blob: abee2216fdeb263bb6cc1d1052a070825f5926cd [file] [log] [blame]
Johan Hedberg7dec65c2012-07-16 16:12:02 +03001/*
2 *
3 * Bluetooth HCI Three-wire UART driver
4 *
5 * Copyright (C) 2012 Intel Corporation
6 *
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 *
22 */
23
24#include <linux/kernel.h>
25#include <linux/errno.h>
26#include <linux/skbuff.h>
27
28#include <net/bluetooth/bluetooth.h>
29#include <net/bluetooth/hci_core.h>
30
31#include "hci_uart.h"
32
Johan Hedbergc0a1b732012-07-16 16:12:06 +030033#define HCI_3WIRE_ACK_PKT 0
34#define HCI_3WIRE_LINK_PKT 15
35
Johan Hedbergafdc9442012-07-16 16:12:18 +030036/* Sliding window size */
37#define H5_TX_WIN_MAX 4
Johan Hedberg3f27e952012-07-16 16:12:04 +030038
39#define H5_ACK_TIMEOUT msecs_to_jiffies(250)
Johan Hedberg40f10222012-07-16 16:12:09 +030040#define H5_SYNC_TIMEOUT msecs_to_jiffies(100)
Johan Hedberg3f27e952012-07-16 16:12:04 +030041
Johan Hedbergbc1f35b2012-07-16 16:12:05 +030042/*
43 * Maximum Three-wire packet:
44 * 4 byte header + max value for 12-bit length + 2 bytes for CRC
45 */
46#define H5_MAX_LEN (4 + 0xfff + 2)
47
Johan Hedberg01977c02012-07-16 16:12:07 +030048/* Convenience macros for reading Three-wire header values */
49#define H5_HDR_SEQ(hdr) ((hdr)[0] & 0x07)
50#define H5_HDR_ACK(hdr) (((hdr)[0] >> 3) & 0x07)
51#define H5_HDR_CRC(hdr) (((hdr)[0] >> 6) & 0x01)
52#define H5_HDR_RELIABLE(hdr) (((hdr)[0] >> 7) & 0x01)
53#define H5_HDR_PKT_TYPE(hdr) ((hdr)[1] & 0x0f)
54#define H5_HDR_LEN(hdr) ((((hdr)[1] >> 4) & 0xff) + ((hdr)[2] << 4))
55
Johan Hedbergbc1f35b2012-07-16 16:12:05 +030056#define SLIP_DELIMITER 0xc0
57#define SLIP_ESC 0xdb
58#define SLIP_ESC_DELIM 0xdc
59#define SLIP_ESC_ESC 0xdd
60
Johan Hedberge0482102012-07-16 16:12:19 +030061/* H5 state flags */
62enum {
63 H5_RX_ESC, /* SLIP escape mode */
64 H5_TX_ACK_REQ, /* Pending ack to send */
65};
66
Johan Hedberg7d664fb2012-07-16 16:12:03 +030067struct h5 {
Johan Hedbergbc1f35b2012-07-16 16:12:05 +030068 struct sk_buff_head unack; /* Unack'ed packets queue */
69 struct sk_buff_head rel; /* Reliable packets queue */
70 struct sk_buff_head unrel; /* Unreliable packets queue */
Johan Hedberg7d664fb2012-07-16 16:12:03 +030071
Johan Hedberge0482102012-07-16 16:12:19 +030072 unsigned long flags;
73
Johan Hedbergbc1f35b2012-07-16 16:12:05 +030074 struct sk_buff *rx_skb; /* Receive buffer */
75 size_t rx_pending; /* Expecting more bytes */
Johan Hedberg43eb12d2012-07-16 16:12:08 +030076 u8 rx_ack; /* Last ack number received */
Johan Hedberg7d664fb2012-07-16 16:12:03 +030077
Prasanna Karthikfa4cf042015-07-23 11:22:56 +000078 int (*rx_func)(struct hci_uart *hu, u8 c);
Johan Hedberg3f27e952012-07-16 16:12:04 +030079
Johan Hedbergbc1f35b2012-07-16 16:12:05 +030080 struct timer_list timer; /* Retransmission timer */
Johan Hedberg7d664fb2012-07-16 16:12:03 +030081
Johan Hedberg43eb12d2012-07-16 16:12:08 +030082 u8 tx_seq; /* Next seq number to send */
Johan Hedberg40f10222012-07-16 16:12:09 +030083 u8 tx_ack; /* Next ack number to send */
Johan Hedbergafdc9442012-07-16 16:12:18 +030084 u8 tx_win; /* Sliding window size */
Johan Hedberg10122d02012-07-16 16:12:14 +030085
Johan Hedbergf674a052012-07-16 16:12:15 +030086 enum {
87 H5_UNINITIALIZED,
88 H5_INITIALIZED,
89 H5_ACTIVE,
90 } state;
91
Johan Hedberg95c5c222012-07-16 16:12:16 +030092 enum {
93 H5_AWAKE,
94 H5_SLEEPING,
95 H5_WAKING_UP,
96 } sleep;
Johan Hedberg7d664fb2012-07-16 16:12:03 +030097};
