tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * AD7879/AD7889 based touchscreen and GPIO driver
3 *
4 * Copyright (C) 2008-2010 Michael Hennerich, Analog Devices Inc.
5 *
6 * Licensed under the GPL-2 or later.
7 *
8 * History:
9 * Copyright (c) 2005 David Brownell
10 * Copyright (c) 2006 Nokia Corporation
11 * Various changes: Imre Deak <imre.deak@nokia.com>
12 *
13 * Using code from:
14 * - corgi_ts.c
15 * Copyright (C) 2004-2005 Richard Purdie
16 * - omap_ts.[hc], ads7846.h, ts_osk.c
17 * Copyright (C) 2002 MontaVista Software
18 * Copyright (C) 2004 Texas Instruments
19 * Copyright (C) 2005 Dirk Behme
20 * - ad7877.c
21 * Copyright (C) 2006-2008 Analog Devices Inc.
22 */
23
24#include <linux/device.h>
25#include <linux/init.h>
26#include <linux/delay.h>
27#include <linux/input.h>
28#include <linux/interrupt.h>
29#include <linux/irq.h>
30#include <linux/slab.h>
31#include <linux/spi/spi.h>
32#include <linux/i2c.h>
33#include <linux/gpio.h>
34
35#include <linux/spi/ad7879.h>
36#include "ad7879.h"
37
38#define AD7879_REG_ZEROS 0
39#define AD7879_REG_CTRL1 1
40#define AD7879_REG_CTRL2 2
41#define AD7879_REG_CTRL3 3
42#define AD7879_REG_AUX1HIGH 4
43#define AD7879_REG_AUX1LOW 5
44#define AD7879_REG_TEMP1HIGH 6
45#define AD7879_REG_TEMP1LOW 7
46#define AD7879_REG_XPLUS 8
47#define AD7879_REG_YPLUS 9
48#define AD7879_REG_Z1 10
49#define AD7879_REG_Z2 11
50#define AD7879_REG_AUXVBAT 12
51#define AD7879_REG_TEMP 13
52#define AD7879_REG_REVID 14
53
54/* Control REG 1 */
55#define AD7879_TMR(x) ((x & 0xFF) << 0)
56#define AD7879_ACQ(x) ((x & 0x3) << 8)
57#define AD7879_MODE_NOC (0 << 10) /* Do not convert */
58#define AD7879_MODE_SCC (1 << 10) /* Single channel conversion */
59#define AD7879_MODE_SEQ0 (2 << 10) /* Sequence 0 in Slave Mode */
60#define AD7879_MODE_SEQ1 (3 << 10) /* Sequence 1 in Master Mode */
61#define AD7879_MODE_INT (1 << 15) /* PENIRQ disabled INT enabled */
62
63/* Control REG 2 */
64#define AD7879_FCD(x) ((x & 0x3) << 0)
65#define AD7879_RESET (1 << 4)
66#define AD7879_MFS(x) ((x & 0x3) << 5)
67#define AD7879_AVG(x) ((x & 0x3) << 7)
68#define AD7879_SER (1 << 9) /* non-differential */
69#define AD7879_DFR (0 << 9) /* differential */
70#define AD7879_GPIOPOL (1 << 10)
71#define AD7879_GPIODIR (1 << 11)
72#define AD7879_GPIO_DATA (1 << 12)
73#define AD7879_GPIO_EN (1 << 13)
74#define AD7879_PM(x) ((x & 0x3) << 14)
75#define AD7879_PM_SHUTDOWN (0)
76#define AD7879_PM_DYN (1)
77#define AD7879_PM_FULLON (2)
78
79/* Control REG 3 */
80#define AD7879_TEMPMASK_BIT (1<<15)
81#define AD7879_AUXVBATMASK_BIT (1<<14)
82#define AD7879_INTMODE_BIT (1<<13)
