xref: /linux/drivers/bluetooth/btmtkuart.c (revision e3966940559d52aa1800a008dcfeec218dd31f88)
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 <linux/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/pinctrl/consumer.h>
21 #include <linux/pm_runtime.h>
22 #include <linux/regulator/consumer.h>
23 #include <linux/serdev.h>
24 #include <linux/skbuff.h>
25 #include <linux/usb.h>
26 
27 #include <net/bluetooth/bluetooth.h>
28 #include <net/bluetooth/hci_core.h>
29 
30 #include "hci_uart.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 	struct hci_uart hu;
83 };
84 
85 #define btmtkuart_is_standalone(bdev)	\
86 	((bdev)->data->flags & BTMTKUART_FLAG_STANDALONE_HW)
87 #define btmtkuart_is_builtin_soc(bdev)	\
88 	!((bdev)->data->flags & BTMTKUART_FLAG_STANDALONE_HW)
89 
90 static int mtk_hci_wmt_sync(struct hci_dev *hdev,
91 			    struct btmtk_hci_wmt_params *wmt_params)
92 {
93 	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
94 	struct btmtk_hci_wmt_evt_funcc *wmt_evt_funcc;
95 	u32 hlen, status = BTMTK_WMT_INVALID;
96 	struct btmtk_hci_wmt_evt *wmt_evt;
97 	struct btmtk_hci_wmt_cmd *wc;
98 	struct btmtk_wmt_hdr *hdr;
99 	int err;
100 
101 	/* Send the WMT command and wait until the WMT event returns */
102 	hlen = sizeof(*hdr) + wmt_params->dlen;
103 	if (hlen > 255) {
104 		err = -EINVAL;
105 		goto err_free_skb;
106 	}
107 
108 	wc = kzalloc(hlen, GFP_KERNEL);
109 	if (!wc) {
110 		err = -ENOMEM;
111 		goto err_free_skb;
112 	}
113 
114 	hdr = &wc->hdr;
115 	hdr->dir = 1;
116 	hdr->op = wmt_params->op;
117 	hdr->dlen = cpu_to_le16(wmt_params->dlen + 1);
118 	hdr->flag = wmt_params->flag;
119 	memcpy(wc->data, wmt_params->data, wmt_params->dlen);
120 
121 	set_bit(BTMTKUART_TX_WAIT_VND_EVT, &bdev->tx_state);
122 
123 	err = __hci_cmd_send(hdev, 0xfc6f, hlen, wc);
124 	if (err < 0) {
125 		clear_bit(BTMTKUART_TX_WAIT_VND_EVT, &bdev->tx_state);
126 		goto err_free_wc;
127 	}
128 
129 	/* The vendor specific WMT commands are all answered by a vendor
130 	 * specific event and will not have the Command Status or Command
131 	 * Complete as with usual HCI command flow control.
132 	 *
133 	 * After sending the command, wait for BTMTKUART_TX_WAIT_VND_EVT
134 	 * state to be cleared. The driver specific event receive routine
135 	 * will clear that state and with that indicate completion of the
136 	 * WMT command.
137 	 */
138 	err = wait_on_bit_timeout(&bdev->tx_state, BTMTKUART_TX_WAIT_VND_EVT,
139 				  TASK_INTERRUPTIBLE, HCI_INIT_TIMEOUT);
140 	if (err == -EINTR) {
141 		bt_dev_err(hdev, "Execution of wmt command interrupted");
142 		clear_bit(BTMTKUART_TX_WAIT_VND_EVT, &bdev->tx_state);
143 		goto err_free_wc;
144 	}
145 
146 	if (err) {
147 		bt_dev_err(hdev, "Execution of wmt command timed out");
148 		clear_bit(BTMTKUART_TX_WAIT_VND_EVT, &bdev->tx_state);
149 		err = -ETIMEDOUT;
150 		goto err_free_wc;
151 	}
152 
153 	/* Parse and handle the return WMT event */
154 	wmt_evt = (struct btmtk_hci_wmt_evt *)bdev->evt_skb->data;
155 	if (wmt_evt->whdr.op != hdr->op) {
156 		bt_dev_err(hdev, "Wrong op received %d expected %d",
157 			   wmt_evt->whdr.op, hdr->op);
158 		err = -EIO;
159 		goto err_free_wc;
160 	}
161 
162 	switch (wmt_evt->whdr.op) {
163 	case BTMTK_WMT_SEMAPHORE:
164 		if (wmt_evt->whdr.flag == 2)
165 			status = BTMTK_WMT_PATCH_UNDONE;
166 		else
167 			status = BTMTK_WMT_PATCH_DONE;
168 		break;
169 	case BTMTK_WMT_FUNC_CTRL:
170 		wmt_evt_funcc = (struct btmtk_hci_wmt_evt_funcc *)wmt_evt;
171 		if (be16_to_cpu(wmt_evt_funcc->status) == 0x404)
172 			status = BTMTK_WMT_ON_DONE;
173 		else if (be16_to_cpu(wmt_evt_funcc->status) == 0x420)
174 			status = BTMTK_WMT_ON_PROGRESS;
175 		else
176 			status = BTMTK_WMT_ON_UNDONE;
177 		break;
178 	}
179 
180 	if (wmt_params->status)
181 		*wmt_params->status = status;
182 
183 err_free_wc:
184 	kfree(wc);
185 err_free_skb:
186 	kfree_skb(bdev->evt_skb);
187 	bdev->evt_skb = NULL;
188 
189 	return err;
190 }
191 
192 static int btmtkuart_recv_event(struct hci_dev *hdev, struct sk_buff *skb)
193 {
194 	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
195 	struct hci_event_hdr *hdr = (void *)skb->data;
196 	int err;
197 
198 	/* When someone waits for the WMT event, the skb is being cloned
199 	 * and being processed the events from there then.
