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1// SPDX-License-Identifier: GPL-2.02// Copyright (c) 2018 MediaTek Inc.3 4/*5 * Bluetooth support for MediaTek serial devices6 *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 "h4_recv.h"31#include "btmtk.h"32 33#define VERSION "0.2"34 35#define MTK_STP_TLR_SIZE	236 37#define BTMTKUART_TX_STATE_ACTIVE	138#define BTMTKUART_TX_STATE_WAKEUP	239#define BTMTKUART_TX_WAIT_VND_EVT	340#define BTMTKUART_REQUIRED_WAKEUP	441 42#define BTMTKUART_FLAG_STANDALONE_HW	 BIT(0)43 44struct mtk_stp_hdr {45	u8	prefix;46	__be16	dlen;47	u8	cs;48} __packed;49 50struct btmtkuart_data {51	unsigned int flags;52	const char *fwname;53};54 55struct 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 89static 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 vendor129	 * specific event and will not have the Command Status or Command130	 * Complete as with usual HCI command flow control.131	 *132	 * After sending the command, wait for BTMTKUART_TX_WAIT_VND_EVT133	 * state to be cleared. The driver specific event receive routine134	 * will clear that state and with that indicate completion of the135	 * 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		else166			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		else175			status = BTMTK_WMT_ON_UNDONE;176		break;177	}178 179	if (wmt_params->status)180		*wmt_params->status = status;181 182err_free_wc:183	kfree(wc);184err_free_skb:185	kfree_skb(bdev->evt_skb);186	bdev->evt_skb = NULL;187 188	return err;189}190 191static 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 cloned198	 * 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 223err_free_skb:224	kfree_skb(bdev->evt_skb);225	bdev->evt_skb = NULL;226 227err_out:228	return err;229}230 231static 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 237static 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 286static 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 294static const unsigned char *295mtk_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 340static void 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 is349		 *  at all time padded around with the STP header and tailer.350		 *351		 *  A full STP packet is looking like352		 *   -----------------------------------353		 *  | STP header  |  H:4   | STP tailer |354		 *   -----------------------------------355		 *  but it doesn't guarantee to contain a full H:4 packet which356		 *  means that it's possible for multiple STP packets forms a357		 *  full H:4 packet that means extra STP header + length doesn't358		 *  indicate a full H:4 frame, things can fragment. Whose length359		 *  recorded in STP header just shows up the most length the360		 *  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;380		}381 382		sz_left -= sz_h4;383		p_left += sz_h4;384	}385}386 387static size_t btmtkuart_receive_buf(struct serdev_device *serdev,388				    const u8 *data, size_t count)389{390	struct btmtkuart_dev *bdev = serdev_device_get_drvdata(serdev);391 392	btmtkuart_recv(bdev->hdev, data, count);393 394	bdev->hdev->stat.byte_rx += count;395 396	return count;397}398 399static void btmtkuart_write_wakeup(struct serdev_device *serdev)400{401	struct btmtkuart_dev *bdev = serdev_device_get_drvdata(serdev);402 403	btmtkuart_tx_wakeup(bdev);404}405 406static const struct serdev_device_ops btmtkuart_client_ops = {407	.receive_buf = btmtkuart_receive_buf,408	.write_wakeup = btmtkuart_write_wakeup,409};410 411static int btmtkuart_open(struct hci_dev *hdev)412{413	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);414	struct device *dev;415	int err;416 417	err = serdev_device_open(bdev->serdev);418	if (err) {419		bt_dev_err(hdev, "Unable to open UART device %s",420			   dev_name(&bdev->serdev->dev));421		goto err_open;422	}423 