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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
22#include "bus.h"
23#include "dev.h"
24
25static DEFINE_MUTEX(clients_lock);
26static LIST_HEAD(clients);
27
28static DEFINE_MUTEX(drivers_lock);
29static LIST_HEAD(drivers);
30
31static DEFINE_MUTEX(devices_lock);
32static LIST_HEAD(devices);
33
34struct host1x_subdev {
35 struct host1x_client *client;
36 struct device_node *np;
37 struct list_head list;
38};
39
40/**
41 * host1x_subdev_add() - add a new subdevice with an associated device node
42 */
43static int host1x_subdev_add(struct host1x_device *device,
44 struct device_node *np)
45{
46 struct host1x_subdev *subdev;
47
48 subdev = kzalloc(sizeof(*subdev), GFP_KERNEL);
49 if (!subdev)
50 return -ENOMEM;
51
52 INIT_LIST_HEAD(&subdev->list);
53 subdev->np = of_node_get(np);
54
55 mutex_lock(&device->subdevs_lock);
56 list_add_tail(&subdev->list, &device->subdevs);
57 mutex_unlock(&device->subdevs_lock);
58
59 return 0;
60}
61
62/**
63 * host1x_subdev_del() - remove subdevice
64 */
65static void host1x_subdev_del(struct host1x_subdev *subdev)
66{
67 list_del(&subdev->list);
68 of_node_put(subdev->np);
69 kfree(subdev);
70}
71
72/**
73 * host1x_device_parse_dt() - scan device tree and add matching subdevices
74 */
75static int host1x_device_parse_dt(struct host1x_device *device)
76{
77 struct device_node *np;
78 int err;
79
80 for_each_child_of_node(device->dev.parent->of_node, np) {
81 if (of_match_node(device->driver->subdevs, np) &&
82 of_device_is_available(np)) {
83 err = host1x_subdev_add(device, np);
84 if (err < 0)
85 return err;
86 }
87 }
88
89 return 0;
90}
91
92static void host1x_subdev_register(struct host1x_device *device,
93 struct host1x_subdev *subdev,
94 struct host1x_client *client)
95{
96 int err;
97
98 /*
99 * Move the subdevice to the list of active (registered) subdevices
100 * and associate it with a client. At the same time, associate the
101 * client with its parent device.
102 */
103 mutex_lock(&device->subdevs_lock);
104 mutex_lock(&device->clients_lock);
105 list_move_tail(&client->list, &device->clients);
106 list_move_tail(&subdev->list, &device->active);
107 client->parent = &device->dev;
108 subdev->client = client;
109 mutex_unlock(&device->clients_lock);
110 mutex_unlock(&device->subdevs_lock);
111
112 /*
113 * When all subdevices have been registered, the composite device is
114 * ready to be probed.
115 */
116 if (list_empty(&device->subdevs)) {
117 err = device->driver->probe(device);
118 if (err < 0)
119 dev_err(&device->dev, "probe failed: %d\n", err);
120 }
121}
122
123static void __host1x_subdev_unregister(struct host1x_device *device,
124 struct host1x_subdev *subdev)
125{
126 struct host1x_client *client = subdev->client;
127 int err;
128
129 /*
130 * If all subdevices have been activated, we're about to remove the
131 * first active subdevice, so unload the driver first.
132 */
133 if (list_empty(&device->subdevs)) {
134 err = device->driver->remove(device);
135 if (err < 0)
136 dev_err(&device->dev, "remove failed: %d\n", err);
137 }
138
139 /*
140 * Move the subdevice back to the list of idle subdevices and remove
141 * it from list of clients.
142 */
143 mutex_lock(&device->clients_lock);
144 subdev->client = NULL;
145 client->parent = NULL;
146 list_move_tail(&subdev->list, &device->subdevs);
147 /*
148 * XXX: Perhaps don't do this here, but rather explicitly remove it
149 * when the device is about to be deleted.
