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24#include <linux/device.h>
25#include <linux/delay.h>
26#include <linux/input.h>
27#include <linux/interrupt.h>
28#include <linux/irq.h>
29#include <linux/slab.h>
30#include <linux/spi/spi.h>
31#include <linux/i2c.h>
32#include <linux/gpio.h>
33
34#include <linux/spi/ad7879.h>
35#include <linux/module.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
55#define AD7879_TMR(x) ((x & 0xFF) << 0)
56#define AD7879_ACQ(x) ((x & 0x3) << 8)
57#define AD7879_MODE_NOC (0 << 10)
58#define AD7879_MODE_SCC (1 << 10)
59#define AD7879_MODE_SEQ0 (2 << 10)
60#define AD7879_MODE_SEQ1 (3 << 10)
61#define AD7879_MODE_INT (1 << 15)
62
63
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)
69#define AD7879_DFR (0 << 9)
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
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;
119 bool suspended;
120 bool swap_xy;
121 u16 conversion_data[AD7879_NR_SENSE];
122 char phys[32];
123 u8 first_conversion_delay;
124 u8 acquisition_time;
125 u8 averaging;
126 u8 pen_down_acc_interval;
127 u8 median;
128 u16 x_plate_ohms;
129 u16 pressure_max;
130 u16 cmd_crtl1;
131 u16 cmd_crtl2;
132 u16 cmd_crtl3;
133 int x;
134 int y;
135 int Rt;
136};
137
138static int ad7879_read(struct ad7879 *ts, u8 reg)
139{
140 return ts->bops->read(ts->dev, reg);
141}
142
143static int ad7879_multi_read(struct ad7879 *ts, u8 first_reg, u8 count, u16 *buf)
144{
145 return ts->bops->multi_read(ts->dev, first_reg, count, buf);
146}
147
148static int ad7879_write(struct ad7879 *ts, u8 reg, u16 val)
149{
150 return ts->bops->write(ts->dev, reg, val);
151}
152
153static int ad7879_report(struct ad7879 *ts)
154{
155 struct input_dev *input_dev = ts->input;
156 unsigned Rt;
157 u16 x, y, z1, z2;
158
159 x = ts->conversion_data[AD7879_SEQ_XPOS] & MAX_12BIT;
160 y = ts->conversion_data[AD7879_SEQ_YPOS] & MAX_12BIT;
161 z1 = ts->conversion_data[AD7879_SEQ_Z1] & MAX_12BIT;
162 z2 = ts->conversion_data[AD7879_SEQ_Z2] & MAX_12BIT;
163
164 if (ts->swap_xy)
165 swap(x, y);
166
167
168
169
170
171
172
173
174
175
176
177
178
179 if (likely(x && z1)) {
180
181 Rt = (z2 - z1) * x * ts->x_plate_ohms;
182 Rt /= z1;
183 Rt = (Rt + 2047) >> 12;
184
185
186
187
188
189 if (Rt > ts->pressure_max)
190 return -EINVAL;
191
192
193
194
195
196
197
198 if (timer_pending(&ts->timer)) {
199
200 input_report_key(input_dev, BTN_TOUCH, 1);
201 input_report_abs(input_dev, ABS_X, ts->x);
202 input_report_abs(input_dev, ABS_Y, ts->y);
203 input_report_abs(input_dev, ABS_PRESSURE, ts->Rt);
204 input_sync(input_dev);
205 }
206
207 ts->x = x;
208 ts->y = y;
209 ts->Rt = Rt;
210
211 return 0;
212 }
213
214 return -EINVAL;
215}
216
217static void ad7879_ts_event_release(struct ad7879 *ts)
218{
219 struct input_dev *input_dev = ts->input;
220
221 input_report_abs(input_dev, ABS_PRESSURE, 0);
222 input_report_key(input_dev, BTN_TOUCH, 0);
223 input_sync(input_dev);
224}
225
226static void ad7879_timer(unsigned long handle)
227{
228 struct ad7879 *ts = (void *)handle;
229
230 ad7879_ts_event_release(ts);
231}
232
233static irqreturn_t ad7879_irq(int irq, void *handle)
234{
235 struct ad7879 *ts = handle;
236
237 ad7879_multi_read(ts, AD7879_REG_XPLUS, AD7879_NR_SENSE, ts->conversion_data);
238
239 if (!ad7879_report(ts))
240 mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
241
242 return IRQ_HANDLED;
243}
244
