1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * HSI core.
4 *
5 * Copyright (C) 2010 Nokia Corporation. All rights reserved.
6 *
7 * Contact: Carlos Chinea <carlos.chinea@nokia.com>
8 */
9 #include <linux/hsi/hsi.h>
10 #include <linux/compiler.h>
11 #include <linux/list.h>
12 #include <linux/kobject.h>
13 #include <linux/slab.h>
14 #include <linux/string.h>
15 #include <linux/notifier.h>
16 #include <linux/of.h>
17 #include <linux/of_device.h>
18 #include "hsi_core.h"
19
modalias_show(struct device * dev,struct device_attribute * a __maybe_unused,char * buf)20 static ssize_t modalias_show(struct device *dev,
21 struct device_attribute *a __maybe_unused, char *buf)
22 {
23 return sprintf(buf, "hsi:%s\n", dev_name(dev));
24 }
25 static DEVICE_ATTR_RO(modalias);
26
27 static struct attribute *hsi_bus_dev_attrs[] = {
28 &dev_attr_modalias.attr,
29 NULL,
30 };
31 ATTRIBUTE_GROUPS(hsi_bus_dev);
32
hsi_bus_uevent(struct device * dev,struct kobj_uevent_env * env)33 static int hsi_bus_uevent(struct device *dev, struct kobj_uevent_env *env)
34 {
35 add_uevent_var(env, "MODALIAS=hsi:%s", dev_name(dev));
36
37 return 0;
38 }
39
hsi_bus_match(struct device * dev,struct device_driver * driver)40 static int hsi_bus_match(struct device *dev, struct device_driver *driver)
41 {
42 if (of_driver_match_device(dev, driver))
43 return true;
44
45 if (strcmp(dev_name(dev), driver->name) == 0)
46 return true;
47
48 return false;
49 }
50
51 static struct bus_type hsi_bus_type = {
52 .name = "hsi",
53 .dev_groups = hsi_bus_dev_groups,
54 .match = hsi_bus_match,
55 .uevent = hsi_bus_uevent,
56 };
57
hsi_client_release(struct device * dev)58 static void hsi_client_release(struct device *dev)
59 {
60 struct hsi_client *cl = to_hsi_client(dev);
61
62 kfree(cl->tx_cfg.channels);
63 kfree(cl->rx_cfg.channels);
64 kfree(cl);
65 }
66
hsi_new_client(struct hsi_port * port,struct hsi_board_info * info)67 struct hsi_client *hsi_new_client(struct hsi_port *port,
68 struct hsi_board_info *info)
69 {
70 struct hsi_client *cl;
71 size_t size;
72
73 cl = kzalloc(sizeof(*cl), GFP_KERNEL);
74 if (!cl)
75 goto err;
76
77 cl->tx_cfg = info->tx_cfg;
78 if (cl->tx_cfg.channels) {
79 size = cl->tx_cfg.num_channels * sizeof(*cl->tx_cfg.channels);
80 cl->tx_cfg.channels = kmemdup(info->tx_cfg.channels, size,
81 GFP_KERNEL);
82 if (!cl->tx_cfg.channels)
83 goto err_tx;
84 }
85
86 cl->rx_cfg = info->rx_cfg;
87 if (cl->rx_cfg.channels) {
88 size = cl->rx_cfg.num_channels * sizeof(*cl->rx_cfg.channels);
89 cl->rx_cfg.channels = kmemdup(info->rx_cfg.channels, size,
90 GFP_KERNEL);
91 if (!cl->rx_cfg.channels)
92 goto err_rx;
93 }
94
95 cl->device.bus = &hsi_bus_type;
96 cl->device.parent = &port->device;
97 cl->device.release = hsi_client_release;
98 dev_set_name(&cl->device, "%s", info->name);
99 cl->device.platform_data = info->platform_data;
100 if (info->archdata)
101 cl->device.archdata = *info->archdata;
102 if (device_register(&cl->device) < 0) {
103 pr_err("hsi: failed to register client: %s\n", info->name);
104 put_device(&cl->device);
105 goto err;
