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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Bluetooth HCI serdev driver lib
4 *
5 * Copyright (C) 2017 Linaro, Ltd., Rob Herring <robh@kernel.org>
6 *
7 * Based on hci_ldisc.c:
8 *
9 * Copyright (C) 2000-2001 Qualcomm Incorporated
10 * Copyright (C) 2002-2003 Maxim Krasnyansky <maxk@qualcomm.com>
11 * Copyright (C) 2004-2005 Marcel Holtmann <marcel@holtmann.org>
12 */
13
14#include <linux/kernel.h>
15#include <linux/types.h>
16#include <linux/serdev.h>
17#include <linux/skbuff.h>
18
19#include <net/bluetooth/bluetooth.h>
20#include <net/bluetooth/hci_core.h>
21
22#include "hci_uart.h"
23
24static inline void hci_uart_tx_complete(struct hci_uart *hu, int pkt_type)
25{
26 struct hci_dev *hdev = hu->hdev;
27
28 /* Update HCI stat counters */
29 switch (pkt_type) {
30 case HCI_COMMAND_PKT:
31 hdev->stat.cmd_tx++;
32 break;
33
34 case HCI_ACLDATA_PKT:
35 hdev->stat.acl_tx++;
36 break;
37
38 case HCI_SCODATA_PKT:
39 hdev->stat.sco_tx++;
40 break;
41 }
42}
43
44static inline struct sk_buff *hci_uart_dequeue(struct hci_uart *hu)
45{
46 struct sk_buff *skb = hu->tx_skb;
47
48 if (!skb) {
49 if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
50 skb = hu->proto->dequeue(hu);
51 } else
52 hu->tx_skb = NULL;
53
54 return skb;
55}
56
57static void hci_uart_write_work(struct work_struct *work)
58{
59 struct hci_uart *hu = container_of(work, struct hci_uart, write_work);
60 struct serdev_device *serdev = hu->serdev;
61 struct hci_dev *hdev = hu->hdev;
62 struct sk_buff *skb;
63
64 /* REVISIT:
65 * should we cope with bad skbs or ->write() returning an error value?
66 */
67 do {
68 clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
69
70 while ((skb = hci_uart_dequeue(hu))) {
71 int len;
72
73 len = serdev_device_write_buf(serdev,
74 skb->data, skb->len);
75 hdev->stat.byte_tx += len;
76
77 skb_pull(skb, len);
78 if (skb->len) {
79 hu->tx_skb = skb;
80 break;
81 }
82
83 hci_uart_tx_complete(hu, hci_skb_pkt_type(skb));
84 kfree_skb(skb);
85 }
86 } while (test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state));
87
88 clear_bit(HCI_UART_SENDING, &hu->tx_state);
89}
90
91/* ------- Interface to HCI layer ------ */
92
93/* Reset device */
94static int hci_uart_flush(struct hci_dev *hdev)
95{
96 struct hci_uart *hu = hci_get_drvdata(hdev);
97
98 BT_DBG("hdev %p serdev %p", hdev, hu->serdev);
99
100 if (hu->tx_skb) {
101 kfree_skb(hu->tx_skb); hu->tx_skb = NULL;
102 }
103
104 /* Flush any pending characters in the driver and discipline. */
105 serdev_device_write_flush(hu->serdev);
106
107 if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
108 hu->proto->flush(hu);
109
110 return 0;
111}
112
113/* Initialize device */
114static int hci_uart_open(struct hci_dev *hdev)
115{
116 BT_DBG("%s %p", hdev->name, hdev);
117
118 /* Undo clearing this from hci_uart_close() */
119 hdev->flush = hci_uart_flush;
120
121 return 0;
122}
123
124/* Close device */
125static int hci_uart_close(struct hci_dev *hdev)
126{
127 BT_DBG("hdev %p", hdev);
128
129 hci_uart_flush(hdev);
130 hdev->flush = NULL;
131
132 return 0;
133}
134
135/* Send frames from HCI layer */
136static int hci_uart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
137{
138 struct hci_uart *hu = hci_get_drvdata(hdev);
139
140 BT_DBG("%s: type %d len %d", hdev->name, hci_skb_pkt_type(skb),
141 skb->len);
142
143 hu->proto->enqueue(hu, skb);
144
145 hci_uart_tx_wakeup(hu);
146
147 return 0;
148}
149
150static int hci_uart_setup(struct hci_dev *hdev)
151{
152 struct hci_uart *hu = hci_get_drvdata(hdev);
153 struct hci_rp_read_local_version *ver;
154 struct sk_buff *skb;
155 unsigned int speed;
156 int err;
157
158 /* Init speed if any */
