1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Texas Instrument's Bluetooth Driver For Shared Transport.
4 *
5 * Bluetooth Driver acts as interface between HCI core and
6 * TI Shared Transport Layer.
7 *
8 * Copyright (C) 2009-2010 Texas Instruments
9 * Author: Raja Mani <raja_mani@ti.com>
10 * Pavan Savoy <pavan_savoy@ti.com>
11 */
12
13 #include <linux/platform_device.h>
14 #include <net/bluetooth/bluetooth.h>
15 #include <net/bluetooth/hci_core.h>
16 #include <net/bluetooth/hci.h>
17
18 #include <linux/ti_wilink_st.h>
19 #include <linux/module.h>
20
21 /* Bluetooth Driver Version */
22 #define VERSION "1.0"
23 #define MAX_BT_CHNL_IDS 3
24
25 /* Number of seconds to wait for registration completion
26 * when ST returns PENDING status.
27 */
28 #define BT_REGISTER_TIMEOUT 6000 /* 6 sec */
29
30 /**
31 * struct ti_st - driver operation structure
32 * @hdev: hci device pointer which binds to bt driver
33 * @reg_status: ST registration callback status
34 * @st_write: write function provided by the ST driver
35 * to be used by the driver during send_frame.
36 * @wait_reg_completion - completion sync between ti_st_open
37 * and st_reg_completion_cb.
38 */
39 struct ti_st {
40 struct hci_dev *hdev;
41 int reg_status;
42 long (*st_write) (struct sk_buff *);
43 struct completion wait_reg_completion;
44 };
45
46 /* Increments HCI counters based on pocket ID (cmd,acl,sco) */
ti_st_tx_complete(struct ti_st * hst,int pkt_type)47 static inline void ti_st_tx_complete(struct ti_st *hst, int pkt_type)
48 {
49 struct hci_dev *hdev = hst->hdev;
50
51 /* Update HCI stat counters */
52 switch (pkt_type) {
53 case HCI_COMMAND_PKT:
54 hdev->stat.cmd_tx++;
55 break;
56
57 case HCI_ACLDATA_PKT:
58 hdev->stat.acl_tx++;
59 break;
60
61 case HCI_SCODATA_PKT:
62 hdev->stat.sco_tx++;
63 break;
64 }
65 }
66
67 /* ------- Interfaces to Shared Transport ------ */
68
69 /* Called by ST layer to indicate protocol registration completion
70 * status.ti_st_open() function will wait for signal from this
71 * API when st_register() function returns ST_PENDING.
72 */
st_reg_completion_cb(void * priv_data,int data)73 static void st_reg_completion_cb(void *priv_data, int data)
74 {
75 struct ti_st *lhst = priv_data;
76
77 /* Save registration status for use in ti_st_open() */
78 lhst->reg_status = data;
79 /* complete the wait in ti_st_open() */
80 complete(&lhst->wait_reg_completion);
81 }
82
83 /* Called by Shared Transport layer when receive data is available */
st_receive(void * priv_data,struct sk_buff * skb)84 static long st_receive(void *priv_data, struct sk_buff *skb)
85 {
86 struct ti_st *lhst = priv_data;
87 int err;
88
89 if (!skb)
90 return -EFAULT;
91
92 if (!lhst) {
93 kfree_skb(skb);
94 return -EFAULT;
95 }
96
97 /* Forward skb to HCI core layer */
98 err = hci_recv_frame(lhst->hdev, skb);
99 if (err < 0) {
100 BT_ERR("Unable to push skb to HCI core(%d)", err);
101 return err;
102 }
103
104 lhst->hdev->stat.byte_rx += skb->len;
105
106 return 0;
107 }
108
109 /* ------- Interfaces to HCI layer ------ */
110 /* protocol structure registered with shared transport */
111 static struct st_proto_s ti_st_proto[MAX_BT_CHNL_IDS] = {
112 {
113 .chnl_id = HCI_EVENT_PKT, /* HCI Events */
114 .hdr_len = sizeof(struct hci_event_hdr),
115 .offset_len_in_hdr = offsetof(struct hci_event_hdr, plen),
116 .len_size = 1, /* sizeof(plen) in struct hci_event_hdr */
117 .reserve = 8,
118 },
119 {
120 .chnl_id = HCI_ACLDATA_PKT, /* ACL */