106 }
107
108 return cl;
109 err_rx:
110 kfree(cl->tx_cfg.channels);
111 err_tx:
112 kfree(cl);
113 err:
114 return NULL;
115 }
116 EXPORT_SYMBOL_GPL(hsi_new_client);
117
hsi_scan_board_info(struct hsi_controller * hsi)118 static void hsi_scan_board_info(struct hsi_controller *hsi)
119 {
120 struct hsi_cl_info *cl_info;
121 struct hsi_port *p;
122
123 list_for_each_entry(cl_info, &hsi_board_list, list)
124 if (cl_info->info.hsi_id == hsi->id) {
125 p = hsi_find_port_num(hsi, cl_info->info.port);
126 if (!p)
127 continue;
128 hsi_new_client(p, &cl_info->info);
129 }
130 }
131
132 #ifdef CONFIG_OF
133 static struct hsi_board_info hsi_char_dev_info = {
134 .name = "hsi_char",
135 };
136
hsi_of_property_parse_mode(struct device_node * client,char * name,unsigned int * result)137 static int hsi_of_property_parse_mode(struct device_node *client, char *name,
138 unsigned int *result)
139 {
140 const char *mode;
141 int err;
142
143 err = of_property_read_string(client, name, &mode);
144 if (err < 0)
145 return err;
146
147 if (strcmp(mode, "stream") == 0)
148 *result = HSI_MODE_STREAM;
149 else if (strcmp(mode, "frame") == 0)
150 *result = HSI_MODE_FRAME;
151 else
152 return -EINVAL;
153
154 return 0;
155 }
156
hsi_of_property_parse_flow(struct device_node * client,char * name,unsigned int * result)157 static int hsi_of_property_parse_flow(struct device_node *client, char *name,
158 unsigned int *result)
159 {
160 const char *flow;
161 int err;
162
163 err = of_property_read_string(client, name, &flow);
164 if (err < 0)
165 return err;
166
167 if (strcmp(flow, "synchronized") == 0)
168 *result = HSI_FLOW_SYNC;
169 else if (strcmp(flow, "pipeline") == 0)
170 *result = HSI_FLOW_PIPE;
171 else
172 return -EINVAL;
173
174 return 0;
175 }
176
hsi_of_property_parse_arb_mode(struct device_node * client,char * name,unsigned int * result)177 static int hsi_of_property_parse_arb_mode(struct device_node *client,
178 char *name, unsigned int *result)
179 {
180 const char *arb_mode;
181 int err;
182
183 err = of_property_read_string(client, name, &arb_mode);
184 if (err < 0)
185 return err;
186
187 if (strcmp(arb_mode, "round-robin") == 0)
188 *result = HSI_ARB_RR;
189 else if (strcmp(arb_mode, "priority") == 0)
190 *result = HSI_ARB_PRIO;
191 else
192 return -EINVAL;
193
194 return 0;
195 }
196
hsi_add_client_from_dt(struct hsi_port * port,struct device_node * client)197 static void hsi_add_client_from_dt(struct hsi_port *port,
198 struct device_node *client)
199 {
200 struct hsi_client *cl;
201 struct hsi_channel channel;
202 struct property *prop;
203 char name[32];
204 int length, cells, err, i, max_chan, mode;
205
206 cl = kzalloc(sizeof(*cl), GFP_KERNEL);
207 if (!cl)
208 return;
209
210 err = of_modalias_node(client, name, sizeof(name));
211 if (err)
212 goto err;
213
214 err = hsi_of_property_parse_mode(client, "hsi-mode", &mode);
215 if (err) {
216 err = hsi_of_property_parse_mode(client, "hsi-rx-mode",
217 &cl->rx_cfg.mode);
218 if (err)
219 goto err;
220
221 err = hsi_of_property_parse_mode(client, "hsi-tx-mode",
222 &cl->tx_cfg.mode);
