1 /*
2 * Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
3 * JZ4740 platform GPIO support
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; either version 2 of the License, or (at your
8 * option) any later version.
9 *
10 * You should have received a copy of the GNU General Public License along
11 * with this program; if not, write to the Free Software Foundation, Inc.,
12 * 675 Mass Ave, Cambridge, MA 02139, USA.
13 *
14 */
15
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/init.h>
19
20 #include <linux/io.h>
21 #include <linux/gpio.h>
22 #include <linux/delay.h>
23 #include <linux/interrupt.h>
24 #include <linux/bitops.h>
25
26 #include <linux/debugfs.h>
27 #include <linux/seq_file.h>
28
29 #include <asm/mach-jz4740/base.h>
30
31 #include "irq.h"
32
33 #define JZ4740_GPIO_BASE_A (32*0)
34 #define JZ4740_GPIO_BASE_B (32*1)
35 #define JZ4740_GPIO_BASE_C (32*2)
36 #define JZ4740_GPIO_BASE_D (32*3)
37
38 #define JZ4740_GPIO_NUM_A 32
39 #define JZ4740_GPIO_NUM_B 32
40 #define JZ4740_GPIO_NUM_C 31
41 #define JZ4740_GPIO_NUM_D 32
42
43 #define JZ4740_IRQ_GPIO_BASE_A (JZ4740_IRQ_GPIO(0) + JZ4740_GPIO_BASE_A)
44 #define JZ4740_IRQ_GPIO_BASE_B (JZ4740_IRQ_GPIO(0) + JZ4740_GPIO_BASE_B)
45 #define JZ4740_IRQ_GPIO_BASE_C (JZ4740_IRQ_GPIO(0) + JZ4740_GPIO_BASE_C)
46 #define JZ4740_IRQ_GPIO_BASE_D (JZ4740_IRQ_GPIO(0) + JZ4740_GPIO_BASE_D)
47
48 #define JZ_REG_GPIO_PIN 0x00
49 #define JZ_REG_GPIO_DATA 0x10
50 #define JZ_REG_GPIO_DATA_SET 0x14
51 #define JZ_REG_GPIO_DATA_CLEAR 0x18
52 #define JZ_REG_GPIO_MASK 0x20
53 #define JZ_REG_GPIO_MASK_SET 0x24
54 #define JZ_REG_GPIO_MASK_CLEAR 0x28
55 #define JZ_REG_GPIO_PULL 0x30
56 #define JZ_REG_GPIO_PULL_SET 0x34
57 #define JZ_REG_GPIO_PULL_CLEAR 0x38
58 #define JZ_REG_GPIO_FUNC 0x40
59 #define JZ_REG_GPIO_FUNC_SET 0x44
60 #define JZ_REG_GPIO_FUNC_CLEAR 0x48
61 #define JZ_REG_GPIO_SELECT 0x50
62 #define JZ_REG_GPIO_SELECT_SET 0x54
63 #define JZ_REG_GPIO_SELECT_CLEAR 0x58
64 #define JZ_REG_GPIO_DIRECTION 0x60
65 #define JZ_REG_GPIO_DIRECTION_SET 0x64
66 #define JZ_REG_GPIO_DIRECTION_CLEAR 0x68
67 #define JZ_REG_GPIO_TRIGGER 0x70
68 #define JZ_REG_GPIO_TRIGGER_SET 0x74
69 #define JZ_REG_GPIO_TRIGGER_CLEAR 0x78
70 #define JZ_REG_GPIO_FLAG 0x80
71 #define JZ_REG_GPIO_FLAG_CLEAR 0x14
72
73 #define GPIO_TO_BIT(gpio) BIT(gpio & 0x1f)
74 #define GPIO_TO_REG(gpio, reg) (gpio_to_jz_gpio_chip(gpio)->base + (reg))
75 #define CHIP_TO_REG(chip, reg) (gpio_chip_to_jz_gpio_chip(chip)->base + (reg))
76
77 struct jz_gpio_chip {
78 unsigned int irq;
79 unsigned int irq_base;
80 uint32_t edge_trigger_both;
81
82 void __iomem *base;
83
84 struct gpio_chip gpio_chip;
85 };
86
87 static struct jz_gpio_chip jz4740_gpio_chips[];
88
gpio_to_jz_gpio_chip(unsigned int gpio)89 static inline struct jz_gpio_chip *gpio_to_jz_gpio_chip(unsigned int gpio)
90 {
91 return &jz4740_gpio_chips[gpio >> 5];
