2 * ADS7846 based touchscreen and sensor driver
4 * Copyright (c) 2005 David Brownell
5 * Copyright (c) 2006 Nokia Corporation
6 * Various changes: Imre Deak <imre.deak@nokia.com>
10 * Copyright (C) 2004-2005 Richard Purdie
11 * - omap_ts.[hc], ads7846.h, ts_osk.c
12 * Copyright (C) 2002 MontaVista Software
13 * Copyright (C) 2004 Texas Instruments
14 * Copyright (C) 2005 Dirk Behme
16 * This program is free software; you can redistribute it and/or modify
17 * it under the terms of the GNU General Public License version 2 as
18 * published by the Free Software Foundation.
20 #include <linux/device.h>
21 #include <linux/init.h>
22 #include <linux/delay.h>
23 #include <linux/input.h>
24 #include <linux/interrupt.h>
25 #include <linux/slab.h>
26 #include <linux/spi/spi.h>
27 #include <linux/spi/ads7846.h>
31 #include <asm/mach-types.h>
32 #ifdef CONFIG_ARCH_OMAP
33 #include <asm/arch/gpio.h>
39 * This code has been heavily tested on a Nokia 770, and lightly
40 * tested on other ads7846 devices (OSK/Mistral, Lubbock).
41 * Support for ads7843 and ads7845 has only been stubbed in.
43 * IRQ handling needs a workaround because of a shortcoming in handling
44 * edge triggered IRQs on some platforms like the OMAP1/2. These
45 * platforms don't handle the ARM lazy IRQ disabling properly, thus we
46 * have to maintain our own SW IRQ disabled status. This should be
47 * removed as soon as the affected platform's IRQ handling is fixed.
49 * app note sbaa036 talks in more detail about accurate sampling...
50 * that ought to help in situations like LCDs inducing noise (which
51 * can also be helped by using synch signals) and more generally.
52 * This driver tries to utilize the measures described in the app
53 * note. The strength of filtering can be set in the board-* specific
57 #define TS_POLL_PERIOD msecs_to_jiffies(10)
59 /* this driver doesn't aim at the peak continuous sample rate */
60 #define SAMPLE_BITS (8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after */)
63 /* For portability, we can't read 12 bit values using SPI (which
64 * would make the controller deliver them as native byteorder u16
65 * with msbs zeroed). Instead, we read them as two 8-bit values,
66 * *** WHICH NEED BYTESWAPPING *** and range adjustment.
75 struct input_dev
*input
;
78 struct spi_device
*spi
;
79 struct attribute_group
*attr_group
;
85 u8 read_x
, read_y
, read_z1
, read_z2
, pwrdown
;
86 u16 dummy
; /* for the pwrdown read */
89 struct spi_transfer xfer
[10];
90 struct spi_message msg
[5];
91 struct spi_message
*last_msg
;
102 struct timer_list timer
; /* P: lock */
103 unsigned pendown
:1; /* P: lock */
104 unsigned pending
:1; /* P: lock */
105 // FIXME remove "irq_disabled"
106 unsigned irq_disabled
:1; /* P: lock */
109 int (*filter
)(void *data
, int data_idx
, int *val
);
111 void (*filter_cleanup
)(void *data
);
112 int (*get_pendown_state
)(void);
115 /* leave chip selected when we're done, for quicker re-select? */
117 #define CS_CHANGE(xfer) ((xfer).cs_change = 1)
119 #define CS_CHANGE(xfer) ((xfer).cs_change = 0)
122 /*--------------------------------------------------------------------------*/
124 /* The ADS7846 has touchscreen and other sensors.
125 * Earlier ads784x chips are somewhat compatible.