121 .hdr_len = sizeof(struct hci_acl_hdr),
122 .offset_len_in_hdr = offsetof(struct hci_acl_hdr, dlen),
123 .len_size = 2, /* sizeof(dlen) in struct hci_acl_hdr */
124 .reserve = 8,
125 },
126 {
127 .chnl_id = HCI_SCODATA_PKT, /* SCO */
128 .hdr_len = sizeof(struct hci_sco_hdr),
129 .offset_len_in_hdr = offsetof(struct hci_sco_hdr, dlen),
130 .len_size = 1, /* sizeof(dlen) in struct hci_sco_hdr */
131 .reserve = 8,
132 },
133 };
134
135 /* Called from HCI core to initialize the device */
ti_st_open(struct hci_dev * hdev)136 static int ti_st_open(struct hci_dev *hdev)
137 {
138 unsigned long timeleft;
139 struct ti_st *hst;
140 int err, i;
141
142 BT_DBG("%s %p", hdev->name, hdev);
143
144 /* provide contexts for callbacks from ST */
145 hst = hci_get_drvdata(hdev);
146
147 for (i = 0; i < MAX_BT_CHNL_IDS; i++) {
148 ti_st_proto[i].priv_data = hst;
149 ti_st_proto[i].max_frame_size = HCI_MAX_FRAME_SIZE;
150 ti_st_proto[i].recv = st_receive;
151 ti_st_proto[i].reg_complete_cb = st_reg_completion_cb;
152
153 /* Prepare wait-for-completion handler */
154 init_completion(&hst->wait_reg_completion);
155 /* Reset ST registration callback status flag,
156 * this value will be updated in
157 * st_reg_completion_cb()
158 * function whenever it called from ST driver.
159 */
160 hst->reg_status = -EINPROGRESS;
161
162 err = st_register(&ti_st_proto[i]);
163 if (!err)
164 goto done;
165
166 if (err != -EINPROGRESS) {
167 BT_ERR("st_register failed %d", err);
168 return err;
169 }
170
171 /* ST is busy with either protocol
172 * registration or firmware download.
173 */
174 BT_DBG("waiting for registration "
175 "completion signal from ST");
176 timeleft = wait_for_completion_timeout
177 (&hst->wait_reg_completion,
178 msecs_to_jiffies(BT_REGISTER_TIMEOUT));
179 if (!timeleft) {
180 BT_ERR("Timeout(%d sec),didn't get reg "
181 "completion signal from ST",
182 BT_REGISTER_TIMEOUT / 1000);
183 return -ETIMEDOUT;
184 }
185
186 /* Is ST registration callback
187 * called with ERROR status?
188 */
189 if (hst->reg_status != 0) {
190 BT_ERR("ST registration completed with invalid "
191 "status %d", hst->reg_status);
192 return -EAGAIN;
193 }
194
195 done:
196 hst->st_write = ti_st_proto[i].write;
197 if (!hst->st_write) {
198 BT_ERR("undefined ST write function");
199 for (i = 0; i < MAX_BT_CHNL_IDS; i++) {
200 /* Undo registration with ST */
201 err = st_unregister(&ti_st_proto[i]);
202 if (err)
203 BT_ERR("st_unregister() failed with "
204 "error %d", err);
205 hst->st_write = NULL;
206 }
207 return -EIO;
208 }
209 }
210 return 0;
211 }
212
213 /* Close device */
ti_st_close(struct hci_dev * hdev)214 static int ti_st_close(struct hci_dev *hdev)
215 {
216 int err, i;
217 struct ti_st *hst = hci_get_drvdata(hdev);
218
219 for (i = MAX_BT_CHNL_IDS-1; i >= 0; i--) {
220 err = st_unregister(&ti_st_proto[i]);
221 if (err)
222 BT_ERR("st_unregister(%d) failed with error %d",
223 ti_st_proto[i].chnl_id, err);
224 }
225
226 hst->st_write = NULL;
227
228 return err;
229 }
230
ti_st_send_frame(struct hci_dev * hdev,struct sk_buff * skb)231 static int ti_st_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
232 {
233 struct ti_st *hst;
234 long len;
235 int pkt_type;
236
237 hst = hci_get_drvdata(hdev);
238
239 /* Prepend skb with frame type */
240 memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);
241
242 BT_DBG("%s: type %d len %d", hdev->name, hci_skb_pkt_type(skb),
243 skb->len);
244
245 /* Insert skb to shared transport layer's transmit queue.
