Loading...
1// SPDX-License-Identifier: GPL-2.0-only
2//
3// GPIO Aggregator
4//
5// Copyright (C) 2019-2020 Glider bv
6
7#define DRV_NAME "gpio-aggregator"
8#define pr_fmt(fmt) DRV_NAME ": " fmt
9
10#include <linux/bitmap.h>
11#include <linux/bitops.h>
12#include <linux/ctype.h>
13#include <linux/gpio.h>
14#include <linux/gpio/consumer.h>
15#include <linux/gpio/driver.h>
16#include <linux/gpio/machine.h>
17#include <linux/idr.h>
18#include <linux/kernel.h>
19#include <linux/module.h>
20#include <linux/mutex.h>
21#include <linux/overflow.h>
22#include <linux/platform_device.h>
23#include <linux/spinlock.h>
24#include <linux/string.h>
25
26
27/*
28 * GPIO Aggregator sysfs interface
29 */
30
31struct gpio_aggregator {
32 struct gpiod_lookup_table *lookups;
33 struct platform_device *pdev;
34 char args[];
35};
36
37static DEFINE_MUTEX(gpio_aggregator_lock); /* protects idr */
38static DEFINE_IDR(gpio_aggregator_idr);
39
40static char *get_arg(char **args)
41{
42 char *start, *end;
43
44 start = skip_spaces(*args);
45 if (!*start)
46 return NULL;
47
48 if (*start == '"') {
49 /* Quoted arg */
50 end = strchr(++start, '"');
51 if (!end)
52 return ERR_PTR(-EINVAL);
53 } else {
54 /* Unquoted arg */
55 for (end = start; *end && !isspace(*end); end++) ;
56 }
57
58 if (*end)
59 *end++ = '\0';
60
61 *args = end;
62 return start;
63}
64
65static bool isrange(const char *s)
66{
67 size_t n;
68
69 if (IS_ERR_OR_NULL(s))
70 return false;
71
72 while (1) {
73 n = strspn(s, "0123456789");
74 if (!n)
75 return false;
76
77 s += n;
78
79 switch (*s++) {
80 case '\0':
81 return true;
82
83 case '-':
84 case ',':
85 break;
86
87 default:
88 return false;
89 }
90 }
91}
92
93static int aggr_add_gpio(struct gpio_aggregator *aggr, const char *key,
94 int hwnum, unsigned int *n)
95{
96 struct gpiod_lookup_table *lookups;
97
98 lookups = krealloc(aggr->lookups, struct_size(lookups, table, *n + 2),
99 GFP_KERNEL);
100 if (!lookups)
101 return -ENOMEM;
102
103 lookups->table[*n] =
104 (struct gpiod_lookup)GPIO_LOOKUP_IDX(key, hwnum, NULL, *n, 0);
105
106 (*n)++;
107 memset(&lookups->table[*n], 0, sizeof(lookups->table[*n]));
108
109 aggr->lookups = lookups;
110 return 0;
111}
112
113static int aggr_parse(struct gpio_aggregator *aggr)
114{
115 char *args = aggr->args;
116 unsigned long *bitmap;
117 unsigned int i, n = 0;
118 char *name, *offsets;
119 int error = 0;
120
121 bitmap = bitmap_alloc(ARCH_NR_GPIOS, GFP_KERNEL);
122 if (!bitmap)
123 return -ENOMEM;
124
125 for (name = get_arg(&args), offsets = get_arg(&args); name;
126 offsets = get_arg(&args)) {
127 if (IS_ERR(name)) {
128 pr_err("Cannot get GPIO specifier: %pe\n", name);
129 error = PTR_ERR(name);
130 goto free_bitmap;
131 }
132
133 if (!isrange(offsets)) {
134 /* Named GPIO line */
135 error = aggr_add_gpio(aggr, name, U16_MAX, &n);
136 if (error)
137 goto free_bitmap;
138
139 name = offsets;
140 continue;
141 }
142
143 /* GPIO chip + offset(s) */
144 error = bitmap_parselist(offsets, bitmap, ARCH_NR_GPIOS);
145 if (error) {
146 pr_err("Cannot parse %s: %d\n", offsets, error);
147 goto free_bitmap;
148 }
149
150 for_each_set_bit(i, bitmap, ARCH_NR_GPIOS) {
151 error = aggr_add_gpio(aggr, name, i, &n);
152 if (error)
153 goto free_bitmap;
154 }
155
156 name = get_arg(&args);
157 }
158
159 if (!n) {
160 pr_err("No GPIOs specified\n");
161 error = -EINVAL;
162 }
163
164free_bitmap:
165 bitmap_free(bitmap);