245static void __ad7879_enable(struct ad7879 *ts)
246{
247 ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
248 ad7879_write(ts, AD7879_REG_CTRL3, ts->cmd_crtl3);
249 ad7879_write(ts, AD7879_REG_CTRL1, ts->cmd_crtl1);
250
251 enable_irq(ts->irq);
252}
253
254static void __ad7879_disable(struct ad7879 *ts)
255{
256 u16 reg = (ts->cmd_crtl2 & ~AD7879_PM(-1)) |
257 AD7879_PM(AD7879_PM_SHUTDOWN);
258 disable_irq(ts->irq);
259
260 if (del_timer_sync(&ts->timer))
261 ad7879_ts_event_release(ts);
262
263 ad7879_write(ts, AD7879_REG_CTRL2, reg);
264}
265
266
267static int ad7879_open(struct input_dev *input)
268{
269 struct ad7879 *ts = input_get_drvdata(input);
270
271
272 if (!ts->disabled && !ts->suspended)
273 __ad7879_enable(ts);
274
275 return 0;
276}
277
278static void ad7879_close(struct input_dev* input)
279{
280 struct ad7879 *ts = input_get_drvdata(input);
281
282
283 if (!ts->disabled && !ts->suspended)
284 __ad7879_disable(ts);
285}
286
287#ifdef CONFIG_PM_SLEEP
288static int ad7879_suspend(struct device *dev)
289{
290 struct ad7879 *ts = dev_get_drvdata(dev);
291
292 mutex_lock(&ts->input->mutex);
293
294 if (!ts->suspended && !ts->disabled && ts->input->users)
295 __ad7879_disable(ts);
296
297 ts->suspended = true;
298
299 mutex_unlock(&ts->input->mutex);
300
301 return 0;
302}
303
304static int ad7879_resume(struct device *dev)
305{
306 struct ad7879 *ts = dev_get_drvdata(dev);
307
308 mutex_lock(&ts->input->mutex);
309
310 if (ts->suspended && !ts->disabled && ts->input->users)
311 __ad7879_enable(ts);
312
313 ts->suspended = false;
314
315 mutex_unlock(&ts->input->mutex);
316
317 return 0;
318}
319#endif
320
321SIMPLE_DEV_PM_OPS(ad7879_pm_ops, ad7879_suspend, ad7879_resume);
322EXPORT_SYMBOL(ad7879_pm_ops);
323
324static void ad7879_toggle(struct ad7879 *ts, bool disable)
325{
326 mutex_lock(&ts->input->mutex);
327
328 if (!ts->suspended && ts->input->users != 0) {
329
330 if (disable) {
331 if (ts->disabled)
332 __ad7879_enable(ts);
333 } else {
334 if (!ts->disabled)
335 __ad7879_disable(ts);
336 }
337 }
338
339 ts->disabled = disable;
340
341 mutex_unlock(&ts->input->mutex);
342}
343
344static ssize_t ad7879_disable_show(struct device *dev,
345 struct device_attribute *attr, char *buf)
346{
347 struct ad7879 *ts = dev_get_drvdata(dev);
348
349 return sprintf(buf, "%u\n", ts->disabled);
350}
351
352static ssize_t ad7879_disable_store(struct device *dev,
353 struct device_attribute *attr,
354 const char *buf, size_t count)
355{
356 struct ad7879 *ts = dev_get_drvdata(dev);
357 unsigned int val;
358 int error;
359
360 error = kstrtouint(buf, 10, &val);
361 if (error)
362 return error;
363
364 ad7879_toggle(ts, val);
365
366 return count;
367}
368
369static DEVICE_ATTR(disable, 0664, ad7879_disable_show, ad7879_disable_store);
370
371static struct attribute *ad7879_attributes[] = {
372 &dev_attr_disable.attr,
373 NULL
374};
375
376static const struct attribute_group ad7879_attr_group = {
377 .attrs = ad7879_attributes,
378};
379
380#ifdef CONFIG_GPIOLIB
381static int ad7879_gpio_direction_input(struct gpio_chip *chip,
382 unsigned gpio)
383{
384 struct ad7879 *ts = container_of(chip, struct ad7879, gc);
385 int err;
386
387 mutex_lock(&ts->mutex);
388 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIODIR | AD7879_GPIOPOL;
389 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
390 mutex_unlock(&ts->mutex);
391
392 return err;
393}
394
