cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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hci_ll.c (19710B)


      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 *  Texas Instruments' Bluetooth HCILL UART protocol
      4 *
      5 *  HCILL (HCI Low Level) is a Texas Instruments' power management
      6 *  protocol extension to H4.
      7 *
      8 *  Copyright (C) 2007 Texas Instruments, Inc.
      9 *
     10 *  Written by Ohad Ben-Cohen <ohad@bencohen.org>
     11 *
     12 *  Acknowledgements:
     13 *  This file is based on hci_h4.c, which was written
     14 *  by Maxim Krasnyansky and Marcel Holtmann.
     15 */
     16
     17#include <linux/module.h>
     18#include <linux/kernel.h>
     19
     20#include <linux/init.h>
     21#include <linux/sched.h>
     22#include <linux/types.h>
     23#include <linux/fcntl.h>
     24#include <linux/firmware.h>
     25#include <linux/interrupt.h>
     26#include <linux/ptrace.h>
     27#include <linux/poll.h>
     28
     29#include <linux/slab.h>
     30#include <linux/errno.h>
     31#include <linux/string.h>
     32#include <linux/signal.h>
     33#include <linux/ioctl.h>
     34#include <linux/of.h>
     35#include <linux/serdev.h>
     36#include <linux/skbuff.h>
     37#include <linux/ti_wilink_st.h>
     38#include <linux/clk.h>
     39
     40#include <net/bluetooth/bluetooth.h>
     41#include <net/bluetooth/hci_core.h>
     42#include <linux/gpio/consumer.h>
     43#include <linux/nvmem-consumer.h>
     44
     45#include "hci_uart.h"
     46
     47/* Vendor-specific HCI commands */
     48#define HCI_VS_WRITE_BD_ADDR			0xfc06
     49#define HCI_VS_UPDATE_UART_HCI_BAUDRATE		0xff36
     50
     51/* HCILL commands */
     52#define HCILL_GO_TO_SLEEP_IND	0x30
     53#define HCILL_GO_TO_SLEEP_ACK	0x31
     54#define HCILL_WAKE_UP_IND	0x32
     55#define HCILL_WAKE_UP_ACK	0x33
     56
     57/* HCILL states */
     58enum hcill_states_e {
     59	HCILL_ASLEEP,
     60	HCILL_ASLEEP_TO_AWAKE,
     61	HCILL_AWAKE,
     62	HCILL_AWAKE_TO_ASLEEP
     63};
     64
     65struct ll_device {
     66	struct hci_uart hu;
     67	struct serdev_device *serdev;
     68	struct gpio_desc *enable_gpio;
     69	struct clk *ext_clk;
     70	bdaddr_t bdaddr;
     71};
     72
     73struct ll_struct {
     74	struct sk_buff *rx_skb;
     75	struct sk_buff_head txq;
     76	spinlock_t hcill_lock;		/* HCILL state lock	*/
     77	unsigned long hcill_state;	/* HCILL power state	*/
     78	struct sk_buff_head tx_wait_q;	/* HCILL wait queue	*/
     79};
     80
     81/*
     82 * Builds and sends an HCILL command packet.