424	if (btmtkuart_is_standalone(bdev)) {425		if (bdev->curr_speed != bdev->desired_speed)426			err = serdev_device_set_baudrate(bdev->serdev,427							 115200);428		else429			err = serdev_device_set_baudrate(bdev->serdev,430							 bdev->desired_speed);431 432		if (err < 0) {433			bt_dev_err(hdev, "Unable to set baudrate UART device %s",434				   dev_name(&bdev->serdev->dev));435			goto  err_serdev_close;436		}437 438		serdev_device_set_flow_control(bdev->serdev, false);439	}440 441	bdev->stp_cursor = 2;442	bdev->stp_dlen = 0;443 444	dev = &bdev->serdev->dev;445 446	/* Enable the power domain and clock the device requires */447	pm_runtime_enable(dev);448	err = pm_runtime_resume_and_get(dev);449	if (err < 0)450		goto err_disable_rpm;451 452	err = clk_prepare_enable(bdev->clk);453	if (err < 0)454		goto err_put_rpm;455 456	return 0;457 458err_put_rpm:459	pm_runtime_put_sync(dev);460err_disable_rpm:461	pm_runtime_disable(dev);462err_serdev_close:463	serdev_device_close(bdev->serdev);464err_open:465	return err;466}467 468static int btmtkuart_close(struct hci_dev *hdev)469{470	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);471	struct device *dev = &bdev->serdev->dev;472 473	/* Shutdown the clock and power domain the device requires */474	clk_disable_unprepare(bdev->clk);475	pm_runtime_put_sync(dev);476	pm_runtime_disable(dev);477 478	serdev_device_close(bdev->serdev);479 480	return 0;481}482 483static int btmtkuart_flush(struct hci_dev *hdev)484{485	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);486 487	/* Flush any pending characters */488	serdev_device_write_flush(bdev->serdev);489	skb_queue_purge(&bdev->txq);490 491	cancel_work_sync(&bdev->tx_work);492 493	kfree_skb(bdev->rx_skb);494	bdev->rx_skb = NULL;495 496	bdev->stp_cursor = 2;497	bdev->stp_dlen = 0;498 499	return 0;500}501 502static int btmtkuart_func_query(struct hci_dev *hdev)503{504	struct btmtk_hci_wmt_params wmt_params;505	int status, err;506	u8 param = 0;507 508	/* Query whether the function is enabled */509	wmt_params.op = BTMTK_WMT_FUNC_CTRL;510	wmt_params.flag = 4;511	wmt_params.dlen = sizeof(param);512	wmt_params.data = &param;513	wmt_params.status = &status;514 515	err = mtk_hci_wmt_sync(hdev, &wmt_params);516	if (err < 0) {517		bt_dev_err(hdev, "Failed to query function status (%d)", err);518		return err;519	}520 521	return status;522}523 524static int btmtkuart_change_baudrate(struct hci_dev *hdev)525{526	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);527	struct btmtk_hci_wmt_params wmt_params;528	__le32 baudrate;529	u8 param;530	int err;531 532	/* Indicate the device to enter the probe state the host is533	 * ready to change a new baudrate.534	 */535	baudrate = cpu_to_le32(bdev->desired_speed);536	wmt_params.op = BTMTK_WMT_HIF;537	wmt_params.flag = 1;538	wmt_params.dlen = 4;539	wmt_params.data = &baudrate;540	wmt_params.status = NULL;541 542	err = mtk_hci_wmt_sync(hdev, &wmt_params);543	if (err < 0) {544		bt_dev_err(hdev, "Failed to device baudrate (%d)", err);545		return err;546	}547 548	err = serdev_device_set_baudrate(bdev->serdev,549					 bdev->desired_speed);550	if (err < 0) {551		bt_dev_err(hdev, "Failed to set up host baudrate (%d)",552			   err);553		return err;554	}555 556	serdev_device_set_flow_control(bdev->serdev, false);557 558	/* Send a dummy byte 0xff to activate the new baudrate */559	param = 0xff;560	err = serdev_device_write_buf(bdev->serdev, &param, sizeof(param));561	if (err < 0 || err < sizeof(param))562		return err;563 564	serdev_device_wait_until_sent(bdev->serdev, 0);565 566	/* Wait some time for the device changing baudrate done */567	usleep_range(20000, 22000);568 569	/* Test the new baudrate */570	wmt_params.op = BTMTK_WMT_TEST;571	wmt_params.flag = 7;572	wmt_params.dlen = 0;573	wmt_params.data = NULL;574	