2 * Copyright (C) 2006-2008 Michael Hennerich, Analog Devices Inc.
4 * Description: AD7877 based touchscreen, sensor (ADCs), DAC and GPIO driver
7 * Bugs: Enter bugs at http://blackfin.uclinux.org/
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.
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.
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
25 * Copyright (c) 2005 David Brownell
26 * Copyright (c) 2006 Nokia Corporation
27 * Various changes: Imre Deak <imre.deak@nokia.com>
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
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>
45 #include <linux/slab.h>
46 #include <linux/spi/spi.h>
47 #include <linux/spi/ad7877.h>
50 #define TS_PEN_UP_TIMEOUT msecs_to_jiffies(100)
52 #define MAX_SPI_FREQ_HZ 20000000
53 #define MAX_12BIT ((1<<12)-1)
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
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)
110 AD7877_SEQ_TEMP1 = 8,
111 AD7877_SEQ_TEMP2 = 9,
113 AD7877_NR_SENSE = 11,
116 /* DAC Register Default RANGE 0 to Vcc, Volatge Mode, DAC On */
117 #define AD7877_DAC_CONF 0x1
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
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)
133 #define AD7877_SER (1 << 11) /* non-differential */
134 #define AD7877_DFR (0 << 11) /* differential */
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 */
141 #define AD7877_CHANADD(x) ((x&0xF)<<7)
142 #define AD7877_READADD(x) ((x)<<2)
143 #define AD7877_WRITEADD(x) ((x)<<12)
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))
149 #define AD7877_MM_SEQUENCE (AD7877_SEQ_YPLUS_BIT | AD7877_SEQ_XPLUS_BIT | \
150 AD7877_SEQ_Z2_BIT | AD7877_SEQ_Z1_BIT)
153 * Non-touchscreen sensors only use single-ended conversions.
160 struct spi_message msg;
161 struct spi_transfer xfer[6];
164 * DMA (thus cache coherency maintenance) requires the
165 * transfer buffers to live in their own cache lines.
167 u16 sample ____cacheline_aligned;
171 struct input_dev *input;
174 struct spi_device *spi;
176 u16 vref_delay_usecs;
186 u8 first_conversion_delay;
189 u8 pen_down_acc_interval;
191 struct spi_transfer xfer[AD7877_NR_SENSE + 2];
192 struct spi_message msg;
195 bool disabled; /* P: mutex */
196 bool gpio3; /* P: mutex */
197 bool gpio4; /* P: mutex */
200 struct timer_list timer; /* P: lock */
203 * DMA (thus cache coherency maintenance) requires the
204 * transfer buffers to live in their own cache lines.
206 u16 conversion_data[AD7877_NR_SENSE] ____cacheline_aligned;
210 module_param(gpio3, bool, 0);
211 MODULE_PARM_DESC(gpio3, "If gpio3 is set to 1 AUX3 acts as GPIO3");
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.
