1// SPDX-License-Identifier: GPL-2.0
2/*
3 * HID class driver for the Greybus.
4 *
5 * Copyright 2014 Google Inc.
6 * Copyright 2014 Linaro Ltd.
7 */
8
9#include <linux/bitops.h>
10#include <linux/hid.h>
11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/mutex.h>
14#include <linux/slab.h>
15#include <linux/greybus.h>
16
17/* Greybus HID device's structure */
18struct gb_hid {
19 struct gb_bundle *bundle;
20 struct gb_connection *connection;
21
22 struct hid_device *hid;
23 struct gb_hid_desc_response hdesc;
24
25 unsigned long flags;
26#define GB_HID_STARTED 0x01
27#define GB_HID_READ_PENDING 0x04
28
29 unsigned int bufsize;
30 char *inbuf;
31};
32
33/* Routines to get controller's information over greybus */
34
35/* Operations performed on greybus */
36static int gb_hid_get_desc(struct gb_hid *ghid)
37{
38 return gb_operation_sync(connection: ghid->connection, GB_HID_TYPE_GET_DESC, NULL,
39 request_size: 0, response: &ghid->hdesc, response_size: sizeof(ghid->hdesc));
40}
41
42static int gb_hid_get_report_desc(struct gb_hid *ghid, char *rdesc)
43{
44 int ret;
45
46 ret = gb_pm_runtime_get_sync(bundle: ghid->bundle);
47 if (ret)
48 return ret;
49
50 ret = gb_operation_sync(connection: ghid->connection, GB_HID_TYPE_GET_REPORT_DESC,
51 NULL, request_size: 0, response: rdesc,
52 le16_to_cpu(ghid->hdesc.wReportDescLength));
53
54 gb_pm_runtime_put_autosuspend(bundle: ghid->bundle);
55
56 return ret;
57}
58
59static int gb_hid_set_power(struct gb_hid *ghid, int type)
60{
61 int ret;
62
63 ret = gb_pm_runtime_get_sync(bundle: ghid->bundle);
64 if (ret)
65 return ret;
66
67 ret = gb_operation_sync(connection: ghid->connection, type, NULL, request_size: 0, NULL, response_size: 0);
68
69 gb_pm_runtime_put_autosuspend(bundle: ghid->bundle);
70
71 return ret;
72}
73
74static int gb_hid_get_report(struct gb_hid *ghid, u8 report_type, u8 report_id,
75 unsigned char *buf, int len)
76{
77 struct gb_hid_get_report_request request;
78 int ret;
79
80 ret = gb_pm_runtime_get_sync(bundle: ghid->bundle);
81 if (ret)
82 return ret;
83
84 request.report_type = report_type;
85 request.report_id = report_id;
86
87 ret = gb_operation_sync(connection: ghid->connection, GB_HID_TYPE_GET_REPORT,
88 request: &request, request_size: sizeof(request), response: buf, response_size: len);
89
90 gb_pm_runtime_put_autosuspend(bundle: ghid->bundle);
91
92 return ret;
93}
94
95static int gb_hid_set_report(struct gb_hid *ghid, u8 report_type, u8 report_id,
96 unsigned char *buf, int len)
97{
98 struct gb_hid_set_report_request *request;
99 struct gb_operation *operation;
100 int ret, size = sizeof(*request) + len - 1;
101
102 ret = gb_pm_runtime_get_sync(bundle: ghid->bundle);
103 if (ret)
104 return ret;
105
106 operation = gb_operation_create(connection: ghid->connection,
107 GB_HID_TYPE_SET_REPORT, request_size: size, response_size: 0,
108 GFP_KERNEL);
109 if (!operation) {
110 gb_pm_runtime_put_autosuspend(bundle: ghid->bundle);
111 return -ENOMEM;
112 }
113
114 request = operation->request->payload;
115 request->report_type = report_type;
116 request->report_id = report_id;
117 memcpy(request->report, buf, len);
118
119 ret = gb_operation_request_send_sync(operation);
120 if (ret) {
121 dev_err(&operation->connection->bundle->dev,
122 "failed to set report: %d\n", ret);
123 } else {
124 ret = len;
125 }
126
127 gb_operation_put(operation);
128 gb_pm_runtime_put_autosuspend(bundle: ghid->bundle);