166 return error;
167}
168
169static ssize_t new_device_store(struct device_driver *driver, const char *buf,
170 size_t count)
171{
172 struct gpio_aggregator *aggr;
173 struct platform_device *pdev;
174 int res, id;
175
176 /* kernfs guarantees string termination, so count + 1 is safe */
177 aggr = kzalloc(sizeof(*aggr) + count + 1, GFP_KERNEL);
178 if (!aggr)
179 return -ENOMEM;
180
181 memcpy(aggr->args, buf, count + 1);
182
183 aggr->lookups = kzalloc(struct_size(aggr->lookups, table, 1),
184 GFP_KERNEL);
185 if (!aggr->lookups) {
186 res = -ENOMEM;
187 goto free_ga;
188 }
189
190 mutex_lock(&gpio_aggregator_lock);
191 id = idr_alloc(&gpio_aggregator_idr, aggr, 0, 0, GFP_KERNEL);
192 mutex_unlock(&gpio_aggregator_lock);
193
194 if (id < 0) {
195 res = id;
196 goto free_table;
197 }
198
199 aggr->lookups->dev_id = kasprintf(GFP_KERNEL, "%s.%d", DRV_NAME, id);
200 if (!aggr->lookups->dev_id) {
201 res = -ENOMEM;
202 goto remove_idr;
203 }
204
205 res = aggr_parse(aggr);
206 if (res)
207 goto free_dev_id;
208
209 gpiod_add_lookup_table(aggr->lookups);
210
211 pdev = platform_device_register_simple(DRV_NAME, id, NULL, 0);
212 if (IS_ERR(pdev)) {
213 res = PTR_ERR(pdev);
214 goto remove_table;
215 }
216
217 aggr->pdev = pdev;
218 return count;
219
220remove_table:
221 gpiod_remove_lookup_table(aggr->lookups);
222free_dev_id:
223 kfree(aggr->lookups->dev_id);
224remove_idr:
225 mutex_lock(&gpio_aggregator_lock);
226 idr_remove(&gpio_aggregator_idr, id);
227 mutex_unlock(&gpio_aggregator_lock);
228free_table:
229 kfree(aggr->lookups);
230free_ga:
231 kfree(aggr);
232 return res;
233}
234
235static DRIVER_ATTR_WO(new_device);
236
237static void gpio_aggregator_free(struct gpio_aggregator *aggr)
238{
239 platform_device_unregister(aggr->pdev);
240 gpiod_remove_lookup_table(aggr->lookups);
241 kfree(aggr->lookups->dev_id);
242 kfree(aggr->lookups);
243 kfree(aggr);
244}
245
246static ssize_t delete_device_store(struct device_driver *driver,
247 const char *buf, size_t count)
248{
249 struct gpio_aggregator *aggr;
250 unsigned int id;
251 int error;
252
253 if (!str_has_prefix(buf, DRV_NAME "."))
254 return -EINVAL;
255
256 error = kstrtouint(buf + strlen(DRV_NAME "."), 10, &id);
257 if (error)
258 return error;
259
260 mutex_lock(&gpio_aggregator_lock);
261 aggr = idr_remove(&gpio_aggregator_idr, id);
262 mutex_unlock(&gpio_aggregator_lock);
263 if (!aggr)
264 return -ENOENT;
265
266 gpio_aggregator_free(aggr);
267 return count;
268}
269static DRIVER_ATTR_WO(delete_device);
270
271static struct attribute *gpio_aggregator_attrs[] = {
272 &driver_attr_new_device.attr,
273 &driver_attr_delete_device.attr,
274 NULL,
275};
276ATTRIBUTE_GROUPS(gpio_aggregator);
277
278static int __exit gpio_aggregator_idr_remove(int id, void *p, void *data)
279{
280 gpio_aggregator_free(p);
281 return 0;
282}
283
284static void __exit gpio_aggregator_remove_all(void)
285{
286 mutex_lock(&gpio_aggregator_lock);
287 idr_for_each(&gpio_aggregator_idr, gpio_aggregator_idr_remove, NULL);
288 idr_destroy(&gpio_aggregator_idr);
289 mutex_unlock(&gpio_aggregator_lock);
290}
291
292
293/*
294 * GPIO Forwarder
295 */
296
297struct gpiochip_fwd {
298 struct gpio_chip chip;
299 struct gpio_desc **descs;
300 union {
301 struct mutex mlock; /* protects tmp[] if can_sleep */
302 spinlock_t slock; /* protects tmp[] if !can_sleep */
303 };
304 unsigned long tmp[]; /* values and descs for multiple ops */