159 if (hu->init_speed)
160 speed = hu->init_speed;
161 else if (hu->proto->init_speed)
162 speed = hu->proto->init_speed;
163 else
164 speed = 0;
165
166 if (speed)
167 serdev_device_set_baudrate(hu->serdev, speed);
168
169 /* Operational speed if any */
170 if (hu->oper_speed)
171 speed = hu->oper_speed;
172 else if (hu->proto->oper_speed)
173 speed = hu->proto->oper_speed;
174 else
175 speed = 0;
176
177 if (hu->proto->set_baudrate && speed) {
178 err = hu->proto->set_baudrate(hu, speed);
179 if (err)
180 bt_dev_err(hdev, "Failed to set baudrate");
181 else
182 serdev_device_set_baudrate(hu->serdev, speed);
183 }
184
185 if (hu->proto->setup)
186 return hu->proto->setup(hu);
187
188 if (!test_bit(HCI_UART_VND_DETECT, &hu->hdev_flags))
189 return 0;
190
191 skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
192 HCI_INIT_TIMEOUT);
193 if (IS_ERR(skb)) {
194 bt_dev_err(hdev, "Reading local version info failed (%ld)",
195 PTR_ERR(skb));
196 return 0;
197 }
198
199 if (skb->len != sizeof(*ver))
200 bt_dev_err(hdev, "Event length mismatch for version info");
201
202 kfree_skb(skb);
203 return 0;
204}
205
206/** hci_uart_write_wakeup - transmit buffer wakeup
207 * @serdev: serial device
208 *
209 * This function is called by the serdev framework when it accepts
210 * more data being sent.
211 */
212static void hci_uart_write_wakeup(struct serdev_device *serdev)
213{
214 struct hci_uart *hu = serdev_device_get_drvdata(serdev);
215
216 BT_DBG("");
217
218 if (!hu || serdev != hu->serdev) {
219 WARN_ON(1);
220 return;
221 }
222
223 if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
224 hci_uart_tx_wakeup(hu);
225}
226
227/** hci_uart_receive_buf - receive buffer wakeup
228 * @serdev: serial device
229 * @data: pointer to received data
230 * @count: count of received data in bytes
231 *
232 * This function is called by the serdev framework when it received data
233 * in the RX buffer.
234 *
235 * Return: number of processed bytes
236 */
237static int hci_uart_receive_buf(struct serdev_device *serdev, const u8 *data,
238 size_t count)
239{
240 struct hci_uart *hu = serdev_device_get_drvdata(serdev);
241
242 if (!hu || serdev != hu->serdev) {
243 WARN_ON(1);
244 return 0;
245 }
246
247 if (!test_bit(HCI_UART_PROTO_READY, &hu->flags))
248 return 0;
249
250 /* It does not need a lock here as it is already protected by a mutex in
251 * tty caller
252 */
253 hu->proto->recv(hu, data, count);
254
255 if (hu->hdev)
256 hu->hdev->stat.byte_rx += count;
257
258 return count;
259}
260
261static const struct serdev_device_ops hci_serdev_client_ops = {
262 .receive_buf = hci_uart_receive_buf,
263 .write_wakeup = hci_uart_write_wakeup,
264};
265
266int hci_uart_register_device(struct hci_uart *hu,
267 const struct hci_uart_proto *p)
268{
269 int err;
270 struct hci_dev *hdev;
271
272 BT_DBG("");
273
274 serdev_device_set_client_ops(hu->serdev, &hci_serdev_client_ops);
275
276 err = serdev_device_open(hu->serdev);
277 if (err)
278 return err;
279
280 err = p->open(hu);
281 if (err)
282 goto err_open;
283
284 hu->proto = p;
285 set_bit(HCI_UART_PROTO_READY, &hu->flags);
286
287 /* Initialize and register HCI device */
288 hdev = hci_alloc_dev();
289 if (!hdev) {
290 BT_ERR("Can't allocate HCI device");
291 err = -ENOMEM;
292 goto err_alloc;
293 }
294
295 hu->hdev = hdev;
296
297 hdev->bus = HCI_UART;
298 hci_set_drvdata(hdev, hu);
299
300 INIT_WORK(&hu->init_ready, hci_uart_init_work);
301 INIT_WORK(&hu->write_work, hci_uart_write_work);
302 percpu_init_rwsem(&hu->proto_lock);
303
304 /* Only when vendor specific setup callback is provided, consider
305 * the manufacturer information valid. This avoids filling in the
306 * value for Ericsson when nothing is specified.
