1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * GPIO Greybus driver.
4 *
5 * Copyright 2014 Google Inc.
6 * Copyright 2014 Linaro Ltd.
7 */
8
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/slab.h>
12 #include <linux/irq.h>
13 #include <linux/irqdomain.h>
14 #include <linux/gpio/driver.h>
15 #include <linux/mutex.h>
16 #include <linux/greybus.h>
17
18 #include "gbphy.h"
19
20 struct gb_gpio_line {
21 /* The following has to be an array of line_max entries */
22 /* --> make them just a flags field */
23 u8 active: 1,
24 direction: 1, /* 0 = output, 1 = input */
25 value: 1; /* 0 = low, 1 = high */
26 u16 debounce_usec;
27
28 u8 irq_type;
29 bool irq_type_pending;
30 bool masked;
31 bool masked_pending;
32 };
33
34 struct gb_gpio_controller {
35 struct gbphy_device *gbphy_dev;
36 struct gb_connection *connection;
37 u8 line_max; /* max line number */
38 struct gb_gpio_line *lines;
39
40 struct gpio_chip chip;
41 struct irq_chip irqc;
42 struct mutex irq_lock;
43 };
44
irq_data_to_gpio_chip(struct irq_data * d)45 static struct gpio_chip *irq_data_to_gpio_chip(struct irq_data *d)
46 {
47 return d->domain->host_data;
48 }
49
gb_gpio_line_count_operation(struct gb_gpio_controller * ggc)50 static int gb_gpio_line_count_operation(struct gb_gpio_controller *ggc)
51 {
52 struct gb_gpio_line_count_response response;
53 int ret;
54
55 ret = gb_operation_sync(ggc->connection, GB_GPIO_TYPE_LINE_COUNT,
56 NULL, 0, &response, sizeof(response));
57 if (!ret)
58 ggc->line_max = response.count;
59 return ret;
60 }
61
gb_gpio_activate_operation(struct gb_gpio_controller * ggc,u8 which)62 static int gb_gpio_activate_operation(struct gb_gpio_controller *ggc, u8 which)
63 {
64 struct gb_gpio_activate_request request;
65 struct gbphy_device *gbphy_dev = ggc->gbphy_dev;
66 int ret;
67
68 ret = gbphy_runtime_get_sync(gbphy_dev);
69 if (ret)
70 return ret;
71
72 request.which = which;
73 ret = gb_operation_sync(ggc->connection, GB_GPIO_TYPE_ACTIVATE,
74 &request, sizeof(request), NULL, 0);
75 if (ret) {
76 gbphy_runtime_put_autosuspend(gbphy_dev);
77 return ret;
78 }
79
80 ggc->lines[which].active = true;
81
82 return 0;
83 }
84
gb_gpio_deactivate_operation(struct gb_gpio_controller * ggc,u8 which)85 static void gb_gpio_deactivate_operation(struct gb_gpio_controller *ggc,
86 u8 which)
87 {
88 struct gbphy_device *gbphy_dev = ggc->gbphy_dev;
89 struct device *dev = &gbphy_dev->dev;
90 struct gb_gpio_deactivate_request request;
91 int ret;
92
93 request.which = which;
94 ret = gb_operation_sync(ggc->connection, GB_GPIO_TYPE_DEACTIVATE,
95 &request, sizeof(request), NULL, 0);
96 if (ret) {
97 dev_err(dev, "failed to deactivate gpio %u\n", which);
98 goto out_pm_put;
99 }
100
101 ggc->lines[which].active = false;
102
103 out_pm_put:
104 gbphy_runtime_put_autosuspend(gbphy_dev);
105 }
106
gb_gpio_get_direction_operation(struct gb_gpio_controller * ggc,u8 which)107 static int gb_gpio_get_direction_operation(struct gb_gpio_controller *ggc,
108 u8 which)
109 {
110 struct device *dev = &ggc->gbphy_dev->dev;
111 struct gb_gpio_get_direction_request request;
112 struct gb_gpio_get_direction_response response;
113 int ret;
114 u8 direction;
