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 if (ggc->lines[which].direction == 1) {
196 dev_warn(dev, "refusing to set value of input gpio %u\n",
197 which);
198 return -EPERM;
199 }
200
201 request.which = which;
202 request.value = value_high ? 1 : 0;
203 ret = gb_operation_sync(ggc->connection, GB_GPIO_TYPE_SET_VALUE,
204 &request, sizeof(request), NULL, 0);
205 if (ret) {
206 dev_err(dev, "failed to set value of gpio %u\n", which);
207 return ret;
208 }
209
210 ggc->lines[which].value = request.value;
211
212 return 0;
213 }
214
gb_gpio_set_debounce_operation(struct gb_gpio_controller * ggc,u8 which,u16 debounce_usec)215 static int gb_gpio_set_debounce_operation(struct gb_gpio_controller *ggc,
216 u8 which, u16 debounce_usec)
217 {
218 struct gb_gpio_set_debounce_request request;
219 int ret;
220
221 request.which = which;
222 request.usec = cpu_to_le16(debounce_usec);
223 ret = gb_operation_sync(ggc->connection, GB_GPIO_TYPE_SET_DEBOUNCE,
224 &request, sizeof(request), NULL, 0);
225 if (!ret)
226 ggc->lines[which].debounce_usec = debounce_usec;
227 return ret;
228 }
229
_gb_gpio_irq_mask(struct gb_gpio_controller * ggc,u8 hwirq)230 static void _gb_gpio_irq_mask(struct gb_gpio_controller *ggc, u8 hwirq)
231 {
232 struct device *dev = &ggc->gbphy_dev->dev;
233 struct gb_gpio_irq_mask_request request;
234 int ret;
235
236 request.which = hwirq;
237 ret = gb_operation_sync(ggc->connection,
238 GB_GPIO_TYPE_IRQ_MASK,
239 &request, sizeof(request), NULL, 0);
240 if (ret)
241 dev_err(dev, "failed to mask irq: %d\n", ret);
242 }
243
_gb_gpio_irq_unmask(struct gb_gpio_controller * ggc,u8 hwirq)244 static void _gb_gpio_irq_unmask(struct gb_gpio_controller *ggc, u8 hwirq)
245 {
246 struct device *dev = &ggc->gbphy_dev->dev;
247 struct gb_gpio_irq_unmask_request request;
248 int ret;
249
250 request.which = hwirq;
251 ret = gb_operation_sync(ggc->connection,
252 GB_GPIO_TYPE_IRQ_UNMASK,
253 &request, sizeof(request), NULL, 0);
254 if (ret)
255 dev_err(dev, "failed to unmask irq: %d\n", ret);
256 }
257
_gb_gpio_irq_set_type(struct gb_gpio_controller * ggc,u8 hwirq,u8 type)258 static void _gb_gpio_irq_set_type(struct gb_gpio_controller *ggc,
259 u8 hwirq, u8 type)
260 {
261 struct device *dev = &ggc->gbphy_dev->dev;
262 struct gb_gpio_irq_type_request request;
263 int ret;
264
265 request.which = hwirq;
266 request.type = type;
267
268 ret = gb_operation_sync(ggc->connection,
269 GB_GPIO_TYPE_IRQ_TYPE,
270 &request, sizeof(request), NULL, 0);
271 if (ret)
272 dev_err(dev, "failed to set irq type: %d\n", ret);
273 }
274
gb_gpio_irq_mask(struct irq_data * d)275 static void gb_gpio_irq_mask(struct irq_data *d)
276 {
277 struct gpio_chip *chip = irq_data_to_gpio_chip(d);
278 struct gb_gpio_controller *ggc = gpiochip_get_data(chip);
279 struct gb_gpio_line *line = &ggc->lines[d->hwirq];
280
281 line->masked = true;
282 line->masked_pending = true;
283 }
284
gb_gpio_irq_unmask(struct irq_data * d)285 static void gb_gpio_irq_unmask(struct irq_data *d)
286 {
287 struct gpio_chip *chip = irq_data_to_gpio_chip(d);
288 struct gb_gpio_controller *ggc = gpiochip_get_data(chip);
289 struct gb_gpio_line *line = &ggc->lines[d->hwirq];
290
291 line->masked = false;
292 line->masked_pending = true;
293 }
294
gb_gpio_irq_set_type(struct irq_data * d,unsigned int type)295 static int gb_gpio_irq_set_type(struct irq_data *d, unsigned int type)