127 #define ADS_START (1 << 7)
128 #define ADS_A2A1A0_d_y (1 << 4) /* differential */
129 #define ADS_A2A1A0_d_z1 (3 << 4) /* differential */
130 #define ADS_A2A1A0_d_z2 (4 << 4) /* differential */
131 #define ADS_A2A1A0_d_x (5 << 4) /* differential */
132 #define ADS_A2A1A0_temp0 (0 << 4) /* non-differential */
133 #define ADS_A2A1A0_vbatt (2 << 4) /* non-differential */
134 #define ADS_A2A1A0_vaux (6 << 4) /* non-differential */
135 #define ADS_A2A1A0_temp1 (7 << 4) /* non-differential */
136 #define ADS_8_BIT (1 << 3)
137 #define ADS_12_BIT (0 << 3)
138 #define ADS_SER (1 << 2) /* non-differential */
139 #define ADS_DFR (0 << 2) /* differential */
140 #define ADS_PD10_PDOWN (0 << 0) /* lowpower mode + penirq */
141 #define ADS_PD10_ADC_ON (1 << 0) /* ADC on */
142 #define ADS_PD10_REF_ON (2 << 0) /* vREF on + penirq */
143 #define ADS_PD10_ALL_ON (3 << 0) /* ADC + vREF on */
145 #define MAX_12BIT ((1<<12)-1)
147 /* leave ADC powered up (disables penirq) between differential samples */
148 #define READ_12BIT_DFR(x) (ADS_START | ADS_A2A1A0_d_ ## x \
149 | ADS_12_BIT | ADS_DFR)
151 #define READ_Y (READ_12BIT_DFR(y) | ADS_PD10_ADC_ON)
152 #define READ_Z1 (READ_12BIT_DFR(z1) | ADS_PD10_ADC_ON)
153 #define READ_Z2 (READ_12BIT_DFR(z2) | ADS_PD10_ADC_ON)
155 #define READ_X (READ_12BIT_DFR(x) | ADS_PD10_ADC_ON)
156 #define PWRDOWN (READ_12BIT_DFR(y) | ADS_PD10_PDOWN) /* LAST */
158 /* single-ended samples need to first power up reference voltage;
159 * we leave both ADC and VREF powered
161 #define READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \
162 | ADS_12_BIT | ADS_SER)
164 #define REF_ON (READ_12BIT_DFR(x) | ADS_PD10_ALL_ON)
165 #define REF_OFF (READ_12BIT_DFR(y) | ADS_PD10_PDOWN)
167 /*--------------------------------------------------------------------------*/
170 * Non-touchscreen sensors only use single-ended conversions.
179 struct spi_message msg
;
180 struct spi_transfer xfer
[6];
183 static void ads7846_enable(struct ads7846
*ts
);
184 static void ads7846_disable(struct ads7846
*ts
);
186 static int device_suspended(struct device
*dev
)
188 struct ads7846
*ts
= dev_get_drvdata(dev
);
189 return dev
->power
.power_state
.event
!= PM_EVENT_ON
|| ts
->disabled
;
192 static int ads7846_read12_ser(struct device
*dev
, unsigned command
)
194 struct spi_device
*spi
= to_spi_device(dev
);
195 struct ads7846
*ts
= dev_get_drvdata(dev
);
196 struct ser_req
*req
= kzalloc(sizeof *req
, GFP_KERNEL
);
204 spi_message_init(&req
->msg
);
206 /* activate reference, so it has time to settle; */
207 req
->ref_on
= REF_ON
;
208 req
->xfer
[0].tx_buf
= &req
->ref_on
;
209 req
->xfer
[0].len
= 1;
210 req
->xfer
[1].rx_buf
= &req
->scratch
;
211 req
->xfer
[1].len
= 2;
214 * for external VREF, 0 usec (and assume it's always on);
215 * for 1uF, use 800 usec;
218 req
->xfer
[1].delay_usecs
= ts
->vref_delay_usecs
;
221 req
->command
= (u8
) command
;
222 req
->xfer
[2].tx_buf
= &req
->command
;
223 req
->xfer
[2].len
= 1;
224 req
->xfer
[3].rx_buf
= &req
->sample
;
225 req
->xfer
[3].len
= 2;
227 /* REVISIT: take a few more samples, and compare ... */
229 /* turn off reference */
230 req
->ref_off
= REF_OFF
;
231 req
->xfer
[4].tx_buf
= &req
->ref_off
;
232 req
->xfer
[4].len
= 1;
233 req
->xfer
[5].rx_buf
= &req
->scratch
;
234 req
->xfer