115
116 request.which = which;
117 ret = gb_operation_sync(ggc->connection, GB_GPIO_TYPE_GET_DIRECTION,
118 &request, sizeof(request),
119 &response, sizeof(response));
120 if (ret)
121 return ret;
122
123 direction = response.direction;
124 if (direction && direction != 1) {
125 dev_warn(dev, "gpio %u direction was %u (should be 0 or 1)\n",
126 which, direction);
127 }
128 ggc->lines[which].direction = direction ? 1 : 0;
129 return 0;
130 }
131
gb_gpio_direction_in_operation(struct gb_gpio_controller * ggc,u8 which)132 static int gb_gpio_direction_in_operation(struct gb_gpio_controller *ggc,
133 u8 which)
134 {
135 struct gb_gpio_direction_in_request request;
136 int ret;
137
138 request.which = which;
139 ret = gb_operation_sync(ggc->connection, GB_GPIO_TYPE_DIRECTION_IN,
140 &request, sizeof(request), NULL, 0);
141 if (!ret)
142 ggc->lines[which].direction = 1;
143 return ret;
144 }
145
gb_gpio_direction_out_operation(struct gb_gpio_controller * ggc,u8 which,bool value_high)146 static int gb_gpio_direction_out_operation(struct gb_gpio_controller *ggc,
147 u8 which, bool value_high)
148 {
149 struct gb_gpio_direction_out_request request;
150 int ret;
151
152 request.which = which;
153 request.value = value_high ? 1 : 0;
154 ret = gb_operation_sync(ggc->connection, GB_GPIO_TYPE_DIRECTION_OUT,
155 &request, sizeof(request), NULL, 0);
156 if (!ret)
157 ggc->lines[which].direction = 0;
158 return ret;
159 }
160
gb_gpio_get_value_operation(struct gb_gpio_controller * ggc,u8 which)161 static int gb_gpio_get_value_operation(struct gb_gpio_controller *ggc,
162 u8 which)
163 {
164 struct device *dev = &ggc->gbphy_dev->dev;
165 struct gb_gpio_get_value_request request;
166 struct gb_gpio_get_value_response response;
167 int ret;
168 u8 value;
169
170 request.which = which;
171 ret = gb_operation_sync(ggc->connection, GB_GPIO_TYPE_GET_VALUE,
172 &request, sizeof(request),
173 &response, sizeof(response));
174 if (ret) {
175 dev_err(dev, "failed to get value of gpio %u\n", which);
176 return ret;
177 }
178
179 value = response.value;
180 if (value && value != 1) {
181 dev_warn(dev, "gpio %u value was %u (should be 0 or 1)\n",
182 which, value);
183 }
184 ggc->lines[which].value = value ? 1 : 0;
185 return 0;
186 }
187
gb_gpio_set_value_operation(struct gb_gpio_controller * ggc,u8 which,bool value_high)188 static int gb_gpio_set_value_operation(struct gb_gpio_controller *ggc,
189 u8 which, bool value_high)
190 {
191 struct device *dev = &ggc->gbphy_dev->dev;
192 struct gb_gpio_set_value_request request;
193 int ret;
194
195 request.which = which;
196 request.value = value_high ? 1 : 0;
197 ret = gb_operation_sync(ggc->connection, GB_GPIO_TYPE_SET_VALUE,
198 &request, sizeof(request), NULL, 0);
199 if (ret) {
200 dev_err(dev, "failed to set value of gpio %u\n", which);
201 return ret;
202 }
203
204 ggc->lines[which].value = request.value;
205
206 return 0;
207 }
208
gb_gpio_set_debounce_operation(struct gb_gpio_controller * ggc,u8 which,u16 debounce_usec)209 static int gb_gpio_set_debounce_operation(struct gb_gpio_controller *ggc,
210 u8 which, u16 debounce_usec)
211 {
212 struct gb_gpio_set_debounce_request request;
213 int ret;