296 {
297 struct gpio_chip *chip = irq_data_to_gpio_chip(d);
298 struct gb_gpio_controller *ggc = gpiochip_get_data(chip);
299 struct gb_gpio_line *line = &ggc->lines[d->hwirq];
300 struct device *dev = &ggc->gbphy_dev->dev;
301 u8 irq_type;
302
303 switch (type) {
304 case IRQ_TYPE_NONE:
305 irq_type = GB_GPIO_IRQ_TYPE_NONE;
306 break;
307 case IRQ_TYPE_EDGE_RISING:
308 irq_type = GB_GPIO_IRQ_TYPE_EDGE_RISING;
309 break;
310 case IRQ_TYPE_EDGE_FALLING:
311 irq_type = GB_GPIO_IRQ_TYPE_EDGE_FALLING;
312 break;
313 case IRQ_TYPE_EDGE_BOTH:
314 irq_type = GB_GPIO_IRQ_TYPE_EDGE_BOTH;
315 break;
316 case IRQ_TYPE_LEVEL_LOW:
317 irq_type = GB_GPIO_IRQ_TYPE_LEVEL_LOW;
318 break;
319 case IRQ_TYPE_LEVEL_HIGH:
320 irq_type = GB_GPIO_IRQ_TYPE_LEVEL_HIGH;
321 break;
322 default:
323 dev_err(dev, "unsupported irq type: %u\n", type);
324 return -EINVAL;
325 }
326
327 line->irq_type = irq_type;
328 line->irq_type_pending = true;
329
330 return 0;
331 }
332
gb_gpio_irq_bus_lock(struct irq_data * d)333 static void gb_gpio_irq_bus_lock(struct irq_data *d)
334 {
335 struct gpio_chip *chip = irq_data_to_gpio_chip(d);
336 struct gb_gpio_controller *ggc = gpiochip_get_data(chip);
337
338 mutex_lock(&ggc->irq_lock);
339 }
340
gb_gpio_irq_bus_sync_unlock(struct irq_data * d)341 static void gb_gpio_irq_bus_sync_unlock(struct irq_data *d)
342 {
343 struct gpio_chip *chip = irq_data_to_gpio_chip(d);
344 struct gb_gpio_controller *ggc = gpiochip_get_data(chip);
345 struct gb_gpio_line *line = &ggc->lines[d->hwirq];
346
347 if (line->irq_type_pending) {
348 _gb_gpio_irq_set_type(ggc, d->hwirq, line->irq_type);
349 line->irq_type_pending = false;
350 }
351
352 if (line->masked_pending) {
353 if (line->masked)
354 _gb_gpio_irq_mask(ggc, d->hwirq);
355 else
356 _gb_gpio_irq_unmask(ggc, d->hwirq);
357 line->masked_pending = false;
358 }
359
360 mutex_unlock(&ggc->irq_lock);
361 }
362
gb_gpio_request_handler(struct gb_operation * op)363 static int gb_gpio_request_handler(struct gb_operation *op)
364 {
365 struct gb_connection *connection = op->connection;
366 struct gb_gpio_controller *ggc = gb_connection_get_data(connection);
367 struct device *dev = &ggc->gbphy_dev->dev;
368 struct gb_message *request;
369 struct gb_gpio_irq_event_request *event;
370 u8 type = op->type;
371 int irq, ret;
372
373 if (type != GB_GPIO_TYPE_IRQ_EVENT) {
374 dev_err(dev, "unsupported unsolicited request: %u\n", type);
375 return -EINVAL;
376 }
377
378 request = op->request;
379
380 if (request->payload_size < sizeof(*event)) {
381 dev_err(dev, "short event received (%zu < %zu)\n",
382 request->payload_size, sizeof(*event));
383 return -EINVAL;
384 }
385
386 event = request->payload;
387 if (event->which > ggc->line_max) {
388 dev_err(dev, "invalid hw irq: %d\n", event->which);
389 return -EINVAL;
390 }
391
392 irq = irq_find_mapping(ggc->chip.irq.domain, event->which);
393 if (!irq) {
394 dev_err(dev, "failed to find IRQ\n");
395 return -EINVAL;
396 }
397
398 ret = generic_handle_irq_safe(irq);
399 if (ret)
400 dev_err(dev, "failed to invoke irq handler\n");
401
402 return ret;
403 }
404
gb_gpio_request(struct gpio_chip * chip,unsigned int offset)405 static int gb_gpio_request(struct gpio_chip *chip, unsigned int offset)
406 {
407 struct gb_gpio_controller *ggc = gpiochip_get_data(chip);
408
409 return gb_gpio_activate_operation(ggc, (u8)offset);
410 }
411