305};
306
307static int gpio_fwd_get_direction(struct gpio_chip *chip, unsigned int offset)
308{
309 struct gpiochip_fwd *fwd = gpiochip_get_data(chip);
310
311 return gpiod_get_direction(fwd->descs[offset]);
312}
313
314static int gpio_fwd_direction_input(struct gpio_chip *chip, unsigned int offset)
315{
316 struct gpiochip_fwd *fwd = gpiochip_get_data(chip);
317
318 return gpiod_direction_input(fwd->descs[offset]);
319}
320
321static int gpio_fwd_direction_output(struct gpio_chip *chip,
322 unsigned int offset, int value)
323{
324 struct gpiochip_fwd *fwd = gpiochip_get_data(chip);
325
326 return gpiod_direction_output(fwd->descs[offset], value);
327}
328
329static int gpio_fwd_get(struct gpio_chip *chip, unsigned int offset)
330{
331 struct gpiochip_fwd *fwd = gpiochip_get_data(chip);
332
333 return gpiod_get_value(fwd->descs[offset]);
334}
335
336static int gpio_fwd_get_multiple(struct gpio_chip *chip, unsigned long *mask,
337 unsigned long *bits)
338{
339 struct gpiochip_fwd *fwd = gpiochip_get_data(chip);
340 unsigned long *values, flags = 0;
341 struct gpio_desc **descs;
342 unsigned int i, j = 0;
343 int error;
344
345 if (chip->can_sleep)
346 mutex_lock(&fwd->mlock);
347 else
348 spin_lock_irqsave(&fwd->slock, flags);
349
350 /* Both values bitmap and desc pointers are stored in tmp[] */
351 values = &fwd->tmp[0];
352 descs = (void *)&fwd->tmp[BITS_TO_LONGS(fwd->chip.ngpio)];
353
354 bitmap_clear(values, 0, fwd->chip.ngpio);
355 for_each_set_bit(i, mask, fwd->chip.ngpio)
356 descs[j++] = fwd->descs[i];
357
358 error = gpiod_get_array_value(j, descs, NULL, values);
359 if (!error) {
360 j = 0;
361 for_each_set_bit(i, mask, fwd->chip.ngpio)
362 __assign_bit(i, bits, test_bit(j++, values));
363 }
364
365 if (chip->can_sleep)
366 mutex_unlock(&fwd->mlock);
367 else
368 spin_unlock_irqrestore(&fwd->slock, flags);
369
370 return error;
371}
372
373static void gpio_fwd_set(struct gpio_chip *chip, unsigned int offset, int value)
374{
375 struct gpiochip_fwd *fwd = gpiochip_get_data(chip);
376
377 gpiod_set_value(fwd->descs[offset], value);
378}
379
380static void gpio_fwd_set_multiple(struct gpio_chip *chip, unsigned long *mask,
381 unsigned long *bits)
382{
383 struct gpiochip_fwd *fwd = gpiochip_get_data(chip);
384 unsigned long *values, flags = 0;
385 struct gpio_desc **descs;
386 unsigned int i, j = 0;
387
388 if (chip->can_sleep)
389 mutex_lock(&fwd->mlock);
390 else
391 spin_lock_irqsave(&fwd->slock, flags);
392
393 /* Both values bitmap and desc pointers are stored in tmp[] */
394 values = &fwd->tmp[0];
395 descs = (void *)&fwd->tmp[BITS_TO_LONGS(fwd->chip.ngpio)];
396
397 for_each_set_bit(i, mask, fwd->chip.ngpio) {
398 __assign_bit(j, values, test_bit(i, bits));
399 descs[j++] = fwd->descs[i];
400 }
401
402 gpiod_set_array_value(j, descs, NULL, values);
403
404 if (chip->can_sleep)
405 mutex_unlock(&fwd->mlock);
406 else
407 spin_unlock_irqrestore(&fwd->slock, flags);
408}
409
410static int gpio_fwd_set_config(struct gpio_chip *chip, unsigned int offset,
411 unsigned long config)
412{
413 struct gpiochip_fwd *fwd = gpiochip_get_data(chip);
414
415 return gpiod_set_config(fwd->descs[offset], config);
416}
417
418/**
419 * gpiochip_fwd_create() - Create a new GPIO forwarder
420 * @dev: Parent device pointer
421 * @ngpios: Number of GPIOs in the forwarder.
422 * @descs: Array containing the GPIO descriptors to forward to.