[5].len
= 2;
236 CS_CHANGE(req
->xfer
[5]);
238 /* group all the transfers together, so we can't interfere with
239 * reading touchscreen state; disable penirq while sampling
241 for (i
= 0; i
< 6; i
++)
242 spi_message_add_tail(&req
->xfer
[i
], &req
->msg
);
244 ts
->irq_disabled
= 1;
245 disable_irq(spi
->irq
);
246 status
= spi_sync(spi
, &req
->msg
);
247 ts
->irq_disabled
= 0;
248 enable_irq(spi
->irq
);
251 status
= req
->msg
.status
;
253 /* on-wire is a must-ignore bit, a BE12 value, then padding */
254 sample
= be16_to_cpu(req
->sample
);
255 sample
= sample
>> 3;
259 return status
? status
: sample
;
262 #define SHOW(name) static ssize_t \
263 name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \
265 ssize_t v = ads7846_read12_ser(dev, \
266 READ_12BIT_SER(name) | ADS_PD10_ALL_ON); \
269 return sprintf(buf, "%u\n", (unsigned) v); \
271 static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
278 static int is_pen_down(struct device
*dev
)
280 struct ads7846
*ts
= dev_get_drvdata(dev
);
285 static ssize_t
ads7846_pen_down_show(struct device
*dev
,
286 struct device_attribute
*attr
, char *buf
)
288 return sprintf(buf
, "%u\n", is_pen_down(dev
));
291 static DEVICE_ATTR(pen_down
, S_IRUGO
, ads7846_pen_down_show
, NULL
);
293 static ssize_t
ads7846_disable_show(struct device
*dev
,
294 struct device_attribute
*attr
, char *buf
)
296 struct ads7846
*ts
= dev_get_drvdata(dev
);
298 return sprintf(buf
, "%u\n", ts
->disabled
);
301 static ssize_t
ads7846_disable_store(struct device
*dev
,
302 struct device_attribute
*attr
,
303 const char *buf
, size_t count
)
305 struct ads7846
*ts
= dev_get_drvdata(dev
);
309 i
= simple_strtoul(buf
, &endp
, 10);
310 spin_lock_irq(&ts
->lock
);
317 spin_unlock_irq(&ts
->lock
);
322 static DEVICE_ATTR(disable
, 0664, ads7846_disable_show
, ads7846_disable_store
);
324 static struct attribute
*ads7846_attributes
[] = {
325 &dev_attr_temp0
.attr
,
326 &dev_attr_temp1
.attr
,
327 &dev_attr_vbatt
.attr
,
329 &dev_attr_pen_down
.attr
,
330 &dev_attr_disable
.attr
,
334 static struct attribute_group ads7846_attr_group
= {
335 .attrs
= ads7846_attributes
,
339 * ads7843/7845 don't have temperature sensors, and
340 * use the other sensors a bit differently too
343 static struct attribute
*ads7843_attributes
[] = {
344 &dev_attr_vbatt
.attr
,
346 &dev_attr_pen_down
.attr
,
347 &dev_attr_disable
.attr
,
351 static struct attribute_group ads7843_attr_group
= {
352 .attrs
= ads7843_attributes
,
355 static struct attribute
*ads7845_attributes
[] = {
357 &dev_attr_pen_down
.attr
,
358 &dev_attr_disable
.attr
,
362 static struct attribute_group ads7845_attr_group
= {
363 .attrs
= ads7845_attributes
,
366 /*--------------------------------------------------------------------------*/
369 * PENIRQ only kicks the timer. The timer only reissues the SPI transfer,
370 * to retrieve touchscreen status.
372 * The SPI transfer completion callback does the real work. It reports
373 * touchscreen events and reactivates the timer (or IRQ) as appropriate.
376 static void ads7846_rx(void *ads
)
378 struct ads7846
*ts
= ads
;
379 struct input_dev
*input_dev
= ts
->input
;
385 /* ads7846_rx_val() did in-place conversion (including byteswap) from
386 * on-the-wire format as part of debouncing to get stable readings.
