1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * GPIO Testing Device Driver
4  *
5  * Copyright (C) 2014  Kamlakant Patel <kamlakant.patel@broadcom.com>
6  * Copyright (C) 2015-2016  Bamvor Jian Zhang <bamv2005@gmail.com>
7  * Copyright (C) 2017 Bartosz Golaszewski <brgl@bgdev.pl>
8  */
9 
10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11 
12 #include <linux/cleanup.h>
13 #include <linux/debugfs.h>
14 #include <linux/device.h>
15 #include <linux/gpio/driver.h>
16 #include <linux/interrupt.h>
17 #include <linux/irq.h>
18 #include <linux/irq_sim.h>
19 #include <linux/irqdomain.h>
20 #include <linux/mod_devicetable.h>
21 #include <linux/module.h>
22 #include <linux/platform_device.h>
23 #include <linux/property.h>
24 #include <linux/seq_file.h>
25 #include <linux/slab.h>
26 #include <linux/string_helpers.h>
27 #include <linux/uaccess.h>
28 
29 #define GPIO_MOCKUP_MAX_GC	10
30 /*
31  * We're storing two values per chip: the GPIO base and the number
32  * of GPIO lines.
33  */
34 #define GPIO_MOCKUP_MAX_RANGES	(GPIO_MOCKUP_MAX_GC * 2)
35 /* Maximum of four properties + the sentinel. */
36 #define GPIO_MOCKUP_MAX_PROP	5
37 
38 /*
39  * struct gpio_pin_status - structure describing a GPIO status
40  * @dir:       Configures direction of gpio as "in" or "out"
41  * @value:     Configures status of the gpio as 0(low) or 1(high)
42  * @pull:      Configures the current pull of the GPIO as 0 (pull-down) or
43  *             1 (pull-up)
44  * @requested: Request status of this GPIO
45  */
46 struct gpio_mockup_line_status {
47 	int dir;
48 	int value;
49 	int pull;
50 	bool requested;
51 };
52 
53 struct gpio_mockup_chip {
54 	struct gpio_chip gc;
55 	struct gpio_mockup_line_status *lines;
56 	struct irq_domain *irq_sim_domain;
57 	struct dentry *dbg_dir;
58 	struct mutex lock;
59 };
60 
61 struct gpio_mockup_dbgfs_private {
62 	struct gpio_mockup_chip *chip;
63 	unsigned int offset;
64 };
65 
66 static int gpio_mockup_ranges[GPIO_MOCKUP_MAX_RANGES];
67 static int gpio_mockup_num_ranges;
68 module_param_array(gpio_mockup_ranges, int, &gpio_mockup_num_ranges, 0400);
69 
70 static bool gpio_mockup_named_lines;
71 module_param_named(gpio_mockup_named_lines,
72 		   gpio_mockup_named_lines, bool, 0400);
73 
74 static struct dentry *gpio_mockup_dbg_dir;
75 
gpio_mockup_range_base(unsigned int index)76 static int gpio_mockup_range_base(unsigned int index)
77 {
78 	return gpio_mockup_ranges[index * 2];
79 }
80 
gpio_mockup_range_ngpio(unsigned int index)81 static int gpio_mockup_range_ngpio(unsigned int index)
82 {
83 	return gpio_mockup_ranges[index * 2 + 1];
84 }
85 
__gpio_mockup_get(struct gpio_mockup_chip * chip,unsigned int offset)86 static int __gpio_mockup_get(struct gpio_mockup_chip *chip,
87 			     unsigned int offset)
88 {
89 	return chip->lines[offset].value;
90 }
91 
gpio_mockup_get(struct gpio_chip * gc,unsigned int offset)92 static int gpio_mockup_get(struct gpio_chip *gc, unsigned int offset)
93 {
94 	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
95 	int val;
96 
97 	scoped_guard(mutex, &chip->lock)
98 		val = __gpio_mockup_get(chip, offset);
99 
100 	return val;
101 }
102 
gpio_mockup_get_multiple(struct gpio_chip * gc,unsigned long * mask,unsigned long * bits)103 static int gpio_mockup_get_multiple(struct gpio_chip *gc,
104 				    unsigned long *mask, unsigned long *bits)
105 {
106 	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
107 	unsigned int bit, val;
108 
109 	scoped_guard(mutex, &chip->lock) {
110 		for_each_set_bit(bit, mask, gc->ngpio) {
111 			val = __gpio_mockup_get(chip, bit);
