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