = kzalloc(sizeof *req, GFP_KERNEL);
255	if (!req)
256		return -ENOMEM;
257
258	spi_message_init(&req->msg);
259
260	req->command = (u16) (AD7877_WRITEADD(reg) | (val & MAX_12BIT));
261	req->xfer[0].tx_buf = &req->command;
262	req->xfer[0].len = 2;
263
264	spi_message_add_tail(&req->xfer[0], &req->msg);
265
266	status = spi_sync(spi, &req->msg);
267
268	kfree(req);
269
270	return status;
271}
272
273static int ad7877_read_adc(struct spi_device *spi, unsigned command)
274{
275	struct ad7877 *ts = spi_get_drvdata(spi);
276	struct ser_req *req;
277	int status;
278	int sample;
279	int i;
280
281	req = kzalloc(sizeof *req, GFP_KERNEL);
282	if (!req)
283		return -ENOMEM;
284
285	spi_message_init(&req->msg);
286
287	/* activate reference, so it has time to settle; */
288	req->ref_on = AD7877_WRITEADD(AD7877_REG_CTRL2) |
289			 AD7877_POL(ts->stopacq_polarity) |
290			 AD7877_AVG(0) | AD7877_PM(2) | AD7877_TMR(0) |
291			 AD7877_ACQ(ts->acquisition_time) | AD7877_FCD(0);
292
293	req->reset = AD7877_WRITEADD(AD7877_REG_CTRL1) | AD7877_MODE_NOC;
294
295	req->command = (u16) command;
296
297	req->xfer[0].tx_buf = &req->reset;
298	req->xfer[0].len = 2;
299	req->xfer[0].cs_change = 1;
300
301	req->xfer[1].tx_buf = &req->ref_on;
302	req->xfer[1].len = 2;
303	req->xfer[1].delay_usecs = ts->vref_delay_usecs;
304	req->xfer[1].cs_change = 1;
305
306	req->xfer[2].tx_buf = &req->command;
307	req->xfer[2].len = 2;
308	req->xfer[2].delay_usecs = ts->vref_delay_usecs;
309	req->xfer[2].cs_change = 1;
310
311	req->xfer[3].rx_buf = &req->sample;
312	req->xfer[3].len = 2;
313	req->xfer[3].cs_change = 1;
314
315	req->xfer[4].tx_buf = &ts->cmd_crtl2;	/*REF OFF*/
316	req->xfer[4].len = 2;
317	req->xfer[4].cs_change = 1;
318
319	req->xfer[5].tx_buf = &ts->cmd_crtl1;	/*DEFAULT*/
320	req->xfer[5].len = 2;
321
322	/* group all the transfers together, so we can't interfere with
323	 * reading touchscreen state; disable penirq while sampling
324	 */
325	for (i = 0; i < 6; i++)
326		spi_message_add_tail(&req->xfer[i], &req->msg);
327
328	status = spi_sync(spi, &req->msg);
329	sample = req->sample;
330
331	kfree(req);
332
333	return status ? : sample;
334}
335
336static int ad7877_process_data(struct ad7877 *ts)
337{
338	struct input_dev *input_dev = ts->input;
339	unsigned Rt;
340	u16 x, y, z1, z2;
341
342	x = ts->conversion_data[AD7877_SEQ_XPOS] & MAX_12BIT;
343	y = ts->conversion_data[AD7877_SEQ_YPOS] & MAX_12BIT;
344	z1 = ts->conversion_data[AD7877_SEQ_Z1] & MAX_12BIT;
345	z2 = ts->conversion_data[AD7877_SEQ_Z2] & MAX_12BIT;
346
347	/*
348	 * The samples processed here are already preprocessed by the AD7877.
349	 * The preprocessing function consists of an averaging filter.
350	 * The combination of 'first conversion delay' and averaging provides a robust solution,
351	 * discarding the spurious noise in the signal and keeping only the data of interest.
352	 * The size of the averaging filter is programmable. (dev.platform_data, see linux/spi/ad7877.h)
353	 * Other user-programmable conversion controls include variable acquisition time,
354	 * and first conversion delay. Up to 16 averages can be taken per conversion.
