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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
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);
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
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
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
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
238
239
240struct gpiochip_fwd {
241 struct gpio_chip chip;
242 struct gpio_desc **descs;
243 union {
244 struct mutex mlock;
245 spinlock_t slock;
246 };
247 unsigned long tmp[];
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
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
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}
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389
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
410
411
412
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
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
489
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");
521