gb_gpio_free(struct gpio_chip * chip,unsigned int offset)412 static void gb_gpio_free(struct gpio_chip *chip, unsigned int offset)
413 {
414 struct gb_gpio_controller *ggc = gpiochip_get_data(chip);
415
416 gb_gpio_deactivate_operation(ggc, (u8)offset);
417 }
418
gb_gpio_get_direction(struct gpio_chip * chip,unsigned int offset)419 static int gb_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
420 {
421 struct gb_gpio_controller *ggc = gpiochip_get_data(chip);
422 u8 which;
423 int ret;
424
425 which = (u8)offset;
426 ret = gb_gpio_get_direction_operation(ggc, which);
427 if (ret)
428 return ret;
429
430 return ggc->lines[which].direction ? 1 : 0;
431 }
432
gb_gpio_direction_input(struct gpio_chip * chip,unsigned int offset)433 static int gb_gpio_direction_input(struct gpio_chip *chip, unsigned int offset)
434 {
435 struct gb_gpio_controller *ggc = gpiochip_get_data(chip);
436
437 return gb_gpio_direction_in_operation(ggc, (u8)offset);
438 }
439
gb_gpio_direction_output(struct gpio_chip * chip,unsigned int offset,int value)440 static int gb_gpio_direction_output(struct gpio_chip *chip, unsigned int offset,
441 int value)
442 {
443 struct gb_gpio_controller *ggc = gpiochip_get_data(chip);
444
445 return gb_gpio_direction_out_operation(ggc, (u8)offset, !!value);
446 }
447
gb_gpio_get(struct gpio_chip * chip,unsigned int offset)448 static int gb_gpio_get(struct gpio_chip *chip, unsigned int offset)
449 {
450 struct gb_gpio_controller *ggc = gpiochip_get_data(chip);
451 u8 which;
452 int ret;
453
454 which = (u8)offset;
455 ret = gb_gpio_get_value_operation(ggc, which);
456 if (ret)
457 return ret;
458
459 return ggc->lines[which].value;
460 }
461
gb_gpio_set(struct gpio_chip * chip,unsigned int offset,int value)462 static int gb_gpio_set(struct gpio_chip *chip, unsigned int offset, int value)
463 {
464 struct gb_gpio_controller *ggc = gpiochip_get_data(chip);
465
466 return gb_gpio_set_value_operation(ggc, (u8)offset, !!value);
467 }
468
gb_gpio_set_config(struct gpio_chip * chip,unsigned int offset,unsigned long config)469 static int gb_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
470 unsigned long config)
471 {
472 struct gb_gpio_controller *ggc = gpiochip_get_data(chip);
473 u32 debounce;
474
475 if (pinconf_to_config_param(config) != PIN_CONFIG_INPUT_DEBOUNCE)
476 return -ENOTSUPP;
477
478 debounce = pinconf_to_config_argument(config);
479 if (debounce > U16_MAX)
480 return -EINVAL;
481
482 return gb_gpio_set_debounce_operation(ggc, (u8)offset, (u16)debounce);
483 }
484
gb_gpio_controller_setup(struct gb_gpio_controller * ggc)485 static int gb_gpio_controller_setup(struct gb_gpio_controller *ggc)
486 {
487 int ret;
488
489 /* Now find out how many lines there are */
490 ret = gb_gpio_line_count_operation(ggc);
491 if (ret)
492 return ret;
493
494 ggc->lines = kcalloc(ggc->line_max + 1, sizeof(*ggc->lines),
495 GFP_KERNEL);
496 if (!ggc->lines)
497 return -ENOMEM;
498
499 return ret;
500 }
501
gb_gpio_probe(struct gbphy_device * gbphy_dev,const struct gbphy_device_id * id)502 static int gb_gpio_probe(struct gbphy_device *gbphy_dev,
503 const struct gbphy_device_id *id)
504 {
505 struct gb_connection *connection;
506 struct gb_gpio_controller *ggc;
507 struct gpio_chip *gpio;
508 struct gpio_irq_chip *girq;
509 struct irq_chip *irqc;
510 int ret;
511
512 ggc = kzalloc(sizeof(*ggc), GFP_KERNEL);
513 if (!ggc)
