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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/slab.h>
23#include <linux/string_helpers.h>
24#include <linux/uaccess.h>
25
26#include "gpiolib.h"
27
28#define GPIO_MOCKUP_MAX_GC 10
29
30
31
32
33#define GPIO_MOCKUP_MAX_RANGES (GPIO_MOCKUP_MAX_GC * 2)
34
35#define GPIO_MOCKUP_MAX_PROP 5
36
37
38
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40
41
42struct gpio_mockup_line_status {
43 int dir;
44 int value;
45 int pull;
46};
47
48struct gpio_mockup_chip {
49 struct gpio_chip gc;
50 struct gpio_mockup_line_status *lines;
51 struct irq_domain *irq_sim_domain;
52 struct dentry *dbg_dir;
53 struct mutex lock;
54};
55
56struct gpio_mockup_dbgfs_private {
57 struct gpio_mockup_chip *chip;
58 struct gpio_desc *desc;
59 unsigned int offset;
60};
61
62static int gpio_mockup_ranges[GPIO_MOCKUP_MAX_RANGES];
63static int gpio_mockup_num_ranges;
64module_param_array(gpio_mockup_ranges, int, &gpio_mockup_num_ranges, 0400);
65
66static bool gpio_mockup_named_lines;
67module_param_named(gpio_mockup_named_lines,
68 gpio_mockup_named_lines, bool, 0400);
69
70static struct dentry *gpio_mockup_dbg_dir;
71
72static int gpio_mockup_range_base(unsigned int index)
73{
74 return gpio_mockup_ranges[index * 2];
75}
76
77static int gpio_mockup_range_ngpio(unsigned int index)
78{
79 return gpio_mockup_ranges[index * 2 + 1];
80}
81
82static int __gpio_mockup_get(struct gpio_mockup_chip *chip,
83 unsigned int offset)
84{
85 return chip->lines[offset].value;
86}
87
88static int gpio_mockup_get(struct gpio_chip *gc, unsigned int offset)
89{
90 struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
91 int val;
92
93 mutex_lock(&chip->lock);
94 val = __gpio_mockup_get(chip, offset);
95 mutex_unlock(&chip->lock);
96
97 return val;
98}
99
100static int gpio_mockup_get_multiple(struct gpio_chip *gc,
101 unsigned long *mask, unsigned long *bits)
102{
103 struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
104 unsigned int bit, val;
105
106 mutex_lock(&chip->lock);
107 for_each_set_bit(bit, mask, gc->ngpio) {
108 val = __gpio_mockup_get(chip, bit);
109 __assign_bit(bit, bits, val);
110 }
111 mutex_unlock(&chip->lock);
112
113 return 0;
114}
115
116static void __gpio_mockup_set(struct gpio_mockup_chip *chip,
117 unsigned int offset, int value)
118{
119 chip->lines[offset].value = !!value;
120}
121
122static void gpio_mockup_set(struct gpio_chip *gc,
123 unsigned int offset, int value)
124{
125 struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
126
127 mutex_lock(&chip->lock);
128 __gpio_mockup_set(chip, offset, value);
129 mutex_unlock(&chip->lock);
130}
131
132static void gpio_mockup_set_multiple(struct gpio_chip *gc,
133 unsigned long *mask, unsigned long *bits)
134{
135 struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
136 unsigned int bit;
137
138 mutex_lock(&chip->lock);
139 for_each_set_bit(bit, mask, gc->ngpio)
140 __gpio_mockup_set(chip, bit, test_bit(bit, bits));
141 mutex_unlock(&chip->lock);
142}
143
144static int gpio_mockup_apply_pull(struct gpio_mockup_chip *chip,
145 unsigned int offset, int value)
146{
147 int curr, irq, irq_type, ret = 0;
148 struct gpio_desc *desc;
149 struct gpio_chip *gc;
150
151 gc = &chip->gc;
152 desc = &gc->gpiodev->descs[offset];
153
154 mutex_lock(&chip->lock);
155
156 if (test_bit(FLAG_REQUESTED, &desc->flags) &&
157 !test_bit(FLAG_IS_OUT, &desc->flags)) {
158 curr = __gpio_mockup_get(chip, offset);
159 if (curr == value)
160 goto out;
161
162 irq = irq_find_mapping(chip->irq_sim_domain, offset);
163 if (!irq)
164
165
166
167
168
169
170 goto set_value;
171
172 irq_type = irq_get_trigger_type(irq);
173