98
Johan Hedbergbc1f35b2012-07-16 16:12:05 +030099static void h5_reset_rx(struct h5 *h5);
100
Johan Hedberg40f10222012-07-16 16:12:09 +0300101static void h5_link_control(struct hci_uart *hu, const void *data, size_t len)
102{
103 struct h5 *h5 = hu->priv;
104 struct sk_buff *nskb;
105
106 nskb = alloc_skb(3, GFP_ATOMIC);
107 if (!nskb)
108 return;
109
110 bt_cb(nskb)->pkt_type = HCI_3WIRE_LINK_PKT;
111
112 memcpy(skb_put(nskb, len), data, len);
113
114 skb_queue_tail(&h5->unrel, nskb);
115}
116
Johan Hedbergafdc9442012-07-16 16:12:18 +0300117static u8 h5_cfg_field(struct h5 *h5)
118{
119 u8 field = 0;
120
121 /* Sliding window size (first 3 bits) */
122 field |= (h5->tx_win & 7);
123
124 return field;
125}
126
Johan Hedbergf674a052012-07-16 16:12:15 +0300127static void h5_timed_event(unsigned long arg)
128{
129 const unsigned char sync_req[] = { 0x01, 0x7e };
Johan Hedbergafdc9442012-07-16 16:12:18 +0300130 unsigned char conf_req[] = { 0x03, 0xfc, 0x01 };
Prasanna Karthik4a2fa2b2015-09-30 13:02:05 +0000131 struct hci_uart *hu = (struct hci_uart *)arg;
Johan Hedbergf674a052012-07-16 16:12:15 +0300132 struct h5 *h5 = hu->priv;
133 struct sk_buff *skb;
134 unsigned long flags;
135
Johan Hedberg95c5c222012-07-16 16:12:16 +0300136 BT_DBG("%s", hu->hdev->name);
137
Johan Hedbergf674a052012-07-16 16:12:15 +0300138 if (h5->state == H5_UNINITIALIZED)
139 h5_link_control(hu, sync_req, sizeof(sync_req));
140
Johan Hedbergafdc9442012-07-16 16:12:18 +0300141 if (h5->state == H5_INITIALIZED) {
142 conf_req[2] = h5_cfg_field(h5);
Johan Hedbergf674a052012-07-16 16:12:15 +0300143 h5_link_control(hu, conf_req, sizeof(conf_req));
Johan Hedbergafdc9442012-07-16 16:12:18 +0300144 }
Johan Hedbergf674a052012-07-16 16:12:15 +0300145
146 if (h5->state != H5_ACTIVE) {
147 mod_timer(&h5->timer, jiffies + H5_SYNC_TIMEOUT);
148 goto wakeup;
149 }
150
Johan Hedberg95c5c222012-07-16 16:12:16 +0300151 if (h5->sleep != H5_AWAKE) {
152 h5->sleep = H5_SLEEPING;
153 goto wakeup;
154 }
155
Johan Hedbergf674a052012-07-16 16:12:15 +0300156 BT_DBG("hu %p retransmitting %u pkts", hu, h5->unack.qlen);
157
158 spin_lock_irqsave_nested(&h5->unack.lock, flags, SINGLE_DEPTH_NESTING);
159
160 while ((skb = __skb_dequeue_tail(&h5->unack)) != NULL) {
161 h5->tx_seq = (h5->tx_seq - 1) & 0x07;
162 skb_queue_head(&h5->rel, skb);
163 }
164
165 spin_unlock_irqrestore(&h5->unack.lock, flags);
166
167wakeup:
168 hci_uart_tx_wakeup(hu);
169}
170
Loic Poulainb509c022014-10-08 16:54:28 +0200171static void h5_peer_reset(struct hci_uart *hu)
172{
173 struct h5 *h5 = hu->priv;
Loic Poulainb509c022014-10-08 16:54:28 +0200174
175 BT_ERR("Peer device has reset");
176
177 h5->state = H5_UNINITIALIZED;
178
179 del_timer(&h5->timer);
180
181 skb_queue_purge(&h5->rel);
182 skb_queue_purge(&h5->unrel);
183 skb_queue_purge(&h5->unack);
184
185 h5->tx_seq = 0;
186 h5->tx_ack = 0;
187
Marcel Holtmann882809f2014-11-02 08:15:39 +0100188 /* Send reset request to upper stack */
189 hci_reset_dev(hu->hdev);
Loic Poulainb509c022014-10-08 16:54:28 +0200190}
191
Johan Hedberg7dec65c2012-07-16 16:12:02 +0300192static int h5_open(struct hci_uart *hu)
193{
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300194 struct h5 *h5;
Johan Hedberg40f10222012-07-16 16:12:09 +0300195 const unsigned char sync[] = { 0x01, 0x7e };
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300196
197 BT_DBG("hu %p", hu);
198
199 h5 = kzalloc(sizeof(*h5), GFP_KERNEL);
