blob: 0879d64b1caf58afb6e5d494c07d9ab7e7cdf983 [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)
Andrei Emeltchenko4223f362015-11-19 11:29:11 +020054#define H5_HDR_LEN(hdr) ((((hdr)[1] >> 4) & 0x0f) + ((hdr)[2] << 4))
Johan Hedberg01977c02012-07-16 16:12:07 +030055
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
Marcel Holtmann618e8bc2015-11-05 07:33:56 +0100110 hci_skb_pkt_type(nskb) = HCI_3WIRE_LINK_PKT;
Johan Hedberg40f10222012-07-16 16:12:09 +0300111
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{
Johan Hedbergafdc9442012-07-16 16:12:18 +0300119 /* Sliding window size (first 3 bits) */
Andrei Emeltchenko742c5952015-11-26 16:49:34 +0200120 return h5->tx_win & 0x07;
Johan Hedbergafdc9442012-07-16 16:12:18 +0300121}
122
Johan Hedbergf674a052012-07-16 16:12:15 +0300123static void h5_timed_event(unsigned long arg)
124{
125 const unsigned char sync_req[] = { 0x01, 0x7e };
Andrei Emeltchenko87a6b9b2015-12-10 17:03:43 +0200126 unsigned char conf_req[3] = { 0x03, 0xfc };
Prasanna Karthik4a2fa2b2015-09-30 13:02:05 +0000127 struct hci_uart *hu = (struct hci_uart *)arg;
Johan Hedbergf674a052012-07-16 16:12:15 +0300128 struct h5 *h5 = hu->priv;
129 struct sk_buff *skb;
130 unsigned long flags;
131
Johan Hedberg95c5c222012-07-16 16:12:16 +0300132 BT_DBG("%s", hu->hdev->name);
133
Johan Hedbergf674a052012-07-16 16:12:15 +0300134 if (h5->state == H5_UNINITIALIZED)
135 h5_link_control(hu, sync_req, sizeof(sync_req));
136
Johan Hedbergafdc9442012-07-16 16:12:18 +0300137 if (h5->state == H5_INITIALIZED) {
138 conf_req[2] = h5_cfg_field(h5);
Johan Hedbergf674a052012-07-16 16:12:15 +0300139 h5_link_control(hu, conf_req, sizeof(conf_req));
Johan Hedbergafdc9442012-07-16 16:12:18 +0300140 }
Johan Hedbergf674a052012-07-16 16:12:15 +0300141
142 if (h5->state != H5_ACTIVE) {
143 mod_timer(&h5->timer, jiffies + H5_SYNC_TIMEOUT);
144 goto wakeup;
145 }
146
Johan Hedberg95c5c222012-07-16 16:12:16 +0300147 if (h5->sleep != H5_AWAKE) {
148 h5->sleep = H5_SLEEPING;
149 goto wakeup;
150 }
151
Johan Hedbergf674a052012-07-16 16:12:15 +0300152 BT_DBG("hu %p retransmitting %u pkts", hu, h5->unack.qlen);
153
154 spin_lock_irqsave_nested(&h5->unack.lock, flags, SINGLE_DEPTH_NESTING);
155
156 while ((skb = __skb_dequeue_tail(&h5->unack)) != NULL) {
157 h5->tx_seq = (h5->tx_seq - 1) & 0x07;
158 skb_queue_head(&h5->rel, skb);
159 }
160
161 spin_unlock_irqrestore(&h5->unack.lock, flags);
162
163wakeup:
164 hci_uart_tx_wakeup(hu);
165}
166
Loic Poulainb509c022014-10-08 16:54:28 +0200167static void h5_peer_reset(struct hci_uart *hu)
168{
169 struct h5 *h5 = hu->priv;
Loic Poulainb509c022014-10-08 16:54:28 +0200170
171 BT_ERR("Peer device has reset");
172
173 h5->state = H5_UNINITIALIZED;
174
175 del_timer(&h5->timer);
176
177 skb_queue_purge(&h5->rel);
178 skb_queue_purge(&h5->unrel);
179 skb_queue_purge(&h5->unack);
180
181 h5->tx_seq = 0;
182 h5->tx_ack = 0;
183
Marcel Holtmann882809f2014-11-02 08:15:39 +0100184 /* Send reset request to upper stack */
185 hci_reset_dev(hu->hdev);
Loic Poulainb509c022014-10-08 16:54:28 +0200186}
187
Johan Hedberg7dec65c2012-07-16 16:12:02 +0300188static int h5_open(struct hci_uart *hu)
189{
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300190 struct h5 *h5;