83#define AD7879_GPIOALERTMASK_BIT (1<<12)
84#define AD7879_AUXLOW_BIT (1<<11)
85#define AD7879_AUXHIGH_BIT (1<<10)
86#define AD7879_TEMPLOW_BIT (1<<9)
87#define AD7879_TEMPHIGH_BIT (1<<8)
88#define AD7879_YPLUS_BIT (1<<7)
89#define AD7879_XPLUS_BIT (1<<6)
90#define AD7879_Z1_BIT (1<<5)
91#define AD7879_Z2_BIT (1<<4)
92#define AD7879_AUX_BIT (1<<3)
93#define AD7879_VBAT_BIT (1<<2)
94#define AD7879_TEMP_BIT (1<<1)
95
96enum {
97 AD7879_SEQ_XPOS = 0,
98 AD7879_SEQ_YPOS = 1,
99 AD7879_SEQ_Z1 = 2,
100 AD7879_SEQ_Z2 = 3,
101 AD7879_NR_SENSE = 4,
102};
103
104#define MAX_12BIT ((1<<12)-1)
105#define TS_PEN_UP_TIMEOUT msecs_to_jiffies(50)
106
107struct ad7879 {
108 const struct ad7879_bus_ops *bops;
109
110 struct device *dev;
111 struct input_dev *input;
112 struct timer_list timer;
113#ifdef CONFIG_GPIOLIB
114 struct gpio_chip gc;
115 struct mutex mutex;
116#endif
117 unsigned int irq;
118 bool disabled; /* P: input->mutex */
119 bool suspended; /* P: input->mutex */
120 u16 conversion_data[AD7879_NR_SENSE];
121 char phys[32];
122 u8 first_conversion_delay;
123 u8 acquisition_time;
124 u8 averaging;
125 u8 pen_down_acc_interval;
126 u8 median;
127 u16 x_plate_ohms;
128 u16 pressure_max;
129 u16 cmd_crtl1;
130 u16 cmd_crtl2;
131 u16 cmd_crtl3;
132};
133
134static int ad7879_read(struct ad7879 *ts, u8 reg)
135{
136 return ts->bops->read(ts->dev, reg);
137}
138
139static int ad7879_multi_read(struct ad7879 *ts, u8 first_reg, u8 count, u16 *buf)
140{
141 return ts->bops->multi_read(ts->dev, first_reg, count, buf);
142}
143
144static int ad7879_write(struct ad7879 *ts, u8 reg, u16 val)
145{
146 return ts->bops->write(ts->dev, reg, val);
147}
148
149static int ad7879_report(struct ad7879 *ts)
150{
151 struct input_dev *input_dev = ts->input;
152 unsigned Rt;
153 u16 x, y, z1, z2;
154
155 x = ts->conversion_data[AD7879_SEQ_XPOS] & MAX_12BIT;
156 y = ts->conversion_data[AD7879_SEQ_YPOS] & MAX_12BIT;
157 z1 = ts->conversion_data[AD7879_SEQ_Z1] & MAX_12BIT;
158 z2 = ts->conversion_data[AD7879_SEQ_Z2] & MAX_12BIT;
159
160 /*
161 * The samples processed here are already preprocessed by the AD7879.
162 * The preprocessing function consists of a median and an averaging
163 * filter. The combination of these two techniques provides a robust
164 * solution, discarding the spurious noise in the signal and keeping
165 * only the data of interest. The size of both filters is
166 * programmable. (dev.platform_data, see linux/spi/ad7879.h) Other
167 * user-programmable conversion controls include variable acquisition
168 * time, and first conversion delay. Up to 16 averages can be taken
169 * per conversion.
