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