223 if (err)
224 goto err;
225 } else {
226 cl->rx_cfg.mode = mode;
227 cl->tx_cfg.mode = mode;
228 }
229
230 err = of_property_read_u32(client, "hsi-speed-kbps",
231 &cl->tx_cfg.speed);
232 if (err)
233 goto err;
234 cl->rx_cfg.speed = cl->tx_cfg.speed;
235
236 err = hsi_of_property_parse_flow(client, "hsi-flow",
237 &cl->rx_cfg.flow);
238 if (err)
239 goto err;
240
241 err = hsi_of_property_parse_arb_mode(client, "hsi-arb-mode",
242 &cl->rx_cfg.arb_mode);
243 if (err)
244 goto err;
245
246 prop = of_find_property(client, "hsi-channel-ids", &length);
247 if (!prop) {
248 err = -EINVAL;
249 goto err;
250 }
251
252 cells = length / sizeof(u32);
253
254 cl->rx_cfg.num_channels = cells;
255 cl->tx_cfg.num_channels = cells;
256 cl->rx_cfg.channels = kcalloc(cells, sizeof(channel), GFP_KERNEL);
257 if (!cl->rx_cfg.channels) {
258 err = -ENOMEM;
259 goto err;
260 }
261
262 cl->tx_cfg.channels = kcalloc(cells, sizeof(channel), GFP_KERNEL);
263 if (!cl->tx_cfg.channels) {
264 err = -ENOMEM;
265 goto err2;
266 }
267
268 max_chan = 0;
269 for (i = 0; i < cells; i++) {
270 err = of_property_read_u32_index(client, "hsi-channel-ids", i,
271 &channel.id);
272 if (err)
273 goto err3;
274
275 err = of_property_read_string_index(client, "hsi-channel-names",
276 i, &channel.name);
277 if (err)
278 channel.name = NULL;
279
280 if (channel.id > max_chan)
281 max_chan = channel.id;
282
283 cl->rx_cfg.channels[i] = channel;
284 cl->tx_cfg.channels[i] = channel;
285 }
286
287 cl->rx_cfg.num_hw_channels = max_chan + 1;
288 cl->tx_cfg.num_hw_channels = max_chan + 1;
289
290 cl->device.bus = &hsi_bus_type;
291 cl->device.parent = &port->device;
292 cl->device.release = hsi_client_release;
293 cl->device.of_node = client;
294
295 dev_set_name(&cl->device, "%s", name);
296 if (device_register(&cl->device) < 0) {
297 pr_err("hsi: failed to register client: %s\n", name);
298 put_device(&cl->device);
299 }
300
301 return;
302
303 err3:
304 kfree(cl->tx_cfg.channels);
305 err2:
306 kfree(cl->rx_cfg.channels);
307 err:
308 kfree(cl);
309 pr_err("hsi client: missing or incorrect of property: err=%d\n", err);
310 }
311
hsi_add_clients_from_dt(struct hsi_port * port,struct device_node * clients)312 void hsi_add_clients_from_dt(struct hsi_port *port, struct device_node *clients)
313 {
314 struct device_node *child;
315
316 /* register hsi-char device */
317 hsi_new_client(port, &hsi_char_dev_info);
318
319 for_each_available_child_of_node(clients, child)
320 hsi_add_client_from_dt(port, child);
321 }
322 EXPORT_SYMBOL_GPL(hsi_add_clients_from_dt);
323 #endif
324
hsi_remove_client(struct device * dev,void * data __maybe_unused)325 int hsi_remove_client(struct device *dev, void *data __maybe_unused)
326 {
327 device_unregister(dev);
328
329 return 0;
330 }
331 EXPORT_SYMBOL_GPL(hsi_remove_client);
332
hsi_remove_port(struct device * dev,void * data __maybe_unused)333 static int hsi_remove_port(struct device *dev, void *data __maybe_unused)
334 {
335 device_for_each_child(dev, NULL, hsi_remove_client);
336 device_unregister(dev);
337
338 return 0;