423 * This array must contain @ngpios entries, and must not be deallocated
424 * before the forwarder has been destroyed again.
425 *
426 * This function creates a new gpiochip, which forwards all GPIO operations to
427 * the passed GPIO descriptors.
428 *
429 * Return: An opaque object pointer, or an ERR_PTR()-encoded negative error
430 * code on failure.
431 */
432static struct gpiochip_fwd *gpiochip_fwd_create(struct device *dev,
433 unsigned int ngpios,
434 struct gpio_desc *descs[])
435{
436 const char *label = dev_name(dev);
437 struct gpiochip_fwd *fwd;
438 struct gpio_chip *chip;
439 unsigned int i;
440 int error;
441
442 fwd = devm_kzalloc(dev, struct_size(fwd, tmp,
443 BITS_TO_LONGS(ngpios) + ngpios), GFP_KERNEL);
444 if (!fwd)
445 return ERR_PTR(-ENOMEM);
446
447 chip = &fwd->chip;
448
449 /*
450 * If any of the GPIO lines are sleeping, then the entire forwarder
451 * will be sleeping.
452 * If any of the chips support .set_config(), then the forwarder will
453 * support setting configs.
454 */
455 for (i = 0; i < ngpios; i++) {
456 struct gpio_chip *parent = gpiod_to_chip(descs[i]);
457
458 dev_dbg(dev, "%u => gpio-%d\n", i, desc_to_gpio(descs[i]));
459
460 if (gpiod_cansleep(descs[i]))
461 chip->can_sleep = true;
462 if (parent && parent->set_config)
463 chip->set_config = gpio_fwd_set_config;
464 }
465
466 chip->label = label;
467 chip->parent = dev;
468 chip->owner = THIS_MODULE;
469 chip->get_direction = gpio_fwd_get_direction;
470 chip->direction_input = gpio_fwd_direction_input;
471 chip->direction_output = gpio_fwd_direction_output;
472 chip->get = gpio_fwd_get;
473 chip->get_multiple = gpio_fwd_get_multiple;
474 chip->set = gpio_fwd_set;
475 chip->set_multiple = gpio_fwd_set_multiple;
476 chip->base = -1;
477 chip->ngpio = ngpios;
478 fwd->descs = descs;
479
480 if (chip->can_sleep)
481 mutex_init(&fwd->mlock);
482 else
483 spin_lock_init(&fwd->slock);
484
485 error = devm_gpiochip_add_data(dev, chip, fwd);
486 if (error)
487 return ERR_PTR(error);
488
489 return fwd;
490}
491
492
493/*
494 * GPIO Aggregator platform device
495 */
496
497static int gpio_aggregator_probe(struct platform_device *pdev)
498{
499 struct device *dev = &pdev->dev;
500 struct gpio_desc **descs;
501 struct gpiochip_fwd *fwd;
502 int i, n;
503
504 n = gpiod_count(dev, NULL);
505 if (n < 0)
506 return n;
507
508 descs = devm_kmalloc_array(dev, n, sizeof(*descs), GFP_KERNEL);
509 if (!descs)
510 return -ENOMEM;
511
512 for (i = 0; i < n; i++) {
513 descs[i] = devm_gpiod_get_index(dev, NULL, i, GPIOD_ASIS);
514 if (IS_ERR(descs[i]))
515 return PTR_ERR(descs[i]);
516 }
517
518 fwd = gpiochip_fwd_create(dev, n, descs);
519 if (IS_ERR(fwd))
520 return PTR_ERR(fwd);
521
522 platform_set_drvdata(pdev, fwd);
523 return 0;
524}
525
526#ifdef CONFIG_OF
527static const struct of_device_id gpio_aggregator_dt_ids[] = {
528 /*
529 * Add GPIO-operated devices controlled from userspace below,
530 * or use "driver_override" in sysfs
531 */
532 {},
533};
534MODULE_DEVICE_TABLE(of, gpio_aggregator_dt_ids);
535#endif
536
537static struct platform_driver gpio_aggregator_driver = {
538 .probe = gpio_aggregator_probe,
539 .driver = {
540 .name = DRV_NAME,
541 .groups = gpio_aggregator_groups,
542 .of_match_table = of_match_ptr(gpio_aggregator_dt_ids),
543 },
544};
545
546static int __init gpio_aggregator_init(void)
547{
548 return platform_driver_register(&gpio_aggregator_driver);
549}
550module_init(gpio_aggregator_init);
551
