Merge tag 'auxdisplay-for-linus-v5.12' of git://github.com/ojeda/linux
[linux-2.6-microblaze.git] / drivers / bluetooth / hci_serdev.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  Bluetooth HCI serdev driver lib
4  *
5  *  Copyright (C) 2017  Linaro, Ltd., Rob Herring <robh@kernel.org>
6  *
7  *  Based on hci_ldisc.c:
8  *
9  *  Copyright (C) 2000-2001  Qualcomm Incorporated
10  *  Copyright (C) 2002-2003  Maxim Krasnyansky <maxk@qualcomm.com>
11  *  Copyright (C) 2004-2005  Marcel Holtmann <marcel@holtmann.org>
12  */
13
14 #include <linux/kernel.h>
15 #include <linux/types.h>
16 #include <linux/serdev.h>
17 #include <linux/skbuff.h>
18
19 #include <net/bluetooth/bluetooth.h>
20 #include <net/bluetooth/hci_core.h>
21
22 #include "hci_uart.h"
23
24 static inline void hci_uart_tx_complete(struct hci_uart *hu, int pkt_type)
25 {
26         struct hci_dev *hdev = hu->hdev;
27
28         /* Update HCI stat counters */
29         switch (pkt_type) {
30         case HCI_COMMAND_PKT:
31                 hdev->stat.cmd_tx++;
32                 break;
33
34         case HCI_ACLDATA_PKT:
35                 hdev->stat.acl_tx++;
36                 break;
37
38         case HCI_SCODATA_PKT:
39                 hdev->stat.sco_tx++;
40                 break;
41         }
42 }
43
44 static inline struct sk_buff *hci_uart_dequeue(struct hci_uart *hu)
45 {
46         struct sk_buff *skb = hu->tx_skb;
47
48         if (!skb) {
49                 if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
50                         skb = hu->proto->dequeue(hu);
51         } else
52                 hu->tx_skb = NULL;
53
54         return skb;
55 }
56
57 static void hci_uart_write_work(struct work_struct *work)
58 {
59         struct hci_uart *hu = container_of(work, struct hci_uart, write_work);
60         struct serdev_device *serdev = hu->serdev;
61         struct hci_dev *hdev = hu->hdev;
62         struct sk_buff *skb;
63
64         /* REVISIT:
65          * should we cope with bad skbs or ->write() returning an error value?
66          */
67         do {
68                 clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
69
70                 while ((skb = hci_uart_dequeue(hu))) {
71                         int len;
72
73                         len = serdev_device_write_buf(serdev,
74                                                       skb->data, skb->len);
75                         hdev->stat.byte_tx += len;
76
77                         skb_pull(skb, len);
78                         if (skb->len) {
79                                 hu->tx_skb = skb;
80                                 break;
81                         }
82
83                         hci_uart_tx_complete(hu, hci_skb_pkt_type(skb));
84                         kfree_skb(skb);
85                 }
86
87                 clear_bit(HCI_UART_SENDING, &hu->tx_state);
88         } while (test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state));
89 }
90
91 /* ------- Interface to HCI layer ------ */
92
93 /* Reset device */
94 static int hci_uart_flush(struct hci_dev *hdev)
95 {
96         struct hci_uart *hu  = hci_get_drvdata(hdev);
97
98         BT_DBG("hdev %p serdev %p", hdev, hu->serdev);
99
100         if (hu->tx_skb) {
101                 kfree_skb(hu->tx_skb); hu->tx_skb = NULL;
102         }
103
104         /* Flush any pending characters in the driver and discipline. */
105         serdev_device_write_flush(hu->serdev);
106
107         if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
108                 hu->proto->flush(hu);
109
110         return 0;
111 }
112
113 /* Initialize device */
114 static int hci_uart_open(struct hci_dev *hdev)
115 {
116         struct hci_uart *hu = hci_get_drvdata(hdev);
117         int err;
118
119         BT_DBG("%s %p", hdev->name, hdev);
120
121         /* When Quirk HCI_QUIRK_NON_PERSISTENT_SETUP is set by
122          * driver, BT SoC is completely turned OFF during
123          * BT OFF. Upon next BT ON UART port should be opened.
