xref: /openbmc/linux/drivers/bluetooth/btmtkuart.c (revision 9a29f5fc)
1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (c) 2018 MediaTek Inc.
3 
4 /*
5  * Bluetooth support for MediaTek serial devices
6  *
7  * Author: Sean Wang <sean.wang@mediatek.com>
8  *
9  */
10 
11 #include <asm/unaligned.h>
12 #include <linux/atomic.h>
13 #include <linux/clk.h>
14 #include <linux/firmware.h>
15 #include <linux/gpio/consumer.h>
16 #include <linux/iopoll.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/of.h>
20 #include <linux/of_device.h>
21 #include <linux/pinctrl/consumer.h>
22 #include <linux/pm_runtime.h>
23 #include <linux/regulator/consumer.h>
24 #include <linux/serdev.h>
25 #include <linux/skbuff.h>
26 
27 #include <net/bluetooth/bluetooth.h>
28 #include <net/bluetooth/hci_core.h>
29 
30 #include "h4_recv.h"
31 #include "btmtk.h"
32 
33 #define VERSION "0.2"
34 
35 #define MTK_STP_TLR_SIZE	2
36 
37 #define BTMTKUART_TX_STATE_ACTIVE	1
38 #define BTMTKUART_TX_STATE_WAKEUP	2
39 #define BTMTKUART_TX_WAIT_VND_EVT	3
40 #define BTMTKUART_REQUIRED_WAKEUP	4
41 
42 #define BTMTKUART_FLAG_STANDALONE_HW	 BIT(0)
43 
44 struct mtk_stp_hdr {
45 	u8	prefix;
46 	__be16	dlen;
47 	u8	cs;
48 } __packed;
49 
50 struct btmtkuart_data {
51 	unsigned int flags;
52 	const char *fwname;
53 };
54 
55 struct btmtkuart_dev {
56 	struct hci_dev *hdev;
57 	struct serdev_device *serdev;
58 
59 	struct clk *clk;
60 	struct clk *osc;
61 	struct regulator *vcc;
62 	struct gpio_desc *reset;
63 	struct gpio_desc *boot;
64 	struct pinctrl *pinctrl;
65 	struct pinctrl_state *pins_runtime;
66 	struct pinctrl_state *pins_boot;
67 	speed_t	desired_speed;
68 	speed_t	curr_speed;
69 
70 	struct work_struct tx_work;
71 	unsigned long tx_state;
72 	struct sk_buff_head txq;
73 
74 	struct sk_buff *rx_skb;
75 	struct sk_buff *evt_skb;
76 
77 	u8	stp_pad[6];
78 	u8	stp_cursor;
79 	u16	stp_dlen;
80 
81 	const struct btmtkuart_data *data;
82 };
83 
84 #define btmtkuart_is_standalone(bdev)	\
85 	((bdev)->data->flags & BTMTKUART_FLAG_STANDALONE_HW)
86 #define btmtkuart_is_builtin_soc(bdev)	\
87 	!((bdev)->data->flags & BTMTKUART_FLAG_STANDALONE_HW)
88 
89 static int mtk_hci_wmt_sync(struct hci_dev *hdev,
90 			    struct btmtk_hci_wmt_params *wmt_params)
91 {
92 	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
93 	struct btmtk_hci_wmt_evt_funcc *wmt_evt_funcc;
94 	u32 hlen, status = BTMTK_WMT_INVALID;
95 	struct btmtk_hci_wmt_evt *wmt_evt;
96 	struct btmtk_hci_wmt_cmd *wc;
97 	struct btmtk_wmt_hdr *hdr;
98 	int err;
99 
100 	/* Send the WMT command and wait until the WMT event returns */
101 	hlen = sizeof(*hdr) + wmt_params->dlen;
102 	if (hlen > 255) {
103 		err = -EINVAL;
104 		goto err_free_skb;
105 	}
106 
107 	wc = kzalloc(hlen, GFP_KERNEL);
108 	if (!wc) {
109 		err = -ENOMEM;
110 		goto err_free_skb;
111 	}
112 
113 	hdr = &wc->hdr;
114 	hdr->dir = 1;
115 	hdr->op = wmt_params->op;
116 	hdr->dlen = cpu_to_le16(wmt_params->dlen + 1);
117 	hdr->flag = wmt_params->flag;
118 	memcpy(wc->data, wmt_params->data, wmt_params->dlen);
119 
120 	set_bit(BTMTKUART_TX_WAIT_VND_EVT, &bdev->tx_state);
121 
122 	err = __hci_cmd_send(hdev, 0xfc6f, hlen, wc);
123 	if (err < 0) {
124 		clear_bit(BTMTKUART_TX_WAIT_VND_EVT, &bdev->tx_state);
125 		goto err_free_wc;
126 	}
127 
128 	/* The vendor specific WMT commands are all answered by a vendor
129 	 * specific event and will not have the Command Status or Command
130 	 * Complete as with usual HCI command flow control.
