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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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12#include <linux/debugfs.h>
13#include <linux/gpio/driver.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/mod_devicetable.h>
19#include <linux/module.h>
20#include <linux/platform_device.h>
21#include <linux/property.h>
22#include <linux/seq_file.h>
23#include <linux/slab.h>
24#include <linux/string_helpers.h>
25#include <linux/uaccess.h>
26
27#include "gpiolib.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 */
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 struct gpio_chip *gc = &chip->gc;
149 struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
150 int curr, irq, irq_type, ret = 0;
151
152 mutex_lock(&chip->lock);
153
154 if (test_bit(FLAG_REQUESTED, &desc->flags) &&
155 !test_bit(FLAG_IS_OUT, &desc->flags)) {
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
181set_value:
182 /* Change the value unless we're actively driving the line. */
183 if (!test_bit(FLAG_REQUESTED, &desc->flags) ||
184 !test_bit(FLAG_IS_OUT, &desc->flags))
185 __gpio_mockup_set(chip, offset, value);
186
187out:
188 chip->lines[offset].pull = value;
189 mutex_unlock(&chip->lock);
190 return ret;
191}
192
193static int gpio_mockup_set_config(struct gpio_chip *gc,
194 unsigned int offset, unsigned long config)
195{
196 struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
197
198 switch (pinconf_to_config_param(config)) {
199 case PIN_CONFIG_BIAS_PULL_UP:
200 return gpio_mockup_apply_pull(chip, offset, 1);
201 case PIN_CONFIG_BIAS_PULL_DOWN:
202 return gpio_mockup_apply_pull(chip, offset, 0);
203 default:
204 break;
205 }
206 return -ENOTSUPP;
207}
208
209static int gpio_mockup_dirout(struct gpio_chip *gc,
210 unsigned int offset, int value)
211{
212 struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
213
214 mutex_lock(&chip->lock);
215 chip->lines[offset].dir = GPIO_LINE_DIRECTION_OUT;
216 __gpio_mockup_set(chip, offset, value);
217 mutex_unlock(&chip->lock);
218
219 return 0;
220}
221
222static int gpio_mockup_dirin(struct gpio_chip *gc, unsigned int offset)
223{
224 struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
225
226 mutex_lock(&chip->lock);
227 chip->lines[offset].dir = GPIO_LINE_DIRECTION_IN;
228 mutex_unlock(&chip->lock);
229
230 return 0;
231}
232
233static int gpio_mockup_get_direction(struct gpio_chip *gc, unsigned int offset)
234{
235 struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
236 int direction;
237
238 mutex_lock(&chip->lock);
239 direction = chip->lines[offset].dir;
240 mutex_unlock(&chip->lock);
241
242 return direction;
243}
244
245static int gpio_mockup_to_irq(struct gpio_chip *gc, unsigned int offset)
246{
247 struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
248
249 return irq_create_mapping(chip->irq_sim_domain, offset);
250}
251
252static void gpio_mockup_free(struct gpio_chip *gc, unsigned int offset)
253{
254 struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
255
256 __gpio_mockup_set(chip, offset, chip->lines[offset].pull);
257}
258
259static ssize_t gpio_mockup_debugfs_read(struct file *file,
260 char __user *usr_buf,
261 size_t size, loff_t *ppos)
262{
263 struct gpio_mockup_dbgfs_private *priv;
264 struct gpio_mockup_chip *chip;
265 struct seq_file *sfile;
266 struct gpio_chip *gc;
267 int val, cnt;
268 char buf[3];
269
270 if (*ppos != 0)
271 return 0;
272
273 sfile = file->private_data;
274 priv = sfile->private;
275 chip = priv->chip;
276 gc = &chip->gc;
277
278 val = gpio_mockup_get(gc, priv->offset);
279 cnt = snprintf(buf, sizeof(buf), "%d\n", val);
280
281 return simple_read_from_buffer(usr_buf, size, ppos, buf, cnt);
282}
283
284static ssize_t gpio_mockup_debugfs_write(struct file *file,
285 const char __user *usr_buf,
286 size_t size, loff_t *ppos)
287{
288 struct gpio_mockup_dbgfs_private *priv;
289 int rv, val;
290 struct seq_file *sfile;
291
292 if (*ppos != 0)
293 return -EINVAL;
294
295 rv = kstrtoint_from_user(usr_buf, size, 0, &val);
296 if (rv)
297 return rv;
298 if (val != 0 && val != 1)
299 return -EINVAL;
300
301 sfile = file->private_data;
302 priv = sfile->private;
303 rv = gpio_mockup_apply_pull(priv->chip, priv->offset, val);
304 if (rv)
305 return rv;
306
307 return size;
308}
309
310static int gpio_mockup_debugfs_open(struct inode *inode, struct file *file)
311{
312 return single_open(file, NULL, inode->i_private);
313}
314
315/*
316 * Each mockup chip is represented by a directory named after the chip's device
317 * name under /sys/kernel/debug/gpio-mockup/. Each line is represented by
318 * a file using the line's offset as the name under the chip's directory.