124          */
125         if (!test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
126                 err = serdev_device_open(hu->serdev);
127                 if (err)
128                         return err;
129                 set_bit(HCI_UART_PROTO_READY, &hu->flags);
130         }
131
132         /* Undo clearing this from hci_uart_close() */
133         hdev->flush = hci_uart_flush;
134
135         return 0;
136 }
137
138 /* Close device */
139 static int hci_uart_close(struct hci_dev *hdev)
140 {
141         struct hci_uart *hu = hci_get_drvdata(hdev);
142
143         BT_DBG("hdev %p", hdev);
144
145         if (!test_bit(HCI_UART_PROTO_READY, &hu->flags))
146                 return 0;
147
148         hci_uart_flush(hdev);
149         hdev->flush = NULL;
150
151         /* When QUIRK HCI_QUIRK_NON_PERSISTENT_SETUP is set by driver,
152          * BT SOC is completely powered OFF during BT OFF, holding port
153          * open may drain the battery.
154          */
155         if (test_bit(HCI_QUIRK_NON_PERSISTENT_SETUP, &hdev->quirks)) {
156                 clear_bit(HCI_UART_PROTO_READY, &hu->flags);
157                 serdev_device_close(hu->serdev);
158         }
159
160         return 0;
161 }
162
163 /* Send frames from HCI layer */
164 static int hci_uart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
165 {
166         struct hci_uart *hu = hci_get_drvdata(hdev);
167
168         BT_DBG("%s: type %d len %d", hdev->name, hci_skb_pkt_type(skb),
169                skb->len);
170
171         hu->proto->enqueue(hu, skb);
172
173         hci_uart_tx_wakeup(hu);
174
175         return 0;
176 }
177
178 static int hci_uart_setup(struct hci_dev *hdev)
179 {
180         struct hci_uart *hu = hci_get_drvdata(hdev);
181         struct hci_rp_read_local_version *ver;
182         struct sk_buff *skb;
183         unsigned int speed;
184         int err;
185
186         /* Init speed if any */
187         if (hu->init_speed)
188                 speed = hu->init_speed;
189         else if (hu->proto->init_speed)
190                 speed = hu->proto->init_speed;
191         else
192                 speed = 0;
193
194         if (speed)
195                 serdev_device_set_baudrate(hu->serdev, speed);
196
197         /* Operational speed if any */
198         if (hu->oper_speed)
199                 speed = hu->oper_speed;
200         else if (hu->proto->oper_speed)
201                 speed = hu->proto->oper_speed;
202         else
203                 speed = 0;
204
205         if (hu->proto->set_baudrate && speed) {
206                 err = hu->proto->set_baudrate(hu, speed);
207                 if (err)
208                         bt_dev_err(hdev, "Failed to set baudrate");
209                 else
210                         serdev_device_set_baudrate(hu->serdev, speed);
211         }
212
213         if (hu->proto->setup)
214                 return hu->proto->setup(hu);
215
216         if (!test_bit(HCI_UART_VND_DETECT, &hu->hdev_flags))
217                 return 0;
218
219         skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
220                              HCI_INIT_TIMEOUT);
221         if (IS_ERR(skb)) {
222                 bt_dev_err(hdev, "Reading local version info failed (%ld)",
223                            PTR_ERR(skb));
224                 return 0;
225         }
226
227         if (skb->len != sizeof(*ver))
228                 bt_dev_err(hdev, "Event length mismatch for version info");
229
230         kfree_skb(skb);
231         return 0;
232 }
233
234 /** hci_uart_write_wakeup - transmit buffer wakeup
235  * @serdev: serial device
236  *
237  * This function is called by the serdev framework when it accepts
238  * more data being sent.
239  */
240 static void hci_uart_write_wakeup(struct serdev_device *serdev)
241 {
242         struct hci_uart *hu = serdev_device_get_drvdata(serdev);
243
244         BT_DBG("");
245
246         if (!hu || serdev != hu->serdev) {
247                 WARN_ON(1);
248                 return;
249         }
250
251         if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
252                 hci_uart_tx_wakeup(hu);
253 }
254
255 /** hci_uart_receive_buf - receive buffer wakeup
256  * @serdev: serial device
257  * @data:   pointer to received data
258  * @count:  count of received data in bytes
259  *
260  * This function is called by the serdev framework when it received data
261  * in the RX buffer.
