1/*
2 *  Texas Instrument's Bluetooth Driver For Shared Transport.
3 *
4 *  Bluetooth Driver acts as interface between HCI core and
5 *  TI Shared Transport Layer.
6 *
7 *  Copyright (C) 2009-2010 Texas Instruments
8 *  Author: Raja Mani <raja_mani@ti.com>
9 *	Pavan Savoy <pavan_savoy@ti.com>
10 *
11 *  This program is free software; you can redistribute it and/or modify
12 *  it under the terms of the GNU General Public License version 2 as
13 *  published by the Free Software Foundation.
14 *
15 *  This program is distributed in the hope that it will be useful,
16 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
17 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18 *  GNU General Public License for more details.
19 *
20 *  You should have received a copy of the GNU General Public License
21 *  along with this program; if not, write to the Free Software
22 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
23 *
24 */
25
26#include <linux/platform_device.h>
27#include <net/bluetooth/bluetooth.h>
28#include <net/bluetooth/hci_core.h>
29#include <net/bluetooth/hci.h>
30
31#include <linux/ti_wilink_st.h>
32#include <linux/module.h>
33
34/* Bluetooth Driver Version */
35#define VERSION               "1.0"
36#define MAX_BT_CHNL_IDS		3
37
38/* Number of seconds to wait for registration completion
39 * when ST returns PENDING status.
40 */
41#define BT_REGISTER_TIMEOUT   6000	/* 6 sec */
42
43/**
44 * struct ti_st - driver operation structure
45 * @hdev: hci device pointer which binds to bt driver
46 * @reg_status: ST registration callback status
47 * @st_write: write function provided by the ST driver
48 *	to be used by the driver during send_frame.
49 * @wait_reg_completion - completion sync between ti_st_open
50 *	and st_reg_completion_cb.
51 */
52struct ti_st {
53	struct hci_dev *hdev;
54	char reg_status;
55	long (*st_write) (struct sk_buff *);
56	struct completion wait_reg_completion;
57};
58
59/* Increments HCI counters based on pocket ID (cmd,acl,sco) */
60static inline void ti_st_tx_complete(struct ti_st *hst, int pkt_type)
61{
62	struct hci_dev *hdev = hst->hdev;
63
64	/* Update HCI stat counters */
65	switch (pkt_type) {
66	case HCI_COMMAND_PKT:
67		hdev->stat.cmd_tx++;
68		break;
69
70	case HCI_ACLDATA_PKT:
71		hdev->stat.acl_tx++;
72		break;
73
74	case HCI_SCODATA_PKT:
75		hdev->stat.sco_tx++;
76		break;
77	}
78}
79
80/* ------- Interfaces to Shared Transport ------ */
81
82/* Called by ST layer to indicate protocol registration completion
83 * status.ti_st_open() function will wait for signal from this
84 * API when st_register() function returns ST_PENDING.