131 	 *
132 	 * After sending the command, wait for BTMTKUART_TX_WAIT_VND_EVT
133 	 * state to be cleared. The driver specific event receive routine
134 	 * will clear that state and with that indicate completion of the
135 	 * WMT command.
136 	 */
137 	err = wait_on_bit_timeout(&bdev->tx_state, BTMTKUART_TX_WAIT_VND_EVT,
138 				  TASK_INTERRUPTIBLE, HCI_INIT_TIMEOUT);
139 	if (err == -EINTR) {
140 		bt_dev_err(hdev, "Execution of wmt command interrupted");
141 		clear_bit(BTMTKUART_TX_WAIT_VND_EVT, &bdev->tx_state);
142 		goto err_free_wc;
143 	}
144 
145 	if (err) {
146 		bt_dev_err(hdev, "Execution of wmt command timed out");
147 		clear_bit(BTMTKUART_TX_WAIT_VND_EVT, &bdev->tx_state);
148 		err = -ETIMEDOUT;
149 		goto err_free_wc;
150 	}
151 
152 	/* Parse and handle the return WMT event */
153 	wmt_evt = (struct btmtk_hci_wmt_evt *)bdev->evt_skb->data;
154 	if (wmt_evt->whdr.op != hdr->op) {
155 		bt_dev_err(hdev, "Wrong op received %d expected %d",
156 			   wmt_evt->whdr.op, hdr->op);
157 		err = -EIO;
158 		goto err_free_wc;
159 	}
160 
161 	switch (wmt_evt->whdr.op) {
162 	case BTMTK_WMT_SEMAPHORE:
163 		if (wmt_evt->whdr.flag == 2)
164 			status = BTMTK_WMT_PATCH_UNDONE;
165 		else
166 			status = BTMTK_WMT_PATCH_DONE;
167 		break;
168 	case BTMTK_WMT_FUNC_CTRL:
169 		wmt_evt_funcc = (struct btmtk_hci_wmt_evt_funcc *)wmt_evt;
170 		if (be16_to_cpu(wmt_evt_funcc->status) == 0x404)
171 			status = BTMTK_WMT_ON_DONE;
172 		else if (be16_to_cpu(wmt_evt_funcc->status) == 0x420)
173 			status = BTMTK_WMT_ON_PROGRESS;
174 		else
175 			status = BTMTK_WMT_ON_UNDONE;
176 		break;
177 	}
178 
179 	if (wmt_params->status)
180 		*wmt_params->status = status;
181 
182 err_free_wc:
183 	kfree(wc);
184 err_free_skb:
185 	kfree_skb(bdev->evt_skb);
186 	bdev->evt_skb = NULL;
187 
188 	return err;
189 }
190 
191 static int btmtkuart_recv_event(struct hci_dev *hdev, struct sk_buff *skb)
192 {
193 	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
194 	struct hci_event_hdr *hdr = (void *)skb->data;
195 	int err;
196 
197 	/* When someone waits for the WMT event, the skb is being cloned
198 	 * and being processed the events from there then.
199 	 */
200 	if (test_bit(BTMTKUART_TX_WAIT_VND_EVT, &bdev->tx_state)) {
201 		bdev->evt_skb = skb_clone(skb, GFP_KERNEL);
202 		if (!bdev->evt_skb) {
203 			err = -ENOMEM;
204 			goto err_out;
205 		}
206 	}
207 
208 	err = hci_recv_frame(hdev, skb);
209 	if (err < 0)
210 		goto err_free_skb;
211 
212 	if (hdr->evt == HCI_EV_WMT) {
213 		if (test_and_clear_bit(BTMTKUART_TX_WAIT_VND_EVT,
214 				       &bdev->tx_state)) {
215 			/* Barrier to sync with other CPUs */
216 			smp_mb__after_atomic();
217 			wake_up_bit(&bdev->tx_state, BTMTKUART_TX_WAIT_VND_EVT);
218 		}
219 	}
220 
221 	return 0;
222 
223 err_free_skb:
224 	kfree_skb(bdev->evt_skb);
225 	bdev->evt_skb = NULL;
226 
227 err_out:
228 	return err;
229 }
230 
231 static const struct h4_recv_pkt mtk_recv_pkts[] = {
232 	{ H4_RECV_ACL,      .recv = hci_recv_frame },
233 	{ H4_RECV_SCO,      .recv = hci_recv_frame },
234 	{ H4_RECV_EVENT,    .recv = btmtkuart_recv_event },
235 };
236 
237 static void btmtkuart_tx_work(struct work_struct *work)
238 {
239 	struct btmtkuart_dev *bdev = container_of(work, struct btmtkuart_dev,
240 						   tx_work);
241 	struct serdev_device *serdev = bdev->serdev;
242 	struct hci_dev *hdev = bdev->hdev;
243 
244 	while (1) {
245 		clear_bit(BTMTKUART_TX_STATE_WAKEUP, &bdev->tx_state);
246 
247 		while (1) {
248 			struct sk_buff *skb = skb_dequeue(&bdev->txq);