393 /* range filtering */
397 if (likely(x
&& z1
&& !device_suspended(&ts
->spi
->dev
))) {
398 /* compute touch pressure resistance using equation #2 */
402 Rt
*= ts
->x_plate_ohms
;
404 Rt
= (Rt
+ 2047) >> 12;
408 /* Sample found inconsistent by debouncing or pressure is beyond
409 * the maximum. Don't report it to user space, repeat at least
410 * once more the measurement */
411 if (ts
->tc
.ignore
|| Rt
> ts
->pressure_max
) {
412 mod_timer(&ts
->timer
, jiffies
+ TS_POLL_PERIOD
);
416 /* NOTE: "pendown" is inferred from pressure; we don't rely on
417 * being able to check nPENIRQ status, or "friendly" trigger modes
418 * (both-edges is much better than just-falling or low-level).
420 * REVISIT: some boards may require reading nPENIRQ; it's
421 * needed on 7843. and 7845 reads pressure differently...
423 * REVISIT: the touchscreen might not be connected; this code
424 * won't notice that, even if nPENIRQ never fires ...
426 if (!ts
->pendown
&& Rt
!= 0) {
427 input_report_key(input_dev
, BTN_TOUCH
, 1);
429 } else if (ts
->pendown
&& Rt
== 0) {
430 input_report_key(input_dev
, BTN_TOUCH
, 0);
435 input_report_abs(input_dev
, ABS_X
, x
);
436 input_report_abs(input_dev
, ABS_Y
, y
);
441 input_report_abs(input_dev
, ABS_PRESSURE
, Rt
);
442 input_sync(input_dev
);
446 if (Rt
|| ts
->pendown
)
447 pr_debug("%s: %d/%d/%d%s\n", ts
->spi
->dev
.bus_id
,
448 x
, y
, Rt
, Rt
? "" : " UP");
451 spin_lock_irqsave(&ts
->lock
, flags
);
453 ts
->pendown
= (Rt
!= 0);
454 mod_timer(&ts
->timer
, jiffies
+ TS_POLL_PERIOD
);
456 spin_unlock_irqrestore(&ts
->lock
, flags
);
459 static int ads7846_debounce(void *ads
, int data_idx
, int *val
)
461 struct ads7846
*ts
= ads
;
463 if (!ts
->read_cnt
|| (abs(ts
->last_read
- *val
) > ts
->debounce_tol
)) {
464 /* Start over collecting consistent readings. */
466 /* Repeat it, if this was the first read or the read
467 * wasn't consistent enough. */
468 if (ts
->read_cnt
< ts
->debounce_max
) {
469 ts
->last_read
= *val
;
471 return ADS7846_FILTER_REPEAT
;
473 /* Maximum number of debouncing reached and still
474 * not enough number of consistent readings. Abort
475 * the whole sample, repeat it in the next sampling
479 return ADS7846_FILTER_IGNORE
;
482 if (++ts
->read_rep
> ts
->debounce_rep
) {
483 /* Got a good reading for this coordinate,
484 * go for the next one. */
487 return ADS7846_FILTER_OK
;
489 /* Read more values that are consistent. */
491 return ADS7846_FILTER_REPEAT
;
496 static int ads7846_no_filter(void *ads
, int data_idx
, int *val
)
498 return ADS7846_FILTER_OK
;
501 static void ads7846_rx_val(void *ads
)
503 struct ads7846
*ts
= ads
;
504 struct spi_message
*m
;
505 struct spi_transfer
*t
;
511 m
= &ts
->msg
[ts
->msg_idx
];
512 t
= list_entry(m
->transfers
.prev
, struct spi_transfer
, transfer_list
);
515 /* adjust: on-wire is a must-ignore bit, a BE12 value, then padding;
516 * built from two 8 bit values written msb-first.
518 val
= be16_to_cpu(*rx_val
) >> 3;
520 action
= ts
->filter(ts
->filter_data
, ts
->msg_idx
, &val
);
522 case ADS7846_FILTER_REPEAT
:
524 case ADS7846_FILTER_IGNORE
:
526 /* Last message will contain ads7846_rx() as the
527 * completion function.