92 }
93
gpio_chip_to_jz_gpio_chip(struct gpio_chip * gpio_chip)94 static inline struct jz_gpio_chip *gpio_chip_to_jz_gpio_chip(struct gpio_chip *gpio_chip)
95 {
96 return container_of(gpio_chip, struct jz_gpio_chip, gpio_chip);
97 }
98
irq_to_jz_gpio_chip(struct irq_data * data)99 static inline struct jz_gpio_chip *irq_to_jz_gpio_chip(struct irq_data *data)
100 {
101 struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
102 return gc->private;
103 }
104
jz_gpio_write_bit(unsigned int gpio,unsigned int reg)105 static inline void jz_gpio_write_bit(unsigned int gpio, unsigned int reg)
106 {
107 writel(GPIO_TO_BIT(gpio), GPIO_TO_REG(gpio, reg));
108 }
109
jz_gpio_set_function(int gpio,enum jz_gpio_function function)110 int jz_gpio_set_function(int gpio, enum jz_gpio_function function)
111 {
112 if (function == JZ_GPIO_FUNC_NONE) {
113 jz_gpio_write_bit(gpio, JZ_REG_GPIO_FUNC_CLEAR);
114 jz_gpio_write_bit(gpio, JZ_REG_GPIO_SELECT_CLEAR);
115 jz_gpio_write_bit(gpio, JZ_REG_GPIO_TRIGGER_CLEAR);
116 } else {
117 jz_gpio_write_bit(gpio, JZ_REG_GPIO_FUNC_SET);
118 jz_gpio_write_bit(gpio, JZ_REG_GPIO_TRIGGER_CLEAR);
119 switch (function) {
120 case JZ_GPIO_FUNC1:
121 jz_gpio_write_bit(gpio, JZ_REG_GPIO_SELECT_CLEAR);
122 break;
123 case JZ_GPIO_FUNC3:
124 jz_gpio_write_bit(gpio, JZ_REG_GPIO_TRIGGER_SET);
125 case JZ_GPIO_FUNC2: /* Falltrough */
126 jz_gpio_write_bit(gpio, JZ_REG_GPIO_SELECT_SET);
127 break;
128 default:
129 BUG();
130 break;
131 }
132 }
133
134 return 0;
135 }
136 EXPORT_SYMBOL_GPL(jz_gpio_set_function);
137
jz_gpio_bulk_request(const struct jz_gpio_bulk_request * request,size_t num)138 int jz_gpio_bulk_request(const struct jz_gpio_bulk_request *request, size_t num)
139 {
140 size_t i;
141 int ret;
142
143 for (i = 0; i < num; ++i, ++request) {
144 ret = gpio_request(request->gpio, request->name);
145 if (ret)
146 goto err;
147 jz_gpio_set_function(request->gpio, request->function);
148 }
149
150 return 0;
151
152 err:
153 for (--request; i > 0; --i, --request) {
154 gpio_free(request->gpio);
155 jz_gpio_set_function(request->gpio, JZ_GPIO_FUNC_NONE);
156 }
157
158 return ret;
159 }
160 EXPORT_SYMBOL_GPL(jz_gpio_bulk_request);
161
jz_gpio_bulk_free(const struct jz_gpio_bulk_request * request,size_t num)162 void jz_gpio_bulk_free(const struct jz_gpio_bulk_request *request, size_t num)
163 {
164 size_t i;
165
166 for (i = 0; i < num; ++i, ++request) {
167 gpio_free(request->gpio);
168 jz_gpio_set_function(request->gpio, JZ_GPIO_FUNC_NONE);
169 }
170
171 }
172 EXPORT_SYMBOL_GPL(jz_gpio_bulk_free);
173
jz_gpio_bulk_suspend(const struct jz_gpio_bulk_request * request,size_t num)174 void jz_gpio_bulk_suspend(const struct jz_gpio_bulk_request *request, size_t num)
175 {
176 size_t i;
177
178 for (i = 0; i < num; ++i, ++request) {
179 jz_gpio_set_function(request->gpio, JZ_GPIO_FUNC_NONE);