129
130 return ret;
131}
132
133static int gb_hid_request_handler(struct gb_operation *op)
134{
135 struct gb_connection *connection = op->connection;
136 struct gb_hid *ghid = gb_connection_get_data(connection);
137 struct gb_hid_input_report_request *request = op->request->payload;
138
139 if (op->type != GB_HID_TYPE_IRQ_EVENT) {
140 dev_err(&connection->bundle->dev,
141 "unsupported unsolicited request\n");
142 return -EINVAL;
143 }
144
145 if (test_bit(GB_HID_STARTED, &ghid->flags))
146 hid_input_report(hid: ghid->hid, type: HID_INPUT_REPORT,
147 data: request->report, size: op->request->payload_size, interrupt: 1);
148
149 return 0;
150}
151
152static int gb_hid_report_len(struct hid_report *report)
153{
154 return ((report->size - 1) >> 3) + 1 +
155 report->device->report_enum[report->type].numbered;
156}
157
158static void gb_hid_find_max_report(struct hid_device *hid, unsigned int type,
159 unsigned int *max)
160{
161 struct hid_report *report;
162 unsigned int size;
163
164 list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
165 size = gb_hid_report_len(report);
166 if (*max < size)
167 *max = size;
168 }
169}
170
171static void gb_hid_free_buffers(struct gb_hid *ghid)
172{
173 kfree(objp: ghid->inbuf);
174 ghid->inbuf = NULL;
175 ghid->bufsize = 0;
176}
177
178static int gb_hid_alloc_buffers(struct gb_hid *ghid, size_t bufsize)
179{
180 ghid->inbuf = kzalloc(size: bufsize, GFP_KERNEL);
181 if (!ghid->inbuf)
182 return -ENOMEM;
183
184 ghid->bufsize = bufsize;
185
186 return 0;
187}
188
189/* Routines dealing with reports */
190static void gb_hid_init_report(struct gb_hid *ghid, struct hid_report *report)
191{
192 unsigned int size;
193
194 size = gb_hid_report_len(report);
195 if (gb_hid_get_report(ghid, report_type: report->type, report_id: report->id, buf: ghid->inbuf,
196 len: size))
197 return;
198
199 /*
200 * hid->driver_lock is held as we are in probe function,
201 * we just need to setup the input fields, so using
202 * hid_report_raw_event is safe.
203 */
204 hid_report_raw_event(hid: ghid->hid, type: report->type, data: ghid->inbuf, size, interrupt: 1);
205}
206
207static void gb_hid_init_reports(struct gb_hid *ghid)
208{
209 struct hid_device *hid = ghid->hid;
210 struct hid_report *report;
211
212 list_for_each_entry(report,
213 &hid->report_enum[HID_INPUT_REPORT].report_list,
214 list)
215 gb_hid_init_report(ghid, report);
216
217 list_for_each_entry(report,
218 &hid->report_enum[HID_FEATURE_REPORT].report_list,
219 list)
220 gb_hid_init_report(ghid, report);
221}
222
223static int __gb_hid_get_raw_report(struct hid_device *hid,
224 unsigned char report_number, __u8 *buf, size_t count,
225 unsigned char report_type)
226{
227 struct gb_hid *ghid = hid->driver_data;
228 int ret;
229
230 if (report_type == HID_OUTPUT_REPORT)
231 return -EINVAL;
232
233 ret = gb_hid_get_report(ghid, report_type, report_id: report_number, buf, len: count);
234 if (!ret)
235 ret = count;
236
237 return ret;
238}
239
240static int __gb_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
241 size_t len, unsigned char report_type)
242{
243 struct gb_hid *ghid = hid->driver_data;
244 int report_id = buf[0];
245 int ret;
246
247 if (report_type == HID_INPUT_REPORT)
248 return -EINVAL;
249
250 if (report_id) {
251 buf++;
252 len--;
253 }
254
255 ret = gb_hid_set_report(ghid, report_type, report_id, buf, len);
256 if (report_id && ret >= 0)