174 if ((value == 1 && (irq_type & IRQ_TYPE_EDGE_RISING)) ||
175 (value == 0 && (irq_type & IRQ_TYPE_EDGE_FALLING))) {
176 ret = irq_set_irqchip_state(irq, IRQCHIP_STATE_PENDING,
177 true);
178 if (ret)
179 goto out;
180 }
181 }
182
183set_value:
184
185 if (!test_bit(FLAG_REQUESTED, &desc->flags) ||
186 !test_bit(FLAG_IS_OUT, &desc->flags))
187 __gpio_mockup_set(chip, offset, value);
188
189out:
190 chip->lines[offset].pull = value;
191 mutex_unlock(&chip->lock);
192 return ret;
193}
194
195static int gpio_mockup_set_config(struct gpio_chip *gc,
196 unsigned int offset, unsigned long config)
197{
198 struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
199
200 switch (pinconf_to_config_param(config)) {
201 case PIN_CONFIG_BIAS_PULL_UP:
202 return gpio_mockup_apply_pull(chip, offset, 1);
203 case PIN_CONFIG_BIAS_PULL_DOWN:
204 return gpio_mockup_apply_pull(chip, offset, 0);
205 default:
206 break;
207 }
208 return -ENOTSUPP;
209}
210
211static int gpio_mockup_dirout(struct gpio_chip *gc,
212 unsigned int offset, int value)
213{
214 struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
215
216 mutex_lock(&chip->lock);
217 chip->lines[offset].dir = GPIO_LINE_DIRECTION_OUT;
218 __gpio_mockup_set(chip, offset, value);
219 mutex_unlock(&chip->lock);
220
221 return 0;
222}
223
224static int gpio_mockup_dirin(struct gpio_chip *gc, unsigned int offset)
225{
226 struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
227
228 mutex_lock(&chip->lock);
229 chip->lines[offset].dir = GPIO_LINE_DIRECTION_IN;
230 mutex_unlock(&chip->lock);
231
232 return 0;
233}
234
235static int gpio_mockup_get_direction(struct gpio_chip *gc, unsigned int offset)
236{
237 struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
238 int direction;
239
240 mutex_lock(&chip->lock);
241 direction = chip->lines[offset].dir;
242 mutex_unlock(&chip->lock);
243
244 return direction;
245}
246
247static int gpio_mockup_to_irq(struct gpio_chip *gc, unsigned int offset)
248{
249 struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
250
251 return irq_create_mapping(chip->irq_sim_domain, offset);
252}
253
254static void gpio_mockup_free(struct gpio_chip *gc, unsigned int offset)
255{
256 struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
257
258 __gpio_mockup_set(chip, offset, chip->lines[offset].pull);
259}
260
261static ssize_t gpio_mockup_debugfs_read(struct file *file,
262 char __user *usr_buf,
263 size_t size, loff_t *ppos)
264{
265 struct gpio_mockup_dbgfs_private *priv;
266 struct gpio_mockup_chip *chip;
267 struct seq_file *sfile;
268 struct gpio_chip *gc;
269 int val, cnt;
270 char buf[3];
271
272 if (*ppos != 0)
273 return 0;
274
275 sfile = file->private_data;
276 priv = sfile->private;
277 chip = priv->chip;
278 gc = &chip->gc;
279
280 val = gpio_mockup_get(gc, priv->offset);
281 cnt = snprintf(buf, sizeof(buf), "%d\n", val);
282
283 return simple_read_from_buffer(usr_buf, size, ppos, buf, cnt);
284}
285
286static ssize_t gpio_mockup_debugfs_write(struct file *file,
287 const char __user *usr_buf,
288 size_t size, loff_t *ppos)
289{
290 struct gpio_mockup_dbgfs_private *priv;
291 int rv, val;
292 struct seq_file *sfile;
293
294 if (*ppos != 0)
295 return -EINVAL;
296
297 rv = kstrtoint_from_user(usr_buf, size, 0, &val);
298 if (rv)
299 return rv;
300 if (val != 0 && val != 1)
301 return -EINVAL;
302
303 sfile = file->private_data;
304 priv = sfile->private;
305 rv = gpio_mockup_apply_pull(priv->chip, priv->offset, val);
306 if (rv)
307 return rv;
308
309 return size;
310}
311
312static int gpio_mockup_debugfs_open(struct inode *inode, struct file *file)
313{
314 return single_open(file, NULL, inode->i_private);
315}
