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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
20struct gb_gpio_line {
21
22
23 u8 active: 1,
24 direction: 1,
25 value: 1;
26 u16 debounce_usec;
27
28 u8 irq_type;
29 bool irq_type_pending;
30 bool masked;
31 bool masked_pending;
32};
33
34struct gb_gpio_controller {
35 struct gbphy_device *gbphy_dev;
36 struct gb_connection *connection;
37 u8 line_max;
38 struct gb_gpio_line *lines;
39
40 struct gpio_chip chip;
41 struct irq_chip irqc;
42 struct mutex irq_lock;
43};
44#define gpio_chip_to_gb_gpio_controller(chip) \
45 container_of(chip, struct gb_gpio_controller, chip)
46#define irq_data_to_gpio_chip(d) (d->domain->host_data)
47
48static int gb_gpio_line_count_operation(struct gb_gpio_controller *ggc)
49{
50 struct gb_gpio_line_count_response response;
51 int ret;
52
53 ret = gb_operation_sync(ggc->connection, GB_GPIO_TYPE_LINE_COUNT,
54 NULL, 0, &response, sizeof(response));
55 if (!ret)
56 ggc->line_max = response.count;
57 return ret;
58}
59
60static int gb_gpio_activate_operation(struct gb_gpio_controller *ggc, u8 which)
61{
62 struct gb_gpio_activate_request request;
63 struct gbphy_device *gbphy_dev = ggc->gbphy_dev;
64 int ret;
65
66 ret = gbphy_runtime_get_sync(gbphy_dev);
67 if (ret)
68 return ret;
69
70 request.which = which;
71 ret = gb_operation_sync(ggc->connection, GB_GPIO_TYPE_ACTIVATE,
72 &request, sizeof(request), NULL, 0);
73 if (ret) {
74 gbphy_runtime_put_autosuspend(gbphy_dev);
75 return ret;
76 }
77
78 ggc->lines[which].active = true;
79
80 return 0;
81}
82
83static void gb_gpio_deactivate_operation(struct gb_gpio_controller *ggc,
84 u8 which)
85{
86 struct gbphy_device *gbphy_dev = ggc->gbphy_dev;
87 struct device *dev = &gbphy_dev->dev;
88 struct gb_gpio_deactivate_request request;
89 int ret;
90
91 request.which = which;
92 ret = gb_operation_sync(ggc->connection, GB_GPIO_TYPE_DEACTIVATE,
93 &request, sizeof(request), NULL, 0);
94 if (ret) {
95 dev_err(dev, "failed to deactivate gpio %u\n", which);
96 goto out_pm_put;
97 }
98
99 ggc->lines[which].active = false;
100
101out_pm_put:
102 gbphy_runtime_put_autosuspend(gbphy_dev);
103}
104
105static int gb_gpio_get_direction_operation(struct gb_gpio_controller *ggc,
106 u8 which)
107{
108 struct device *dev = &ggc->gbphy_dev->dev;
109 struct gb_gpio_get_direction_request request;
110 struct gb_gpio_get_direction_response response;
111 int ret;
112 u8 direction;
113
114 request.which = which;
115 ret = gb_operation_sync(ggc->connection, GB_GPIO_TYPE_GET_DIRECTION,
116 &request, sizeof(request),
117 &response, sizeof(response));
118 if (ret)
119 return ret;
120
121 direction = response.direction;
122 if (direction && direction != 1) {
123 dev_warn(dev, "gpio %u direction was %u (should be 0 or 1)\n",
124 which, direction);
125 }
126 ggc->lines[which].direction = direction ? 1 : 0;
127 return 0;
128}
129
130static int gb_gpio_direction_in_operation(struct gb_gpio_controller *ggc,
131 u8 which)
132{
133 struct gb_gpio_direction_in_request request;
134 int ret;
135
136 request.which = which;
137 ret = gb_operation_sync(ggc->connection, GB_GPIO_TYPE_DIRECTION_IN,
138 &request, sizeof(request), NULL, 0);
139 if (!ret)
140 ggc->lines[which].direction = 1;
141 return ret;
142}
143
144static int gb_gpio_direction_out_operation(struct gb_gpio_controller *ggc,