     83 * These are very simple packets with only 1 cmd byte
     84 */
     85static int send_hcill_cmd(u8 cmd, struct hci_uart *hu)
     86{
     87	int err = 0;
     88	struct sk_buff *skb = NULL;
     89	struct ll_struct *ll = hu->priv;
     90
     91	BT_DBG("hu %p cmd 0x%x", hu, cmd);
     92
     93	/* allocate packet */
     94	skb = bt_skb_alloc(1, GFP_ATOMIC);
     95	if (!skb) {
     96		BT_ERR("cannot allocate memory for HCILL packet");
     97		err = -ENOMEM;
     98		goto out;
     99	}
    100
    101	/* prepare packet */
    102	skb_put_u8(skb, cmd);
    103
    104	/* send packet */
    105	skb_queue_tail(&ll->txq, skb);
    106out:
    107	return err;
    108}
    109
    110/* Initialize protocol */
    111static int ll_open(struct hci_uart *hu)
    112{
    113	struct ll_struct *ll;
    114
    115	BT_DBG("hu %p", hu);
    116
    117	ll = kzalloc(sizeof(*ll), GFP_KERNEL);
    118	if (!ll)
    119		return -ENOMEM;
    120
    121	skb_queue_head_init(&ll->txq);
    122	skb_queue_head_init(&ll->tx_wait_q);
    123	spin_lock_init(&ll->hcill_lock);
    124
    125	ll->hcill_state = HCILL_AWAKE;
    126
    127	hu->priv = ll;
    128
    129	if (hu->serdev) {
    130		struct ll_device *lldev = serdev_device_get_drvdata(hu->serdev);
    131
    132		if (!IS_ERR(lldev->ext_clk))
    133			clk_prepare_enable(lldev->ext_clk);
    134	}
    135
    136	return 0;
    137}
    138
    139/* Flush protocol data */
    140static int ll_flush(struct hci_uart *hu)
    141{
    142	struct ll_struct *ll = hu->priv;
    143
    144	BT_DBG("hu %p", hu);
    145
    146	skb_queue_purge(&ll->tx_wait_q);
    147	skb_queue_purge(&ll->txq);
    148
    149	return 0;
    150}
    151
    152/* Close protocol */
    153static int ll_close(struct hci_uart *hu)
    154{
    155	struct ll_struct *ll = hu->priv;
    156
    157	BT_DBG("hu %p", hu);
    158
    159	skb_queue_purge(&ll->tx_wait_q);
    160	skb_queue_purge(&ll->txq);
    161
    162	kfree_skb(ll->rx_skb);
    163
    164	if (hu->serdev) {
    165		struct ll_device *lldev = serdev_device_get_drvdata(hu->serdev);
    166
    167		gpiod_set_value_cansleep(lldev->enable_gpio, 0);
    168
    169		clk_disable_unprepare(lldev->ext_clk);
    170	}
    171
    172	hu->priv = NULL;
    173
    174	kfree(ll);
    175
    176	return 0;
    177}
    178
    179/*
    180 * internal function, which does common work of the device wake up process:
    181 * 1. places all pending packets (waiting in tx_wait_q list) in txq list.
    182 * 2. changes internal state to HCILL_AWAKE.
    183 * Note: assumes that hcill_lock spinlock is taken,
    184 * shouldn't be called otherwise!
    185 */
    186static void __ll_do_awake(struct ll_struct *ll)
    187{
    188	struct sk_buff *skb = NULL;
    189
    190	while ((skb = skb_dequeue(&ll->tx_wait_q)))
    191		skb_queue_tail(&ll->txq, skb);
    192
    193	ll->hcill_state = HCILL_AWAKE;
    194}
    195
    196/*
    197 * Called upon a wake-up-indication from the device
    198 */
    199static void ll_device_want_to_wakeup(struct hci_uart *hu)
    200{
    201	unsigned long flags;
    202	struct ll_struct *ll = hu->priv;
    203
    204	BT_DBG("hu %p", hu);
    205
    206	/* lock hcill state */
    207	spin_lock_irqsave(&ll->hcill_lock, flags);
    208
    209	switch (ll->hcill_state) {
    210	case HCILL_ASLEEP_TO_AWAKE:
    211		/*
    212		 * This state means that both the host and the BRF chip
    213		 * have simultaneously sent a wake-up-indication packet.
    214		 * Traditionally, in this case, receiving a wake-up-indication
    215		 * was enough and an additional wake-up-ack wasn't needed.
    216		 * This has changed with the BRF6350, which does require an
    217		 * explicit wake-up-ack. Other BRF versions, which do not
    218		 * require an explicit ack here, do accept it, thus it is
    219		 * perfectly safe to always send one.