249 			int len;
250 
251 			if (!skb)
252 				break;
253 
254 			len = serdev_device_write_buf(serdev, skb->data,
255 						      skb->len);
256 			hdev->stat.byte_tx += len;
257 
258 			skb_pull(skb, len);
259 			if (skb->len > 0) {
260 				skb_queue_head(&bdev->txq, skb);
261 				break;
262 			}
263 
264 			switch (hci_skb_pkt_type(skb)) {
265 			case HCI_COMMAND_PKT:
266 				hdev->stat.cmd_tx++;
267 				break;
268 			case HCI_ACLDATA_PKT:
269 				hdev->stat.acl_tx++;
270 				break;
271 			case HCI_SCODATA_PKT:
272 				hdev->stat.sco_tx++;
273 				break;
274 			}
275 
276 			kfree_skb(skb);
277 		}
278 
279 		if (!test_bit(BTMTKUART_TX_STATE_WAKEUP, &bdev->tx_state))
280 			break;
281 	}
282 
283 	clear_bit(BTMTKUART_TX_STATE_ACTIVE, &bdev->tx_state);
284 }
285 
286 static void btmtkuart_tx_wakeup(struct btmtkuart_dev *bdev)
287 {
288 	if (test_and_set_bit(BTMTKUART_TX_STATE_ACTIVE, &bdev->tx_state))
289 		set_bit(BTMTKUART_TX_STATE_WAKEUP, &bdev->tx_state);
290 
291 	schedule_work(&bdev->tx_work);
292 }
293 
294 static const unsigned char *
295 mtk_stp_split(struct btmtkuart_dev *bdev, const unsigned char *data, int count,
296 	      int *sz_h4)
297 {
298 	struct mtk_stp_hdr *shdr;
299 
300 	/* The cursor is reset when all the data of STP is consumed out */
301 	if (!bdev->stp_dlen && bdev->stp_cursor >= 6)
302 		bdev->stp_cursor = 0;
303 
304 	/* Filling pad until all STP info is obtained */
305 	while (bdev->stp_cursor < 6 && count > 0) {
306 		bdev->stp_pad[bdev->stp_cursor] = *data;
307 		bdev->stp_cursor++;
308 		data++;
309 		count--;
310 	}
311 
312 	/* Retrieve STP info and have a sanity check */
313 	if (!bdev->stp_dlen && bdev->stp_cursor >= 6) {
314 		shdr = (struct mtk_stp_hdr *)&bdev->stp_pad[2];
315 		bdev->stp_dlen = be16_to_cpu(shdr->dlen) & 0x0fff;
316 
317 		/* Resync STP when unexpected data is being read */
318 		if (shdr->prefix != 0x80 || bdev->stp_dlen > 2048) {
319 			bt_dev_err(bdev->hdev, "stp format unexpect (%d, %d)",
320 				   shdr->prefix, bdev->stp_dlen);
321 			bdev->stp_cursor = 2;
322 			bdev->stp_dlen = 0;
323 		}
324 	}
325 
326 	/* Directly quit when there's no data found for H4 can process */
327 	if (count <= 0)
328 		return NULL;
329 
330 	/* Tranlate to how much the size of data H4 can handle so far */
331 	*sz_h4 = min_t(int, count, bdev->stp_dlen);
332 
333 	/* Update the remaining size of STP packet */
334 	bdev->stp_dlen -= *sz_h4;
335 
336 	/* Data points to STP payload which can be handled by H4 */
337 	return data;
338 }
339 
340 static int btmtkuart_recv(struct hci_dev *hdev, const u8 *data, size_t count)
341 {
342 	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
343 	const unsigned char *p_left = data, *p_h4;
344 	int sz_left = count, sz_h4, adv;
345 	int err;
346 
347 	while (sz_left > 0) {
348 		/*  The serial data received from MT7622 BT controller is
349 		 *  at all time padded around with the STP header and tailer.
350 		 *
351 		 *  A full STP packet is looking like
352 		 *   -----------------------------------
353 		 *  | STP header  |  H:4   | STP tailer |
354 		 *   -----------------------------------
355 		 *  but it doesn't guarantee to contain a full H:4 packet which
356 		 *  means that it's possible for multiple STP packets forms a
357 		 *  full H:4 packet that means extra STP header + length doesn't
358 		 *  indicate a full H:4 frame, things can fragment. Whose length
359 		 *  recorded in STP header just shows up the most length the
360 		 *  H:4 engine can handle currently.