Johan Hedberg40f10222012-07-16 16:12:09 +0300191 const unsigned char sync[] = { 0x01, 0x7e };
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300192
193 BT_DBG("hu %p", hu);
194
195 h5 = kzalloc(sizeof(*h5), GFP_KERNEL);
196 if (!h5)
197 return -ENOMEM;
198
199 hu->priv = h5;
200
201 skb_queue_head_init(&h5->unack);
202 skb_queue_head_init(&h5->rel);
203 skb_queue_head_init(&h5->unrel);
204
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300205 h5_reset_rx(h5);
206
Johan Hedberg3f27e952012-07-16 16:12:04 +0300207 init_timer(&h5->timer);
208 h5->timer.function = h5_timed_event;
Prasanna Karthik4a2fa2b2015-09-30 13:02:05 +0000209 h5->timer.data = (unsigned long)hu;
Johan Hedberg3f27e952012-07-16 16:12:04 +0300210
Johan Hedbergafdc9442012-07-16 16:12:18 +0300211 h5->tx_win = H5_TX_WIN_MAX;
212
Johan Hedbergcd1b4422012-07-16 16:12:12 +0300213 set_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags);
214
Johan Hedberg40f10222012-07-16 16:12:09 +0300215 /* Send initial sync request */
216 h5_link_control(hu, sync, sizeof(sync));
217 mod_timer(&h5->timer, jiffies + H5_SYNC_TIMEOUT);
218
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300219 return 0;
Johan Hedberg7dec65c2012-07-16 16:12:02 +0300220}
221
222static int h5_close(struct hci_uart *hu)
223{
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300224 struct h5 *h5 = hu->priv;
225
Michael Knudsenc327cdd2014-02-18 09:48:08 +0100226 del_timer_sync(&h5->timer);
227
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300228 skb_queue_purge(&h5->unack);
229 skb_queue_purge(&h5->rel);
230 skb_queue_purge(&h5->unrel);
231
232 kfree(h5);
233
234 return 0;
Johan Hedberg7dec65c2012-07-16 16:12:02 +0300235}
236
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300237static void h5_pkt_cull(struct h5 *h5)
238{
239 struct sk_buff *skb, *tmp;
240 unsigned long flags;
241 int i, to_remove;
242 u8 seq;
243
244 spin_lock_irqsave(&h5->unack.lock, flags);
245
246 to_remove = skb_queue_len(&h5->unack);
Johan Hedberg40f10222012-07-16 16:12:09 +0300247 if (to_remove == 0)
248 goto unlock;
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300249
250 seq = h5->tx_seq;
251
252 while (to_remove > 0) {
253 if (h5->rx_ack == seq)
254 break;
255
256 to_remove--;
Loic Poulain4807b512014-08-08 19:07:16 +0200257 seq = (seq - 1) & 0x07;
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300258 }
259
260 if (seq != h5->rx_ack)
261 BT_ERR("Controller acked invalid packet");
262
263 i = 0;
264 skb_queue_walk_safe(&h5->unack, skb, tmp) {
265 if (i++ >= to_remove)
266 break;
267
268 __skb_unlink(skb, &h5->unack);
269 kfree_skb(skb);
270 }
271
272 if (skb_queue_empty(&h5->unack))
273 del_timer(&h5->timer);
274
Johan Hedberg40f10222012-07-16 16:12:09 +0300275unlock:
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300276 spin_unlock_irqrestore(&h5->unack.lock, flags);
277}
278
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300279static void h5_handle_internal_rx(struct hci_uart *hu)
280{
Johan Hedberg40f10222012-07-16 16:12:09 +0300281 struct h5 *h5 = hu->priv;
282 const unsigned char sync_req[] = { 0x01, 0x7e };
283 const unsigned char sync_rsp[] = { 0x02, 0x7d };