307 */
308 if (hu->proto->setup)
309 hdev->manufacturer = hu->proto->manufacturer;
310
311 hdev->open = hci_uart_open;
312 hdev->close = hci_uart_close;
313 hdev->flush = hci_uart_flush;
314 hdev->send = hci_uart_send_frame;
315 hdev->setup = hci_uart_setup;
316 SET_HCIDEV_DEV(hdev, &hu->serdev->dev);
317
318 if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
319 set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
320
321 if (test_bit(HCI_UART_EXT_CONFIG, &hu->hdev_flags))
322 set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
323
324 if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
325 hdev->dev_type = HCI_AMP;
326 else
327 hdev->dev_type = HCI_PRIMARY;
328
329 if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
330 return 0;
331
332 if (hci_register_dev(hdev) < 0) {
333 BT_ERR("Can't register HCI device");
334 err = -ENODEV;
335 goto err_register;
336 }
337
338 set_bit(HCI_UART_REGISTERED, &hu->flags);
339
340 return 0;
341
342err_register:
343 hci_free_dev(hdev);
344err_alloc:
345 clear_bit(HCI_UART_PROTO_READY, &hu->flags);
346 p->close(hu);
347err_open:
348 serdev_device_close(hu->serdev);
349 return err;
350}
351EXPORT_SYMBOL_GPL(hci_uart_register_device);
352
353void hci_uart_unregister_device(struct hci_uart *hu)
354{
355 struct hci_dev *hdev = hu->hdev;
356
357 clear_bit(HCI_UART_PROTO_READY, &hu->flags);
358 if (test_bit(HCI_UART_REGISTERED, &hu->flags))
359 hci_unregister_dev(hdev);
360 hci_free_dev(hdev);
361
362 cancel_work_sync(&hu->write_work);
363
364 hu->proto->close(hu);
365 serdev_device_close(hu->serdev);
366}
367EXPORT_SYMBOL_GPL(hci_uart_unregister_device);
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
34static struct serdev_device_ops hci_serdev_client_ops;
35
36static 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
56static 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
68static 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/* Initialize device */
105static int hci_uart_open(struct hci_dev *hdev)
106{
107 BT_DBG("%s %p", hdev->name, hdev);
108
109 return 0;
110}
111
112/* Reset device */
113static int hci_uart_flush(struct hci_dev *hdev)
114{
115 struct hci_uart *hu = hci_get_drvdata(hdev);
116
117 BT_DBG("hdev %p serdev %p", hdev, hu->serdev);
118
119 if (hu->tx_skb) {
120 kfree_skb(hu->tx_skb); hu->tx_skb = NULL;
121 }
122
123 /* Flush any pending characters in the driver and discipline. */
124 serdev_device_write_flush(hu->serdev);
125
126 if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
127 hu->proto->flush(hu);
128
129 return 0;
130}
131
132/* Close device */
133static int hci_uart_close(struct hci_dev *hdev)
134{
135 BT_DBG("hdev %p", hdev);
136
137 hci_uart_flush(hdev);
138 hdev->flush = NULL;
139
140 return 0;
141}
142
143/* Send frames from HCI layer */
144static int hci_uart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
145{
146 struct hci_uart *hu = hci_get_drvdata(hdev);
147
148 BT_DBG("%s: type %d len %d", hdev->name, hci_skb_pkt_type(skb),
149 skb->len);
150
151 hu->proto->enqueue(hu, skb);
152
153 hci_uart_tx_wakeup(hu);
154
155 return 0;
156}
157
158static int hci_uart_setup(struct hci_dev *hdev)
159{
160 struct hci_uart *hu = hci_get_drvdata(hdev);
161 struct hci_rp_read_local_version *ver;
162 struct sk_buff *skb;
163 unsigned int speed;
164 int err;
165
166 /* Init speed if any */
167 if (hu->init_speed)
168 speed = hu->init_speed;
169 else if (hu->proto->init_speed)
170 speed = hu->proto->init_speed;
171 else
172 speed = 0;
173
174 if (speed)
175 serdev_device_set_baudrate(hu->serdev, speed);
176
177 /* Operational speed if any */
178 if (hu->oper_speed)
179 speed = hu->oper_speed;
180 else if (hu->proto->oper_speed)
181 speed = hu->proto->oper_speed;
182 else
183 speed = 0;
184
185 if (hu->proto->set_baudrate && speed) {
186 err = hu->proto->set_baudrate(hu, speed);
187 if (err)
188 bt_dev_err(hdev, "Failed to set baudrate");
189 else
190 serdev_device_set_baudrate(hu->serdev, speed);
191 }
192
193 if (hu->proto->setup)
194 return hu->proto->setup(hu);
195
196 if (!test_bit(HCI_UART_VND_DETECT, &hu->hdev_flags))
197 return 0;
198
199 skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
200 HCI_INIT_TIMEOUT);
201 if (IS_ERR(skb)) {
202 bt_dev_err(hdev, "Reading local version info failed (%ld)",
203 PTR_ERR(skb));
204 return 0;
205 }
206
207 if (skb->len != sizeof(*ver)) {
208 bt_dev_err(hdev, "Event length mismatch for version info");
209 }
210
211 kfree_skb(skb);
212 return 0;
213}
214
215/** hci_uart_write_wakeup - transmit buffer wakeup
216 * @serdev: serial device
217 *
218 * This function is called by the serdev framework when it accepts
219 * more data being sent.