552static void __exit gpio_aggregator_exit(void)
553{
554 gpio_aggregator_remove_all();
555 platform_driver_unregister(&gpio_aggregator_driver);
556}
557module_exit(gpio_aggregator_exit);
558
559MODULE_AUTHOR("Geert Uytterhoeven <geert+renesas@glider.be>");
560MODULE_DESCRIPTION("GPIO Aggregator");
561MODULE_LICENSE("GPL v2");
1// SPDX-License-Identifier: GPL-2.0-only
2//
3// GPIO Aggregator
4//
5// Copyright (C) 2019-2020 Glider bv
6
7#define DRV_NAME "gpio-aggregator"
8#define pr_fmt(fmt) DRV_NAME ": " fmt
9
10#include <linux/bitmap.h>
11#include <linux/bitops.h>
12#include <linux/ctype.h>
13#include <linux/gpio.h>
14#include <linux/gpio/consumer.h>
15#include <linux/gpio/driver.h>
16#include <linux/gpio/machine.h>
17#include <linux/idr.h>
18#include <linux/kernel.h>
19#include <linux/module.h>
20#include <linux/mutex.h>
21#include <linux/overflow.h>
22#include <linux/platform_device.h>
23#include <linux/spinlock.h>
24#include <linux/string.h>
25
26
27/*
28 * GPIO Aggregator sysfs interface
29 */
30
31struct gpio_aggregator {
32 struct gpiod_lookup_table *lookups;
33 struct platform_device *pdev;
34 char args[];
35};
36
37static DEFINE_MUTEX(gpio_aggregator_lock); /* protects idr */
38static DEFINE_IDR(gpio_aggregator_idr);
39
40static int aggr_add_gpio(struct gpio_aggregator *aggr, const char *key,
41 int hwnum, unsigned int *n)
42{
43 struct gpiod_lookup_table *lookups;
44
45 lookups = krealloc(aggr->lookups, struct_size(lookups, table, *n + 2),
46 GFP_KERNEL);
47 if (!lookups)
48 return -ENOMEM;
49
50 lookups->table[*n] = GPIO_LOOKUP_IDX(key, hwnum, NULL, *n, 0);
51
52 (*n)++;
53 memset(&lookups->table[*n], 0, sizeof(lookups->table[*n]));
54
55 aggr->lookups = lookups;
56 return 0;
57}
58
59static int aggr_parse(struct gpio_aggregator *aggr)
60{
61 char *args = skip_spaces(aggr->args);
62 char *name, *offsets, *p;
63 unsigned long *bitmap;
64 unsigned int i, n = 0;
65 int error = 0;
66
67 bitmap = bitmap_alloc(ARCH_NR_GPIOS, GFP_KERNEL);
68 if (!bitmap)
69 return -ENOMEM;
70
71 args = next_arg(args, &name, &p);
72 while (*args) {
73 args = next_arg(args, &offsets, &p);
74
75 p = get_options(offsets, 0, &error);
76 if (error == 0 || *p) {
77 /* Named GPIO line */
78 error = aggr_add_gpio(aggr, name, U16_MAX, &n);
79 if (error)
80 goto free_bitmap;
81
82 name = offsets;
83 continue;
84 }
85
86 /* GPIO chip + offset(s) */
87 error = bitmap_parselist(offsets, bitmap, ARCH_NR_GPIOS);
88 if (error) {
89 pr_err("Cannot parse %s: %d\n", offsets, error);
90 goto free_bitmap;
91 }
92
93 for_each_set_bit(i, bitmap, ARCH_NR_GPIOS) {
94 error = aggr_add_gpio(aggr, name, i, &n);
95 if (error)
96 goto free_bitmap;
97 }
98
99 args = next_arg(args, &name, &p);
100 }
101
102 if (!n) {
103 pr_err("No GPIOs specified\n");
104 error = -EINVAL;
105 }
106
107free_bitmap:
108 bitmap_free(bitmap);
109 return error;
110}
111
112static ssize_t new_device_store(struct device_driver *driver, const char *buf,
113 size_t count)
114{
115 struct gpio_aggregator *aggr;
116 struct platform_device *pdev;
117 int res, id;
118
119 /* kernfs guarantees string termination, so count + 1 is safe */
120 aggr = kzalloc(sizeof(*aggr) + count + 1, GFP_KERNEL);
121 if (!aggr)
122 return -ENOMEM;
123
124 memcpy(aggr->args, buf, count + 1);
125
126 aggr->lookups = kzalloc(struct_size(aggr->lookups, table, 1),
127 GFP_KERNEL);
128 if (!aggr->lookups) {
129 res = -ENOMEM;
130 goto free_ga;
131 }
132
133 mutex_lock(&gpio_aggregator_lock);
134 id = idr_alloc(&gpio_aggregator_idr, aggr, 0, 0, GFP_KERNEL);