200 	 */
201 	if (test_bit(BTMTKUART_TX_WAIT_VND_EVT, &bdev->tx_state)) {
202 		bdev->evt_skb = skb_clone(skb, GFP_KERNEL);
203 		if (!bdev->evt_skb) {
204 			err = -ENOMEM;
205 			goto err_out;
206 		}
207 	}
208 
209 	err = hci_recv_frame(hdev, skb);
210 	if (err < 0)
211 		goto err_free_skb;
212 
213 	if (hdr->evt == HCI_EV_WMT) {
214 		if (test_and_clear_bit(BTMTKUART_TX_WAIT_VND_EVT,
215 				       &bdev->tx_state)) {
216 			/* Barrier to sync with other CPUs */
217 			smp_mb__after_atomic();
218 			wake_up_bit(&bdev->tx_state, BTMTKUART_TX_WAIT_VND_EVT);
219 		}
220 	}
221 
222 	return 0;
223 
224 err_free_skb:
225 	kfree_skb(bdev->evt_skb);
226 	bdev->evt_skb = NULL;
227 
228 err_out:
229 	return err;
230 }
231 
232 static const struct h4_recv_pkt mtk_recv_pkts[] = {
233 	{ H4_RECV_ACL,      .recv = hci_recv_frame },
234 	{ H4_RECV_SCO,      .recv = hci_recv_frame },
235 	{ H4_RECV_EVENT,    .recv = btmtkuart_recv_event },
236 };
237 
238 static void btmtkuart_tx_work(struct work_struct *work)
239 {
240 	struct btmtkuart_dev *bdev = container_of(work, struct btmtkuart_dev,
241 						   tx_work);
242 	struct serdev_device *serdev = bdev->serdev;
243 	struct hci_dev *hdev = bdev->hdev;
244 
245 	while (1) {
246 		clear_bit(BTMTKUART_TX_STATE_WAKEUP, &bdev->tx_state);
247 
248 		while (1) {
249 			struct sk_buff *skb = skb_dequeue(&bdev->txq);
250 			int len;
251 
252 			if (!skb)
253 				break;
254 
255 			len = serdev_device_write_buf(serdev, skb->data,
256 						      skb->len);
257 			hdev->stat.byte_tx += len;
258 
259 			skb_pull(skb, len);
260 			if (skb->len > 0) {
261 				skb_queue_head(&bdev->txq, skb);
262 				break;
263 			}
264 
265 			switch (hci_skb_pkt_type(skb)) {
266 			case HCI_COMMAND_PKT:
267 				hdev->stat.cmd_tx++;
268 				break;
269 			case HCI_ACLDATA_PKT:
270 				hdev->stat.acl_tx++;
271 				break;
272 			case HCI_SCODATA_PKT:
273 				hdev->stat.sco_tx++;
274 				break;
275 			}
276 
277 			kfree_skb(skb);
278 		}
279 
280 		if (!test_bit(BTMTKUART_TX_STATE_WAKEUP, &bdev->tx_state))
281 			break;
282 	}
283 
284 	clear_bit(BTMTKUART_TX_STATE_ACTIVE, &bdev->tx_state);
285 }
286 
287 static void btmtkuart_tx_wakeup(struct btmtkuart_dev *bdev)
288 {
289 	if (test_and_set_bit(BTMTKUART_TX_STATE_ACTIVE, &bdev->tx_state))
290 		set_bit(BTMTKUART_TX_STATE_WAKEUP, &bdev->tx_state);
291 
292 	schedule_work(&bdev->tx_work);
293 }
294 
295 static const unsigned char *