200 if (!h5)
201 return -ENOMEM;
202
203 hu->priv = h5;
204
205 skb_queue_head_init(&h5->unack);
206 skb_queue_head_init(&h5->rel);
207 skb_queue_head_init(&h5->unrel);
208
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300209 h5_reset_rx(h5);
210
Johan Hedberg3f27e952012-07-16 16:12:04 +0300211 init_timer(&h5->timer);
212 h5->timer.function = h5_timed_event;
Prasanna Karthik4a2fa2b2015-09-30 13:02:05 +0000213 h5->timer.data = (unsigned long)hu;
Johan Hedberg3f27e952012-07-16 16:12:04 +0300214
Johan Hedbergafdc9442012-07-16 16:12:18 +0300215 h5->tx_win = H5_TX_WIN_MAX;
216
Johan Hedbergcd1b4422012-07-16 16:12:12 +0300217 set_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags);
218
Johan Hedberg40f10222012-07-16 16:12:09 +0300219 /* Send initial sync request */
220 h5_link_control(hu, sync, sizeof(sync));
221 mod_timer(&h5->timer, jiffies + H5_SYNC_TIMEOUT);
222
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300223 return 0;
Johan Hedberg7dec65c2012-07-16 16:12:02 +0300224}
225
226static int h5_close(struct hci_uart *hu)
227{
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300228 struct h5 *h5 = hu->priv;
229
Michael Knudsenc327cdd2014-02-18 09:48:08 +0100230 del_timer_sync(&h5->timer);
231
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300232 skb_queue_purge(&h5->unack);
233 skb_queue_purge(&h5->rel);
234 skb_queue_purge(&h5->unrel);
235
236 kfree(h5);
237
238 return 0;
Johan Hedberg7dec65c2012-07-16 16:12:02 +0300239}
240
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300241static void h5_pkt_cull(struct h5 *h5)
242{
243 struct sk_buff *skb, *tmp;
244 unsigned long flags;
245 int i, to_remove;
246 u8 seq;
247
248 spin_lock_irqsave(&h5->unack.lock, flags);
249
250 to_remove = skb_queue_len(&h5->unack);
Johan Hedberg40f10222012-07-16 16:12:09 +0300251 if (to_remove == 0)
252 goto unlock;
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300253
254 seq = h5->tx_seq;
255
256 while (to_remove > 0) {
257 if (h5->rx_ack == seq)
258 break;
259
260 to_remove--;
Loic Poulain4807b512014-08-08 19:07:16 +0200261 seq = (seq - 1) & 0x07;
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300262 }
263
264 if (seq != h5->rx_ack)
265 BT_ERR("Controller acked invalid packet");
266
267 i = 0;
268 skb_queue_walk_safe(&h5->unack, skb, tmp) {
269 if (i++ >= to_remove)
270 break;
271
272 __skb_unlink(skb, &h5->unack);
273 kfree_skb(skb);
274 }
275
276 if (skb_queue_empty(&h5->unack))
277 del_timer(&h5->timer);
278
Johan Hedberg40f10222012-07-16 16:12:09 +0300279unlock:
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300280 spin_unlock_irqrestore(&h5->unack.lock, flags);
281}
282
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300283static void h5_handle_internal_rx(struct hci_uart *hu)
284{
Johan Hedberg40f10222012-07-16 16:12:09 +0300285 struct h5 *h5 = hu->priv;
286 const unsigned char sync_req[] = { 0x01, 0x7e };
287 const unsigned char sync_rsp[] = { 0x02, 0x7d };
Johan Hedbergafdc9442012-07-16 16:12:18 +0300288 unsigned char conf_req[] = { 0x03, 0xfc, 0x01 };
289 const unsigned char conf_rsp[] = { 0x04, 0x7b };
Johan Hedberg10122d02012-07-16 16:12:14 +0300290 const unsigned char wakeup_req[] = { 0x05, 0xfa };
291 const unsigned char woken_req[] = { 0x06, 0xf9 };
292 const unsigned char sleep_req[] = { 0x07, 0x78 };
Johan Hedberg40f10222012-07-16 16:12:09 +0300293 const unsigned char *hdr = h5->rx_skb->data;
