blob: df380d55c58fc916c35c8a680aab2e28f86a1584 [file] [log] [blame]
Carlos Chineaa056ab82010-04-16 19:01:02 +03001/*
2 * HSI core.
3 *
4 * Copyright (C) 2010 Nokia Corporation. All rights reserved.
5 *
6 * Contact: Carlos Chinea <carlos.chinea@nokia.com>
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * version 2 as published by the Free Software Foundation.
11 *
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
20 * 02110-1301 USA
21 */
22#include <linux/hsi/hsi.h>
23#include <linux/compiler.h>
Carlos Chineaa056ab82010-04-16 19:01:02 +030024#include <linux/list.h>
Carlos Chineaa056ab82010-04-16 19:01:02 +030025#include <linux/kobject.h>
26#include <linux/slab.h>
27#include <linux/string.h>
Carlos Chineaec1c56f2012-04-11 10:55:53 +030028#include <linux/notifier.h>
Sebastian Reichela2aa2472014-03-28 22:59:43 +010029#include <linux/of.h>
30#include <linux/of_device.h>
Carlos Chineaa056ab82010-04-16 19:01:02 +030031#include "hsi_core.h"
32
Carlos Chineaa056ab82010-04-16 19:01:02 +030033static ssize_t modalias_show(struct device *dev,
34 struct device_attribute *a __maybe_unused, char *buf)
35{
36 return sprintf(buf, "hsi:%s\n", dev_name(dev));
37}
Greg Kroah-Hartman00173142013-10-06 23:55:50 -070038static DEVICE_ATTR_RO(modalias);
Carlos Chineaa056ab82010-04-16 19:01:02 +030039
Greg Kroah-Hartman00173142013-10-06 23:55:50 -070040static struct attribute *hsi_bus_dev_attrs[] = {
41 &dev_attr_modalias.attr,
42 NULL,
Carlos Chineaa056ab82010-04-16 19:01:02 +030043};
Greg Kroah-Hartman00173142013-10-06 23:55:50 -070044ATTRIBUTE_GROUPS(hsi_bus_dev);
Carlos Chineaa056ab82010-04-16 19:01:02 +030045
46static int hsi_bus_uevent(struct device *dev, struct kobj_uevent_env *env)
47{
Carlos Chinea6f02b9e2012-04-10 15:11:24 +030048 add_uevent_var(env, "MODALIAS=hsi:%s", dev_name(dev));
Carlos Chineaa056ab82010-04-16 19:01:02 +030049
50 return 0;
51}
52
53static int hsi_bus_match(struct device *dev, struct device_driver *driver)
54{
Sebastian Reichela2aa2472014-03-28 22:59:43 +010055 if (of_driver_match_device(dev, driver))
56 return true;
57
58 if (strcmp(dev_name(dev), driver->name) == 0)
59 return true;
60
61 return false;
Carlos Chineaa056ab82010-04-16 19:01:02 +030062}
63
64static struct bus_type hsi_bus_type = {
65 .name = "hsi",
Greg Kroah-Hartman00173142013-10-06 23:55:50 -070066 .dev_groups = hsi_bus_dev_groups,
Carlos Chineaa056ab82010-04-16 19:01:02 +030067 .match = hsi_bus_match,
68 .uevent = hsi_bus_uevent,
69};
70
71static void hsi_client_release(struct device *dev)
72{
Sebastian Reichela088cf12014-03-28 22:48:23 +010073 struct hsi_client *cl = to_hsi_client(dev);
74
75 kfree(cl->tx_cfg.channels);
76 kfree(cl->rx_cfg.channels);
77 kfree(cl);
Carlos Chineaa056ab82010-04-16 19:01:02 +030078}
79
Sebastian Reichel84914512014-03-28 22:54:25 +010080struct hsi_client *hsi_new_client(struct hsi_port *port,
81 struct hsi_board_info *info)
Carlos Chineaa056ab82010-04-16 19:01:02 +030082{
83 struct hsi_client *cl;
Sebastian Reichela088cf12014-03-28 22:48:23 +010084 size_t size;
Carlos Chineaa056ab82010-04-16 19:01:02 +030085
86 cl = kzalloc(sizeof(*cl), GFP_KERNEL);
87 if (!cl)