135 mutex_unlock(&gpio_aggregator_lock);
136
137 if (id < 0) {
138 res = id;
139 goto free_table;
140 }
141
142 aggr->lookups->dev_id = kasprintf(GFP_KERNEL, "%s.%d", DRV_NAME, id);
143 if (!aggr->lookups->dev_id) {
144 res = -ENOMEM;
145 goto remove_idr;
146 }
147
148 res = aggr_parse(aggr);
149 if (res)
150 goto free_dev_id;
151
152 gpiod_add_lookup_table(aggr->lookups);
153
154 pdev = platform_device_register_simple(DRV_NAME, id, NULL, 0);
155 if (IS_ERR(pdev)) {
156 res = PTR_ERR(pdev);
157 goto remove_table;
158 }
159
160 aggr->pdev = pdev;
161 return count;
162
163remove_table:
164 gpiod_remove_lookup_table(aggr->lookups);
165free_dev_id:
166 kfree(aggr->lookups->dev_id);
167remove_idr:
168 mutex_lock(&gpio_aggregator_lock);
169 idr_remove(&gpio_aggregator_idr, id);
170 mutex_unlock(&gpio_aggregator_lock);
171free_table:
172 kfree(aggr->lookups);
173free_ga:
174 kfree(aggr);
175 return res;
176}
177
178static DRIVER_ATTR_WO(new_device);
179
180static void gpio_aggregator_free(struct gpio_aggregator *aggr)
181{
182 platform_device_unregister(aggr->pdev);
183 gpiod_remove_lookup_table(aggr->lookups);
184 kfree(aggr->lookups->dev_id);
185 kfree(aggr->lookups);
186 kfree(aggr);
187}
188
189static ssize_t delete_device_store(struct device_driver *driver,
190 const char *buf, size_t count)
191{
192 struct gpio_aggregator *aggr;
193 unsigned int id;
194 int error;
195
196 if (!str_has_prefix(buf, DRV_NAME "."))
197 return -EINVAL;
198
199 error = kstrtouint(buf + strlen(DRV_NAME "."), 10, &id);
200 if (error)
201 return error;
202
203 mutex_lock(&gpio_aggregator_lock);
204 aggr = idr_remove(&gpio_aggregator_idr, id);
205 mutex_unlock(&gpio_aggregator_lock);
206 if (!aggr)
207 return -ENOENT;
208
209 gpio_aggregator_free(aggr);
210 return count;
211}
212static DRIVER_ATTR_WO(delete_device);
213
214static struct attribute *gpio_aggregator_attrs[] = {
215 &driver_attr_new_device.attr,
216 &driver_attr_delete_device.attr,
217 NULL
218};
219ATTRIBUTE_GROUPS(gpio_aggregator);
220
221static int __exit gpio_aggregator_idr_remove(int id, void *p, void *data)
222{
223 gpio_aggregator_free(p);
224 return 0;
225}
226
227static void __exit gpio_aggregator_remove_all(void)
228{
229 mutex_lock(&gpio_aggregator_lock);
230 idr_for_each(&gpio_aggregator_idr, gpio_aggregator_idr_remove, NULL);
231 idr_destroy(&gpio_aggregator_idr);
232 mutex_unlock(&gpio_aggregator_lock);
233}
234
235
236/*
237 * GPIO Forwarder
238 */
239
240struct gpiochip_fwd {
241 struct gpio_chip chip;
242 struct gpio_desc **descs;
243 union {
244 struct mutex mlock; /* protects tmp[] if can_sleep */
245 spinlock_t slock; /* protects tmp[] if !can_sleep */
246 };
247 unsigned long tmp[]; /* values and descs for multiple ops */
248};
249
250static int gpio_fwd_get_direction(struct gpio_chip *chip, unsigned int offset)
251{
252 struct gpiochip_fwd *fwd = gpiochip_get_data(chip);
253
254 return gpiod_get_direction(fwd->descs[offset]);
255}
256
257static int gpio_fwd_direction_input(struct gpio_chip *chip, unsigned int offset)
258{
259 struct gpiochip_fwd *fwd = gpiochip_get_data(chip);
260
261 return gpiod_direction_input(fwd->descs[offset]);
262}
263
264static int gpio_fwd_direction_output(struct gpio_chip *chip,
265 unsigned int offset, int value)
266{
267 struct gpiochip_fwd *fwd = gpiochip_get_data(chip);
268
269 return gpiod_direction_output(fwd->descs[offset], value);
270}
271
272static int gpio_fwd_get(struct gpio_chip *chip, unsigned int offset)