395static int ad7879_gpio_direction_output(struct gpio_chip *chip,
396 unsigned gpio, int level)
397{
398 struct ad7879 *ts = container_of(chip, struct ad7879, gc);
399 int err;
400
401 mutex_lock(&ts->mutex);
402 ts->cmd_crtl2 &= ~AD7879_GPIODIR;
403 ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIOPOL;
404 if (level)
405 ts->cmd_crtl2 |= AD7879_GPIO_DATA;
406 else
407 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
408
409 err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
410 mutex_unlock(&ts->mutex);
411
412 return err;
413}
414
415static int ad7879_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
416{
417 struct ad7879 *ts = container_of(chip, struct ad7879, gc);
418 u16 val;
419
420 mutex_lock(&ts->mutex);
421 val = ad7879_read(ts, AD7879_REG_CTRL2);
422 mutex_unlock(&ts->mutex);
423
424 return !!(val & AD7879_GPIO_DATA);
425}
426
427static void ad7879_gpio_set_value(struct gpio_chip *chip,
428 unsigned gpio, int value)
429{
430 struct ad7879 *ts = container_of(chip, struct ad7879, gc);
431
432 mutex_lock(&ts->mutex);
433 if (value)
434 ts->cmd_crtl2 |= AD7879_GPIO_DATA;
435 else
436 ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
437
438 ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
439 mutex_unlock(&ts->mutex);
440}
441
442static int ad7879_gpio_add(struct ad7879 *ts,
443 const struct ad7879_platform_data *pdata)
444{
445 int ret = 0;
446
447 mutex_init(&ts->mutex);
448
449 if (pdata->gpio_export) {
450 ts->gc.direction_input = ad7879_gpio_direction_input;
451 ts->gc.direction_output = ad7879_gpio_direction_output;
452 ts->gc.get = ad7879_gpio_get_value;
453 ts->gc.set = ad7879_gpio_set_value;
454 ts->gc.can_sleep = 1;
455 ts->gc.base = pdata->gpio_base;
456 ts->gc.ngpio = 1;
457 ts->gc.label = "AD7879-GPIO";
458 ts->gc.owner = THIS_MODULE;
459 ts->gc.dev = ts->dev;
460
461 ret = gpiochip_add(&ts->gc);
462 if (ret)
463 dev_err(ts->dev, "failed to register gpio %d\n",
464 ts->gc.base);
465 }
466
467 return ret;
468}
469
470static void ad7879_gpio_remove(struct ad7879 *ts)
471{
472 const struct ad7879_platform_data *pdata = dev_get_platdata(ts->dev);
473
474 if (pdata->gpio_export)
475 gpiochip_remove(&ts->gc);
476
477}
478#else
479static inline int ad7879_gpio_add(struct ad7879 *ts,
480 const struct ad7879_platform_data *pdata)
481{
482 return 0;
483}
484
485static inline void ad7879_gpio_remove(struct ad7879 *ts)
486{
487}
488#endif
489
490struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned int irq,
491 const struct ad7879_bus_ops *bops)
492{
493 struct ad7879_platform_data *pdata = dev_get_platdata(dev);
494 struct ad7879 *ts;
495 struct input_dev *input_dev;
496 int err;
497 u16 revid;
498
499 if (!irq) {
500 dev_err(dev, "no IRQ?\n");
501 err = -EINVAL;
502 goto err_out;
503 }
504
505 if (!pdata) {
506 dev_err(dev, "no platform data?\n");
507 err = -EINVAL;
508 goto err_out;
509 }
510
511 ts = kzalloc(sizeof(*ts), GFP_KERNEL);
512 input_dev = input_allocate_device();
513 if (!ts || !input_dev) {
514 err = -ENOMEM;
515 goto err_free_mem;
516 }
517
518 ts->bops = bops;
519 ts->dev = dev;
520 ts->input = input_dev;
521 ts->irq = irq;
522 ts->swap_xy = pdata->swap_xy;
523
524 setup_timer(&ts->timer, ad7879_timer, (unsigned long) ts);
525
526 ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
527 ts->pressure_max = pdata->pressure_max ? : ~0;
528
529 ts->first_conversion_delay = pdata->first_conversion_delay;