339 }
340
hsi_controller_release(struct device * dev)341 static void hsi_controller_release(struct device *dev)
342 {
343 struct hsi_controller *hsi = to_hsi_controller(dev);
344
345 kfree(hsi->port);
346 kfree(hsi);
347 }
348
hsi_port_release(struct device * dev)349 static void hsi_port_release(struct device *dev)
350 {
351 kfree(to_hsi_port(dev));
352 }
353
354 /**
355 * hsi_unregister_port - Unregister an HSI port
356 * @port: The HSI port to unregister
357 */
hsi_port_unregister_clients(struct hsi_port * port)358 void hsi_port_unregister_clients(struct hsi_port *port)
359 {
360 device_for_each_child(&port->device, NULL, hsi_remove_client);
361 }
362 EXPORT_SYMBOL_GPL(hsi_port_unregister_clients);
363
364 /**
365 * hsi_unregister_controller - Unregister an HSI controller
366 * @hsi: The HSI controller to register
367 */
hsi_unregister_controller(struct hsi_controller * hsi)368 void hsi_unregister_controller(struct hsi_controller *hsi)
369 {
370 device_for_each_child(&hsi->device, NULL, hsi_remove_port);
371 device_unregister(&hsi->device);
372 }
373 EXPORT_SYMBOL_GPL(hsi_unregister_controller);
374
375 /**
376 * hsi_register_controller - Register an HSI controller and its ports
377 * @hsi: The HSI controller to register
378 *
379 * Returns -errno on failure, 0 on success.
380 */
hsi_register_controller(struct hsi_controller * hsi)381 int hsi_register_controller(struct hsi_controller *hsi)
382 {
383 unsigned int i;
384 int err;
385
386 err = device_add(&hsi->device);
387 if (err < 0)
388 return err;
389 for (i = 0; i < hsi->num_ports; i++) {
390 hsi->port[i]->device.parent = &hsi->device;
391 err = device_add(&hsi->port[i]->device);
392 if (err < 0)
393 goto out;
394 }
395 /* Populate HSI bus with HSI clients */
396 hsi_scan_board_info(hsi);
397
398 return 0;
399 out:
400 while (i-- > 0)
401 device_del(&hsi->port[i]->device);
402 device_del(&hsi->device);
403
404 return err;
405 }
406 EXPORT_SYMBOL_GPL(hsi_register_controller);
407
408 /**
409 * hsi_register_client_driver - Register an HSI client to the HSI bus
410 * @drv: HSI client driver to register
411 *
412 * Returns -errno on failure, 0 on success.
413 */
hsi_register_client_driver(struct hsi_client_driver * drv)414 int hsi_register_client_driver(struct hsi_client_driver *drv)
415 {
416 drv->driver.bus = &hsi_bus_type;
417
418 return driver_register(&drv->driver);
419 }
420 EXPORT_SYMBOL_GPL(hsi_register_client_driver);
421
hsi_dummy_msg(struct hsi_msg * msg __maybe_unused)422 static inline int hsi_dummy_msg(struct hsi_msg *msg __maybe_unused)
423 {
424 return 0;
425 }
426
hsi_dummy_cl(struct hsi_client * cl __maybe_unused)427 static inline int hsi_dummy_cl(struct hsi_client *cl __maybe_unused)
428 {
429 return 0;
430 }
431
432 /**
433 * hsi_put_controller - Free an HSI controller
434 *
435 * @hsi: Pointer to the HSI controller to freed
436 *
437 * HSI controller drivers should only use this function if they need
438 * to free their allocated hsi_controller structures before a successful
439 * call to hsi_register_controller. Other use is not allowed.