170 */
171
172 if (likely(x && z1)) {
173 /* compute touch pressure resistance using equation #1 */
174 Rt = (z2 - z1) * x * ts->x_plate_ohms;
175 Rt /= z1;
176 Rt = (Rt + 2047) >> 12;
177
178 if (!timer_pending(&ts->timer))
179 input_report_key(input_dev, BTN_TOUCH, 1);
180
181 input_report_abs(input_dev, ABS_X, x);
182 input_report_abs(input_dev, ABS_Y, y);
183 input_report_abs(input_dev, ABS_PRESSURE, Rt);
184 input_sync(input_dev);
185 return 0;
186 }
187
188 return -EINVAL;
189}
190
191static void ad7879_ts_event_release(struct ad7879 *ts)
192{
193 struct input_dev *input_dev = ts->input;
194
195 input_report_abs(input_dev, ABS_PRESSURE, 0);
196 input_report_key(input_dev, BTN_TOUCH, 0);
197 input_sync(input_dev);
198}
199
200static void ad7879_timer(unsigned long handle)
201{
202 struct ad7879 *ts = (void *)handle;
203
204 ad7879_ts_event_release(ts);
205}
206
207static irqreturn_t ad7879_irq(int irq, void *handle)
208{
209 struct ad7879 *ts = handle;
210
211 ad7879_multi_read(ts, AD7879_REG_XPLUS, AD7879_NR_SENSE, ts->conversion_data);
212
213 if (!ad7879_report(ts))
214 mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
215
216 return IRQ_HANDLED;
217}
218
219static void __ad7879_enable(struct ad7879 *ts)
220{
221 ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
222 ad7879_write(ts, AD7879_REG_CTRL3, ts->cmd_crtl3);
223 ad7879_write(ts, AD7879_REG_CTRL1, ts->cmd_crtl1);
224
225 enable_irq(ts->irq);
226}
227
228static void __ad7879_disable(struct ad7879 *ts)
229{
230 disable_irq(ts->irq);
231
232 if (del_timer_sync(&ts->timer))
233 ad7879_ts_event_release(ts);
234
235 ad7879_write(ts, AD7879_REG_CTRL2, AD7879_PM(AD7879_PM_SHUTDOWN));
236}
237
238
239static int ad7879_open(struct input_dev *input)
240{
241 struct ad7879 *ts = input_get_drvdata(input);
242
243 /* protected by input->mutex */
244 if (!ts->disabled && !ts->suspended)
245 __ad7879_enable(ts);
246
247 return 0;
248}
249
250static void ad7879_close(struct input_dev* input)
251{
252 struct ad7879 *ts = input_get_drvdata(input);
253
254 /* protected by input->mutex */
255 if (!ts->disabled && !ts->suspended)
256 __ad7879_disable(ts);
257}
258
259void ad7879_suspend(struct ad7879 *ts)
260{
261 mutex_lock(&ts->input->mutex);
262
263 if (!ts->suspended && !ts->disabled && ts->input->users)
264 __ad7879_disable(ts);
265
266 ts->suspended = true;
267
268 mutex_unlock(&ts->input->mutex);
269}
270EXPORT_SYMBOL(ad7879_suspend);
271
272void ad7879_resume(struct ad7879 *ts)
273{
274 mutex_lock(&ts->input->mutex);
275
276 if (ts->suspended && !ts->disabled && ts->input->users)
277 __ad7879_enable(ts);
278
279 ts->suspended = false;
280
281 mutex_unlock(&ts->input->mutex);
282}
283EXPORT_SYMBOL(ad7879_resume);
284
285static void ad7879_toggle(struct ad7879 *ts, bool disable)
286{
287 mutex_lock(&ts->input->mutex);
288
289 if (!ts->suspended && ts->input->users != 0) {
290
291 if (disable) {
292 if (ts->disabled)
293 __ad7879_enable(ts);
294 } else {
295 if (!ts->disabled)
296 __ad7879_disable(ts);
297 }
298 }
299
300 ts->disabled = disable;
301
302 mutex_unlock(&ts->input->mutex);
303}
304
305static ssize_t ad7879_disable_show(struct device *dev,
306 struct device_attribute *attr, char *buf)
307{
308 struct ad7879 *ts = dev_get_drvdata(dev);
309
310 return sprintf(buf, "%u\n", ts->disabled);
311}
312
313static ssize_t ad7879_disable_store(struct device *dev,
314 struct device_attribute *attr,
315 const char *buf, size_t count)
316{
317 struct ad7879 *ts = dev_get_drvdata(dev);
318 unsigned long val;
319 int error;
320
321 error = strict_strtoul(buf, 10, &val);
322 if (error)
323 return error;
324
325 ad7879_toggle(ts, val);
326
327 return count;
328}
329
330static DEVICE_ATTR(disable, 0664, ad7879_disable_show, ad7879_disable_store);