218 static int ad7877_read(struct spi_device *spi, u16 reg)
223 req = kzalloc(sizeof *req, GFP_KERNEL);
227 spi_message_init(&req->msg);
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;
235 req->xfer[1].rx_buf = &req->sample;
236 req->xfer[1].len = 2;
238 spi_message_add_tail(&req->xfer[0], &req->msg);
239 spi_message_add_tail(&req->xfer[1], &req->msg);
241 status = spi_sync(spi, &req->msg);
242 ret = status ? : req->sample;
249 static int ad7877_write(struct spi_device *spi, u16 reg, u16 val)
254 req = kzalloc(sizeof *req, GFP_KERNEL);
258 spi_message_init(&req->msg);
260 req->command = (u16) (AD7877_WRITEADD(reg) | (val & MAX_12BIT));
261 req->xfer[0].tx_buf = &req->command;
262 req->xfer[0].len = 2;
264 spi_message_add_tail(&req->xfer[0], &req->msg);
266 status = spi_sync(spi, &req->msg);
273 static int ad7877_read_adc(struct spi_device *spi, unsigned command)
275 struct ad7877 *ts = dev_get_drvdata(&spi->dev);
281 req = kzalloc(sizeof *req, GFP_KERNEL);
285 spi_message_init(&req->msg);
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);
293 req->reset = AD7877_WRITEADD(AD7877_REG_CTRL1) | AD7877_MODE_NOC;
295 req->command = (u16) command;
297 req->xfer[0].tx_buf = &req->reset;
298 req->xfer[0].len = 2;
299 req->xfer[0].cs_change = 1;
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;
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;
311 req->xfer[3].rx_buf = &req->sample;
312 req->xfer[3].len = 2;
313 req->xfer[3].cs_change = 1;
315 req->xfer[4].tx_buf = &ts->cmd_crtl2; /*REF OFF*/
316 req->xfer[4].len = 2;
317 req->xfer[4].cs_change = 1;
319 req->xfer[5].tx_buf = &ts->cmd_crtl1; /*DEFAULT*/
320 req->xfer[5].len = 2;
322 /* group all the transfers together, so we can't interfere with
323 * reading touchscreen state; disable penirq while sampling
325 for (i = 0; i < 6; i++)
326 spi_message_add_tail(&req->xfer[i], &req->msg);
328 status = spi_sync(spi, &req->msg);
329 sample = req->sample;
333 return status ? : sample;
336 static int ad7877_process_data(struct ad7877 *ts)
338 struct input_dev *input_dev = ts->input;
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;
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.
357 if (likely(x && z1)) {
358 /* compute touch pressure resistance using equation #1 */
359 Rt = (z2 - z1) * x * ts->x_plate_ohms;
361 Rt = (Rt + 2047) >> 12;
364 * Sample found inconsistent, pressure is beyond
365 * the maximum. Don't report it to user space.
367 if (Rt > ts->pressure_max)
370 if (!timer_pending(&ts->timer))
371 input_report_key(input_dev, BTN_TOUCH, 1);
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);
384 static inline void ad7877_ts_event_release(struct ad7877 *ts)
386 struct input_dev *input_dev = ts->input;
388 input_report_abs(input_dev, ABS_PRESSURE, 0);
389 input_report_key(input_dev, BTN_TOUCH, 0);
390 input_sync(input_dev);
393 static void ad7877_timer(unsigned long handle)
395 struct ad7877 *ts = (void *)handle;
398 spin_lock_irqsave(&ts->lock, flags);
399 ad7877_ts_event_release(ts);
400 spin_unlock_irqrestore(&ts->lock, flags);
403 static irqreturn_t ad7877_irq(int irq, void *handle)
405 struct ad7877 *ts = handle;
409 error = spi_sync(ts->spi, &ts->msg);
411 dev_err(&ts->spi->dev, "spi_sync --> %d\n", error);
415 spin_lock_irqsave(&ts->lock, flags);
416 error = ad7877_process_data(ts);
418 mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
419 spin_unlock_irqrestore(&ts->lock, flags);
425 static void ad7877_disable(struct ad7877 *ts)
427 mutex_lock(&ts->mutex);
431 disable_irq(ts->spi->irq);
433 if (del_timer_sync(&ts->timer))
434 ad7877_ts_event_release(ts);
438 * We know the chip's in lowpower mode since we always
439 * leave it that way after every request
442 mutex_unlock(&ts->mutex);