wmt_params.status = NULL;575 576	err = mtk_hci_wmt_sync(hdev, &wmt_params);577	if (err < 0) {578		bt_dev_err(hdev, "Failed to test new baudrate (%d)",579			   err);580		return err;581	}582 583	bdev->curr_speed = bdev->desired_speed;584 585	return 0;586}587 588static int btmtkuart_setup(struct hci_dev *hdev)589{590	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);591	struct btmtk_hci_wmt_params wmt_params;592	ktime_t calltime, delta, rettime;593	struct btmtk_tci_sleep tci_sleep;594	unsigned long long duration;595	struct sk_buff *skb;596	int err, status;597	u8 param = 0x1;598 599	calltime = ktime_get();600 601	/* Wakeup MCUSYS is required for certain devices before we start to602	 * do any setups.603	 */604	if (test_bit(BTMTKUART_REQUIRED_WAKEUP, &bdev->tx_state)) {605		wmt_params.op = BTMTK_WMT_WAKEUP;606		wmt_params.flag = 3;607		wmt_params.dlen = 0;608		wmt_params.data = NULL;609		wmt_params.status = NULL;610 611		err = mtk_hci_wmt_sync(hdev, &wmt_params);612		if (err < 0) {613			bt_dev_err(hdev, "Failed to wakeup the chip (%d)", err);614			return err;615		}616 617		clear_bit(BTMTKUART_REQUIRED_WAKEUP, &bdev->tx_state);618	}619 620	if (btmtkuart_is_standalone(bdev))621		btmtkuart_change_baudrate(hdev);622 623	/* Query whether the firmware is already download */624	wmt_params.op = BTMTK_WMT_SEMAPHORE;625	wmt_params.flag = 1;626	wmt_params.dlen = 0;627	wmt_params.data = NULL;628	wmt_params.status = &status;629 630	err = mtk_hci_wmt_sync(hdev, &wmt_params);631	if (err < 0) {632		bt_dev_err(hdev, "Failed to query firmware status (%d)", err);633		return err;634	}635 636	if (status == BTMTK_WMT_PATCH_DONE) {637		bt_dev_info(hdev, "Firmware already downloaded");638		goto ignore_setup_fw;639	}640 641	/* Setup a firmware which the device definitely requires */642	err = btmtk_setup_firmware(hdev, bdev->data->fwname, mtk_hci_wmt_sync);643	if (err < 0)644		return err;645 646ignore_setup_fw:647	/* Query whether the device is already enabled */648	err = readx_poll_timeout(btmtkuart_func_query, hdev, status,649				 status < 0 || status != BTMTK_WMT_ON_PROGRESS,650				 2000, 5000000);651	/* -ETIMEDOUT happens */652	if (err < 0)653		return err;654 655	/* The other errors happen in btusb_mtk_func_query */656	if (status < 0)657		return status;658 659	if (status == BTMTK_WMT_ON_DONE) {660		bt_dev_info(hdev, "function already on");661		goto ignore_func_on;662	}663 664	/* Enable Bluetooth protocol */665	wmt_params.op = BTMTK_WMT_FUNC_CTRL;666	wmt_params.flag = 0;667	wmt_params.dlen = sizeof(param);668	wmt_params.data = &param;669	wmt_params.status = NULL;670 671	err = mtk_hci_wmt_sync(hdev, &wmt_params);672	if (err < 0) {673		bt_dev_err(hdev, "Failed to send wmt func ctrl (%d)", err);674		return err;675	}676 677ignore_func_on:678	/* Apply the low power environment setup */679	tci_sleep.mode = 0x5;680	tci_sleep.duration = cpu_to_le16(0x640);681	tci_sleep.host_duration = cpu_to_le16(0x640);682	tci_sleep.host_wakeup_pin = 0;683	tci_sleep.time_compensation = 0;684 685	skb = __hci_cmd_sync(hdev, 0xfc7a, sizeof(tci_sleep), &tci_sleep,686			     HCI_INIT_TIMEOUT);687	if (IS_ERR(skb)) {688		err = PTR_ERR(skb);689		bt_dev_err(hdev, "Failed to apply low power setting (%d)", err);690		return err;691	}692	kfree_skb(skb);693 694	rettime = ktime_get();695	delta = ktime_sub(rettime, calltime);696	duration = (unsigned long long)ktime_to_ns(delta) >> 10;697 698	bt_dev_info(hdev, "Device setup in %llu usecs", duration);699 700	return 0;701}702 703static int btmtkuart_shutdown(struct hci_dev *hdev)704{705	struct btmtk_hci_wmt_params wmt_params;706	u8 param = 0x0;707	int err;708 709	/* Disable the device */710	wmt_params.op = BTMTK_WMT_FUNC_CTRL;711	wmt_params.flag = 0;712	wmt_params.dlen = sizeof(param);713	wmt_params.data = &param;714	wmt_params.status = NULL;715 716	