Insu Yund2c85ac2015-10-17 19:25:07 +000088 goto err;
Sebastian Reichela088cf12014-03-28 22:48:23 +010089
Carlos Chineaa056ab82010-04-16 19:01:02 +030090 cl->tx_cfg = info->tx_cfg;
Sebastian Reichela088cf12014-03-28 22:48:23 +010091 if (cl->tx_cfg.channels) {
92 size = cl->tx_cfg.num_channels * sizeof(*cl->tx_cfg.channels);
93 cl->tx_cfg.channels = kzalloc(size , GFP_KERNEL);
Insu Yund2c85ac2015-10-17 19:25:07 +000094 if (!cl->tx_cfg.channels)
95 goto err_tx;
Sebastian Reichela088cf12014-03-28 22:48:23 +010096 memcpy(cl->tx_cfg.channels, info->tx_cfg.channels, size);
97 }
98
Carlos Chineaa056ab82010-04-16 19:01:02 +030099 cl->rx_cfg = info->rx_cfg;
Sebastian Reichela088cf12014-03-28 22:48:23 +0100100 if (cl->rx_cfg.channels) {
101 size = cl->rx_cfg.num_channels * sizeof(*cl->rx_cfg.channels);
102 cl->rx_cfg.channels = kzalloc(size , GFP_KERNEL);
Insu Yund2c85ac2015-10-17 19:25:07 +0000103 if (!cl->rx_cfg.channels)
104 goto err_rx;
Sebastian Reichela088cf12014-03-28 22:48:23 +0100105 memcpy(cl->rx_cfg.channels, info->rx_cfg.channels, size);
106 }
107
Carlos Chineaa056ab82010-04-16 19:01:02 +0300108 cl->device.bus = &hsi_bus_type;
109 cl->device.parent = &port->device;
110 cl->device.release = hsi_client_release;
Kees Cook02aa2a32013-07-03 15:04:56 -0700111 dev_set_name(&cl->device, "%s", info->name);
Carlos Chineaa056ab82010-04-16 19:01:02 +0300112 cl->device.platform_data = info->platform_data;
Carlos Chineaa056ab82010-04-16 19:01:02 +0300113 if (info->archdata)
114 cl->device.archdata = *info->archdata;
115 if (device_register(&cl->device) < 0) {
116 pr_err("hsi: failed to register client: %s\n", info->name);
Carlos Chinea90e41f92012-04-11 11:01:11 +0300117 put_device(&cl->device);
Carlos Chineaa056ab82010-04-16 19:01:02 +0300118 }
Sebastian Reichel84914512014-03-28 22:54:25 +0100119
120 return cl;
Insu Yund2c85ac2015-10-17 19:25:07 +0000121err_rx:
122 kfree(cl->tx_cfg.channels);
123err_tx:
124 kfree(cl);
125err:
126 return NULL;
Carlos Chineaa056ab82010-04-16 19:01:02 +0300127}
Sebastian Reichel84914512014-03-28 22:54:25 +0100128EXPORT_SYMBOL_GPL(hsi_new_client);
Carlos Chineaa056ab82010-04-16 19:01:02 +0300129
130static void hsi_scan_board_info(struct hsi_controller *hsi)
131{
132 struct hsi_cl_info *cl_info;
133 struct hsi_port *p;
134
135 list_for_each_entry(cl_info, &hsi_board_list, list)
136 if (cl_info->info.hsi_id == hsi->id) {
137 p = hsi_find_port_num(hsi, cl_info->info.port);
138 if (!p)
139 continue;
140 hsi_new_client(p, &cl_info->info);
141 }
142}
143
Sebastian Reichela2aa2472014-03-28 22:59:43 +0100144#ifdef CONFIG_OF
145static struct hsi_board_info hsi_char_dev_info = {
146 .name = "hsi_char",
147};
148
149static int hsi_of_property_parse_mode(struct device_node *client, char *name,
150 unsigned int *result)
151{
152 const char *mode;
153 int err;
154
155 err = of_property_read_string(client, name, &mode);
156 if (err < 0)
157 return err;
158
159 if (strcmp(mode, "stream") == 0)
160 *result = HSI_MODE_STREAM;
161 else if (strcmp(mode, "frame") == 0)
162 *result = HSI_MODE_FRAME;
163 else
164 return -EINVAL;
165
166 return 0;
167}
168