    220		 */
    221		BT_DBG("dual wake-up-indication");
    222		fallthrough;
    223	case HCILL_ASLEEP:
    224		/* acknowledge device wake up */
    225		if (send_hcill_cmd(HCILL_WAKE_UP_ACK, hu) < 0) {
    226			BT_ERR("cannot acknowledge device wake up");
    227			goto out;
    228		}
    229		break;
    230	default:
    231		/* any other state is illegal */
    232		BT_ERR("received HCILL_WAKE_UP_IND in state %ld",
    233		       ll->hcill_state);
    234		break;
    235	}
    236
    237	/* send pending packets and change state to HCILL_AWAKE */
    238	__ll_do_awake(ll);
    239
    240out:
    241	spin_unlock_irqrestore(&ll->hcill_lock, flags);
    242
    243	/* actually send the packets */
    244	hci_uart_tx_wakeup(hu);
    245}
    246
    247/*
    248 * Called upon a sleep-indication from the device
    249 */
    250static void ll_device_want_to_sleep(struct hci_uart *hu)
    251{
    252	unsigned long flags;
    253	struct ll_struct *ll = hu->priv;
    254
    255	BT_DBG("hu %p", hu);
    256
    257	/* lock hcill state */
    258	spin_lock_irqsave(&ll->hcill_lock, flags);
    259
    260	/* sanity check */
    261	if (ll->hcill_state != HCILL_AWAKE)
    262		BT_ERR("ERR: HCILL_GO_TO_SLEEP_IND in state %ld",
    263		       ll->hcill_state);
    264
    265	/* acknowledge device sleep */
    266	if (send_hcill_cmd(HCILL_GO_TO_SLEEP_ACK, hu) < 0) {
    267		BT_ERR("cannot acknowledge device sleep");
    268		goto out;
    269	}
    270
    271	/* update state */
    272	ll->hcill_state = HCILL_ASLEEP;
    273
    274out:
    275	spin_unlock_irqrestore(&ll->hcill_lock, flags);
    276
    277	/* actually send the sleep ack packet */
    278	hci_uart_tx_wakeup(hu);
    279}
    280
    281/*
    282 * Called upon wake-up-acknowledgement from the device
    283 */
    284static void ll_device_woke_up(struct hci_uart *hu)
    285{
    286	unsigned long flags;
    287	struct ll_struct *ll = hu->priv;
    288
    289	BT_DBG("hu %p", hu);
    290
    291	/* lock hcill state */
    292	spin_lock_irqsave(&ll->hcill_lock, flags);
    293
    294	/* sanity check */
    295	if (ll->hcill_state != HCILL_ASLEEP_TO_AWAKE)
    296		BT_ERR("received HCILL_WAKE_UP_ACK in state %ld",
    297		       ll->hcill_state);
    298
    299	/* send pending packets and change state to HCILL_AWAKE */
    300	__ll_do_awake(ll);
    301
    302	spin_unlock_irqrestore(&ll->hcill_lock, flags);
    303
    304	/* actually send the packets */
    305	hci_uart_tx_wakeup(hu);
    306}
    307
    308/* Enqueue frame for transmittion (padding, crc, etc) */
    309/* may be called from two simultaneous tasklets */
    310static int ll_enqueue(struct hci_uart *hu, struct sk_buff *skb)
    311{
    312	unsigned long flags = 0;
    313	struct ll_struct *ll = hu->priv;
    314
    315	BT_DBG("hu %p skb %p", hu, skb);
    316
    317	/* Prepend skb with frame type */
    318	memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);
    319
    320	/* lock hcill state */
    321	spin_lock_irqsave(&ll->hcill_lock, flags);
    322
    323	/* act according to current state */
    324	switch (ll->hcill_state) {
    325	case HCILL_AWAKE:
    326		BT_DBG("device awake, sending normally");
    327		skb_queue_tail(&ll->txq, skb);
    328		break;
    329	case HCILL_ASLEEP:
    330		BT_DBG("device asleep, waking up and queueing packet");