246 * Freeing skb memory is taken care in shared transport layer,
247 * so don't free skb memory here.
248 */
249 pkt_type = hci_skb_pkt_type(skb);
250 len = hst->st_write(skb);
251 if (len < 0) {
252 BT_ERR("ST write failed (%ld)", len);
253 /* Try Again, would only fail if UART has gone bad */
254 return -EAGAIN;
255 }
256
257 /* ST accepted our skb. So, Go ahead and do rest */
258 hdev->stat.byte_tx += len;
259 ti_st_tx_complete(hst, pkt_type);
260
261 return 0;
262 }
263
bt_ti_probe(struct platform_device * pdev)264 static int bt_ti_probe(struct platform_device *pdev)
265 {
266 struct ti_st *hst;
267 struct hci_dev *hdev;
268 int err;
269
270 hst = devm_kzalloc(&pdev->dev, sizeof(struct ti_st), GFP_KERNEL);
271 if (!hst)
272 return -ENOMEM;
273
274 /* Expose "hciX" device to user space */
275 hdev = hci_alloc_dev();
276 if (!hdev)
277 return -ENOMEM;
278
279 BT_DBG("hdev %p", hdev);
280
281 hst->hdev = hdev;
282 hdev->bus = HCI_UART;
283 hci_set_drvdata(hdev, hst);
284 hdev->open = ti_st_open;
285 hdev->close = ti_st_close;
286 hdev->flush = NULL;
287 hdev->send = ti_st_send_frame;
288
289 err = hci_register_dev(hdev);
290 if (err < 0) {
291 BT_ERR("Can't register HCI device error %d", err);
292 hci_free_dev(hdev);
293 return err;
294 }
295
296 BT_DBG("HCI device registered (hdev %p)", hdev);
297
298 dev_set_drvdata(&pdev->dev, hst);
299 return 0;
300 }
301
bt_ti_remove(struct platform_device * pdev)302 static int bt_ti_remove(struct platform_device *pdev)
303 {
304 struct hci_dev *hdev;
305 struct ti_st *hst = dev_get_drvdata(&pdev->dev);
306
307 if (!hst)
308 return -EFAULT;
309
310 BT_DBG("%s", hst->hdev->name);
311
312 hdev = hst->hdev;
313 ti_st_close(hdev);
314 hci_unregister_dev(hdev);
315
316 hci_free_dev(hdev);
317
318 dev_set_drvdata(&pdev->dev, NULL);
319 return 0;
320 }
321
322 static struct platform_driver btwilink_driver = {
323 .probe = bt_ti_probe,
324 .remove = bt_ti_remove,
325 .driver = {
326 .name = "btwilink",
327 },
328 };
329
330 module_platform_driver(btwilink_driver);
331
332 /* ------ Module Info ------ */
333
334 MODULE_AUTHOR("Raja Mani <raja_mani@ti.com>");
335 MODULE_DESCRIPTION("Bluetooth Driver for TI Shared Transport" VERSION);
336 MODULE_VERSION(VERSION);
337 MODULE_LICENSE("GPL");
338