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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#include <linux/debugfs.h>
11#include <linux/gpio/consumer.h>
12#include <linux/gpio/driver.h>
13#include <linux/init.h>
14#include <linux/interrupt.h>
15#include <linux/irq.h>
16#include <linux/irq_sim.h>
17#include <linux/irqdomain.h>
18#include <linux/module.h>
19#include <linux/platform_device.h>
20#include <linux/property.h>
21#include <linux/slab.h>
22#include <linux/uaccess.h>
23
24#include "gpiolib.h"
25
26#define GPIO_MOCKUP_NAME "gpio-mockup"
27#define GPIO_MOCKUP_MAX_GC 10
28/*
29 * We're storing two values per chip: the GPIO base and the number
30 * of GPIO lines.
31 */
32#define GPIO_MOCKUP_MAX_RANGES (GPIO_MOCKUP_MAX_GC * 2)
33/* Maximum of three properties + the sentinel. */
34#define GPIO_MOCKUP_MAX_PROP 4
35
36#define gpio_mockup_err(...) pr_err(GPIO_MOCKUP_NAME ": " __VA_ARGS__)
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 */
43struct gpio_mockup_line_status {
44 int dir;
45 int value;
46 int pull;
47};
48
49struct gpio_mockup_chip {
50 struct gpio_chip gc;
51 struct gpio_mockup_line_status *lines;
52 struct irq_domain *irq_sim_domain;
53 struct dentry *dbg_dir;
54 struct mutex lock;
55};
56
57struct gpio_mockup_dbgfs_private {
58 struct gpio_mockup_chip *chip;
59 struct gpio_desc *desc;
60 unsigned int offset;
61};
62
63static int gpio_mockup_ranges[GPIO_MOCKUP_MAX_RANGES];
64static int gpio_mockup_num_ranges;
65module_param_array(gpio_mockup_ranges, int, &gpio_mockup_num_ranges, 0400);
66
67static bool gpio_mockup_named_lines;
68module_param_named(gpio_mockup_named_lines,
69 gpio_mockup_named_lines, bool, 0400);
70
71static struct dentry *gpio_mockup_dbg_dir;
72
73static int gpio_mockup_range_base(unsigned int index)
74{
75 return gpio_mockup_ranges[index * 2];
76}
77
78static int gpio_mockup_range_ngpio(unsigned int index)
79{
80 return gpio_mockup_ranges[index * 2 + 1];
81}
82
83static int __gpio_mockup_get(struct gpio_mockup_chip *chip,
84 unsigned int offset)
85{
86 return chip->lines[offset].value;
87}
88
89static int gpio_mockup_get(struct gpio_chip *gc, unsigned int offset)
90{
91 struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
92 int val;
93
94 mutex_lock(&chip->lock);
95 val = __gpio_mockup_get(chip, offset);
96 mutex_unlock(&chip->lock);
97
98 return val;
99}
100
101static int gpio_mockup_get_multiple(struct gpio_chip *gc,
102 unsigned long *mask, unsigned long *bits)
103{
104 struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
105 unsigned int bit, val;
106
107 mutex_lock(&chip->lock);
108 for_each_set_bit(bit, mask, gc->ngpio) {
109 val = __gpio_mockup_get(chip, bit);
110 __assign_bit(bit, bits, val);
111 }
112 mutex_unlock(&chip->lock);
113
114 return 0;
115}
116
117static void __gpio_mockup_set(struct gpio_mockup_chip *chip,
118 unsigned int offset, int value)
119{
120 chip->lines[offset].value = !!value;
121}
122
123static void gpio_mockup_set(struct gpio_chip *gc,
124 unsigned int offset, int value)
125{
126 struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
127
128 mutex_lock(&chip->lock);
129 __gpio_mockup_set(chip, offset, value);
130 mutex_unlock(&chip->lock);
131}
132
133static void gpio_mockup_set_multiple(struct gpio_chip *gc,
134 unsigned long *mask, unsigned long *bits)
135{
136 struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
137 unsigned int bit;
138
139 mutex_lock(&chip->lock);
140 for_each_set_bit(bit, mask, gc->ngpio)
141 __gpio_mockup_set(chip, bit, test_bit(bit, bits));
142 mutex_unlock(&chip->lock);
143}
144
145static int gpio_mockup_apply_pull(struct gpio_mockup_chip *chip,
146 unsigned int offset, int value)
147{
148 int curr, irq, irq_type, ret = 0;
149 struct gpio_desc *desc;
150 struct gpio_chip *gc;
151
152 gc = &chip->gc;
153 desc = &gc->gpiodev->descs[offset];
154
155 mutex_lock(&chip->lock);
156
157 if (test_bit(FLAG_REQUESTED, &desc->flags) &&
158 !test_bit(FLAG_IS_OUT, &desc->flags)) {
159 curr = __gpio_mockup_get(chip, offset);
160 if (curr == value)
161 goto out;
162
163 irq = irq_find_mapping(chip->irq_sim_domain, offset);
164 if (!irq)
165 /*
166 * This is fine - it just means, nobody is listening
167 * for interrupts on this line, otherwise
168 * irq_create_mapping() would have been called from
169 * the to_irq() callback.
