1 /*
2 * Bluetooth HCI serdev driver lib
3 *
4 * Copyright (C) 2017 Linaro, Ltd., Rob Herring <robh@kernel.org>
5 *
6 * Based on hci_ldisc.c:
7 *
8 * Copyright (C) 2000-2001 Qualcomm Incorporated
9 * Copyright (C) 2002-2003 Maxim Krasnyansky <maxk@qualcomm.com>
10 * Copyright (C) 2004-2005 Marcel Holtmann <marcel@holtmann.org>
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
16 *
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
21 *
22 */
23
24 #include <linux/kernel.h>
25 #include <linux/types.h>
26 #include <linux/serdev.h>
27 #include <linux/skbuff.h>
28
29 #include <net/bluetooth/bluetooth.h>
30 #include <net/bluetooth/hci_core.h>
31
32 #include "hci_uart.h"
33
34 static struct serdev_device_ops hci_serdev_client_ops;
35
hci_uart_tx_complete(struct hci_uart * hu,int pkt_type)36 static inline void hci_uart_tx_complete(struct hci_uart *hu, int pkt_type)
37 {
38 struct hci_dev *hdev = hu->hdev;
39
40 /* Update HCI stat counters */
41 switch (pkt_type) {
42 case HCI_COMMAND_PKT:
43 hdev->stat.cmd_tx++;
44 break;
45
46 case HCI_ACLDATA_PKT:
47 hdev->stat.acl_tx++;
48 break;
49
50 case HCI_SCODATA_PKT:
51 hdev->stat.sco_tx++;
52 break;
53 }
54 }
55
hci_uart_dequeue(struct hci_uart * hu)56 static inline struct sk_buff *hci_uart_dequeue(struct hci_uart *hu)
57 {
58 struct sk_buff *skb = hu->tx_skb;
59
60 if (!skb)
61 skb = hu->proto->dequeue(hu);
62 else
63 hu->tx_skb = NULL;
64
65 return skb;
66 }
67
hci_uart_write_work(struct work_struct * work)68 static void hci_uart_write_work(struct work_struct *work)
69 {
70 struct hci_uart *hu = container_of(work, struct hci_uart, write_work);
71 struct serdev_device *serdev = hu->serdev;
72 struct hci_dev *hdev = hu->hdev;
73 struct sk_buff *skb;
74
75 /* REVISIT:
76 * should we cope with bad skbs or ->write() returning an error value?
77 */
78 do {
79 clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
80
81 while ((skb = hci_uart_dequeue(hu))) {
82 int len;
83
84 len = serdev_device_write_buf(serdev,
85 skb->data, skb->len);
86 hdev->stat.byte_tx += len;
87
88 skb_pull(skb, len);
89 if (skb->len) {
90 hu->tx_skb = skb;
91 break;
92 }
93
94 hci_uart_tx_complete(hu, hci_skb_pkt_type(skb));
95 kfree_skb(skb);
96 }
97 } while(test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state));
98
99 clear_bit(HCI_UART_SENDING, &hu->tx_state);
100 }
101
102 /* ------- Interface to HCI layer ------ */
103
104 /* Reset device */
hci_uart_flush(struct hci_dev * hdev)105 static int hci_uart_flush(struct hci_dev *hdev)
106 {
107 struct hci_uart *hu = hci_get_drvdata(hdev);
108
109 BT_DBG("hdev %p serdev %p", hdev, hu->serdev);
110
111 if (hu->tx_skb) {
112 kfree_skb(hu->tx_skb); hu->tx_skb = NULL;
113 }
114
115 /* Flush any pending characters in the driver and discipline. */
116 serdev_device_write_flush(hu->serdev);
117
118 if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
119 hu->proto->flush(hu);
120
121 return 0;
122 }
123
124 /* Initialize device */
hci_uart_open(struct hci_dev * hdev)125 static int hci_uart_open(struct hci_dev *hdev)
126 {