214
215 request.which = which;
216 request.usec = cpu_to_le16(debounce_usec);
217 ret = gb_operation_sync(ggc->connection, GB_GPIO_TYPE_SET_DEBOUNCE,
218 &request, sizeof(request), NULL, 0);
219 if (!ret)
220 ggc->lines[which].debounce_usec = debounce_usec;
221 return ret;
222 }
223
_gb_gpio_irq_mask(struct gb_gpio_controller * ggc,u8 hwirq)224 static void _gb_gpio_irq_mask(struct gb_gpio_controller *ggc, u8 hwirq)
225 {
226 struct device *dev = &ggc->gbphy_dev->dev;
227 struct gb_gpio_irq_mask_request request;
228 int ret;
229
230 request.which = hwirq;
231 ret = gb_operation_sync(ggc->connection,
232 GB_GPIO_TYPE_IRQ_MASK,
233 &request, sizeof(request), NULL, 0);
234 if (ret)
235 dev_err(dev, "failed to mask irq: %d\n", ret);
236 }
237
_gb_gpio_irq_unmask(struct gb_gpio_controller * ggc,u8 hwirq)238 static void _gb_gpio_irq_unmask(struct gb_gpio_controller *ggc, u8 hwirq)
239 {
240 struct device *dev = &ggc->gbphy_dev->dev;
241 struct gb_gpio_irq_unmask_request request;
242 int ret;
243
244 request.which = hwirq;
245 ret = gb_operation_sync(ggc->connection,
246 GB_GPIO_TYPE_IRQ_UNMASK,
247 &request, sizeof(request), NULL, 0);
248 if (ret)
249 dev_err(dev, "failed to unmask irq: %d\n", ret);
250 }
251
_gb_gpio_irq_set_type(struct gb_gpio_controller * ggc,u8 hwirq,u8 type)252 static void _gb_gpio_irq_set_type(struct gb_gpio_controller *ggc,
253 u8 hwirq, u8 type)
254 {
255 struct device *dev = &ggc->gbphy_dev->dev;
256 struct gb_gpio_irq_type_request request;
257 int ret;
258
259 request.which = hwirq;
260 request.type = type;
261
262 ret = gb_operation_sync(ggc->connection,
263 GB_GPIO_TYPE_IRQ_TYPE,
264 &request, sizeof(request), NULL, 0);
265 if (ret)
266 dev_err(dev, "failed to set irq type: %d\n", ret);
267 }
268
gb_gpio_irq_mask(struct irq_data * d)269 static void gb_gpio_irq_mask(struct irq_data *d)
270 {
271 struct gpio_chip *chip = irq_data_to_gpio_chip(d);
272 struct gb_gpio_controller *ggc = gpiochip_get_data(chip);
273 struct gb_gpio_line *line = &ggc->lines[d->hwirq];
274
275 line->masked = true;
276 line->masked_pending = true;
277 }
278
gb_gpio_irq_unmask(struct irq_data * d)279 static void gb_gpio_irq_unmask(struct irq_data *d)
280 {
281 struct gpio_chip *chip = irq_data_to_gpio_chip(d);
282 struct gb_gpio_controller *ggc = gpiochip_get_data(chip);
283 struct gb_gpio_line *line = &ggc->lines[d->hwirq];
284
285 line->masked = false;
286 line->masked_pending = true;
287 }
288
gb_gpio_irq_set_type(struct irq_data * d,unsigned int type)289 static int gb_gpio_irq_set_type(struct irq_data *d, unsigned int type)
290 {
291 struct gpio_chip *chip = irq_data_to_gpio_chip(d);
292 struct gb_gpio_controller *ggc = gpiochip_get_data(chip);
293 struct gb_gpio_line *line = &ggc->lines[d->hwirq];
294 struct device *dev = &ggc->gbphy_dev->dev;
295 u8 irq_type;
296
297 switch (type) {
298 case IRQ_TYPE_NONE:
299 irq_type = GB_GPIO_IRQ_TYPE_NONE;
300 break;
301 case IRQ_TYPE_EDGE_RISING:
302 irq_type = GB_GPIO_IRQ_TYPE_EDGE_RISING;
303 break;
304 case IRQ_TYPE_EDGE_FALLING:
305 irq_type = GB_GPIO_IRQ_TYPE_EDGE_FALLING;
306 break;
307 case IRQ_TYPE_EDGE_BOTH:
308 irq_type = GB_GPIO_IRQ_TYPE_EDGE_BOTH;
309 break;