296 mtk_stp_split(struct btmtkuart_dev *bdev, const unsigned char *data, int count,
297 	      int *sz_h4)
298 {
299 	struct mtk_stp_hdr *shdr;
300 
301 	/* The cursor is reset when all the data of STP is consumed out */
302 	if (!bdev->stp_dlen && bdev->stp_cursor >= 6)
303 		bdev->stp_cursor = 0;
304 
305 	/* Filling pad until all STP info is obtained */
306 	while (bdev->stp_cursor < 6 && count > 0) {
307 		bdev->stp_pad[bdev->stp_cursor] = *data;
308 		bdev->stp_cursor++;
309 		data++;
310 		count--;
311 	}
312 
313 	/* Retrieve STP info and have a sanity check */
314 	if (!bdev->stp_dlen && bdev->stp_cursor >= 6) {
315 		shdr = (struct mtk_stp_hdr *)&bdev->stp_pad[2];
316 		bdev->stp_dlen = be16_to_cpu(shdr->dlen) & 0x0fff;
317 
318 		/* Resync STP when unexpected data is being read */
319 		if (shdr->prefix != 0x80 || bdev->stp_dlen > 2048) {
320 			bt_dev_err(bdev->hdev, "stp format unexpected (%d, %d)",
321 				   shdr->prefix, bdev->stp_dlen);
322 			bdev->stp_cursor = 2;
323 			bdev->stp_dlen = 0;
324 		}
325 	}
326 
327 	/* Directly quit when there's no data found for H4 can process */
328 	if (count <= 0)
329 		return NULL;
330 
331 	/* Translate to how much the size of data H4 can handle so far */
332 	*sz_h4 = min_t(int, count, bdev->stp_dlen);
333 
334 	/* Update the remaining size of STP packet */
335 	bdev->stp_dlen -= *sz_h4;
336 
337 	/* Data points to STP payload which can be handled by H4 */
338 	return data;
339 }
340 
341 static void btmtkuart_recv(struct hci_dev *hdev, const u8 *data, size_t count)
342 {
343 	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
344 	const unsigned char *p_left = data, *p_h4;
345 	int sz_left = count, sz_h4, adv;
346 	int err;
347 
348 	while (sz_left > 0) {
349 		/*  The serial data received from MT7622 BT controller is
350 		 *  at all time padded around with the STP header and tailer.
351 		 *
352 		 *  A full STP packet is looking like
353 		 *   -----------------------------------
354 		 *  | STP header  |  H:4   | STP tailer |
355 		 *   -----------------------------------
356 		 *  but it doesn't guarantee to contain a full H:4 packet which
357 		 *  means that it's possible for multiple STP packets forms a
358 		 *  full H:4 packet that means extra STP header + length doesn't
359 		 *  indicate a full H:4 frame, things can fragment. Whose length
360 		 *  recorded in STP header just shows up the most length the
361 		 *  H:4 engine can handle currently.