    331		/* save packet for later */
    332		skb_queue_tail(&ll->tx_wait_q, skb);
    333		/* awake device */
    334		if (send_hcill_cmd(HCILL_WAKE_UP_IND, hu) < 0) {
    335			BT_ERR("cannot wake up device");
    336			break;
    337		}
    338		ll->hcill_state = HCILL_ASLEEP_TO_AWAKE;
    339		break;
    340	case HCILL_ASLEEP_TO_AWAKE:
    341		BT_DBG("device waking up, queueing packet");
    342		/* transient state; just keep packet for later */
    343		skb_queue_tail(&ll->tx_wait_q, skb);
    344		break;
    345	default:
    346		BT_ERR("illegal hcill state: %ld (losing packet)",
    347		       ll->hcill_state);
    348		kfree_skb(skb);
    349		break;
    350	}
    351
    352	spin_unlock_irqrestore(&ll->hcill_lock, flags);
    353
    354	return 0;
    355}
    356
    357static int ll_recv_frame(struct hci_dev *hdev, struct sk_buff *skb)
    358{
    359	struct hci_uart *hu = hci_get_drvdata(hdev);
    360	struct ll_struct *ll = hu->priv;
    361
    362	switch (hci_skb_pkt_type(skb)) {
    363	case HCILL_GO_TO_SLEEP_IND:
    364		BT_DBG("HCILL_GO_TO_SLEEP_IND packet");
    365		ll_device_want_to_sleep(hu);
    366		break;
    367	case HCILL_GO_TO_SLEEP_ACK:
    368		/* shouldn't happen */
    369		bt_dev_err(hdev, "received HCILL_GO_TO_SLEEP_ACK in state %ld",
    370			   ll->hcill_state);
    371		break;
    372	case HCILL_WAKE_UP_IND:
    373		BT_DBG("HCILL_WAKE_UP_IND packet");
    374		ll_device_want_to_wakeup(hu);
    375		break;
    376	case HCILL_WAKE_UP_ACK:
    377		BT_DBG("HCILL_WAKE_UP_ACK packet");
    378		ll_device_woke_up(hu);
    379		break;
    380	}
    381
    382	kfree_skb(skb);
    383	return 0;
    384}
    385
    386#define LL_RECV_SLEEP_IND \
    387	.type = HCILL_GO_TO_SLEEP_IND, \
    388	.hlen = 0, \
    389	.loff = 0, \
    390	.lsize = 0, \
    391	.maxlen = 0
    392
    393#define LL_RECV_SLEEP_ACK \
    394	.type = HCILL_GO_TO_SLEEP_ACK, \
    395	.hlen = 0, \
    396	.loff = 0, \
    397	.lsize = 0, \
    398	.maxlen = 0
    399
    400#define LL_RECV_WAKE_IND \
    401	.type = HCILL_WAKE_UP_IND, \
    402	.hlen = 0, \
    403	.loff = 0, \
    404	.lsize = 0, \
    405	.maxlen = 0
    406
    407#define LL_RECV_WAKE_ACK \
    408	.type = HCILL_WAKE_UP_ACK, \
    409	.hlen = 0, \
    410	.loff = 0, \
    411	.lsize = 0, \
    412	.maxlen = 0
    413
    414static const struct h4_recv_pkt ll_recv_pkts[] = {
    415	{ H4_RECV_ACL,       .recv = hci_recv_frame },
    416	{ H4_RECV_SCO,       .recv = hci_recv_frame },
    417	{ H4_RECV_EVENT,     .recv = hci_recv_frame },
    418	{ LL_RECV_SLEEP_IND, .recv = ll_recv_frame  },
    419	{ LL_RECV_SLEEP_ACK, .recv = ll_recv_frame  },
    420	{ LL_RECV_WAKE_IND,  .recv = ll_recv_frame  },
    421	{ LL_RECV_WAKE_ACK,  .recv = ll_recv_frame  },
    422};
    423
    424/* Recv data */
    425static int ll_recv(struct hci_uart *hu, const void *data, int count)
    426{
    427	struct ll_struct *ll = hu->priv;
    428
    429	if (!test_bit(HCI_UART_REGISTERED, &hu->flags))
    430		return -EUNATCH;
    431
    432	ll->rx_skb = h4_recv_buf(hu->hdev, ll->rx_skb, data, count,
    433				 ll_recv_pkts, ARRAY_SIZE(ll_recv_pkts));
    434	if (IS_ERR(ll->rx_skb)) {
    435		int err = PTR_ERR(ll->rx_skb);
    436		bt_dev_err(hu->hdev, "Frame reassembly failed (%d)", err);
    437		ll->rx_skb = NULL;
    438		return err;
    439	}
    440
    441	return count;