180 jz_gpio_write_bit(request->gpio, JZ_REG_GPIO_DIRECTION_CLEAR);
181 jz_gpio_write_bit(request->gpio, JZ_REG_GPIO_PULL_SET);
182 }
183 }
184 EXPORT_SYMBOL_GPL(jz_gpio_bulk_suspend);
185
jz_gpio_bulk_resume(const struct jz_gpio_bulk_request * request,size_t num)186 void jz_gpio_bulk_resume(const struct jz_gpio_bulk_request *request, size_t num)
187 {
188 size_t i;
189
190 for (i = 0; i < num; ++i, ++request)
191 jz_gpio_set_function(request->gpio, request->function);
192 }
193 EXPORT_SYMBOL_GPL(jz_gpio_bulk_resume);
194
jz_gpio_enable_pullup(unsigned gpio)195 void jz_gpio_enable_pullup(unsigned gpio)
196 {
197 jz_gpio_write_bit(gpio, JZ_REG_GPIO_PULL_CLEAR);
198 }
199 EXPORT_SYMBOL_GPL(jz_gpio_enable_pullup);
200
jz_gpio_disable_pullup(unsigned gpio)201 void jz_gpio_disable_pullup(unsigned gpio)
202 {
203 jz_gpio_write_bit(gpio, JZ_REG_GPIO_PULL_SET);
204 }
205 EXPORT_SYMBOL_GPL(jz_gpio_disable_pullup);
206
jz_gpio_get_value(struct gpio_chip * chip,unsigned gpio)207 static int jz_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
208 {
209 return !!(readl(CHIP_TO_REG(chip, JZ_REG_GPIO_PIN)) & BIT(gpio));
210 }
211
jz_gpio_set_value(struct gpio_chip * chip,unsigned gpio,int value)212 static void jz_gpio_set_value(struct gpio_chip *chip, unsigned gpio, int value)
213 {
214 uint32_t __iomem *reg = CHIP_TO_REG(chip, JZ_REG_GPIO_DATA_SET);
215 reg += !value;
216 writel(BIT(gpio), reg);
217 }
218
jz_gpio_direction_output(struct gpio_chip * chip,unsigned gpio,int value)219 static int jz_gpio_direction_output(struct gpio_chip *chip, unsigned gpio,
220 int value)
221 {
222 writel(BIT(gpio), CHIP_TO_REG(chip, JZ_REG_GPIO_DIRECTION_SET));
223 jz_gpio_set_value(chip, gpio, value);
224
225 return 0;
226 }
227
jz_gpio_direction_input(struct gpio_chip * chip,unsigned gpio)228 static int jz_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
229 {
230 writel(BIT(gpio), CHIP_TO_REG(chip, JZ_REG_GPIO_DIRECTION_CLEAR));
231
232 return 0;
233 }
234
jz_gpio_port_direction_input(int port,uint32_t mask)235 int jz_gpio_port_direction_input(int port, uint32_t mask)
236 {
237 writel(mask, GPIO_TO_REG(port, JZ_REG_GPIO_DIRECTION_CLEAR));
238
239 return 0;
240 }
241 EXPORT_SYMBOL(jz_gpio_port_direction_input);
242
jz_gpio_port_direction_output(int port,uint32_t mask)243 int jz_gpio_port_direction_output(int port, uint32_t mask)
244 {
245 writel(mask, GPIO_TO_REG(port, JZ_REG_GPIO_DIRECTION_SET));
246
247 return 0;
248 }
249 EXPORT_SYMBOL(jz_gpio_port_direction_output);
250
jz_gpio_port_set_value(int port,uint32_t value,uint32_t mask)251 void jz_gpio_port_set_value(int port, uint32_t value, uint32_t mask)
252 {
253 writel(~value & mask, GPIO_TO_REG(port, JZ_REG_GPIO_DATA_CLEAR));
254 writel(value & mask, GPIO_TO_REG(port, JZ_REG_GPIO_DATA_SET));
255 }
256 EXPORT_SYMBOL(jz_gpio_port_set_value);
257
