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1/*
2 * Copyright (C) 2012 Avionic Design GmbH
3 * Copyright (C) 2012-2013, NVIDIA Corporation
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms and conditions of the GNU General Public License,
7 * version 2, as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
12 * more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program. If not, see <http://www.gnu.org/licenses/>.
16 */
17
18#include <linux/host1x.h>
19#include <linux/of.h>
20#include <linux/slab.h>
21#include <linux/of_device.h>
22
23#include "bus.h"
24#include "dev.h"
25
26static DEFINE_MUTEX(clients_lock);
27static LIST_HEAD(clients);
28
29static DEFINE_MUTEX(drivers_lock);
30static LIST_HEAD(drivers);
31
32static DEFINE_MUTEX(devices_lock);
33static LIST_HEAD(devices);
34
35struct host1x_subdev {
36 struct host1x_client *client;
37 struct device_node *np;
38 struct list_head list;
39};
40
41/**
42 * host1x_subdev_add() - add a new subdevice with an associated device node
43 * @device: host1x device to add the subdevice to
44 * @np: device node
45 */
46static int host1x_subdev_add(struct host1x_device *device,
47 struct host1x_driver *driver,
48 struct device_node *np)
49{
50 struct host1x_subdev *subdev;
51 struct device_node *child;
52 int err;
53
54 subdev = kzalloc(sizeof(*subdev), GFP_KERNEL);
55 if (!subdev)
56 return -ENOMEM;
57
58 INIT_LIST_HEAD(&subdev->list);
59 subdev->np = of_node_get(np);
60
61 mutex_lock(&device->subdevs_lock);
62 list_add_tail(&subdev->list, &device->subdevs);
63 mutex_unlock(&device->subdevs_lock);
64
65 /* recursively add children */
66 for_each_child_of_node(np, child) {
67 if (of_match_node(driver->subdevs, child) &&
68 of_device_is_available(child)) {
69 err = host1x_subdev_add(device, driver, child);
70 if (err < 0) {
71 /* XXX cleanup? */
72 of_node_put(child);
73 return err;
74 }
75 }
76 }
77
78 return 0;
79}
80
81/**
82 * host1x_subdev_del() - remove subdevice
83 * @subdev: subdevice to remove
84 */
85static void host1x_subdev_del(struct host1x_subdev *subdev)
86{
87 list_del(&subdev->list);
88 of_node_put(subdev->np);
89 kfree(subdev);
90}
91
92/**
93 * host1x_device_parse_dt() - scan device tree and add matching subdevices
94 * @device: host1x logical device
95 * @driver: host1x driver
96 */
97static int host1x_device_parse_dt(struct host1x_device *device,
98 struct host1x_driver *driver)
99{
100 struct device_node *np;
101 int err;
102
103 for_each_child_of_node(device->dev.parent->of_node, np) {
104 if (of_match_node(driver->subdevs, np) &&
105 of_device_is_available(np)) {
106 err = host1x_subdev_add(device, driver, np);
107 if (err < 0) {
108 of_node_put(np);
109 return err;
110 }
111 }
112 }
113
114 return 0;
115}
116
117static void host1x_subdev_register(struct host1x_device *device,
118 struct host1x_subdev *subdev,
119 struct host1x_client *client)
120{
121 int err;
122
123 /*
124 * Move the subdevice to the list of active (registered) subdevices
125 * and associate it with a client. At the same time, associate the
126 * client with its parent device.
127 */
128 mutex_lock(&device->subdevs_lock);
129 mutex_lock(&device->clients_lock);
130 list_move_tail(&client->list, &device->clients);
131 list_move_tail(&subdev->list, &device->active);
132 client->parent = &device->dev;
133 subdev->client = client;
134 mutex_unlock(&device->clients_lock);
135 mutex_unlock(&device->subdevs_lock);
136
137 if (list_empty(&device->subdevs)) {
138 err = device_add(&device->dev);
139 if (err < 0)
140 dev_err(&device->dev, "failed to add: %d\n", err);
141 else
142 device->registered = true;
143 }
144}
145
146static void __host1x_subdev_unregister(struct host1x_device *device,
147 struct host1x_subdev *subdev)
148{
149 struct host1x_client *client = subdev->client;
150
151 /*
152 * If all subdevices have been activated, we're about to remove the
153 * first active subdevice, so unload the driver first.