150 *
151 * This is somewhat complicated by the fact that this function is
152 * used to remove the subdevice when a client is unregistered but
153 * also when the composite device is about to be removed.
154 */
155 list_del_init(&client->list);
156 mutex_unlock(&device->clients_lock);
157}
158
159static void host1x_subdev_unregister(struct host1x_device *device,
160 struct host1x_subdev *subdev)
161{
162 mutex_lock(&device->subdevs_lock);
163 __host1x_subdev_unregister(device, subdev);
164 mutex_unlock(&device->subdevs_lock);
165}
166
167int host1x_device_init(struct host1x_device *device)
168{
169 struct host1x_client *client;
170 int err;
171
172 mutex_lock(&device->clients_lock);
173
174 list_for_each_entry(client, &device->clients, list) {
175 if (client->ops && client->ops->init) {
176 err = client->ops->init(client);
177 if (err < 0) {
178 dev_err(&device->dev,
179 "failed to initialize %s: %d\n",
180 dev_name(client->dev), err);
181 mutex_unlock(&device->clients_lock);
182 return err;
183 }
184 }
185 }
186
187 mutex_unlock(&device->clients_lock);
188
189 return 0;
190}
191EXPORT_SYMBOL(host1x_device_init);
192
193int host1x_device_exit(struct host1x_device *device)
194{
195 struct host1x_client *client;
196 int err;
197
198 mutex_lock(&device->clients_lock);
199
200 list_for_each_entry_reverse(client, &device->clients, list) {
201 if (client->ops && client->ops->exit) {
202 err = client->ops->exit(client);
203 if (err < 0) {
204 dev_err(&device->dev,
205 "failed to cleanup %s: %d\n",
206 dev_name(client->dev), err);
207 mutex_unlock(&device->clients_lock);
208 return err;
209 }
210 }
211 }
212
213 mutex_unlock(&device->clients_lock);
214
215 return 0;
216}
217EXPORT_SYMBOL(host1x_device_exit);
218
219static int host1x_register_client(struct host1x *host1x,
220 struct host1x_client *client)
221{
222 struct host1x_device *device;
223 struct host1x_subdev *subdev;
224
225 mutex_lock(&host1x->devices_lock);
226
227 list_for_each_entry(device, &host1x->devices, list) {
228 list_for_each_entry(subdev, &device->subdevs, list) {
229 if (subdev->np == client->dev->of_node) {
230 host1x_subdev_register(device, subdev, client);
231 mutex_unlock(&host1x->devices_lock);
232 return 0;
233 }
234 }
235 }
236
237 mutex_unlock(&host1x->devices_lock);
238 return -ENODEV;
239}
240
241static int host1x_unregister_client(struct host1x *host1x,
242 struct host1x_client *client)
243{
244 struct host1x_device *device, *dt;
245 struct host1x_subdev *subdev;
246
247 mutex_lock(&host1x->devices_lock);
248
249 list_for_each_entry_safe(device, dt, &host1x->devices, list) {
250 list_for_each_entry(subdev, &device->active, list) {
251 if (subdev->client == client) {
252 host1x_subdev_unregister(device, subdev);
253 mutex_unlock(&host1x->devices_lock);
254 return 0;
255 }
256 }
257 }
258
259 mutex_unlock(&host1x->devices_lock);
260 return -ENODEV;
261}
262
263static struct bus_type host1x_bus_type = {
264 .name = "host1x",
265};
266
267int host1x_bus_init(void)
268{
269 return bus_register(&host1x_bus_type);
270}
271
272void host1x_bus_exit(void)
273{
274 bus_unregister(&host1x_bus_type);
275}
276
277static void host1x_device_release(struct device *dev)
278{
279 struct host1x_device *device = to_host1x_device(dev);
280
281 kfree(device);
282}
283
284static int host1x_device_add(struct host1x *host1x,
285 struct host1x_driver *driver)
286{