170 */
171 goto set_value;
172
173 irq_type = irq_get_trigger_type(irq);
174
175 if ((value == 1 && (irq_type & IRQ_TYPE_EDGE_RISING)) ||
176 (value == 0 && (irq_type & IRQ_TYPE_EDGE_FALLING))) {
177 ret = irq_set_irqchip_state(irq, IRQCHIP_STATE_PENDING,
178 true);
179 if (ret)
180 goto out;
181 }
182 }
183
184set_value:
185 /* Change the value unless we're actively driving the line. */
186 if (!test_bit(FLAG_REQUESTED, &desc->flags) ||
187 !test_bit(FLAG_IS_OUT, &desc->flags))
188 __gpio_mockup_set(chip, offset, value);
189
190out:
191 chip->lines[offset].pull = value;
192 mutex_unlock(&chip->lock);
193 return ret;
194}
195
196static int gpio_mockup_set_config(struct gpio_chip *gc,
197 unsigned int offset, unsigned long config)
198{
199 struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
200
201 switch (pinconf_to_config_param(config)) {
202 case PIN_CONFIG_BIAS_PULL_UP:
203 return gpio_mockup_apply_pull(chip, offset, 1);
204 case PIN_CONFIG_BIAS_PULL_DOWN:
205 return gpio_mockup_apply_pull(chip, offset, 0);
206 default:
207 break;
208 }
209 return -ENOTSUPP;
210}
211
212static int gpio_mockup_dirout(struct gpio_chip *gc,
213 unsigned int offset, int value)
214{
215 struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
216
217 mutex_lock(&chip->lock);
218 chip->lines[offset].dir = GPIO_LINE_DIRECTION_OUT;
219 __gpio_mockup_set(chip, offset, value);
220 mutex_unlock(&chip->lock);
221
222 return 0;
223}
224
225static int gpio_mockup_dirin(struct gpio_chip *gc, unsigned int offset)
226{
227 struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
228
229 mutex_lock(&chip->lock);
230 chip->lines[offset].dir = GPIO_LINE_DIRECTION_IN;
231 mutex_unlock(&chip->lock);
232
233 return 0;
234}
235
236static int gpio_mockup_get_direction(struct gpio_chip *gc, unsigned int offset)
237{
238 struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
239 int direction;
240
241 mutex_lock(&chip->lock);
242 direction = chip->lines[offset].dir;
243 mutex_unlock(&chip->lock);
244
245 return direction;
246}
247
248static int gpio_mockup_to_irq(struct gpio_chip *gc, unsigned int offset)
249{
250 struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
251
252 return irq_create_mapping(chip->irq_sim_domain, offset);
253}
254
255static void gpio_mockup_free(struct gpio_chip *gc, unsigned int offset)
256{
257 struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
258
259 __gpio_mockup_set(chip, offset, chip->lines[offset].pull);
260}
261
262static ssize_t gpio_mockup_debugfs_read(struct file *file,
263 char __user *usr_buf,
264 size_t size, loff_t *ppos)
265{
266 struct gpio_mockup_dbgfs_private *priv;
267 struct gpio_mockup_chip *chip;
268 struct seq_file *sfile;
269 struct gpio_chip *gc;
270 int val, cnt;
271 char buf[3];
272
273 if (*ppos != 0)
274 return 0;
275
276 sfile = file->private_data;
277 priv = sfile->private;
278 chip = priv->chip;
279 gc = &chip->gc;
280
281 val = gpio_mockup_get(gc, priv->offset);
282 cnt = snprintf(buf, sizeof(buf), "%d\n", val);
283
284 return simple_read_from_buffer(usr_buf, size, ppos, buf, cnt);
285}
286
287static ssize_t gpio_mockup_debugfs_write(struct file *file,
288 const char __user *usr_buf,
289 size_t size, loff_t *ppos)
290{
291 struct gpio_mockup_dbgfs_private *priv;
292 int rv, val;
293 struct seq_file *sfile;
294
295 if (*ppos != 0)
296 return -EINVAL;
297
