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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#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	skb->dev = (void *) lhst->hdev;
112
113	/* Forward skb to HCI core layer */
114	err = hci_recv_frame(skb);
115	if (err < 0) {
116		BT_ERR("Unable to push skb to HCI core(%d)", err);
117		return err;
118	}
119
120	lhst->hdev->stat.byte_rx += skb->len;
121
122	return 0;
123}
124
125/* ------- Interfaces to HCI layer ------ */
126/* protocol structure registered with shared transport */
127static struct st_proto_s ti_st_proto[MAX_BT_CHNL_IDS] = {
128	{
129		.chnl_id = HCI_EVENT_PKT, /* HCI Events */
130		.hdr_len = sizeof(struct hci_event_hdr),
131		.offset_len_in_hdr = offsetof(struct hci_event_hdr, plen),
132		.len_size = 1, /* sizeof(plen) in struct hci_event_hdr */
133		.reserve = 8,
134	},
135	{
136		.chnl_id = HCI_ACLDATA_PKT, /* ACL */
137		.hdr_len = sizeof(struct hci_acl_hdr),
138		.offset_len_in_hdr = offsetof(struct hci_acl_hdr, dlen),
139		.len_size = 2,	/* sizeof(dlen) in struct hci_acl_hdr */
140		.reserve = 8,
141	},
142	{
143		.chnl_id = HCI_SCODATA_PKT, /* SCO */
144		.hdr_len = sizeof(struct hci_sco_hdr),
145		.offset_len_in_hdr = offsetof(struct hci_sco_hdr, dlen),
146		.len_size = 1, /* sizeof(dlen) in struct hci_sco_hdr */
147		.reserve = 8,
148	},
149};
150
151/* Called from HCI core to initialize the device */
152static int ti_st_open(struct hci_dev *hdev)
153{
154	unsigned long timeleft;
155	struct ti_st *hst;
156	int err, i;
157
158	BT_DBG("%s %p", hdev->name, hdev);
159
160	if (test_and_set_bit(HCI_RUNNING, &hdev->flags))
161		return -EBUSY;
162
163	/* provide contexts for callbacks from ST */
164	hst = hci_get_drvdata(hdev);
165
166	for (i = 0; i < MAX_BT_CHNL_IDS; i++) {
167		ti_st_proto[i].priv_data = hst;
168		ti_st_proto[i].max_frame_size = HCI_MAX_FRAME_SIZE;
169		ti_st_proto[i].recv = st_receive;
170		ti_st_proto[i].reg_complete_cb = st_reg_completion_cb;
171
172		/* Prepare wait-for-completion handler */
173		init_completion(&hst->wait_reg_completion);
174		/* Reset ST registration callback status flag,
175		 * this value will be updated in
176		 * st_reg_completion_cb()
177		 * function whenever it called from ST driver.
178		 */
179		hst->reg_status = -EINPROGRESS;
180
181		err = st_register(&ti_st_proto[i]);
182		if (!err)
183			goto done;
184
185		if (err != -EINPROGRESS) {
186			clear_bit(HCI_RUNNING, &hdev->flags);
187			BT_ERR("st_register failed %d", err);
188			return err;
189		}
190
191		/* ST is busy with either protocol
192		 * registration or firmware download.
193		 */
194		BT_DBG("waiting for registration "
195				"completion signal from ST");
196		timeleft = wait_for_completion_timeout
197			(&hst->wait_reg_completion,
198			 msecs_to_jiffies(BT_REGISTER_TIMEOUT));
199		if (!timeleft) {
200			clear_bit(HCI_RUNNING, &hdev->flags);
201			BT_ERR("Timeout(%d sec),didn't get reg "
202					"completion signal from ST",
203					BT_REGISTER_TIMEOUT / 1000);
204			return -ETIMEDOUT;
205		}
206
207		/* Is ST registration callback
208		 * called with ERROR status? */
209		if (hst->reg_status != 0) {
210			clear_bit(HCI_RUNNING, &hdev->flags);
211			BT_ERR("ST registration completed with invalid "
212					"status %d", hst->reg_status);
213			return -EAGAIN;
214		}
215
216done:
217		hst->st_write = ti_st_proto[i].write;
218		if (!hst->st_write) {
219			BT_ERR("undefined ST write function");
220			clear_bit(HCI_RUNNING, &hdev->flags);
221			for (i = 0; i < MAX_BT_CHNL_IDS; i++) {
222				/* Undo registration with ST */
223				err = st_unregister(&ti_st_proto[i]);
224				if (err)
225					BT_ERR("st_unregister() failed with "
226							"error %d", err);
227				hst->st_write = NULL;
228			}
229			return -EIO;
230		}
231	}
232	return 0;
233}
234
235/* Close device */
236static int ti_st_close(struct hci_dev *hdev)
237{
238	int err, i;
239	struct ti_st *hst = hci_get_drvdata(hdev);
240
241	if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
242		return 0;
243
244	for (i = MAX_BT_CHNL_IDS-1; i >= 0; i--) {
245		err = st_unregister(&ti_st_proto[i]);
246		if (err)
247			BT_ERR("st_unregister(%d) failed with error %d",
248					ti_st_proto[i].chnl_id, err);
249	}
250
251	hst->st_write = NULL;
252
253	return err;
254}
255
256static int ti_st_send_frame(struct sk_buff *skb)
257{
258	struct hci_dev *hdev;
259	struct ti_st *hst;
260	long len;
261
262	hdev = (struct hci_dev *)skb->dev;
263
264	if (!test_bit(HCI_RUNNING, &hdev->flags))
265		return -EBUSY;
266
267	hst = hci_get_drvdata(hdev);
268
269	/* Prepend skb with frame type */
270	memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
271
272	BT_DBG("%s: type %d len %d", hdev->name, bt_cb(skb)->pkt_type,
273			skb->len);
274
275	/* Insert skb to shared transport layer's transmit queue.
