summaryrefslogtreecommitdiff
path: root/arch/blackfin/kernel/bfin_gpio.c
blob: 8cefed8cf5d9d771d470674b48ed77132db1f2e5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
/*
 * File:         arch/blackfin/kernel/bfin_gpio.c
 * Based on:
 * Author:       Michael Hennerich (hennerich@blackfin.uclinux.org)
 *
 * Created:
 * Description:  GPIO Abstraction Layer
 *
 * Modified:
 *               Copyright 2006 Analog Devices Inc.
 *
 * Bugs:         Enter bugs at http://blackfin.uclinux.org/
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see the file COPYING, or write
 * to the Free Software Foundation, Inc.,
 * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

/*
*  Number     BF537/6/4    BF561    BF533/2/1
*
*  GPIO_0       PF0         PF0        PF0
*  GPIO_1       PF1         PF1        PF1
*  GPIO_2       PF2         PF2        PF2
*  GPIO_3       PF3         PF3        PF3
*  GPIO_4       PF4         PF4        PF4
*  GPIO_5       PF5         PF5        PF5
*  GPIO_6       PF6         PF6        PF6
*  GPIO_7       PF7         PF7        PF7
*  GPIO_8       PF8         PF8        PF8
*  GPIO_9       PF9         PF9        PF9
*  GPIO_10      PF10        PF10       PF10
*  GPIO_11      PF11        PF11       PF11
*  GPIO_12      PF12        PF12       PF12
*  GPIO_13      PF13        PF13       PF13
*  GPIO_14      PF14        PF14       PF14
*  GPIO_15      PF15        PF15       PF15
*  GPIO_16      PG0         PF16
*  GPIO_17      PG1         PF17
*  GPIO_18      PG2         PF18
*  GPIO_19      PG3         PF19
*  GPIO_20      PG4         PF20
*  GPIO_21      PG5         PF21
*  GPIO_22      PG6         PF22
*  GPIO_23      PG7         PF23
*  GPIO_24      PG8         PF24
*  GPIO_25      PG9         PF25
*  GPIO_26      PG10        PF26
*  GPIO_27      PG11        PF27
*  GPIO_28      PG12        PF28
*  GPIO_29      PG13        PF29
*  GPIO_30      PG14        PF30
*  GPIO_31      PG15        PF31
*  GPIO_32      PH0         PF32
*  GPIO_33      PH1         PF33
*  GPIO_34      PH2         PF34
*  GPIO_35      PH3         PF35
*  GPIO_36      PH4         PF36
*  GPIO_37      PH5         PF37
*  GPIO_38      PH6         PF38
*  GPIO_39      PH7         PF39
*  GPIO_40      PH8         PF40
*  GPIO_41      PH9         PF41
*  GPIO_42      PH10        PF42
*  GPIO_43      PH11        PF43
*  GPIO_44      PH12        PF44
*  GPIO_45      PH13        PF45
*  GPIO_46      PH14        PF46
*  GPIO_47      PH15        PF47
*/

#include <linux/module.h>
#include <linux/err.h>
#include <asm/blackfin.h>
#include <asm/gpio.h>
#include <linux/irq.h>

#ifdef BF533_FAMILY
static struct gpio_port_t *gpio_bankb[gpio_bank(MAX_BLACKFIN_GPIOS)] = {
	(struct gpio_port_t *) FIO_FLAG_D,
};
#endif

#ifdef BF537_FAMILY
static struct gpio_port_t *gpio_bankb[gpio_bank(MAX_BLACKFIN_GPIOS)] = {
	(struct gpio_port_t *) PORTFIO,
	(struct gpio_port_t *) PORTGIO,
	(struct gpio_port_t *) PORTHIO,
};

static unsigned short *port_fer[gpio_bank(MAX_BLACKFIN_GPIOS)] = {
	(unsigned short *) PORTF_FER,
	(unsigned short *) PORTG_FER,
	(unsigned short *) PORTH_FER,
};

#endif

#ifdef BF561_FAMILY
static struct gpio_port_t *gpio_bankb[gpio_bank(MAX_BLACKFIN_GPIOS)] = {
	(struct gpio_port_t *) FIO0_FLAG_D,
	(struct gpio_port_t *) FIO1_FLAG_D,
	(struct gpio_port_t *) FIO2_FLAG_D,
};
#endif

static unsigned short reserved_map[gpio_bank(MAX_BLACKFIN_GPIOS)];