361 		 */
362 
363 		p_h4 = mtk_stp_split(bdev, p_left, sz_left, &sz_h4);
364 		if (!p_h4)
365 			break;
366 
367 		adv = p_h4 - p_left;
368 		sz_left -= adv;
369 		p_left += adv;
370 
371 		bdev->rx_skb = h4_recv_buf(bdev->hdev, bdev->rx_skb, p_h4,
372 					   sz_h4, mtk_recv_pkts,
373 					   ARRAY_SIZE(mtk_recv_pkts));
374 		if (IS_ERR(bdev->rx_skb)) {
375 			err = PTR_ERR(bdev->rx_skb);
376 			bt_dev_err(bdev->hdev,
377 				   "Frame reassembly failed (%d)", err);
378 			bdev->rx_skb = NULL;
379 			return err;
380 		}
381 
382 		sz_left -= sz_h4;
383 		p_left += sz_h4;
384 	}
385 
386 	return 0;
387 }
388 
389 static int btmtkuart_receive_buf(struct serdev_device *serdev, const u8 *data,
390 				 size_t count)
391 {
392 	struct btmtkuart_dev *bdev = serdev_device_get_drvdata(serdev);
393 	int err;
394 
395 	err = btmtkuart_recv(bdev->hdev, data, count);
396 	if (err < 0)
397 		return err;
398 
399 	bdev->hdev->stat.byte_rx += count;
400 
401 	return count;
402 }
403 
404 static void btmtkuart_write_wakeup(struct serdev_device *serdev)
405 {
406 	struct btmtkuart_dev *bdev = serdev_device_get_drvdata(serdev);
407 
408 	btmtkuart_tx_wakeup(bdev);
409 }
410 
411 static const struct serdev_device_ops btmtkuart_client_ops = {
412 	.receive_buf = btmtkuart_receive_buf,
413 	.write_wakeup = btmtkuart_write_wakeup,
414 };
415 
416 static int btmtkuart_open(struct hci_dev *hdev)
417 {
418 	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
419 	struct device *dev;
420 	int err;
421 
422 	err = serdev_device_open(bdev->serdev);
423 	if (err) {
424 		bt_dev_err(hdev, "Unable to open UART device %s",
425 			   dev_name(&bdev->serdev->dev));
426 		goto err_open;
427 	}
428 
429 	if (btmtkuart_is_standalone(bdev)) {
430 		if (bdev->curr_speed != bdev->desired_speed)
431 			err = serdev_device_set_baudrate(bdev->serdev,
432 							 115200);
433 		else
434 			err = serdev_device_set_baudrate(bdev->serdev,
435 							 bdev->desired_speed);
436 
437 		if (err < 0) {
438 			bt_dev_err(hdev, "Unable to set baudrate UART device %s",
439 				   dev_name(&bdev->serdev->dev));
440 			goto  err_serdev_close;
441 		}
442 
443 		serdev_device_set_flow_control(bdev->serdev, false);
444 	}
445 
446 	bdev->stp_cursor = 2;
447 	bdev->stp_dlen = 0;
448 
449 	dev = &bdev->serdev->dev;
450 
451 	/* Enable the power domain and clock the device requires */
452 	pm_runtime_enable(dev);
453 	err = pm_runtime_resume_and_get(dev);
454 	if (err < 0)
455 		goto err_disable_rpm;
456 
457 	err = clk_prepare_enable(bdev->clk);
458 	if (err < 0)
459 		goto err_put_rpm;
460 
461 	return 0;
462 
463 err_put_rpm:
464 	pm_runtime_put_sync(dev);
465 err_disable_rpm:
466 	pm_runtime_disable(dev);
467 err_serdev_close:
468 	serdev_device_close(bdev->serdev);
469 err_open:
470 	return err;
471 }
472 
473 static int btmtkuart_close(struct hci_dev *hdev)
474 {
475 	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
476 	struct device *dev = &bdev->serdev->dev;
477 
478 	/* Shutdown the clock and power domain the device requires */
479 	clk_disable_unprepare(bdev->clk);
480 	pm_runtime_put_sync(dev);
481 	pm_runtime_disable(dev);
482 
483 	serdev_device_close(bdev->serdev);
484 
485 	return 0;
486 }
487 
488 static int btmtkuart_flush(struct hci_dev *hdev)
489 {
490 	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
491 
492 	/* Flush any pending characters */
493 	serdev_device_write_flush(bdev->serdev);
494 	skb_queue_purge(&bdev->txq);
495 
496 	cancel_work_sync(&bdev->tx_work);
497 
498 	kfree_skb(bdev->rx_skb);
499 	bdev->rx_skb = NULL;
500 
501 	bdev->stp_cursor = 2;
502 	bdev->stp_dlen = 0;
503 
504 	return 0;
505 }
506 
507 static int btmtkuart_func_query(struct hci_dev *hdev)
508 {
509 	struct btmtk_hci_wmt_params wmt_params;
510 	int status, err;
511 	u8 param = 0;
512 
513 	/* Query whether the function is enabled */
514 	wmt_params.op = BTMTK_WMT_FUNC_CTRL;
515 	wmt_params.flag = 4;
516 	wmt_params.dlen = sizeof(param);
517 	wmt_params.data = &param;
518 	wmt_params.status = &status;
519 
520 	err = mtk_hci_wmt_sync(hdev, &wmt_params);
521 	if (err < 0) {
522 		bt_dev_err(hdev, "Failed to query function status (%d)", err);
523 		return err;
524 	}
525 
526 	return status;
527 }
528 
529 static int btmtkuart_change_baudrate(struct hci_dev *hdev)
530 {
531 	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
532 	struct btmtk_hci_wmt_params wmt_params;
533 	__le32 baudrate;
534 	u8 param;
535 	int err;
536 
537 	/* Indicate the device to enter the probe state the host is
538 	 * ready to change a new baudrate.