310 case IRQ_TYPE_LEVEL_LOW:
311 irq_type = GB_GPIO_IRQ_TYPE_LEVEL_LOW;
312 break;
313 case IRQ_TYPE_LEVEL_HIGH:
314 irq_type = GB_GPIO_IRQ_TYPE_LEVEL_HIGH;
315 break;
316 default:
317 dev_err(dev, "unsupported irq type: %u\n", type);
318 return -EINVAL;
319 }
320
321 line->irq_type = irq_type;
322 line->irq_type_pending = true;
323
324 return 0;
325 }
326
gb_gpio_irq_bus_lock(struct irq_data * d)327 static void gb_gpio_irq_bus_lock(struct irq_data *d)
328 {
329 struct gpio_chip *chip = irq_data_to_gpio_chip(d);
330 struct gb_gpio_controller *ggc = gpiochip_get_data(chip);
331
332 mutex_lock(&ggc->irq_lock);
333 }
334
gb_gpio_irq_bus_sync_unlock(struct irq_data * d)335 static void gb_gpio_irq_bus_sync_unlock(struct irq_data *d)
336 {
337 struct gpio_chip *chip = irq_data_to_gpio_chip(d);
338 struct gb_gpio_controller *ggc = gpiochip_get_data(chip);
339 struct gb_gpio_line *line = &ggc->lines[d->hwirq];
340
341 if (line->irq_type_pending) {
342 _gb_gpio_irq_set_type(ggc, d->hwirq, line->irq_type);
343 line->irq_type_pending = false;
344 }
345
346 if (line->masked_pending) {
347 if (line->masked)
348 _gb_gpio_irq_mask(ggc, d->hwirq);
349 else
350 _gb_gpio_irq_unmask(ggc, d->hwirq);
351 line->masked_pending = false;
352 }
353
354 mutex_unlock(&ggc->irq_lock);
355 }
356
gb_gpio_request_handler(struct gb_operation * op)357 static int gb_gpio_request_handler(struct gb_operation *op)
358 {
359 struct gb_connection *connection = op->connection;
360 struct gb_gpio_controller *ggc = gb_connection_get_data(connection);
361 struct device *dev = &ggc->gbphy_dev->dev;
362 struct gb_message *request;
363 struct gb_gpio_irq_event_request *event;
364 u8 type = op->type;
365 int irq, ret;
366
367 if (type != GB_GPIO_TYPE_IRQ_EVENT) {
368 dev_err(dev, "unsupported unsolicited request: %u\n", type);
369 return -EINVAL;
370 }
371
372 request = op->request;
373
374 if (request->payload_size < sizeof(*event)) {
375 dev_err(dev, "short event received (%zu < %zu)\n",
376 request->payload_size, sizeof(*event));
377 return -EINVAL;
378 }
379
380 event = request->payload;
381 if (event->which > ggc->line_max) {
382 dev_err(dev, "invalid hw irq: %d\n", event->which);
383 return -EINVAL;
384 }
385
386 irq = irq_find_mapping(ggc->chip.irq.domain, event->which);
387 if (!irq) {
388 dev_err(dev, "failed to find IRQ\n");
389 return -EINVAL;
390 }
391
392 ret = generic_handle_irq_safe(irq);
393 if (ret)
394 dev_err(dev, "failed to invoke irq handler\n");
395
396 return ret;
397 }
398
gb_gpio_request(struct gpio_chip * chip,unsigned int offset)399 static int gb_gpio_request(struct gpio_chip *chip, unsigned int offset)
400 {
401 struct gb_gpio_controller *ggc = gpiochip_get_data(chip);
402
403 return gb_gpio_activate_operation(ggc, (u8)offset);
404 }
405
gb_gpio_free(struct gpio_chip * chip,unsigned int offset)406 static void gb_gpio_free(struct gpio_chip *chip, unsigned int offset)
407 {
408 struct gb_gpio_controller *ggc = gpiochip_get_data(chip);
409
410 gb_gpio_deactivate_operation(ggc, (u8)offset);
411 }
412
gb_gpio_get_direction(struct gpio_chip * chip,unsigned int offset)413 static int gb_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
414 {