169static int hsi_of_property_parse_flow(struct device_node *client, char *name,
170 unsigned int *result)
171{
172 const char *flow;
173 int err;
174
175 err = of_property_read_string(client, name, &flow);
176 if (err < 0)
177 return err;
178
179 if (strcmp(flow, "synchronized") == 0)
180 *result = HSI_FLOW_SYNC;
181 else if (strcmp(flow, "pipeline") == 0)
182 *result = HSI_FLOW_PIPE;
183 else
184 return -EINVAL;
185
186 return 0;
187}
188
189static int hsi_of_property_parse_arb_mode(struct device_node *client,
190 char *name, unsigned int *result)
191{
192 const char *arb_mode;
193 int err;
194
195 err = of_property_read_string(client, name, &arb_mode);
196 if (err < 0)
197 return err;
198
199 if (strcmp(arb_mode, "round-robin") == 0)
200 *result = HSI_ARB_RR;
201 else if (strcmp(arb_mode, "priority") == 0)
202 *result = HSI_ARB_PRIO;
203 else
204 return -EINVAL;
205
206 return 0;
207}
208
209static void hsi_add_client_from_dt(struct hsi_port *port,
210 struct device_node *client)
211{
212 struct hsi_client *cl;
213 struct hsi_channel channel;
214 struct property *prop;
215 char name[32];
216 int length, cells, err, i, max_chan, mode;
217
218 cl = kzalloc(sizeof(*cl), GFP_KERNEL);
219 if (!cl)
220 return;
221
222 err = of_modalias_node(client, name, sizeof(name));
223 if (err)
224 goto err;
225
226 dev_set_name(&cl->device, "%s", name);
227
228 err = hsi_of_property_parse_mode(client, "hsi-mode", &mode);
229 if (err) {
230 err = hsi_of_property_parse_mode(client, "hsi-rx-mode",
231 &cl->rx_cfg.mode);
232 if (err)
233 goto err;
234
235 err = hsi_of_property_parse_mode(client, "hsi-tx-mode",
236 &cl->tx_cfg.mode);
237 if (err)
238 goto err;
239 } else {
240 cl->rx_cfg.mode = mode;
241 cl->tx_cfg.mode = mode;
242 }
243
244 err = of_property_read_u32(client, "hsi-speed-kbps",
245 &cl->tx_cfg.speed);
246 if (err)
247 goto err;
248 cl->rx_cfg.speed = cl->tx_cfg.speed;
249
250 err = hsi_of_property_parse_flow(client, "hsi-flow",
251 &cl->rx_cfg.flow);
252 if (err)
253 goto err;
254
255 err = hsi_of_property_parse_arb_mode(client, "hsi-arb-mode",
256 &cl->rx_cfg.arb_mode);
257 if (err)
258 goto err;
259
260 prop = of_find_property(client, "hsi-channel-ids", &length);
261 if (!prop) {
262 err = -EINVAL;
263 goto err;
264 }
265
266 cells = length / sizeof(u32);
267
268 cl->rx_cfg.num_channels = cells;
269 cl->tx_cfg.num_channels = cells;
270
271 cl->rx_cfg.channels = kzalloc(cells * sizeof(channel), GFP_KERNEL);
272 if (!cl->rx_cfg.channels) {
273 err = -ENOMEM;
274 goto err;
275 }
276
277 cl->tx_cfg.channels = kzalloc(cells * sizeof(channel), GFP_KERNEL);
278 if (!cl->tx_cfg.channels) {
279 err = -ENOMEM;
280 goto err2;
281 }
282
283 max_chan = 0;
284 for (i = 0; i < cells; i++) {
285 err = of_property_read_u32_index(client, "hsi-channel-ids", i,
286 &channel.id);
287 if (err)
288 goto err3;
289
290 err = of_property_read_string_index(client, "hsi-channel-names",
291 i, &channel.name);
292 if (err)
293 channel.name = NULL;
294
295 if (channel.id > max_chan)
296 max_chan = channel.id;
297
298 cl->rx_cfg.channels[i] = channel;
299 cl->tx_cfg.channels[i] = channel;
300 }
301
302 cl->rx_cfg.num_hw_channels = max_chan + 1;
