blob: 90d0456b67446bcc624fab4b1542c4eaf21531b1 [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
Prasanna Karthika1e0d042016-10-18 17:30:10 +0000207 setup_timer(&h5->timer, h5_timed_event, (unsigned long)hu);
Johan Hedberg3f27e952012-07-16 16:12:04 +0300208
Johan Hedbergafdc9442012-07-16 16:12:18 +0300209 h5->tx_win = H5_TX_WIN_MAX;
210
Johan Hedbergcd1b4422012-07-16 16:12:12 +0300211 set_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags);
212
Johan Hedberg40f10222012-07-16 16:12:09 +0300213 /* Send initial sync request */
214 h5_link_control(hu, sync, sizeof(sync));
215 mod_timer(&h5->timer, jiffies + H5_SYNC_TIMEOUT);
216
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300217 return 0;
Johan Hedberg7dec65c2012-07-16 16:12:02 +0300218}
219
220static int h5_close(struct hci_uart *hu)
221{
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300222 struct h5 *h5 = hu->priv;
223
Michael Knudsenc327cdd2014-02-18 09:48:08 +0100224 del_timer_sync(&h5->timer);
225
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300226 skb_queue_purge(&h5->unack);
227 skb_queue_purge(&h5->rel);
228 skb_queue_purge(&h5->unrel);
229
230 kfree(h5);
231
232 return 0;
Johan Hedberg7dec65c2012-07-16 16:12:02 +0300233}
234
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300235static void h5_pkt_cull(struct h5 *h5)
236{
237 struct sk_buff *skb, *tmp;
238 unsigned long flags;
239 int i, to_remove;
240 u8 seq;
241
242 spin_lock_irqsave(&h5->unack.lock, flags);
243
244 to_remove = skb_queue_len(&h5->unack);
Johan Hedberg40f10222012-07-16 16:12:09 +0300245 if (to_remove == 0)
246 goto unlock;
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300247
248 seq = h5->tx_seq;
249
250 while (to_remove > 0) {
251 if (h5->rx_ack == seq)
252 break;
253
254 to_remove--;
Loic Poulain4807b512014-08-08 19:07:16 +0200255 seq = (seq - 1) & 0x07;
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300256 }
257
258 if (seq != h5->rx_ack)
259 BT_ERR("Controller acked invalid packet");
260
261 i = 0;
262 skb_queue_walk_safe(&h5->unack, skb, tmp) {
263 if (i++ >= to_remove)
264 break;
265
266 __skb_unlink(skb, &h5->unack);
267 kfree_skb(skb);
268 }
269
270 if (skb_queue_empty(&h5->unack))
271 del_timer(&h5->timer);
272
Johan Hedberg40f10222012-07-16 16:12:09 +0300273unlock:
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300274 spin_unlock_irqrestore(&h5->unack.lock, flags);
275}
276
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300277static void h5_handle_internal_rx(struct hci_uart *hu)
278{
Johan Hedberg40f10222012-07-16 16:12:09 +0300279 struct h5 *h5 = hu->priv;
280 const unsigned char sync_req[] = { 0x01, 0x7e };
281 const unsigned char sync_rsp[] = { 0x02, 0x7d };
Andrei Emeltchenko87a6b9b2015-12-10 17:03:43 +0200282 unsigned char conf_req[3] = { 0x03, 0xfc };
Johan Hedbergafdc9442012-07-16 16:12:18 +0300283 const unsigned char conf_rsp[] = { 0x04, 0x7b };
Johan Hedberg10122d02012-07-16 16:12:14 +0300284 const unsigned char wakeup_req[] = { 0x05, 0xfa };
285 const unsigned char woken_req[] = { 0x06, 0xf9 };
286 const unsigned char sleep_req[] = { 0x07, 0x78 };
Johan Hedberg40f10222012-07-16 16:12:09 +0300287 const unsigned char *hdr = h5->rx_skb->data;
288 const unsigned char *data = &h5->rx_skb->data[4];
289
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300290 BT_DBG("%s", hu->hdev->name);
Johan Hedberg40f10222012-07-16 16:12:09 +0300291
292 if (H5_HDR_PKT_TYPE(hdr) != HCI_3WIRE_LINK_PKT)