298 rv = kstrtoint_from_user(usr_buf, size, 0, &val);
299 if (rv)
300 return rv;
301 if (val != 0 && val != 1)
302 return -EINVAL;
303
304 sfile = file->private_data;
305 priv = sfile->private;
306 rv = gpio_mockup_apply_pull(priv->chip, priv->offset, val);
307 if (rv)
308 return rv;
309
310 return size;
311}
312
313static int gpio_mockup_debugfs_open(struct inode *inode, struct file *file)
314{
315 return single_open(file, NULL, inode->i_private);
316}
317
318/*
319 * Each mockup chip is represented by a directory named after the chip's device
320 * name under /sys/kernel/debug/gpio-mockup/. Each line is represented by
321 * a file using the line's offset as the name under the chip's directory.
322 *
323 * Reading from the line's file yields the current *value*, writing to the
324 * line's file changes the current *pull*. Default pull for mockup lines is
325 * down.
326 *
327 * Examples:
328 * - when a line pulled down is requested in output mode and driven high, its
329 * value will return to 0 once it's released
330 * - when the line is requested in output mode and driven high, writing 0 to
331 * the corresponding debugfs file will change the pull to down but the
332 * reported value will still be 1 until the line is released
333 * - line requested in input mode always reports the same value as its pull
334 * configuration
335 * - when the line is requested in input mode and monitored for events, writing
336 * the same value to the debugfs file will be a noop, while writing the
337 * opposite value will generate a dummy interrupt with an appropriate edge
338 */
339static const struct file_operations gpio_mockup_debugfs_ops = {
340 .owner = THIS_MODULE,
341 .open = gpio_mockup_debugfs_open,
342 .read = gpio_mockup_debugfs_read,
343 .write = gpio_mockup_debugfs_write,
344 .llseek = no_llseek,
345 .release = single_release,
346};
347
348static void gpio_mockup_debugfs_setup(struct device *dev,
349 struct gpio_mockup_chip *chip)
350{
351 struct gpio_mockup_dbgfs_private *priv;
352 struct gpio_chip *gc;
353 const char *devname;
354 char *name;
355 int i;
356
357 gc = &chip->gc;
358 devname = dev_name(&gc->gpiodev->dev);
359
360 chip->dbg_dir = debugfs_create_dir(devname, gpio_mockup_dbg_dir);
361
362 for (i = 0; i < gc->ngpio; i++) {
363 name = devm_kasprintf(dev, GFP_KERNEL, "%d", i);
364 if (!name)
365 return;
366
367 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
368 if (!priv)
369 return;
370
371 priv->chip = chip;
372 priv->offset = i;
373 priv->desc = &gc->gpiodev->descs[i];
374
375 debugfs_create_file(name, 0200, chip->dbg_dir, priv,
376 &gpio_mockup_debugfs_ops);
377 }
378
379 return;
380}
381
382static int gpio_mockup_name_lines(struct device *dev,
383 struct gpio_mockup_chip *chip)
384{
385 struct gpio_chip *gc = &chip->gc;
386 char **names;
387 int i;
388
389 names = devm_kcalloc(dev, gc->ngpio, sizeof(char *), GFP_KERNEL);
390 if (!names)
391 return -ENOMEM;
392
393 for (i = 0; i < gc->ngpio; i++) {
394 names[i] = devm_kasprintf(dev, GFP_KERNEL,
395 "%s-%d", gc->label, i);
396 if (!names[i])
397 return -ENOMEM;
398 }
399
400 gc->names = (const char *const *)names;
401
402 return 0;
403}
404
405static void gpio_mockup_dispose_mappings(void *data)
406{
407 struct gpio_mockup_chip *chip = data;
408 struct gpio_chip *gc = &chip->gc;
409 int i, irq;
410
411 for (i = 0; i < gc->ngpio; i++) {