303 cl->tx_cfg.num_hw_channels = max_chan + 1;
304
305 cl->device.bus = &hsi_bus_type;
306 cl->device.parent = &port->device;
307 cl->device.release = hsi_client_release;
308 cl->device.of_node = client;
309
310 if (device_register(&cl->device) < 0) {
311 pr_err("hsi: failed to register client: %s\n", name);
312 put_device(&cl->device);
Sebastian Reichela2aa2472014-03-28 22:59:43 +0100313 }
314
315 return;
316
317err3:
318 kfree(cl->tx_cfg.channels);
319err2:
320 kfree(cl->rx_cfg.channels);
321err:
322 kfree(cl);
323 pr_err("hsi client: missing or incorrect of property: err=%d\n", err);
324}
325
326void hsi_add_clients_from_dt(struct hsi_port *port, struct device_node *clients)
327{
328 struct device_node *child;
329
330 /* register hsi-char device */
331 hsi_new_client(port, &hsi_char_dev_info);
332
333 for_each_available_child_of_node(clients, child)
334 hsi_add_client_from_dt(port, child);
335}
336EXPORT_SYMBOL_GPL(hsi_add_clients_from_dt);
337#endif
338
Sebastian Reichel84914512014-03-28 22:54:25 +0100339int hsi_remove_client(struct device *dev, void *data __maybe_unused)
Carlos Chineaa056ab82010-04-16 19:01:02 +0300340{
Carlos Chineaa056ab82010-04-16 19:01:02 +0300341 device_unregister(dev);
342
343 return 0;
344}
Sebastian Reichel84914512014-03-28 22:54:25 +0100345EXPORT_SYMBOL_GPL(hsi_remove_client);
Carlos Chineaa056ab82010-04-16 19:01:02 +0300346
347static int hsi_remove_port(struct device *dev, void *data __maybe_unused)
348{
349 device_for_each_child(dev, NULL, hsi_remove_client);
350 device_unregister(dev);
351
352 return 0;
353}
354
Carlos Chinea5a218ce2012-04-04 14:11:45 +0300355static void hsi_controller_release(struct device *dev)
Carlos Chineaa056ab82010-04-16 19:01:02 +0300356{
Carlos Chinea5a218ce2012-04-04 14:11:45 +0300357 struct hsi_controller *hsi = to_hsi_controller(dev);
358
359 kfree(hsi->port);
360 kfree(hsi);
Carlos Chineaa056ab82010-04-16 19:01:02 +0300361}
362
Carlos Chinea5a218ce2012-04-04 14:11:45 +0300363static void hsi_port_release(struct device *dev)
Carlos Chineaa056ab82010-04-16 19:01:02 +0300364{
Carlos Chinea5a218ce2012-04-04 14:11:45 +0300365 kfree(to_hsi_port(dev));
Carlos Chineaa056ab82010-04-16 19:01:02 +0300366}
367
368/**
Sebastian Reichela0bf37e2013-10-06 20:23:49 +0200369 * hsi_unregister_port - Unregister an HSI port
370 * @port: The HSI port to unregister
371 */
372void hsi_port_unregister_clients(struct hsi_port *port)
373{
374 device_for_each_child(&port->device, NULL, hsi_remove_client);
375}
376EXPORT_SYMBOL_GPL(hsi_port_unregister_clients);
377
378/**
Carlos Chineaa056ab82010-04-16 19:01:02 +0300379 * hsi_unregister_controller - Unregister an HSI controller
380 * @hsi: The HSI controller to register
381 */
382void hsi_unregister_controller(struct hsi_controller *hsi)
383{
384 device_for_each_child(&hsi->device, NULL, hsi_remove_port);
385 device_unregister(&hsi->device);
386}
387EXPORT_SYMBOL_GPL(hsi_unregister_controller);
388
389/**
390 * hsi_register_controller - Register an HSI controller and its ports
391 * @hsi: The HSI controller to register
392 *
393 * Returns -errno on failure, 0 on success.