293 return;
294
295 if (H5_HDR_LEN(hdr) < 2)
296 return;
297
Johan Hedbergafdc9442012-07-16 16:12:18 +0300298 conf_req[2] = h5_cfg_field(h5);
299
Johan Hedberg40f10222012-07-16 16:12:09 +0300300 if (memcmp(data, sync_req, 2) == 0) {
Loic Poulainb509c022014-10-08 16:54:28 +0200301 if (h5->state == H5_ACTIVE)
302 h5_peer_reset(hu);
Johan Hedberg40f10222012-07-16 16:12:09 +0300303 h5_link_control(hu, sync_rsp, 2);
304 } else if (memcmp(data, sync_rsp, 2) == 0) {
Loic Poulainb509c022014-10-08 16:54:28 +0200305 if (h5->state == H5_ACTIVE)
306 h5_peer_reset(hu);
Johan Hedbergf674a052012-07-16 16:12:15 +0300307 h5->state = H5_INITIALIZED;
Johan Hedberg40f10222012-07-16 16:12:09 +0300308 h5_link_control(hu, conf_req, 3);
309 } else if (memcmp(data, conf_req, 2) == 0) {
310 h5_link_control(hu, conf_rsp, 2);
311 h5_link_control(hu, conf_req, 3);
312 } else if (memcmp(data, conf_rsp, 2) == 0) {
Johan Hedbergafdc9442012-07-16 16:12:18 +0300313 if (H5_HDR_LEN(hdr) > 2)
Andrei Emeltchenko1d3a1e62015-11-26 16:49:33 +0200314 h5->tx_win = (data[2] & 0x07);
Johan Hedbergafdc9442012-07-16 16:12:18 +0300315 BT_DBG("Three-wire init complete. tx_win %u", h5->tx_win);
Johan Hedbergf674a052012-07-16 16:12:15 +0300316 h5->state = H5_ACTIVE;
Johan Hedbergcd1b4422012-07-16 16:12:12 +0300317 hci_uart_init_ready(hu);
Johan Hedberg40f10222012-07-16 16:12:09 +0300318 return;
Johan Hedberg10122d02012-07-16 16:12:14 +0300319 } else if (memcmp(data, sleep_req, 2) == 0) {
320 BT_DBG("Peer went to sleep");
Johan Hedberg95c5c222012-07-16 16:12:16 +0300321 h5->sleep = H5_SLEEPING;
322 return;
Johan Hedberg10122d02012-07-16 16:12:14 +0300323 } else if (memcmp(data, woken_req, 2) == 0) {
324 BT_DBG("Peer woke up");
Johan Hedberg95c5c222012-07-16 16:12:16 +0300325 h5->sleep = H5_AWAKE;
326 } else if (memcmp(data, wakeup_req, 2) == 0) {
327 BT_DBG("Peer requested wakeup");
328 h5_link_control(hu, woken_req, 2);
329 h5->sleep = H5_AWAKE;
Johan Hedberg40f10222012-07-16 16:12:09 +0300330 } else {
331 BT_DBG("Link Control: 0x%02hhx 0x%02hhx", data[0], data[1]);
332 return;
333 }
334
335 hci_uart_tx_wakeup(hu);
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300336}
337
338static void h5_complete_rx_pkt(struct hci_uart *hu)
339{
340 struct h5 *h5 = hu->priv;
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300341 const unsigned char *hdr = h5->rx_skb->data;
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300342
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300343 if (H5_HDR_RELIABLE(hdr)) {
Johan Hedberg40f10222012-07-16 16:12:09 +0300344 h5->tx_ack = (h5->tx_ack + 1) % 8;
Johan Hedberge0482102012-07-16 16:12:19 +0300345 set_bit(H5_TX_ACK_REQ, &h5->flags);
Johan Hedberg40f10222012-07-16 16:12:09 +0300346 hci_uart_tx_wakeup(hu);
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300347 }
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300348
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300349 h5->rx_ack = H5_HDR_ACK(hdr);
350
351 h5_pkt_cull(h5);
352
353 switch (H5_HDR_PKT_TYPE(hdr)) {
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300354 case HCI_EVENT_PKT:
355 case HCI_ACLDATA_PKT:
356 case HCI_SCODATA_PKT:
Marcel Holtmann618e8bc2015-11-05 07:33:56 +0100357 hci_skb_pkt_type(h5->rx_skb) = H5_HDR_PKT_TYPE(hdr);
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300358
359 /* Remove Three-wire header */
360 skb_pull(h5->rx_skb, 4);
361