145 u8 which, bool value_high)
146{
147 struct gb_gpio_direction_out_request request;
148 int ret;
149
150 request.which = which;
151 request.value = value_high ? 1 : 0;
152 ret = gb_operation_sync(ggc->connection, GB_GPIO_TYPE_DIRECTION_OUT,
153 &request, sizeof(request), NULL, 0);
154 if (!ret)
155 ggc->lines[which].direction = 0;
156 return ret;
157}
158
159static int gb_gpio_get_value_operation(struct gb_gpio_controller *ggc,
160 u8 which)
161{
162 struct device *dev = &ggc->gbphy_dev->dev;
163 struct gb_gpio_get_value_request request;
164 struct gb_gpio_get_value_response response;
165 int ret;
166 u8 value;
167
168 request.which = which;
169 ret = gb_operation_sync(ggc->connection, GB_GPIO_TYPE_GET_VALUE,
170 &request, sizeof(request),
171 &response, sizeof(response));
172 if (ret) {
173 dev_err(dev, "failed to get value of gpio %u\n", which);
174 return ret;
175 }
176
177 value = response.value;
178 if (value && value != 1) {
179 dev_warn(dev, "gpio %u value was %u (should be 0 or 1)\n",
180 which, value);
181 }
182 ggc->lines[which].value = value ? 1 : 0;
183 return 0;
184}
185
186static void gb_gpio_set_value_operation(struct gb_gpio_controller *ggc,
187 u8 which, bool value_high)
188{
189 struct device *dev = &ggc->gbphy_dev->dev;
190 struct gb_gpio_set_value_request request;
191 int ret;
192
193 if (ggc->lines[which].direction == 1) {
194 dev_warn(dev, "refusing to set value of input gpio %u\n",
195 which);
196 return;
197 }
198
199 request.which = which;
200 request.value = value_high ? 1 : 0;
201 ret = gb_operation_sync(ggc->connection, GB_GPIO_TYPE_SET_VALUE,
202 &request, sizeof(request), NULL, 0);
203 if (ret) {
204 dev_err(dev, "failed to set value of gpio %u\n", which);
205 return;
206 }
207
208 ggc->lines[which].value = request.value;
209}
210
211static int gb_gpio_set_debounce_operation(struct gb_gpio_controller *ggc,
212 u8 which, u16 debounce_usec)
213{
214 struct gb_gpio_set_debounce_request request;
215 int ret;
216
217 request.which = which;
218 request.usec = cpu_to_le16(debounce_usec);
219 ret = gb_operation_sync(ggc->connection, GB_GPIO_TYPE_SET_DEBOUNCE,
220 &request, sizeof(request), NULL, 0);
221 if (!ret)
222 ggc->lines[which].debounce_usec = debounce_usec;
223 return ret;
224}
225
226static void _gb_gpio_irq_mask(struct gb_gpio_controller *ggc, u8 hwirq)
227{
228 struct device *dev = &ggc->gbphy_dev->dev;
229 struct gb_gpio_irq_mask_request request;
230 int ret;
231
232 request.which = hwirq;
233 ret = gb_operation_sync(ggc->connection,
234 GB_GPIO_TYPE_IRQ_MASK,
235 &request, sizeof(request), NULL, 0);
236 if (ret)
237 dev_err(dev, "failed to mask irq: %d\n", ret);
238}
239
240static void _gb_gpio_irq_unmask(struct gb_gpio_controller *ggc, u8 hwirq)
241{
242 struct device *dev = &ggc->gbphy_dev->dev;
243 struct gb_gpio_irq_unmask_request request;
244 int ret;
245
246 request.which = hwirq;
247 ret = gb_operation_sync(ggc->connection,
248 GB_GPIO_TYPE_IRQ_UNMASK,
249 &request, sizeof(request), NULL, 0);
250 if (ret)
251 dev_err(dev, "failed to unmask irq: %d\n", ret);
252}
253
254static void _gb_gpio_irq_set_type(struct gb_gpio_controller *ggc,
255 u8 hwirq, u8 type)
256{
257 struct device *dev = &ggc->gbphy_dev->dev;
258 struct gb_gpio_irq_type_request request;
259 int ret;
260