257 ret++; /* add report_id to the number of transferred bytes */
258
259 return 0;
260}
261
262static int gb_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
263 __u8 *buf, size_t len, unsigned char rtype,
264 int reqtype)
265{
266 switch (reqtype) {
267 case HID_REQ_GET_REPORT:
268 return __gb_hid_get_raw_report(hid, report_number: reportnum, buf, count: len, report_type: rtype);
269 case HID_REQ_SET_REPORT:
270 if (buf[0] != reportnum)
271 return -EINVAL;
272 return __gb_hid_output_raw_report(hid, buf, len, report_type: rtype);
273 default:
274 return -EIO;
275 }
276}
277
278/* HID Callbacks */
279static int gb_hid_parse(struct hid_device *hid)
280{
281 struct gb_hid *ghid = hid->driver_data;
282 unsigned int rsize;
283 char *rdesc;
284 int ret;
285
286 rsize = le16_to_cpu(ghid->hdesc.wReportDescLength);
287 if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
288 dbg_hid("weird size of report descriptor (%u)\n", rsize);
289 return -EINVAL;
290 }
291
292 rdesc = kzalloc(size: rsize, GFP_KERNEL);
293 if (!rdesc)
294 return -ENOMEM;
295
296 ret = gb_hid_get_report_desc(ghid, rdesc);
297 if (ret) {
298 hid_err(hid, "reading report descriptor failed\n");
299 goto free_rdesc;
300 }
301
302 ret = hid_parse_report(hid, start: rdesc, size: rsize);
303 if (ret)
304 dbg_hid("parsing report descriptor failed\n");
305
306free_rdesc:
307 kfree(objp: rdesc);
308
309 return ret;
310}
311
312static int gb_hid_start(struct hid_device *hid)
313{
314 struct gb_hid *ghid = hid->driver_data;
315 unsigned int bufsize = HID_MIN_BUFFER_SIZE;
316 int ret;
317
318 gb_hid_find_max_report(hid, type: HID_INPUT_REPORT, max: &bufsize);
319 gb_hid_find_max_report(hid, type: HID_OUTPUT_REPORT, max: &bufsize);
320 gb_hid_find_max_report(hid, type: HID_FEATURE_REPORT, max: &bufsize);
321
322 if (bufsize > HID_MAX_BUFFER_SIZE)
323 bufsize = HID_MAX_BUFFER_SIZE;
324
325 ret = gb_hid_alloc_buffers(ghid, bufsize);
326 if (ret)
327 return ret;
328
329 if (!(hid->quirks & HID_QUIRK_NO_INIT_REPORTS))
330 gb_hid_init_reports(ghid);
331
332 return 0;
333}
334
335static void gb_hid_stop(struct hid_device *hid)
336{
337 struct gb_hid *ghid = hid->driver_data;
338
339 gb_hid_free_buffers(ghid);
340}
341
342static int gb_hid_open(struct hid_device *hid)
343{
344 struct gb_hid *ghid = hid->driver_data;
345 int ret;
346
347 ret = gb_hid_set_power(ghid, GB_HID_TYPE_PWR_ON);
348 if (ret < 0)
349 return ret;
350
351 set_bit(GB_HID_STARTED, addr: &ghid->flags);
352 return 0;
353}
354
355static void gb_hid_close(struct hid_device *hid)
356{
357 struct gb_hid *ghid = hid->driver_data;
358 int ret;
359
360 clear_bit(GB_HID_STARTED, addr: &ghid->flags);
361
362 /* Save some power */
363 ret = gb_hid_set_power(ghid, GB_HID_TYPE_PWR_OFF);
364 if (ret)
365 dev_err(&ghid->connection->bundle->dev,
366 "failed to power off (%d)\n", ret);
367}
368
369static int gb_hid_power(struct hid_device *hid, int lvl)
370{
371 struct gb_hid *ghid = hid->driver_data;
372
373 switch (lvl) {
374 case PM_HINT_FULLON:
375 return gb_hid_set_power(ghid, GB_HID_TYPE_PWR_ON);
376 case PM_HINT_NORMAL:
377 return gb_hid_set_power(ghid, GB_HID_TYPE_PWR_OFF);
378 }
379
380 return 0;
381}
382
383/* HID structure to pass callbacks */
384static const struct hid_ll_driver gb_hid_ll_driver = {
385 .parse = gb_hid_parse,
386 .start = gb_hid_start,
387 .stop = gb_hid_stop,
388 .open = gb_hid_open,
389 .close = gb_hid_close,
390 .power = gb_hid_power,