531 case ADS7846_FILTER_OK
:
534 m
= &ts
->msg
[++ts
->msg_idx
];
539 status
= spi_async(ts
->spi
, m
);
541 dev_err(&ts
->spi
->dev
, "spi_async --> %d\n",
545 static void ads7846_timer(unsigned long handle
)
547 struct ads7846
*ts
= (void *)handle
;
550 spin_lock_irq(&ts
->lock
);
552 if (unlikely(ts
->msg_idx
&& !ts
->pendown
)) {
553 /* measurement cycle ended */
554 if (!device_suspended(&ts
->spi
->dev
)) {
555 ts
->irq_disabled
= 0;
556 enable_irq(ts
->spi
->irq
);
561 /* pen is still down, continue with the measurement */
563 status
= spi_async(ts
->spi
, &ts
->msg
[0]);
565 dev_err(&ts
->spi
->dev
, "spi_async --> %d\n", status
);
568 spin_unlock_irq(&ts
->lock
);
571 static irqreturn_t
ads7846_irq(int irq
, void *handle
)
573 struct ads7846
*ts
= handle
;
576 spin_lock_irqsave(&ts
->lock
, flags
);
577 if (likely(ts
->get_pendown_state())) {
578 if (!ts
->irq_disabled
) {
579 /* The ARM do_simple_IRQ() dispatcher doesn't act
580 * like the other dispatchers: it will report IRQs
581 * even after they've been disabled. We work around
582 * that here. (The "generic irq" framework may help...)
584 ts
->irq_disabled
= 1;
585 disable_irq(ts
->spi
->irq
);
587 mod_timer(&ts
->timer
, jiffies
);
590 spin_unlock_irqrestore(&ts
->lock
, flags
);
595 /*--------------------------------------------------------------------------*/
597 /* Must be called with ts->lock held */
598 static void ads7846_disable(struct ads7846
*ts
)
605 /* are we waiting for IRQ, or polling? */
607 ts
->irq_disabled
= 1;
608 disable_irq(ts
->spi
->irq
);
610 /* the timer will run at least once more, and
611 * leave everything in a clean state, IRQ disabled
613 while (ts
->pending
) {
614 spin_unlock_irq(&ts
->lock
);
616 spin_lock_irq(&ts
->lock
);
620 /* we know the chip's in lowpower mode since we always
621 * leave it that way after every request
626 /* Must be called with ts->lock held */
627 static void ads7846_enable(struct ads7846
*ts
)
633 ts
->irq_disabled
= 0;
634 enable_irq(ts
->spi
->irq
);
637 static int ads7846_suspend(struct spi_device
*spi
, pm_message_t message
)
639 struct ads7846
*ts
= dev_get_drvdata(&spi
->dev
);
641 spin_lock_irq(&ts
->lock
);
643 spi
->dev
.power
.power_state
= message
;
646 spin_unlock_irq(&ts
->lock
);
652 static int ads7846_resume(struct spi_device
*spi
)
654 struct ads7846
*ts
= dev_get_drvdata(&spi
->dev
);
656 spin_lock_irq(&ts
->lock
);
658 spi
->dev
.power
.power_state
= PMSG_ON
;
661 spin_unlock_irq(&ts
->lock
);
666 static int __devinit
ads7846_probe(struct spi_device
*spi
)
669 struct input_dev
*input_dev
;
670 struct ads7846_platform_data
*pdata
= spi
->dev
.platform_data
;
671 struct spi_message
*m
;
672 struct spi_transfer
*x
;
676 dev_dbg(&spi
->dev
, "no IRQ?\n");
681 dev_dbg(&spi
->dev
, "no platform data?\n");
685 /* don't exceed max specified sample rate */
686 if (spi
->max_speed_hz
> (125000 * SAMPLE_BITS
)) {
687 dev_dbg(&spi
->dev
, "f(sample) %d KHz?\n",
688 (spi
->max_speed_hz
/SAMPLE_BITS
)/1000);
692 /* REVISIT when the irq can be triggered active-low, or if for some
693 * reason the touchscreen isn't hooked up, we don't need to access
696 if (pdata
->get_pendown_state
== NULL
) {
697 dev_dbg(&spi
->dev
, "no get_pendown_state function?\n");
701 /* We'd set TX wordsize 8 bits and RX wordsize to 13 bits ... except
702 * that even if the hardware can do that, the SPI controller driver
703 * may not. So we stick to very-portable 8 bit words, both RX and TX.