127 BT_DBG("%s %p", hdev->name, hdev);
128
129 /* Undo clearing this from hci_uart_close() */
130 hdev->flush = hci_uart_flush;
131
132 return 0;
133 }
134
135 /* Close device */
hci_uart_close(struct hci_dev * hdev)136 static int hci_uart_close(struct hci_dev *hdev)
137 {
138 BT_DBG("hdev %p", hdev);
139
140 hci_uart_flush(hdev);
141 hdev->flush = NULL;
142
143 return 0;
144 }
145
146 /* Send frames from HCI layer */
hci_uart_send_frame(struct hci_dev * hdev,struct sk_buff * skb)147 static int hci_uart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
148 {
149 struct hci_uart *hu = hci_get_drvdata(hdev);
150
151 BT_DBG("%s: type %d len %d", hdev->name, hci_skb_pkt_type(skb),
152 skb->len);
153
154 hu->proto->enqueue(hu, skb);
155
156 hci_uart_tx_wakeup(hu);
157
158 return 0;
159 }
160
hci_uart_setup(struct hci_dev * hdev)161 static int hci_uart_setup(struct hci_dev *hdev)
162 {
163 struct hci_uart *hu = hci_get_drvdata(hdev);
164 struct hci_rp_read_local_version *ver;
165 struct sk_buff *skb;
166 unsigned int speed;
167 int err;
168
169 /* Init speed if any */
170 if (hu->init_speed)
171 speed = hu->init_speed;
172 else if (hu->proto->init_speed)
173 speed = hu->proto->init_speed;
174 else
175 speed = 0;
176
177 if (speed)
178 serdev_device_set_baudrate(hu->serdev, speed);
179
180 /* Operational speed if any */
181 if (hu->oper_speed)
182 speed = hu->oper_speed;
183 else if (hu->proto->oper_speed)
184 speed = hu->proto->oper_speed;
185 else
186 speed = 0;
187
188 if (hu->proto->set_baudrate && speed) {
189 err = hu->proto->set_baudrate(hu, speed);
190 if (err)
191 bt_dev_err(hdev, "Failed to set baudrate");
192 else
193 serdev_device_set_baudrate(hu->serdev, speed);
194 }
195
196 if (hu->proto->setup)
197 return hu->proto->setup(hu);
198
199 if (!test_bit(HCI_UART_VND_DETECT, &hu->hdev_flags))
200 return 0;
201
202 skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
203 HCI_INIT_TIMEOUT);
204 if (IS_ERR(skb)) {
205 bt_dev_err(hdev, "Reading local version info failed (%ld)",
206 PTR_ERR(skb));
207 return 0;
208 }
209
210 if (skb->len != sizeof(*ver))
211 bt_dev_err(hdev, "Event length mismatch for version info");
212
213 kfree_skb(skb);
214 return 0;
215 }
216
217 /** hci_uart_write_wakeup - transmit buffer wakeup
218 * @serdev: serial device
219 *
220 * This function is called by the serdev framework when it accepts
221 * more data being sent.
222 */
hci_uart_write_wakeup(struct serdev_device * serdev)223 static void hci_uart_write_wakeup(struct serdev_device *serdev)
224 {
225 struct hci_uart *hu = serdev_device_get_drvdata(serdev);
226
227 BT_DBG("");
228
229 if (!hu || serdev != hu->serdev) {
230 WARN_ON(1);
231 return;
232 }
233
234 if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
235 hci_uart_tx_wakeup(hu);
236 }
237
238 /** hci_uart_receive_buf - receive buffer wakeup
239 * @serdev: serial device
240 * @data: pointer to received data
241 * @count: count of received data in bytes
242 *
243 * This function is called by the serdev framework when it received data
244 * in the RX buffer.