Andrei Emeltchenko87a6b9b2015-12-10 17:03:43 +0200284 unsigned char conf_req[3] = { 0x03, 0xfc };
Johan Hedbergafdc9442012-07-16 16:12:18 +0300285 const unsigned char conf_rsp[] = { 0x04, 0x7b };
Johan Hedberg10122d02012-07-16 16:12:14 +0300286 const unsigned char wakeup_req[] = { 0x05, 0xfa };
287 const unsigned char woken_req[] = { 0x06, 0xf9 };
288 const unsigned char sleep_req[] = { 0x07, 0x78 };
Johan Hedberg40f10222012-07-16 16:12:09 +0300289 const unsigned char *hdr = h5->rx_skb->data;
290 const unsigned char *data = &h5->rx_skb->data[4];
291
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300292 BT_DBG("%s", hu->hdev->name);
Johan Hedberg40f10222012-07-16 16:12:09 +0300293
294 if (H5_HDR_PKT_TYPE(hdr) != HCI_3WIRE_LINK_PKT)
295 return;
296
297 if (H5_HDR_LEN(hdr) < 2)
298 return;
299
Johan Hedbergafdc9442012-07-16 16:12:18 +0300300 conf_req[2] = h5_cfg_field(h5);
301
Johan Hedberg40f10222012-07-16 16:12:09 +0300302 if (memcmp(data, sync_req, 2) == 0) {
Loic Poulainb509c022014-10-08 16:54:28 +0200303 if (h5->state == H5_ACTIVE)
304 h5_peer_reset(hu);
Johan Hedberg40f10222012-07-16 16:12:09 +0300305 h5_link_control(hu, sync_rsp, 2);
306 } else if (memcmp(data, sync_rsp, 2) == 0) {
Loic Poulainb509c022014-10-08 16:54:28 +0200307 if (h5->state == H5_ACTIVE)
308 h5_peer_reset(hu);
Johan Hedbergf674a052012-07-16 16:12:15 +0300309 h5->state = H5_INITIALIZED;
Johan Hedberg40f10222012-07-16 16:12:09 +0300310 h5_link_control(hu, conf_req, 3);
311 } else if (memcmp(data, conf_req, 2) == 0) {
312 h5_link_control(hu, conf_rsp, 2);
313 h5_link_control(hu, conf_req, 3);
314 } else if (memcmp(data, conf_rsp, 2) == 0) {
Johan Hedbergafdc9442012-07-16 16:12:18 +0300315 if (H5_HDR_LEN(hdr) > 2)
Andrei Emeltchenko1d3a1e62015-11-26 16:49:33 +0200316 h5->tx_win = (data[2] & 0x07);
Johan Hedbergafdc9442012-07-16 16:12:18 +0300317 BT_DBG("Three-wire init complete. tx_win %u", h5->tx_win);
Johan Hedbergf674a052012-07-16 16:12:15 +0300318 h5->state = H5_ACTIVE;
Johan Hedbergcd1b4422012-07-16 16:12:12 +0300319 hci_uart_init_ready(hu);
Johan Hedberg40f10222012-07-16 16:12:09 +0300320 return;
Johan Hedberg10122d02012-07-16 16:12:14 +0300321 } else if (memcmp(data, sleep_req, 2) == 0) {
322 BT_DBG("Peer went to sleep");
Johan Hedberg95c5c222012-07-16 16:12:16 +0300323 h5->sleep = H5_SLEEPING;
324 return;
Johan Hedberg10122d02012-07-16 16:12:14 +0300325 } else if (memcmp(data, woken_req, 2) == 0) {
326 BT_DBG("Peer woke up");
Johan Hedberg95c5c222012-07-16 16:12:16 +0300327 h5->sleep = H5_AWAKE;
328 } else if (memcmp(data, wakeup_req, 2) == 0) {
329 BT_DBG("Peer requested wakeup");
330 h5_link_control(hu, woken_req, 2);
331 h5->sleep = H5_AWAKE;
Johan Hedberg40f10222012-07-16 16:12:09 +0300332 } else {
333 BT_DBG("Link Control: 0x%02hhx 0x%02hhx", data[0], data[1]);
334 return;
335 }
336
337 hci_uart_tx_wakeup(hu);
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300338}
339
340static void h5_complete_rx_pkt(struct hci_uart *hu)
341{
342 struct h5 *h5 = hu->priv;
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300343 const unsigned char *hdr = h5->rx_skb->data;
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300344
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300345 if (H5_HDR_RELIABLE(hdr)) {