415 struct gb_gpio_controller *ggc = gpiochip_get_data(chip);
416 u8 which;
417 int ret;
418
419 which = (u8)offset;
420 ret = gb_gpio_get_direction_operation(ggc, which);
421 if (ret)
422 return ret;
423
424 return ggc->lines[which].direction ? 1 : 0;
425 }
426
gb_gpio_direction_input(struct gpio_chip * chip,unsigned int offset)427 static int gb_gpio_direction_input(struct gpio_chip *chip, unsigned int offset)
428 {
429 struct gb_gpio_controller *ggc = gpiochip_get_data(chip);
430
431 return gb_gpio_direction_in_operation(ggc, (u8)offset);
432 }
433
gb_gpio_direction_output(struct gpio_chip * chip,unsigned int offset,int value)434 static int gb_gpio_direction_output(struct gpio_chip *chip, unsigned int offset,
435 int value)
436 {
437 struct gb_gpio_controller *ggc = gpiochip_get_data(chip);
438
439 return gb_gpio_direction_out_operation(ggc, (u8)offset, !!value);
440 }
441
gb_gpio_get(struct gpio_chip * chip,unsigned int offset)442 static int gb_gpio_get(struct gpio_chip *chip, unsigned int offset)
443 {
444 struct gb_gpio_controller *ggc = gpiochip_get_data(chip);
445 u8 which;
446 int ret;
447
448 which = (u8)offset;
449 ret = gb_gpio_get_value_operation(ggc, which);
450 if (ret)
451 return ret;
452
453 return ggc->lines[which].value;
454 }
455
gb_gpio_set(struct gpio_chip * chip,unsigned int offset,int value)456 static int gb_gpio_set(struct gpio_chip *chip, unsigned int offset, int value)
457 {
458 struct gb_gpio_controller *ggc = gpiochip_get_data(chip);
459
460 return gb_gpio_set_value_operation(ggc, (u8)offset, !!value);
461 }
462
gb_gpio_set_config(struct gpio_chip * chip,unsigned int offset,unsigned long config)463 static int gb_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
464 unsigned long config)
465 {
466 struct gb_gpio_controller *ggc = gpiochip_get_data(chip);
467 u32 debounce;
468
469 if (pinconf_to_config_param(config) != PIN_CONFIG_INPUT_DEBOUNCE)
470 return -ENOTSUPP;
471
472 debounce = pinconf_to_config_argument(config);
473 if (debounce > U16_MAX)
474 return -EINVAL;
475
476 return gb_gpio_set_debounce_operation(ggc, (u8)offset, (u16)debounce);
477 }
478
gb_gpio_controller_setup(struct gb_gpio_controller * ggc)479 static int gb_gpio_controller_setup(struct gb_gpio_controller *ggc)
480 {
481 int ret;
482
483 /* Now find out how many lines there are */
484 ret = gb_gpio_line_count_operation(ggc);
485 if (ret)
486 return ret;
487
488 ggc->lines = kcalloc(ggc->line_max + 1, sizeof(*ggc->lines),
489 GFP_KERNEL);
490 if (!ggc->lines)
491 return -ENOMEM;
492
493 return ret;
494 }
495
gb_gpio_probe(struct gbphy_device * gbphy_dev,const struct gbphy_device_id * id)496 static int gb_gpio_probe(struct gbphy_device *gbphy_dev,
497 const struct gbphy_device_id *id)
498 {
499 struct gb_connection *connection;
500 struct gb_gpio_controller *ggc;
501 struct gpio_chip *gpio;
502 struct gpio_irq_chip *girq;
503 struct irq_chip *irqc;
504 int ret;
505
506 ggc = kzalloc(sizeof(*ggc), GFP_KERNEL);
507 if (!ggc)
508 return -ENOMEM;
509
510 connection =
511 gb_connection_create(gbphy_dev->bundle,
512 le16_to_cpu(gbphy_dev->cport_desc->id),
513 gb_gpio_request_handler);
514 if (IS_ERR(connection)) {