412 irq = irq_find_mapping(chip->irq_sim_domain, i);
413 if (irq)
414 irq_dispose_mapping(irq);
415 }
416}
417
418static int gpio_mockup_probe(struct platform_device *pdev)
419{
420 struct gpio_mockup_chip *chip;
421 struct gpio_chip *gc;
422 struct device *dev;
423 const char *name;
424 int rv, base, i;
425 u16 ngpio;
426
427 dev = &pdev->dev;
428
429 rv = device_property_read_u32(dev, "gpio-base", &base);
430 if (rv)
431 base = -1;
432
433 rv = device_property_read_u16(dev, "nr-gpios", &ngpio);
434 if (rv)
435 return rv;
436
437 rv = device_property_read_string(dev, "chip-name", &name);
438 if (rv)
439 name = NULL;
440
441 chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
442 if (!chip)
443 return -ENOMEM;
444
445 if (!name) {
446 name = devm_kasprintf(dev, GFP_KERNEL,
447 "%s-%c", pdev->name, pdev->id + 'A');
448 if (!name)
449 return -ENOMEM;
450 }
451
452 mutex_init(&chip->lock);
453
454 gc = &chip->gc;
455 gc->base = base;
456 gc->ngpio = ngpio;
457 gc->label = name;
458 gc->owner = THIS_MODULE;
459 gc->parent = dev;
460 gc->get = gpio_mockup_get;
461 gc->set = gpio_mockup_set;
462 gc->get_multiple = gpio_mockup_get_multiple;
463 gc->set_multiple = gpio_mockup_set_multiple;
464 gc->direction_output = gpio_mockup_dirout;
465 gc->direction_input = gpio_mockup_dirin;
466 gc->get_direction = gpio_mockup_get_direction;
467 gc->set_config = gpio_mockup_set_config;
468 gc->to_irq = gpio_mockup_to_irq;
469 gc->free = gpio_mockup_free;
470
471 chip->lines = devm_kcalloc(dev, gc->ngpio,
472 sizeof(*chip->lines), GFP_KERNEL);
473 if (!chip->lines)
474 return -ENOMEM;
475
476 for (i = 0; i < gc->ngpio; i++)
477 chip->lines[i].dir = GPIO_LINE_DIRECTION_IN;
478
479 if (device_property_read_bool(dev, "named-gpio-lines")) {
480 rv = gpio_mockup_name_lines(dev, chip);
481 if (rv)
482 return rv;
483 }
484
485 chip->irq_sim_domain = devm_irq_domain_create_sim(dev, NULL,
486 gc->ngpio);
487 if (IS_ERR(chip->irq_sim_domain))
488 return PTR_ERR(chip->irq_sim_domain);
489
490 rv = devm_add_action_or_reset(dev, gpio_mockup_dispose_mappings, chip);
491 if (rv)
492 return rv;
493
494 rv = devm_gpiochip_add_data(dev, &chip->gc, chip);
495 if (rv)
496 return rv;
497
498 gpio_mockup_debugfs_setup(dev, chip);
499
500 return 0;
501}
502
503static struct platform_driver gpio_mockup_driver = {
504 .driver = {
505 .name = GPIO_MOCKUP_NAME,
506 },
507 .probe = gpio_mockup_probe,
508};
509
510static struct platform_device *gpio_mockup_pdevs[GPIO_MOCKUP_MAX_GC];
511
512static void gpio_mockup_unregister_pdevs(void)
513{
514 struct platform_device *pdev;
515 int i;
516
517 for (i = 0; i < GPIO_MOCKUP_MAX_GC; i++) {
518 pdev = gpio_mockup_pdevs[i];
519
520 if (pdev)
521 platform_device_unregister(pdev);
522 }
523}
524
525static int __init gpio_mockup_init(void)
526{
527 struct property_entry properties[GPIO_MOCKUP_MAX_PROP];
528 int i, prop, num_chips, err = 0, base;
529 struct platform_device_info pdevinfo;
530 struct platform_device *pdev;
531 u16 ngpio;
532
533 if ((gpio_mockup_num_ranges < 2) ||
534 (gpio_mockup_num_ranges % 2) ||
535 (gpio_mockup_num_ranges > GPIO_MOCKUP_MAX_RANGES))
536 return -EINVAL;
537
538 /* Each chip is described by two values. */
539 num_chips = gpio_mockup_num_ranges / 2;
540
541 /*
542 * The second value in the <base GPIO - number of GPIOS> pair must
543 * always be greater than 0.