Johan Hedberg40f10222012-07-16 16:12:09 +0300346 h5->tx_ack = (h5->tx_ack + 1) % 8;
Johan Hedberge0482102012-07-16 16:12:19 +0300347 set_bit(H5_TX_ACK_REQ, &h5->flags);
Johan Hedberg40f10222012-07-16 16:12:09 +0300348 hci_uart_tx_wakeup(hu);
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300349 }
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300350
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300351 h5->rx_ack = H5_HDR_ACK(hdr);
352
353 h5_pkt_cull(h5);
354
355 switch (H5_HDR_PKT_TYPE(hdr)) {
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300356 case HCI_EVENT_PKT:
357 case HCI_ACLDATA_PKT:
358 case HCI_SCODATA_PKT:
Marcel Holtmann618e8bc2015-11-05 07:33:56 +0100359 hci_skb_pkt_type(h5->rx_skb) = H5_HDR_PKT_TYPE(hdr);
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300360
361 /* Remove Three-wire header */
362 skb_pull(h5->rx_skb, 4);
363
Marcel Holtmanne1a26172013-10-10 16:52:43 -0700364 hci_recv_frame(hu->hdev, h5->rx_skb);
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300365 h5->rx_skb = NULL;
366
367 break;
368
369 default:
370 h5_handle_internal_rx(hu);
371 break;
372 }
373
374 h5_reset_rx(h5);
375}
376
377static int h5_rx_crc(struct hci_uart *hu, unsigned char c)
378{
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300379 h5_complete_rx_pkt(hu);
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300380
381 return 0;
382}
383
384static int h5_rx_payload(struct hci_uart *hu, unsigned char c)
385{
386 struct h5 *h5 = hu->priv;
387 const unsigned char *hdr = h5->rx_skb->data;
388
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300389 if (H5_HDR_CRC(hdr)) {
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300390 h5->rx_func = h5_rx_crc;
391 h5->rx_pending = 2;
392 } else {
393 h5_complete_rx_pkt(hu);
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300394 }
395
396 return 0;
397}
398
399static int h5_rx_3wire_hdr(struct hci_uart *hu, unsigned char c)
400{
401 struct h5 *h5 = hu->priv;
402 const unsigned char *hdr = h5->rx_skb->data;
403
Johan Hedberg40f10222012-07-16 16:12:09 +0300404 BT_DBG("%s rx: seq %u ack %u crc %u rel %u type %u len %u",
405 hu->hdev->name, H5_HDR_SEQ(hdr), H5_HDR_ACK(hdr),
406 H5_HDR_CRC(hdr), H5_HDR_RELIABLE(hdr), H5_HDR_PKT_TYPE(hdr),
407 H5_HDR_LEN(hdr));
408
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300409 if (((hdr[0] + hdr[1] + hdr[2] + hdr[3]) & 0xff) != 0xff) {
410 BT_ERR("Invalid header checksum");
411 h5_reset_rx(h5);
412 return 0;
413 }
414
Johan Hedberg40f10222012-07-16 16:12:09 +0300415 if (H5_HDR_RELIABLE(hdr) && H5_HDR_SEQ(hdr) != h5->tx_ack) {
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300416 BT_ERR("Out-of-order packet arrived (%u != %u)",
Johan Hedberg40f10222012-07-16 16:12:09 +0300417 H5_HDR_SEQ(hdr), h5->tx_ack);
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300418 h5_reset_rx(h5);
419 return 0;
420 }
421
Johan Hedbergf674a052012-07-16 16:12:15 +0300422 if (h5->state != H5_ACTIVE &&
423 H5_HDR_PKT_TYPE(hdr) != HCI_3WIRE_LINK_PKT) {
424 BT_ERR("Non-link packet received in non-active state");
425 h5_reset_rx(h5);
Loic Poulain48439d52014-06-23 17:42:44 +0200426 return 0;
Johan Hedbergf674a052012-07-16 16:12:15 +0300427 }
428
