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  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	int 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, int 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 available */
 97static long st_receive(void *priv_data, struct sk_buff *skb)
 98{
 99	struct ti_st *lhst = priv_data;
100	int err;
101
102	if (!skb)
103		return -EFAULT;
104
105	if (!lhst) {
106		kfree_skb(skb);
107		return -EFAULT;
108	}
109
110	/* Forward skb to HCI core layer */
111	err = hci_recv_frame(lhst->hdev, skb);
112	if (err < 0) {
113		BT_ERR("Unable to push skb to HCI core(%d)", err);
114		return err;
115	}
116
117	lhst->hdev->stat.byte_rx += skb->len;
118
119	return 0;
120}
121
122/* ------- Interfaces to HCI layer ------ */
123/* protocol structure registered with shared transport */
124static struct st_proto_s ti_st_proto[MAX_BT_CHNL_IDS] = {
125	{
126		.chnl_id = HCI_EVENT_PKT, /* HCI Events */
127		.hdr_len = sizeof(struct hci_event_hdr),
128		.offset_len_in_hdr = offsetof(struct hci_event_hdr, plen),
129		.len_size = 1, /* sizeof(plen) in struct hci_event_hdr */
130		.reserve = 8,
131	},
132	{
133		.chnl_id = HCI_ACLDATA_PKT, /* ACL */
134		.hdr_len = sizeof(struct hci_acl_hdr),
135		.offset_len_in_hdr = offsetof(struct hci_acl_hdr, dlen),
136		.len_size = 2,	/* sizeof(dlen) in struct hci_acl_hdr */
137		.reserve = 8,
138	},
139	{
140		.chnl_id = HCI_SCODATA_PKT, /* SCO */
141		.hdr_len = sizeof(struct hci_sco_hdr),
142		.offset_len_in_hdr = offsetof(struct hci_sco_hdr, dlen),
143		.len_size = 1, /* sizeof(dlen) in struct hci_sco_hdr */
144		.reserve = 8,
145	},
146};
147
148/* Called from HCI core to initialize the device */
149static int ti_st_open(struct hci_dev *hdev)
150{
151	unsigned long timeleft;
152	struct ti_st *hst;
153	int err, i;
154
155	BT_DBG("%s %p", hdev->name, hdev);
156
157	/* provide contexts for callbacks from ST */
158	hst = hci_get_drvdata(hdev);
159
160	for (i = 0; i < MAX_BT_CHNL_IDS; i++) {
161		ti_st_proto[i].priv_data = hst;
162		ti_st_proto[i].max_frame_size = HCI_MAX_FRAME_SIZE;
163		ti_st_proto[i].recv = st_receive;
164		ti_st_proto[i].reg_complete_cb = st_reg_completion_cb;
165
166		/* Prepare wait-for-completion handler */
167		init_completion(&hst->wait_reg_completion);
168		/* Reset ST registration callback status flag,
169		 * this value will be updated in
170		 * st_reg_completion_cb()
171		 * function whenever it called from ST driver.
172		 */
173		hst->reg_status = -EINPROGRESS;
174
175		err = st_register(&ti_st_proto[i]);
176		if (!err)
177			goto done;
178
179		if (err != -EINPROGRESS) {
180			BT_ERR("st_register failed %d", err);
181			return err;
182		}
183
184		/* ST is busy with either protocol
185		 * registration or firmware download.
186		 */
187		BT_DBG("waiting for registration "
188				"completion signal from ST");
189		timeleft = wait_for_completion_timeout
190			(&hst->wait_reg_completion,
191			 msecs_to_jiffies(BT_REGISTER_TIMEOUT));
192		if (!timeleft) {
193			BT_ERR("Timeout(%d sec),didn't get reg "
194					"completion signal from ST",
195					BT_REGISTER_TIMEOUT / 1000);
196			return -ETIMEDOUT;
197		}
198
199		/* Is ST registration callback
200		 * called with ERROR status?
201		 */
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	int pkt_type;
249
250	hst = hci_get_drvdata(hdev);
251
252	/* Prepend skb with frame type */
253	memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);
254
255	BT_DBG("%s: type %d len %d", hdev->name, hci_skb_pkt_type(skb),
256	       skb->len);
257
258	/* Insert skb to shared transport layer's transmit queue.
259	 * Freeing skb memory is taken care in shared transport layer,
260	 * so don't free skb memory here.
261	 */
262	pkt_type = hci_skb_pkt_type(skb);
263	len = hst->st_write(skb);
264	if (len < 0) {
265		BT_ERR("ST write failed (%ld)", len);
266		/* Try Again, would only fail if UART has gone bad */
267		return -EAGAIN;
268	}
269
270	/* ST accepted our skb. So, Go ahead and do rest */
271	hdev->stat.byte_tx += len;
272	ti_st_tx_complete(hst, pkt_type);
273
274	return 0;
275}
276
277static int bt_ti_probe(struct platform_device *pdev)
278{
279	struct ti_st *hst;
280	struct hci_dev *hdev;
281	int err;
282
283	hst = devm_kzalloc(&pdev->dev, sizeof(struct ti_st), GFP_KERNEL);
284	if (!hst)
285		return -ENOMEM;
286
287	/* Expose "hciX" device to user space */
288	hdev = hci_alloc_dev();
289	if (!hdev)
290		return -ENOMEM;
291
292	BT_DBG("hdev %p", hdev);
293
294	hst->hdev = hdev;
295	hdev->bus = HCI_UART;
296	hci_set_drvdata(hdev, hst);
297	hdev->open = ti_st_open;
298	hdev->close = ti_st_close;
299	hdev->flush = NULL;
300	hdev->send = ti_st_send_frame;
301
302	err = hci_register_dev(hdev);
303	if (err < 0) {
304		BT_ERR("Can't register HCI device error %d", err);
305		hci_free_dev(hdev);
306		return err;
307	}
308
309	BT_DBG("HCI device registered (hdev %p)", hdev);
310
311	dev_set_drvdata(&pdev->dev, hst);
312	return 0;
313}
314
315static int bt_ti_remove(struct platform_device *pdev)
316{
317	struct hci_dev *hdev;
318	struct ti_st *hst = dev_get_drvdata(&pdev->dev);
319
320	if (!hst)
321		return -EFAULT;
322
323	BT_DBG("%s", hst->hdev->name);
324
325	hdev = hst->hdev;
326	ti_st_close(hdev);
327	hci_unregister_dev(hdev);
328
329	hci_free_dev(hdev);
330
331	dev_set_drvdata(&pdev->dev, NULL);
332	return 0;
333}
334
335static struct platform_driver btwilink_driver = {
336	.probe = bt_ti_probe,
337	.remove = bt_ti_remove,
338	.driver = {
339		.name = "btwilink",
340	},
341};
342
343module_platform_driver(btwilink_driver);
344
345/* ------ Module Info ------ */
346
347MODULE_AUTHOR("Raja Mani <raja_mani@ti.com>");
348MODULE_DESCRIPTION("Bluetooth Driver for TI Shared Transport" VERSION);
349MODULE_VERSION(VERSION);
350MODULE_LICENSE("GPL");