jz_gpio_port_get_value(int port,uint32_t mask)258 uint32_t jz_gpio_port_get_value(int port, uint32_t mask)
259 {
260 uint32_t value = readl(GPIO_TO_REG(port, JZ_REG_GPIO_PIN));
261
262 return value & mask;
263 }
264 EXPORT_SYMBOL(jz_gpio_port_get_value);
265
gpio_to_irq(unsigned gpio)266 int gpio_to_irq(unsigned gpio)
267 {
268 return JZ4740_IRQ_GPIO(0) + gpio;
269 }
270 EXPORT_SYMBOL_GPL(gpio_to_irq);
271
irq_to_gpio(unsigned irq)272 int irq_to_gpio(unsigned irq)
273 {
274 return irq - JZ4740_IRQ_GPIO(0);
275 }
276 EXPORT_SYMBOL_GPL(irq_to_gpio);
277
278 #define IRQ_TO_BIT(irq) BIT(irq_to_gpio(irq) & 0x1f)
279
jz_gpio_check_trigger_both(struct jz_gpio_chip * chip,unsigned int irq)280 static void jz_gpio_check_trigger_both(struct jz_gpio_chip *chip, unsigned int irq)
281 {
282 uint32_t value;
283 void __iomem *reg;
284 uint32_t mask = IRQ_TO_BIT(irq);
285
286 if (!(chip->edge_trigger_both & mask))
287 return;
288
289 reg = chip->base;
290
291 value = readl(chip->base + JZ_REG_GPIO_PIN);
292 if (value & mask)
293 reg += JZ_REG_GPIO_DIRECTION_CLEAR;
294 else
295 reg += JZ_REG_GPIO_DIRECTION_SET;
296
297 writel(mask, reg);
298 }
299
jz_gpio_irq_demux_handler(unsigned int irq,struct irq_desc * desc)300 static void jz_gpio_irq_demux_handler(unsigned int irq, struct irq_desc *desc)
301 {
302 uint32_t flag;
303 unsigned int gpio_irq;
304 struct jz_gpio_chip *chip = irq_desc_get_handler_data(desc);
305
306 flag = readl(chip->base + JZ_REG_GPIO_FLAG);
307 if (!flag)
308 return;
309
310 gpio_irq = chip->irq_base + __fls(flag);
311
312 jz_gpio_check_trigger_both(chip, gpio_irq);
313
314 generic_handle_irq(gpio_irq);
315 };
316
jz_gpio_set_irq_bit(struct irq_data * data,unsigned int reg)317 static inline void jz_gpio_set_irq_bit(struct irq_data *data, unsigned int reg)
318 {
319 struct jz_gpio_chip *chip = irq_to_jz_gpio_chip(data);
320 writel(IRQ_TO_BIT(data->irq), chip->base + reg);
321 }
322
jz_gpio_irq_unmask(struct irq_data * data)323 static void jz_gpio_irq_unmask(struct irq_data *data)
324 {
325 struct jz_gpio_chip *chip = irq_to_jz_gpio_chip(data);
326
327 jz_gpio_check_trigger_both(chip, data->irq);
328 irq_gc_unmask_enable_reg(data);
329 };
330
331 /* TODO: Check if function is gpio */
jz_gpio_irq_startup(struct irq_data * data)332 static unsigned int jz_gpio_irq_startup(struct irq_data *data)
333 {
334 jz_gpio_set_irq_bit(data, JZ_REG_GPIO_SELECT_SET);
335 jz_gpio_irq_unmask(data);
336 return 0;
337 }
338
jz_gpio_irq_shutdown(struct irq_data * data)339 static void jz_gpio_irq_shutdown(struct irq_data *data)
340 {
341 irq_gc_mask_disable_reg(data);
342
343 /* Set direction to input */
344 jz_gpio_set_irq_bit(data, JZ_REG_GPIO_DIRECTION_CLEAR);
345 jz_gpio_set_irq_bit(data, JZ_REG_GPIO_SELECT_CLEAR);
346 }
347
jz_gpio_irq_set_type(struct irq_data * data,unsigned int flow_type)348 static int jz_gpio_irq_set_type(struct irq_data *data, unsigned int flow_type)