112 			__assign_bit(bit, bits, val);
113 		}
114 	}
115 
116 	return 0;
117 }
118 
__gpio_mockup_set(struct gpio_mockup_chip * chip,unsigned int offset,int value)119 static void __gpio_mockup_set(struct gpio_mockup_chip *chip,
120 			      unsigned int offset, int value)
121 {
122 	chip->lines[offset].value = !!value;
123 }
124 
gpio_mockup_set(struct gpio_chip * gc,unsigned int offset,int value)125 static void gpio_mockup_set(struct gpio_chip *gc,
126 			   unsigned int offset, int value)
127 {
128 	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
129 
130 	guard(mutex)(&chip->lock);
131 
132 	__gpio_mockup_set(chip, offset, value);
133 }
134 
gpio_mockup_set_multiple(struct gpio_chip * gc,unsigned long * mask,unsigned long * bits)135 static void gpio_mockup_set_multiple(struct gpio_chip *gc,
136 				     unsigned long *mask, unsigned long *bits)
137 {
138 	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
139 	unsigned int bit;
140 
141 	guard(mutex)(&chip->lock);
142 
143 	for_each_set_bit(bit, mask, gc->ngpio)
144 		__gpio_mockup_set(chip, bit, test_bit(bit, bits));
145 }
146 
gpio_mockup_apply_pull(struct gpio_mockup_chip * chip,unsigned int offset,int value)147 static int gpio_mockup_apply_pull(struct gpio_mockup_chip *chip,
148 				  unsigned int offset, int value)
149 {
150 	struct gpio_mockup_line_status *line = &chip->lines[offset];
151 	int curr, irq, irq_type, ret = 0;
152 
153 	guard(mutex)(&chip->lock);
154 
155 	if (line->requested && line->dir == GPIO_LINE_DIRECTION_IN) {
156 		curr = __gpio_mockup_get(chip, offset);
157 		if (curr == value)
158 			goto out;
159 
160 		irq = irq_find_mapping(chip->irq_sim_domain, offset);
161 		if (!irq)
162 			/*
163 			 * This is fine - it just means, nobody is listening
164 			 * for interrupts on this line, otherwise
165 			 * irq_create_mapping() would have been called from
166 			 * the to_irq() callback.
167 			 */
168 			goto set_value;
169 
170 		irq_type = irq_get_trigger_type(irq);
171 
172 		if ((value == 1 && (irq_type & IRQ_TYPE_EDGE_RISING)) ||
173 		    (value == 0 && (irq_type & IRQ_TYPE_EDGE_FALLING))) {
174 			ret = irq_set_irqchip_state(irq, IRQCHIP_STATE_PENDING,
175 						    true);
176 			if (ret)
177 				goto out;
178 		}
179 	}
180 
181 set_value:
182 	/* Change the value unless we're actively driving the line. */
183 	if (!line->requested || line->dir == GPIO_LINE_DIRECTION_IN)
184 		__gpio_mockup_set(chip, offset, value);
185 
186 out:
187 	chip->lines[offset].pull = value;
188 	return ret;
189 }
190 
gpio_mockup_set_config(struct gpio_chip * gc,unsigned int offset,unsigned long config)191 static int gpio_mockup_set_config(struct gpio_chip *gc,
192 				  unsigned int offset, unsigned long config)
193 {
194 	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
195 
196 	switch (pinconf_to_config_param(config)) {
197 	case PIN_CONFIG_BIAS_PULL_UP:
198 		return gpio_mockup_apply_pull(chip, offset, 1);
199 	case PIN_CONFIG_BIAS_PULL_DOWN:
200 		return gpio_mockup_apply_pull(chip, offset, 0);
201 	default:
202 		break;
203 	}
204 	return -ENOTSUPP;
205 }
206 
gpio_mockup_dirout(struct gpio_chip * gc,unsigned int offset,int value)207 static int gpio_mockup_dirout(struct gpio_chip *gc,
208 			      unsigned int offset, int value)
209 {
210 	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
211 
212 	scoped_guard(mutex, &chip->lock) {
213 		chip->lines[offset].dir = GPIO_LINE_DIRECTION_OUT;
214 		__gpio_mockup_set(chip, offset, value);
215 	}
216 
217 	return 0;
218 }
219 