154 */
155 if (list_empty(&device->subdevs)) {
156 if (device->registered) {
157 device->registered = false;
158 device_del(&device->dev);
159 }
160 }
161
162 /*
163 * Move the subdevice back to the list of idle subdevices and remove
164 * it from list of clients.
165 */
166 mutex_lock(&device->clients_lock);
167 subdev->client = NULL;
168 client->parent = NULL;
169 list_move_tail(&subdev->list, &device->subdevs);
170 /*
171 * XXX: Perhaps don't do this here, but rather explicitly remove it
172 * when the device is about to be deleted.
173 *
174 * This is somewhat complicated by the fact that this function is
175 * used to remove the subdevice when a client is unregistered but
176 * also when the composite device is about to be removed.
177 */
178 list_del_init(&client->list);
179 mutex_unlock(&device->clients_lock);
180}
181
182static void host1x_subdev_unregister(struct host1x_device *device,
183 struct host1x_subdev *subdev)
184{
185 mutex_lock(&device->subdevs_lock);
186 __host1x_subdev_unregister(device, subdev);
187 mutex_unlock(&device->subdevs_lock);
188}
189
190/**
191 * host1x_device_init() - initialize a host1x logical device
192 * @device: host1x logical device
193 *
194 * The driver for the host1x logical device can call this during execution of
195 * its &host1x_driver.probe implementation to initialize each of its clients.
196 * The client drivers access the subsystem specific driver data using the
197 * &host1x_client.parent field and driver data associated with it (usually by
198 * calling dev_get_drvdata()).
199 */
200int host1x_device_init(struct host1x_device *device)
201{
202 struct host1x_client *client;
203 int err;
204
205 mutex_lock(&device->clients_lock);
206
207 list_for_each_entry(client, &device->clients, list) {
208 if (client->ops && client->ops->init) {
209 err = client->ops->init(client);
210 if (err < 0) {
211 dev_err(&device->dev,
212 "failed to initialize %s: %d\n",
213 dev_name(client->dev), err);
214 goto teardown;
215 }
216 }
217 }
218
219 mutex_unlock(&device->clients_lock);
220
221 return 0;
222
223teardown:
224 list_for_each_entry_continue_reverse(client, &device->clients, list)
225 if (client->ops->exit)
226 client->ops->exit(client);
227
228 mutex_unlock(&device->clients_lock);
229 return err;
230}
231EXPORT_SYMBOL(host1x_device_init);
232
233/**
234 * host1x_device_exit() - uninitialize host1x logical device
235 * @device: host1x logical device
236 *
237 * When the driver for a host1x logical device is unloaded, it can call this
238 * function to tear down each of its clients. Typically this is done after a
239 * subsystem-specific data structure is removed and the functionality can no
240 * longer be used.
241 */
242int host1x_device_exit(struct host1x_device *device)
243{
244 struct host1x_client *client;
245 int err;
246
247 mutex_lock(&device->clients_lock);
248
249 list_for_each_entry_reverse(client, &device->clients, list) {
250 if (client->ops && client->ops->exit) {
251 err = client->ops->exit(client);
252 if (err < 0) {
253 dev_err(&device->dev,
254 "failed to cleanup %s: %d\n",
255 dev_name(client->dev), err);
256 mutex_unlock(&device->clients_lock);
257 return err;
258 }
259 }
260 }
261
262 mutex_unlock(&device->clients_lock);
263
264 return 0;
265}
266EXPORT_SYMBOL(host1x_device_exit);
267
268static int host1x_add_client(struct host1x *host1x,
269 struct host1x_client *client)
270{
271 struct host1x_device *device;
272 struct host1x_subdev *subdev;
273
274 mutex_lock(&host1x->devices_lock);
275
276 list_for_each_entry(device, &host1x->devices, list) {
277 list_for_each_entry(subdev, &device->subdevs, list) {
278 if (subdev->np == client->dev->of_node) {
279 host1x_subdev_register(device, subdev, client);
280 mutex_unlock(&host1x->devices_lock);
281 return 0;
282 }
283 }
284 }
285
286 mutex_unlock(&host1x->devices_lock);
287 return -ENODEV;
288}
289
290static int host1x_del_client(struct host1x *host1x,
291 struct host1x_client *client)
292{
293 struct host1x_device *device, *dt;
294 struct host1x_subdev *subdev;
295
296 mutex_lock(&host1x->devices_lock);
297
298 list_for_each_entry_safe(device, dt, &host1x->devices, list) {