294 const unsigned char *data = &h5->rx_skb->data[4];
295
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300296 BT_DBG("%s", hu->hdev->name);
Johan Hedberg40f10222012-07-16 16:12:09 +0300297
298 if (H5_HDR_PKT_TYPE(hdr) != HCI_3WIRE_LINK_PKT)
299 return;
300
301 if (H5_HDR_LEN(hdr) < 2)
302 return;
303
Johan Hedbergafdc9442012-07-16 16:12:18 +0300304 conf_req[2] = h5_cfg_field(h5);
305
Johan Hedberg40f10222012-07-16 16:12:09 +0300306 if (memcmp(data, sync_req, 2) == 0) {
Loic Poulainb509c022014-10-08 16:54:28 +0200307 if (h5->state == H5_ACTIVE)
308 h5_peer_reset(hu);
Johan Hedberg40f10222012-07-16 16:12:09 +0300309 h5_link_control(hu, sync_rsp, 2);
310 } else if (memcmp(data, sync_rsp, 2) == 0) {
Loic Poulainb509c022014-10-08 16:54:28 +0200311 if (h5->state == H5_ACTIVE)
312 h5_peer_reset(hu);
Johan Hedbergf674a052012-07-16 16:12:15 +0300313 h5->state = H5_INITIALIZED;
Johan Hedberg40f10222012-07-16 16:12:09 +0300314 h5_link_control(hu, conf_req, 3);
315 } else if (memcmp(data, conf_req, 2) == 0) {
316 h5_link_control(hu, conf_rsp, 2);
317 h5_link_control(hu, conf_req, 3);
318 } else if (memcmp(data, conf_rsp, 2) == 0) {
Johan Hedbergafdc9442012-07-16 16:12:18 +0300319 if (H5_HDR_LEN(hdr) > 2)
320 h5->tx_win = (data[2] & 7);
321 BT_DBG("Three-wire init complete. tx_win %u", h5->tx_win);
Johan Hedbergf674a052012-07-16 16:12:15 +0300322 h5->state = H5_ACTIVE;
Johan Hedbergcd1b4422012-07-16 16:12:12 +0300323 hci_uart_init_ready(hu);
Johan Hedberg40f10222012-07-16 16:12:09 +0300324 return;
Johan Hedberg10122d02012-07-16 16:12:14 +0300325 } else if (memcmp(data, sleep_req, 2) == 0) {
326 BT_DBG("Peer went to sleep");
Johan Hedberg95c5c222012-07-16 16:12:16 +0300327 h5->sleep = H5_SLEEPING;
328 return;
Johan Hedberg10122d02012-07-16 16:12:14 +0300329 } else if (memcmp(data, woken_req, 2) == 0) {
330 BT_DBG("Peer woke up");
Johan Hedberg95c5c222012-07-16 16:12:16 +0300331 h5->sleep = H5_AWAKE;
332 } else if (memcmp(data, wakeup_req, 2) == 0) {
333 BT_DBG("Peer requested wakeup");
334 h5_link_control(hu, woken_req, 2);
335 h5->sleep = H5_AWAKE;
Johan Hedberg40f10222012-07-16 16:12:09 +0300336 } else {
337 BT_DBG("Link Control: 0x%02hhx 0x%02hhx", data[0], data[1]);
338 return;
339 }
340
341 hci_uart_tx_wakeup(hu);
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300342}
343
344static void h5_complete_rx_pkt(struct hci_uart *hu)
345{
346 struct h5 *h5 = hu->priv;
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300347 const unsigned char *hdr = h5->rx_skb->data;
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300348
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300349 if (H5_HDR_RELIABLE(hdr)) {
Johan Hedberg40f10222012-07-16 16:12:09 +0300350 h5->tx_ack = (h5->tx_ack + 1) % 8;
Johan Hedberge0482102012-07-16 16:12:19 +0300351 set_bit(H5_TX_ACK_REQ, &h5->flags);
Johan Hedberg40f10222012-07-16 16:12:09 +0300352 hci_uart_tx_wakeup(hu);
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300353 }
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300354
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300355 h5->rx_ack = H5_HDR_ACK(hdr);
356
357 h5_pkt_cull(h5);
358
359 switch (H5_HDR_PKT_TYPE(hdr)) {
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300360 case HCI_EVENT_PKT:
361 case HCI_ACLDATA_PKT:
362 case HCI_SCODATA_PKT:
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300363 bt_cb(h5->rx_skb)->pkt_type = H5_HDR_PKT_TYPE(hdr);