gpio_mockup_dirin(struct gpio_chip * gc,unsigned int offset)220 static int gpio_mockup_dirin(struct gpio_chip *gc, unsigned int offset)
221 {
222 	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
223 
224 	scoped_guard(mutex, &chip->lock)
225 		chip->lines[offset].dir = GPIO_LINE_DIRECTION_IN;
226 
227 	return 0;
228 }
229 
gpio_mockup_get_direction(struct gpio_chip * gc,unsigned int offset)230 static int gpio_mockup_get_direction(struct gpio_chip *gc, unsigned int offset)
231 {
232 	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
233 	int direction;
234 
235 	scoped_guard(mutex, &chip->lock)
236 		direction = chip->lines[offset].dir;
237 
238 	return direction;
239 }
240 
gpio_mockup_to_irq(struct gpio_chip * gc,unsigned int offset)241 static int gpio_mockup_to_irq(struct gpio_chip *gc, unsigned int offset)
242 {
243 	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
244 
245 	return irq_create_mapping(chip->irq_sim_domain, offset);
246 }
247 
gpio_mockup_request(struct gpio_chip * gc,unsigned int offset)248 static int gpio_mockup_request(struct gpio_chip *gc, unsigned int offset)
249 {
250 	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
251 
252 	scoped_guard(mutex, &chip->lock)
253 		chip->lines[offset].requested = true;
254 
255 	return 0;
256 }
257 
gpio_mockup_free(struct gpio_chip * gc,unsigned int offset)258 static void gpio_mockup_free(struct gpio_chip *gc, unsigned int offset)
259 {
260 	struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
261 
262 	guard(mutex)(&chip->lock);
263 
264 	chip->lines[offset].requested = false;
265 	__gpio_mockup_set(chip, offset, chip->lines[offset].pull);
266 }
267 
gpio_mockup_debugfs_read(struct file * file,char __user * usr_buf,size_t size,loff_t * ppos)268 static ssize_t gpio_mockup_debugfs_read(struct file *file,
269 					char __user *usr_buf,
270 					size_t size, loff_t *ppos)
271 {
272 	struct gpio_mockup_dbgfs_private *priv;
273 	struct gpio_mockup_chip *chip;
274 	struct seq_file *sfile;
275 	struct gpio_chip *gc;
276 	int val, cnt;
277 	char buf[3];
278 
279 	if (*ppos != 0)
280 		return 0;
281 
282 	sfile = file->private_data;
283 	priv = sfile->private;
284 	chip = priv->chip;
285 	gc = &chip->gc;
286 
287 	val = gpio_mockup_get(gc, priv->offset);
288 	cnt = snprintf(buf, sizeof(buf), "%d\n", val);
289 
290 	return simple_read_from_buffer(usr_buf, size, ppos, buf, cnt);
291 }
292 
gpio_mockup_debugfs_write(struct file * file,const char __user * usr_buf,size_t size,loff_t * ppos)293 static ssize_t gpio_mockup_debugfs_write(struct file *file,
294 					 const char __user *usr_buf,
295 					 size_t size, loff_t *ppos)
296 {
297 	struct gpio_mockup_dbgfs_private *priv;
298 	int rv, val;
299 	struct seq_file *sfile;
300 
301 	if (*ppos != 0)
302 		return -EINVAL;
303 
304 	rv = kstrtoint_from_user(usr_buf, size, 0, &val);
305 	if (rv)
306 		return rv;
307 	if (val != 0 && val != 1)
308 		return -EINVAL;
309 
310 	sfile = file->private_data;
311 	priv = sfile->private;
312 	rv = gpio_mockup_apply_pull(priv->chip, priv->offset, val);
313 	if (rv)
314 		return rv;
315 
316 	return size;
317 }
318 
gpio_mockup_debugfs_open(struct inode * inode,struct file * file)319 static int gpio_mockup_debugfs_open(struct inode *inode, struct file *file)
320 {
321 	return single_open(file, NULL, inode->i_private);
322 }
323 
324 /*
325  * Each mockup chip is represented by a directory named after the chip's device
326  * name under /sys/kernel/debug/gpio-mockup/. Each line is represented by
327  * a file using the line's offset as the name under the chip's directory.