    442}
    443
    444static struct sk_buff *ll_dequeue(struct hci_uart *hu)
    445{
    446	struct ll_struct *ll = hu->priv;
    447
    448	return skb_dequeue(&ll->txq);
    449}
    450
    451#if IS_ENABLED(CONFIG_SERIAL_DEV_BUS)
    452static int read_local_version(struct hci_dev *hdev)
    453{
    454	int err = 0;
    455	unsigned short version = 0;
    456	struct sk_buff *skb;
    457	struct hci_rp_read_local_version *ver;
    458
    459	skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
    460			     HCI_INIT_TIMEOUT);
    461	if (IS_ERR(skb)) {
    462		bt_dev_err(hdev, "Reading TI version information failed (%ld)",
    463			   PTR_ERR(skb));
    464		return PTR_ERR(skb);
    465	}
    466	if (skb->len != sizeof(*ver)) {
    467		err = -EILSEQ;
    468		goto out;
    469	}
    470
    471	ver = (struct hci_rp_read_local_version *)skb->data;
    472	if (le16_to_cpu(ver->manufacturer) != 13) {
    473		err = -ENODEV;
    474		goto out;
    475	}
    476
    477	version = le16_to_cpu(ver->lmp_subver);
    478
    479out:
    480	if (err)
    481		bt_dev_err(hdev, "Failed to read TI version info: %d", err);
    482	kfree_skb(skb);
    483	return err ? err : version;
    484}
    485
    486static int send_command_from_firmware(struct ll_device *lldev,
    487				      struct hci_command *cmd)
    488{
    489	struct sk_buff *skb;
    490
    491	if (cmd->opcode == HCI_VS_UPDATE_UART_HCI_BAUDRATE) {
    492		/* ignore remote change
    493		 * baud rate HCI VS command
    494		 */
    495		bt_dev_warn(lldev->hu.hdev,
    496			    "change remote baud rate command in firmware");
    497		return 0;
    498	}
    499	if (cmd->prefix != 1)
    500		bt_dev_dbg(lldev->hu.hdev, "command type %d", cmd->prefix);
    501
    502	skb = __hci_cmd_sync(lldev->hu.hdev, cmd->opcode, cmd->plen,
    503			     &cmd->speed, HCI_INIT_TIMEOUT);
    504	if (IS_ERR(skb)) {
    505		bt_dev_err(lldev->hu.hdev, "send command failed");
    506		return PTR_ERR(skb);
    507	}
    508	kfree_skb(skb);
    509	return 0;
    510}
    511
    512/*
    513 * download_firmware -
    514 *	internal function which parses through the .bts firmware
    515 *	script file intreprets SEND, DELAY actions only as of now
    516 */
    517static int download_firmware(struct ll_device *lldev)
    518{
    519	unsigned short chip, min_ver, maj_ver;
    520	int version, err, len;
    521	unsigned char *ptr, *action_ptr;
    522	unsigned char bts_scr_name[40];	/* 40 char long bts scr name? */
    523	const struct firmware *fw;
    524	struct hci_command *cmd;
    525
    526	version = read_local_version(lldev->hu.hdev);
    527	if (version < 0)
    528		return version;
    529
    530	chip = (version & 0x7C00) >> 10;
    531	min_ver = (version & 0x007F);
    532	maj_ver = (version & 0x0380) >> 7;
    533	if (version & 0x8000)
    534		maj_ver |= 0x0008;
    535
    536	snprintf(bts_scr_name, sizeof(bts_scr_name),
    537		 "ti-connectivity/TIInit_%d.%d.%d.bts",
    538		 chip, maj_ver, min_ver);
    539
    540	err = request_firmware(&fw, bts_scr_name, &lldev->serdev->dev);
    541	if (err || !fw->data || !fw->size) {
    542		bt_dev_err(lldev->hu.hdev, "request_firmware failed(errno %d) for %s",
    543			   err, bts_scr_name);
    544		return -EINVAL;
    545	}
    546	ptr = (void *)fw->data;
    547	len = fw->size;