544 */
545 for (i = 0; i < num_chips; i++) {
546 if (gpio_mockup_range_ngpio(i) < 0)
547 return -EINVAL;
548 }
549
550 gpio_mockup_dbg_dir = debugfs_create_dir("gpio-mockup", NULL);
551
552 err = platform_driver_register(&gpio_mockup_driver);
553 if (err) {
554 gpio_mockup_err("error registering platform driver\n");
555 debugfs_remove_recursive(gpio_mockup_dbg_dir);
556 return err;
557 }
558
559 for (i = 0; i < num_chips; i++) {
560 memset(properties, 0, sizeof(properties));
561 memset(&pdevinfo, 0, sizeof(pdevinfo));
562 prop = 0;
563
564 base = gpio_mockup_range_base(i);
565 if (base >= 0)
566 properties[prop++] = PROPERTY_ENTRY_U32("gpio-base",
567 base);
568
569 ngpio = base < 0 ? gpio_mockup_range_ngpio(i)
570 : gpio_mockup_range_ngpio(i) - base;
571 properties[prop++] = PROPERTY_ENTRY_U16("nr-gpios", ngpio);
572
573 if (gpio_mockup_named_lines)
574 properties[prop++] = PROPERTY_ENTRY_BOOL(
575 "named-gpio-lines");
576
577 pdevinfo.name = GPIO_MOCKUP_NAME;
578 pdevinfo.id = i;
579 pdevinfo.properties = properties;
580
581 pdev = platform_device_register_full(&pdevinfo);
582 if (IS_ERR(pdev)) {
583 gpio_mockup_err("error registering device");
584 platform_driver_unregister(&gpio_mockup_driver);
585 gpio_mockup_unregister_pdevs();
586 debugfs_remove_recursive(gpio_mockup_dbg_dir);
587 return PTR_ERR(pdev);
588 }
589
590 gpio_mockup_pdevs[i] = pdev;
591 }
592
593 return 0;
594}
595
596static void __exit gpio_mockup_exit(void)
597{
598 debugfs_remove_recursive(gpio_mockup_dbg_dir);
599 platform_driver_unregister(&gpio_mockup_driver);
600 gpio_mockup_unregister_pdevs();
601}
602
603module_init(gpio_mockup_init);
604module_exit(gpio_mockup_exit);
605
606MODULE_AUTHOR("Kamlakant Patel <kamlakant.patel@broadcom.com>");
607MODULE_AUTHOR("Bamvor Jian Zhang <bamv2005@gmail.com>");
608MODULE_AUTHOR("Bartosz Golaszewski <brgl@bgdev.pl>");
609MODULE_DESCRIPTION("GPIO Testing driver");
610MODULE_LICENSE("GPL v2");
1/*
2 * GPIO Testing Device Driver
3 *
4 * Copyright (C) 2014 Kamlakant Patel <kamlakant.patel@broadcom.com>
5 * Copyright (C) 2015-2016 Bamvor Jian Zhang <bamv2005@gmail.com>
6 * Copyright (C) 2017 Bartosz Golaszewski <brgl@bgdev.pl>
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the
10 * Free Software Foundation; either version 2 of the License, or (at your
11 * option) any later version.
12 *
13 */
14
15#include <linux/init.h>
16#include <linux/module.h>
17#include <linux/gpio/driver.h>
18#include <linux/gpio/consumer.h>
19#include <linux/platform_device.h>
20#include <linux/slab.h>
21#include <linux/interrupt.h>
22#include <linux/irq.h>
23#include <linux/irq_sim.h>
24#include <linux/debugfs.h>
25#include <linux/uaccess.h>
26
27#include "gpiolib.h"
28
29#define GPIO_MOCKUP_NAME "gpio-mockup"
30#define GPIO_MOCKUP_MAX_GC 10
31/*
32 * We're storing two values per chip: the GPIO base and the number
33 * of GPIO lines.
