aboutsummaryrefslogtreecommitdiff
path: root/drivers/bluetooth/btwilink.c
blob: e55f06e4270f4f251923ecb0814aa58f8bfa67e7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
// SPDX-License-Identifier: GPL-2.0-only
/*
 *  Texas Instrument's Bluetooth Driver For Shared Transport.
 *
 *  Bluetooth Driver acts as interface between HCI core and
 *  TI Shared Transport Layer.
 *
 *  Copyright (C) 2009-2010 Texas Instruments
 *  Author: Raja Mani <raja_mani@ti.com>
 *	Pavan Savoy <pavan_savoy@ti.com>
 */

#include <linux/platform_device.h>
#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci_core.h>
#include <net/bluetooth/hci.h>

#include <linux/ti_wilink_st.h>
#include <linux/module.h>

/* Bluetooth Driver Version */
#define VERSION               "1.0"
#define MAX_BT_CHNL_IDS		3

/* Number of seconds to wait for registration completion
 * when ST returns PENDING status.
 */
#define BT_REGISTER_TIMEOUT   6000	/* 6 sec */

/**
 * struct ti_st - driver operation structure
 * @hdev: hci device pointer which binds to bt driver
 * @reg_status: ST registration callback status
 * @st_write: write function provided by the ST driver
 *	to be used by the driver during send_frame.
 * @wait_reg_completion - completion sync between ti_st_open
 *	and st_reg_completion_cb.
 */
struct ti_st {
	struct hci_dev *hdev;
	int reg_status;
	long (*st_write) (struct sk_buff *);
	struct completion wait_reg_completion;
};

/* Increments HCI counters based on pocket ID (cmd,acl,sco) */
static inline void ti_st_tx_complete(struct ti_st *hst, int pkt_type)
{
	struct hci_dev *hdev = hst->hdev;

	/* Update HCI stat counters */
	switch (pkt_type) {
	case HCI_COMMAND_PKT:
		hdev->stat.cmd_tx++;
		break;

	case HCI_ACLDATA_PKT:
		hdev->stat.acl_tx++;
		break;

	case HCI_SCODATA_PKT:
		hdev->stat.sco_tx++;
		break;
	}
}

/* ------- Interfaces to Shared Transport ------ */

/* Called by ST layer to indicate protocol registration completion
 * status.ti_st_open() function will wait for signal from this
 * API when st_register() function returns ST_PENDING.
 */
static void st_reg_completion_cb(void *priv_data, int data)
{
	struct ti_st *lhst = priv_data;

	/* Save registration status for use in ti_st_open() */
	lhst->reg_status = data;
	/* complete the wait in ti_st_open() */
	complete(&lhst->wait_reg_completion);
}

/* Called by Shared Transport layer when receive data is available */
static long st_receive(void *priv_data, struct sk_buff *skb)
{
	struct ti_st *lhst = priv_data;
	int err;

	if (!skb)
		return -EFAULT;

	if (!lhst) {
		kfree_skb(skb);
		return -EFAULT;
	}

	/* Forward skb to HCI core layer */
	err = hci_recv_frame(lhst->hdev, skb);
	if (err < 0) {
		BT_ERR("Unable to push skb to HCI core(%d)", err);
		return err;
	}

	lhst->hdev->stat.byte_rx += skb->len;

	return 0;
}

/* ------- Interfaces to HCI layer ------ */
/* protocol structure registered with shared transport */
static struct st_proto_s ti_st_proto[MAX_BT_CHNL_IDS] = {
	{
		.chnl_id = HCI_EVENT_PKT, /* HCI Events */
		.hdr_len = sizeof(struct hci_event_hdr),
		.offset_len_in_hdr = offsetof(struct hci_event_hdr, plen),
		.len_size = 1, /* sizeof(plen) in struct hci_event_hdr */
		.reserve = 8,
	},
	{
		.chnl_id = HCI_ACLDATA_PKT, /* ACL */
		.hdr_len = sizeof(struct hci_acl_hdr),
		.offset_len_in_hdr = offsetof(struct hci_acl_hdr, dlen),
		.len_size = 2,	/* sizeof(dlen) in struct hci_acl_hdr */
		.reserve = 8,
	},
	{
		.chnl_id = HCI_SCODATA_PKT, /* SCO */
		.hdr_len = sizeof(struct hci_sco_hdr),
		.offset_len_in_hdr = offsetof(struct hci_sco_hdr, dlen),
		.len_size = 1, /* sizeof(dlen) in struct hci_sco_hdr */
		.reserve = 8,
	},
};

/* Called from HCI core to initialize the device */
static int ti_st_open(struct hci_dev *hdev)
{
	unsigned long timeleft;
	struct ti_st *hst;
	int err, i;

	BT_DBG("%s %p", hdev->name, hdev);

	/* provide contexts for callbacks from ST */
	hst = hci_get_drvdata(hdev);

	for (i = 0; i < MAX_BT_CHNL_IDS; i++) {
		ti_st_proto[i].priv_data = hst;
		ti_st_proto[i].max_frame_size = HCI_MAX_FRAME_SIZE;
		ti_st_proto[i].recv = st_receive;
		ti_st_proto[i].reg_complete_cb = st_reg_completion_cb;