355	 */
356
357	if (likely(x && z1)) {
358		/* compute touch pressure resistance using equation #1 */
359		Rt = (z2 - z1) * x * ts->x_plate_ohms;
360		Rt /= z1;
361		Rt = (Rt + 2047) >> 12;
362
363		/*
364		 * Sample found inconsistent, pressure is beyond
365		 * the maximum. Don't report it to user space.
366		 */
367		if (Rt > ts->pressure_max)
368			return -EINVAL;
369
370		if (!timer_pending(&ts->timer))
371			input_report_key(input_dev, BTN_TOUCH, 1);
372
373		input_report_abs(input_dev, ABS_X, x);
374		input_report_abs(input_dev, ABS_Y, y);
375		input_report_abs(input_dev, ABS_PRESSURE, Rt);
376		input_sync(input_dev);
377
378		return 0;
379	}
380
381	return -EINVAL;
382}
383
384static inline void ad7877_ts_event_release(struct ad7877 *ts)
385{
386	struct input_dev *input_dev = ts->input;
387
388	input_report_abs(input_dev, ABS_PRESSURE, 0);
389	input_report_key(input_dev, BTN_TOUCH, 0);
390	input_sync(input_dev);
391}
392
393static void ad7877_timer(unsigned long handle)
394{
395	struct ad7877 *ts = (void *)handle;
396	unsigned long flags;
397
398	spin_lock_irqsave(&ts->lock, flags);
399	ad7877_ts_event_release(ts);
400	spin_unlock_irqrestore(&ts->lock, flags);
401}
402
403static irqreturn_t ad7877_irq(int irq, void *handle)
404{
405	struct ad7877 *ts = handle;
406	unsigned long flags;
407	int error;
408
409	error = spi_sync(ts->spi, &ts->msg);
410	if (error) {
411		dev_err(&ts->spi->dev, "spi_sync --> %d\n", error);
412		goto out;
413	}
414
415	spin_lock_irqsave(&ts->lock, flags);
416	error = ad7877_process_data(ts);
417	if (!error)
418		mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
419	spin_unlock_irqrestore(&ts->lock, flags);
420
421out:
422	return IRQ_HANDLED;
423}
424
425static void ad7877_disable(struct ad7877 *ts)
426{
427	mutex_lock(&ts->mutex);
428
429	if (!ts->disabled) {
430		ts->disabled = true;
431		disable_irq(ts->spi->irq);
432
433		if (del_timer_sync(&ts->timer))
434			ad7877_ts_event_release(ts);
435	}
436
437	/*
438	 * We know the chip's in lowpower mode since we always
439	 * leave it that way after every request
440	 */
441
442	mutex_unlock(&ts->mutex);
443}
444
445static void ad7877_enable(struct ad7877 *ts)
446{
447	mutex_lock(&ts->mutex);
448
449	if (ts->disabled) {
450		ts->disabled = false;
451		enable_irq(ts->spi->irq);
452	}
453
454	mutex_unlock(&ts->mutex);
455}
456
457#define SHOW(name) static ssize_t \
458name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \
459{ \
460	struct ad7877 *ts = dev_get_drvdata(dev); \
461	ssize_t v = ad7877_read_adc(ts->spi, \
462			AD7877_READ_CHAN(name)); \
463	if (v < 0) \
464		return v; \
465	return sprintf(buf, "%u\n", (unsigned) v); \
466} \
467static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
468
469SHOW(aux1)
470SHOW(aux2)
471SHOW(aux3)
472SHOW(bat1)
473SHOW(bat2)
474SHOW(temp1)
475SHOW(temp2)
476
477static ssize_t ad7877_disable_show(struct device *dev,
478				     struct device_attribute *attr, char *buf)
479{
480	struct ad7877 *ts = dev_get_drvdata(dev);
481
482	return sprintf(buf, "%u\n", ts->disabled);
483}
484
485static ssize_t ad7877_disable_store(struct device *dev,
486				     struct device_attribute *attr,
487				     const char *buf, size_t count)
488{
489	struct ad7877 *ts = dev_get_drvdata(dev);
490	unsigned int val;