445 static void ad7877_enable(struct ad7877 *ts)
447 mutex_lock(&ts->mutex);
450 ts->disabled = false;
451 enable_irq(ts->spi->irq);
454 mutex_unlock(&ts->mutex);
457 #define SHOW(name) static ssize_t \
458 name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \
460 struct ad7877 *ts = dev_get_drvdata(dev); \
461 ssize_t v = ad7877_read_adc(ts->spi, \
462 AD7877_READ_CHAN(name)); \
465 return sprintf(buf, "%u\n", (unsigned) v); \
467 static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
477 static ssize_t ad7877_disable_show(struct device *dev,
478 struct device_attribute *attr, char *buf)
480 struct ad7877 *ts = dev_get_drvdata(dev);
482 return sprintf(buf, "%u\n", ts->disabled);
485 static ssize_t ad7877_disable_store(struct device *dev,
486 struct device_attribute *attr,
487 const char *buf, size_t count)
489 struct ad7877 *ts = dev_get_drvdata(dev);
493 error = strict_strtoul(buf, 10, &val);
505 static DEVICE_ATTR(disable, 0664, ad7877_disable_show, ad7877_disable_store);
507 static ssize_t ad7877_dac_show(struct device *dev,
508 struct device_attribute *attr, char *buf)
510 struct ad7877 *ts = dev_get_drvdata(dev);
512 return sprintf(buf, "%u\n", ts->dac);
515 static ssize_t ad7877_dac_store(struct device *dev,
516 struct device_attribute *attr,
517 const char *buf, size_t count)
519 struct ad7877 *ts = dev_get_drvdata(dev);
523 error = strict_strtoul(buf, 10, &val);
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);
535 static DEVICE_ATTR(dac, 0664, ad7877_dac_show, ad7877_dac_store);
537 static ssize_t ad7877_gpio3_show(struct device *dev,
538 struct device_attribute *attr, char *buf)
540 struct ad7877 *ts = dev_get_drvdata(dev);
542 return sprintf(buf, "%u\n", ts->gpio3);
545 static ssize_t ad7877_gpio3_store(struct device *dev,
546 struct device_attribute *attr,
547 const char *buf, size_t count)
549 struct ad7877 *ts = dev_get_drvdata(dev);
553 error = strict_strtoul(buf, 10, &val);
557 mutex_lock(&ts->mutex);
559 ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA |
560 (ts->gpio4 << 4) | (ts->gpio3 << 5));
561 mutex_unlock(&ts->mutex);
566 static DEVICE_ATTR(gpio3, 0664, ad7877_gpio3_show, ad7877_gpio3_store);
568 static ssize_t ad7877_gpio4_show(struct device *dev,
569 struct device_attribute *attr, char *buf)
571 struct ad7877 *ts = dev_get_drvdata(dev);
573 return sprintf(buf, "%u\n", ts->gpio4);
576 static ssize_t ad7877_gpio4_store(struct device *dev,
577 struct device_attribute *attr,
578 const char *buf, size_t count)
580 struct ad7877 *ts = dev_get_drvdata(dev);
584 error = strict_strtoul(buf, 10, &val);
588 mutex_lock(&ts->mutex);
590 ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA |
591 (ts->gpio4 << 4) | (ts->gpio3 << 5));
592 mutex_unlock(&ts->mutex);
597 static DEVICE_ATTR(gpio4, 0664, ad7877_gpio4_show, ad7877_gpio4_store);
599 static struct attribute *ad7877_attributes[] = {
600 &dev_attr_temp1.attr,
601 &dev_attr_temp2.attr,
607 &dev_attr_disable.attr,
609 &dev_attr_gpio3.attr,
610 &dev_attr_gpio4.attr,
614 static mode_t ad7877_attr_is_visible(struct kobject *kobj,
615 struct attribute *attr, int n)
617 mode_t mode = attr->mode;
619 if (attr == &dev_attr_aux3.attr) {
622 } else if (attr == &dev_attr_gpio3.attr) {
630 static const struct attribute_group ad7877_attr_group = {
631 .is_visible = ad7877_attr_is_visible,
632 .attrs = ad7877_attributes,
635 static void ad7877_setup_ts_def_msg(struct spi_device *spi, struct ad7877 *ts)
637 struct spi_message *m;
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);
647 ad7877_write(spi, AD7877_REG_CTRL2, ts->cmd_crtl2);
649 ts->cmd_crtl1 = AD7877_WRITEADD(AD7877_REG_CTRL1) |
650 AD7877_READADD(AD7877_REG_XPLUS-1) |
651 AD7877_MODE_SEQ1 | AD7877_DFR;