276	 * Freeing skb memory is taken care in shared transport layer,
277	 * so don't free skb memory here.
278	 */
279	len = hst->st_write(skb);
280	if (len < 0) {
281		kfree_skb(skb);
282		BT_ERR("ST write failed (%ld)", len);
283		/* Try Again, would only fail if UART has gone bad */
284		return -EAGAIN;
285	}
286
287	/* ST accepted our skb. So, Go ahead and do rest */
288	hdev->stat.byte_tx += len;
289	ti_st_tx_complete(hst, bt_cb(skb)->pkt_type);
290
291	return 0;
292}
293
294static int bt_ti_probe(struct platform_device *pdev)
295{
296	static struct ti_st *hst;
297	struct hci_dev *hdev;
298	int err;
299
300	hst = kzalloc(sizeof(struct ti_st), GFP_KERNEL);
301	if (!hst)
302		return -ENOMEM;
303
304	/* Expose "hciX" device to user space */
305	hdev = hci_alloc_dev();
306	if (!hdev) {
307		kfree(hst);
308		return -ENOMEM;
309	}
310
311	BT_DBG("hdev %p", hdev);
312
313	hst->hdev = hdev;
314	hdev->bus = HCI_UART;
315	hci_set_drvdata(hdev, hst);
316	hdev->open = ti_st_open;
317	hdev->close = ti_st_close;
318	hdev->flush = NULL;
319	hdev->send = ti_st_send_frame;
320
321	err = hci_register_dev(hdev);
322	if (err < 0) {
323		BT_ERR("Can't register HCI device error %d", err);
324		kfree(hst);
325		hci_free_dev(hdev);
326		return err;
327	}
328
329	BT_DBG("HCI device registered (hdev %p)", hdev);
330
331	dev_set_drvdata(&pdev->dev, hst);
332	return err;
333}
334
335static int bt_ti_remove(struct platform_device *pdev)
336{
337	struct hci_dev *hdev;
338	struct ti_st *hst = dev_get_drvdata(&pdev->dev);
339
340	if (!hst)
341		return -EFAULT;
342
343	BT_DBG("%s", hst->hdev->name);
344
345	hdev = hst->hdev;
346	ti_st_close(hdev);
347	hci_unregister_dev(hdev);
348
349	hci_free_dev(hdev);
350	kfree(hst);
351
352	dev_set_drvdata(&pdev->dev, NULL);
353	return 0;
354}
355
356static struct platform_driver btwilink_driver = {
357	.probe = bt_ti_probe,
358	.remove = bt_ti_remove,
359	.driver = {
360		.name = "btwilink",
361		.owner = THIS_MODULE,
362	},
363};
364
365/* ------- Module Init/Exit interfaces ------ */
366static int __init btwilink_init(void)
367{
368	BT_INFO("Bluetooth Driver for TI WiLink - Version %s", VERSION);
369
370	return platform_driver_register(&btwilink_driver);
371}
372
373static void __exit btwilink_exit(void)
374{
375	platform_driver_unregister(&btwilink_driver);
376}
377
378module_init(btwilink_init);
379module_exit(btwilink_exit);
380
381/* ------ Module Info ------ */
382
383MODULE_AUTHOR("Raja Mani <raja_mani@ti.com>");
384MODULE_DESCRIPTION("Bluetooth Driver for TI Shared Transport" VERSION);
385MODULE_VERSION(VERSION);
386MODULE_LICENSE("GPL");