530 ts->acquisition_time = pdata->acquisition_time;
531 ts->averaging = pdata->averaging;
532 ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
533 ts->median = pdata->median;
534
535 snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));
536
537 input_dev->name = "AD7879 Touchscreen";
538 input_dev->phys = ts->phys;
539 input_dev->dev.parent = dev;
540 input_dev->id.bustype = bops->bustype;
541
542 input_dev->open = ad7879_open;
543 input_dev->close = ad7879_close;
544
545 input_set_drvdata(input_dev, ts);
546
547 __set_bit(EV_ABS, input_dev->evbit);
548 __set_bit(ABS_X, input_dev->absbit);
549 __set_bit(ABS_Y, input_dev->absbit);
550 __set_bit(ABS_PRESSURE, input_dev->absbit);
551
552 __set_bit(EV_KEY, input_dev->evbit);
553 __set_bit(BTN_TOUCH, input_dev->keybit);
554
555 input_set_abs_params(input_dev, ABS_X,
556 pdata->x_min ? : 0,
557 pdata->x_max ? : MAX_12BIT,
558 0, 0);
559 input_set_abs_params(input_dev, ABS_Y,
560 pdata->y_min ? : 0,
561 pdata->y_max ? : MAX_12BIT,
562 0, 0);
563 input_set_abs_params(input_dev, ABS_PRESSURE,
564 pdata->pressure_min, pdata->pressure_max, 0, 0);
565
566 err = ad7879_write(ts, AD7879_REG_CTRL2, AD7879_RESET);
567 if (err < 0) {
568 dev_err(dev, "Failed to write %s\n", input_dev->name);
569 goto err_free_mem;
570 }
571
572 revid = ad7879_read(ts, AD7879_REG_REVID);
573 input_dev->id.product = (revid & 0xff);
574 input_dev->id.version = revid >> 8;
575 if (input_dev->id.product != devid) {
576 dev_err(dev, "Failed to probe %s (%x vs %x)\n",
577 input_dev->name, devid, revid);
578 err = -ENODEV;
579 goto err_free_mem;
580 }
581
582 ts->cmd_crtl3 = AD7879_YPLUS_BIT |
583 AD7879_XPLUS_BIT |
584 AD7879_Z2_BIT |
585 AD7879_Z1_BIT |
586 AD7879_TEMPMASK_BIT |
587 AD7879_AUXVBATMASK_BIT |
588 AD7879_GPIOALERTMASK_BIT;
589
590 ts->cmd_crtl2 = AD7879_PM(AD7879_PM_DYN) | AD7879_DFR |
591 AD7879_AVG(ts->averaging) |
592 AD7879_MFS(ts->median) |
593 AD7879_FCD(ts->first_conversion_delay);
594
595 ts->cmd_crtl1 = AD7879_MODE_INT | AD7879_MODE_SEQ1 |
596 AD7879_ACQ(ts->acquisition_time) |
597 AD7879_TMR(ts->pen_down_acc_interval);
598
599 err = request_threaded_irq(ts->irq, NULL, ad7879_irq,
600 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
601 dev_name(dev), ts);
602 if (err) {
603 dev_err(dev, "irq %d busy?\n", ts->irq);
604 goto err_free_mem;
605 }
606
607 __ad7879_disable(ts);
608
609 err = sysfs_create_group(&dev->kobj, &ad7879_attr_group);
610 if (err)
611 goto err_free_irq;
612
613 err = ad7879_gpio_add(ts, pdata);
614 if (err)
615 goto err_remove_attr;
616
617 err = input_register_device(input_dev);
618 if (err)
619 goto err_remove_gpio;
620
621 return ts;
622
623err_remove_gpio:
624 ad7879_gpio_remove(ts);
625err_remove_attr:
626 sysfs_remove_group(&dev->kobj, &ad7879_attr_group);
627err_free_irq:
628 free_irq(ts->irq, ts);
629err_free_mem:
630 input_free_device(input_dev);
631 kfree(ts);
632err_out:
633 return ERR_PTR(err);
634}
635EXPORT_SYMBOL(ad7879_probe);
636
637void ad7879_remove(struct ad7879 *ts)
638{
639 ad7879_gpio_remove(ts);
640 sysfs_remove_group(&ts->dev->kobj, &ad7879_attr_group);
641 free_irq(ts->irq, ts);
642 input_unregister_device(ts->input);
643 kfree(ts);
644}
645EXPORT_SYMBOL(ad7879_remove);
646
647MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
648MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver");
649MODULE_LICENSE("GPL");
650