514 return -ENOMEM;
515
516 connection =
517 gb_connection_create(gbphy_dev->bundle,
518 le16_to_cpu(gbphy_dev->cport_desc->id),
519 gb_gpio_request_handler);
520 if (IS_ERR(connection)) {
521 ret = PTR_ERR(connection);
522 goto exit_ggc_free;
523 }
524
525 ggc->connection = connection;
526 gb_connection_set_data(connection, ggc);
527 ggc->gbphy_dev = gbphy_dev;
528 gb_gbphy_set_data(gbphy_dev, ggc);
529
530 ret = gb_connection_enable_tx(connection);
531 if (ret)
532 goto exit_connection_destroy;
533
534 ret = gb_gpio_controller_setup(ggc);
535 if (ret)
536 goto exit_connection_disable;
537
538 irqc = &ggc->irqc;
539 irqc->irq_mask = gb_gpio_irq_mask;
540 irqc->irq_unmask = gb_gpio_irq_unmask;
541 irqc->irq_set_type = gb_gpio_irq_set_type;
542 irqc->irq_bus_lock = gb_gpio_irq_bus_lock;
543 irqc->irq_bus_sync_unlock = gb_gpio_irq_bus_sync_unlock;
544 irqc->name = "greybus_gpio";
545
546 mutex_init(&ggc->irq_lock);
547
548 gpio = &ggc->chip;
549
550 gpio->label = "greybus_gpio";
551 gpio->parent = &gbphy_dev->dev;
552 gpio->owner = THIS_MODULE;
553
554 gpio->request = gb_gpio_request;
555 gpio->free = gb_gpio_free;
556 gpio->get_direction = gb_gpio_get_direction;
557 gpio->direction_input = gb_gpio_direction_input;
558 gpio->direction_output = gb_gpio_direction_output;
559 gpio->get = gb_gpio_get;
560 gpio->set_rv = gb_gpio_set;
561 gpio->set_config = gb_gpio_set_config;
562 gpio->base = -1; /* Allocate base dynamically */
563 gpio->ngpio = ggc->line_max + 1;
564 gpio->can_sleep = true;
565
566 girq = &gpio->irq;
567 girq->chip = irqc;
568 /* The event comes from the outside so no parent handler */
569 girq->parent_handler = NULL;
570 girq->num_parents = 0;
571 girq->parents = NULL;
572 girq->default_type = IRQ_TYPE_NONE;
573 girq->handler = handle_level_irq;
574
575 ret = gb_connection_enable(connection);
576 if (ret)
577 goto exit_line_free;
578
579 ret = gpiochip_add_data(gpio, ggc);
580 if (ret) {
581 dev_err(&gbphy_dev->dev, "failed to add gpio chip: %d\n", ret);
582 goto exit_line_free;
583 }
584
585 gbphy_runtime_put_autosuspend(gbphy_dev);
586 return 0;
587
588 exit_line_free:
589 kfree(ggc->lines);
590 exit_connection_disable:
591 gb_connection_disable(connection);
592 exit_connection_destroy:
593 gb_connection_destroy(connection);
594 exit_ggc_free:
595 kfree(ggc);
596 return ret;
597 }
598
gb_gpio_remove(struct gbphy_device * gbphy_dev)599 static void gb_gpio_remove(struct gbphy_device *gbphy_dev)
600 {
601 struct gb_gpio_controller *ggc = gb_gbphy_get_data(gbphy_dev);
602 struct gb_connection *connection = ggc->connection;
603 int ret;
604
605 ret = gbphy_runtime_get_sync(gbphy_dev);
606 if (ret)
607 gbphy_runtime_get_noresume(gbphy_dev);
608
609 gb_connection_disable_rx(connection);
610 gpiochip_remove(&ggc->chip);
611 gb_connection_disable(connection);
612 gb_connection_destroy(connection);
613 kfree(ggc->lines);
614 kfree(ggc);
615 }
616
617 static const struct gbphy_device_id gb_gpio_id_table[] = {
618 { GBPHY_PROTOCOL(GREYBUS_PROTOCOL_GPIO) },
619 { },
620 };
621 MODULE_DEVICE_TABLE(gbphy, gb_gpio_id_table);
622
623 static struct gbphy_driver gpio_driver = {
624 .name = "gpio",
625 .probe = gb_gpio_probe,
626 .remove = gb_gpio_remove,
627 .id_table = gb_gpio_id_table,
628 };
629
630 module_gbphy_driver(gpio_driver);
631 MODULE_DESCRIPTION("GPIO Greybus driver");
632 MODULE_LICENSE("GPL v2");
633