349 {
350 struct jz_gpio_chip *chip = irq_to_jz_gpio_chip(data);
351 unsigned int irq = data->irq;
352
353 if (flow_type == IRQ_TYPE_EDGE_BOTH) {
354 uint32_t value = readl(chip->base + JZ_REG_GPIO_PIN);
355 if (value & IRQ_TO_BIT(irq))
356 flow_type = IRQ_TYPE_EDGE_FALLING;
357 else
358 flow_type = IRQ_TYPE_EDGE_RISING;
359 chip->edge_trigger_both |= IRQ_TO_BIT(irq);
360 } else {
361 chip->edge_trigger_both &= ~IRQ_TO_BIT(irq);
362 }
363
364 switch (flow_type) {
365 case IRQ_TYPE_EDGE_RISING:
366 jz_gpio_set_irq_bit(data, JZ_REG_GPIO_DIRECTION_SET);
367 jz_gpio_set_irq_bit(data, JZ_REG_GPIO_TRIGGER_SET);
368 break;
369 case IRQ_TYPE_EDGE_FALLING:
370 jz_gpio_set_irq_bit(data, JZ_REG_GPIO_DIRECTION_CLEAR);
371 jz_gpio_set_irq_bit(data, JZ_REG_GPIO_TRIGGER_SET);
372 break;
373 case IRQ_TYPE_LEVEL_HIGH:
374 jz_gpio_set_irq_bit(data, JZ_REG_GPIO_DIRECTION_SET);
375 jz_gpio_set_irq_bit(data, JZ_REG_GPIO_TRIGGER_CLEAR);
376 break;
377 case IRQ_TYPE_LEVEL_LOW:
378 jz_gpio_set_irq_bit(data, JZ_REG_GPIO_DIRECTION_CLEAR);
379 jz_gpio_set_irq_bit(data, JZ_REG_GPIO_TRIGGER_CLEAR);
380 break;
381 default:
382 return -EINVAL;
383 }
384
385 return 0;
386 }
387
jz_gpio_irq_set_wake(struct irq_data * data,unsigned int on)388 static int jz_gpio_irq_set_wake(struct irq_data *data, unsigned int on)
389 {
390 struct jz_gpio_chip *chip = irq_to_jz_gpio_chip(data);
391
392 irq_gc_set_wake(data, on);
393 irq_set_irq_wake(chip->irq, on);
394
395 return 0;
396 }
397
398 #define JZ4740_GPIO_CHIP(_bank) { \
399 .irq_base = JZ4740_IRQ_GPIO_BASE_ ## _bank, \
400 .gpio_chip = { \
401 .label = "Bank " # _bank, \
402 .owner = THIS_MODULE, \
403 .set = jz_gpio_set_value, \
404 .get = jz_gpio_get_value, \
405 .direction_output = jz_gpio_direction_output, \
406 .direction_input = jz_gpio_direction_input, \
407 .base = JZ4740_GPIO_BASE_ ## _bank, \
408 .ngpio = JZ4740_GPIO_NUM_ ## _bank, \
409 }, \
410 }
411
412 static struct jz_gpio_chip jz4740_gpio_chips[] = {
413 JZ4740_GPIO_CHIP(A),
414 JZ4740_GPIO_CHIP(B),
415 JZ4740_GPIO_CHIP(C),
416 JZ4740_GPIO_CHIP(D),
417 };
418
jz4740_gpio_chip_init(struct jz_gpio_chip * chip,unsigned int id)419 static void jz4740_gpio_chip_init(struct jz_gpio_chip *chip, unsigned int id)
420 {
421 struct irq_chip_generic *gc;
422 struct irq_chip_type *ct;
423
424 chip->base = ioremap(JZ4740_GPIO_BASE_ADDR + (id * 0x100), 0x100);
425
426 chip->irq = JZ4740_IRQ_INTC_GPIO(id);
427 irq_set_handler_data(chip->irq, chip);
428 irq_set_chained_handler(chip->irq, jz_gpio_irq_demux_handler);
429
430 gc = irq_alloc_generic_chip(chip->gpio_chip.label, 1, chip->irq_base,
431 chip->base, handle_level_irq);
432
433 gc->wake_enabled = IRQ_MSK(chip->gpio_chip.ngpio);
434 gc->private = chip;
435
436 ct = gc->chip_types;
437 ct->regs.enable = JZ_REG_GPIO_MASK_CLEAR;
438 ct->regs.disable = JZ_REG_GPIO_MASK_SET;
