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#define DEBUG
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	if (test_and_set_bit(HCI_RUNNING, &hdev->flags))
159		return -EBUSY;
160
161	/* provide contexts for callbacks from ST */
162	hst = hci_get_drvdata(hdev);
163
164	for (i = 0; i < MAX_BT_CHNL_IDS; i++) {
165		ti_st_proto[i].priv_data = hst;
166		ti_st_proto[i].max_frame_size = HCI_MAX_FRAME_SIZE;
167		ti_st_proto[i].recv = st_receive;
168		ti_st_proto[i].reg_complete_cb = st_reg_completion_cb;
169
170		/* Prepare wait-for-completion handler */
171		init_completion(&hst->wait_reg_completion);
172		/* Reset ST registration callback status flag,
173		 * this value will be updated in
174		 * st_reg_completion_cb()
175		 * function whenever it called from ST driver.
176		 */
177		hst->reg_status = -EINPROGRESS;
178
179		err = st_register(&ti_st_proto[i]);
180		if (!err)
181			goto done;
182
183		if (err != -EINPROGRESS) {
184			clear_bit(HCI_RUNNING, &hdev->flags);
185			BT_ERR("st_register failed %d", err);
186			return err;
187		}
188
189		/* ST is busy with either protocol
190		 * registration or firmware download.
191		 */
192		BT_DBG("waiting for registration "
193				"completion signal from ST");
194		timeleft = wait_for_completion_timeout
195			(&hst->wait_reg_completion,
196			 msecs_to_jiffies(BT_REGISTER_TIMEOUT));
197		if (!timeleft) {
198			clear_bit(HCI_RUNNING, &hdev->flags);
199			BT_ERR("Timeout(%d sec),didn't get reg "
200					"completion signal from ST",
201					BT_REGISTER_TIMEOUT / 1000);
202			return -ETIMEDOUT;
203		}
204
205		/* Is ST registration callback
206		 * called with ERROR status? */
207		if (hst->reg_status != 0) {
208			clear_bit(HCI_RUNNING, &hdev->flags);
209			BT_ERR("ST registration completed with invalid "
210					"status %d", hst->reg_status);
211			return -EAGAIN;
212		}
213
214done:
215		hst->st_write = ti_st_proto[i].write;
216		if (!hst->st_write) {
217			BT_ERR("undefined ST write function");
218			clear_bit(HCI_RUNNING, &hdev->flags);
219			for (i = 0; i < MAX_BT_CHNL_IDS; i++) {
220				/* Undo registration with ST */
221				err = st_unregister(&ti_st_proto[i]);
222				if (err)
223					BT_ERR("st_unregister() failed with "
224							"error %d", err);
225				hst->st_write = NULL;
226			}
227			return -EIO;
228		}
229	}
230	return 0;
231}
232
233/* Close device */
234static int ti_st_close(struct hci_dev *hdev)
235{
236	int err, i;
237	struct ti_st *hst = hci_get_drvdata(hdev);
238
239	if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
240		return 0;
241
242	for (i = MAX_BT_CHNL_IDS-1; i >= 0; i--) {
243		err = st_unregister(&ti_st_proto[i]);
244		if (err)
245			BT_ERR("st_unregister(%d) failed with error %d",
246					ti_st_proto[i].chnl_id, err);
247	}
248
249	hst->st_write = NULL;
250
251	return err;
252}
253
254static int ti_st_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
255{
256	struct ti_st *hst;
257	long len;
258
259	if (!test_bit(HCI_RUNNING, &hdev->flags))
260		return -EBUSY;
261
262	hst = hci_get_drvdata(hdev);
263
264	/* Prepend skb with frame type */
265	memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
266
267	BT_DBG("%s: type %d len %d", hdev->name, bt_cb(skb)->pkt_type,
268			skb->len);
269
270	/* Insert skb to shared transport layer's transmit queue.
271	 * Freeing skb memory is taken care in shared transport layer,
272	 * so don't free skb memory here.
273	 */
274	len = hst->st_write(skb);
275	if (len < 0) {
276		kfree_skb(skb);
277		BT_ERR("ST write failed (%ld)", len);
278		/* Try Again, would only fail if UART has gone bad */
279		return -EAGAIN;
280	}
281
282	/* ST accepted our skb. So, Go ahead and do rest */
283	hdev->stat.byte_tx += len;
284	ti_st_tx_complete(hst, bt_cb(skb)->pkt_type);
285
286	return 0;
287}
288
289static int bt_ti_probe(struct platform_device *pdev)
290{
291	static struct ti_st *hst;
292	struct hci_dev *hdev;
293	int err;
294
295	hst = devm_kzalloc(&pdev->dev, sizeof(struct ti_st), GFP_KERNEL);
296	if (!hst)
297		return -ENOMEM;
298
299	/* Expose "hciX" device to user space */
300	hdev = hci_alloc_dev();
301	if (!hdev)
302		return -ENOMEM;
303
304	BT_DBG("hdev %p", hdev);
305
306	hst->hdev = hdev;
307	hdev->bus = HCI_UART;
308	hci_set_drvdata(hdev, hst);
309	hdev->open = ti_st_open;
310	hdev->close = ti_st_close;
311	hdev->flush = NULL;
312	hdev->send = ti_st_send_frame;
313
314	err = hci_register_dev(hdev);
315	if (err < 0) {
316		BT_ERR("Can't register HCI device error %d", err);
317		hci_free_dev(hdev);
318		return err;
319	}
320
321	BT_DBG("HCI device registered (hdev %p)", hdev);
322
323	dev_set_drvdata(&pdev->dev, hst);
324	return err;
325}
326
327static int bt_ti_remove(struct platform_device *pdev)
328{
329	struct hci_dev *hdev;
330	struct ti_st *hst = dev_get_drvdata(&pdev->dev);
331
332	if (!hst)
333		return -EFAULT;
334
335	BT_DBG("%s", hst->hdev->name);
336
337	hdev = hst->hdev;
338	ti_st_close(hdev);
339	hci_unregister_dev(hdev);
340
341	hci_free_dev(hdev);
342
343	dev_set_drvdata(&pdev->dev, NULL);
344	return 0;
345}
346
347static struct platform_driver btwilink_driver = {
348	.probe = bt_ti_probe,
349	.remove = bt_ti_remove,
350	.driver = {
351		.name = "btwilink",
352	},
353};
354
355module_platform_driver(btwilink_driver);
356
357/* ------ Module Info ------ */
358
359MODULE_AUTHOR("Raja Mani <raja_mani@ti.com>");
360MODULE_DESCRIPTION("Bluetooth Driver for TI Shared Transport" VERSION);
361MODULE_VERSION(VERSION);
362MODULE_LICENSE("GPL");
363