491	int error;
492
493	error = kstrtouint(buf, 10, &val);
494	if (error)
495		return error;
496
497	if (val)
498		ad7877_disable(ts);
499	else
500		ad7877_enable(ts);
501
502	return count;
503}
504
505static DEVICE_ATTR(disable, 0664, ad7877_disable_show, ad7877_disable_store);
506
507static ssize_t ad7877_dac_show(struct device *dev,
508				     struct device_attribute *attr, char *buf)
509{
510	struct ad7877 *ts = dev_get_drvdata(dev);
511
512	return sprintf(buf, "%u\n", ts->dac);
513}
514
515static ssize_t ad7877_dac_store(struct device *dev,
516				     struct device_attribute *attr,
517				     const char *buf, size_t count)
518{
519	struct ad7877 *ts = dev_get_drvdata(dev);
520	unsigned int val;
521	int error;
522
523	error = kstrtouint(buf, 10, &val);
524	if (error)
525		return error;
526
527	mutex_lock(&ts->mutex);
528	ts->dac = val & 0xFF;
529	ad7877_write(ts->spi, AD7877_REG_DAC, (ts->dac << 4) | AD7877_DAC_CONF);
530	mutex_unlock(&ts->mutex);
531
532	return count;
533}
534
535static DEVICE_ATTR(dac, 0664, ad7877_dac_show, ad7877_dac_store);
536
537static ssize_t ad7877_gpio3_show(struct device *dev,
538				     struct device_attribute *attr, char *buf)
539{
540	struct ad7877 *ts = dev_get_drvdata(dev);
541
542	return sprintf(buf, "%u\n", ts->gpio3);
543}
544
545static ssize_t ad7877_gpio3_store(struct device *dev,
546				     struct device_attribute *attr,
547				     const char *buf, size_t count)
548{
549	struct ad7877 *ts = dev_get_drvdata(dev);
550	unsigned int val;
551	int error;
552
553	error = kstrtouint(buf, 10, &val);
554	if (error)
555		return error;
556
557	mutex_lock(&ts->mutex);
558	ts->gpio3 = !!val;
559	ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA |
560		 (ts->gpio4 << 4) | (ts->gpio3 << 5));
561	mutex_unlock(&ts->mutex);
562
563	return count;
564}
565
566static DEVICE_ATTR(gpio3, 0664, ad7877_gpio3_show, ad7877_gpio3_store);
567
568static ssize_t ad7877_gpio4_show(struct device *dev,
569				     struct device_attribute *attr, char *buf)
570{
571	struct ad7877 *ts = dev_get_drvdata(dev);
572
573	return sprintf(buf, "%u\n", ts->gpio4);
574}
575
576static ssize_t ad7877_gpio4_store(struct device *dev,
577				     struct device_attribute *attr,
578				     const char *buf, size_t count)
579{
580	struct ad7877 *ts = dev_get_drvdata(dev);
581	unsigned int val;
582	int error;
583
584	error = kstrtouint(buf, 10, &val);
585	if (error)
586		return error;
587
588	mutex_lock(&ts->mutex);
589	ts->gpio4 = !!val;
590	ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA |
591		     (ts->gpio4 << 4) | (ts->gpio3 << 5));
592	mutex_unlock(&ts->mutex);
593
594	return count;
595}
596
597static DEVICE_ATTR(gpio4, 0664, ad7877_gpio4_show, ad7877_gpio4_store);
598
599static struct attribute *ad7877_attributes[] = {
600	&dev_attr_temp1.attr,
601	&dev_attr_temp2.attr,
602	&dev_attr_aux1.attr,
603	&dev_attr_aux2.attr,
604	&dev_attr_aux3.attr,
605	&dev_attr_bat1.attr,
606	&dev_attr_bat2.attr,
607	&dev_attr_disable.attr,
608	&dev_attr_dac.attr,
609	&dev_attr_gpio3.attr,
610	&dev_attr_gpio4.attr,
611	NULL
612};
613
614static umode_t ad7877_attr_is_visible(struct kobject *kobj,
615				     struct attribute *attr, int n)
616{
617	umode_t mode = attr->mode;
618
619	if (attr == &dev_attr_aux3.attr) {