		/* Prepare wait-for-completion handler */
		init_completion(&hst->wait_reg_completion);
		/* Reset ST registration callback status flag,
		 * this value will be updated in
		 * st_reg_completion_cb()
		 * function whenever it called from ST driver.
		 */
		hst->reg_status = -EINPROGRESS;

		err = st_register(&ti_st_proto[i]);
		if (!err)
			goto done;

		if (err != -EINPROGRESS) {
			BT_ERR("st_register failed %d", err);
			return err;
		}

		/* ST is busy with either protocol
		 * registration or firmware download.
		 */
		BT_DBG("waiting for registration "
				"completion signal from ST");
		timeleft = wait_for_completion_timeout
			(&hst->wait_reg_completion,
			 msecs_to_jiffies(BT_REGISTER_TIMEOUT));
		if (!timeleft) {
			BT_ERR("Timeout(%d sec),didn't get reg "
					"completion signal from ST",
					BT_REGISTER_TIMEOUT / 1000);
			return -ETIMEDOUT;
		}

		/* Is ST registration callback
		 * called with ERROR status?
		 */
		if (hst->reg_status != 0) {
			BT_ERR("ST registration completed with invalid "
					"status %d", hst->reg_status);
			return -EAGAIN;
		}

done:
		hst->st_write = ti_st_proto[i].write;
		if (!hst->st_write) {
			BT_ERR("undefined ST write function");
			for (i = 0; i < MAX_BT_CHNL_IDS; i++) {
				/* Undo registration with ST */
				err = st_unregister(&ti_st_proto[i]);
				if (err)
					BT_ERR("st_unregister() failed with "
							"error %d", err);
				hst->st_write = NULL;
			}
			return -EIO;
		}
	}
	return 0;
}

/* Close device */
static int ti_st_close(struct hci_dev *hdev)
{
	int err, i;
	struct ti_st *hst = hci_get_drvdata(hdev);

	for (i = MAX_BT_CHNL_IDS-1; i >= 0; i--) {
		err = st_unregister(&ti_st_proto[i]);
		if (err)
			BT_ERR("st_unregister(%d) failed with error %d",
					ti_st_proto[i].chnl_id, err);
	}

	hst->st_write = NULL;

	return err;
}

static int ti_st_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
{
	struct ti_st *hst;
	long len;
	int pkt_type;

	hst = hci_get_drvdata(hdev);

	/* Prepend skb with frame type */
	memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);

	BT_DBG("%s: type %d len %d", hdev->name, hci_skb_pkt_type(skb),
	       skb->len);

	/* Insert skb to shared transport layer's transmit queue.
	 * Freeing skb memory is taken care in shared transport layer,
	 * so don't free skb memory here.
	 */
	pkt_type = hci_skb_pkt_type(skb);
	len = hst->st_write(skb);
	if (len < 0) {
		BT_ERR("ST write failed (%ld)", len);
		/* Try Again, would only fail if UART has gone bad */
		return -EAGAIN;
	}

	/* ST accepted our skb. So, Go ahead and do rest */
	hdev->stat.byte_tx += len;
	ti_st_tx_complete(hst, pkt_type);

	return 0;
}

static int bt_ti_probe(struct platform_device *pdev)
{
	struct ti_st *hst;
	struct hci_dev *hdev;
	int err;

	hst = devm_kzalloc(&pdev->dev, sizeof(struct ti_st), GFP_KERNEL);
	if (!hst)
		return -ENOMEM;

	/* Expose "hciX" device to user space */
	hdev = hci_alloc_dev();
	if (!hdev)
		return -ENOMEM;

	BT_DBG("hdev %p", hdev);

	hst->hdev = hdev;
	hdev->bus = HCI_UART;
	hci_set_drvdata(hdev, hst);
	hdev->open = ti_st_open;
	hdev->close = ti_st_close;
	hdev->flush = NULL;
	hdev->send = ti_st_send_frame;

	err = hci_register_dev(hdev);
	if (err < 0) {
		BT_ERR("Can't register HCI device error %d", err);
		hci_free_dev(hdev);
		return err;
	}

	BT_DBG("HCI device registered (hdev %p)", hdev);

	dev_set_drvdata(&pdev->dev, hst);
	return 0;
}

static int bt_ti_remove(struct platform_device *pdev)
{
	struct hci_dev *hdev;
	struct ti_st *hst = dev_get_drvdata(&pdev->dev);

	if (!hst)
		return -EFAULT;

	BT_DBG("%s", hst->hdev->name);

	hdev = hst->hdev;
	ti_st_close(hdev);
	hci_unregister_dev(hdev);

	hci_free_dev(hdev);

	dev_set_drvdata(&pdev->dev, NULL);
	return 0;
}

static struct platform_driver btwilink_driver = {
	.probe = bt_ti_probe,
	.remove = bt_ti_remove,
	.driver = {
		.name = "btwilink",
	},
};

module_platform_driver(btwilink_driver);

/* ------ Module Info ------ */

MODULE_AUTHOR("Raja Mani <raja_mani@ti.com>");
MODULE_DESCRIPTION("Bluetooth Driver for TI Shared Transport" VERSION);
MODULE_VERSION(VERSION);
MODULE_LICENSE("GPL");