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300429 h5->rx_func = h5_rx_payload;
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300430 h5->rx_pending = H5_HDR_LEN(hdr);
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300431
432 return 0;
433}
434
435static int h5_rx_pkt_start(struct hci_uart *hu, unsigned char c)
436{
437 struct h5 *h5 = hu->priv;
438
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300439 if (c == SLIP_DELIMITER)
440 return 1;
441
442 h5->rx_func = h5_rx_3wire_hdr;
443 h5->rx_pending = 4;
444
445 h5->rx_skb = bt_skb_alloc(H5_MAX_LEN, GFP_ATOMIC);
446 if (!h5->rx_skb) {
447 BT_ERR("Can't allocate mem for new packet");
448 h5_reset_rx(h5);
449 return -ENOMEM;
450 }
451
Prasanna Karthik4a2fa2b2015-09-30 13:02:05 +0000452 h5->rx_skb->dev = (void *)hu->hdev;
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300453
454 return 0;
455}
456
457static int h5_rx_delimiter(struct hci_uart *hu, unsigned char c)
458{
459 struct h5 *h5 = hu->priv;
460
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300461 if (c == SLIP_DELIMITER)
462 h5->rx_func = h5_rx_pkt_start;
463
464 return 1;
465}
466
467static void h5_unslip_one_byte(struct h5 *h5, unsigned char c)
468{
469 const u8 delim = SLIP_DELIMITER, esc = SLIP_ESC;
470 const u8 *byte = &c;
471
Johan Hedberge0482102012-07-16 16:12:19 +0300472 if (!test_bit(H5_RX_ESC, &h5->flags) && c == SLIP_ESC) {
473 set_bit(H5_RX_ESC, &h5->flags);
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300474 return;
475 }
476
Johan Hedberge0482102012-07-16 16:12:19 +0300477 if (test_and_clear_bit(H5_RX_ESC, &h5->flags)) {
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300478 switch (c) {
479 case SLIP_ESC_DELIM:
480 byte = &delim;
481 break;
482 case SLIP_ESC_ESC:
483 byte = &esc;
484 break;
485 default:
486 BT_ERR("Invalid esc byte 0x%02hhx", c);
487 h5_reset_rx(h5);
488 return;
489 }
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300490 }
491
492 memcpy(skb_put(h5->rx_skb, 1), byte, 1);
493 h5->rx_pending--;
494
Johan Hedberg255a68e2012-07-16 16:12:13 +0300495 BT_DBG("unsliped 0x%02hhx, rx_pending %zu", *byte, h5->rx_pending);
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300496}
497
498static void h5_reset_rx(struct h5 *h5)
499{
500 if (h5->rx_skb) {
501 kfree_skb(h5->rx_skb);
502 h5->rx_skb = NULL;
503 }
504
505 h5->rx_func = h5_rx_delimiter;
506 h5->rx_pending = 0;
Johan Hedberge0482102012-07-16 16:12:19 +0300507 clear_bit(H5_RX_ESC, &h5->flags);
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300508}
509
Marcel Holtmann9d1c40e2015-04-04 20:59:41 -0700510static int h5_recv(struct hci_uart *hu, const void *data, int count)
Johan Hedberg7dec65c2012-07-16 16:12:02 +0300511{
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300512 struct h5 *h5 = hu->priv;
Marcel Holtmann9d1c40e2015-04-04 20:59:41 -0700513 const unsigned char *ptr = data;
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300514
Johan Hedberg255a68e2012-07-16 16:12:13 +0300515 BT_DBG("%s pending %zu count %d", hu->hdev->name, h5->rx_pending,
516 count);
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300517
518 while (count > 0) {
519 int processed;
520
521 if (h5->rx_pending > 0) {
522 if (*ptr == SLIP_DELIMITER) {