653 ad7877_write(spi, AD7877_REG_CTRL1, ts->cmd_crtl1);
663 ts->xfer[0].tx_buf = &ts->cmd_crtl1;
665 ts->xfer[0].cs_change = 1;
667 spi_message_add_tail(&ts->xfer[0], m);
669 ts->xfer[1].tx_buf = &ts->cmd_dummy; /* Send ZERO */
671 ts->xfer[1].cs_change = 1;
673 spi_message_add_tail(&ts->xfer[1], m);
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);
684 static int __devinit ad7877_probe(struct spi_device *spi)
687 struct input_dev *input_dev;
688 struct ad7877_platform_data *pdata = spi->dev.platform_data;
693 dev_dbg(&spi->dev, "no IRQ?\n");
698 dev_dbg(&spi->dev, "no platform data?\n");
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);
708 spi->bits_per_word = 16;
709 err = spi_setup(spi);
711 dev_dbg(&spi->dev, "spi master doesn't support 16 bits/word\n");
715 ts = kzalloc(sizeof(struct ad7877), GFP_KERNEL);
716 input_dev = input_allocate_device();
717 if (!ts || !input_dev) {
722 dev_set_drvdata(&spi->dev, ts);
724 ts->input = input_dev;
726 setup_timer(&ts->timer, ad7877_timer, (unsigned long) ts);
727 mutex_init(&ts->mutex);
728 spin_lock_init(&ts->lock);
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;
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;
741 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev));
743 input_dev->name = "AD7877 Touchscreen";
744 input_dev->phys = ts->phys;
745 input_dev->dev.parent = &spi->dev;
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);
754 input_set_abs_params(input_dev, ABS_X,
756 pdata->x_max ? : MAX_12BIT,
758 input_set_abs_params(input_dev, ABS_Y,
760 pdata->y_max ? : MAX_12BIT,
762 input_set_abs_params(input_dev, ABS_PRESSURE,
763 pdata->pressure_min, pdata->pressure_max, 0, 0);
765 ad7877_write(spi, AD7877_REG_SEQ1, AD7877_MM_SEQUENCE);
767 verify = ad7877_read(spi, AD7877_REG_SEQ1);
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);
777 ad7877_write(spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_3_CONF);
779 ad7877_setup_ts_def_msg(spi, ts);
781 /* Request AD7877 /DAV GPIO interrupt */
783 err = request_threaded_irq(spi->irq, NULL, ad7877_irq,
784 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
785 spi->dev.driver->name, ts);
787 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
791 err = sysfs_create_group(&spi->dev.kobj, &ad7877_attr_group);
795 err = input_register_device(input_dev);
797 goto err_remove_attr_group;
801 err_remove_attr_group:
802 sysfs_remove_group(&spi->dev.kobj, &ad7877_attr_group);
804 free_irq(spi->irq, ts);
806 input_free_device(input_dev);
808 dev_set_drvdata(&spi->dev, NULL);
812 static int __devexit ad7877_remove(struct spi_device *spi)
814 struct ad7877 *ts = dev_get_drvdata(&spi->dev);
816 sysfs_remove_group(&spi->dev.kobj, &ad7877_attr_group);
819 free_irq(ts->spi->irq, ts);
821 input_unregister_device(ts->input);
824 dev_dbg(&spi->dev, "unregistered touchscreen\n");
825 dev_set_drvdata(&spi->dev, NULL);
830 #ifdef CONFIG_PM_SLEEP
831 static int ad7877_suspend(struct device *dev)
833 struct ad7877 *ts = dev_get_drvdata(dev);
840 static int ad7877_resume(struct device *dev)
842 struct ad7877 *ts = dev_get_drvdata(dev);
850 static SIMPLE_DEV_PM_OPS(ad7877_pm, ad7877_suspend, ad7877_resume);
852 static struct spi_driver ad7877_driver = {
855 .bus = &spi_bus_type,
856 .owner = THIS_MODULE,
859 .probe = ad7877_probe,
860 .remove = __devexit_p(ad7877_remove),
863 static int __init ad7877_init(void)
865 return spi_register_driver(&ad7877_driver);
867 module_init(ad7877_init);
869 static void __exit ad7877_exit(void)
871 spi_unregister_driver(&ad7877_driver);
873 module_exit(ad7877_exit);
875 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
876 MODULE_DESCRIPTION("AD7877 touchscreen Driver");
877 MODULE_LICENSE("GPL");
878 MODULE_ALIAS("spi:ad7877");