299 list_for_each_entry(subdev, &device->active, list) {
300 if (subdev->client == client) {
301 host1x_subdev_unregister(device, subdev);
302 mutex_unlock(&host1x->devices_lock);
303 return 0;
304 }
305 }
306 }
307
308 mutex_unlock(&host1x->devices_lock);
309 return -ENODEV;
310}
311
312static int host1x_device_match(struct device *dev, struct device_driver *drv)
313{
314 return strcmp(dev_name(dev), drv->name) == 0;
315}
316
317static const struct dev_pm_ops host1x_device_pm_ops = {
318 .suspend = pm_generic_suspend,
319 .resume = pm_generic_resume,
320 .freeze = pm_generic_freeze,
321 .thaw = pm_generic_thaw,
322 .poweroff = pm_generic_poweroff,
323 .restore = pm_generic_restore,
324};
325
326struct bus_type host1x_bus_type = {
327 .name = "host1x",
328 .match = host1x_device_match,
329 .pm = &host1x_device_pm_ops,
330 .force_dma = true,
331};
332
333static void __host1x_device_del(struct host1x_device *device)
334{
335 struct host1x_subdev *subdev, *sd;
336 struct host1x_client *client, *cl;
337
338 mutex_lock(&device->subdevs_lock);
339
340 /* unregister subdevices */
341 list_for_each_entry_safe(subdev, sd, &device->active, list) {
342 /*
343 * host1x_subdev_unregister() will remove the client from
344 * any lists, so we'll need to manually add it back to the
345 * list of idle clients.
346 *
347 * XXX: Alternatively, perhaps don't remove the client from
348 * any lists in host1x_subdev_unregister() and instead do
349 * that explicitly from host1x_unregister_client()?
350 */
351 client = subdev->client;
352
353 __host1x_subdev_unregister(device, subdev);
354
355 /* add the client to the list of idle clients */
356 mutex_lock(&clients_lock);
357 list_add_tail(&client->list, &clients);
358 mutex_unlock(&clients_lock);
359 }
360
361 /* remove subdevices */
362 list_for_each_entry_safe(subdev, sd, &device->subdevs, list)
363 host1x_subdev_del(subdev);
364
365 mutex_unlock(&device->subdevs_lock);
366
367 /* move clients to idle list */
368 mutex_lock(&clients_lock);
369 mutex_lock(&device->clients_lock);
370
371 list_for_each_entry_safe(client, cl, &device->clients, list)
372 list_move_tail(&client->list, &clients);
373
374 mutex_unlock(&device->clients_lock);
375 mutex_unlock(&clients_lock);
376
377 /* finally remove the device */
378 list_del_init(&device->list);
379}
380
381static void host1x_device_release(struct device *dev)
382{
383 struct host1x_device *device = to_host1x_device(dev);
384
385 __host1x_device_del(device);
386 kfree(device);
387}
388
389static int host1x_device_add(struct host1x *host1x,
390 struct host1x_driver *driver)
391{
392 struct host1x_client *client, *tmp;
393 struct host1x_subdev *subdev;
394 struct host1x_device *device;
395 int err;
396
397 device = kzalloc(sizeof(*device), GFP_KERNEL);
398 if (!device)
399 return -ENOMEM;
400
401 device_initialize(&device->dev);
402
403 mutex_init(&device->subdevs_lock);
404 INIT_LIST_HEAD(&device->subdevs);
405 INIT_LIST_HEAD(&device->active);
406 mutex_init(&device->clients_lock);
407 INIT_LIST_HEAD(&device->clients);
408 INIT_LIST_HEAD(&device->list);
409 device->driver = driver;
410
411 device->dev.coherent_dma_mask = host1x->dev->coherent_dma_mask;
412 device->dev.dma_mask = &device->dev.coherent_dma_mask;
413 dev_set_name(&device->dev, "%s", driver->driver.name);
414 device->dev.release = host1x_device_release;
415 device->dev.of_node = host1x->dev->of_node;
416 device->dev.bus = &host1x_bus_type;
417 device->dev.parent = host1x->dev;
418
419 of_dma_configure(&device->dev, host1x->dev->of_node);
420
421 err = host1x_device_parse_dt(device, driver);
422 if (err < 0) {
423 kfree(device);
424 return err;
425 }
426
427 list_add_tail(&device->list, &host1x->devices);
428
429 mutex_lock(&clients_lock);
430
431 list_for_each_entry_safe(client, tmp, &clients, list) {
432 list_for_each_entry(subdev, &device->subdevs, list) {
433 if (subdev->np == client->dev->of_node) {
434 host1x_subdev_register(device, subdev, client);
435 break;
436 }
437 }
438 }
439
440 mutex_unlock(&clients_lock);
441
442 return 0;
443}
444
445/*
446 * Removes a device by first unregistering any subdevices and then removing
447 * itself from the list of devices.