34 */
35#define GPIO_MOCKUP_MAX_RANGES (GPIO_MOCKUP_MAX_GC * 2)
36
37#define gpio_mockup_err(...) pr_err(GPIO_MOCKUP_NAME ": " __VA_ARGS__)
38
39enum {
40 GPIO_MOCKUP_DIR_OUT = 0,
41 GPIO_MOCKUP_DIR_IN = 1,
42};
43
44/*
45 * struct gpio_pin_status - structure describing a GPIO status
46 * @dir: Configures direction of gpio as "in" or "out", 0=in, 1=out
47 * @value: Configures status of the gpio as 0(low) or 1(high)
48 */
49struct gpio_mockup_line_status {
50 int dir;
51 int value;
52};
53
54struct gpio_mockup_chip {
55 struct gpio_chip gc;
56 struct gpio_mockup_line_status *lines;
57 struct irq_sim irqsim;
58 struct dentry *dbg_dir;
59};
60
61struct gpio_mockup_dbgfs_private {
62 struct gpio_mockup_chip *chip;
63 struct gpio_desc *desc;
64 int offset;
65};
66
67struct gpio_mockup_platform_data {
68 int base;
69 int ngpio;
70 int index;
71 bool named_lines;
72};
73
74static int gpio_mockup_ranges[GPIO_MOCKUP_MAX_RANGES];
75static int gpio_mockup_num_ranges;
76module_param_array(gpio_mockup_ranges, int, &gpio_mockup_num_ranges, 0400);
77
78static bool gpio_mockup_named_lines;
79module_param_named(gpio_mockup_named_lines,
80 gpio_mockup_named_lines, bool, 0400);
81
82static struct dentry *gpio_mockup_dbg_dir;
83
84static int gpio_mockup_range_base(unsigned int index)
85{
86 return gpio_mockup_ranges[index * 2];
87}
88
89static int gpio_mockup_range_ngpio(unsigned int index)
90{
91 return gpio_mockup_ranges[index * 2 + 1];
92}
93
94static int gpio_mockup_get(struct gpio_chip *gc, unsigned int offset)
95{
96 struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
97
98 return chip->lines[offset].value;
99}
100
101static void gpio_mockup_set(struct gpio_chip *gc,
102 unsigned int offset, int value)
103{
104 struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
105
106 chip->lines[offset].value = !!value;
107}
108
109static void gpio_mockup_set_multiple(struct gpio_chip *gc,
110 unsigned long *mask, unsigned long *bits)
111{
112 unsigned int bit;
113
114 for_each_set_bit(bit, mask, gc->ngpio)
115 gpio_mockup_set(gc, bit, test_bit(bit, bits));
116
117}
118
119static int gpio_mockup_dirout(struct gpio_chip *gc,
120 unsigned int offset, int value)
121{
122 struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
123
124 gpio_mockup_set(gc, offset, value);
125 chip->lines[offset].dir = GPIO_MOCKUP_DIR_OUT;
126
127 return 0;
128}
129
130static int gpio_mockup_dirin(struct gpio_chip *gc, unsigned int offset)
131{
132 struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
133
134 chip->lines[offset].dir = GPIO_MOCKUP_DIR_IN;
135
136 return 0;
137}
138
139static int gpio_mockup_get_direction(struct gpio_chip *gc, unsigned int offset)
140{
141 struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
142
143 return chip->lines[offset].dir;
144}
145
146static int gpio_mockup_to_irq(struct gpio_chip *gc, unsigned int offset)
147{
148 struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
149
150 return irq_sim_irqnum(&chip->irqsim, offset);
151}
152
153static ssize_t gpio_mockup_event_write(struct file *file,
154 const char __user *usr_buf,
155 size_t size, loff_t *ppos)
156{
157 struct gpio_mockup_dbgfs_private *priv;
158 struct gpio_mockup_chip *chip;
159 struct seq_file *sfile;
160 struct gpio_desc *desc;
161 int rv, val;