85 */
86static void st_reg_completion_cb(void *priv_data, char data)
87{
88	struct ti_st *lhst = priv_data;
89
90	/* Save registration status for use in ti_st_open() */
91	lhst->reg_status = data;
92	/* complete the wait in ti_st_open() */
93	complete(&lhst->wait_reg_completion);
94}
95
96/* Called by Shared Transport layer when receive data is
97 * available */
98static long st_receive(void *priv_data, struct sk_buff *skb)
99{
100	struct ti_st *lhst = priv_data;
101	int err;
102
103	if (!skb)
104		return -EFAULT;
105
106	if (!lhst) {
107		kfree_skb(skb);
108		return -EFAULT;
109	}
110
111	/* Forward skb to HCI core layer */
112	err = hci_recv_frame(lhst->hdev, skb);
113	if (err < 0) {
114		BT_ERR("Unable to push skb to HCI core(%d)", err);
115		return err;
116	}
117
118	lhst->hdev->stat.byte_rx += skb->len;
119
120	return 0;
121}
122
123/* ------- Interfaces to HCI layer ------ */
124/* protocol structure registered with shared transport */
125static struct st_proto_s ti_st_proto[MAX_BT_CHNL_IDS] = {
126	{
127		.chnl_id = HCI_EVENT_PKT, /* HCI Events */
128		.hdr_len = sizeof(struct hci_event_hdr),
129		.offset_len_in_hdr = offsetof(struct hci_event_hdr, plen),
130		.len_size = 1, /* sizeof(plen) in struct hci_event_hdr */
131		.reserve = 8,
132	},
133	{
134		.chnl_id = HCI_ACLDATA_PKT, /* ACL */
135		.hdr_len = sizeof(struct hci_acl_hdr),
136		.offset_len_in_hdr = offsetof(struct hci_acl_hdr, dlen),
137		.len_size = 2,	/* sizeof(dlen) in struct hci_acl_hdr */
138		.reserve = 8,
139	},
140	{
141		.chnl_id = HCI_SCODATA_PKT, /* SCO */
142		.hdr_len = sizeof(struct hci_sco_hdr),
143		.offset_len_in_hdr = offsetof(struct hci_sco_hdr, dlen),
144		.len_size = 1, /* sizeof(dlen) in struct hci_sco_hdr */
145		.reserve = 8,
146	},
147};
148
149/* Called from HCI core to initialize the device */
150static int ti_st_open(struct hci_dev *hdev)
151{
152	unsigned long timeleft;
153	struct ti_st *hst;
154	int err, i;
155
156	BT_DBG("%s %p", hdev->name, hdev);
157
158	/* provide contexts for callbacks from ST */
159	hst = hci_get_drvdata(hdev);
160
161	for (i = 0; i < MAX_BT_CHNL_IDS; i++) {
162		ti_st_proto[i].priv_data = hst;
163		ti_st_proto[i].max_frame_size = HCI_MAX_FRAME_SIZE;
164		ti_st_proto[i].recv = st_receive;
165		ti_st_proto[i].reg_complete_cb = st_reg_completion_cb;
166
167		/* Prepare wait-for-completion handler */
168		init_completion(&hst->wait_reg_completion);
169		/* Reset ST registration callback status flag,
170		 * this value will be updated in
171		 * st_reg_completion_cb()
172		 * function whenever it called from ST driver.
173		 */
174		hst->reg_status = -EINPROGRESS;
175
176		err = st_register(&ti_st_proto[i]);
177		if (!err)
178			goto done;
179
180		if (err != -EINPROGRESS) {
181			BT_ERR("st_register failed %d", err);
182			return err;
183		}
184
185		/* ST is busy with either protocol
186		 * registration or firmware download.
187		 */
188		BT_DBG("waiting for registration "
189				"completion signal from ST");
190		timeleft = wait_for_completion_timeout
191			(&hst->wait_reg_completion,
192			 msecs_to_jiffies(BT_REGISTER_TIMEOUT));
193		if (!timeleft) {
194			BT_ERR("Timeout(%d sec),didn't get reg "
195					"completion signal from ST",
196					BT_REGISTER_TIMEOUT / 1000);
197			return -ETIMEDOUT;
198		}
199
200		/* Is ST registration callback
201		 * called with ERROR status? */
202		if (hst->reg_status != 0) {
203			BT_ERR("ST registration completed with invalid "
204					"status %d", hst->reg_status);
205			return -EAGAIN;
206		}
207
208done:
209		hst->st_write = ti_st_proto[i].write;
210		if (!hst->st_write) {
211			BT_ERR("undefined ST write function");
212			for (i = 0; i < MAX_BT_CHNL_IDS; i++) {
213				/* Undo registration with ST */
214				err = st_unregister(&ti_st_proto[i]);
215				if (err)
216					BT_ERR("st_unregister() failed with "
217							"error %d", err);
218				hst->st_write = NULL;
219			}
220			return -EIO;
221		}
222	}
223	return 0;
224}
225
226/* Close device */
227static int ti_st_close(struct hci_dev *hdev)
228{
229	int err, i;
230	struct ti_st *hst = hci_get_drvdata(hdev);
231
232	for (i = MAX_BT_CHNL_IDS-1; i >= 0; i--) {
233		err = st_unregister(&ti_st_proto[i]);
234		if (err)
235			BT_ERR("st_unregister(%d) failed with error %d",
236					ti_st_proto[i].chnl_id, err);
237	}
238
239	hst->st_write = NULL;
240
241	return err;
242}
243
244static int ti_st_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
245{
246	struct ti_st *hst;
247	long len;
248
249	hst = hci_get_drvdata(hdev);
250
251	/* Prepend skb with frame type */
252	memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
253
254	BT_DBG("%s: type %d len %d", hdev->name, bt_cb(skb)->pkt_type,
255			skb->len);
256
257	/* Insert skb to shared transport layer's transmit queue.