440 */
hsi_put_controller(struct hsi_controller * hsi)441 void hsi_put_controller(struct hsi_controller *hsi)
442 {
443 unsigned int i;
444
445 if (!hsi)
446 return;
447
448 for (i = 0; i < hsi->num_ports; i++)
449 if (hsi->port && hsi->port[i])
450 put_device(&hsi->port[i]->device);
451 put_device(&hsi->device);
452 }
453 EXPORT_SYMBOL_GPL(hsi_put_controller);
454
455 /**
456 * hsi_alloc_controller - Allocate an HSI controller and its ports
457 * @n_ports: Number of ports on the HSI controller
458 * @flags: Kernel allocation flags
459 *
460 * Return NULL on failure or a pointer to an hsi_controller on success.
461 */
hsi_alloc_controller(unsigned int n_ports,gfp_t flags)462 struct hsi_controller *hsi_alloc_controller(unsigned int n_ports, gfp_t flags)
463 {
464 struct hsi_controller *hsi;
465 struct hsi_port **port;
466 unsigned int i;
467
468 if (!n_ports)
469 return NULL;
470
471 hsi = kzalloc(sizeof(*hsi), flags);
472 if (!hsi)
473 return NULL;
474 port = kcalloc(n_ports, sizeof(*port), flags);
475 if (!port) {
476 kfree(hsi);
477 return NULL;
478 }
479 hsi->num_ports = n_ports;
480 hsi->port = port;
481 hsi->device.release = hsi_controller_release;
482 device_initialize(&hsi->device);
483
484 for (i = 0; i < n_ports; i++) {
485 port[i] = kzalloc(sizeof(**port), flags);
486 if (port[i] == NULL)
487 goto out;
488 port[i]->num = i;
489 port[i]->async = hsi_dummy_msg;
490 port[i]->setup = hsi_dummy_cl;
491 port[i]->flush = hsi_dummy_cl;
492 port[i]->start_tx = hsi_dummy_cl;
493 port[i]->stop_tx = hsi_dummy_cl;
494 port[i]->release = hsi_dummy_cl;
495 mutex_init(&port[i]->lock);
496 BLOCKING_INIT_NOTIFIER_HEAD(&port[i]->n_head);
497 dev_set_name(&port[i]->device, "port%d", i);
498 hsi->port[i]->device.release = hsi_port_release;
499 device_initialize(&hsi->port[i]->device);
500 }
501
502 return hsi;
503 out:
504 hsi_put_controller(hsi);
505
506 return NULL;
507 }
508 EXPORT_SYMBOL_GPL(hsi_alloc_controller);
509
510 /**
511 * hsi_free_msg - Free an HSI message
512 * @msg: Pointer to the HSI message
513 *
514 * Client is responsible to free the buffers pointed by the scatterlists.
515 */
hsi_free_msg(struct hsi_msg * msg)516 void hsi_free_msg(struct hsi_msg *msg)
517 {
518 if (!msg)
519 return;
520 sg_free_table(&msg->sgt);
521 kfree(msg);
522 }
523 EXPORT_SYMBOL_GPL(hsi_free_msg);
524
525 /**
526 * hsi_alloc_msg - Allocate an HSI message
527 * @nents: Number of memory entries
528 * @flags: Kernel allocation flags
529 *
530 * nents can be 0. This mainly makes sense for read transfer.
531 * In that case, HSI drivers will call the complete callback when
532 * there is data to be read without consuming it.
533 *
534 * Return NULL on failure or a pointer to an hsi_msg on success.
535 */
hsi_alloc_msg(unsigned int nents,gfp_t flags)536 struct hsi_msg *hsi_alloc_msg(unsigned int nents, gfp_t flags)
537 {
538 struct hsi_msg *msg;
539 int err;
540
541 msg = kzalloc(sizeof(*msg), flags);
542 if (!msg)
543 return NULL;
544
545 if (!nents)
546 return msg;
547
548 err = sg_alloc_table(&msg->sgt, nents, flags);
549 if (unlikely(err)) {
550 kfree(msg);
551 msg = NULL;
552 }
553
554 return msg;
555 }
556 EXPORT_SYMBOL_GPL(hsi_alloc_msg);
557
558 /**
559 * hsi_async - Submit an HSI transfer to the controller
560 * @cl: HSI client sending the transfer
561 * @msg: The HSI transfer passed to controller
562 *
563 * The HSI message must have the channel, ttype, complete and destructor
564 * fields set beforehand. If nents > 0 then the client has to initialize
565 * also the scatterlists to point to the buffers to write to or read from.