#ifdef CONFIG_PM
static unsigned short wakeup_map[gpio_bank(MAX_BLACKFIN_GPIOS)];
static unsigned char wakeup_flags_map[MAX_BLACKFIN_GPIOS];
static struct gpio_port_s gpio_bank_saved[gpio_bank(MAX_BLACKFIN_GPIOS)];

#ifdef BF533_FAMILY
static unsigned int sic_iwr_irqs[gpio_bank(MAX_BLACKFIN_GPIOS)] = {IRQ_PROG_INTB};
#endif

#ifdef BF537_FAMILY
static unsigned int sic_iwr_irqs[gpio_bank(MAX_BLACKFIN_GPIOS)] = {IRQ_PROG_INTB, IRQ_PORTG_INTB, IRQ_MAC_TX};
#endif

#ifdef BF561_FAMILY
static unsigned int sic_iwr_irqs[gpio_bank(MAX_BLACKFIN_GPIOS)] = {IRQ_PROG0_INTB, IRQ_PROG1_INTB, IRQ_PROG2_INTB};
#endif

#endif /* CONFIG_PM */

inline int check_gpio(unsigned short gpio)
{
	if (gpio >= MAX_BLACKFIN_GPIOS)
		return -EINVAL;
	return 0;
}

#ifdef BF537_FAMILY
static void port_setup(unsigned short gpio, unsigned short usage)
{
	if (usage == GPIO_USAGE) {
		if (*port_fer[gpio_bank(gpio)] & gpio_bit(gpio))
			printk(KERN_WARNING "bfin-gpio: Possible Conflict with Peripheral "
			       "usage and GPIO %d detected!\n", gpio);
		*port_fer[gpio_bank(gpio)] &= ~gpio_bit(gpio);
	} else
		*port_fer[gpio_bank(gpio)] |= gpio_bit(gpio);
	SSYNC();
}
#else
# define port_setup(...)  do { } while (0)
#endif


static void default_gpio(unsigned short gpio)
{
	unsigned short bank,bitmask;

	bank = gpio_bank(gpio);
	bitmask = gpio_bit(gpio);

	gpio_bankb[bank]->maska_clear = bitmask;
	gpio_bankb[bank]->maskb_clear = bitmask;
	SSYNC();
	gpio_bankb[bank]->inen &= ~bitmask;
	gpio_bankb[bank]->dir &= ~bitmask;
	gpio_bankb[bank]->polar &= ~bitmask;
	gpio_bankb[bank]->both &= ~bitmask;
	gpio_bankb[bank]->edge &= ~bitmask;
}

static int __init bfin_gpio_init(void)
{
	int i;

	printk(KERN_INFO "Blackfin GPIO Controller\n");

	for (i = 0; i < MAX_BLACKFIN_GPIOS; i+=GPIO_BANKSIZE)
		reserved_map[gpio_bank(i)] = 0;

#if defined(BF537_FAMILY) && (defined(CONFIG_BFIN_MAC) || defined(CONFIG_BFIN_MAC_MODULE))
# if defined(CONFIG_BFIN_MAC_RMII)
	reserved_map[gpio_bank(PORT_H)] = 0xC373;
# else
	reserved_map[gpio_bank(PORT_H)] = 0xFFFF;
# endif
#endif

	return 0;
}

arch_initcall(bfin_gpio_init);


/***********************************************************
*
* FUNCTIONS: Blackfin General Purpose Ports Access Functions
*
* INPUTS/OUTPUTS:
* gpio - GPIO Number between 0 and MAX_BLACKFIN_GPIOS
*
*
* DESCRIPTION: These functions abstract direct register access
*              to Blackfin processor General Purpose
*              Ports Regsiters
*
* CAUTION: These functions do not belong to the GPIO Driver API
*************************************************************
* MODIFICATION HISTORY :
**************************************************************/

/* Set a specific bit */

#define SET_GPIO(name) \
void set_gpio_ ## name(unsigned short gpio, unsigned short arg) \
{ \
	unsigned long flags; \
	BUG_ON(!(reserved_map[gpio_bank(gpio)] & gpio_bit(gpio))); \
	local_irq_save(flags); \
	if (arg) \
		gpio_bankb[gpio_bank(gpio)]->name |= gpio_bit(gpio); \
	else \
		gpio_bankb[gpio_bank(gpio)]->name &= ~gpio_bit(gpio); \
	local_irq_restore(flags); \
} \
EXPORT_SYMBOL(set_gpio_ ## name);