394 */
395int hsi_register_controller(struct hsi_controller *hsi)
396{
397 unsigned int i;
398 int err;
399
Carlos Chinea5a218ce2012-04-04 14:11:45 +0300400 err = device_add(&hsi->device);
Carlos Chineaa056ab82010-04-16 19:01:02 +0300401 if (err < 0)
402 return err;
403 for (i = 0; i < hsi->num_ports; i++) {
Carlos Chinea5a218ce2012-04-04 14:11:45 +0300404 hsi->port[i]->device.parent = &hsi->device;
Carlos Chinea5a218ce2012-04-04 14:11:45 +0300405 err = device_add(&hsi->port[i]->device);
Carlos Chineaa056ab82010-04-16 19:01:02 +0300406 if (err < 0)
407 goto out;
408 }
409 /* Populate HSI bus with HSI clients */
410 hsi_scan_board_info(hsi);
411
412 return 0;
413out:
Carlos Chinea5a218ce2012-04-04 14:11:45 +0300414 while (i-- > 0)
415 device_del(&hsi->port[i]->device);
416 device_del(&hsi->device);
Carlos Chineaa056ab82010-04-16 19:01:02 +0300417
418 return err;
419}
420EXPORT_SYMBOL_GPL(hsi_register_controller);
421
422/**
423 * hsi_register_client_driver - Register an HSI client to the HSI bus
424 * @drv: HSI client driver to register
425 *
426 * Returns -errno on failure, 0 on success.
427 */
428int hsi_register_client_driver(struct hsi_client_driver *drv)
429{
430 drv->driver.bus = &hsi_bus_type;
431
432 return driver_register(&drv->driver);
433}
434EXPORT_SYMBOL_GPL(hsi_register_client_driver);
435
436static inline int hsi_dummy_msg(struct hsi_msg *msg __maybe_unused)
437{
438 return 0;
439}
440
441static inline int hsi_dummy_cl(struct hsi_client *cl __maybe_unused)
442{
443 return 0;
444}
445
446/**
Carlos Chinea5a218ce2012-04-04 14:11:45 +0300447 * hsi_put_controller - Free an HSI controller
448 *
449 * @hsi: Pointer to the HSI controller to freed
450 *
451 * HSI controller drivers should only use this function if they need
452 * to free their allocated hsi_controller structures before a successful
453 * call to hsi_register_controller. Other use is not allowed.
454 */
455void hsi_put_controller(struct hsi_controller *hsi)
456{
457 unsigned int i;
458
459 if (!hsi)
460 return;
461
462 for (i = 0; i < hsi->num_ports; i++)
463 if (hsi->port && hsi->port[i])
464 put_device(&hsi->port[i]->device);
465 put_device(&hsi->device);
466}
467EXPORT_SYMBOL_GPL(hsi_put_controller);
468
469/**
Carlos Chineaa056ab82010-04-16 19:01:02 +0300470 * hsi_alloc_controller - Allocate an HSI controller and its ports
471 * @n_ports: Number of ports on the HSI controller
472 * @flags: Kernel allocation flags
473 *
474 * Return NULL on failure or a pointer to an hsi_controller on success.