620		if (gpio3)
621			mode = 0;
622	} else if (attr == &dev_attr_gpio3.attr) {
623		if (!gpio3)
624			mode = 0;
625	}
626
627	return mode;
628}
629
630static const struct attribute_group ad7877_attr_group = {
631	.is_visible	= ad7877_attr_is_visible,
632	.attrs		= ad7877_attributes,
633};
634
635static void ad7877_setup_ts_def_msg(struct spi_device *spi, struct ad7877 *ts)
636{
637	struct spi_message *m;
638	int i;
639
640	ts->cmd_crtl2 = AD7877_WRITEADD(AD7877_REG_CTRL2) |
641			AD7877_POL(ts->stopacq_polarity) |
642			AD7877_AVG(ts->averaging) | AD7877_PM(1) |
643			AD7877_TMR(ts->pen_down_acc_interval) |
644			AD7877_ACQ(ts->acquisition_time) |
645			AD7877_FCD(ts->first_conversion_delay);
646
647	ad7877_write(spi, AD7877_REG_CTRL2, ts->cmd_crtl2);
648
649	ts->cmd_crtl1 = AD7877_WRITEADD(AD7877_REG_CTRL1) |
650			AD7877_READADD(AD7877_REG_XPLUS-1) |
651			AD7877_MODE_SEQ1 | AD7877_DFR;
652
653	ad7877_write(spi, AD7877_REG_CTRL1, ts->cmd_crtl1);
654
655	ts->cmd_dummy = 0;
656
657	m = &ts->msg;
658
659	spi_message_init(m);
660
661	m->context = ts;
662
663	ts->xfer[0].tx_buf = &ts->cmd_crtl1;
664	ts->xfer[0].len = 2;
665	ts->xfer[0].cs_change = 1;
666
667	spi_message_add_tail(&ts->xfer[0], m);
668
669	ts->xfer[1].tx_buf = &ts->cmd_dummy; /* Send ZERO */
670	ts->xfer[1].len = 2;
671	ts->xfer[1].cs_change = 1;
672
673	spi_message_add_tail(&ts->xfer[1], m);
674
675	for (i = 0; i < AD7877_NR_SENSE; i++) {
676		ts->xfer[i + 2].rx_buf = &ts->conversion_data[AD7877_SEQ_YPOS + i];
677		ts->xfer[i + 2].len = 2;
678		if (i < (AD7877_NR_SENSE - 1))
679			ts->xfer[i + 2].cs_change = 1;
680		spi_message_add_tail(&ts->xfer[i + 2], m);
681	}
682}
683
684static int ad7877_probe(struct spi_device *spi)
685{
686	struct ad7877			*ts;
687	struct input_dev		*input_dev;
688	struct ad7877_platform_data	*pdata = dev_get_platdata(&spi->dev);
689	int				err;
690	u16				verify;
691
692	if (!spi->irq) {
693		dev_dbg(&spi->dev, "no IRQ?\n");
694		return -ENODEV;
695	}
696
697	if (!pdata) {
698		dev_dbg(&spi->dev, "no platform data?\n");
699		return -ENODEV;
700	}
701
702	/* don't exceed max specified SPI CLK frequency */
703	if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) {
704		dev_dbg(&spi->dev, "SPI CLK %d Hz?\n",spi->max_speed_hz);
705		return -EINVAL;
706	}
707
708	spi->bits_per_word = 16;
709	err = spi_setup(spi);
710	if (err) {
711		dev_dbg(&spi->dev, "spi master doesn't support 16 bits/word\n");
712		return err;
713	}
714
715	ts = kzalloc(sizeof(struct ad7877), GFP_KERNEL);
716	input_dev = input_allocate_device();
717	if (!ts || !input_dev) {
718		err = -ENOMEM;
719		goto err_free_mem;
720	}
721
722	spi_set_drvdata(spi, ts);
723	ts->spi = spi;
724	ts->input = input_dev;
725
726	setup_timer(&ts->timer, ad7877_timer, (unsigned long) ts);
727	mutex_init(&ts->mutex);
728	spin_lock_init(&ts->lock);
729
730	ts->model = pdata->model ? : 7877;
731	ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
732	ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
733	ts->pressure_max = pdata->pressure_max ? : ~0;
734
735	ts->stopacq_polarity = pdata->stopacq_polarity;
736	ts->first_conversion_delay = pdata->first_conversion_delay;
737	ts->acquisition_time = pdata->acquisition_time;
738	ts->averaging = pdata->averaging;