448 *
449 * This function must be called with the host1x->devices_lock held.
450 */
451static void host1x_device_del(struct host1x *host1x,
452 struct host1x_device *device)
453{
454 if (device->registered) {
455 device->registered = false;
456 device_del(&device->dev);
457 }
458
459 put_device(&device->dev);
460}
461
462static void host1x_attach_driver(struct host1x *host1x,
463 struct host1x_driver *driver)
464{
465 struct host1x_device *device;
466 int err;
467
468 mutex_lock(&host1x->devices_lock);
469
470 list_for_each_entry(device, &host1x->devices, list) {
471 if (device->driver == driver) {
472 mutex_unlock(&host1x->devices_lock);
473 return;
474 }
475 }
476
477 err = host1x_device_add(host1x, driver);
478 if (err < 0)
479 dev_err(host1x->dev, "failed to allocate device: %d\n", err);
480
481 mutex_unlock(&host1x->devices_lock);
482}
483
484static void host1x_detach_driver(struct host1x *host1x,
485 struct host1x_driver *driver)
486{
487 struct host1x_device *device, *tmp;
488
489 mutex_lock(&host1x->devices_lock);
490
491 list_for_each_entry_safe(device, tmp, &host1x->devices, list)
492 if (device->driver == driver)
493 host1x_device_del(host1x, device);
494
495 mutex_unlock(&host1x->devices_lock);
496}
497
498/**
499 * host1x_register() - register a host1x controller
500 * @host1x: host1x controller
501 *
502 * The host1x controller driver uses this to register a host1x controller with
503 * the infrastructure. Note that all Tegra SoC generations have only ever come
504 * with a single host1x instance, so this function is somewhat academic.
505 */
506int host1x_register(struct host1x *host1x)
507{
508 struct host1x_driver *driver;
509
510 mutex_lock(&devices_lock);
511 list_add_tail(&host1x->list, &devices);
512 mutex_unlock(&devices_lock);
513
514 mutex_lock(&drivers_lock);
515
516 list_for_each_entry(driver, &drivers, list)
517 host1x_attach_driver(host1x, driver);
518
519 mutex_unlock(&drivers_lock);
520
521 return 0;
522}
523
524/**
525 * host1x_unregister() - unregister a host1x controller
526 * @host1x: host1x controller
527 *
528 * The host1x controller driver uses this to remove a host1x controller from
529 * the infrastructure.
530 */
531int host1x_unregister(struct host1x *host1x)
532{
533 struct host1x_driver *driver;
534
535 mutex_lock(&drivers_lock);
536
537 list_for_each_entry(driver, &drivers, list)
538 host1x_detach_driver(host1x, driver);
539
540 mutex_unlock(&drivers_lock);
541
542 mutex_lock(&devices_lock);
543 list_del_init(&host1x->list);
544 mutex_unlock(&devices_lock);
545
546 return 0;
547}
548
549static int host1x_device_probe(struct device *dev)
550{
551 struct host1x_driver *driver = to_host1x_driver(dev->driver);
552 struct host1x_device *device = to_host1x_device(dev);
553
554 if (driver->probe)
555 return driver->probe(device);
556
557 return 0;
558}
559
560static int host1x_device_remove(struct device *dev)
561{
562 struct host1x_driver *driver = to_host1x_driver(dev->driver);
563 struct host1x_device *device = to_host1x_device(dev);
564
565 if (driver->remove)
566 return driver->remove(device);
567
568 return 0;
569}
570
571static void host1x_device_shutdown(struct device *dev)
572{
573 struct host1x_driver *driver = to_host1x_driver(dev->driver);
574 struct host1x_device *device = to_host1x_device(dev);
575
576 if (driver->shutdown)
577 driver->shutdown(device);
578}
579
580/**
581 * host1x_driver_register_full() - register a host1x driver
582 * @driver: host1x driver
583 * @owner: owner module
584 *
585 * Drivers for host1x logical devices call this function to register a driver
586 * with the infrastructure. Note that since these drive logical devices, the
587 * registration of the driver actually triggers tho logical device creation.