362 		 */
363 
364 		p_h4 = mtk_stp_split(bdev, p_left, sz_left, &sz_h4);
365 		if (!p_h4)
366 			break;
367 
368 		adv = p_h4 - p_left;
369 		sz_left -= adv;
370 		p_left += adv;
371 
372 		bdev->rx_skb = h4_recv_buf(&bdev->hu, bdev->rx_skb, p_h4,
373 					   sz_h4, mtk_recv_pkts,
374 					   ARRAY_SIZE(mtk_recv_pkts));
375 		if (IS_ERR(bdev->rx_skb)) {
376 			err = PTR_ERR(bdev->rx_skb);
377 			bt_dev_err(bdev->hdev,
378 				   "Frame reassembly failed (%d)", err);
379 			bdev->rx_skb = NULL;
380 			return;
381 		}
382 
383 		sz_left -= sz_h4;
384 		p_left += sz_h4;
385 	}
386 }
387 
388 static size_t btmtkuart_receive_buf(struct serdev_device *serdev,
389 				    const u8 *data, size_t count)
390 {
391 	struct btmtkuart_dev *bdev = serdev_device_get_drvdata(serdev);
392 
393 	btmtkuart_recv(bdev->hdev, data, count);
394 
395 	bdev->hdev->stat.byte_rx += count;
396 
397 	return count;
398 }
399 
400 static void btmtkuart_write_wakeup(struct serdev_device *serdev)
401 {
402 	struct btmtkuart_dev *bdev = serdev_device_get_drvdata(serdev);
403 
404 	btmtkuart_tx_wakeup(bdev);
405 }
406 
407 static const struct serdev_device_ops btmtkuart_client_ops = {
408 	.receive_buf = btmtkuart_receive_buf,
409 	.write_wakeup = btmtkuart_write_wakeup,
410 };
411 
412 static int btmtkuart_open(struct hci_dev *hdev)
413 {
414 	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
415 	struct device *dev;
416 	int err;
417 
418 	err = serdev_device_open(bdev->serdev);
419 	if (err) {
420 		bt_dev_err(hdev, "Unable to open UART device %s",
421 			   dev_name(&bdev->serdev->dev));
422 		goto err_open;
423 	}
424 
425 	if (btmtkuart_is_standalone(bdev)) {
426 		if (bdev->curr_speed != bdev->desired_speed)
427 			err = serdev_device_set_baudrate(bdev->serdev,
428 							 115200);
429 		else
430 			err = serdev_device_set_baudrate(bdev->serdev,
431 							 bdev->desired_speed);
432 
433 		if (err < 0) {
434 			bt_dev_err(hdev, "Unable to set baudrate UART device %s",
435 				   dev_name(&bdev->serdev->dev));
436 			goto  err_serdev_close;
437 		}
438 
439 		serdev_device_set_flow_control(bdev->serdev, false);
440 	}
441 
442 	bdev->stp_cursor = 2;
443 	bdev->stp_dlen = 0;
444 
445 	dev = &bdev->serdev->dev;
446 
447 	/* Enable the power domain and clock the device requires */
448 	pm_runtime_enable(dev);
449 	err = pm_runtime_resume_and_get(dev);
450 	if (err < 0)
451 		goto err_disable_rpm;
452 
453 	err = clk_prepare_enable(bdev->clk);
454 	if (err < 0)
455 		goto err_put_rpm;
456 
457 	return 0;
458 
459 err_put_rpm:
460 	pm_runtime_put_sync(dev);
461 err_disable_rpm:
462 	pm_runtime_disable(dev);
463 err_serdev_close:
464 	serdev_device_close(bdev->serdev);
465 err_open:
466 	return err;
467 }
468 
469 static int btmtkuart_close(struct hci_dev *hdev)
470 {
471 	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
472 	struct device *dev = &bdev->serdev->dev;
473 
474 	/* Shutdown the clock and power domain the device requires */
475 	clk_disable_unprepare(bdev->clk);
476 	pm_runtime_put_sync(dev);
477 	pm_runtime_disable(dev);
478 
479 	serdev_device_close(bdev->serdev);
480 
481 	return 0;
482 }
483 
484 static int btmtkuart_flush(struct hci_dev *hdev)
485 {
486 	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
487 
488 	/* Flush any pending characters */
489 	serdev_device_write_flush(bdev->serdev);
490 	skb_queue_purge(&bdev->txq);
491 
492 	cancel_work_sync(&bdev->tx_work);
493 
494 	kfree_skb(bdev->rx_skb);
495 	bdev->rx_skb = NULL;
496 
497 	bdev->stp_cursor = 2;
498 	bdev->stp_dlen = 0;
499 
500 	return 0;
501 }
502 
503 static int btmtkuart_func_query(struct hci_dev *hdev)
504 {
505 	struct btmtk_hci_wmt_params wmt_params;
506 	int status, err;
507 	u8 param = 0;
508 
509 	/* Query whether the function is enabled */
510 	wmt_params.op = BTMTK_WMT_FUNC_CTRL;
511 	wmt_params.flag = 4;
512 	wmt_params.dlen = sizeof(param);
513 	wmt_params.data = &param;
514 	wmt_params.status = &status;
515 
516 	err = mtk_hci_wmt_sync(hdev, &wmt_params);
517 	if (err < 0) {
518 		bt_dev_err(hdev, "Failed to query function status (%d)", err);
519 		return err;
520 	}
521 
522 	return status;
523 }
524 
525 static int btmtkuart_change_baudrate(struct hci_dev *hdev)
526 {
527 	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
528 	struct btmtk_hci_wmt_params wmt_params;
529 	__le32 baudrate;
530 	u8 param;
531 	int err;
532 
533 	/* Indicate the device to enter the probe state the host is
534 	 * ready to change a new baudrate.