261 request.which = hwirq;
262 request.type = type;
263
264 ret = gb_operation_sync(ggc->connection,
265 GB_GPIO_TYPE_IRQ_TYPE,
266 &request, sizeof(request), NULL, 0);
267 if (ret)
268 dev_err(dev, "failed to set irq type: %d\n", ret);
269}
270
271static void gb_gpio_irq_mask(struct irq_data *d)
272{
273 struct gpio_chip *chip = irq_data_to_gpio_chip(d);
274 struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
275 struct gb_gpio_line *line = &ggc->lines[d->hwirq];
276
277 line->masked = true;
278 line->masked_pending = true;
279}
280
281static void gb_gpio_irq_unmask(struct irq_data *d)
282{
283 struct gpio_chip *chip = irq_data_to_gpio_chip(d);
284 struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
285 struct gb_gpio_line *line = &ggc->lines[d->hwirq];
286
287 line->masked = false;
288 line->masked_pending = true;
289}
290
291static int gb_gpio_irq_set_type(struct irq_data *d, unsigned int type)
292{
293 struct gpio_chip *chip = irq_data_to_gpio_chip(d);
294 struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
295 struct gb_gpio_line *line = &ggc->lines[d->hwirq];
296 struct device *dev = &ggc->gbphy_dev->dev;
297 u8 irq_type;
298
299 switch (type) {
300 case IRQ_TYPE_NONE:
301 irq_type = GB_GPIO_IRQ_TYPE_NONE;
302 break;
303 case IRQ_TYPE_EDGE_RISING:
304 irq_type = GB_GPIO_IRQ_TYPE_EDGE_RISING;
305 break;
306 case IRQ_TYPE_EDGE_FALLING:
307 irq_type = GB_GPIO_IRQ_TYPE_EDGE_FALLING;
308 break;
309 case IRQ_TYPE_EDGE_BOTH:
310 irq_type = GB_GPIO_IRQ_TYPE_EDGE_BOTH;
311 break;
312 case IRQ_TYPE_LEVEL_LOW:
313 irq_type = GB_GPIO_IRQ_TYPE_LEVEL_LOW;
314 break;
315 case IRQ_TYPE_LEVEL_HIGH:
316 irq_type = GB_GPIO_IRQ_TYPE_LEVEL_HIGH;
317 break;
318 default:
319 dev_err(dev, "unsupported irq type: %u\n", type);
320 return -EINVAL;
321 }
322
323 line->irq_type = irq_type;
324 line->irq_type_pending = true;
325
326 return 0;
327}
328
329static void gb_gpio_irq_bus_lock(struct irq_data *d)
330{
331 struct gpio_chip *chip = irq_data_to_gpio_chip(d);
332 struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
333
334 mutex_lock(&ggc->irq_lock);
335}
336
337static void gb_gpio_irq_bus_sync_unlock(struct irq_data *d)
338{
339 struct gpio_chip *chip = irq_data_to_gpio_chip(d);
340 struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
341 struct gb_gpio_line *line = &ggc->lines[d->hwirq];
342
343 if (line->irq_type_pending) {
344 _gb_gpio_irq_set_type(ggc, d->hwirq, line->irq_type);
345 line->irq_type_pending = false;
346 }
347
348 if (line->masked_pending) {
349 if (line->masked)
350 _gb_gpio_irq_mask(ggc, d->hwirq);
351 else
352 _gb_gpio_irq_unmask(ggc, d->hwirq);
353 line->masked_pending = false;
354 }
355
356 mutex_unlock(&ggc->irq_lock);
357}
358
359static int gb_gpio_request_handler(struct gb_operation *op)
360{
361 struct gb_connection *connection = op->connection;
362 struct gb_gpio_controller *ggc = gb_connection_get_data(connection);
363 struct device *dev = &ggc->gbphy_dev->dev;
364 struct gb_message *request;
365 struct gb_gpio_irq_event_request *event;
366 u8 type = op->type;
367 int irq, ret;
368
369 if (type != GB_GPIO_TYPE_IRQ_EVENT) {
370 dev_err(dev, "unsupported unsolicited request: %u\n", type);
371 return -EINVAL;
372 }
373
374 request = op->request;
375
376 if (request->payload_size < sizeof(*event)) {