328  *
329  * Reading from the line's file yields the current *value*, writing to the
330  * line's file changes the current *pull*. Default pull for mockup lines is
331  * down.
332  *
333  * Examples:
334  * - when a line pulled down is requested in output mode and driven high, its
335  *   value will return to 0 once it's released
336  * - when the line is requested in output mode and driven high, writing 0 to
337  *   the corresponding debugfs file will change the pull to down but the
338  *   reported value will still be 1 until the line is released
339  * - line requested in input mode always reports the same value as its pull
340  *   configuration
341  * - when the line is requested in input mode and monitored for events, writing
342  *   the same value to the debugfs file will be a noop, while writing the
343  *   opposite value will generate a dummy interrupt with an appropriate edge
344  */
345 static const struct file_operations gpio_mockup_debugfs_ops = {
346 	.owner = THIS_MODULE,
347 	.open = gpio_mockup_debugfs_open,
348 	.read = gpio_mockup_debugfs_read,
349 	.write = gpio_mockup_debugfs_write,
350 	.release = single_release,
351 };
352 
gpio_mockup_debugfs_setup(struct device * dev,struct gpio_mockup_chip * chip)353 static void gpio_mockup_debugfs_setup(struct device *dev,
354 				      struct gpio_mockup_chip *chip)
355 {
356 	struct gpio_mockup_dbgfs_private *priv;
357 	struct gpio_chip *gc;
358 	const char *devname;
359 	char *name;
360 	int i;
361 
362 	gc = &chip->gc;
363 
364 	/*
365 	 * There can only be a single GPIO device per platform device in
366 	 * gpio-mockup so using device_find_any_child() is OK.
367 	 */
368 	struct device *child __free(put_device) = device_find_any_child(dev);
369 	if (!child)
370 		return;
371 
372 	devname = dev_name(child);
373 	chip->dbg_dir = debugfs_create_dir(devname, gpio_mockup_dbg_dir);
374 
375 	for (i = 0; i < gc->ngpio; i++) {
376 		name = devm_kasprintf(dev, GFP_KERNEL, "%d", i);
377 		if (!name)
378 			return;
379 
380 		priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
381 		if (!priv)
382 			return;
383 
384 		priv->chip = chip;
385 		priv->offset = i;
386 
387 		debugfs_create_file(name, 0600, chip->dbg_dir, priv,
388 				    &gpio_mockup_debugfs_ops);
389 	}
390 }
391 
gpio_mockup_debugfs_cleanup(void * data)392 static void gpio_mockup_debugfs_cleanup(void *data)
393 {
394 	struct gpio_mockup_chip *chip = data;
395 
396 	debugfs_remove_recursive(chip->dbg_dir);
397 }
398 
gpio_mockup_dispose_mappings(void * data)399 static void gpio_mockup_dispose_mappings(void *data)
400 {
401 	struct gpio_mockup_chip *chip = data;
402 	struct gpio_chip *gc = &chip->gc;
403 	int i, irq;
404 
405 	for (i = 0; i < gc->ngpio; i++) {
406 		irq = irq_find_mapping(chip->irq_sim_domain, i);
407 		if (irq)
408 			irq_dispose_mapping(irq);
409 	}
410 }
411 
gpio_mockup_probe(struct platform_device * pdev)412 static int gpio_mockup_probe(struct platform_device *pdev)
413 {
414 	struct gpio_mockup_chip *chip;
415 	struct gpio_chip *gc;
416 	struct device *dev;
417 	const char *name;
418 	int rv, base, i;
419 	u16 ngpio;