439 ct->regs.ack = JZ_REG_GPIO_FLAG_CLEAR;
440
441 ct->chip.name = "GPIO";
442 ct->chip.irq_mask = irq_gc_mask_disable_reg;
443 ct->chip.irq_unmask = jz_gpio_irq_unmask;
444 ct->chip.irq_ack = irq_gc_ack_set_bit;
445 ct->chip.irq_suspend = jz4740_irq_suspend;
446 ct->chip.irq_resume = jz4740_irq_resume;
447 ct->chip.irq_startup = jz_gpio_irq_startup;
448 ct->chip.irq_shutdown = jz_gpio_irq_shutdown;
449 ct->chip.irq_set_type = jz_gpio_irq_set_type;
450 ct->chip.irq_set_wake = jz_gpio_irq_set_wake;
451 ct->chip.flags = IRQCHIP_SET_TYPE_MASKED;
452
453 irq_setup_generic_chip(gc, IRQ_MSK(chip->gpio_chip.ngpio),
454 IRQ_GC_INIT_NESTED_LOCK, 0, IRQ_NOPROBE | IRQ_LEVEL);
455
456 gpiochip_add(&chip->gpio_chip);
457 }
458
jz4740_gpio_init(void)459 static int __init jz4740_gpio_init(void)
460 {
461 unsigned int i;
462
463 for (i = 0; i < ARRAY_SIZE(jz4740_gpio_chips); ++i)
464 jz4740_gpio_chip_init(&jz4740_gpio_chips[i], i);
465
466 printk(KERN_INFO "JZ4740 GPIO initialized\n");
467
468 return 0;
469 }
470 arch_initcall(jz4740_gpio_init);
471
472 #ifdef CONFIG_DEBUG_FS
473
gpio_seq_reg(struct seq_file * s,struct jz_gpio_chip * chip,const char * name,unsigned int reg)474 static inline void gpio_seq_reg(struct seq_file *s, struct jz_gpio_chip *chip,
475 const char *name, unsigned int reg)
476 {
477 seq_printf(s, "\t%s: %08x\n", name, readl(chip->base + reg));
478 }
479
gpio_regs_show(struct seq_file * s,void * unused)480 static int gpio_regs_show(struct seq_file *s, void *unused)
481 {
482 struct jz_gpio_chip *chip = jz4740_gpio_chips;
483 int i;
484
485 for (i = 0; i < ARRAY_SIZE(jz4740_gpio_chips); ++i, ++chip) {
486 seq_printf(s, "==GPIO %d==\n", i);
487 gpio_seq_reg(s, chip, "Pin", JZ_REG_GPIO_PIN);
488 gpio_seq_reg(s, chip, "Data", JZ_REG_GPIO_DATA);
489 gpio_seq_reg(s, chip, "Mask", JZ_REG_GPIO_MASK);
490 gpio_seq_reg(s, chip, "Pull", JZ_REG_GPIO_PULL);
491 gpio_seq_reg(s, chip, "Func", JZ_REG_GPIO_FUNC);
492 gpio_seq_reg(s, chip, "Select", JZ_REG_GPIO_SELECT);
493 gpio_seq_reg(s, chip, "Direction", JZ_REG_GPIO_DIRECTION);
494 gpio_seq_reg(s, chip, "Trigger", JZ_REG_GPIO_TRIGGER);
495 gpio_seq_reg(s, chip, "Flag", JZ_REG_GPIO_FLAG);
496 }
497
498 return 0;
499 }
500
gpio_regs_open(struct inode * inode,struct file * file)501 static int gpio_regs_open(struct inode *inode, struct file *file)
502 {
503 return single_open(file, gpio_regs_show, NULL);
504 }
505
506 static const struct file_operations gpio_regs_operations = {
507 .open = gpio_regs_open,
508 .read = seq_read,
509 .llseek = seq_lseek,
510 .release = single_release,
511 };
512
gpio_debugfs_init(void)513 static int __init gpio_debugfs_init(void)
514 {
515 (void) debugfs_create_file("jz_regs_gpio", S_IFREG | S_IRUGO,
516 NULL, NULL, &gpio_regs_operations);
517 return 0;
518 }
519 subsys_initcall(gpio_debugfs_init);
520
521 #endif
522