162
163 rv = kstrtoint_from_user(usr_buf, size, 0, &val);
164 if (rv)
165 return rv;
166 if (val != 0 && val != 1)
167 return -EINVAL;
168
169 sfile = file->private_data;
170 priv = sfile->private;
171 desc = priv->desc;
172 chip = priv->chip;
173
174 gpiod_set_value_cansleep(desc, val);
175 irq_sim_fire(&chip->irqsim, priv->offset);
176
177 return size;
178}
179
180static int gpio_mockup_event_open(struct inode *inode, struct file *file)
181{
182 return single_open(file, NULL, inode->i_private);
183}
184
185static const struct file_operations gpio_mockup_event_ops = {
186 .owner = THIS_MODULE,
187 .open = gpio_mockup_event_open,
188 .write = gpio_mockup_event_write,
189 .llseek = no_llseek,
190};
191
192static void gpio_mockup_debugfs_setup(struct device *dev,
193 struct gpio_mockup_chip *chip)
194{
195 struct gpio_mockup_dbgfs_private *priv;
196 struct dentry *evfile, *link;
197 struct gpio_chip *gc;
198 const char *devname;
199 char *name;
200 int i;
201
202 gc = &chip->gc;
203 devname = dev_name(&gc->gpiodev->dev);
204
205 chip->dbg_dir = debugfs_create_dir(devname, gpio_mockup_dbg_dir);
206 if (IS_ERR_OR_NULL(chip->dbg_dir))
207 goto err;
208
209 link = debugfs_create_symlink(gc->label, gpio_mockup_dbg_dir, devname);
210 if (IS_ERR_OR_NULL(link))
211 goto err;
212
213 for (i = 0; i < gc->ngpio; i++) {
214 name = devm_kasprintf(dev, GFP_KERNEL, "%d", i);
215 if (!name)
216 goto err;
217
218 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
219 if (!priv)
220 goto err;
221
222 priv->chip = chip;
223 priv->offset = i;
224 priv->desc = &gc->gpiodev->descs[i];
225
226 evfile = debugfs_create_file(name, 0200, chip->dbg_dir, priv,
227 &gpio_mockup_event_ops);
228 if (IS_ERR_OR_NULL(evfile))
229 goto err;
230 }
231
232 return;
233
234err:
235 dev_err(dev, "error creating debugfs event files\n");
236}
237
238static int gpio_mockup_name_lines(struct device *dev,
239 struct gpio_mockup_chip *chip)
240{
241 struct gpio_chip *gc = &chip->gc;
242 char **names;
243 int i;
244
245 names = devm_kcalloc(dev, gc->ngpio, sizeof(char *), GFP_KERNEL);
246 if (!names)
247 return -ENOMEM;
248
249 for (i = 0; i < gc->ngpio; i++) {
250 names[i] = devm_kasprintf(dev, GFP_KERNEL,
251 "%s-%d", gc->label, i);
252 if (!names[i])
253 return -ENOMEM;
254 }
255
256 gc->names = (const char *const *)names;
257
258 return 0;
259}
260
261static int gpio_mockup_probe(struct platform_device *pdev)
262{
263 struct gpio_mockup_platform_data *pdata;
264 struct gpio_mockup_chip *chip;
265 struct gpio_chip *gc;
266 int rv, base, ngpio;
267 struct device *dev;
268 char *name;
269
270 dev = &pdev->dev;
271 pdata = dev_get_platdata(dev);
272 base = pdata->base;
273 ngpio = pdata->ngpio;
274
275 chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
276 if (!chip)
277 return -ENOMEM;
278
279 name = devm_kasprintf(dev, GFP_KERNEL, "%s-%c",
280 pdev->name, pdata->index);
281 if (!name)
282 return -ENOMEM;
283
284 gc = &chip->gc;
285 gc->base = base;
286 gc->ngpio = ngpio;
287 gc->label = name;
288 gc->owner = THIS_MODULE;
289 gc->parent = dev;
290 gc->get = gpio_mockup_get;
291 gc->set = gpio_mockup_set;
292 gc->set_multiple = gpio_mockup_set_multiple;
293 gc->direction_output = gpio_mockup_dirout;
294 gc->direction_input = gpio_mockup_dirin;