475 */
476struct hsi_controller *hsi_alloc_controller(unsigned int n_ports, gfp_t flags)
477{
478 struct hsi_controller *hsi;
Carlos Chinea5a218ce2012-04-04 14:11:45 +0300479 struct hsi_port **port;
Carlos Chineaa056ab82010-04-16 19:01:02 +0300480 unsigned int i;
481
482 if (!n_ports)
483 return NULL;
484
Carlos Chineaa056ab82010-04-16 19:01:02 +0300485 hsi = kzalloc(sizeof(*hsi), flags);
486 if (!hsi)
Carlos Chinea5a218ce2012-04-04 14:11:45 +0300487 return NULL;
488 port = kzalloc(sizeof(*port)*n_ports, flags);
489 if (!port) {
490 kfree(hsi);
491 return NULL;
Carlos Chineaa056ab82010-04-16 19:01:02 +0300492 }
493 hsi->num_ports = n_ports;
494 hsi->port = port;
Carlos Chinea5a218ce2012-04-04 14:11:45 +0300495 hsi->device.release = hsi_controller_release;
496 device_initialize(&hsi->device);
497
498 for (i = 0; i < n_ports; i++) {
499 port[i] = kzalloc(sizeof(**port), flags);
500 if (port[i] == NULL)
501 goto out;
502 port[i]->num = i;
503 port[i]->async = hsi_dummy_msg;
504 port[i]->setup = hsi_dummy_cl;
505 port[i]->flush = hsi_dummy_cl;
506 port[i]->start_tx = hsi_dummy_cl;
507 port[i]->stop_tx = hsi_dummy_cl;
508 port[i]->release = hsi_dummy_cl;
509 mutex_init(&port[i]->lock);
Carlos Chineaec1c56f2012-04-11 10:55:53 +0300510 ATOMIC_INIT_NOTIFIER_HEAD(&port[i]->n_head);
Carlos Chinea5a218ce2012-04-04 14:11:45 +0300511 dev_set_name(&port[i]->device, "port%d", i);
512 hsi->port[i]->device.release = hsi_port_release;
513 device_initialize(&hsi->port[i]->device);
514 }
Carlos Chineaa056ab82010-04-16 19:01:02 +0300515
516 return hsi;
517out:
Carlos Chinea5a218ce2012-04-04 14:11:45 +0300518 hsi_put_controller(hsi);
Carlos Chineaa056ab82010-04-16 19:01:02 +0300519
520 return NULL;
521}
522EXPORT_SYMBOL_GPL(hsi_alloc_controller);
523
524/**
Carlos Chineaa056ab82010-04-16 19:01:02 +0300525 * hsi_free_msg - Free an HSI message
526 * @msg: Pointer to the HSI message
527 *
528 * Client is responsible to free the buffers pointed by the scatterlists.
529 */
530void hsi_free_msg(struct hsi_msg *msg)
531{
532 if (!msg)
533 return;
534 sg_free_table(&msg->sgt);
535 kfree(msg);
536}
537EXPORT_SYMBOL_GPL(hsi_free_msg);
538
539/**
540 * hsi_alloc_msg - Allocate an HSI message
541 * @nents: Number of memory entries
542 * @flags: Kernel allocation flags
543 *
544 * nents can be 0. This mainly makes sense for read transfer.
545 * In that case, HSI drivers will call the complete callback when
546 * there is data to be read without consuming it.
547 *
548 * Return NULL on failure or a pointer to an hsi_msg on success.
549 */
550struct hsi_msg *hsi_alloc_msg(unsigned int nents, gfp_t flags)
551{
552 struct hsi_msg *msg;
553 int err;
554
555 msg = kzalloc(sizeof(*msg), flags);
556 if (!msg)
557 return NULL;
558
559 if (!nents)
560 return msg;
561
562 err = sg_alloc_table(&msg->sgt, nents, flags);
563 if (unlikely(err)) {
564 kfree(msg);
565 msg = NULL;
566 }
567
568 return msg;
569}
570EXPORT_SYMBOL_GPL(hsi_alloc_msg);
571
572/**
573 * hsi_async - Submit an HSI transfer to the controller
574 * @cl: HSI client sending the transfer
575 * @msg: The HSI transfer passed to controller
576 *
577 * The HSI message must have the channel, ttype, complete and destructor
578 * fields set beforehand. If nents > 0 then the client has to initialize
579 * also the scatterlists to point to the buffers to write to or read from.
580 *
581 * HSI controllers relay on pre-allocated buffers from their clients and they
582 * do not allocate buffers on their own.
583 *
584 * Once the HSI message transfer finishes, the HSI controller calls the
585 * complete callback with the status and actual_len fields of the HSI message
586 * updated. The complete callback can be called before returning from
587 * hsi_async.
588 *
589 * Returns -errno on failure or 0 on success
590 */
591int hsi_async(struct hsi_client *cl, struct hsi_msg *msg)
592{
593 struct hsi_port *port = hsi_get_port(cl);
594
595 if (!hsi_port_claimed(cl))
596 return -EACCES;
597
598 WARN_ON_ONCE(!msg->destructor || !msg->complete);
599 msg->cl = cl;
600
601 return port->async(msg);
602}
603EXPORT_SYMBOL_GPL(hsi_async);
604
605/**
606 * hsi_claim_port - Claim the HSI client's port
607 * @cl: HSI client that wants to claim its port
608 * @share: Flag to indicate if the client wants to share the port or not.