420 
421 	dev = &pdev->dev;
422 
423 	rv = device_property_read_u32(dev, "gpio-base", &base);
424 	if (rv)
425 		base = -1;
426 
427 	rv = device_property_read_u16(dev, "nr-gpios", &ngpio);
428 	if (rv)
429 		return rv;
430 
431 	rv = device_property_read_string(dev, "chip-label", &name);
432 	if (rv)
433 		name = dev_name(dev);
434 
435 	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
436 	if (!chip)
437 		return -ENOMEM;
438 
439 	mutex_init(&chip->lock);
440 
441 	gc = &chip->gc;
442 	gc->base = base;
443 	gc->ngpio = ngpio;
444 	gc->label = name;
445 	gc->owner = THIS_MODULE;
446 	gc->parent = dev;
447 	gc->get = gpio_mockup_get;
448 	gc->set = gpio_mockup_set;
449 	gc->get_multiple = gpio_mockup_get_multiple;
450 	gc->set_multiple = gpio_mockup_set_multiple;
451 	gc->direction_output = gpio_mockup_dirout;
452 	gc->direction_input = gpio_mockup_dirin;
453 	gc->get_direction = gpio_mockup_get_direction;
454 	gc->set_config = gpio_mockup_set_config;
455 	gc->to_irq = gpio_mockup_to_irq;
456 	gc->request = gpio_mockup_request;
457 	gc->free = gpio_mockup_free;
458 
459 	chip->lines = devm_kcalloc(dev, gc->ngpio,
460 				   sizeof(*chip->lines), GFP_KERNEL);
461 	if (!chip->lines)
462 		return -ENOMEM;
463 
464 	for (i = 0; i < gc->ngpio; i++)
465 		chip->lines[i].dir = GPIO_LINE_DIRECTION_IN;
466 
467 	chip->irq_sim_domain = devm_irq_domain_create_sim(dev, NULL,
468 							  gc->ngpio);
469 	if (IS_ERR(chip->irq_sim_domain))
470 		return PTR_ERR(chip->irq_sim_domain);
471 
472 	rv = devm_add_action_or_reset(dev, gpio_mockup_dispose_mappings, chip);
473 	if (rv)
474 		return rv;
475 
476 	rv = devm_gpiochip_add_data(dev, &chip->gc, chip);
477 	if (rv)
478 		return rv;
479 
480 	gpio_mockup_debugfs_setup(dev, chip);
481 
482 	return devm_add_action_or_reset(dev, gpio_mockup_debugfs_cleanup, chip);
483 }
484 
485 static const struct of_device_id gpio_mockup_of_match[] = {
486 	{ .compatible = "gpio-mockup", },
487 	{},
488 };
489 MODULE_DEVICE_TABLE(of, gpio_mockup_of_match);
490 
491 static struct platform_driver gpio_mockup_driver = {
492 	.driver = {
493 		.name = "gpio-mockup",
494 		.of_match_table = gpio_mockup_of_match,
495 	},
496 	.probe = gpio_mockup_probe,
497 };
498 
499 static struct platform_device *gpio_mockup_pdevs[GPIO_MOCKUP_MAX_GC];
500 
gpio_mockup_unregister_pdevs(void)501 static void gpio_mockup_unregister_pdevs(void)
502 {
503 	struct platform_device *pdev;
504 	struct fwnode_handle *fwnode;
505 	int i;
506 
507 	for (i = 0; i < GPIO_MOCKUP_MAX_GC; i++) {
508 		pdev = gpio_mockup_pdevs[i];
509 		if (!pdev)
510 			continue;
511 
512 		fwnode = dev_fwnode(&pdev->dev);
513 		platform_device_unregister(pdev);
514 		fwnode_remove_software_node(fwnode);
515 	}
516 }
517 
gpio_mockup_register_chip(int idx)518 static int __init gpio_mockup_register_chip(int idx)
519 {
520 	struct property_entry properties[GPIO_MOCKUP_MAX_PROP];
521 	struct platform_device_info pdevinfo;
522 	struct platform_device *pdev;
523 	struct fwnode_handle *fwnode;
524 	char **line_names = NULL;
525 	char chip_label[32];
526 	int prop = 0, base;
527 	u16 ngpio;
528 