566 *
567 * HSI controllers relay on pre-allocated buffers from their clients and they
568 * do not allocate buffers on their own.
569 *
570 * Once the HSI message transfer finishes, the HSI controller calls the
571 * complete callback with the status and actual_len fields of the HSI message
572 * updated. The complete callback can be called before returning from
573 * hsi_async.
574 *
575 * Returns -errno on failure or 0 on success
576 */
hsi_async(struct hsi_client * cl,struct hsi_msg * msg)577 int hsi_async(struct hsi_client *cl, struct hsi_msg *msg)
578 {
579 struct hsi_port *port = hsi_get_port(cl);
580
581 if (!hsi_port_claimed(cl))
582 return -EACCES;
583
584 WARN_ON_ONCE(!msg->destructor || !msg->complete);
585 msg->cl = cl;
586
587 return port->async(msg);
588 }
589 EXPORT_SYMBOL_GPL(hsi_async);
590
591 /**
592 * hsi_claim_port - Claim the HSI client's port
593 * @cl: HSI client that wants to claim its port
594 * @share: Flag to indicate if the client wants to share the port or not.
595 *
596 * Returns -errno on failure, 0 on success.
597 */
hsi_claim_port(struct hsi_client * cl,unsigned int share)598 int hsi_claim_port(struct hsi_client *cl, unsigned int share)
599 {
600 struct hsi_port *port = hsi_get_port(cl);
601 int err = 0;
602
603 mutex_lock(&port->lock);
604 if ((port->claimed) && (!port->shared || !share)) {
605 err = -EBUSY;
606 goto out;
607 }
608 if (!try_module_get(to_hsi_controller(port->device.parent)->owner)) {
609 err = -ENODEV;
610 goto out;
611 }
612 port->claimed++;
613 port->shared = !!share;
614 cl->pclaimed = 1;
615 out:
616 mutex_unlock(&port->lock);
617
618 return err;
619 }
620 EXPORT_SYMBOL_GPL(hsi_claim_port);
621
622 /**
623 * hsi_release_port - Release the HSI client's port
624 * @cl: HSI client which previously claimed its port
625 */
hsi_release_port(struct hsi_client * cl)626 void hsi_release_port(struct hsi_client *cl)
627 {
628 struct hsi_port *port = hsi_get_port(cl);
629
630 mutex_lock(&port->lock);
631 /* Allow HW driver to do some cleanup */
632 port->release(cl);
633 if (cl->pclaimed)
634 port->claimed--;
635 BUG_ON(port->claimed < 0);
636 cl->pclaimed = 0;
637 if (!port->claimed)
638 port->shared = 0;
639 module_put(to_hsi_controller(port->device.parent)->owner);
640 mutex_unlock(&port->lock);
641 }
642 EXPORT_SYMBOL_GPL(hsi_release_port);
643
hsi_event_notifier_call(struct notifier_block * nb,unsigned long event,void * data __maybe_unused)644 static int hsi_event_notifier_call(struct notifier_block *nb,
645 unsigned long event, void *data __maybe_unused)
646 {
647 struct hsi_client *cl = container_of(nb, struct hsi_client, nb);
648
649 (*cl->ehandler)(cl, event);
650
651 return 0;
652 }
653
654 /**
655 * hsi_register_port_event - Register a client to receive port events
656 * @cl: HSI client that wants to receive port events
657 * @handler: Event handler callback
658 *
659 * Clients should register a callback to be able to receive
660 * events from the ports. Registration should happen after
661 * claiming the port.
662 * The handler can be called in interrupt context.
663 *
664 * Returns -errno on error, or 0 on success.