609 *
610 * Returns -errno on failure, 0 on success.
611 */
612int hsi_claim_port(struct hsi_client *cl, unsigned int share)
613{
614 struct hsi_port *port = hsi_get_port(cl);
615 int err = 0;
616
617 mutex_lock(&port->lock);
618 if ((port->claimed) && (!port->shared || !share)) {
619 err = -EBUSY;
620 goto out;
621 }
622 if (!try_module_get(to_hsi_controller(port->device.parent)->owner)) {
623 err = -ENODEV;
624 goto out;
625 }
626 port->claimed++;
627 port->shared = !!share;
628 cl->pclaimed = 1;
629out:
630 mutex_unlock(&port->lock);
631
632 return err;
633}
634EXPORT_SYMBOL_GPL(hsi_claim_port);
635
636/**
637 * hsi_release_port - Release the HSI client's port
638 * @cl: HSI client which previously claimed its port
639 */
640void hsi_release_port(struct hsi_client *cl)
641{
642 struct hsi_port *port = hsi_get_port(cl);
643
644 mutex_lock(&port->lock);
645 /* Allow HW driver to do some cleanup */
646 port->release(cl);
647 if (cl->pclaimed)
648 port->claimed--;
649 BUG_ON(port->claimed < 0);
650 cl->pclaimed = 0;
651 if (!port->claimed)
652 port->shared = 0;
653 module_put(to_hsi_controller(port->device.parent)->owner);
654 mutex_unlock(&port->lock);
655}
656EXPORT_SYMBOL_GPL(hsi_release_port);
657
Carlos Chineaec1c56f2012-04-11 10:55:53 +0300658static int hsi_event_notifier_call(struct notifier_block *nb,
659 unsigned long event, void *data __maybe_unused)
Carlos Chineaa056ab82010-04-16 19:01:02 +0300660{
Carlos Chineaec1c56f2012-04-11 10:55:53 +0300661 struct hsi_client *cl = container_of(nb, struct hsi_client, nb);
662
663 (*cl->ehandler)(cl, event);
Carlos Chineaa056ab82010-04-16 19:01:02 +0300664
665 return 0;
666}
667
Carlos Chineaec1c56f2012-04-11 10:55:53 +0300668/**
669 * hsi_register_port_event - Register a client to receive port events
670 * @cl: HSI client that wants to receive port events
Randy Dunlap8eae5082013-03-01 11:11:47 -0800671 * @handler: Event handler callback
Carlos Chineaec1c56f2012-04-11 10:55:53 +0300672 *
673 * Clients should register a callback to be able to receive
674 * events from the ports. Registration should happen after
675 * claiming the port.
676 * The handler can be called in interrupt context.
677 *
678 * Returns -errno on error, or 0 on success.
679 */
680int hsi_register_port_event(struct hsi_client *cl,
681 void (*handler)(struct hsi_client *, unsigned long))
Carlos Chineaa056ab82010-04-16 19:01:02 +0300682{
Carlos Chineaec1c56f2012-04-11 10:55:53 +0300683 struct hsi_port *port = hsi_get_port(cl);
Carlos Chineaa056ab82010-04-16 19:01:02 +0300684
Carlos Chineaec1c56f2012-04-11 10:55:53 +0300685 if (!handler || cl->ehandler)
686 return -EINVAL;
687 if (!hsi_port_claimed(cl))
688 return -EACCES;
689 cl->ehandler = handler;
690 cl->nb.notifier_call = hsi_event_notifier_call;
691
692 return atomic_notifier_chain_register(&port->n_head, &cl->nb);
Carlos Chineaa056ab82010-04-16 19:01:02 +0300693}
Carlos Chineaec1c56f2012-04-11 10:55:53 +0300694EXPORT_SYMBOL_GPL(hsi_register_port_event);
Carlos Chineaa056ab82010-04-16 19:01:02 +0300695
Carlos Chineaec1c56f2012-04-11 10:55:53 +0300696/**
697 * hsi_unregister_port_event - Stop receiving port events for a client
698 * @cl: HSI client that wants to stop receiving port events
699 *
700 * Clients should call this function before releasing their associated
701 * port.