Marcel Holtmanne1a26172013-10-10 16:52:43 -0700362 hci_recv_frame(hu->hdev, h5->rx_skb);
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300363 h5->rx_skb = NULL;
364
365 break;
366
367 default:
368 h5_handle_internal_rx(hu);
369 break;
370 }
371
372 h5_reset_rx(h5);
373}
374
375static int h5_rx_crc(struct hci_uart *hu, unsigned char c)
376{
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300377 h5_complete_rx_pkt(hu);
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300378
379 return 0;
380}
381
382static int h5_rx_payload(struct hci_uart *hu, unsigned char c)
383{
384 struct h5 *h5 = hu->priv;
385 const unsigned char *hdr = h5->rx_skb->data;
386
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300387 if (H5_HDR_CRC(hdr)) {
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300388 h5->rx_func = h5_rx_crc;
389 h5->rx_pending = 2;
390 } else {
391 h5_complete_rx_pkt(hu);
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300392 }
393
394 return 0;
395}
396
397static int h5_rx_3wire_hdr(struct hci_uart *hu, unsigned char c)
398{
399 struct h5 *h5 = hu->priv;
400 const unsigned char *hdr = h5->rx_skb->data;
401
Johan Hedberg40f10222012-07-16 16:12:09 +0300402 BT_DBG("%s rx: seq %u ack %u crc %u rel %u type %u len %u",
403 hu->hdev->name, H5_HDR_SEQ(hdr), H5_HDR_ACK(hdr),
404 H5_HDR_CRC(hdr), H5_HDR_RELIABLE(hdr), H5_HDR_PKT_TYPE(hdr),
405 H5_HDR_LEN(hdr));
406
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300407 if (((hdr[0] + hdr[1] + hdr[2] + hdr[3]) & 0xff) != 0xff) {
408 BT_ERR("Invalid header checksum");
409 h5_reset_rx(h5);
410 return 0;
411 }
412
Johan Hedberg40f10222012-07-16 16:12:09 +0300413 if (H5_HDR_RELIABLE(hdr) && H5_HDR_SEQ(hdr) != h5->tx_ack) {
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300414 BT_ERR("Out-of-order packet arrived (%u != %u)",
Johan Hedberg40f10222012-07-16 16:12:09 +0300415 H5_HDR_SEQ(hdr), h5->tx_ack);
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300416 h5_reset_rx(h5);
417 return 0;
418 }
419
Johan Hedbergf674a052012-07-16 16:12:15 +0300420 if (h5->state != H5_ACTIVE &&
421 H5_HDR_PKT_TYPE(hdr) != HCI_3WIRE_LINK_PKT) {
422 BT_ERR("Non-link packet received in non-active state");
423 h5_reset_rx(h5);
Loic Poulain48439d52014-06-23 17:42:44 +0200424 return 0;
Johan Hedbergf674a052012-07-16 16:12:15 +0300425 }
426
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300427 h5->rx_func = h5_rx_payload;
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300428 h5->rx_pending = H5_HDR_LEN(hdr);
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300429
430 return 0;
431}
432
433static int h5_rx_pkt_start(struct hci_uart *hu, unsigned char c)
434{
435 struct h5 *h5 = hu->priv;
436
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300437 if (c == SLIP_DELIMITER)
438 return 1;
439
440 h5->rx_func = h5_rx_3wire_hdr;
441 h5->rx_pending = 4;
442
443 h5->rx_skb = bt_skb_alloc(H5_MAX_LEN, GFP_ATOMIC);
444 if (!h5->rx_skb) {
445 BT_ERR("Can't allocate mem for new packet");
446 h5_reset_rx(h5);
447 return -ENOMEM;
448 }
449
Prasanna Karthik4a2fa2b2015-09-30 13:02:05 +0000450 h5->rx_skb->dev = (void *)hu->hdev;
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300451
452 return 0;
453}
454
455static int h5_rx_delimiter(struct hci_uart *hu, unsigned char c)
456{
457 struct h5 *h5 = hu->priv;
458
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300459 if (c == SLIP_DELIMITER)
460 h5->rx_func = h5_rx_pkt_start;
461
462 return 1;
463}
464