588 * A logical device will be created for each host1x instance.
589 */
590int host1x_driver_register_full(struct host1x_driver *driver,
591 struct module *owner)
592{
593 struct host1x *host1x;
594
595 INIT_LIST_HEAD(&driver->list);
596
597 mutex_lock(&drivers_lock);
598 list_add_tail(&driver->list, &drivers);
599 mutex_unlock(&drivers_lock);
600
601 mutex_lock(&devices_lock);
602
603 list_for_each_entry(host1x, &devices, list)
604 host1x_attach_driver(host1x, driver);
605
606 mutex_unlock(&devices_lock);
607
608 driver->driver.bus = &host1x_bus_type;
609 driver->driver.owner = owner;
610 driver->driver.probe = host1x_device_probe;
611 driver->driver.remove = host1x_device_remove;
612 driver->driver.shutdown = host1x_device_shutdown;
613
614 return driver_register(&driver->driver);
615}
616EXPORT_SYMBOL(host1x_driver_register_full);
617
618/**
619 * host1x_driver_unregister() - unregister a host1x driver
620 * @driver: host1x driver
621 *
622 * Unbinds the driver from each of the host1x logical devices that it is
623 * bound to, effectively removing the subsystem devices that they represent.
624 */
625void host1x_driver_unregister(struct host1x_driver *driver)
626{
627 driver_unregister(&driver->driver);
628
629 mutex_lock(&drivers_lock);
630 list_del_init(&driver->list);
631 mutex_unlock(&drivers_lock);
632}
633EXPORT_SYMBOL(host1x_driver_unregister);
634
635/**
636 * host1x_client_register() - register a host1x client
637 * @client: host1x client
638 *
639 * Registers a host1x client with each host1x controller instance. Note that
640 * each client will only match their parent host1x controller and will only be
641 * associated with that instance. Once all clients have been registered with
642 * their parent host1x controller, the infrastructure will set up the logical
643 * device and call host1x_device_init(), which will in turn call each client's
644 * &host1x_client_ops.init implementation.
645 */
646int host1x_client_register(struct host1x_client *client)
647{
648 struct host1x *host1x;
649 int err;
650
651 mutex_lock(&devices_lock);
652
653 list_for_each_entry(host1x, &devices, list) {
654 err = host1x_add_client(host1x, client);
655 if (!err) {
656 mutex_unlock(&devices_lock);
657 return 0;
658 }
659 }
660
661 mutex_unlock(&devices_lock);
662
663 mutex_lock(&clients_lock);
664 list_add_tail(&client->list, &clients);
665 mutex_unlock(&clients_lock);
666
667 return 0;
668}
669EXPORT_SYMBOL(host1x_client_register);
670
671/**
672 * host1x_client_unregister() - unregister a host1x client
673 * @client: host1x client
674 *
675 * Removes a host1x client from its host1x controller instance. If a logical
676 * device has already been initialized, it will be torn down.
677 */
678int host1x_client_unregister(struct host1x_client *client)
679{
680 struct host1x_client *c;
681 struct host1x *host1x;
682 int err;
683
684 mutex_lock(&devices_lock);
685
686 list_for_each_entry(host1x, &devices, list) {
687 err = host1x_del_client(host1x, client);
688 if (!err) {
689 mutex_unlock(&devices_lock);
690 return 0;
691 }
692 }
693
694 mutex_unlock(&devices_lock);
695 mutex_lock(&clients_lock);
696
697 list_for_each_entry(c, &clients, list) {
698 if (c == client) {
699 list_del_init(&c->list);
700 break;
701 }
702 }
703
704 mutex_unlock(&clients_lock);
705
706 return 0;
707}
708EXPORT_SYMBOL(host1x_client_unregister);