287 struct host1x_client *client, *tmp;
288 struct host1x_subdev *subdev;
289 struct host1x_device *device;
290 int err;
291
292 device = kzalloc(sizeof(*device), GFP_KERNEL);
293 if (!device)
294 return -ENOMEM;
295
296 mutex_init(&device->subdevs_lock);
297 INIT_LIST_HEAD(&device->subdevs);
298 INIT_LIST_HEAD(&device->active);
299 mutex_init(&device->clients_lock);
300 INIT_LIST_HEAD(&device->clients);
301 INIT_LIST_HEAD(&device->list);
302 device->driver = driver;
303
304 device->dev.coherent_dma_mask = host1x->dev->coherent_dma_mask;
305 device->dev.dma_mask = &device->dev.coherent_dma_mask;
306 device->dev.release = host1x_device_release;
307 dev_set_name(&device->dev, "%s", driver->name);
308 device->dev.bus = &host1x_bus_type;
309 device->dev.parent = host1x->dev;
310
311 err = device_register(&device->dev);
312 if (err < 0)
313 return err;
314
315 err = host1x_device_parse_dt(device);
316 if (err < 0) {
317 device_unregister(&device->dev);
318 return err;
319 }
320
321 mutex_lock(&host1x->devices_lock);
322 list_add_tail(&device->list, &host1x->devices);
323 mutex_unlock(&host1x->devices_lock);
324
325 mutex_lock(&clients_lock);
326
327 list_for_each_entry_safe(client, tmp, &clients, list) {
328 list_for_each_entry(subdev, &device->subdevs, list) {
329 if (subdev->np == client->dev->of_node) {
330 host1x_subdev_register(device, subdev, client);
331 break;
332 }
333 }
334 }
335
336 mutex_unlock(&clients_lock);
337
338 return 0;
339}
340
341/*
342 * Removes a device by first unregistering any subdevices and then removing
343 * itself from the list of devices.
344 *
345 * This function must be called with the host1x->devices_lock held.
346 */
347static void host1x_device_del(struct host1x *host1x,
348 struct host1x_device *device)
349{
350 struct host1x_subdev *subdev, *sd;
351 struct host1x_client *client, *cl;
352
353 mutex_lock(&device->subdevs_lock);
354
355 /* unregister subdevices */
356 list_for_each_entry_safe(subdev, sd, &device->active, list) {
357 /*
358 * host1x_subdev_unregister() will remove the client from
359 * any lists, so we'll need to manually add it back to the
360 * list of idle clients.
361 *
362 * XXX: Alternatively, perhaps don't remove the client from
363 * any lists in host1x_subdev_unregister() and instead do
364 * that explicitly from host1x_unregister_client()?
365 */
366 client = subdev->client;
367
368 __host1x_subdev_unregister(device, subdev);
369
370 /* add the client to the list of idle clients */
371 mutex_lock(&clients_lock);
372 list_add_tail(&client->list, &clients);
373 mutex_unlock(&clients_lock);
374 }
375
376 /* remove subdevices */
377 list_for_each_entry_safe(subdev, sd, &device->subdevs, list)
378 host1x_subdev_del(subdev);
379
380 mutex_unlock(&device->subdevs_lock);
381
382 /* move clients to idle list */
383 mutex_lock(&clients_lock);
384 mutex_lock(&device->clients_lock);
385
386 list_for_each_entry_safe(client, cl, &device->clients, list)
387 list_move_tail(&client->list, &clients);
388
389 mutex_unlock(&device->clients_lock);
390 mutex_unlock(&clients_lock);
391
392 /* finally remove the device */
393 list_del_init(&device->list);
394 device_unregister(&device->dev);
395}
396
397static void host1x_attach_driver(struct host1x *host1x,
398 struct host1x_driver *driver)
399{
400 struct host1x_device *device;
401 int err;
402
403 mutex_lock(&host1x->devices_lock);