535 	 */
536 	baudrate = cpu_to_le32(bdev->desired_speed);
537 	wmt_params.op = BTMTK_WMT_HIF;
538 	wmt_params.flag = 1;
539 	wmt_params.dlen = 4;
540 	wmt_params.data = &baudrate;
541 	wmt_params.status = NULL;
542 
543 	err = mtk_hci_wmt_sync(hdev, &wmt_params);
544 	if (err < 0) {
545 		bt_dev_err(hdev, "Failed to device baudrate (%d)", err);
546 		return err;
547 	}
548 
549 	err = serdev_device_set_baudrate(bdev->serdev,
550 					 bdev->desired_speed);
551 	if (err < 0) {
552 		bt_dev_err(hdev, "Failed to set up host baudrate (%d)",
553 			   err);
554 		return err;
555 	}
556 
557 	serdev_device_set_flow_control(bdev->serdev, false);
558 
559 	/* Send a dummy byte 0xff to activate the new baudrate */
560 	param = 0xff;
561 	err = serdev_device_write_buf(bdev->serdev, &param, sizeof(param));
562 	if (err < 0 || err < sizeof(param))
563 		return err;
564 
565 	serdev_device_wait_until_sent(bdev->serdev, 0);
566 
567 	/* Wait some time for the device changing baudrate done */
568 	usleep_range(20000, 22000);
569 
570 	/* Test the new baudrate */
571 	wmt_params.op = BTMTK_WMT_TEST;
572 	wmt_params.flag = 7;
573 	wmt_params.dlen = 0;
574 	wmt_params.data = NULL;
575 	wmt_params.status = NULL;
576 
577 	err = mtk_hci_wmt_sync(hdev, &wmt_params);
578 	if (err < 0) {
579 		bt_dev_err(hdev, "Failed to test new baudrate (%d)",
580 			   err);
581 		return err;
582 	}
583 
584 	bdev->curr_speed = bdev->desired_speed;
585 
586 	return 0;
587 }
588 
589 static int btmtkuart_setup(struct hci_dev *hdev)
590 {
591 	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
592 	struct btmtk_hci_wmt_params wmt_params;
593 	ktime_t calltime, delta, rettime;
594 	struct btmtk_tci_sleep tci_sleep;
595 	unsigned long long duration;
596 	struct sk_buff *skb;
597 	int err, status;
598 	u8 param = 0x1;
599 
600 	calltime = ktime_get();
601 
602 	/* Wakeup MCUSYS is required for certain devices before we start to
603 	 * do any setups.
604 	 */
605 	if (test_bit(BTMTKUART_REQUIRED_WAKEUP, &bdev->tx_state)) {
606 		wmt_params.op = BTMTK_WMT_WAKEUP;
607 		wmt_params.flag = 3;
608 		wmt_params.dlen = 0;
609 		wmt_params.data = NULL;
610 		wmt_params.status = NULL;
611 
612 		err = mtk_hci_wmt_sync(hdev, &wmt_params);
613 		if (err < 0) {
614 			bt_dev_err(hdev, "Failed to wakeup the chip (%d)", err);
615 			return err;
616 		}
617 
618 		clear_bit(BTMTKUART_REQUIRED_WAKEUP, &bdev->tx_state);
619 	}
620 
621 	if (btmtkuart_is_standalone(bdev))
622 		btmtkuart_change_baudrate(hdev);
623 
624 	/* Query whether the firmware is already download */
625 	wmt_params.op = BTMTK_WMT_SEMAPHORE;
626 	wmt_params.flag = 1;
627 	wmt_params.dlen = 0;
628 	wmt_params.data = NULL;
629 	wmt_params.status = &status;
630 
631 	err = mtk_hci_wmt_sync(hdev, &wmt_params);
632 	if (err < 0) {
633 		bt_dev_err(hdev, "Failed to query firmware status (%d)", err);
634 		return err;
635 	}
636 
637 	if (status == BTMTK_WMT_PATCH_DONE) {
638 		bt_dev_info(hdev, "Firmware already downloaded");
639 		goto ignore_setup_fw;
640 	}
641 
642 	/* Setup a firmware which the device definitely requires */
643 	err = btmtk_setup_firmware(hdev, bdev->data->fwname, mtk_hci_wmt_sync);
644 	if (err < 0)
645 		return err;
646 
647 ignore_setup_fw:
648 	/* Query whether the device is already enabled */
649 	err = readx_poll_timeout(btmtkuart_func_query, hdev, status,
650 				 status < 0 || status != BTMTK_WMT_ON_PROGRESS,