702 *
703 * Returns -errno on error, or 0 on success.
704 */
705int hsi_unregister_port_event(struct hsi_client *cl)
Carlos Chineaa056ab82010-04-16 19:01:02 +0300706{
Carlos Chineaec1c56f2012-04-11 10:55:53 +0300707 struct hsi_port *port = hsi_get_port(cl);
708 int err;
Carlos Chineaa056ab82010-04-16 19:01:02 +0300709
Carlos Chineaec1c56f2012-04-11 10:55:53 +0300710 WARN_ON(!hsi_port_claimed(cl));
Carlos Chineaa056ab82010-04-16 19:01:02 +0300711
Carlos Chineaec1c56f2012-04-11 10:55:53 +0300712 err = atomic_notifier_chain_unregister(&port->n_head, &cl->nb);
713 if (!err)
714 cl->ehandler = NULL;
715
716 return err;
Carlos Chineaa056ab82010-04-16 19:01:02 +0300717}
Carlos Chineaec1c56f2012-04-11 10:55:53 +0300718EXPORT_SYMBOL_GPL(hsi_unregister_port_event);
Carlos Chineaa056ab82010-04-16 19:01:02 +0300719
720/**
Sebastian Reichela2aa2472014-03-28 22:59:43 +0100721 * hsi_event - Notifies clients about port events
Carlos Chineaa056ab82010-04-16 19:01:02 +0300722 * @port: Port where the event occurred
723 * @event: The event type
724 *
725 * Clients should not be concerned about wake line behavior. However, due
726 * to a race condition in HSI HW protocol, clients need to be notified
727 * about wake line changes, so they can implement a workaround for it.
728 *
729 * Events:
730 * HSI_EVENT_START_RX - Incoming wake line high
731 * HSI_EVENT_STOP_RX - Incoming wake line down
Carlos Chineaec1c56f2012-04-11 10:55:53 +0300732 *
733 * Returns -errno on error, or 0 on success.
Carlos Chineaa056ab82010-04-16 19:01:02 +0300734 */
Carlos Chineaec1c56f2012-04-11 10:55:53 +0300735int hsi_event(struct hsi_port *port, unsigned long event)
Carlos Chineaa056ab82010-04-16 19:01:02 +0300736{
Carlos Chineaec1c56f2012-04-11 10:55:53 +0300737 return atomic_notifier_call_chain(&port->n_head, event, NULL);
Carlos Chineaa056ab82010-04-16 19:01:02 +0300738}
739EXPORT_SYMBOL_GPL(hsi_event);
740
Sebastian Reichela088cf12014-03-28 22:48:23 +0100741/**
742 * hsi_get_channel_id_by_name - acquire channel id by channel name
743 * @cl: HSI client, which uses the channel
744 * @name: name the channel is known under
745 *
746 * Clients can call this function to get the hsi channel ids similar to
747 * requesting IRQs or GPIOs by name. This function assumes the same
748 * channel configuration is used for RX and TX.
749 *
750 * Returns -errno on error or channel id on success.
751 */
752int hsi_get_channel_id_by_name(struct hsi_client *cl, char *name)
753{
754 int i;
755
756 if (!cl->rx_cfg.channels)
757 return -ENOENT;
758
759 for (i = 0; i < cl->rx_cfg.num_channels; i++)
760 if (!strcmp(cl->rx_cfg.channels[i].name, name))
761 return cl->rx_cfg.channels[i].id;
762
763 return -ENXIO;
764}
765EXPORT_SYMBOL_GPL(hsi_get_channel_id_by_name);
766
Carlos Chineaa056ab82010-04-16 19:01:02 +0300767static int __init hsi_init(void)
768{
769 return bus_register(&hsi_bus_type);
770}
771postcore_initcall(hsi_init);
772
773static void __exit hsi_exit(void)
774{
775 bus_unregister(&hsi_bus_type);
776}
777module_exit(hsi_exit);
778
779MODULE_AUTHOR("Carlos Chinea <carlos.chinea@nokia.com>");
780MODULE_DESCRIPTION("High-speed Synchronous Serial Interface (HSI) framework");
781MODULE_LICENSE("GPL v2");