665 */
hsi_register_port_event(struct hsi_client * cl,void (* handler)(struct hsi_client *,unsigned long))666 int hsi_register_port_event(struct hsi_client *cl,
667 void (*handler)(struct hsi_client *, unsigned long))
668 {
669 struct hsi_port *port = hsi_get_port(cl);
670
671 if (!handler || cl->ehandler)
672 return -EINVAL;
673 if (!hsi_port_claimed(cl))
674 return -EACCES;
675 cl->ehandler = handler;
676 cl->nb.notifier_call = hsi_event_notifier_call;
677
678 return blocking_notifier_chain_register(&port->n_head, &cl->nb);
679 }
680 EXPORT_SYMBOL_GPL(hsi_register_port_event);
681
682 /**
683 * hsi_unregister_port_event - Stop receiving port events for a client
684 * @cl: HSI client that wants to stop receiving port events
685 *
686 * Clients should call this function before releasing their associated
687 * port.
688 *
689 * Returns -errno on error, or 0 on success.
690 */
hsi_unregister_port_event(struct hsi_client * cl)691 int hsi_unregister_port_event(struct hsi_client *cl)
692 {
693 struct hsi_port *port = hsi_get_port(cl);
694 int err;
695
696 WARN_ON(!hsi_port_claimed(cl));
697
698 err = blocking_notifier_chain_unregister(&port->n_head, &cl->nb);
699 if (!err)
700 cl->ehandler = NULL;
701
702 return err;
703 }
704 EXPORT_SYMBOL_GPL(hsi_unregister_port_event);
705
706 /**
707 * hsi_event - Notifies clients about port events
708 * @port: Port where the event occurred
709 * @event: The event type
710 *
711 * Clients should not be concerned about wake line behavior. However, due
712 * to a race condition in HSI HW protocol, clients need to be notified
713 * about wake line changes, so they can implement a workaround for it.
714 *
715 * Events:
716 * HSI_EVENT_START_RX - Incoming wake line high
717 * HSI_EVENT_STOP_RX - Incoming wake line down
718 *
719 * Returns -errno on error, or 0 on success.
720 */
hsi_event(struct hsi_port * port,unsigned long event)721 int hsi_event(struct hsi_port *port, unsigned long event)
722 {
723 return blocking_notifier_call_chain(&port->n_head, event, NULL);
724 }
725 EXPORT_SYMBOL_GPL(hsi_event);
726
727 /**
728 * hsi_get_channel_id_by_name - acquire channel id by channel name
729 * @cl: HSI client, which uses the channel
730 * @name: name the channel is known under
731 *
732 * Clients can call this function to get the hsi channel ids similar to
733 * requesting IRQs or GPIOs by name. This function assumes the same
734 * channel configuration is used for RX and TX.
735 *
736 * Returns -errno on error or channel id on success.
737 */
hsi_get_channel_id_by_name(struct hsi_client * cl,char * name)738 int hsi_get_channel_id_by_name(struct hsi_client *cl, char *name)
739 {
740 int i;
741
742 if (!cl->rx_cfg.channels)
743 return -ENOENT;
744
745 for (i = 0; i < cl->rx_cfg.num_channels; i++)
746 if (!strcmp(cl->rx_cfg.channels[i].name, name))
747 return cl->rx_cfg.channels[i].id;
748
749 return -ENXIO;
750 }
751 EXPORT_SYMBOL_GPL(hsi_get_channel_id_by_name);
752
hsi_init(void)753 static int __init hsi_init(void)
754 {
755 return bus_register(&hsi_bus_type);
756 }
757 postcore_initcall(hsi_init);
758
hsi_exit(void)759 static void __exit hsi_exit(void)
760 {
761 bus_unregister(&hsi_bus_type);
762 }
763 module_exit(hsi_exit);
764
765 MODULE_AUTHOR("Carlos Chinea <carlos.chinea@nokia.com>");
766 MODULE_DESCRIPTION("High-speed Synchronous Serial Interface (HSI) framework");
767 MODULE_LICENSE("GPL v2");
768