651 				 2000, 5000000);
652 	/* -ETIMEDOUT happens */
653 	if (err < 0)
654 		return err;
655 
656 	/* The other errors happen in btusb_mtk_func_query */
657 	if (status < 0)
658 		return status;
659 
660 	if (status == BTMTK_WMT_ON_DONE) {
661 		bt_dev_info(hdev, "function already on");
662 		goto ignore_func_on;
663 	}
664 
665 	/* Enable Bluetooth protocol */
666 	wmt_params.op = BTMTK_WMT_FUNC_CTRL;
667 	wmt_params.flag = 0;
668 	wmt_params.dlen = sizeof(param);
669 	wmt_params.data = &param;
670 	wmt_params.status = NULL;
671 
672 	err = mtk_hci_wmt_sync(hdev, &wmt_params);
673 	if (err < 0) {
674 		bt_dev_err(hdev, "Failed to send wmt func ctrl (%d)", err);
675 		return err;
676 	}
677 
678 ignore_func_on:
679 	/* Apply the low power environment setup */
680 	tci_sleep.mode = 0x5;
681 	tci_sleep.duration = cpu_to_le16(0x640);
682 	tci_sleep.host_duration = cpu_to_le16(0x640);
683 	tci_sleep.host_wakeup_pin = 0;
684 	tci_sleep.time_compensation = 0;
685 
686 	skb = __hci_cmd_sync(hdev, 0xfc7a, sizeof(tci_sleep), &tci_sleep,
687 			     HCI_INIT_TIMEOUT);
688 	if (IS_ERR(skb)) {
689 		err = PTR_ERR(skb);
690 		bt_dev_err(hdev, "Failed to apply low power setting (%d)", err);
691 		return err;
692 	}
693 	kfree_skb(skb);
694 
695 	rettime = ktime_get();
696 	delta = ktime_sub(rettime, calltime);
697 	duration = (unsigned long long)ktime_to_ns(delta) >> 10;
698 
699 	bt_dev_info(hdev, "Device setup in %llu usecs", duration);
700 
701 	return 0;
702 }
703 
704 static int btmtkuart_shutdown(struct hci_dev *hdev)
705 {
706 	struct btmtk_hci_wmt_params wmt_params;
707 	u8 param = 0x0;
708 	int err;
709 
710 	/* Disable the device */
711 	wmt_params.op = BTMTK_WMT_FUNC_CTRL;
712 	wmt_params.flag = 0;
713 	wmt_params.dlen = sizeof(param);
714 	wmt_params.data = &param;
715 	wmt_params.status = NULL;
716 
717 	err = mtk_hci_wmt_sync(hdev, &wmt_params);
718 	if (err < 0) {
719 		bt_dev_err(hdev, "Failed to send wmt func ctrl (%d)", err);
720 		return err;
721 	}
722 
723 	return 0;
724 }
725 
726 static int btmtkuart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
727 {
728 	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
729 	struct mtk_stp_hdr *shdr;
730 	int err, dlen, type = 0;
731 
732 	/* Prepend skb with frame type */
733 	memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);
734 
735 	/* Make sure that there is enough rooms for STP header and trailer */
736 	if (unlikely(skb_headroom(skb) < sizeof(*shdr)) ||
737 	    (skb_tailroom(skb) < MTK_STP_TLR_SIZE)) {
738 		err = pskb_expand_head(skb, sizeof(*shdr), MTK_STP_TLR_SIZE,
739 				       GFP_ATOMIC);
740 		if (err < 0)
741 			return err;
742 	}
743 
744 	/* Add the STP header */
745 	dlen = skb->len;
746 	shdr = skb_push(skb, sizeof(*shdr));
747 	shdr->prefix = 0x80;
748 	shdr->dlen = cpu_to_be16((dlen & 0x0fff) | (type << 12));
749 	shdr->cs = 0;		/* MT7622 doesn't care about checksum value */
750 
751 	/* Add the STP trailer */
752 	skb_put_zero(skb, MTK_STP_TLR_SIZE);
753 
754 	skb_queue_tail(&bdev->txq, skb);
755 
756 	btmtkuart_tx_wakeup(bdev);
757 	return 0;
758 }
759 
760 static int btmtkuart_parse_dt(struct serdev_device *serdev)
761 {
762 	struct btmtkuart_dev *bdev = serdev_device_get_drvdata(serdev);
763 	struct device_node *node = serdev->dev.of_node;
764 	u32 speed = 921600;
765 	int err;
766 
767 	if (btmtkuart_is_standalone(bdev)) {