523 BT_ERR("Too short H5 packet");
524 h5_reset_rx(h5);
525 continue;
526 }
527
528 h5_unslip_one_byte(h5, *ptr);
529
530 ptr++; count--;
531 continue;
532 }
533
534 processed = h5->rx_func(hu, *ptr);
535 if (processed < 0)
536 return processed;
537
538 ptr += processed;
539 count -= processed;
540 }
541
542 return 0;
Johan Hedberg7dec65c2012-07-16 16:12:02 +0300543}
544
545static int h5_enqueue(struct hci_uart *hu, struct sk_buff *skb)
546{
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300547 struct h5 *h5 = hu->priv;
548
549 if (skb->len > 0xfff) {
550 BT_ERR("Packet too long (%u bytes)", skb->len);
551 kfree_skb(skb);
552 return 0;
553 }
554
Johan Hedbergf674a052012-07-16 16:12:15 +0300555 if (h5->state != H5_ACTIVE) {
556 BT_ERR("Ignoring HCI data in non-active state");
557 kfree_skb(skb);
558 return 0;
559 }
560
Marcel Holtmann618e8bc2015-11-05 07:33:56 +0100561 switch (hci_skb_pkt_type(skb)) {
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300562 case HCI_ACLDATA_PKT:
563 case HCI_COMMAND_PKT:
564 skb_queue_tail(&h5->rel, skb);
565 break;
566
567 case HCI_SCODATA_PKT:
568 skb_queue_tail(&h5->unrel, skb);
569 break;
570
571 default:
Marcel Holtmann618e8bc2015-11-05 07:33:56 +0100572 BT_ERR("Unknown packet type %u", hci_skb_pkt_type(skb));
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300573 kfree_skb(skb);
574 break;
575 }
576
577 return 0;
578}
579
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300580static void h5_slip_delim(struct sk_buff *skb)
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300581{
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300582 const char delim = SLIP_DELIMITER;
583
584 memcpy(skb_put(skb, 1), &delim, 1);
585}
586
587static void h5_slip_one_byte(struct sk_buff *skb, u8 c)
588{
589 const char esc_delim[2] = { SLIP_ESC, SLIP_ESC_DELIM };
590 const char esc_esc[2] = { SLIP_ESC, SLIP_ESC_ESC };
591
592 switch (c) {
593 case SLIP_DELIMITER:
594 memcpy(skb_put(skb, 2), &esc_delim, 2);
595 break;
596 case SLIP_ESC:
597 memcpy(skb_put(skb, 2), &esc_esc, 2);
598 break;
599 default:
600 memcpy(skb_put(skb, 1), &c, 1);
601 }
602}
603
Johan Hedbergc826ed02012-07-16 16:12:17 +0300604static bool valid_packet_type(u8 type)
605{
606 switch (type) {
607 case HCI_ACLDATA_PKT:
608 case HCI_COMMAND_PKT:
609 case HCI_SCODATA_PKT:
610 case HCI_3WIRE_LINK_PKT:
611 case HCI_3WIRE_ACK_PKT:
612 return true;
613 default:
614 return false;
615 }
616}
617
618static struct sk_buff *h5_prepare_pkt(struct hci_uart *hu, u8 pkt_type,
619 const u8 *data, size_t len)
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300620{
Johan Hedberg40f10222012-07-16 16:12:09 +0300621 struct h5 *h5 = hu->priv;
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300622 struct sk_buff *nskb;
623 u8 hdr[4];
624 int i;
625
Johan Hedbergc826ed02012-07-16 16:12:17 +0300626 if (!valid_packet_type(pkt_type)) {
627 BT_ERR("Unknown packet type %u", pkt_type);
628 return NULL;
629 }
630
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300631 /*
632 * Max len of packet: (original len + 4 (H5 hdr) + 2 (crc)) * 2
633 * (because bytes 0xc0 and 0xdb are escaped, worst case is when
634 * the packet is all made of 0xc0 and 0xdb) + 2 (0xc0
635 * delimiters at start and end).