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300364
365 /* Remove Three-wire header */
366 skb_pull(h5->rx_skb, 4);
367
Marcel Holtmanne1a26172013-10-10 16:52:43 -0700368 hci_recv_frame(hu->hdev, h5->rx_skb);
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300369 h5->rx_skb = NULL;
370
371 break;
372
373 default:
374 h5_handle_internal_rx(hu);
375 break;
376 }
377
378 h5_reset_rx(h5);
379}
380
381static int h5_rx_crc(struct hci_uart *hu, unsigned char c)
382{
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300383 h5_complete_rx_pkt(hu);
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300384
385 return 0;
386}
387
388static int h5_rx_payload(struct hci_uart *hu, unsigned char c)
389{
390 struct h5 *h5 = hu->priv;
391 const unsigned char *hdr = h5->rx_skb->data;
392
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300393 if (H5_HDR_CRC(hdr)) {
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300394 h5->rx_func = h5_rx_crc;
395 h5->rx_pending = 2;
396 } else {
397 h5_complete_rx_pkt(hu);
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300398 }
399
400 return 0;
401}
402
403static int h5_rx_3wire_hdr(struct hci_uart *hu, unsigned char c)
404{
405 struct h5 *h5 = hu->priv;
406 const unsigned char *hdr = h5->rx_skb->data;
407
Johan Hedberg40f10222012-07-16 16:12:09 +0300408 BT_DBG("%s rx: seq %u ack %u crc %u rel %u type %u len %u",
409 hu->hdev->name, H5_HDR_SEQ(hdr), H5_HDR_ACK(hdr),
410 H5_HDR_CRC(hdr), H5_HDR_RELIABLE(hdr), H5_HDR_PKT_TYPE(hdr),
411 H5_HDR_LEN(hdr));
412
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300413 if (((hdr[0] + hdr[1] + hdr[2] + hdr[3]) & 0xff) != 0xff) {
414 BT_ERR("Invalid header checksum");
415 h5_reset_rx(h5);
416 return 0;
417 }
418
Johan Hedberg40f10222012-07-16 16:12:09 +0300419 if (H5_HDR_RELIABLE(hdr) && H5_HDR_SEQ(hdr) != h5->tx_ack) {
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300420 BT_ERR("Out-of-order packet arrived (%u != %u)",
Johan Hedberg40f10222012-07-16 16:12:09 +0300421 H5_HDR_SEQ(hdr), h5->tx_ack);
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300422 h5_reset_rx(h5);
423 return 0;
424 }
425
Johan Hedbergf674a052012-07-16 16:12:15 +0300426 if (h5->state != H5_ACTIVE &&
427 H5_HDR_PKT_TYPE(hdr) != HCI_3WIRE_LINK_PKT) {
428 BT_ERR("Non-link packet received in non-active state");
429 h5_reset_rx(h5);
Loic Poulain48439d52014-06-23 17:42:44 +0200430 return 0;
Johan Hedbergf674a052012-07-16 16:12:15 +0300431 }
432
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300433 h5->rx_func = h5_rx_payload;
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300434 h5->rx_pending = H5_HDR_LEN(hdr);
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300435
436 return 0;
437}
438
439static int h5_rx_pkt_start(struct hci_uart *hu, unsigned char c)
440{
441 struct h5 *h5 = hu->priv;
442
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300443 if (c == SLIP_DELIMITER)
444 return 1;
445
446 h5->rx_func = h5_rx_3wire_hdr;
447 h5->rx_pending = 4;
448
449 h5->rx_skb = bt_skb_alloc(H5_MAX_LEN, GFP_ATOMIC);
450 if (!h5->rx_skb) {
451 BT_ERR("Can't allocate mem for new packet");
452 h5_reset_rx(h5);
453 return -ENOMEM;
454 }
455
Prasanna Karthik4a2fa2b2015-09-30 13:02:05 +0000456 h5->rx_skb->dev = (void *)hu->hdev;
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300457
458 return 0;
459}
460
461static int h5_rx_delimiter(struct hci_uart *hu, unsigned char c)
462{
463 struct h5 *h5 = hu->priv;