768 		of_property_read_u32(node, "current-speed", &speed);
769 
770 		bdev->desired_speed = speed;
771 
772 		bdev->vcc = devm_regulator_get(&serdev->dev, "vcc");
773 		if (IS_ERR(bdev->vcc)) {
774 			err = PTR_ERR(bdev->vcc);
775 			return err;
776 		}
777 
778 		bdev->osc = devm_clk_get_optional(&serdev->dev, "osc");
779 		if (IS_ERR(bdev->osc)) {
780 			err = PTR_ERR(bdev->osc);
781 			return err;
782 		}
783 
784 		bdev->boot = devm_gpiod_get_optional(&serdev->dev, "boot",
785 						     GPIOD_OUT_LOW);
786 		if (IS_ERR(bdev->boot)) {
787 			err = PTR_ERR(bdev->boot);
788 			return err;
789 		}
790 
791 		bdev->pinctrl = devm_pinctrl_get(&serdev->dev);
792 		if (IS_ERR(bdev->pinctrl)) {
793 			err = PTR_ERR(bdev->pinctrl);
794 			return err;
795 		}
796 
797 		bdev->pins_boot = pinctrl_lookup_state(bdev->pinctrl,
798 						       "default");
799 		if (IS_ERR(bdev->pins_boot) && !bdev->boot) {
800 			err = PTR_ERR(bdev->pins_boot);
801 			dev_err(&serdev->dev,
802 				"Should assign RXD to LOW at boot stage\n");
803 			return err;
804 		}
805 
806 		bdev->pins_runtime = pinctrl_lookup_state(bdev->pinctrl,
807 							  "runtime");
808 		if (IS_ERR(bdev->pins_runtime)) {
809 			err = PTR_ERR(bdev->pins_runtime);
810 			return err;
811 		}
812 
813 		bdev->reset = devm_gpiod_get_optional(&serdev->dev, "reset",
814 						      GPIOD_OUT_LOW);
815 		if (IS_ERR(bdev->reset)) {
816 			err = PTR_ERR(bdev->reset);
817 			return err;
818 		}
819 	} else if (btmtkuart_is_builtin_soc(bdev)) {
820 		bdev->clk = devm_clk_get(&serdev->dev, "ref");
821 		if (IS_ERR(bdev->clk))
822 			return PTR_ERR(bdev->clk);
823 	}
824 
825 	return 0;
826 }
827 
828 static int btmtkuart_probe(struct serdev_device *serdev)
829 {
830 	struct btmtkuart_dev *bdev;
831 	struct hci_dev *hdev;
832 	int err;
833 
834 	bdev = devm_kzalloc(&serdev->dev, sizeof(*bdev), GFP_KERNEL);
835 	if (!bdev)
836 		return -ENOMEM;
837 
838 	bdev->data = of_device_get_match_data(&serdev->dev);
839 	if (!bdev->data)
840 		return -ENODEV;
841 
842 	bdev->serdev = serdev;
843 	serdev_device_set_drvdata(serdev, bdev);
844 
845 	serdev_device_set_client_ops(serdev, &btmtkuart_client_ops);
846 
847 	err = btmtkuart_parse_dt(serdev);
848 	if (err < 0)
849 		return err;
850 
851 	INIT_WORK(&bdev->tx_work, btmtkuart_tx_work);
852 	skb_queue_head_init(&bdev->txq);
853 
854 	/* Initialize and register HCI device */
855 	hdev = hci_alloc_dev();
856 	if (!hdev) {
857 		dev_err(&serdev->dev, "Can't allocate HCI device\n");
858 		return -ENOMEM;
859 	}
860 
861 	bdev->hdev = hdev;
862 	bdev->hu.hdev = hdev;
863 
864 	hdev->bus = HCI_UART;
865 	hci_set_drvdata(hdev, bdev);
866 
867 	hdev->open     = btmtkuart_open;
868 	hdev->close    = btmtkuart_close;
869 	hdev->flush    = btmtkuart_flush;
870 	hdev->setup    = btmtkuart_setup;
871 	hdev->shutdown = btmtkuart_shutdown;
872 	hdev->send     = btmtkuart_send_frame;
873 	hdev->set_bdaddr = btmtk_set_bdaddr;
874 	SET_HCIDEV_DEV(hdev, &serdev->dev);
875 
876 	hdev->manufacturer = 70;
877 	hci_set_quirk(hdev, HCI_QUIRK_NON_PERSISTENT_SETUP);
878 
879 	if (btmtkuart_is_standalone(bdev)) {
880 		err = clk_prepare_enable(bdev->osc);
881 		if (err < 0)
882 			goto err_hci_free_dev;
883 
884 		if (bdev->boot) {
885 			gpiod_set_value_cansleep(bdev->boot, 1);
886 		} else {
887 			/* Switch to the specific pin state for the booting
888 			 * requires.