err = mtk_hci_wmt_sync(hdev, &wmt_params);717	if (err < 0) {718		bt_dev_err(hdev, "Failed to send wmt func ctrl (%d)", err);719		return err;720	}721 722	return 0;723}724 725static int btmtkuart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)726{727	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);728	struct mtk_stp_hdr *shdr;729	int err, dlen, type = 0;730 731	/* Prepend skb with frame type */732	memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);733 734	/* Make sure that there is enough rooms for STP header and trailer */735	if (unlikely(skb_headroom(skb) < sizeof(*shdr)) ||736	    (skb_tailroom(skb) < MTK_STP_TLR_SIZE)) {737		err = pskb_expand_head(skb, sizeof(*shdr), MTK_STP_TLR_SIZE,738				       GFP_ATOMIC);739		if (err < 0)740			return err;741	}742 743	/* Add the STP header */744	dlen = skb->len;745	shdr = skb_push(skb, sizeof(*shdr));746	shdr->prefix = 0x80;747	shdr->dlen = cpu_to_be16((dlen & 0x0fff) | (type << 12));748	shdr->cs = 0;		/* MT7622 doesn't care about checksum value */749 750	/* Add the STP trailer */751	skb_put_zero(skb, MTK_STP_TLR_SIZE);752 753	skb_queue_tail(&bdev->txq, skb);754 755	btmtkuart_tx_wakeup(bdev);756	return 0;757}758 759static int btmtkuart_parse_dt(struct serdev_device *serdev)760{761	struct btmtkuart_dev *bdev = serdev_device_get_drvdata(serdev);762	struct device_node *node = serdev->dev.of_node;763	u32 speed = 921600;764	int err;765 766	if (btmtkuart_is_standalone(bdev)) {767		of_property_read_u32(node, "current-speed", &speed);768 769		bdev->desired_speed = speed;770 771		bdev->vcc = devm_regulator_get(&serdev->dev, "vcc");772		if (IS_ERR(bdev->vcc)) {773			err = PTR_ERR(bdev->vcc);774			return err;775		}776 777		bdev->osc = devm_clk_get_optional(&serdev->dev, "osc");778		if (IS_ERR(bdev->osc)) {779			err = PTR_ERR(bdev->osc);780			return err;781		}782 783		bdev->boot = devm_gpiod_get_optional(&serdev->dev, "boot",784						     GPIOD_OUT_LOW);785		if (IS_ERR(bdev->boot)) {786			err = PTR_ERR(bdev->boot);787			return err;788		}789 790		bdev->pinctrl = devm_pinctrl_get(&serdev->dev);791		if (IS_ERR(bdev->pinctrl)) {792			err = PTR_ERR(bdev->pinctrl);793			return err;794		}795 796		bdev->pins_boot = pinctrl_lookup_state(bdev->pinctrl,797						       "default");798		if (IS_ERR(bdev->pins_boot) && !bdev->boot) {799			err = PTR_ERR(bdev->pins_boot);800			dev_err(&serdev->dev,801				"Should assign RXD to LOW at boot stage\n");802			return err;803		}804 805		bdev->pins_runtime = pinctrl_lookup_state(bdev->pinctrl,806							  "runtime");807		if (IS_ERR(bdev->pins_runtime)) {808			err = PTR_ERR(bdev->pins_runtime);809			return err;810		}811 812		bdev->reset = devm_gpiod_get_optional(&serdev->dev, "reset",813						      GPIOD_OUT_LOW);814		if (IS_ERR(bdev->reset)) {815			err = PTR_ERR(bdev->reset);816			return err;817		}818	} else if (btmtkuart_is_builtin_soc(bdev)) {819		bdev->clk = devm_clk_get(&serdev->dev, "ref");820		if (IS_ERR(bdev->clk))821			return PTR_ERR(bdev->clk);822	}823 824	return 0;825}826 827static int btmtkuart_probe(struct serdev_device *serdev)828{829	struct btmtkuart_dev *bdev;830	struct hci_dev *hdev;831	int err;832 833	bdev = devm_kzalloc(&serdev->dev, sizeof(*bdev), GFP_KERNEL);834	if (!bdev)835		return -ENOMEM;836 837	bdev->data = of_device_get_match_data(&serdev->dev);838	if (!bdev->data)839		return -ENODEV;840 841	bdev->serdev = serdev;842	serdev_device_set_drvdata(serdev, bdev);843 844	serdev_device_set_client_ops(serdev, &btmtkuart_client_ops);845 846	err = btmtkuart_parse_dt(serdev);847	if (err < 0)848		return err;849 850	INIT_WORK(&bdev->tx_work, btmtkuart_tx_work);851	skb_queue_head_init(&bdev->txq);852 853	/* Initialize and register HCI device */854	hdev = hci_alloc_dev();855	if (!hdev) {856		dev_err(&serdev->dev, "Can't allocate HCI device\n");857		