464
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300465 if (c == SLIP_DELIMITER)
466 h5->rx_func = h5_rx_pkt_start;
467
468 return 1;
469}
470
471static void h5_unslip_one_byte(struct h5 *h5, unsigned char c)
472{
473 const u8 delim = SLIP_DELIMITER, esc = SLIP_ESC;
474 const u8 *byte = &c;
475
Johan Hedberge0482102012-07-16 16:12:19 +0300476 if (!test_bit(H5_RX_ESC, &h5->flags) && c == SLIP_ESC) {
477 set_bit(H5_RX_ESC, &h5->flags);
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300478 return;
479 }
480
Johan Hedberge0482102012-07-16 16:12:19 +0300481 if (test_and_clear_bit(H5_RX_ESC, &h5->flags)) {
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300482 switch (c) {
483 case SLIP_ESC_DELIM:
484 byte = &delim;
485 break;
486 case SLIP_ESC_ESC:
487 byte = &esc;
488 break;
489 default:
490 BT_ERR("Invalid esc byte 0x%02hhx", c);
491 h5_reset_rx(h5);
492 return;
493 }
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300494 }
495
496 memcpy(skb_put(h5->rx_skb, 1), byte, 1);
497 h5->rx_pending--;
498
Johan Hedberg255a68e2012-07-16 16:12:13 +0300499 BT_DBG("unsliped 0x%02hhx, rx_pending %zu", *byte, h5->rx_pending);
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300500}
501
502static void h5_reset_rx(struct h5 *h5)
503{
504 if (h5->rx_skb) {
505 kfree_skb(h5->rx_skb);
506 h5->rx_skb = NULL;
507 }
508
509 h5->rx_func = h5_rx_delimiter;
510 h5->rx_pending = 0;
Johan Hedberge0482102012-07-16 16:12:19 +0300511 clear_bit(H5_RX_ESC, &h5->flags);
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300512}
513
Marcel Holtmann9d1c40e2015-04-04 20:59:41 -0700514static int h5_recv(struct hci_uart *hu, const void *data, int count)
Johan Hedberg7dec65c2012-07-16 16:12:02 +0300515{
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300516 struct h5 *h5 = hu->priv;
Marcel Holtmann9d1c40e2015-04-04 20:59:41 -0700517 const unsigned char *ptr = data;
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300518
Johan Hedberg255a68e2012-07-16 16:12:13 +0300519 BT_DBG("%s pending %zu count %d", hu->hdev->name, h5->rx_pending,
520 count);
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300521
522 while (count > 0) {
523 int processed;
524
525 if (h5->rx_pending > 0) {
526 if (*ptr == SLIP_DELIMITER) {
527 BT_ERR("Too short H5 packet");
528 h5_reset_rx(h5);
529 continue;
530 }
531
532 h5_unslip_one_byte(h5, *ptr);
533
534 ptr++; count--;
535 continue;
536 }
537
538 processed = h5->rx_func(hu, *ptr);
539 if (processed < 0)
540 return processed;
541
542 ptr += processed;
543 count -= processed;
544 }
545
546 return 0;
Johan Hedberg7dec65c2012-07-16 16:12:02 +0300547}
548
549static int h5_enqueue(struct hci_uart *hu, struct sk_buff *skb)
550{
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300551 struct h5 *h5 = hu->priv;
552
553 if (skb->len > 0xfff) {
554 BT_ERR("Packet too long (%u bytes)", skb->len);
555 kfree_skb(skb);
556 return 0;
557 }
558
Johan Hedbergf674a052012-07-16 16:12:15 +0300559 if (h5->state != H5_ACTIVE) {
560 BT_ERR("Ignoring HCI data in non-active state");
561 kfree_skb(skb);
562 return 0;
563 }
564
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300565 switch (bt_cb(skb)->pkt_type) {
566 case HCI_ACLDATA_PKT:
567 case HCI_COMMAND_PKT:
568 skb_queue_tail(&h5->rel, skb);
569 break;
570
571 case HCI_SCODATA_PKT:
572 skb_queue_tail(&h5->unrel, skb);
573 break;
574
575 default:
576 BT_ERR("Unknown packet type %u", bt_cb(skb)->pkt_type);