220 */
221static void hci_uart_write_wakeup(struct serdev_device *serdev)
222{
223 struct hci_uart *hu = serdev_device_get_drvdata(serdev);
224
225 BT_DBG("");
226
227 if (!hu || serdev != hu->serdev) {
228 WARN_ON(1);
229 return;
230 }
231
232 if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
233 hci_uart_tx_wakeup(hu);
234}
235
236/** hci_uart_receive_buf - receive buffer wakeup
237 * @serdev: serial device
238 * @data: pointer to received data
239 * @count: count of received data in bytes
240 *
241 * This function is called by the serdev framework when it received data
242 * in the RX buffer.
243 *
244 * Return: number of processed bytes
245 */
246static int hci_uart_receive_buf(struct serdev_device *serdev, const u8 *data,
247 size_t count)
248{
249 struct hci_uart *hu = serdev_device_get_drvdata(serdev);
250
251 if (!hu || serdev != hu->serdev) {
252 WARN_ON(1);
253 return 0;
254 }
255
256 if (!test_bit(HCI_UART_PROTO_READY, &hu->flags))
257 return 0;
258
259 /* It does not need a lock here as it is already protected by a mutex in
260 * tty caller
261 */
262 hu->proto->recv(hu, data, count);
263
264 if (hu->hdev)
265 hu->hdev->stat.byte_rx += count;
266
267 return count;
268}
269
270static struct serdev_device_ops hci_serdev_client_ops = {
271 .receive_buf = hci_uart_receive_buf,
272 .write_wakeup = hci_uart_write_wakeup,
273};
274
275int hci_uart_register_device(struct hci_uart *hu,
276 const struct hci_uart_proto *p)
277{
278 int err;
279 struct hci_dev *hdev;
280
281 BT_DBG("");
282
283 serdev_device_set_client_ops(hu->serdev, &hci_serdev_client_ops);
284
285 err = p->open(hu);
286 if (err)
287 return err;
288
289 hu->proto = p;
290 set_bit(HCI_UART_PROTO_READY, &hu->flags);
291
292 /* Initialize and register HCI device */
293 hdev = hci_alloc_dev();
294 if (!hdev) {
295 BT_ERR("Can't allocate HCI device");
296 err = -ENOMEM;
297 goto err_alloc;
298 }
299
300 hu->hdev = hdev;
301
302 hdev->bus = HCI_UART;
303 hci_set_drvdata(hdev, hu);
304
305 INIT_WORK(&hu->write_work, hci_uart_write_work);
306 percpu_init_rwsem(&hu->proto_lock);
307
308 /* Only when vendor specific setup callback is provided, consider
309 * the manufacturer information valid. This avoids filling in the
310 * value for Ericsson when nothing is specified.
311 */
312 if (hu->proto->setup)
313 hdev->manufacturer = hu->proto->manufacturer;
314
315 hdev->open = hci_uart_open;
316 hdev->close = hci_uart_close;
317 hdev->flush = hci_uart_flush;
318 hdev->send = hci_uart_send_frame;
319 hdev->setup = hci_uart_setup;
320 SET_HCIDEV_DEV(hdev, &hu->serdev->dev);
321
322 if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
323 set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
324
325 if (test_bit(HCI_UART_EXT_CONFIG, &hu->hdev_flags))
326 set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
327
328 if (!test_bit(HCI_UART_RESET_ON_INIT, &hu->hdev_flags))
329 set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
330
331 if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
332 hdev->dev_type = HCI_AMP;
333 else
334 hdev->dev_type = HCI_PRIMARY;
335
336 if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
337 return 0;
338
339 if (hci_register_dev(hdev) < 0) {
340 BT_ERR("Can't register HCI device");
341 err = -ENODEV;
342 goto err_register;
343 }
344
345 set_bit(HCI_UART_REGISTERED, &hu->flags);
346
347 return 0;
348
349err_register:
350 hci_free_dev(hdev);
351err_alloc:
352 clear_bit(HCI_UART_PROTO_READY, &hu->flags);
353 p->close(hu);
354 return err;
355}
356EXPORT_SYMBOL_GPL(hci_uart_register_device);
357
358void hci_uart_unregister_device(struct hci_uart *hu)
359{
360 struct hci_dev *hdev = hu->hdev;
361
362 hci_unregister_dev(hdev);
363 hci_free_dev(hdev);
364
365 cancel_work_sync(&hu->write_work);
366
367 hu->proto->close(hu);
368}
369EXPORT_SYMBOL_GPL(hci_uart_unregister_device);