404
405 list_for_each_entry(device, &host1x->devices, list) {
406 if (device->driver == driver) {
407 mutex_unlock(&host1x->devices_lock);
408 return;
409 }
410 }
411
412 mutex_unlock(&host1x->devices_lock);
413
414 err = host1x_device_add(host1x, driver);
415 if (err < 0)
416 dev_err(host1x->dev, "failed to allocate device: %d\n", err);
417}
418
419static void host1x_detach_driver(struct host1x *host1x,
420 struct host1x_driver *driver)
421{
422 struct host1x_device *device, *tmp;
423
424 mutex_lock(&host1x->devices_lock);
425
426 list_for_each_entry_safe(device, tmp, &host1x->devices, list)
427 if (device->driver == driver)
428 host1x_device_del(host1x, device);
429
430 mutex_unlock(&host1x->devices_lock);
431}
432
433int host1x_register(struct host1x *host1x)
434{
435 struct host1x_driver *driver;
436
437 mutex_lock(&devices_lock);
438 list_add_tail(&host1x->list, &devices);
439 mutex_unlock(&devices_lock);
440
441 mutex_lock(&drivers_lock);
442
443 list_for_each_entry(driver, &drivers, list)
444 host1x_attach_driver(host1x, driver);
445
446 mutex_unlock(&drivers_lock);
447
448 return 0;
449}
450
451int host1x_unregister(struct host1x *host1x)
452{
453 struct host1x_driver *driver;
454
455 mutex_lock(&drivers_lock);
456
457 list_for_each_entry(driver, &drivers, list)
458 host1x_detach_driver(host1x, driver);
459
460 mutex_unlock(&drivers_lock);
461
462 mutex_lock(&devices_lock);
463 list_del_init(&host1x->list);
464 mutex_unlock(&devices_lock);
465
466 return 0;
467}
468
469int host1x_driver_register(struct host1x_driver *driver)
470{
471 struct host1x *host1x;
472
473 INIT_LIST_HEAD(&driver->list);
474
475 mutex_lock(&drivers_lock);
476 list_add_tail(&driver->list, &drivers);
477 mutex_unlock(&drivers_lock);
478
479 mutex_lock(&devices_lock);
480
481 list_for_each_entry(host1x, &devices, list)
482 host1x_attach_driver(host1x, driver);
483
484 mutex_unlock(&devices_lock);
485
486 return 0;
487}
488EXPORT_SYMBOL(host1x_driver_register);
489
490void host1x_driver_unregister(struct host1x_driver *driver)
491{
492 mutex_lock(&drivers_lock);
493 list_del_init(&driver->list);
494 mutex_unlock(&drivers_lock);
495}
496EXPORT_SYMBOL(host1x_driver_unregister);
497
498int host1x_client_register(struct host1x_client *client)
499{
500 struct host1x *host1x;
501 int err;
502
503 mutex_lock(&devices_lock);
504
505 list_for_each_entry(host1x, &devices, list) {
506 err = host1x_register_client(host1x, client);
507 if (!err) {
508 mutex_unlock(&devices_lock);
509 return 0;
510 }
511 }
512
513 mutex_unlock(&devices_lock);
514
515 mutex_lock(&clients_lock);
516 list_add_tail(&client->list, &clients);
517 mutex_unlock(&clients_lock);
518
519 return 0;
520}
521EXPORT_SYMBOL(host1x_client_register);
522
523int host1x_client_unregister(struct host1x_client *client)
524{
525 struct host1x_client *c;
526 struct host1x *host1x;
527 int err;
528
529 mutex_lock(&devices_lock);
530
531 list_for_each_entry(host1x, &devices, list) {
532 err = host1x_unregister_client(host1x, client);
533 if (!err) {
534 mutex_unlock(&devices_lock);
535 return 0;
536 }
537 }
538
539 mutex_unlock(&devices_lock);
540 mutex_lock(&clients_lock);
541
542 list_for_each_entry(c, &clients, list) {
543 if (c == client) {
544 list_del_init(&c->list);
545 break;
546 }
547 }
548
549 mutex_unlock(&clients_lock);
550
551 return 0;
552}
553EXPORT_SYMBOL(host1x_client_unregister);