577 kfree_skb(skb);
578 break;
579 }
580
581 return 0;
582}
583
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300584static void h5_slip_delim(struct sk_buff *skb)
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300585{
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300586 const char delim = SLIP_DELIMITER;
587
588 memcpy(skb_put(skb, 1), &delim, 1);
589}
590
591static void h5_slip_one_byte(struct sk_buff *skb, u8 c)
592{
593 const char esc_delim[2] = { SLIP_ESC, SLIP_ESC_DELIM };
594 const char esc_esc[2] = { SLIP_ESC, SLIP_ESC_ESC };
595
596 switch (c) {
597 case SLIP_DELIMITER:
598 memcpy(skb_put(skb, 2), &esc_delim, 2);
599 break;
600 case SLIP_ESC:
601 memcpy(skb_put(skb, 2), &esc_esc, 2);
602 break;
603 default:
604 memcpy(skb_put(skb, 1), &c, 1);
605 }
606}
607
Johan Hedbergc826ed02012-07-16 16:12:17 +0300608static bool valid_packet_type(u8 type)
609{
610 switch (type) {
611 case HCI_ACLDATA_PKT:
612 case HCI_COMMAND_PKT:
613 case HCI_SCODATA_PKT:
614 case HCI_3WIRE_LINK_PKT:
615 case HCI_3WIRE_ACK_PKT:
616 return true;
617 default:
618 return false;
619 }
620}
621
622static struct sk_buff *h5_prepare_pkt(struct hci_uart *hu, u8 pkt_type,
623 const u8 *data, size_t len)
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300624{
Johan Hedberg40f10222012-07-16 16:12:09 +0300625 struct h5 *h5 = hu->priv;
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300626 struct sk_buff *nskb;
627 u8 hdr[4];
628 int i;
629
Johan Hedbergc826ed02012-07-16 16:12:17 +0300630 if (!valid_packet_type(pkt_type)) {
631 BT_ERR("Unknown packet type %u", pkt_type);
632 return NULL;
633 }
634
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300635 /*
636 * Max len of packet: (original len + 4 (H5 hdr) + 2 (crc)) * 2
637 * (because bytes 0xc0 and 0xdb are escaped, worst case is when
638 * the packet is all made of 0xc0 and 0xdb) + 2 (0xc0
639 * delimiters at start and end).
640 */
641 nskb = alloc_skb((len + 6) * 2 + 2, GFP_ATOMIC);
642 if (!nskb)
643 return NULL;
644
645 bt_cb(nskb)->pkt_type = pkt_type;
646
647 h5_slip_delim(nskb);
648
Johan Hedberg40f10222012-07-16 16:12:09 +0300649 hdr[0] = h5->tx_ack << 3;
Johan Hedberge0482102012-07-16 16:12:19 +0300650 clear_bit(H5_TX_ACK_REQ, &h5->flags);
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300651
Johan Hedbergc826ed02012-07-16 16:12:17 +0300652 /* Reliable packet? */
653 if (pkt_type == HCI_ACLDATA_PKT || pkt_type == HCI_COMMAND_PKT) {
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300654 hdr[0] |= 1 << 7;
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300655 hdr[0] |= h5->tx_seq;
656 h5->tx_seq = (h5->tx_seq + 1) % 8;
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300657 }
658
659 hdr[1] = pkt_type | ((len & 0x0f) << 4);
660 hdr[2] = len >> 4;
661 hdr[3] = ~((hdr[0] + hdr[1] + hdr[2]) & 0xff);
662
Johan Hedberg40f10222012-07-16 16:12:09 +0300663 BT_DBG("%s tx: seq %u ack %u crc %u rel %u type %u len %u",
664 hu->hdev->name, H5_HDR_SEQ(hdr), H5_HDR_ACK(hdr),
665 H5_HDR_CRC(hdr), H5_HDR_RELIABLE(hdr), H5_HDR_PKT_TYPE(hdr),
666 H5_HDR_LEN(hdr));
667
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300668 for (i = 0; i < 4; i++)
669 h5_slip_one_byte(nskb, hdr[i]);
670
671 for (i = 0; i < len; i++)
672 h5_slip_one_byte(nskb, data[i]);
673
674 h5_slip_delim(nskb);
675
676 return nskb;
677}
678
Johan Hedberg7dec65c2012-07-16 16:12:02 +0300679static struct sk_buff *h5_dequeue(struct hci_uart *hu)