273{
274 struct gpiochip_fwd *fwd = gpiochip_get_data(chip);
275
276 return gpiod_get_value(fwd->descs[offset]);
277}
278
279static int gpio_fwd_get_multiple(struct gpiochip_fwd *fwd, unsigned long *mask,
280 unsigned long *bits)
281{
282 struct gpio_desc **descs;
283 unsigned long *values;
284 unsigned int i, j = 0;
285 int error;
286
287 /* Both values bitmap and desc pointers are stored in tmp[] */
288 values = &fwd->tmp[0];
289 descs = (void *)&fwd->tmp[BITS_TO_LONGS(fwd->chip.ngpio)];
290
291 bitmap_clear(values, 0, fwd->chip.ngpio);
292 for_each_set_bit(i, mask, fwd->chip.ngpio)
293 descs[j++] = fwd->descs[i];
294
295 error = gpiod_get_array_value(j, descs, NULL, values);
296 if (error)
297 return error;
298
299 j = 0;
300 for_each_set_bit(i, mask, fwd->chip.ngpio)
301 __assign_bit(i, bits, test_bit(j++, values));
302
303 return 0;
304}
305
306static int gpio_fwd_get_multiple_locked(struct gpio_chip *chip,
307 unsigned long *mask, unsigned long *bits)
308{
309 struct gpiochip_fwd *fwd = gpiochip_get_data(chip);
310 unsigned long flags;
311 int error;
312
313 if (chip->can_sleep) {
314 mutex_lock(&fwd->mlock);
315 error = gpio_fwd_get_multiple(fwd, mask, bits);
316 mutex_unlock(&fwd->mlock);
317 } else {
318 spin_lock_irqsave(&fwd->slock, flags);
319 error = gpio_fwd_get_multiple(fwd, mask, bits);
320 spin_unlock_irqrestore(&fwd->slock, flags);
321 }
322
323 return error;
324}
325
326static void gpio_fwd_set(struct gpio_chip *chip, unsigned int offset, int value)
327{
328 struct gpiochip_fwd *fwd = gpiochip_get_data(chip);
329
330 gpiod_set_value(fwd->descs[offset], value);
331}
332
333static void gpio_fwd_set_multiple(struct gpiochip_fwd *fwd, unsigned long *mask,
334 unsigned long *bits)
335{
336 struct gpio_desc **descs;
337 unsigned long *values;
338 unsigned int i, j = 0;
339
340 /* Both values bitmap and desc pointers are stored in tmp[] */
341 values = &fwd->tmp[0];
342 descs = (void *)&fwd->tmp[BITS_TO_LONGS(fwd->chip.ngpio)];
343
344 for_each_set_bit(i, mask, fwd->chip.ngpio) {
345 __assign_bit(j, values, test_bit(i, bits));
346 descs[j++] = fwd->descs[i];
347 }
348
349 gpiod_set_array_value(j, descs, NULL, values);
350}
351
352static void gpio_fwd_set_multiple_locked(struct gpio_chip *chip,
353 unsigned long *mask, unsigned long *bits)
354{
355 struct gpiochip_fwd *fwd = gpiochip_get_data(chip);
356 unsigned long flags;
357
358 if (chip->can_sleep) {
359 mutex_lock(&fwd->mlock);
360 gpio_fwd_set_multiple(fwd, mask, bits);
361 mutex_unlock(&fwd->mlock);
362 } else {
363 spin_lock_irqsave(&fwd->slock, flags);
364 gpio_fwd_set_multiple(fwd, mask, bits);
365 spin_unlock_irqrestore(&fwd->slock, flags);
366 }
367}
368
369static int gpio_fwd_set_config(struct gpio_chip *chip, unsigned int offset,
370 unsigned long config)
371{
372 struct gpiochip_fwd *fwd = gpiochip_get_data(chip);
373
374 return gpiod_set_config(fwd->descs[offset], config);
375}
376
377/**
378 * gpiochip_fwd_create() - Create a new GPIO forwarder
379 * @dev: Parent device pointer
380 * @ngpios: Number of GPIOs in the forwarder.
381 * @descs: Array containing the GPIO descriptors to forward to.
382 * This array must contain @ngpios entries, and must not be deallocated
383 * before the forwarder has been destroyed again.
384 *
385 * This function creates a new gpiochip, which forwards all GPIO operations to
386 * the passed GPIO descriptors.
387 *
388 * Return: An opaque object pointer, or an ERR_PTR()-encoded negative error
389 * code on failure.