331
332static struct attribute *ad7879_attributes[] = {
333 &dev_attr_disable.attr,
334 NULL
335};
336
337static const struct attribute_group ad7879_attr_group = {
338 .attrs = ad7879_attributes,
339};
340
341#ifdef CONFIG_GPIOLIB
342static int ad7879_gpio_direction_input(struct gpio_chip *chip,
343 unsigned gpio)
344{
345 struct ad7879 *ts = container_of(chip, struct ad7879, gc);
346 int err;
347
348 mutex_lock(&ts->mutex);
349 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIODIR | AD7879_GPIOPOL;
350 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
351 mutex_unlock(&ts->mutex);
352
353 return err;
354}
355
356static int ad7879_gpio_direction_output(struct gpio_chip *chip,
357 unsigned gpio, int level)
358{
359 struct ad7879 *ts = container_of(chip, struct ad7879, gc);
360 int err;
361
362 mutex_lock(&ts->mutex);
363 ts->cmd_crtl2 &= ~AD7879_GPIODIR;
364 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIOPOL;
365 if (level)
366 ts->cmd_crtl2 |= AD7879_GPIO_DATA;
367 else
368 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
369
370 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
371 mutex_unlock(&ts->mutex);
372
373 return err;
374}
375
376static int ad7879_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
377{
378 struct ad7879 *ts = container_of(chip, struct ad7879, gc);
379 u16 val;
380
381 mutex_lock(&ts->mutex);
382 val = ad7879_read(ts, AD7879_REG_CTRL2);
383 mutex_unlock(&ts->mutex);
384
385 return !!(val & AD7879_GPIO_DATA);
386}
387
388static void ad7879_gpio_set_value(struct gpio_chip *chip,
389 unsigned gpio, int value)
390{
391 struct ad7879 *ts = container_of(chip, struct ad7879, gc);
392
393 mutex_lock(&ts->mutex);
394 if (value)
395 ts->cmd_crtl2 |= AD7879_GPIO_DATA;
396 else
397 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
398
399 ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
400 mutex_unlock(&ts->mutex);
401}
402
403static int ad7879_gpio_add(struct ad7879 *ts,
404 const struct ad7879_platform_data *pdata)
405{
406 int ret = 0;
407
408 mutex_init(&ts->mutex);
409
410 if (pdata->gpio_export) {
411 ts->gc.direction_input = ad7879_gpio_direction_input;
412 ts->gc.direction_output = ad7879_gpio_direction_output;
413 ts->gc.get = ad7879_gpio_get_value;
414 ts->gc.set = ad7879_gpio_set_value;
415 ts->gc.can_sleep = 1;
416 ts->gc.base = pdata->gpio_base;
417 ts->gc.ngpio = 1;
418 ts->gc.label = "AD7879-GPIO";
419 ts->gc.owner = THIS_MODULE;
420 ts->gc.dev = ts->dev;
421
422 ret = gpiochip_add(&ts->gc);
423 if (ret)
424 dev_err(ts->dev, "failed to register gpio %d\n",
425 ts->gc.base);
426 }
427
428 return ret;
429}
430
431static void ad7879_gpio_remove(struct ad7879 *ts)
432{
433 const struct ad7879_platform_data *pdata = ts->dev->platform_data;
434 int ret;
435
436 if (pdata->gpio_export) {
437 ret = gpiochip_remove(&ts->gc);
438 if (ret)
439 dev_err(ts->dev, "failed to remove gpio %d\n",
440 ts->gc.base);
441 }
442}
443#else
444static inline int ad7879_gpio_add(struct ad7879 *ts,
445 const struct ad7879_platform_data *pdata)
446{
447 return 0;
448}
449
450static inline void ad7879_gpio_remove(struct ad7879 *ts)
451{
452}
453#endif
454
455struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned int irq,
456 const struct ad7879_bus_ops *bops)
457{
458 struct ad7879_platform_data *pdata = dev->platform_data;
459 struct ad7879 *ts;
460 struct input_dev *input_dev;
461 int err;
462 u16 revid;
463
464 if (!irq) {
465 dev_err(dev, "no IRQ?\n");
466 err = -EINVAL;
467 goto err_out;
468 }
469
470 if (!pdata) {
471 dev_err(dev, "no platform data?\n");
472 err = -EINVAL;
473 goto err_out;
474 }
475
476 ts = kzalloc(sizeof(*ts), GFP_KERNEL);
477 input_dev = input_allocate_device();