    548	/* bts_header to remove out magic number and
    549	 * version
    550	 */
    551	ptr += sizeof(struct bts_header);
    552	len -= sizeof(struct bts_header);
    553
    554	while (len > 0 && ptr) {
    555		bt_dev_dbg(lldev->hu.hdev, " action size %d, type %d ",
    556			   ((struct bts_action *)ptr)->size,
    557			   ((struct bts_action *)ptr)->type);
    558
    559		action_ptr = &(((struct bts_action *)ptr)->data[0]);
    560
    561		switch (((struct bts_action *)ptr)->type) {
    562		case ACTION_SEND_COMMAND:	/* action send */
    563			bt_dev_dbg(lldev->hu.hdev, "S");
    564			cmd = (struct hci_command *)action_ptr;
    565			err = send_command_from_firmware(lldev, cmd);
    566			if (err)
    567				goto out_rel_fw;
    568			break;
    569		case ACTION_WAIT_EVENT:  /* wait */
    570			/* no need to wait as command was synchronous */
    571			bt_dev_dbg(lldev->hu.hdev, "W");
    572			break;
    573		case ACTION_DELAY:	/* sleep */
    574			bt_dev_info(lldev->hu.hdev, "sleep command in scr");
    575			msleep(((struct bts_action_delay *)action_ptr)->msec);
    576			break;
    577		}
    578		len -= (sizeof(struct bts_action) +
    579			((struct bts_action *)ptr)->size);
    580		ptr += sizeof(struct bts_action) +
    581			((struct bts_action *)ptr)->size;
    582	}
    583
    584out_rel_fw:
    585	/* fw download complete */
    586	release_firmware(fw);
    587	return err;
    588}
    589
    590static int ll_set_bdaddr(struct hci_dev *hdev, const bdaddr_t *bdaddr)
    591{
    592	bdaddr_t bdaddr_swapped;
    593	struct sk_buff *skb;
    594
    595	/* HCI_VS_WRITE_BD_ADDR (at least on a CC2560A chip) expects the BD
    596	 * address to be MSB first, but bdaddr_t has the convention of being
    597	 * LSB first.
    598	 */
    599	baswap(&bdaddr_swapped, bdaddr);
    600	skb = __hci_cmd_sync(hdev, HCI_VS_WRITE_BD_ADDR, sizeof(bdaddr_t),
    601			     &bdaddr_swapped, HCI_INIT_TIMEOUT);
    602	if (!IS_ERR(skb))
    603		kfree_skb(skb);
    604
    605	return PTR_ERR_OR_ZERO(skb);
    606}
    607
    608static int ll_setup(struct hci_uart *hu)
    609{
    610	int err, retry = 3;
    611	struct ll_device *lldev;
    612	struct serdev_device *serdev = hu->serdev;
    613	u32 speed;
    614
    615	if (!serdev)
    616		return 0;
    617
    618	lldev = serdev_device_get_drvdata(serdev);
    619
    620	hu->hdev->set_bdaddr = ll_set_bdaddr;
    621
    622	serdev_device_set_flow_control(serdev, true);
    623
    624	do {
    625		/* Reset the Bluetooth device */
    626		gpiod_set_value_cansleep(lldev->enable_gpio, 0);
    627		msleep(5);
    628		gpiod_set_value_cansleep(lldev->enable_gpio, 1);
    629		mdelay(100);
    630		err = serdev_device_wait_for_cts(serdev, true, 200);
    631		if (err) {
    632			bt_dev_err(hu->hdev, "Failed to get CTS");
    633			return err;
    634		}
    635
    636		err = download_firmware(lldev);
    637		if (!err)
    638			break;
    639
    640		/* Toggle BT_EN and retry */
    641		bt_dev_err(hu->hdev, "download firmware failed, retrying...");
    642	} while (retry--);
    643
    644	if (err)
    645		return err;
    646
    647	/* Set BD address if one was specified at probe */
    648	if (!bacmp(&lldev->bdaddr, BDADDR_NONE)) {
    649		/* This means that there was an error getting the BD address
    650		 * during probe, so mark the device as having a bad address.