465static void h5_unslip_one_byte(struct h5 *h5, unsigned char c)
466{
467 const u8 delim = SLIP_DELIMITER, esc = SLIP_ESC;
468 const u8 *byte = &c;
469
Johan Hedberge0482102012-07-16 16:12:19 +0300470 if (!test_bit(H5_RX_ESC, &h5->flags) && c == SLIP_ESC) {
471 set_bit(H5_RX_ESC, &h5->flags);
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300472 return;
473 }
474
Johan Hedberge0482102012-07-16 16:12:19 +0300475 if (test_and_clear_bit(H5_RX_ESC, &h5->flags)) {
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300476 switch (c) {
477 case SLIP_ESC_DELIM:
478 byte = &delim;
479 break;
480 case SLIP_ESC_ESC:
481 byte = &esc;
482 break;
483 default:
484 BT_ERR("Invalid esc byte 0x%02hhx", c);
485 h5_reset_rx(h5);
486 return;
487 }
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300488 }
489
490 memcpy(skb_put(h5->rx_skb, 1), byte, 1);
491 h5->rx_pending--;
492
Johan Hedberg255a68e2012-07-16 16:12:13 +0300493 BT_DBG("unsliped 0x%02hhx, rx_pending %zu", *byte, h5->rx_pending);
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300494}
495
496static void h5_reset_rx(struct h5 *h5)
497{
498 if (h5->rx_skb) {
499 kfree_skb(h5->rx_skb);
500 h5->rx_skb = NULL;
501 }
502
503 h5->rx_func = h5_rx_delimiter;
504 h5->rx_pending = 0;
Johan Hedberge0482102012-07-16 16:12:19 +0300505 clear_bit(H5_RX_ESC, &h5->flags);
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300506}
507
Marcel Holtmann9d1c40e2015-04-04 20:59:41 -0700508static int h5_recv(struct hci_uart *hu, const void *data, int count)
Johan Hedberg7dec65c2012-07-16 16:12:02 +0300509{
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300510 struct h5 *h5 = hu->priv;
Marcel Holtmann9d1c40e2015-04-04 20:59:41 -0700511 const unsigned char *ptr = data;
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300512
Johan Hedberg255a68e2012-07-16 16:12:13 +0300513 BT_DBG("%s pending %zu count %d", hu->hdev->name, h5->rx_pending,
514 count);
Johan Hedbergbc1f35b2012-07-16 16:12:05 +0300515
516 while (count > 0) {
517 int processed;
518
519 if (h5->rx_pending > 0) {
520 if (*ptr == SLIP_DELIMITER) {
521 BT_ERR("Too short H5 packet");
522 h5_reset_rx(h5);
523 continue;
524 }
525
526 h5_unslip_one_byte(h5, *ptr);
527
528 ptr++; count--;
529 continue;
530 }
531
532 processed = h5->rx_func(hu, *ptr);
533 if (processed < 0)
534 return processed;
535
536 ptr += processed;
537 count -= processed;
538 }
539
540 return 0;
Johan Hedberg7dec65c2012-07-16 16:12:02 +0300541}
542
543static int h5_enqueue(struct hci_uart *hu, struct sk_buff *skb)
544{
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300545 struct h5 *h5 = hu->priv;
546
547 if (skb->len > 0xfff) {
548 BT_ERR("Packet too long (%u bytes)", skb->len);
549 kfree_skb(skb);
550 return 0;
551 }
552
Johan Hedbergf674a052012-07-16 16:12:15 +0300553 if (h5->state != H5_ACTIVE) {
554 BT_ERR("Ignoring HCI data in non-active state");
555 kfree_skb(skb);
556 return 0;
557 }
558
Marcel Holtmann618e8bc2015-11-05 07:33:56 +0100559 switch (hci_skb_pkt_type(skb)) {
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300560 case HCI_ACLDATA_PKT:
561 case HCI_COMMAND_PKT:
562 skb_queue_tail(&h5->rel, skb);
563 break;
564
565 case HCI_SCODATA_PKT:
566 skb_queue_tail(&h5->unrel, skb);
567 break;
568
569 default:
Marcel Holtmann618e8bc2015-11-05 07:33:56 +0100570 BT_ERR("Unknown packet type %u", hci_skb_pkt_type(skb));
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300571 kfree_skb(skb);
572 break;
573 }