391 .raw_request = gb_hid_raw_request,
392};
393
394static int gb_hid_init(struct gb_hid *ghid)
395{
396 struct hid_device *hid = ghid->hid;
397 int ret;
398
399 ret = gb_hid_get_desc(ghid);
400 if (ret)
401 return ret;
402
403 hid->version = le16_to_cpu(ghid->hdesc.bcdHID);
404 hid->vendor = le16_to_cpu(ghid->hdesc.wVendorID);
405 hid->product = le16_to_cpu(ghid->hdesc.wProductID);
406 hid->country = ghid->hdesc.bCountryCode;
407
408 hid->driver_data = ghid;
409 hid->ll_driver = &gb_hid_ll_driver;
410 hid->dev.parent = &ghid->connection->bundle->dev;
411// hid->bus = BUS_GREYBUS; /* Need a bustype for GREYBUS in <linux/input.h> */
412
413 /* Set HID device's name */
414 snprintf(buf: hid->name, size: sizeof(hid->name), fmt: "%s %04X:%04X",
415 dev_name(dev: &ghid->connection->bundle->dev),
416 hid->vendor, hid->product);
417
418 return 0;
419}
420
421static int gb_hid_probe(struct gb_bundle *bundle,
422 const struct greybus_bundle_id *id)
423{
424 struct greybus_descriptor_cport *cport_desc;
425 struct gb_connection *connection;
426 struct hid_device *hid;
427 struct gb_hid *ghid;
428 int ret;
429
430 if (bundle->num_cports != 1)
431 return -ENODEV;
432
433 cport_desc = &bundle->cport_desc[0];
434 if (cport_desc->protocol_id != GREYBUS_PROTOCOL_HID)
435 return -ENODEV;
436
437 ghid = kzalloc(size: sizeof(*ghid), GFP_KERNEL);
438 if (!ghid)
439 return -ENOMEM;
440
441 connection = gb_connection_create(bundle, le16_to_cpu(cport_desc->id),
442 handler: gb_hid_request_handler);
443 if (IS_ERR(ptr: connection)) {
444 ret = PTR_ERR(ptr: connection);
445 goto err_free_ghid;
446 }
447
448 gb_connection_set_data(connection, data: ghid);
449 ghid->connection = connection;
450
451 hid = hid_allocate_device();
452 if (IS_ERR(ptr: hid)) {
453 ret = PTR_ERR(ptr: hid);
454 goto err_connection_destroy;
455 }
456
457 ghid->hid = hid;
458 ghid->bundle = bundle;
459
460 greybus_set_drvdata(bundle, data: ghid);
461
462 ret = gb_connection_enable(connection);
463 if (ret)
464 goto err_destroy_hid;
465
466 ret = gb_hid_init(ghid);
467 if (ret)
468 goto err_connection_disable;
469
470 ret = hid_add_device(hid);
471 if (ret) {
472 hid_err(hid, "can't add hid device: %d\n", ret);
473 goto err_connection_disable;
474 }
475
476 gb_pm_runtime_put_autosuspend(bundle);
477
478 return 0;
479
480err_connection_disable:
481 gb_connection_disable(connection);
482err_destroy_hid:
483 hid_destroy_device(hid);
484err_connection_destroy:
485 gb_connection_destroy(connection);
486err_free_ghid:
487 kfree(objp: ghid);
488
489 return ret;
490}
491
492static void gb_hid_disconnect(struct gb_bundle *bundle)
493{
494 struct gb_hid *ghid = greybus_get_drvdata(bundle);
495
496 if (gb_pm_runtime_get_sync(bundle))
497 gb_pm_runtime_get_noresume(bundle);
498
499 hid_destroy_device(ghid->hid);
500 gb_connection_disable(connection: ghid->connection);
501 gb_connection_destroy(connection: ghid->connection);
502 kfree(objp: ghid);
503}
504
505static const struct greybus_bundle_id gb_hid_id_table[] = {
506 { GREYBUS_DEVICE_CLASS(GREYBUS_CLASS_HID) },
507 { }
508};
509MODULE_DEVICE_TABLE(greybus, gb_hid_id_table);
510
511static struct greybus_driver gb_hid_driver = {
512 .name = "hid",
513 .probe = gb_hid_probe,
514 .disconnect = gb_hid_disconnect,
515 .id_table = gb_hid_id_table,
516};
517module_greybus_driver(gb_hid_driver);
518
519MODULE_LICENSE("GPL v2");
520

source code of linux/drivers/staging/greybus/hid.c