295 gc->get_direction = gpio_mockup_get_direction;
296 gc->to_irq = gpio_mockup_to_irq;
297
298 chip->lines = devm_kcalloc(dev, gc->ngpio,
299 sizeof(*chip->lines), GFP_KERNEL);
300 if (!chip->lines)
301 return -ENOMEM;
302
303 if (pdata->named_lines) {
304 rv = gpio_mockup_name_lines(dev, chip);
305 if (rv)
306 return rv;
307 }
308
309 rv = devm_irq_sim_init(dev, &chip->irqsim, gc->ngpio);
310 if (rv < 0)
311 return rv;
312
313 rv = devm_gpiochip_add_data(dev, &chip->gc, chip);
314 if (rv)
315 return rv;
316
317 if (!IS_ERR_OR_NULL(gpio_mockup_dbg_dir))
318 gpio_mockup_debugfs_setup(dev, chip);
319
320 return 0;
321}
322
323static struct platform_driver gpio_mockup_driver = {
324 .driver = {
325 .name = GPIO_MOCKUP_NAME,
326 },
327 .probe = gpio_mockup_probe,
328};
329
330static struct platform_device *gpio_mockup_pdevs[GPIO_MOCKUP_MAX_GC];
331
332static void gpio_mockup_unregister_pdevs(void)
333{
334 struct platform_device *pdev;
335 int i;
336
337 for (i = 0; i < GPIO_MOCKUP_MAX_GC; i++) {
338 pdev = gpio_mockup_pdevs[i];
339
340 if (pdev)
341 platform_device_unregister(pdev);
342 }
343}
344
345static int __init gpio_mockup_init(void)
346{
347 int i, num_chips, err = 0, index = 'A';
348 struct gpio_mockup_platform_data pdata;
349 struct platform_device *pdev;
350
351 if ((gpio_mockup_num_ranges < 2) ||
352 (gpio_mockup_num_ranges % 2) ||
353 (gpio_mockup_num_ranges > GPIO_MOCKUP_MAX_RANGES))
354 return -EINVAL;
355
356 /* Each chip is described by two values. */
357 num_chips = gpio_mockup_num_ranges / 2;
358
359 /*
360 * The second value in the <base GPIO - number of GPIOS> pair must
361 * always be greater than 0.
362 */
363 for (i = 0; i < num_chips; i++) {
364 if (gpio_mockup_range_ngpio(i) < 0)
365 return -EINVAL;
366 }
367
368 gpio_mockup_dbg_dir = debugfs_create_dir("gpio-mockup-event", NULL);
369 if (IS_ERR_OR_NULL(gpio_mockup_dbg_dir))
370 gpio_mockup_err("error creating debugfs directory\n");
371
372 err = platform_driver_register(&gpio_mockup_driver);
373 if (err) {
374 gpio_mockup_err("error registering platform driver\n");
375 return err;
376 }
377
378 for (i = 0; i < num_chips; i++) {
379 pdata.index = index++;
380 pdata.base = gpio_mockup_range_base(i);
381 pdata.ngpio = pdata.base < 0
382 ? gpio_mockup_range_ngpio(i)
383 : gpio_mockup_range_ngpio(i) - pdata.base;
384 pdata.named_lines = gpio_mockup_named_lines;
385
386 pdev = platform_device_register_resndata(NULL,
387 GPIO_MOCKUP_NAME,
388 i, NULL, 0, &pdata,
389 sizeof(pdata));
390 if (IS_ERR(pdev)) {
391 gpio_mockup_err("error registering device");
392 platform_driver_unregister(&gpio_mockup_driver);
393 gpio_mockup_unregister_pdevs();
394 return PTR_ERR(pdev);
395 }
396
397 gpio_mockup_pdevs[i] = pdev;
398 }
399
400 return 0;
401}
402
403static void __exit gpio_mockup_exit(void)
404{
405 debugfs_remove_recursive(gpio_mockup_dbg_dir);
406 platform_driver_unregister(&gpio_mockup_driver);
407 gpio_mockup_unregister_pdevs();
408}
409
410module_init(gpio_mockup_init);
411module_exit(gpio_mockup_exit);
412
413MODULE_AUTHOR("Kamlakant Patel <kamlakant.patel@broadcom.com>");
414MODULE_AUTHOR("Bamvor Jian Zhang <bamv2005@gmail.com>");
415MODULE_AUTHOR("Bartosz Golaszewski <brgl@bgdev.pl>");
416MODULE_DESCRIPTION("GPIO Testing driver");
417MODULE_LICENSE("GPL v2");