    651		 */
    652		set_bit(HCI_QUIRK_INVALID_BDADDR, &hu->hdev->quirks);
    653	} else if (bacmp(&lldev->bdaddr, BDADDR_ANY)) {
    654		err = ll_set_bdaddr(hu->hdev, &lldev->bdaddr);
    655		if (err)
    656			set_bit(HCI_QUIRK_INVALID_BDADDR, &hu->hdev->quirks);
    657	}
    658
    659	/* Operational speed if any */
    660	if (hu->oper_speed)
    661		speed = hu->oper_speed;
    662	else if (hu->proto->oper_speed)
    663		speed = hu->proto->oper_speed;
    664	else
    665		speed = 0;
    666
    667	if (speed) {
    668		__le32 speed_le = cpu_to_le32(speed);
    669		struct sk_buff *skb;
    670
    671		skb = __hci_cmd_sync(hu->hdev, HCI_VS_UPDATE_UART_HCI_BAUDRATE,
    672				     sizeof(speed_le), &speed_le,
    673				     HCI_INIT_TIMEOUT);
    674		if (!IS_ERR(skb)) {
    675			kfree_skb(skb);
    676			serdev_device_set_baudrate(serdev, speed);
    677		}
    678	}
    679
    680	return 0;
    681}
    682
    683static const struct hci_uart_proto llp;
    684
    685static int hci_ti_probe(struct serdev_device *serdev)
    686{
    687	struct hci_uart *hu;
    688	struct ll_device *lldev;
    689	struct nvmem_cell *bdaddr_cell;
    690	u32 max_speed = 3000000;
    691
    692	lldev = devm_kzalloc(&serdev->dev, sizeof(struct ll_device), GFP_KERNEL);
    693	if (!lldev)
    694		return -ENOMEM;
    695	hu = &lldev->hu;
    696
    697	serdev_device_set_drvdata(serdev, lldev);
    698	lldev->serdev = hu->serdev = serdev;
    699
    700	lldev->enable_gpio = devm_gpiod_get_optional(&serdev->dev,
    701						     "enable",
    702						     GPIOD_OUT_LOW);
    703	if (IS_ERR(lldev->enable_gpio))
    704		return PTR_ERR(lldev->enable_gpio);
    705
    706	lldev->ext_clk = devm_clk_get(&serdev->dev, "ext_clock");
    707	if (IS_ERR(lldev->ext_clk) && PTR_ERR(lldev->ext_clk) != -ENOENT)
    708		return PTR_ERR(lldev->ext_clk);
    709
    710	of_property_read_u32(serdev->dev.of_node, "max-speed", &max_speed);
    711	hci_uart_set_speeds(hu, 115200, max_speed);
    712
    713	/* optional BD address from nvram */
    714	bdaddr_cell = nvmem_cell_get(&serdev->dev, "bd-address");
    715	if (IS_ERR(bdaddr_cell)) {
    716		int err = PTR_ERR(bdaddr_cell);
    717
    718		if (err == -EPROBE_DEFER)
    719			return err;
    720
    721		/* ENOENT means there is no matching nvmem cell and ENOSYS
    722		 * means that nvmem is not enabled in the kernel configuration.