377 dev_err(dev, "short event received (%zu < %zu)\n",
378 request->payload_size, sizeof(*event));
379 return -EINVAL;
380 }
381
382 event = request->payload;
383 if (event->which > ggc->line_max) {
384 dev_err(dev, "invalid hw irq: %d\n", event->which);
385 return -EINVAL;
386 }
387
388 irq = irq_find_mapping(ggc->chip.irq.domain, event->which);
389 if (!irq) {
390 dev_err(dev, "failed to find IRQ\n");
391 return -EINVAL;
392 }
393
394 ret = generic_handle_irq_safe(irq);
395 if (ret)
396 dev_err(dev, "failed to invoke irq handler\n");
397
398 return ret;
399}
400
401static int gb_gpio_request(struct gpio_chip *chip, unsigned int offset)
402{
403 struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
404
405 return gb_gpio_activate_operation(ggc, (u8)offset);
406}
407
408static void gb_gpio_free(struct gpio_chip *chip, unsigned int offset)
409{
410 struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
411
412 gb_gpio_deactivate_operation(ggc, (u8)offset);
413}
414
415static int gb_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
416{
417 struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
418 u8 which;
419 int ret;
420
421 which = (u8)offset;
422 ret = gb_gpio_get_direction_operation(ggc, which);
423 if (ret)
424 return ret;
425
426 return ggc->lines[which].direction ? 1 : 0;
427}
428
429static int gb_gpio_direction_input(struct gpio_chip *chip, unsigned int offset)
430{
431 struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
432
433 return gb_gpio_direction_in_operation(ggc, (u8)offset);
434}
435
436static int gb_gpio_direction_output(struct gpio_chip *chip, unsigned int offset,
437 int value)
438{
439 struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
440
441 return gb_gpio_direction_out_operation(ggc, (u8)offset, !!value);
442}
443
444static int gb_gpio_get(struct gpio_chip *chip, unsigned int offset)
445{
446 struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
447 u8 which;
448 int ret;
449
450 which = (u8)offset;
451 ret = gb_gpio_get_value_operation(ggc, which);
452 if (ret)
453 return ret;
454
455 return ggc->lines[which].value;
456}
457
458static void gb_gpio_set(struct gpio_chip *chip, unsigned int offset, int value)
459{
460 struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
461
462 gb_gpio_set_value_operation(ggc, (u8)offset, !!value);
463}
464
465static int gb_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
466 unsigned long config)
467{
468 struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
469 u32 debounce;
470
471 if (pinconf_to_config_param(config) != PIN_CONFIG_INPUT_DEBOUNCE)
472 return -ENOTSUPP;
473
474 debounce = pinconf_to_config_argument(config);
475 if (debounce > U16_MAX)
476 return -EINVAL;
477
478 return gb_gpio_set_debounce_operation(ggc, (u8)offset, (u16)debounce);
479}
480
481static int gb_gpio_controller_setup(struct gb_gpio_controller *ggc)
482{
483 int ret;
484
485
486 ret = gb_gpio_line_count_operation(ggc);
487 if (ret)
488 return ret;
489
490 ggc->lines = kcalloc(ggc->line_max + 1, sizeof(*ggc->lines),
491 GFP_KERNEL);
492 if (!ggc->lines)
493 return -ENOMEM;
494
495 return ret;
496}
497
498static int gb_gpio_probe(struct gbphy_device *gbphy_dev,
499 const struct gbphy_device_id *id)
500{
501 struct gb_connection *connection;
502 struct gb_gpio_controller *ggc;