574
575 return 0;
576}
577
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300578static void h5_slip_delim(struct sk_buff *skb)
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300579{
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300580 const char delim = SLIP_DELIMITER;
581
582 memcpy(skb_put(skb, 1), &delim, 1);
583}
584
585static void h5_slip_one_byte(struct sk_buff *skb, u8 c)
586{
587 const char esc_delim[2] = { SLIP_ESC, SLIP_ESC_DELIM };
588 const char esc_esc[2] = { SLIP_ESC, SLIP_ESC_ESC };
589
590 switch (c) {
591 case SLIP_DELIMITER:
592 memcpy(skb_put(skb, 2), &esc_delim, 2);
593 break;
594 case SLIP_ESC:
595 memcpy(skb_put(skb, 2), &esc_esc, 2);
596 break;
597 default:
598 memcpy(skb_put(skb, 1), &c, 1);
599 }
600}
601
Johan Hedbergc826ed02012-07-16 16:12:17 +0300602static bool valid_packet_type(u8 type)
603{
604 switch (type) {
605 case HCI_ACLDATA_PKT:
606 case HCI_COMMAND_PKT:
607 case HCI_SCODATA_PKT:
608 case HCI_3WIRE_LINK_PKT:
609 case HCI_3WIRE_ACK_PKT:
610 return true;
611 default:
612 return false;
613 }
614}
615
616static struct sk_buff *h5_prepare_pkt(struct hci_uart *hu, u8 pkt_type,
617 const u8 *data, size_t len)
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300618{
Johan Hedberg40f10222012-07-16 16:12:09 +0300619 struct h5 *h5 = hu->priv;
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300620 struct sk_buff *nskb;
621 u8 hdr[4];
622 int i;
623
Johan Hedbergc826ed02012-07-16 16:12:17 +0300624 if (!valid_packet_type(pkt_type)) {
625 BT_ERR("Unknown packet type %u", pkt_type);
626 return NULL;
627 }
628
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300629 /*
630 * Max len of packet: (original len + 4 (H5 hdr) + 2 (crc)) * 2
631 * (because bytes 0xc0 and 0xdb are escaped, worst case is when
632 * the packet is all made of 0xc0 and 0xdb) + 2 (0xc0
633 * delimiters at start and end).
634 */
635 nskb = alloc_skb((len + 6) * 2 + 2, GFP_ATOMIC);
636 if (!nskb)
637 return NULL;
638
Marcel Holtmann618e8bc2015-11-05 07:33:56 +0100639 hci_skb_pkt_type(nskb) = pkt_type;
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300640
641 h5_slip_delim(nskb);
642
Johan Hedberg40f10222012-07-16 16:12:09 +0300643 hdr[0] = h5->tx_ack << 3;
Johan Hedberge0482102012-07-16 16:12:19 +0300644 clear_bit(H5_TX_ACK_REQ, &h5->flags);
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300645
Johan Hedbergc826ed02012-07-16 16:12:17 +0300646 /* Reliable packet? */
647 if (pkt_type == HCI_ACLDATA_PKT || pkt_type == HCI_COMMAND_PKT) {
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300648 hdr[0] |= 1 << 7;
Johan Hedberg43eb12d2012-07-16 16:12:08 +0300649 hdr[0] |= h5->tx_seq;
650 h5->tx_seq = (h5->tx_seq + 1) % 8;
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300651 }
652
653 hdr[1] = pkt_type | ((len & 0x0f) << 4);
654 hdr[2] = len >> 4;
655 hdr[3] = ~((hdr[0] + hdr[1] + hdr[2]) & 0xff);
656
Johan Hedberg40f10222012-07-16 16:12:09 +0300657 BT_DBG("%s tx: seq %u ack %u crc %u rel %u type %u len %u",
658 hu->hdev->name, H5_HDR_SEQ(hdr), H5_HDR_ACK(hdr),
659 H5_HDR_CRC(hdr), H5_HDR_RELIABLE(hdr), H5_HDR_PKT_TYPE(hdr),
660 H5_HDR_LEN(hdr));
661
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300662 for (i = 0; i < 4; i++)
663 h5_slip_one_byte(nskb, hdr[i]);
664
665 for (i = 0; i < len; i++)
666 h5_slip_one_byte(nskb, data[i]);
667
668 h5_slip_delim(nskb);
669
670 return nskb;
671}
672
Johan Hedberg7dec65c2012-07-16 16:12:02 +0300673static struct sk_buff *h5_dequeue(struct hci_uart *hu)