245 *
246 * Return: number of processed bytes
247 */
hci_uart_receive_buf(struct serdev_device * serdev,const u8 * data,size_t count)248 static int hci_uart_receive_buf(struct serdev_device *serdev, const u8 *data,
249 size_t count)
250 {
251 struct hci_uart *hu = serdev_device_get_drvdata(serdev);
252
253 if (!hu || serdev != hu->serdev) {
254 WARN_ON(1);
255 return 0;
256 }
257
258 if (!test_bit(HCI_UART_PROTO_READY, &hu->flags))
259 return 0;
260
261 /* It does not need a lock here as it is already protected by a mutex in
262 * tty caller
263 */
264 hu->proto->recv(hu, data, count);
265
266 if (hu->hdev)
267 hu->hdev->stat.byte_rx += count;
268
269 return count;
270 }
271
272 static struct serdev_device_ops hci_serdev_client_ops = {
273 .receive_buf = hci_uart_receive_buf,
274 .write_wakeup = hci_uart_write_wakeup,
275 };
276
hci_uart_register_device(struct hci_uart * hu,const struct hci_uart_proto * p)277 int hci_uart_register_device(struct hci_uart *hu,
278 const struct hci_uart_proto *p)
279 {
280 int err;
281 struct hci_dev *hdev;
282
283 BT_DBG("");
284
285 serdev_device_set_client_ops(hu->serdev, &hci_serdev_client_ops);
286
287 err = serdev_device_open(hu->serdev);
288 if (err)
289 return err;
290
291 percpu_init_rwsem(&hu->proto_lock);
292
293 err = p->open(hu);
294 if (err)
295 goto err_open;
296
297 hu->proto = p;
298 set_bit(HCI_UART_PROTO_READY, &hu->flags);
299
300 /* Initialize and register HCI device */
301 hdev = hci_alloc_dev();
302 if (!hdev) {
303 BT_ERR("Can't allocate HCI device");
304 err = -ENOMEM;
305 goto err_alloc;
306 }
307
308 hu->hdev = hdev;
309
310 hdev->bus = HCI_UART;
311 hci_set_drvdata(hdev, hu);
312
313 INIT_WORK(&hu->init_ready, hci_uart_init_work);
314 INIT_WORK(&hu->write_work, hci_uart_write_work);
315
316 /* Only when vendor specific setup callback is provided, consider
317 * the manufacturer information valid. This avoids filling in the
318 * value for Ericsson when nothing is specified.
319 */
320 if (hu->proto->setup)
321 hdev->manufacturer = hu->proto->manufacturer;
322
323 hdev->open = hci_uart_open;
324 hdev->close = hci_uart_close;
325 hdev->flush = hci_uart_flush;
326 hdev->send = hci_uart_send_frame;
327 hdev->setup = hci_uart_setup;
328 SET_HCIDEV_DEV(hdev, &hu->serdev->dev);
329
330 if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
331 set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
332
333 if (test_bit(HCI_UART_EXT_CONFIG, &hu->hdev_flags))
334 set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
335
336 if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
337 set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
338
339 if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
340 hdev->dev_type = HCI_AMP;
341 else
342 hdev->dev_type = HCI_PRIMARY;
343
344 if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
345 return 0;
346
347 if (hci_register_dev(hdev) < 0) {
348 BT_ERR("Can't register HCI device");
349 err = -ENODEV;
350 goto err_register;
351 }
352
353 set_bit(HCI_UART_REGISTERED, &hu->flags);
354
355 return 0;
356
357 err_register:
358 hci_free_dev(hdev);
359 err_alloc:
360 clear_bit(HCI_UART_PROTO_READY, &hu->flags);
361 p->close(hu);
362 err_open:
363 serdev_device_close(hu->serdev);
364 return err;
365 }
366 EXPORT_SYMBOL_GPL(hci_uart_register_device);
367
hci_uart_unregister_device(struct hci_uart * hu)368 void hci_uart_unregister_device(struct hci_uart *hu)
369 {
370 struct hci_dev *hdev = hu->hdev;
371
372 clear_bit(HCI_UART_PROTO_READY, &hu->flags);
373
374 cancel_work_sync(&hu->init_ready);
375 if (test_bit(HCI_UART_REGISTERED, &hu->flags))
376 hci_unregister_dev(hdev);
377 hci_free_dev(hdev);
378
379 cancel_work_sync(&hu->write_work);
380
381 hu->proto->close(hu);
382 serdev_device_close(hu->serdev);
383 }
384 EXPORT_SYMBOL_GPL(hci_uart_unregister_device);
385