739	ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
740
741	snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev));
742
743	input_dev->name = "AD7877 Touchscreen";
744	input_dev->phys = ts->phys;
745	input_dev->dev.parent = &spi->dev;
746
747	__set_bit(EV_KEY, input_dev->evbit);
748	__set_bit(BTN_TOUCH, input_dev->keybit);
749	__set_bit(EV_ABS, input_dev->evbit);
750	__set_bit(ABS_X, input_dev->absbit);
751	__set_bit(ABS_Y, input_dev->absbit);
752	__set_bit(ABS_PRESSURE, input_dev->absbit);
753
754	input_set_abs_params(input_dev, ABS_X,
755			pdata->x_min ? : 0,
756			pdata->x_max ? : MAX_12BIT,
757			0, 0);
758	input_set_abs_params(input_dev, ABS_Y,
759			pdata->y_min ? : 0,
760			pdata->y_max ? : MAX_12BIT,
761			0, 0);
762	input_set_abs_params(input_dev, ABS_PRESSURE,
763			pdata->pressure_min, pdata->pressure_max, 0, 0);
764
765	ad7877_write(spi, AD7877_REG_SEQ1, AD7877_MM_SEQUENCE);
766
767	verify = ad7877_read(spi, AD7877_REG_SEQ1);
768
769	if (verify != AD7877_MM_SEQUENCE){
770		dev_err(&spi->dev, "%s: Failed to probe %s\n",
771			dev_name(&spi->dev), input_dev->name);
772		err = -ENODEV;
773		goto err_free_mem;
774	}
775
776	if (gpio3)
777		ad7877_write(spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_3_CONF);
778
779	ad7877_setup_ts_def_msg(spi, ts);
780
781	/* Request AD7877 /DAV GPIO interrupt */
782
783	err = request_threaded_irq(spi->irq, NULL, ad7877_irq,
784				   IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
785				   spi->dev.driver->name, ts);
786	if (err) {
787		dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
788		goto err_free_mem;
789	}
790
791	err = sysfs_create_group(&spi->dev.kobj, &ad7877_attr_group);
792	if (err)
793		goto err_free_irq;
794
795	err = input_register_device(input_dev);
796	if (err)
797		goto err_remove_attr_group;
798
799	return 0;
800
801err_remove_attr_group:
802	sysfs_remove_group(&spi->dev.kobj, &ad7877_attr_group);
803err_free_irq:
804	free_irq(spi->irq, ts);
805err_free_mem:
806	input_free_device(input_dev);
807	kfree(ts);
 
808	return err;
809}
810
811static int ad7877_remove(struct spi_device *spi)
812{
813	struct ad7877 *ts = spi_get_drvdata(spi);
814
815	sysfs_remove_group(&spi->dev.kobj, &ad7877_attr_group);
816
817	ad7877_disable(ts);
818	free_irq(ts->spi->irq, ts);
819
820	input_unregister_device(ts->input);
821	kfree(ts);
822
823	dev_dbg(&spi->dev, "unregistered touchscreen\n");
 
824
825	return 0;
826}
827
828#ifdef CONFIG_PM_SLEEP
829static int ad7877_suspend(struct device *dev)
830{
831	struct ad7877 *ts = dev_get_drvdata(dev);
832
833	ad7877_disable(ts);
834
835	return 0;
836}
837
838static int ad7877_resume(struct device *dev)
839{
840	struct ad7877 *ts = dev_get_drvdata(dev);
841
842	ad7877_enable(ts);
843
844	return 0;
845}
846#endif
847
848static SIMPLE_DEV_PM_OPS(ad7877_pm, ad7877_suspend, ad7877_resume);
849
850static struct spi_driver ad7877_driver = {
851	.driver = {
852		.name	= "ad7877",
 
853		.owner	= THIS_MODULE,
854		.pm	= &ad7877_pm,
855	},
856	.probe		= ad7877_probe,
857	.remove		= ad7877_remove,
858};
859
860module_spi_driver(ad7877_driver);
 
 
 
 
 
 
 
 
 
 
861
862MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
863MODULE_DESCRIPTION("AD7877 touchscreen Driver");
864MODULE_LICENSE("GPL");
865MODULE_ALIAS("spi:ad7877");