636 */
637 nskb = alloc_skb((len + 6) * 2 + 2, GFP_ATOMIC);
638 if (!nskb)
639 return NULL;
640
Marcel Holtmann618e8bc2015-11-05 07:33:56 +0100641 hci_skb_pkt_type(nskb) = pkt_type;
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300642
643 h5_slip_delim(nskb);
644
Johan Hedberg40f10222012-07-16 16:12:09 +0300645 hdr[0] = h5->tx_ack << 3;
Johan Hedberge0482102012-07-16 16:12:19 +0300646 clear_bit(H5_TX_ACK_REQ, &h5->flags);
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300647
Johan Hedbergc826ed02012-07-16 16:12:17 +0300648 /* Reliable packet? */
649 if (pkt_type == HCI_ACLDATA_PKT || pkt_type == HCI_COMMAND_PKT) {
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300650 hdr[0] |= 1 << 7;
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300651 hdr[0] |= h5->tx_seq;
652 h5->tx_seq = (h5->tx_seq + 1) % 8;
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300653 }
654
655 hdr[1] = pkt_type | ((len & 0x0f) << 4);
656 hdr[2] = len >> 4;
657 hdr[3] = ~((hdr[0] + hdr[1] + hdr[2]) & 0xff);
658
Johan Hedberg40f10222012-07-16 16:12:09 +0300659 BT_DBG("%s tx: seq %u ack %u crc %u rel %u type %u len %u",
660 hu->hdev->name, H5_HDR_SEQ(hdr), H5_HDR_ACK(hdr),
661 H5_HDR_CRC(hdr), H5_HDR_RELIABLE(hdr), H5_HDR_PKT_TYPE(hdr),
662 H5_HDR_LEN(hdr));
663
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300664 for (i = 0; i < 4; i++)
665 h5_slip_one_byte(nskb, hdr[i]);
666
667 for (i = 0; i < len; i++)
668 h5_slip_one_byte(nskb, data[i]);
669
670 h5_slip_delim(nskb);
671
672 return nskb;
673}
674
Johan Hedberg7dec65c2012-07-16 16:12:02 +0300675static struct sk_buff *h5_dequeue(struct hci_uart *hu)
676{
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300677 struct h5 *h5 = hu->priv;
Johan Hedberg3f27e952012-07-16 16:12:04 +0300678 unsigned long flags;
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300679 struct sk_buff *skb, *nskb;
680
Johan Hedberg95c5c222012-07-16 16:12:16 +0300681 if (h5->sleep != H5_AWAKE) {
682 const unsigned char wakeup_req[] = { 0x05, 0xfa };
683
684 if (h5->sleep == H5_WAKING_UP)
685 return NULL;
686
687 h5->sleep = H5_WAKING_UP;
688 BT_DBG("Sending wakeup request");
689
690 mod_timer(&h5->timer, jiffies + HZ / 100);
691 return h5_prepare_pkt(hu, HCI_3WIRE_LINK_PKT, wakeup_req, 2);
692 }
693
Valentin Iliea08b15e2013-08-12 18:46:00 +0300694 skb = skb_dequeue(&h5->unrel);
Prasanna Karthik4a2fa2b2015-09-30 13:02:05 +0000695 if (skb) {
Marcel Holtmann618e8bc2015-11-05 07:33:56 +0100696 nskb = h5_prepare_pkt(hu, hci_skb_pkt_type(skb),