SET_GPIO(dir)
SET_GPIO(inen)
SET_GPIO(polar)
SET_GPIO(edge)
SET_GPIO(both)


#define SET_GPIO_SC(name) \
void set_gpio_ ## name(unsigned short gpio, unsigned short arg) \
{ \
	BUG_ON(!(reserved_map[gpio_bank(gpio)] & gpio_bit(gpio))); \
	if (arg) \
		gpio_bankb[gpio_bank(gpio)]->name ## _set = gpio_bit(gpio); \
	else \
		gpio_bankb[gpio_bank(gpio)]->name ## _clear = gpio_bit(gpio); \
} \
EXPORT_SYMBOL(set_gpio_ ## name);

SET_GPIO_SC(maska)
SET_GPIO_SC(maskb)

#if defined(ANOMALY_05000311)
void set_gpio_data(unsigned short gpio, unsigned short arg)
{
	unsigned long flags;
	BUG_ON(!(reserved_map[gpio_bank(gpio)] & gpio_bit(gpio)));
	local_irq_save(flags);
	if (arg)
		gpio_bankb[gpio_bank(gpio)]->data_set = gpio_bit(gpio);
	else
		gpio_bankb[gpio_bank(gpio)]->data_clear = gpio_bit(gpio);
	bfin_read_CHIPID();
	local_irq_restore(flags);
}
EXPORT_SYMBOL(set_gpio_data);
#else
SET_GPIO_SC(data)
#endif


#if defined(ANOMALY_05000311)
void set_gpio_toggle(unsigned short gpio)
{
	unsigned long flags;
	BUG_ON(!(reserved_map[gpio_bank(gpio)] & gpio_bit(gpio)));
	local_irq_save(flags);
	gpio_bankb[gpio_bank(gpio)]->toggle = gpio_bit(gpio);
	bfin_read_CHIPID();
	local_irq_restore(flags);
}
#else
void set_gpio_toggle(unsigned short gpio)
{
	BUG_ON(!(reserved_map[gpio_bank(gpio)] & gpio_bit(gpio)));
	gpio_bankb[gpio_bank(gpio)]->toggle = gpio_bit(gpio);
}
#endif
EXPORT_SYMBOL(set_gpio_toggle);


/*Set current PORT date (16-bit word)*/

#define SET_GPIO_P(name) \
void set_gpiop_ ## name(unsigned short gpio, unsigned short arg) \
{ \
	gpio_bankb[gpio_bank(gpio)]->name = arg; \
} \
EXPORT_SYMBOL(set_gpiop_ ## name);

SET_GPIO_P(dir)
SET_GPIO_P(inen)
SET_GPIO_P(polar)
SET_GPIO_P(edge)
SET_GPIO_P(both)
SET_GPIO_P(maska)
SET_GPIO_P(maskb)


#if defined(ANOMALY_05000311)
void set_gpiop_data(unsigned short gpio, unsigned short arg)
{
	unsigned long flags;
	local_irq_save(flags);
	gpio_bankb[gpio_bank(gpio)]->data = arg;
	bfin_read_CHIPID();
	local_irq_restore(flags);
}
EXPORT_SYMBOL(set_gpiop_data);
#else
SET_GPIO_P(data)
#endif



/* Get a specific bit */

#define GET_GPIO(name) \
unsigned short get_gpio_ ## name(unsigned short gpio) \
{ \
	return (0x01 & (gpio_bankb[gpio_bank(gpio)]->name >> gpio_sub_n(gpio))); \
} \
EXPORT_SYMBOL(get_gpio_ ## name);

GET_GPIO(dir)
GET_GPIO(inen)
GET_GPIO(polar)
GET_GPIO(edge)
GET_GPIO(both)
GET_GPIO(maska)
GET_GPIO(maskb)


#if defined(ANOMALY_05000311)
unsigned short get_gpio_data(unsigned short gpio)
{
	unsigned long flags;
	unsigned short ret;
	BUG_ON(!(reserved_map[gpio_bank(gpio)] & gpio_bit(gpio)));
	local_irq_save(flags);
	ret = 0x01 & (gpio_bankb[gpio_bank(gpio)]->data >> gpio_sub_n(gpio));
	bfin_read_CHIPID();
	local_irq_restore(flags);
	return ret;
}
EXPORT_SYMBOL(get_gpio_data);
#else
GET_GPIO(data)
#endif