515 ret = PTR_ERR(connection);
516 goto exit_ggc_free;
517 }
518
519 ggc->connection = connection;
520 gb_connection_set_data(connection, ggc);
521 ggc->gbphy_dev = gbphy_dev;
522 gb_gbphy_set_data(gbphy_dev, ggc);
523
524 ret = gb_connection_enable_tx(connection);
525 if (ret)
526 goto exit_connection_destroy;
527
528 ret = gb_gpio_controller_setup(ggc);
529 if (ret)
530 goto exit_connection_disable;
531
532 irqc = &ggc->irqc;
533 irqc->irq_mask = gb_gpio_irq_mask;
534 irqc->irq_unmask = gb_gpio_irq_unmask;
535 irqc->irq_set_type = gb_gpio_irq_set_type;
536 irqc->irq_bus_lock = gb_gpio_irq_bus_lock;
537 irqc->irq_bus_sync_unlock = gb_gpio_irq_bus_sync_unlock;
538 irqc->name = "greybus_gpio";
539
540 mutex_init(&ggc->irq_lock);
541
542 gpio = &ggc->chip;
543
544 gpio->label = "greybus_gpio";
545 gpio->parent = &gbphy_dev->dev;
546 gpio->owner = THIS_MODULE;
547
548 gpio->request = gb_gpio_request;
549 gpio->free = gb_gpio_free;
550 gpio->get_direction = gb_gpio_get_direction;
551 gpio->direction_input = gb_gpio_direction_input;
552 gpio->direction_output = gb_gpio_direction_output;
553 gpio->get = gb_gpio_get;
554 gpio->set_rv = gb_gpio_set;
555 gpio->set_config = gb_gpio_set_config;
556 gpio->base = -1; /* Allocate base dynamically */
557 gpio->ngpio = ggc->line_max + 1;
558 gpio->can_sleep = true;
559
560 girq = &gpio->irq;
561 girq->chip = irqc;
562 /* The event comes from the outside so no parent handler */
563 girq->parent_handler = NULL;
564 girq->num_parents = 0;
565 girq->parents = NULL;
566 girq->default_type = IRQ_TYPE_NONE;
567 girq->handler = handle_level_irq;
568
569 ret = gb_connection_enable(connection);
570 if (ret)
571 goto exit_line_free;
572
573 ret = gpiochip_add_data(gpio, ggc);
574 if (ret) {
575 dev_err(&gbphy_dev->dev, "failed to add gpio chip: %d\n", ret);
576 goto exit_line_free;
577 }
578
579 gbphy_runtime_put_autosuspend(gbphy_dev);
580 return 0;
581
582 exit_line_free:
583 kfree(ggc->lines);
584 exit_connection_disable:
585 gb_connection_disable(connection);
586 exit_connection_destroy:
587 gb_connection_destroy(connection);
588 exit_ggc_free:
589 kfree(ggc);
590 return ret;
591 }
592
gb_gpio_remove(struct gbphy_device * gbphy_dev)593 static void gb_gpio_remove(struct gbphy_device *gbphy_dev)
594 {
595 struct gb_gpio_controller *ggc = gb_gbphy_get_data(gbphy_dev);
596 struct gb_connection *connection = ggc->connection;
597 int ret;
598
599 ret = gbphy_runtime_get_sync(gbphy_dev);
600 if (ret)
601 gbphy_runtime_get_noresume(gbphy_dev);
602
603 gb_connection_disable_rx(connection);
604 gpiochip_remove(&ggc->chip);
605 gb_connection_disable(connection);
606 gb_connection_destroy(connection);
607 kfree(ggc->lines);
608 kfree(ggc);
609 }
610
611 static const struct gbphy_device_id gb_gpio_id_table[] = {
612 { GBPHY_PROTOCOL(GREYBUS_PROTOCOL_GPIO) },
613 { },
614 };
615 MODULE_DEVICE_TABLE(gbphy, gb_gpio_id_table);
616
617 static struct gbphy_driver gpio_driver = {
618 .name = "gpio",
619 .probe = gb_gpio_probe,
620 .remove = gb_gpio_remove,
621 .id_table = gb_gpio_id_table,
622 };
623
624 module_gbphy_driver(gpio_driver);
625 MODULE_DESCRIPTION("GPIO Greybus driver");
626 MODULE_LICENSE("GPL v2");
627