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300697 skb->data, skb->len);
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300698 if (nskb) {
699 kfree_skb(skb);
700 return nskb;
701 }
702
703 skb_queue_head(&h5->unrel, skb);
704 BT_ERR("Could not dequeue pkt because alloc_skb failed");
705 }
706
Johan Hedberg3f27e952012-07-16 16:12:04 +0300707 spin_lock_irqsave_nested(&h5->unack.lock, flags, SINGLE_DEPTH_NESTING);
708
Johan Hedbergafdc9442012-07-16 16:12:18 +0300709 if (h5->unack.qlen >= h5->tx_win)
Johan Hedberg3f27e952012-07-16 16:12:04 +0300710 goto unlock;
711
Valentin Iliea08b15e2013-08-12 18:46:00 +0300712 skb = skb_dequeue(&h5->rel);
Prasanna Karthik4a2fa2b2015-09-30 13:02:05 +0000713 if (skb) {
Marcel Holtmann618e8bc2015-11-05 07:33:56 +0100714 nskb = h5_prepare_pkt(hu, hci_skb_pkt_type(skb),
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300715 skb->data, skb->len);
Johan Hedberg3f27e952012-07-16 16:12:04 +0300716 if (nskb) {
717 __skb_queue_tail(&h5->unack, skb);
718 mod_timer(&h5->timer, jiffies + H5_ACK_TIMEOUT);
719 spin_unlock_irqrestore(&h5->unack.lock, flags);
720 return nskb;
721 }
722
723 skb_queue_head(&h5->rel, skb);
724 BT_ERR("Could not dequeue pkt because alloc_skb failed");
725 }
726
727unlock:
728 spin_unlock_irqrestore(&h5->unack.lock, flags);
729
Johan Hedberge0482102012-07-16 16:12:19 +0300730 if (test_bit(H5_TX_ACK_REQ, &h5->flags))
Johan Hedberg40f10222012-07-16 16:12:09 +0300731 return h5_prepare_pkt(hu, HCI_3WIRE_ACK_PKT, NULL, 0);
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300732
Johan Hedberg7dec65c2012-07-16 16:12:02 +0300733 return NULL;
734}
735
736static int h5_flush(struct hci_uart *hu)
737{
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300738 BT_DBG("hu %p", hu);
739 return 0;
Johan Hedberg7dec65c2012-07-16 16:12:02 +0300740}
741
Marcel Holtmann4ee7ef12015-04-04 22:11:43 -0700742static const struct hci_uart_proto h5p = {
Johan Hedberg7dec65c2012-07-16 16:12:02 +0300743 .id = HCI_UART_3WIRE,
Marcel Holtmann7c40fb82015-04-04 22:27:34 -0700744 .name = "Three-wire (H5)",
Johan Hedberg7dec65c2012-07-16 16:12:02 +0300745 .open = h5_open,
746 .close = h5_close,
747 .recv = h5_recv,
748 .enqueue = h5_enqueue,
749 .dequeue = h5_dequeue,
750 .flush = h5_flush,
751};
752
753int __init h5_init(void)
754{
Marcel Holtmann01009ee2015-04-04 22:27:35 -0700755 return hci_uart_register_proto(&h5p);
Johan Hedberg7dec65c2012-07-16 16:12:02 +0300756}
757
758int __exit h5_deinit(void)
759{
760 return hci_uart_unregister_proto(&h5p);
761}