503 struct gpio_chip *gpio;
504 struct gpio_irq_chip *girq;
505 struct irq_chip *irqc;
506 int ret;
507
508 ggc = kzalloc(sizeof(*ggc), GFP_KERNEL);
509 if (!ggc)
510 return -ENOMEM;
511
512 connection =
513 gb_connection_create(gbphy_dev->bundle,
514 le16_to_cpu(gbphy_dev->cport_desc->id),
515 gb_gpio_request_handler);
516 if (IS_ERR(connection)) {
517 ret = PTR_ERR(connection);
518 goto exit_ggc_free;
519 }
520
521 ggc->connection = connection;
522 gb_connection_set_data(connection, ggc);
523 ggc->gbphy_dev = gbphy_dev;
524 gb_gbphy_set_data(gbphy_dev, ggc);
525
526 ret = gb_connection_enable_tx(connection);
527 if (ret)
528 goto exit_connection_destroy;
529
530 ret = gb_gpio_controller_setup(ggc);
531 if (ret)
532 goto exit_connection_disable;
533
534 irqc = &ggc->irqc;
535 irqc->irq_mask = gb_gpio_irq_mask;
536 irqc->irq_unmask = gb_gpio_irq_unmask;
537 irqc->irq_set_type = gb_gpio_irq_set_type;
538 irqc->irq_bus_lock = gb_gpio_irq_bus_lock;
539 irqc->irq_bus_sync_unlock = gb_gpio_irq_bus_sync_unlock;
540 irqc->name = "greybus_gpio";
541
542 mutex_init(&ggc->irq_lock);
543
544 gpio = &ggc->chip;
545
546 gpio->label = "greybus_gpio";
547 gpio->parent = &gbphy_dev->dev;
548 gpio->owner = THIS_MODULE;
549
550 gpio->request = gb_gpio_request;
551 gpio->free = gb_gpio_free;
552 gpio->get_direction = gb_gpio_get_direction;
553 gpio->direction_input = gb_gpio_direction_input;
554 gpio->direction_output = gb_gpio_direction_output;
555 gpio->get = gb_gpio_get;
556 gpio->set = gb_gpio_set;
557 gpio->set_config = gb_gpio_set_config;
558 gpio->base = -1;
559 gpio->ngpio = ggc->line_max + 1;
560 gpio->can_sleep = true;
561
562 girq = &gpio->irq;
563 girq->chip = irqc;
564
565 girq->parent_handler = NULL;
566 girq->num_parents = 0;
567 girq->parents = NULL;
568 girq->default_type = IRQ_TYPE_NONE;
569 girq->handler = handle_level_irq;
570
571 ret = gb_connection_enable(connection);
572 if (ret)
573 goto exit_line_free;
574
575 ret = gpiochip_add(gpio);
576 if (ret) {
577 dev_err(&gbphy_dev->dev, "failed to add gpio chip: %d\n", ret);
578 goto exit_line_free;
579 }
580
581 gbphy_runtime_put_autosuspend(gbphy_dev);
582 return 0;
583
584exit_line_free:
585 kfree(ggc->lines);
586exit_connection_disable:
587 gb_connection_disable(connection);
588exit_connection_destroy:
589 gb_connection_destroy(connection);
590exit_ggc_free:
591 kfree(ggc);
592 return ret;
593}
594
595static void gb_gpio_remove(struct gbphy_device *gbphy_dev)
596{
597 struct gb_gpio_controller *ggc = gb_gbphy_get_data(gbphy_dev);
598 struct gb_connection *connection = ggc->connection;
599 int ret;
600
601 ret = gbphy_runtime_get_sync(gbphy_dev);
602 if (ret)
603 gbphy_runtime_get_noresume(gbphy_dev);
604
605 gb_connection_disable_rx(connection);
606 gpiochip_remove(&ggc->chip);
607 gb_connection_disable(connection);
608 gb_connection_destroy(connection);
609 kfree(ggc->lines);
610 kfree(ggc);
611}
612
613static const struct gbphy_device_id gb_gpio_id_table[] = {
614 { GBPHY_PROTOCOL(GREYBUS_PROTOCOL_GPIO) },
615 { },
616};
617MODULE_DEVICE_TABLE(gbphy, gb_gpio_id_table);
618
619static struct gbphy_driver gpio_driver = {
620 .name = "gpio",
621 .probe = gb_gpio_probe,
622 .remove = gb_gpio_remove,
623 .id_table = gb_gpio_id_table,
624};
625
626module_gbphy_driver(gpio_driver);
627MODULE_LICENSE("GPL v2");
628