674{
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300675 struct h5 *h5 = hu->priv;
Johan Hedberg3f27e952012-07-16 16:12:04 +0300676 unsigned long flags;
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300677 struct sk_buff *skb, *nskb;
678
Johan Hedberg95c5c222012-07-16 16:12:16 +0300679 if (h5->sleep != H5_AWAKE) {
680 const unsigned char wakeup_req[] = { 0x05, 0xfa };
681
682 if (h5->sleep == H5_WAKING_UP)
683 return NULL;
684
685 h5->sleep = H5_WAKING_UP;
686 BT_DBG("Sending wakeup request");
687
688 mod_timer(&h5->timer, jiffies + HZ / 100);
689 return h5_prepare_pkt(hu, HCI_3WIRE_LINK_PKT, wakeup_req, 2);
690 }
691
Valentin Iliea08b15e2013-08-12 18:46:00 +0300692 skb = skb_dequeue(&h5->unrel);
Prasanna Karthik4a2fa2b2015-09-30 13:02:05 +0000693 if (skb) {
Marcel Holtmann618e8bc2015-11-05 07:33:56 +0100694 nskb = h5_prepare_pkt(hu, hci_skb_pkt_type(skb),
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300695 skb->data, skb->len);
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300696 if (nskb) {
697 kfree_skb(skb);
698 return nskb;
699 }
700
701 skb_queue_head(&h5->unrel, skb);
702 BT_ERR("Could not dequeue pkt because alloc_skb failed");
703 }
704
Johan Hedberg3f27e952012-07-16 16:12:04 +0300705 spin_lock_irqsave_nested(&h5->unack.lock, flags, SINGLE_DEPTH_NESTING);
706
Johan Hedbergafdc9442012-07-16 16:12:18 +0300707 if (h5->unack.qlen >= h5->tx_win)
Johan Hedberg3f27e952012-07-16 16:12:04 +0300708 goto unlock;
709
Valentin Iliea08b15e2013-08-12 18:46:00 +0300710 skb = skb_dequeue(&h5->rel);
Prasanna Karthik4a2fa2b2015-09-30 13:02:05 +0000711 if (skb) {
Marcel Holtmann618e8bc2015-11-05 07:33:56 +0100712 nskb = h5_prepare_pkt(hu, hci_skb_pkt_type(skb),
Johan Hedbergc0a1b732012-07-16 16:12:06 +0300713 skb->data, skb->len);
Johan Hedberg3f27e952012-07-16 16:12:04 +0300714 if (nskb) {
715 __skb_queue_tail(&h5->unack, skb);
716 mod_timer(&h5->timer, jiffies + H5_ACK_TIMEOUT);
717 spin_unlock_irqrestore(&h5->unack.lock, flags);
718 return nskb;
719 }
720
721 skb_queue_head(&h5->rel, skb);
722 BT_ERR("Could not dequeue pkt because alloc_skb failed");
723 }
724
725unlock:
726 spin_unlock_irqrestore(&h5->unack.lock, flags);
727
Johan Hedberge0482102012-07-16 16:12:19 +0300728 if (test_bit(H5_TX_ACK_REQ, &h5->flags))
Johan Hedberg40f10222012-07-16 16:12:09 +0300729 return h5_prepare_pkt(hu, HCI_3WIRE_ACK_PKT, NULL, 0);
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300730
Johan Hedberg7dec65c2012-07-16 16:12:02 +0300731 return NULL;
732}
733
734static int h5_flush(struct hci_uart *hu)
735{
Johan Hedberg7d664fb2012-07-16 16:12:03 +0300736 BT_DBG("hu %p", hu);
737 return 0;
Johan Hedberg7dec65c2012-07-16 16:12:02 +0300738}
739
Marcel Holtmann4ee7ef12015-04-04 22:11:43 -0700740static const struct hci_uart_proto h5p = {
Johan Hedberg7dec65c2012-07-16 16:12:02 +0300741 .id = HCI_UART_3WIRE,
Marcel Holtmann7c40fb82015-04-04 22:27:34 -0700742 .name = "Three-wire (H5)",
Johan Hedberg7dec65c2012-07-16 16:12:02 +0300743 .open = h5_open,
744 .close = h5_close,
745 .recv = h5_recv,
746 .enqueue = h5_enqueue,
747 .dequeue = h5_dequeue,
748 .flush = h5_flush,
749};
750
751int __init h5_init(void)
752{
Marcel Holtmann01009ee2015-04-04 22:27:35 -0700753 return hci_uart_register_proto(&h5p);
Johan Hedberg7dec65c2012-07-16 16:12:02 +0300754}
755
756int __exit h5_deinit(void)
757{
758 return hci_uart_unregister_proto(&h5p);
759}