319 *
320 * Reading from the line's file yields the current *value*, writing to the
321 * line's file changes the current *pull*. Default pull for mockup lines is
322 * down.
323 *
324 * Examples:
325 * - when a line pulled down is requested in output mode and driven high, its
326 * value will return to 0 once it's released
327 * - when the line is requested in output mode and driven high, writing 0 to
328 * the corresponding debugfs file will change the pull to down but the
329 * reported value will still be 1 until the line is released
330 * - line requested in input mode always reports the same value as its pull
331 * configuration
332 * - when the line is requested in input mode and monitored for events, writing
333 * the same value to the debugfs file will be a noop, while writing the
334 * opposite value will generate a dummy interrupt with an appropriate edge
335 */
336static const struct file_operations gpio_mockup_debugfs_ops = {
337 .owner = THIS_MODULE,
338 .open = gpio_mockup_debugfs_open,
339 .read = gpio_mockup_debugfs_read,
340 .write = gpio_mockup_debugfs_write,
341 .llseek = no_llseek,
342 .release = single_release,
343};
344
345static void gpio_mockup_debugfs_setup(struct device *dev,
346 struct gpio_mockup_chip *chip)
347{
348 struct gpio_mockup_dbgfs_private *priv;
349 struct gpio_chip *gc;
350 const char *devname;
351 char *name;
352 int i;
353
354 gc = &chip->gc;
355 devname = dev_name(&gc->gpiodev->dev);
356
357 chip->dbg_dir = debugfs_create_dir(devname, gpio_mockup_dbg_dir);
358
359 for (i = 0; i < gc->ngpio; i++) {
360 name = devm_kasprintf(dev, GFP_KERNEL, "%d", i);
361 if (!name)
362 return;
363
364 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
365 if (!priv)
366 return;
367
368 priv->chip = chip;
369 priv->offset = i;
370 priv->desc = gpiochip_get_desc(gc, i);
371
372 debugfs_create_file(name, 0200, chip->dbg_dir, priv,
373 &gpio_mockup_debugfs_ops);
374 }
375}
376
377static void gpio_mockup_debugfs_cleanup(void *data)
378{
379 struct gpio_mockup_chip *chip = data;
380
381 debugfs_remove_recursive(chip->dbg_dir);
382}
383
384static void gpio_mockup_dispose_mappings(void *data)
385{
386 struct gpio_mockup_chip *chip = data;
387 struct gpio_chip *gc = &chip->gc;
388 int i, irq;
389
390 for (i = 0; i < gc->ngpio; i++) {
391 irq = irq_find_mapping(chip->irq_sim_domain, i);
392 if (irq)
393 irq_dispose_mapping(irq);
394 }
395}
396
397static int gpio_mockup_probe(struct platform_device *pdev)
398{
399 struct gpio_mockup_chip *chip;
400 struct gpio_chip *gc;
401 struct device *dev;
402 const char *name;
403 int rv, base, i;
404 u16 ngpio;
405
406 dev = &pdev->dev;
407
408 rv = device_property_read_u32(dev, "gpio-base", &base);
409 if (rv)
410 base = -1;
411
412 rv = device_property_read_u16(dev, "nr-gpios", &ngpio);
413 if (rv)
414 return rv;
415