return -ENOMEM;858	}859 860	bdev->hdev = hdev;861 862	hdev->bus = HCI_UART;863	hci_set_drvdata(hdev, bdev);864 865	hdev->open     = btmtkuart_open;866	hdev->close    = btmtkuart_close;867	hdev->flush    = btmtkuart_flush;868	hdev->setup    = btmtkuart_setup;869	hdev->shutdown = btmtkuart_shutdown;870	hdev->send     = btmtkuart_send_frame;871	hdev->set_bdaddr = btmtk_set_bdaddr;872	SET_HCIDEV_DEV(hdev, &serdev->dev);873 874	hdev->manufacturer = 70;875	set_bit(HCI_QUIRK_NON_PERSISTENT_SETUP, &hdev->quirks);876 877	if (btmtkuart_is_standalone(bdev)) {878		err = clk_prepare_enable(bdev->osc);879		if (err < 0)880			goto err_hci_free_dev;881 882		if (bdev->boot) {883			gpiod_set_value_cansleep(bdev->boot, 1);884		} else {885			/* Switch to the specific pin state for the booting886			 * requires.887			 */888			pinctrl_select_state(bdev->pinctrl, bdev->pins_boot);889		}890 891		/* Power on */892		err = regulator_enable(bdev->vcc);893		if (err < 0)894			goto err_clk_disable_unprepare;895 896		/* Reset if the reset-gpios is available otherwise the board897		 * -level design should be guaranteed.898		 */899		if (bdev->reset) {900			gpiod_set_value_cansleep(bdev->reset, 1);901			usleep_range(1000, 2000);902			gpiod_set_value_cansleep(bdev->reset, 0);903		}904 905		/* Wait some time until device got ready and switch to the pin906		 * mode the device requires for UART transfers.907		 */908		msleep(50);909 910		if (bdev->boot)911			devm_gpiod_put(&serdev->dev, bdev->boot);912 913		pinctrl_select_state(bdev->pinctrl, bdev->pins_runtime);914 915		/* A standalone device doesn't depends on power domain on SoC,916		 * so mark it as no callbacks.917		 */918		pm_runtime_no_callbacks(&serdev->dev);919 920		set_bit(BTMTKUART_REQUIRED_WAKEUP, &bdev->tx_state);921	}922 923	err = hci_register_dev(hdev);924	if (err < 0) {925		dev_err(&serdev->dev, "Can't register HCI device\n");926		goto err_regulator_disable;927	}928 929	return 0;930 931err_regulator_disable:932	if (btmtkuart_is_standalone(bdev))933		regulator_disable(bdev->vcc);934err_clk_disable_unprepare:935	if (btmtkuart_is_standalone(bdev))936		clk_disable_unprepare(bdev->osc);937err_hci_free_dev:938	hci_free_dev(hdev);939 940	return err;941}942 943static void btmtkuart_remove(struct serdev_device *serdev)944{945	struct btmtkuart_dev *bdev = serdev_device_get_drvdata(serdev);946	struct hci_dev *hdev = bdev->hdev;947 948	if (btmtkuart_is_standalone(bdev)) {949		regulator_disable(bdev->vcc);950		clk_disable_unprepare(bdev->osc);951	}952 953	hci_unregister_dev(hdev);954	hci_free_dev(hdev);955}956 957static const struct btmtkuart_data mt7622_data __maybe_unused = {958	.fwname = FIRMWARE_MT7622,959};960 961static const struct btmtkuart_data mt7663_data __maybe_unused = {962	.flags = BTMTKUART_FLAG_STANDALONE_HW,963	.fwname = FIRMWARE_MT7663,964};965 966static const struct btmtkuart_data mt7668_data __maybe_unused = {967	.flags = BTMTKUART_FLAG_STANDALONE_HW,968	.fwname = FIRMWARE_MT7668,969};970 971#ifdef CONFIG_OF972static const struct of_device_id mtk_of_match_table[] = {973	{ .compatible = "mediatek,mt7622-bluetooth", .data = &mt7622_data},974	{ .compatible = "mediatek,mt7663u-bluetooth", .data = &mt7663_data},975	{ .compatible = "mediatek,mt7668u-bluetooth", .data = &mt7668_data},976	{ }977};978MODULE_DEVICE_TABLE(of, mtk_of_match_table);979#endif980 981static struct serdev_device_driver btmtkuart_driver = {982	.probe = btmtkuart_probe,983	.remove = btmtkuart_remove,984	.driver = {985		.name = "btmtkuart",986		.of_match_table = of_match_ptr(mtk_of_match_table),987	},988};989 990module_serdev_device_driver(btmtkuart_driver);991 992MODULE_AUTHOR("Sean Wang <sean.wang@mediatek.com>");993MODULE_DESCRIPTION("MediaTek Bluetooth Serial driver ver " VERSION);994MODULE_VERSION(VERSION);995MODULE_LICENSE("GPL");996