705 spi
->bits_per_word
= 8;
707 ts
= kzalloc(sizeof(struct ads7846
), GFP_KERNEL
);
708 input_dev
= input_allocate_device();
709 if (!ts
|| !input_dev
) {
714 dev_set_drvdata(&spi
->dev
, ts
);
715 spi
->dev
.power
.power_state
= PMSG_ON
;
718 ts
->input
= input_dev
;
720 init_timer(&ts
->timer
);
721 ts
->timer
.data
= (unsigned long) ts
;
722 ts
->timer
.function
= ads7846_timer
;
724 spin_lock_init(&ts
->lock
);
726 ts
->model
= pdata
->model
? : 7846;
727 ts
->vref_delay_usecs
= pdata
->vref_delay_usecs
? : 100;
728 ts
->x_plate_ohms
= pdata
->x_plate_ohms
? : 400;
729 ts
->pressure_max
= pdata
->pressure_max
? : ~0;
731 if (pdata
->filter
!= NULL
) {
732 if (pdata
->filter_init
!= NULL
) {
733 err
= pdata
->filter_init(pdata
, &ts
->filter_data
);
737 ts
->filter
= pdata
->filter
;
738 ts
->filter_cleanup
= pdata
->filter_cleanup
;
739 } else if (pdata
->debounce_max
) {
740 ts
->debounce_max
= pdata
->debounce_max
;
741 if (ts
->debounce_max
< 2)
742 ts
->debounce_max
= 2;
743 ts
->debounce_tol
= pdata
->debounce_tol
;
744 ts
->debounce_rep
= pdata
->debounce_rep
;
745 ts
->filter
= ads7846_debounce
;
746 ts
->filter_data
= ts
;
748 ts
->filter
= ads7846_no_filter
;
749 ts
->get_pendown_state
= pdata
->get_pendown_state
;
751 snprintf(ts
->phys
, sizeof(ts
->phys
), "%s/input0", spi
->dev
.bus_id
);
753 input_dev
->name
= "ADS784x Touchscreen";
754 input_dev
->phys
= ts
->phys
;
755 input_dev
->cdev
.dev
= &spi
->dev
;
757 input_dev
->evbit
[0] = BIT(EV_KEY
) | BIT(EV_ABS
);
758 input_dev
->keybit
[LONG(BTN_TOUCH
)] = BIT(BTN_TOUCH
);
759 input_set_abs_params(input_dev
, ABS_X
,
761 pdata
->x_max
? : MAX_12BIT
,
763 input_set_abs_params(input_dev
, ABS_Y
,
765 pdata
->y_max
? : MAX_12BIT
,
767 input_set_abs_params(input_dev
, ABS_PRESSURE
,
768 pdata
->pressure_min
, pdata
->pressure_max
, 0, 0);
770 /* set up the transfers to read touchscreen state; this assumes we
771 * use formula #2 for pressure, not #3.
778 /* y- still on; turn on only y+ (and ADC) */
780 x
->tx_buf
= &ts
->read_y
;
782 spi_message_add_tail(x
, m
);
785 x
->rx_buf
= &ts
->tc
.y
;
787 spi_message_add_tail(x
, m
);
789 m
->complete
= ads7846_rx_val
;
795 /* turn y- off, x+ on, then leave in lowpower */
798 x
->tx_buf
= &ts
->read_x
;
800 spi_message_add_tail(x
, m
);
803 x
->rx_buf
= &ts
->tc
.x
;
805 spi_message_add_tail(x
, m
);
807 m
->complete
= ads7846_rx_val
;
810 /* turn y+ off, x- on; we'll use formula #2 */
811 if (ts
->model
== 7846) {
816 ts
->read_z1
= READ_Z1
;
817 x
->tx_buf
= &ts
->read_z1
;
819 spi_message_add_tail(x
, m
);
822 x
->rx_buf
= &ts
->tc
.z1
;
824 spi_message_add_tail(x
, m
);
826 m
->complete
= ads7846_rx_val
;
833 ts
->read_z2
= READ_Z2
;
834 x
->tx_buf
= &ts
->read_z2
;
836 spi_message_add_tail(x
, m
);
839 x
->rx_buf
= &ts
->tc
.z2
;
841 spi_message_add_tail(x
, m
);
843 m
->complete
= ads7846_rx_val
;
852 ts
->pwrdown
= PWRDOWN
;
853 x
->tx_buf
= &ts
->pwrdown
;
855 spi_message_add_tail(x
, m
);
858 x
->rx_buf
= &ts
->dummy
;
861 spi_message_add_tail(x
, m
);
863 m
->complete
= ads7846_rx
;
868 if (request_irq(spi
->irq
, ads7846_irq
, IRQF_TRIGGER_FALLING
,
869 spi
->dev
.driver
->name
, ts
)) {
870 dev_dbg(&spi
->dev
, "irq %d busy?\n", spi
->irq
);
872 goto err_cleanup_filter
;
875 dev_info(&spi
->dev
, "touchscreen, irq %d\n", spi
->irq
);
877 /* take a first sample, leaving nPENIRQ active; avoid
878 * the touchscreen, in case it's not connected.