    723		 */
    724		if (err != -ENOENT && err != -ENOSYS) {
    725			/* If there was some other error, give userspace a
    726			 * chance to fix the problem instead of failing to load
    727			 * the driver. Using BDADDR_NONE as a flag that is
    728			 * tested later in the setup function.
    729			 */
    730			dev_warn(&serdev->dev,
    731				 "Failed to get \"bd-address\" nvmem cell (%d)\n",
    732				 err);
    733			bacpy(&lldev->bdaddr, BDADDR_NONE);
    734		}
    735	} else {
    736		bdaddr_t *bdaddr;
    737		size_t len;
    738
    739		bdaddr = nvmem_cell_read(bdaddr_cell, &len);
    740		nvmem_cell_put(bdaddr_cell);
    741		if (IS_ERR(bdaddr)) {
    742			dev_err(&serdev->dev, "Failed to read nvmem bd-address\n");
    743			return PTR_ERR(bdaddr);
    744		}
    745		if (len != sizeof(bdaddr_t)) {
    746			dev_err(&serdev->dev, "Invalid nvmem bd-address length\n");
    747			kfree(bdaddr);
    748			return -EINVAL;
    749		}
    750
    751		/* As per the device tree bindings, the value from nvmem is
    752		 * expected to be MSB first, but in the kernel it is expected
    753		 * that bdaddr_t is LSB first.
    754		 */
    755		baswap(&lldev->bdaddr, bdaddr);
    756		kfree(bdaddr);
    757	}
    758
    759	return hci_uart_register_device(hu, &llp);
    760}
    761
    762static void hci_ti_remove(struct serdev_device *serdev)
    763{
    764	struct ll_device *lldev = serdev_device_get_drvdata(serdev);
    765
    766	hci_uart_unregister_device(&lldev->hu);
    767}
    768
    769static const struct of_device_id hci_ti_of_match[] = {
    770	{ .compatible = "ti,cc2560" },
    771	{ .compatible = "ti,wl1271-st" },
    772	{ .compatible = "ti,wl1273-st" },
    773	{ .compatible = "ti,wl1281-st" },
    774	{ .compatible = "ti,wl1283-st" },
    775	{ .compatible = "ti,wl1285-st" },
    776	{ .compatible = "ti,wl1801-st" },
    777	{ .compatible = "ti,wl1805-st" },
    778	{ .compatible = "ti,wl1807-st" },
    779	{ .compatible = "ti,wl1831-st" },
    780	{ .compatible = "ti,wl1835-st" },
    781	{ .compatible = "ti,wl1837-st" },
    782	{},
    783};
    784MODULE_DEVICE_TABLE(of, hci_ti_of_match);
    785
    786static struct serdev_device_driver hci_ti_drv = {
    787	.driver		= {
    788		.name	= "hci-ti",
    789		.of_match_table = of_match_ptr(hci_ti_of_match),
    790	},
    791	.probe	= hci_ti_probe,
    792	.remove	= hci_ti_remove,
    793};
    794#else
    795#define ll_setup NULL
    796#endif
    797
    798static const struct hci_uart_proto llp = {
    799	.id		= HCI_UART_LL,
    800	.name		= "LL",
    801	.setup		= ll_setup,
    802	.open		= ll_open,
    803	.close		= ll_close,
    804	.recv		= ll_recv,
    805	.enqueue	= ll_enqueue,
    806	.dequeue	= ll_dequeue,
    807	.flush		= ll_flush,
    808};
    809
    810int __init ll_init(void)
    811{
    812	serdev_device_driver_register(&hci_ti_drv);
    813
    814	return hci_uart_register_proto(&llp);
    815}
    816
    817int __exit ll_deinit(void)
    818{
    819	serdev_device_driver_unregister(&hci_ti_drv);
    820
    821	return hci_uart_unregister_proto(&llp);
    822}