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338static const struct file_operations gpio_mockup_debugfs_ops = {
339 .owner = THIS_MODULE,
340 .open = gpio_mockup_debugfs_open,
341 .read = gpio_mockup_debugfs_read,
342 .write = gpio_mockup_debugfs_write,
343 .llseek = no_llseek,
344 .release = single_release,
345};
346
347static void gpio_mockup_debugfs_setup(struct device *dev,
348 struct gpio_mockup_chip *chip)
349{
350 struct gpio_mockup_dbgfs_private *priv;
351 struct gpio_chip *gc;
352 const char *devname;
353 char *name;
354 int i;
355
356 gc = &chip->gc;
357 devname = dev_name(&gc->gpiodev->dev);
358
359 chip->dbg_dir = debugfs_create_dir(devname, gpio_mockup_dbg_dir);
360
361 for (i = 0; i < gc->ngpio; i++) {
362 name = devm_kasprintf(dev, GFP_KERNEL, "%d", i);
363 if (!name)
364 return;
365
366 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
367 if (!priv)
368 return;
369
370 priv->chip = chip;
371 priv->offset = i;
372 priv->desc = &gc->gpiodev->descs[i];
373
374 debugfs_create_file(name, 0200, chip->dbg_dir, priv,
375 &gpio_mockup_debugfs_ops);
376 }
377}
378
379static void gpio_mockup_dispose_mappings(void *data)
380{
381 struct gpio_mockup_chip *chip = data;
382 struct gpio_chip *gc = &chip->gc;
383 int i, irq;
384
385 for (i = 0; i < gc->ngpio; i++) {
386 irq = irq_find_mapping(chip->irq_sim_domain, i);
387 if (irq)
388 irq_dispose_mapping(irq);
389 }
390}
391
392static int gpio_mockup_probe(struct platform_device *pdev)
393{
394 struct gpio_mockup_chip *chip;
395 struct gpio_chip *gc;
396 struct device *dev;
397 const char *name;
398 int rv, base, i;
399 u16 ngpio;
400
401 dev = &pdev->dev;
402
403 rv = device_property_read_u32(dev, "gpio-base", &base);
404 if (rv)
405 base = -1;
406
407 rv = device_property_read_u16(dev, "nr-gpios", &ngpio);
408 if (rv)
409 return rv;
410
411 rv = device_property_read_string(dev, "chip-label", &name);
412 if (rv)
413 name = dev_name(dev);
414
415 chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
416 if (!chip)
417 return -ENOMEM;
418
419 mutex_init(&chip->lock);
420
421 gc = &chip->gc;
422 gc->base = base;
423 gc->ngpio = ngpio;
424 gc->label = name;
425 gc->owner = THIS_MODULE;
426 gc->parent = dev;
427 gc->get = gpio_mockup_get;
428 gc->set = gpio_mockup_set;
429 gc->get_multiple = gpio_mockup_get_multiple;
430 gc->set_multiple = gpio_mockup_set_multiple;
431 gc->direction_output = gpio_mockup_dirout;
432 gc->direction_input = gpio_mockup_dirin;
433 gc->get_direction = gpio_mockup_get_direction;
434 gc->set_config = gpio_mockup_set_config;
435 gc->to_irq = gpio_mockup_to_irq;
436 gc->free = gpio_mockup_free;
437
438 chip->lines = devm_kcalloc(dev, gc->ngpio,
439 sizeof(*chip->lines), GFP_KERNEL);
440 if (!chip->lines)
441 return -ENOMEM;
442
443 for (i = 0; i < gc->ngpio; i++)
444 chip->lines[i].dir = GPIO_LINE_DIRECTION_IN;
445
446 chip->irq_sim_domain = devm_irq_domain_create_sim(dev, NULL,
447 gc->ngpio);
448 if (IS_ERR(chip->irq_sim_domain))
449 return PTR_ERR(chip->irq_sim_domain);
450
451 rv = devm_add_action_or_reset(dev, gpio_mockup_dispose_mappings, chip);
452 if (rv)
453 return rv;
454
455 rv = devm_gpiochip_add_data(dev, &chip->gc, chip);
456 if (rv)
457 return rv;
458
459 gpio_mockup_debugfs_setup(dev, chip);
460
461 return 0;
462}
463
464static const struct of_device_id gpio_mockup_of_match[] = {
465 { .compatible = "gpio-mockup", },
466 {},
467};
468MODULE_DEVICE_TABLE(of, gpio_mockup_of_match);
469
470static struct platform_driver gpio_mockup_driver = {
471 .driver = {
472 .name = "gpio-mockup",
473 .of_match_table = gpio_mockup_of_match,
474 },
475 .probe = gpio_mockup_probe,
476};
477