478 if (!ts || !input_dev) {
479 err = -ENOMEM;
480 goto err_free_mem;
481 }
482
483 ts->bops = bops;
484 ts->dev = dev;
485 ts->input = input_dev;
486 ts->irq = irq;
487
488 setup_timer(&ts->timer, ad7879_timer, (unsigned long) ts);
489
490 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
491 ts->pressure_max = pdata->pressure_max ? : ~0;
492
493 ts->first_conversion_delay = pdata->first_conversion_delay;
494 ts->acquisition_time = pdata->acquisition_time;
495 ts->averaging = pdata->averaging;
496 ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
497 ts->median = pdata->median;
498
499 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));
500
501 input_dev->name = "AD7879 Touchscreen";
502 input_dev->phys = ts->phys;
503 input_dev->dev.parent = dev;
504 input_dev->id.bustype = bops->bustype;
505
506 input_dev->open = ad7879_open;
507 input_dev->close = ad7879_close;
508
509 input_set_drvdata(input_dev, ts);
510
511 __set_bit(EV_ABS, input_dev->evbit);
512 __set_bit(ABS_X, input_dev->absbit);
513 __set_bit(ABS_Y, input_dev->absbit);
514 __set_bit(ABS_PRESSURE, input_dev->absbit);
515
516 __set_bit(EV_KEY, input_dev->evbit);
517 __set_bit(BTN_TOUCH, input_dev->keybit);
518
519 input_set_abs_params(input_dev, ABS_X,
520 pdata->x_min ? : 0,
521 pdata->x_max ? : MAX_12BIT,
522 0, 0);
523 input_set_abs_params(input_dev, ABS_Y,
524 pdata->y_min ? : 0,
525 pdata->y_max ? : MAX_12BIT,
526 0, 0);
527 input_set_abs_params(input_dev, ABS_PRESSURE,
528 pdata->pressure_min, pdata->pressure_max, 0, 0);
529
530 err = ad7879_write(ts, AD7879_REG_CTRL2, AD7879_RESET);
531 if (err < 0) {
532 dev_err(dev, "Failed to write %s\n", input_dev->name);
533 goto err_free_mem;
534 }
535
536 revid = ad7879_read(ts, AD7879_REG_REVID);
537 input_dev->id.product = (revid & 0xff);
538 input_dev->id.version = revid >> 8;
539 if (input_dev->id.product != devid) {
540 dev_err(dev, "Failed to probe %s (%x vs %x)\n",
541 input_dev->name, devid, revid);
542 err = -ENODEV;
543 goto err_free_mem;
544 }
545
546 ts->cmd_crtl3 = AD7879_YPLUS_BIT |
547 AD7879_XPLUS_BIT |
548 AD7879_Z2_BIT |
549 AD7879_Z1_BIT |
550 AD7879_TEMPMASK_BIT |
551 AD7879_AUXVBATMASK_BIT |
552 AD7879_GPIOALERTMASK_BIT;
553
554 ts->cmd_crtl2 = AD7879_PM(AD7879_PM_DYN) | AD7879_DFR |
555 AD7879_AVG(ts->averaging) |
556 AD7879_MFS(ts->median) |
557 AD7879_FCD(ts->first_conversion_delay);
558
559 ts->cmd_crtl1 = AD7879_MODE_INT | AD7879_MODE_SEQ1 |
560 AD7879_ACQ(ts->acquisition_time) |
561 AD7879_TMR(ts->pen_down_acc_interval);
562
563 err = request_threaded_irq(ts->irq, NULL, ad7879_irq,
564 IRQF_TRIGGER_FALLING,
565 dev_name(dev), ts);
566 if (err) {
567 dev_err(dev, "irq %d busy?\n", ts->irq);
568 goto err_free_mem;
569 }
570
571 __ad7879_disable(ts);
572
573 err = sysfs_create_group(&dev->kobj, &ad7879_attr_group);
574 if (err)
575 goto err_free_irq;
576
577 err = ad7879_gpio_add(ts, pdata);
578 if (err)
579 goto err_remove_attr;
580
581 err = input_register_device(input_dev);
582 if (err)
583 goto err_remove_gpio;
584
585 return ts;
586
587err_remove_gpio:
588 ad7879_gpio_remove(ts);
589err_remove_attr:
590 sysfs_remove_group(&dev->kobj, &ad7879_attr_group);
591err_free_irq:
592 free_irq(ts->irq, ts);
593err_free_mem:
594 input_free_device(input_dev);
595 kfree(ts);
596err_out:
597 return ERR_PTR(err);
598}
599EXPORT_SYMBOL(ad7879_probe);
600
601void ad7879_remove(struct ad7879 *ts)
602{
603 ad7879_gpio_remove(ts);
604 sysfs_remove_group(&ts->dev->kobj, &ad7879_attr_group);
605 free_irq(ts->irq, ts);
606 input_unregister_device(ts->input);
607 kfree(ts);
608}
609EXPORT_SYMBOL(ad7879_remove);
610
611MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
612MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver");
613MODULE_LICENSE("GPL");