/*Get current PORT date (16-bit word)*/

#define GET_GPIO_P(name) \
unsigned short get_gpiop_ ## name(unsigned short gpio) \
{ \
	return (gpio_bankb[gpio_bank(gpio)]->name);\
} \
EXPORT_SYMBOL(get_gpiop_ ## name);

GET_GPIO_P(dir)
GET_GPIO_P(inen)
GET_GPIO_P(polar)
GET_GPIO_P(edge)
GET_GPIO_P(both)
GET_GPIO_P(maska)
GET_GPIO_P(maskb)

#if defined(ANOMALY_05000311)
unsigned short get_gpiop_data(unsigned short gpio)
{
	unsigned long flags;
	unsigned short ret;
	local_irq_save(flags);
	ret = gpio_bankb[gpio_bank(gpio)]->data;
	bfin_read_CHIPID();
	local_irq_restore(flags);
	return ret;
}
EXPORT_SYMBOL(get_gpiop_data);
#else
GET_GPIO_P(data)
#endif

#ifdef CONFIG_PM
/***********************************************************
*
* FUNCTIONS: Blackfin PM Setup API
*
* INPUTS/OUTPUTS:
* gpio - GPIO Number between 0 and MAX_BLACKFIN_GPIOS
* type -
*	PM_WAKE_RISING
*	PM_WAKE_FALLING
*	PM_WAKE_HIGH
*	PM_WAKE_LOW
*	PM_WAKE_BOTH_EDGES
*
* DESCRIPTION: Blackfin PM Driver API
*
* CAUTION:
*************************************************************
* MODIFICATION HISTORY :
**************************************************************/
int gpio_pm_wakeup_request(unsigned short gpio, unsigned char type)
{
	unsigned long flags;

	if ((check_gpio(gpio) < 0) || !type)
		return -EINVAL;

	local_irq_save(flags);

	wakeup_map[gpio_bank(gpio)] |= gpio_bit(gpio);
	wakeup_flags_map[gpio] = type;
	local_irq_restore(flags);

	return 0;
}
EXPORT_SYMBOL(gpio_pm_wakeup_request);

void gpio_pm_wakeup_free(unsigned short gpio)
{
	unsigned long flags;

	if (check_gpio(gpio) < 0)
		return;

	local_irq_save(flags);

	wakeup_map[gpio_bank(gpio)] &= ~gpio_bit(gpio);

	local_irq_restore(flags);
}
EXPORT_SYMBOL(gpio_pm_wakeup_free);

static int bfin_gpio_wakeup_type(unsigned short gpio, unsigned char type)
{
	port_setup(gpio, GPIO_USAGE);
	set_gpio_dir(gpio, 0);
	set_gpio_inen(gpio, 1);

	if (type & (PM_WAKE_RISING | PM_WAKE_FALLING))
		set_gpio_edge(gpio, 1);
	 else
		set_gpio_edge(gpio, 0);

	if ((type & (PM_WAKE_BOTH_EDGES)) == (PM_WAKE_BOTH_EDGES))
		set_gpio_both(gpio, 1);
	else
		set_gpio_both(gpio, 0);

	if ((type & (PM_WAKE_FALLING | PM_WAKE_LOW)))
		set_gpio_polar(gpio, 1);
	else
		set_gpio_polar(gpio, 0);

	SSYNC();

	return 0;
}

u32 gpio_pm_setup(void)
{
	u32 sic_iwr = 0;
	u16 bank, mask, i, gpio;

	for (i = 0; i < MAX_BLACKFIN_GPIOS; i+=GPIO_BANKSIZE) {
		mask = wakeup_map[gpio_bank(i)];
		bank = gpio_bank(i);

		gpio_bank_saved[bank].maskb = gpio_bankb[bank]->maskb;
		gpio_bankb[bank]->maskb = 0;

		if (mask) {
#ifdef BF537_FAMILY
			gpio_bank_saved[bank].fer   = *port_fer[bank];
#endif
			gpio_bank_saved[bank].inen  = gpio_bankb[bank]->inen;
			gpio_bank_saved[bank].polar = gpio_bankb[bank]->polar;
			gpio_bank_saved[bank].dir   = gpio_bankb[bank]->dir;
			gpio_bank_saved[bank].edge  = gpio_bankb[bank]->edge;
			gpio_bank_saved[bank].both  = gpio_bankb[bank]->both;