889 			 */
890 			pinctrl_select_state(bdev->pinctrl, bdev->pins_boot);
891 		}
892 
893 		/* Power on */
894 		err = regulator_enable(bdev->vcc);
895 		if (err < 0)
896 			goto err_clk_disable_unprepare;
897 
898 		/* Reset if the reset-gpios is available otherwise the board
899 		 * -level design should be guaranteed.
900 		 */
901 		if (bdev->reset) {
902 			gpiod_set_value_cansleep(bdev->reset, 1);
903 			usleep_range(1000, 2000);
904 			gpiod_set_value_cansleep(bdev->reset, 0);
905 		}
906 
907 		/* Wait some time until device got ready and switch to the pin
908 		 * mode the device requires for UART transfers.
909 		 */
910 		msleep(50);
911 
912 		if (bdev->boot)
913 			devm_gpiod_put(&serdev->dev, bdev->boot);
914 
915 		pinctrl_select_state(bdev->pinctrl, bdev->pins_runtime);
916 
917 		/* A standalone device doesn't depends on power domain on SoC,
918 		 * so mark it as no callbacks.
919 		 */
920 		pm_runtime_no_callbacks(&serdev->dev);
921 
922 		set_bit(BTMTKUART_REQUIRED_WAKEUP, &bdev->tx_state);
923 	}
924 
925 	err = hci_register_dev(hdev);
926 	if (err < 0) {
927 		dev_err(&serdev->dev, "Can't register HCI device\n");
928 		goto err_regulator_disable;
929 	}
930 
931 	return 0;
932 
933 err_regulator_disable:
934 	if (btmtkuart_is_standalone(bdev))
935 		regulator_disable(bdev->vcc);
936 err_clk_disable_unprepare:
937 	if (btmtkuart_is_standalone(bdev))
938 		clk_disable_unprepare(bdev->osc);
939 err_hci_free_dev:
940 	hci_free_dev(hdev);
941 
942 	return err;
943 }
944 
945 static void btmtkuart_remove(struct serdev_device *serdev)
946 {
947 	struct btmtkuart_dev *bdev = serdev_device_get_drvdata(serdev);
948 	struct hci_dev *hdev = bdev->hdev;
949 
950 	if (btmtkuart_is_standalone(bdev)) {
951 		regulator_disable(bdev->vcc);
952 		clk_disable_unprepare(bdev->osc);
953 	}
954 
955 	hci_unregister_dev(hdev);
956 	hci_free_dev(hdev);
957 }
958 
959 static const struct btmtkuart_data mt7622_data __maybe_unused = {
960 	.fwname = FIRMWARE_MT7622,
961 };
962 
963 static const struct btmtkuart_data mt7663_data __maybe_unused = {
964 	.flags = BTMTKUART_FLAG_STANDALONE_HW,
965 	.fwname = FIRMWARE_MT7663,
966 };
967 
968 static const struct btmtkuart_data mt7668_data __maybe_unused = {
969 	.flags = BTMTKUART_FLAG_STANDALONE_HW,
970 	.fwname = FIRMWARE_MT7668,
971 };
972 
973 #ifdef CONFIG_OF
974 static const struct of_device_id mtk_of_match_table[] = {
975 	{ .compatible = "mediatek,mt7622-bluetooth", .data = &mt7622_data},
976 	{ .compatible = "mediatek,mt7663u-bluetooth", .data = &mt7663_data},
977 	{ .compatible = "mediatek,mt7668u-bluetooth", .data = &mt7668_data},
978 	{ }
979 };
980 MODULE_DEVICE_TABLE(of, mtk_of_match_table);
981 #endif
982 
983 static struct serdev_device_driver btmtkuart_driver = {
984 	.probe = btmtkuart_probe,
985 	.remove = btmtkuart_remove,
986 	.driver = {
987 		.name = "btmtkuart",
988 		.of_match_table = of_match_ptr(mtk_of_match_table),
989 	},
990 };
991 
992 module_serdev_device_driver(btmtkuart_driver);
993 
994 MODULE_AUTHOR("Sean Wang <sean.wang@mediatek.com>");
995 MODULE_DESCRIPTION("MediaTek Bluetooth Serial driver ver " VERSION);
996 MODULE_VERSION(VERSION);
997 MODULE_LICENSE("GPL");
998