880 (void) ads7846_read12_ser(&spi
->dev
,
881 READ_12BIT_SER(vaux
) | ADS_PD10_ALL_ON
);
885 ts
->attr_group
= &ads7846_attr_group
;
888 ts
->attr_group
= &ads7845_attr_group
;
891 ts
->attr_group
= &ads7843_attr_group
;
894 err
= sysfs_create_group(&spi
->dev
.kobj
, ts
->attr_group
);
898 err
= input_register_device(input_dev
);
900 goto err_remove_attr_group
;
904 err_remove_attr_group
:
905 sysfs_remove_group(&spi
->dev
.kobj
, ts
->attr_group
);
907 free_irq(spi
->irq
, ts
);
909 if (ts
->filter_cleanup
)
910 ts
->filter_cleanup(ts
->filter_data
);
912 input_free_device(input_dev
);
917 static int __devexit
ads7846_remove(struct spi_device
*spi
)
919 struct ads7846
*ts
= dev_get_drvdata(&spi
->dev
);
921 input_unregister_device(ts
->input
);
923 ads7846_suspend(spi
, PMSG_SUSPEND
);
925 sysfs_remove_group(&spi
->dev
.kobj
, ts
->attr_group
);
927 free_irq(ts
->spi
->irq
, ts
);
928 /* suspend left the IRQ disabled */
929 enable_irq(ts
->spi
->irq
);
931 if (ts
->filter_cleanup
)
932 ts
->filter_cleanup(ts
->filter_data
);
936 dev_dbg(&spi
->dev
, "unregistered touchscreen\n");
940 static struct spi_driver ads7846_driver
= {
943 .bus
= &spi_bus_type
,
944 .owner
= THIS_MODULE
,
946 .probe
= ads7846_probe
,
947 .remove
= __devexit_p(ads7846_remove
),
948 .suspend
= ads7846_suspend
,
949 .resume
= ads7846_resume
,
952 static int __init
ads7846_init(void)
954 /* grr, board-specific init should stay out of drivers!! */
956 #ifdef CONFIG_ARCH_OMAP
957 if (machine_is_omap_osk()) {
958 /* GPIO4 = PENIRQ; GPIO6 = BUSY */
959 omap_request_gpio(4);
960 omap_set_gpio_direction(4, 1);
961 omap_request_gpio(6);
962 omap_set_gpio_direction(6, 1);
964 // also TI 1510 Innovator, bitbanging through FPGA
966 // also Palm Tungsten T2
970 // also Dell Axim X50
971 // also HP iPaq H191x/H192x/H415x/H435x
972 // also Intel Lubbock (additional to UCB1400; as temperature sensor)
973 // also Sharp Zaurus C7xx, C8xx (corgi/sheperd/husky)
975 // Atmel at91sam9261-EK uses ads7843
977 // also various AMD Au1x00 devel boards
979 return spi_register_driver(&ads7846_driver
);
981 module_init(ads7846_init
);
983 static void __exit
ads7846_exit(void)
985 spi_unregister_driver(&ads7846_driver
);
987 #ifdef CONFIG_ARCH_OMAP
988 if (machine_is_omap_osk()) {
995 module_exit(ads7846_exit
);
997 MODULE_DESCRIPTION("ADS7846 TouchScreen Driver");
998 MODULE_LICENSE("GPL");