539 	 */
540 	baudrate = cpu_to_le32(bdev->desired_speed);
541 	wmt_params.op = BTMTK_WMT_HIF;
542 	wmt_params.flag = 1;
543 	wmt_params.dlen = 4;
544 	wmt_params.data = &baudrate;
545 	wmt_params.status = NULL;
546 
547 	err = mtk_hci_wmt_sync(hdev, &wmt_params);
548 	if (err < 0) {
549 		bt_dev_err(hdev, "Failed to device baudrate (%d)", err);
550 		return err;
551 	}
552 
553 	err = serdev_device_set_baudrate(bdev->serdev,
554 					 bdev->desired_speed);
555 	if (err < 0) {
556 		bt_dev_err(hdev, "Failed to set up host baudrate (%d)",
557 			   err);
558 		return err;
559 	}
560 
561 	serdev_device_set_flow_control(bdev->serdev, false);
562 
563 	/* Send a dummy byte 0xff to activate the new baudrate */
564 	param = 0xff;
565 	err = serdev_device_write_buf(bdev->serdev, &param, sizeof(param));
566 	if (err < 0 || err < sizeof(param))
567 		return err;
568 
569 	serdev_device_wait_until_sent(bdev->serdev, 0);
570 
571 	/* Wait some time for the device changing baudrate done */
572 	usleep_range(20000, 22000);
573 
574 	/* Test the new baudrate */
575 	wmt_params.op = BTMTK_WMT_TEST;
576 	wmt_params.flag = 7;
577 	wmt_params.dlen = 0;
578 	wmt_params.data = NULL;
579 	wmt_params.status = NULL;
580 
581 	err = mtk_hci_wmt_sync(hdev, &wmt_params);
582 	if (err < 0) {
583 		bt_dev_err(hdev, "Failed to test new baudrate (%d)",
584 			   err);
585 		return err;
586 	}
587 
588 	bdev->curr_speed = bdev->desired_speed;
589 
590 	return 0;
591 }
592 
593 static int btmtkuart_setup(struct hci_dev *hdev)
594 {
595 	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
596 	struct btmtk_hci_wmt_params wmt_params;
597 	ktime_t calltime, delta, rettime;
598 	struct btmtk_tci_sleep tci_sleep;
599 	unsigned long long duration;
600 	struct sk_buff *skb;
601 	int err, status;
602 	u8 param = 0x1;
603 
604 	calltime = ktime_get();
605 
606 	/* Wakeup MCUSYS is required for certain devices before we start to
607 	 * do any setups.