478static struct platform_device *gpio_mockup_pdevs[GPIO_MOCKUP_MAX_GC];
479
480static void gpio_mockup_unregister_pdevs(void)
481{
482 struct platform_device *pdev;
483 int i;
484
485 for (i = 0; i < GPIO_MOCKUP_MAX_GC; i++) {
486 pdev = gpio_mockup_pdevs[i];
487
488 if (pdev)
489 platform_device_unregister(pdev);
490 }
491}
492
493static __init char **gpio_mockup_make_line_names(const char *label,
494 unsigned int num_lines)
495{
496 unsigned int i;
497 char **names;
498
499 names = kcalloc(num_lines + 1, sizeof(char *), GFP_KERNEL);
500 if (!names)
501 return NULL;
502
503 for (i = 0; i < num_lines; i++) {
504 names[i] = kasprintf(GFP_KERNEL, "%s-%u", label, i);
505 if (!names[i]) {
506 kfree_strarray(names, i);
507 return NULL;
508 }
509 }
510
511 return names;
512}
513
514static int __init gpio_mockup_register_chip(int idx)
515{
516 struct property_entry properties[GPIO_MOCKUP_MAX_PROP];
517 struct platform_device_info pdevinfo;
518 struct platform_device *pdev;
519 char **line_names = NULL;
520 char chip_label[32];
521 int prop = 0, base;
522 u16 ngpio;
523
524 memset(properties, 0, sizeof(properties));
525 memset(&pdevinfo, 0, sizeof(pdevinfo));
526
527 snprintf(chip_label, sizeof(chip_label), "gpio-mockup-%c", idx + 'A');
528 properties[prop++] = PROPERTY_ENTRY_STRING("chip-label", chip_label);
529
530 base = gpio_mockup_range_base(idx);
531 if (base >= 0)
532 properties[prop++] = PROPERTY_ENTRY_U32("gpio-base", base);
533
534 ngpio = base < 0 ? gpio_mockup_range_ngpio(idx)
535 : gpio_mockup_range_ngpio(idx) - base;
536 properties[prop++] = PROPERTY_ENTRY_U16("nr-gpios", ngpio);
537
538 if (gpio_mockup_named_lines) {
539 line_names = gpio_mockup_make_line_names(chip_label, ngpio);
540 if (!line_names)
541 return -ENOMEM;
542
543 properties[prop++] = PROPERTY_ENTRY_STRING_ARRAY_LEN(
544 "gpio-line-names", line_names, ngpio);
545 }
546
547 pdevinfo.name = "gpio-mockup";
548 pdevinfo.id = idx;
549 pdevinfo.properties = properties;
550
551 pdev = platform_device_register_full(&pdevinfo);
552 kfree_strarray(line_names, ngpio);
553 if (IS_ERR(pdev)) {
554 pr_err("error registering device");
555 return PTR_ERR(pdev);
556 }
557
558 gpio_mockup_pdevs[idx] = pdev;
559
560 return 0;
561}
562
563static int __init gpio_mockup_init(void)
564{
565 int i, num_chips, err;
566
567 if ((gpio_mockup_num_ranges % 2) ||
568 (gpio_mockup_num_ranges > GPIO_MOCKUP_MAX_RANGES))
569 return -EINVAL;
570
571
572 num_chips = gpio_mockup_num_ranges / 2;
573
574
575
576
577
578 for (i = 0; i < num_chips; i++) {
579 if (gpio_mockup_range_ngpio(i) < 0)
580 return -EINVAL;
581 }
582
583 gpio_mockup_dbg_dir = debugfs_create_dir("gpio-mockup", NULL);
584
585 err = platform_driver_register(&gpio_mockup_driver);
586 if (err) {
587 pr_err("error registering platform driver\n");
588 debugfs_remove_recursive(gpio_mockup_dbg_dir);
589 return err;
590 }
591
592 for (i = 0; i < num_chips; i++) {
593 err = gpio_mockup_register_chip(i);
594 if (err) {
595 platform_driver_unregister(&gpio_mockup_driver);
596 gpio_mockup_unregister_pdevs();
597 debugfs_remove_recursive(gpio_mockup_dbg_dir);
598 return err;
599 }
600 }
601
602 return 0;
603}
604
605static void __exit gpio_mockup_exit(void)
606{
607 debugfs_remove_recursive(gpio_mockup_dbg_dir);
608 platform_driver_unregister(&gpio_mockup_driver);
609 gpio_mockup_unregister_pdevs();
610}
611
612module_init(gpio_mockup_init);
613module_exit(gpio_mockup_exit);
614
615MODULE_AUTHOR("Kamlakant Patel <kamlakant.patel@broadcom.com>");
616MODULE_AUTHOR("Bamvor Jian Zhang <bamv2005@gmail.com>");
617MODULE_AUTHOR("Bartosz Golaszewski <brgl@bgdev.pl>");
618MODULE_DESCRIPTION("GPIO Testing driver");
619MODULE_LICENSE("GPL v2");
620