416 rv = device_property_read_string(dev, "chip-label", &name);
417 if (rv)
418 name = dev_name(dev);
419
420 chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
421 if (!chip)
422 return -ENOMEM;
423
424 mutex_init(&chip->lock);
425
426 gc = &chip->gc;
427 gc->base = base;
428 gc->ngpio = ngpio;
429 gc->label = name;
430 gc->owner = THIS_MODULE;
431 gc->parent = dev;
432 gc->get = gpio_mockup_get;
433 gc->set = gpio_mockup_set;
434 gc->get_multiple = gpio_mockup_get_multiple;
435 gc->set_multiple = gpio_mockup_set_multiple;
436 gc->direction_output = gpio_mockup_dirout;
437 gc->direction_input = gpio_mockup_dirin;
438 gc->get_direction = gpio_mockup_get_direction;
439 gc->set_config = gpio_mockup_set_config;
440 gc->to_irq = gpio_mockup_to_irq;
441 gc->free = gpio_mockup_free;
442
443 chip->lines = devm_kcalloc(dev, gc->ngpio,
444 sizeof(*chip->lines), GFP_KERNEL);
445 if (!chip->lines)
446 return -ENOMEM;
447
448 for (i = 0; i < gc->ngpio; i++)
449 chip->lines[i].dir = GPIO_LINE_DIRECTION_IN;
450
451 chip->irq_sim_domain = devm_irq_domain_create_sim(dev, NULL,
452 gc->ngpio);
453 if (IS_ERR(chip->irq_sim_domain))
454 return PTR_ERR(chip->irq_sim_domain);
455
456 rv = devm_add_action_or_reset(dev, gpio_mockup_dispose_mappings, chip);
457 if (rv)
458 return rv;
459
460 rv = devm_gpiochip_add_data(dev, &chip->gc, chip);
461 if (rv)
462 return rv;
463
464 gpio_mockup_debugfs_setup(dev, chip);
465
466 return devm_add_action_or_reset(dev, gpio_mockup_debugfs_cleanup, chip);
467}
468
469static const struct of_device_id gpio_mockup_of_match[] = {
470 { .compatible = "gpio-mockup", },
471 {},
472};
473MODULE_DEVICE_TABLE(of, gpio_mockup_of_match);
474
475static struct platform_driver gpio_mockup_driver = {
476 .driver = {
477 .name = "gpio-mockup",
478 .of_match_table = gpio_mockup_of_match,
479 },
480 .probe = gpio_mockup_probe,
481};
482
483static struct platform_device *gpio_mockup_pdevs[GPIO_MOCKUP_MAX_GC];
484
485static void gpio_mockup_unregister_pdevs(void)
486{
487 struct platform_device *pdev;
488 struct fwnode_handle *fwnode;
489 int i;
490
491 for (i = 0; i < GPIO_MOCKUP_MAX_GC; i++) {
492 pdev = gpio_mockup_pdevs[i];
493 if (!pdev)
494 continue;
495
496 fwnode = dev_fwnode(&pdev->dev);
497 platform_device_unregister(pdev);
498 fwnode_remove_software_node(fwnode);
499 }
500}
501
502static int __init gpio_mockup_register_chip(int idx)
503{
504 struct property_entry properties[GPIO_MOCKUP_MAX_PROP];
505 struct platform_device_info pdevinfo;
506 struct platform_device *pdev;
507 struct fwnode_handle *fwnode;
508 char **line_names = NULL;
509 char chip_label[32];
510 int prop = 0, base;
511 u16 ngpio;
512
513 memset(properties, 0, sizeof(properties));
514 memset(&pdevinfo, 0, sizeof(pdevinfo));
515
516 snprintf(chip_label, sizeof(chip_label), "gpio-mockup-%c", idx + 'A');