529 	memset(properties, 0, sizeof(properties));
530 	memset(&pdevinfo, 0, sizeof(pdevinfo));
531 
532 	snprintf(chip_label, sizeof(chip_label), "gpio-mockup-%c", idx + 'A');
533 	properties[prop++] = PROPERTY_ENTRY_STRING("chip-label", chip_label);
534 
535 	base = gpio_mockup_range_base(idx);
536 	if (base >= 0)
537 		properties[prop++] = PROPERTY_ENTRY_U32("gpio-base", base);
538 
539 	ngpio = base < 0 ? gpio_mockup_range_ngpio(idx)
540 			 : gpio_mockup_range_ngpio(idx) - base;
541 	properties[prop++] = PROPERTY_ENTRY_U16("nr-gpios", ngpio);
542 
543 	if (gpio_mockup_named_lines) {
544 		line_names = kasprintf_strarray(GFP_KERNEL, chip_label, ngpio);
545 		if (!line_names)
546 			return -ENOMEM;
547 
548 		properties[prop++] = PROPERTY_ENTRY_STRING_ARRAY_LEN(
549 					"gpio-line-names", line_names, ngpio);
550 	}
551 
552 	fwnode = fwnode_create_software_node(properties, NULL);
553 	if (IS_ERR(fwnode)) {
554 		kfree_strarray(line_names, ngpio);
555 		return PTR_ERR(fwnode);
556 	}
557 
558 	pdevinfo.name = "gpio-mockup";
559 	pdevinfo.id = idx;
560 	pdevinfo.fwnode = fwnode;
561 
562 	pdev = platform_device_register_full(&pdevinfo);
563 	kfree_strarray(line_names, ngpio);
564 	if (IS_ERR(pdev)) {
565 		fwnode_remove_software_node(fwnode);
566 		pr_err("error registering device");
567 		return PTR_ERR(pdev);
568 	}
569 
570 	gpio_mockup_pdevs[idx] = pdev;
571 
572 	return 0;
573 }
574 
gpio_mockup_init(void)575 static int __init gpio_mockup_init(void)
576 {
577 	int i, num_chips, err;
578 
579 	if ((gpio_mockup_num_ranges % 2) ||
580 	    (gpio_mockup_num_ranges > GPIO_MOCKUP_MAX_RANGES))
581 		return -EINVAL;
582 
583 	/* Each chip is described by two values. */
584 	num_chips = gpio_mockup_num_ranges / 2;
585 
586 	/*
587 	 * The second value in the <base GPIO - number of GPIOS> pair must
588 	 * always be greater than 0.
589 	 */
590 	for (i = 0; i < num_chips; i++) {
591 		if (gpio_mockup_range_ngpio(i) < 0)
592 			return -EINVAL;
593 	}
594 
595 	gpio_mockup_dbg_dir = debugfs_create_dir("gpio-mockup", NULL);
596 
597 	err = platform_driver_register(&gpio_mockup_driver);
598 	if (err) {
599 		pr_err("error registering platform driver\n");
600 		debugfs_remove_recursive(gpio_mockup_dbg_dir);
601 		return err;
602 	}
603 
604 	for (i = 0; i < num_chips; i++) {
605 		err = gpio_mockup_register_chip(i);
606 		if (err) {
607 			platform_driver_unregister(&gpio_mockup_driver);
608 			gpio_mockup_unregister_pdevs();
609 			debugfs_remove_recursive(gpio_mockup_dbg_dir);
610 			return err;
611 		}
612 	}
613 
614 	return 0;
615 }
616 
gpio_mockup_exit(void)617 static void __exit gpio_mockup_exit(void)
618 {
619 	gpio_mockup_unregister_pdevs();
620 	debugfs_remove_recursive(gpio_mockup_dbg_dir);
621 	platform_driver_unregister(&gpio_mockup_driver);
622 }
623 
624 module_init(gpio_mockup_init);
625 module_exit(gpio_mockup_exit);
626 
627 MODULE_AUTHOR("Kamlakant Patel <kamlakant.patel@broadcom.com>");
628 MODULE_AUTHOR("Bamvor Jian Zhang <bamv2005@gmail.com>");
629 MODULE_AUTHOR("Bartosz Golaszewski <brgl@bgdev.pl>");
630 MODULE_DESCRIPTION("GPIO Testing driver");
631 MODULE_LICENSE("GPL v2");
632