680{
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300681 struct h5 *h5 = hu->priv;
Johan Hedberg3f27e952012-07-16 16:12:04 +0300682 unsigned long flags;
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300683 struct sk_buff *skb, *nskb;
684
Johan Hedberg95c5c222012-07-16 16:12:16 +0300685 if (h5->sleep != H5_AWAKE) {
686 const unsigned char wakeup_req[] = { 0x05, 0xfa };
687
688 if (h5->sleep == H5_WAKING_UP)
689 return NULL;
690
691 h5->sleep = H5_WAKING_UP;
692 BT_DBG("Sending wakeup request");
693
694 mod_timer(&h5->timer, jiffies + HZ / 100);
695 return h5_prepare_pkt(hu, HCI_3WIRE_LINK_PKT, wakeup_req, 2);
696 }
697
Valentin Iliea08b15e2013-08-12 18:46:00 +0300698 skb = skb_dequeue(&h5->unrel);
Prasanna Karthik4a2fa2b2015-09-30 13:02:05 +0000699 if (skb) {
Johan Hedberg40f10222012-07-16 16:12:09 +0300700 nskb = h5_prepare_pkt(hu, bt_cb(skb)->pkt_type,
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300701 skb->data, skb->len);
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300702 if (nskb) {
703 kfree_skb(skb);
704 return nskb;
705 }
706
707 skb_queue_head(&h5->unrel, skb);
708 BT_ERR("Could not dequeue pkt because alloc_skb failed");
709 }
710
Johan Hedberg3f27e952012-07-16 16:12:04 +0300711 spin_lock_irqsave_nested(&h5->unack.lock, flags, SINGLE_DEPTH_NESTING);
712
Johan Hedbergafdc9442012-07-16 16:12:18 +0300713 if (h5->unack.qlen >= h5->tx_win)
Johan Hedberg3f27e952012-07-16 16:12:04 +0300714 goto unlock;
715
Valentin Iliea08b15e2013-08-12 18:46:00 +0300716 skb = skb_dequeue(&h5->rel);
Prasanna Karthik4a2fa2b2015-09-30 13:02:05 +0000717 if (skb) {
Johan Hedberg40f10222012-07-16 16:12:09 +0300718 nskb = h5_prepare_pkt(hu, bt_cb(skb)->pkt_type,
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300719 skb->data, skb->len);
Johan Hedberg3f27e952012-07-16 16:12:04 +0300720 if (nskb) {
721 __skb_queue_tail(&h5->unack, skb);
722 mod_timer(&h5->timer, jiffies + H5_ACK_TIMEOUT);
723 spin_unlock_irqrestore(&h5->unack.lock, flags);
724 return nskb;
725 }
726
727 skb_queue_head(&h5->rel, skb);
728 BT_ERR("Could not dequeue pkt because alloc_skb failed");
729 }
730
731unlock:
732 spin_unlock_irqrestore(&h5->unack.lock, flags);
733
Johan Hedberge0482102012-07-16 16:12:19 +0300734 if (test_bit(H5_TX_ACK_REQ, &h5->flags))
Johan Hedberg40f10222012-07-16 16:12:09 +0300735 return h5_prepare_pkt(hu, HCI_3WIRE_ACK_PKT, NULL, 0);
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300736
Johan Hedberg7dec65c2012-07-16 16:12:02 +0300737 return NULL;
738}
739
740static int h5_flush(struct hci_uart *hu)
741{
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300742 BT_DBG("hu %p", hu);
743 return 0;
Johan Hedberg7dec65c2012-07-16 16:12:02 +0300744}
745
Marcel Holtmann4ee7ef12015-04-04 22:11:43 -0700746static const struct hci_uart_proto h5p = {
Johan Hedberg7dec65c2012-07-16 16:12:02 +0300747 .id = HCI_UART_3WIRE,
Marcel Holtmann7c40fb82015-04-04 22:27:34 -0700748 .name = "Three-wire (H5)",
Johan Hedberg7dec65c2012-07-16 16:12:02 +0300749 .open = h5_open,
750 .close = h5_close,
751 .recv = h5_recv,
752 .enqueue = h5_enqueue,
753 .dequeue = h5_dequeue,
754 .flush = h5_flush,
755};
756
757int __init h5_init(void)
758{
Marcel Holtmann01009ee2015-04-04 22:27:35 -0700759 return hci_uart_register_proto(&h5p);
Johan Hedberg7dec65c2012-07-16 16:12:02 +0300760}
761
762int __exit h5_deinit(void)
763{
764 return hci_uart_unregister_proto(&h5p);
765}