262  *
263  * Return: number of processed bytes
264  */
265 static int hci_uart_receive_buf(struct serdev_device *serdev, const u8 *data,
266                                    size_t count)
267 {
268         struct hci_uart *hu = serdev_device_get_drvdata(serdev);
269
270         if (!hu || serdev != hu->serdev) {
271                 WARN_ON(1);
272                 return 0;
273         }
274
275         if (!test_bit(HCI_UART_PROTO_READY, &hu->flags))
276                 return 0;
277
278         /* It does not need a lock here as it is already protected by a mutex in
279          * tty caller
280          */
281         hu->proto->recv(hu, data, count);
282
283         if (hu->hdev)
284                 hu->hdev->stat.byte_rx += count;
285
286         return count;
287 }
288
289 static const struct serdev_device_ops hci_serdev_client_ops = {
290         .receive_buf = hci_uart_receive_buf,
291         .write_wakeup = hci_uart_write_wakeup,
292 };
293
294 int hci_uart_register_device(struct hci_uart *hu,
295                              const struct hci_uart_proto *p)
296 {
297         int err;
298         struct hci_dev *hdev;
299
300         BT_DBG("");
301
302         serdev_device_set_client_ops(hu->serdev, &hci_serdev_client_ops);
303
304         err = serdev_device_open(hu->serdev);
305         if (err)
306                 return err;
307
308         err = p->open(hu);
309         if (err)
310                 goto err_open;
311
312         hu->proto = p;
313         set_bit(HCI_UART_PROTO_READY, &hu->flags);
314
315         /* Initialize and register HCI device */
316         hdev = hci_alloc_dev();
317         if (!hdev) {
318                 BT_ERR("Can't allocate HCI device");
319                 err = -ENOMEM;
320                 goto err_alloc;
321         }
322
323         hu->hdev = hdev;
324
325         hdev->bus = HCI_UART;
326         hci_set_drvdata(hdev, hu);
327
328         INIT_WORK(&hu->init_ready, hci_uart_init_work);
329         INIT_WORK(&hu->write_work, hci_uart_write_work);
330         percpu_init_rwsem(&hu->proto_lock);
331
332         /* Only when vendor specific setup callback is provided, consider
333          * the manufacturer information valid. This avoids filling in the
334          * value for Ericsson when nothing is specified.
335          */
336         if (hu->proto->setup)
337                 hdev->manufacturer = hu->proto->manufacturer;
338
339         hdev->open  = hci_uart_open;
340         hdev->close = hci_uart_close;
341         hdev->flush = hci_uart_flush;
342         hdev->send  = hci_uart_send_frame;
343         hdev->setup = hci_uart_setup;
344         SET_HCIDEV_DEV(hdev, &hu->serdev->dev);
345
346         if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
347                 set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
348
349         if (test_bit(HCI_UART_EXT_CONFIG, &hu->hdev_flags))
350                 set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
351
352         if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
353                 hdev->dev_type = HCI_AMP;
354         else
355                 hdev->dev_type = HCI_PRIMARY;
356
357         if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
358                 return 0;
359
360         if (hci_register_dev(hdev) < 0) {
361                 BT_ERR("Can't register HCI device");
362                 err = -ENODEV;
363                 goto err_register;
364         }
365
366         set_bit(HCI_UART_REGISTERED, &hu->flags);
367
368         return 0;
369
370 err_register:
371         hci_free_dev(hdev);
372 err_alloc:
373         clear_bit(HCI_UART_PROTO_READY, &hu->flags);
374         p->close(hu);
375 err_open:
376         serdev_device_close(hu->serdev);
377         return err;
378 }
379 EXPORT_SYMBOL_GPL(hci_uart_register_device);
380
381 void hci_uart_unregister_device(struct hci_uart *hu)
382 {
383         struct hci_dev *hdev = hu->hdev;
384
385         cancel_work_sync(&hu->init_ready);
386         if (test_bit(HCI_UART_REGISTERED, &hu->flags))
387                 hci_unregister_dev(hdev);
388         hci_free_dev(hdev);
389
390         cancel_work_sync(&hu->write_work);
391
392         hu->proto->close(hu);
393
394         if (test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
395                 clear_bit(HCI_UART_PROTO_READY, &hu->flags);
396                 serdev_device_close(hu->serdev);
397         }
398 }
399 EXPORT_SYMBOL_GPL(hci_uart_unregister_device);