258	 * Freeing skb memory is taken care in shared transport layer,
259	 * so don't free skb memory here.
260	 */
261	len = hst->st_write(skb);
262	if (len < 0) {
263		kfree_skb(skb);
264		BT_ERR("ST write failed (%ld)", len);
265		/* Try Again, would only fail if UART has gone bad */
266		return -EAGAIN;
267	}
268
269	/* ST accepted our skb. So, Go ahead and do rest */
270	hdev->stat.byte_tx += len;
271	ti_st_tx_complete(hst, bt_cb(skb)->pkt_type);
272
273	return 0;
274}
275
276static int bt_ti_probe(struct platform_device *pdev)
277{
278	static struct ti_st *hst;
279	struct hci_dev *hdev;
280	int err;
281
282	hst = devm_kzalloc(&pdev->dev, sizeof(struct ti_st), GFP_KERNEL);
283	if (!hst)
284		return -ENOMEM;
285
286	/* Expose "hciX" device to user space */
287	hdev = hci_alloc_dev();
288	if (!hdev)
289		return -ENOMEM;
290
291	BT_DBG("hdev %p", hdev);
292
293	hst->hdev = hdev;
294	hdev->bus = HCI_UART;
295	hci_set_drvdata(hdev, hst);
296	hdev->open = ti_st_open;
297	hdev->close = ti_st_close;
298	hdev->flush = NULL;
299	hdev->send = ti_st_send_frame;
300
301	err = hci_register_dev(hdev);
302	if (err < 0) {
303		BT_ERR("Can't register HCI device error %d", err);
304		hci_free_dev(hdev);
305		return err;
306	}
307
308	BT_DBG("HCI device registered (hdev %p)", hdev);
309
310	dev_set_drvdata(&pdev->dev, hst);
311	return err;
312}
313
314static int bt_ti_remove(struct platform_device *pdev)
315{
316	struct hci_dev *hdev;
317	struct ti_st *hst = dev_get_drvdata(&pdev->dev);
318
319	if (!hst)
320		return -EFAULT;
321
322	BT_DBG("%s", hst->hdev->name);
323
324	hdev = hst->hdev;
325	ti_st_close(hdev);
326	hci_unregister_dev(hdev);
327
328	hci_free_dev(hdev);
329
330	dev_set_drvdata(&pdev->dev, NULL);
331	return 0;
332}
333
334static struct platform_driver btwilink_driver = {
335	.probe = bt_ti_probe,
336	.remove = bt_ti_remove,
337	.driver = {
338		.name = "btwilink",
339	},
340};
341
342module_platform_driver(btwilink_driver);
343
344/* ------ Module Info ------ */
345
346MODULE_AUTHOR("Raja Mani <raja_mani@ti.com>");
347MODULE_DESCRIPTION("Bluetooth Driver for TI Shared Transport" VERSION);
348MODULE_VERSION(VERSION);
349MODULE_LICENSE("GPL");
350