390 */
391static struct gpiochip_fwd *gpiochip_fwd_create(struct device *dev,
392 unsigned int ngpios,
393 struct gpio_desc *descs[])
394{
395 const char *label = dev_name(dev);
396 struct gpiochip_fwd *fwd;
397 struct gpio_chip *chip;
398 unsigned int i;
399 int error;
400
401 fwd = devm_kzalloc(dev, struct_size(fwd, tmp,
402 BITS_TO_LONGS(ngpios) + ngpios), GFP_KERNEL);
403 if (!fwd)
404 return ERR_PTR(-ENOMEM);
405
406 chip = &fwd->chip;
407
408 /*
409 * If any of the GPIO lines are sleeping, then the entire forwarder
410 * will be sleeping.
411 * If any of the chips support .set_config(), then the forwarder will
412 * support setting configs.
413 */
414 for (i = 0; i < ngpios; i++) {
415 struct gpio_chip *parent = gpiod_to_chip(descs[i]);
416
417 dev_dbg(dev, "%u => gpio-%d\n", i, desc_to_gpio(descs[i]));
418
419 if (gpiod_cansleep(descs[i]))
420 chip->can_sleep = true;
421 if (parent && parent->set_config)
422 chip->set_config = gpio_fwd_set_config;
423 }
424
425 chip->label = label;
426 chip->parent = dev;
427 chip->owner = THIS_MODULE;
428 chip->get_direction = gpio_fwd_get_direction;
429 chip->direction_input = gpio_fwd_direction_input;
430 chip->direction_output = gpio_fwd_direction_output;
431 chip->get = gpio_fwd_get;
432 chip->get_multiple = gpio_fwd_get_multiple_locked;
433 chip->set = gpio_fwd_set;
434 chip->set_multiple = gpio_fwd_set_multiple_locked;
435 chip->base = -1;
436 chip->ngpio = ngpios;
437 fwd->descs = descs;
438
439 if (chip->can_sleep)
440 mutex_init(&fwd->mlock);
441 else
442 spin_lock_init(&fwd->slock);
443
444 error = devm_gpiochip_add_data(dev, chip, fwd);
445 if (error)
446 return ERR_PTR(error);
447
448 return fwd;
449}
450
451
452/*
453 * GPIO Aggregator platform device
454 */
455
456static int gpio_aggregator_probe(struct platform_device *pdev)
457{
458 struct device *dev = &pdev->dev;
459 struct gpio_desc **descs;
460 struct gpiochip_fwd *fwd;
461 int i, n;
462
463 n = gpiod_count(dev, NULL);
464 if (n < 0)
465 return n;
466
467 descs = devm_kmalloc_array(dev, n, sizeof(*descs), GFP_KERNEL);
468 if (!descs)
469 return -ENOMEM;
470
471 for (i = 0; i < n; i++) {
472 descs[i] = devm_gpiod_get_index(dev, NULL, i, GPIOD_ASIS);
473 if (IS_ERR(descs[i]))
474 return PTR_ERR(descs[i]);
475 }
476
477 fwd = gpiochip_fwd_create(dev, n, descs);
478 if (IS_ERR(fwd))
479 return PTR_ERR(fwd);
480
481 platform_set_drvdata(pdev, fwd);
482 return 0;
483}
484
485#ifdef CONFIG_OF
486static const struct of_device_id gpio_aggregator_dt_ids[] = {
487 /*
488 * Add GPIO-operated devices controlled from userspace below,
489 * or use "driver_override" in sysfs
490 */
491 {}
492};
493MODULE_DEVICE_TABLE(of, gpio_aggregator_dt_ids);
494#endif
495
496static struct platform_driver gpio_aggregator_driver = {
497 .probe = gpio_aggregator_probe,
498 .driver = {
499 .name = DRV_NAME,
500 .groups = gpio_aggregator_groups,
501 .of_match_table = of_match_ptr(gpio_aggregator_dt_ids),
502 },
503};
504
505static int __init gpio_aggregator_init(void)
506{
507 return platform_driver_register(&gpio_aggregator_driver);
508}
509module_init(gpio_aggregator_init);
510
511static void __exit gpio_aggregator_exit(void)
512{
513 gpio_aggregator_remove_all();
514 platform_driver_unregister(&gpio_aggregator_driver);
515}
516module_exit(gpio_aggregator_exit);
517
518MODULE_AUTHOR("Geert Uytterhoeven <geert+renesas@glider.be>");
519MODULE_DESCRIPTION("GPIO Aggregator");
520MODULE_LICENSE("GPL v2");