517 properties[prop++] = PROPERTY_ENTRY_STRING("chip-label", chip_label);
518
519 base = gpio_mockup_range_base(idx);
520 if (base >= 0)
521 properties[prop++] = PROPERTY_ENTRY_U32("gpio-base", base);
522
523 ngpio = base < 0 ? gpio_mockup_range_ngpio(idx)
524 : gpio_mockup_range_ngpio(idx) - base;
525 properties[prop++] = PROPERTY_ENTRY_U16("nr-gpios", ngpio);
526
527 if (gpio_mockup_named_lines) {
528 line_names = kasprintf_strarray(GFP_KERNEL, chip_label, ngpio);
529 if (!line_names)
530 return -ENOMEM;
531
532 properties[prop++] = PROPERTY_ENTRY_STRING_ARRAY_LEN(
533 "gpio-line-names", line_names, ngpio);
534 }
535
536 fwnode = fwnode_create_software_node(properties, NULL);
537 if (IS_ERR(fwnode)) {
538 kfree_strarray(line_names, ngpio);
539 return PTR_ERR(fwnode);
540 }
541
542 pdevinfo.name = "gpio-mockup";
543 pdevinfo.id = idx;
544 pdevinfo.fwnode = fwnode;
545
546 pdev = platform_device_register_full(&pdevinfo);
547 kfree_strarray(line_names, ngpio);
548 if (IS_ERR(pdev)) {
549 fwnode_remove_software_node(fwnode);
550 pr_err("error registering device");
551 return PTR_ERR(pdev);
552 }
553
554 gpio_mockup_pdevs[idx] = pdev;
555
556 return 0;
557}
558
559static int __init gpio_mockup_init(void)
560{
561 int i, num_chips, err;
562
563 if ((gpio_mockup_num_ranges % 2) ||
564 (gpio_mockup_num_ranges > GPIO_MOCKUP_MAX_RANGES))
565 return -EINVAL;
566
567 /* Each chip is described by two values. */
568 num_chips = gpio_mockup_num_ranges / 2;
569
570 /*
571 * The second value in the <base GPIO - number of GPIOS> pair must
572 * always be greater than 0.
573 */
574 for (i = 0; i < num_chips; i++) {
575 if (gpio_mockup_range_ngpio(i) < 0)
576 return -EINVAL;
577 }
578
579 gpio_mockup_dbg_dir = debugfs_create_dir("gpio-mockup", NULL);
580
581 err = platform_driver_register(&gpio_mockup_driver);
582 if (err) {
583 pr_err("error registering platform driver\n");
584 debugfs_remove_recursive(gpio_mockup_dbg_dir);
585 return err;
586 }
587
588 for (i = 0; i < num_chips; i++) {
589 err = gpio_mockup_register_chip(i);
590 if (err) {
591 platform_driver_unregister(&gpio_mockup_driver);
592 gpio_mockup_unregister_pdevs();
593 debugfs_remove_recursive(gpio_mockup_dbg_dir);
594 return err;
595 }
596 }
597
598 return 0;
599}
600
601static void __exit gpio_mockup_exit(void)
602{
603 gpio_mockup_unregister_pdevs();
604 debugfs_remove_recursive(gpio_mockup_dbg_dir);
605 platform_driver_unregister(&gpio_mockup_driver);
606}
607
608module_init(gpio_mockup_init);
609module_exit(gpio_mockup_exit);
610
611MODULE_AUTHOR("Kamlakant Patel <kamlakant.patel@broadcom.com>");
612MODULE_AUTHOR("Bamvor Jian Zhang <bamv2005@gmail.com>");
613MODULE_AUTHOR("Bartosz Golaszewski <brgl@bgdev.pl>");
614MODULE_DESCRIPTION("GPIO Testing driver");
615MODULE_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");