608 	 */
609 	if (test_bit(BTMTKUART_REQUIRED_WAKEUP, &bdev->tx_state)) {
610 		wmt_params.op = BTMTK_WMT_WAKEUP;
611 		wmt_params.flag = 3;
612 		wmt_params.dlen = 0;
613 		wmt_params.data = NULL;
614 		wmt_params.status = NULL;
615 
616 		err = mtk_hci_wmt_sync(hdev, &wmt_params);
617 		if (err < 0) {
618 			bt_dev_err(hdev, "Failed to wakeup the chip (%d)", err);
619 			return err;
620 		}
621 
622 		clear_bit(BTMTKUART_REQUIRED_WAKEUP, &bdev->tx_state);
623 	}
624 
625 	if (btmtkuart_is_standalone(bdev))
626 		btmtkuart_change_baudrate(hdev);
627 
628 	/* Query whether the firmware is already download */
629 	wmt_params.op = BTMTK_WMT_SEMAPHORE;
630 	wmt_params.flag = 1;
631 	wmt_params.dlen = 0;
632 	wmt_params.data = NULL;
633 	wmt_params.status = &status;
634 
635 	err = mtk_hci_wmt_sync(hdev, &wmt_params);
636 	if (err < 0) {
637 		bt_dev_err(hdev, "Failed to query firmware status (%d)", err);
638 		return err;
639 	}
640 
641 	if (status == BTMTK_WMT_PATCH_DONE) {
642 		bt_dev_info(hdev, "Firmware already downloaded");
643 		goto ignore_setup_fw;
644 	}
645 
646 	/* Setup a firmware which the device definitely requires */
647 	err = btmtk_setup_firmware(hdev, bdev->data->fwname, mtk_hci_wmt_sync);
648 	if (err < 0)
649 		return err;
650 
651 ignore_setup_fw:
652 	/* Query whether the device is already enabled */
653 	err = readx_poll_timeout(btmtkuart_func_query, hdev, status,
654 				 status < 0 || status != BTMTK_WMT_ON_PROGRESS,
655 				 2000, 5000000);
656 	/* -ETIMEDOUT happens */
657 	if (err < 0)
658 		return err;
659 
660 	/* The other errors happen in btusb_mtk_func_query */
661 	if (status < 0)
662 		return status;
663 
664 	if (status == BTMTK_WMT_ON_DONE) {
665 		bt_dev_info(hdev, "function already on");
666 		goto ignore_func_on;
667 	}
668 
669 	/* Enable Bluetooth protocol */
670 	wmt_params.op = BTMTK_WMT_FUNC_CTRL;
671 	wmt_params.flag = 0;
672 	wmt_params.dlen = sizeof(param);
673 	wmt_params.data = &param;
674 	wmt_params.status = NULL;
675 
676 	err = mtk_hci_wmt_sync(hdev, &wmt_params);
677 	if (err < 0) {
678 		bt_dev_err(hdev, "Failed to send wmt func ctrl (%d)", err);
679 		return err;
680 	}
681 
682 ignore_func_on:
683 	/* Apply the low power environment setup */
684 	tci_sleep.mode = 0x5;
685 	tci_sleep.duration = cpu_to_le16(0x640);
686 	tci_sleep.host_duration = cpu_to_le16(0x640);
687 	tci_sleep.host_wakeup_pin = 0;
688 	tci_sleep.time_compensation = 0;
689 
690 	skb = __hci_cmd_sync(hdev, 0xfc7a, sizeof(tci_sleep), &tci_sleep,
691 			     HCI_INIT_TIMEOUT);
692 	if (IS_ERR(skb)) {
693 		err = PTR_ERR(skb);
694 		bt_dev_err(hdev, "Failed to apply low power setting (%d)", err);
695 		return err;
696 	}
697 	kfree_skb(skb);
698 
699 	rettime = ktime_get();
700 	delta = ktime_sub(rettime, calltime);
701 	duration = (unsigned long long)ktime_to_ns(delta) >> 10;
702 
703 	bt_dev_info(hdev, "Device setup in %llu usecs", duration);
704 
705 	return 0;
706 }
707 
708 static int btmtkuart_shutdown(struct hci_dev *hdev)
709 {
710 	struct btmtk_hci_wmt_params wmt_params;
711 	u8 param = 0x0;
712 	int err;
713 
714 	/* Disable the device */
715 	wmt_params.op = BTMTK_WMT_FUNC_CTRL;
716 	wmt_params.flag = 0;
717 	wmt_params.dlen = sizeof(param);
718 	wmt_params.data = &param;
719 	wmt_params.status = NULL;
720 
721 	err = mtk_hci_wmt_sync(hdev, &wmt_params);
722 	if (err < 0) {
723 		bt_dev_err(hdev, "Failed to send wmt func ctrl (%d)", err);
724 		return err;
725 	}
726 
727 	return 0;
728 }
729 
730 static int btmtkuart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
731 {
732 	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
733 	struct mtk_stp_hdr *shdr;
734 	int err, dlen, type = 0;
735 
736 	/* Prepend skb with frame type */
737 	memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);
738 
739 	/* Make sure that there is enough rooms for STP header and trailer */
740 	if (unlikely(skb_headroom(skb) < sizeof(*shdr)) ||
741 	    (skb_tailroom(skb) < MTK_STP_TLR_SIZE)) {
742 		err = pskb_expand_head(skb, sizeof(*shdr), MTK_STP_TLR_SIZE,
743 				       GFP_ATOMIC);
744 		if (err < 0)