			gpio = i;

			while (mask) {
				if (mask & 1) {
					bfin_gpio_wakeup_type(gpio, wakeup_flags_map[gpio]);
					set_gpio_data(gpio, 0); /*Clear*/
				}
				gpio++;
				mask >>= 1;
			}

			sic_iwr |= 1 << (sic_iwr_irqs[bank] - (IRQ_CORETMR + 1));
			gpio_bankb[bank]->maskb_set = wakeup_map[gpio_bank(i)];
		}
	}

	if (sic_iwr)
		return sic_iwr;
	else
		return IWR_ENABLE_ALL;
}


void gpio_pm_restore(void)
{
	u16 bank, mask, i;

	for (i = 0; i < MAX_BLACKFIN_GPIOS; i+=GPIO_BANKSIZE) {
		mask = wakeup_map[gpio_bank(i)];
		bank = gpio_bank(i);

		if (mask) {
#ifdef BF537_FAMILY
			*port_fer[bank]   	= gpio_bank_saved[bank].fer;
#endif
			gpio_bankb[bank]->inen  = gpio_bank_saved[bank].inen;
			gpio_bankb[bank]->dir   = gpio_bank_saved[bank].dir;
			gpio_bankb[bank]->polar = gpio_bank_saved[bank].polar;
			gpio_bankb[bank]->edge  = gpio_bank_saved[bank].edge;
			gpio_bankb[bank]->both  = gpio_bank_saved[bank].both;
		}

		gpio_bankb[bank]->maskb = gpio_bank_saved[bank].maskb;
	}
}

#endif

/***********************************************************
*
* FUNCTIONS: Blackfin GPIO Driver
*
* INPUTS/OUTPUTS:
* gpio - GPIO Number between 0 and MAX_BLACKFIN_GPIOS
*
*
* DESCRIPTION: Blackfin GPIO Driver API
*
* CAUTION:
*************************************************************
* MODIFICATION HISTORY :
**************************************************************/

int gpio_request(unsigned short gpio, const char *label)
{
	unsigned long flags;

	if (check_gpio(gpio) < 0)
		return -EINVAL;

	local_irq_save(flags);

	if (unlikely(reserved_map[gpio_bank(gpio)] & gpio_bit(gpio))) {
		printk(KERN_ERR "bfin-gpio: GPIO %d is already reserved!\n", gpio);
		dump_stack();
		local_irq_restore(flags);
		return -EBUSY;
	}
	reserved_map[gpio_bank(gpio)] |= gpio_bit(gpio);

	local_irq_restore(flags);

	port_setup(gpio, GPIO_USAGE);

	return 0;
}
EXPORT_SYMBOL(gpio_request);


void gpio_free(unsigned short gpio)
{
	unsigned long flags;

	if (check_gpio(gpio) < 0)
		return;

	local_irq_save(flags);

	if (unlikely(!(reserved_map[gpio_bank(gpio)] & gpio_bit(gpio)))) {
		printk(KERN_ERR "bfin-gpio: GPIO %d wasn't reserved!\n", gpio);
		dump_stack();
		local_irq_restore(flags);
		return;
	}

	default_gpio(gpio);

	reserved_map[gpio_bank(gpio)] &= ~gpio_bit(gpio);

	local_irq_restore(flags);
}
EXPORT_SYMBOL(gpio_free);


void gpio_direction_input(unsigned short gpio)
{
	unsigned long flags;

	BUG_ON(!(reserved_map[gpio_bank(gpio)] & gpio_bit(gpio)));

	local_irq_save(flags);
	gpio_bankb[gpio_bank(gpio)]->dir &= ~gpio_bit(gpio);
	gpio_bankb[gpio_bank(gpio)]->inen |= gpio_bit(gpio);
	local_irq_restore(flags);
}
EXPORT_SYMBOL(gpio_direction_input);

void gpio_direction_output(unsigned short gpio)
{
	unsigned long flags;

	BUG_ON(!(reserved_map[gpio_bank(gpio)] & gpio_bit(gpio)));

	local_irq_save(flags);
	gpio_bankb[gpio_bank(gpio)]->inen &= ~gpio_bit(gpio);
	gpio_bankb[gpio_bank(gpio)]->dir |= gpio_bit(gpio);
	local_irq_restore(flags);
}
EXPORT_SYMBOL(gpio_direction_output);