745 			return err;
746 	}
747 
748 	/* Add the STP header */
749 	dlen = skb->len;
750 	shdr = skb_push(skb, sizeof(*shdr));
751 	shdr->prefix = 0x80;
752 	shdr->dlen = cpu_to_be16((dlen & 0x0fff) | (type << 12));
753 	shdr->cs = 0;		/* MT7622 doesn't care about checksum value */
754 
755 	/* Add the STP trailer */
756 	skb_put_zero(skb, MTK_STP_TLR_SIZE);
757 
758 	skb_queue_tail(&bdev->txq, skb);
759 
760 	btmtkuart_tx_wakeup(bdev);
761 	return 0;
762 }
763 
764 static int btmtkuart_parse_dt(struct serdev_device *serdev)
765 {
766 	struct btmtkuart_dev *bdev = serdev_device_get_drvdata(serdev);
767 	struct device_node *node = serdev->dev.of_node;
768 	u32 speed = 921600;
769 	int err;
770 
771 	if (btmtkuart_is_standalone(bdev)) {
772 		of_property_read_u32(node, "current-speed", &speed);
773 
774 		bdev->desired_speed = speed;
775 
776 		bdev->vcc = devm_regulator_get(&serdev->dev, "vcc");
777 		if (IS_ERR(bdev->vcc)) {
778 			err = PTR_ERR(bdev->vcc);
779 			return err;
780 		}
781 
782 		bdev->osc = devm_clk_get_optional(&serdev->dev, "osc");
783 		if (IS_ERR(bdev->osc)) {
784 			err = PTR_ERR(bdev->osc);
785 			return err;
786 		}
787 
788 		bdev->boot = devm_gpiod_get_optional(&serdev->dev, "boot",
789 						     GPIOD_OUT_LOW);
790 		if (IS_ERR(bdev->boot)) {
791 			err = PTR_ERR(bdev->boot);
792 			return err;
793 		}
794 
795 		bdev->pinctrl = devm_pinctrl_get(&serdev->dev);
796 		if (IS_ERR(bdev->pinctrl)) {
797 			err = PTR_ERR(bdev->pinctrl);
798 			return err;
799 		}
800 
801 		bdev->pins_boot = pinctrl_lookup_state(bdev->pinctrl,
802 						       "default");
803 		if (IS_ERR(bdev->pins_boot) && !bdev->boot) {
804 			err = PTR_ERR(bdev->pins_boot);
805 			dev_err(&serdev->dev,
806 				"Should assign RXD to LOW at boot stage\n");
807 			return err;
808 		}
809 
810 		bdev->pins_runtime = pinctrl_lookup_state(bdev->pinctrl,
811 							  "runtime");
812 		if (IS_ERR(bdev->pins_runtime)) {
813 			err = PTR_ERR(bdev->pins_runtime);
814 			return err;
815 		}
816 
817 		bdev->reset = devm_gpiod_get_optional(&serdev->dev, "reset",
818 						      GPIOD_OUT_LOW);
819 		if (IS_ERR(bdev->reset)) {
820 			err = PTR_ERR(bdev->reset);
821 			return err;
822 		}
823 	} else if (btmtkuart_is_builtin_soc(bdev)) {
824 		bdev->clk = devm_clk_get(&serdev->dev, "ref");
825 		if (IS_ERR(bdev->clk))
826 			return PTR_ERR(bdev->clk);
827 	}
828 
829 	return 0;
830 }
831 
832 static int btmtkuart_probe(struct serdev_device *serdev)
833 {
834 	struct btmtkuart_dev *bdev;
835 	struct hci_dev *hdev;
836 	int err;
837 
838 	bdev = devm_kzalloc(&serdev->dev, sizeof(*bdev), GFP_KERNEL);
839 	if (!bdev)
840 		return -ENOMEM;
841 
842 	bdev->data = of_device_get_match_data(&serdev->dev);
843 	if (!bdev->data)
844 		return -ENODEV;
845 
846 	bdev->serdev = serdev;
847 	serdev_device_set_drvdata(serdev, bdev);
848 
849 	serdev_device_set_client_ops(serdev, &btmtkuart_client_ops);
850 
851 	err = btmtkuart_parse_dt(serdev);
852 	if (err < 0)
853 		return err;
854 
855 	INIT_WORK(&bdev->tx_work, btmtkuart_tx_work);
856 	skb_queue_head_init(&bdev->txq);
857 
858 	/* Initialize and register HCI device */
859 	hdev = hci_alloc_dev();
860 	if (!hdev) {
861 		dev_err(&serdev->dev, "Can't allocate HCI device\n");
862 		return -ENOMEM;
863 	}
864 
865 	bdev->hdev = hdev;
866 
867 	hdev->bus = HCI_UART;
868 	hci_set_drvdata(hdev, bdev);
869 
870 	hdev->open     = btmtkuart_open;
871 	hdev->close    = btmtkuart_close;
872 	hdev->flush    = btmtkuart_flush;
873 	hdev->setup    = btmtkuart_setup;
874 	hdev->shutdown = btmtkuart_shutdown;
875 	hdev->send     = btmtkuart_send_frame;
876 	hdev->set_bdaddr = btmtk_set_bdaddr;
877 	SET_HCIDEV_DEV(hdev, &serdev->dev);
878 
879 	hdev->manufacturer = 70;
880 	set_bit(HCI_QUIRK_NON_PERSISTENT_SETUP, &hdev->quirks);
881 
882 	if (btmtkuart_is_standalone(bdev)) {
883 		err = clk_prepare_enable(bdev->osc);
884 		if (err < 0)
885 			goto err_hci_free_dev;
886 
887 		if (bdev->boot) {
888 			gpiod_set_value_cansleep(bdev->boot, 1);
889 		} else {
890 			/* Switch to the specific pin state for the booting
891 			 * requires.
892 			 */
893 			pinctrl_select_state(bdev->pinctrl, bdev->pins_boot);
894 		}
895 
896 		/* Power on */
897 		err = regulator_enable(bdev->vcc);
898 		if (err < 0)
899 			goto err_clk_disable_unprepare;
900 
901 		/* Reset if the reset-gpios is available otherwise the board
902 		 * -level design should be guaranteed.
903 		 */
904 		if (bdev->reset) {
905 			gpiod_set_value_cansleep(bdev->reset, 1);
906 			usleep_range(1000, 2000);
907 			gpiod_set_value_cansleep(bdev->reset, 0);
908 		}
909 
910 		/* Wait some time until device got ready and switch to the pin
911 		 * mode the device requires for UART transfers.
912 		 */
913 		msleep(50);
914 
915 		if (bdev->boot)
916 			devm_gpiod_put(&serdev->dev, bdev->boot);
917 
918 		pinctrl_select_state(bdev->pinctrl, bdev->pins_runtime);
919 
920 		/* A standalone device doesn't depends on power domain on SoC,
921 		 * so mark it as no callbacks.
922 		 */
923 		pm_runtime_no_callbacks(&serdev->dev);
924 
925 		set_bit(BTMTKUART_REQUIRED_WAKEUP, &bdev->tx_state);
926 	}
927 
928 	err = hci_register_dev(hdev);
929 	if (err < 0) {
930 		dev_err(&serdev->dev, "Can't register HCI device\n");
931 		goto err_regulator_disable;
932 	}
933 
934 	return 0;
935 
936 err_regulator_disable:
937 	if (btmtkuart_is_standalone(bdev))
938 		regulator_disable(bdev->vcc);
939 err_clk_disable_unprepare:
940 	if (btmtkuart_is_standalone(bdev))
941 		clk_disable_unprepare(bdev->osc);
942 err_hci_free_dev:
943 	hci_free_dev(hdev);
944 
945 	return err;
946 }
947 
948 static void btmtkuart_remove(struct serdev_device *serdev)
949 {
950 	struct btmtkuart_dev *bdev = serdev_device_get_drvdata(serdev);
951 	struct hci_dev *hdev = bdev->hdev;
952 
953 	if (btmtkuart_is_standalone(bdev)) {
954 		regulator_disable(bdev->vcc);
955 		clk_disable_unprepare(bdev->osc);
956 	}
957 
958 	hci_unregister_dev(hdev);
959 	hci_free_dev(hdev);
960 }
961 
962 static const struct btmtkuart_data mt7622_data = {
963 	.fwname = FIRMWARE_MT7622,
964 };
965 
966 static const struct btmtkuart_data mt7663_data = {
967 	.flags = BTMTKUART_FLAG_STANDALONE_HW,
968 	.fwname = FIRMWARE_MT7663,
969 };
970 
971 static const struct btmtkuart_data mt7668_data = {
972 	.flags = BTMTKUART_FLAG_STANDALONE_HW,
973 	.fwname = FIRMWARE_MT7668,
974 };
975 
976 #ifdef CONFIG_OF
977 static const struct of_device_id mtk_of_match_table[] = {
978 	{ .compatible = "mediatek,mt7622-bluetooth", .data = &mt7622_data},
979 	{ .compatible = "mediatek,mt7663u-bluetooth", .data = &mt7663_data},
980 	{ .compatible = "mediatek,mt7668u-bluetooth", .data = &mt7668_data},
981 	{ }
982 };
983 MODULE_DEVICE_TABLE(of, mtk_of_match_table);
984 #endif
985 
986 static struct serdev_device_driver btmtkuart_driver = {
987 	.probe = btmtkuart_probe,
988 	.remove = btmtkuart_remove,
989 	.driver = {
990 		.name = "btmtkuart",
991 		.of_match_table = of_match_ptr(mtk_of_match_table),
992 	},
993 };
994 
995 module_serdev_device_driver(btmtkuart_driver);
996 
997 MODULE_AUTHOR("Sean Wang <sean.wang@mediatek.com>");
998 MODULE_DESCRIPTION("MediaTek Bluetooth Serial driver ver " VERSION);
999 MODULE_VERSION(VERSION);
1000 MODULE_LICENSE("GPL");
1001