Bluetooth: hci_uart: Add basic support for Intel Lightning Peak devices

The Intel Lightning Peak devices do not come with Bluetooth firmware
loaded and thus require a full download of the operational Bluetooth
firmware when the device is attached via the Bluetooth line discipline.

Lightning Peak devices start with a bootloader mode that only accepts
a very limited set of HCI commands. The supported commands are enough
to identify the hardware and select the right firmware to load.
Signed-off-by: NLoic Poulain <loic.poulain@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

drivers/bluetooth/Kconfig

@@ -132,6 +132,7 @@ config BT_HCIUART_3WIRE
 config BT_HCIUART_INTEL
 	bool "Intel protocol support"
 	depends on BT_HCIUART
+	select BT_HCIUART_H4
 	select BT_INTEL
 	help
 	  The Intel protocol support enables Bluetooth HCI over serial

drivers/bluetooth/hci_intel.c

@@ -24,8 +24,612 @@
 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/skbuff.h>
+#include <linux/firmware.h>
+#include <linux/wait.h>
 
 #include <net/bluetooth/bluetooth.h>
 #include <net/bluetooth/hci_core.h>
 
 #include "hci_uart.h"
+#include "btintel.h"
+
+#define STATE_BOOTLOADER	0
+#define STATE_DOWNLOADING	1
+#define STATE_FIRMWARE_LOADED	2
+#define STATE_FIRMWARE_FAILED	3
+#define STATE_BOOTING		4
+
+struct intel_data {
+	struct sk_buff *rx_skb;
+	struct sk_buff_head txq;
+	unsigned long flags;
+};
+
+static int intel_open(struct hci_uart *hu)
+{
+	struct intel_data *intel;
+
+	BT_DBG("hu %p", hu);
+
+	intel = kzalloc(sizeof(*intel), GFP_KERNEL);
+	if (!intel)
+		return -ENOMEM;
+
+	skb_queue_head_init(&intel->txq);
+
+	hu->priv = intel;
+	return 0;
+}
+
+static int intel_close(struct hci_uart *hu)
+{
+	struct intel_data *intel = hu->priv;
+
+	BT_DBG("hu %p", hu);
+
+	skb_queue_purge(&intel->txq);
+	kfree_skb(intel->rx_skb);
+	kfree(intel);
+
+	hu->priv = NULL;
+	return 0;
+}
+
+static int intel_flush(struct hci_uart *hu)
+{
+	struct intel_data *intel = hu->priv;
+
+	BT_DBG("hu %p", hu);
+
+	skb_queue_purge(&intel->txq);
+
+	return 0;
+}
+
+static int inject_cmd_complete(struct hci_dev *hdev, __u16 opcode)
+{
+	struct sk_buff *skb;
+	struct hci_event_hdr *hdr;
+	struct hci_ev_cmd_complete *evt;
+
+	skb = bt_skb_alloc(sizeof(*hdr) + sizeof(*evt) + 1, GFP_ATOMIC);
+	if (!skb)
+		return -ENOMEM;
+
+	hdr = (struct hci_event_hdr *)skb_put(skb, sizeof(*hdr));
+	hdr->evt = HCI_EV_CMD_COMPLETE;
+	hdr->plen = sizeof(*evt) + 1;
+
+	evt = (struct hci_ev_cmd_complete *)skb_put(skb, sizeof(*evt));
+	evt->ncmd = 0x01;
+	evt->opcode = cpu_to_le16(opcode);
+
+	*skb_put(skb, 1) = 0x00;
+
+	bt_cb(skb)->pkt_type = HCI_EVENT_PKT;
+
+	return hci_recv_frame(hdev, skb);
+}
+
+static int intel_secure_send(struct hci_dev *hdev, u8 fragment_type,
+			     u32 plen, const void *param)
+{
+	while (plen > 0) {
+		struct sk_buff *skb;
+		u8 cmd_param[253], fragment_len = (plen > 252) ? 252 : plen;
+
+		cmd_param[0] = fragment_type;
+		memcpy(cmd_param + 1, param, fragment_len);
+
+		skb = __hci_cmd_sync(hdev, 0xfc09, fragment_len + 1,
+				     cmd_param, HCI_INIT_TIMEOUT);
+		if (IS_ERR(skb))
+			return PTR_ERR(skb);
+
+		kfree_skb(skb);
+
+		plen -= fragment_len;
+		param += fragment_len;
+	}
+
+	return 0;
+}
+
+static void intel_version_info(struct hci_dev *hdev,
+			       struct intel_version *ver)
+{
+	const char *variant;
+
+	switch (ver->fw_variant) {
+	case 0x06:
+		variant = "Bootloader";
+		break;
+	case 0x23:
+		variant = "Firmware";
+		break;
+	default:
+		return;
+	}
+
+	BT_INFO("%s: %s revision %u.%u build %u week %u %u", hdev->name,
+		variant, ver->fw_revision >> 4, ver->fw_revision & 0x0f,
+		ver->fw_build_num, ver->fw_build_ww, 2000 + ver->fw_build_yy);
+}
+
+static int intel_setup(struct hci_uart *hu)
+{
+	static const u8 reset_param[] = { 0x00, 0x01, 0x00, 0x01,
+					  0x00, 0x08, 0x04, 0x00 };
+	struct intel_data *intel = hu->priv;
+	struct hci_dev *hdev = hu->hdev;
+	struct sk_buff *skb;
+	struct intel_version *ver;
+	struct intel_boot_params *params;
+	const struct firmware *fw;
+	const u8 *fw_ptr;
+	char fwname[64];
+	u32 frag_len;
+	ktime_t calltime, delta, rettime;
+	unsigned long long duration;
+	int err;
+
+	BT_DBG("%s", hdev->name);
+
+	calltime = ktime_get();
+
+	set_bit(STATE_BOOTLOADER, &intel->flags);
+
+	/* Read the Intel version information to determine if the device
+	 * is in bootloader mode or if it already has operational firmware
+	 * loaded.
+	 */
+	skb = __hci_cmd_sync(hdev, 0xfc05, 0, NULL, HCI_INIT_TIMEOUT);
+	if (IS_ERR(skb)) {
+		BT_ERR("%s: Reading Intel version information failed (%ld)",
+		       hdev->name, PTR_ERR(skb));
+		return PTR_ERR(skb);
+	}
+
+	if (skb->len != sizeof(*ver)) {
+		BT_ERR("%s: Intel version event size mismatch", hdev->name);
+		kfree_skb(skb);
+		return -EILSEQ;
+	}
+
+	ver = (struct intel_version *)skb->data;
+	if (ver->status) {
+		BT_ERR("%s: Intel version command failure (%02x)",
+		       hdev->name, ver->status);
+		err = -bt_to_errno(ver->status);
+		kfree_skb(skb);
+		return err;
+	}
+
+	/* The hardware platform number has a fixed value of 0x37 and
+	 * for now only accept this single value.
+	 */
+	if (ver->hw_platform != 0x37) {
+		BT_ERR("%s: Unsupported Intel hardware platform (%u)",
+		       hdev->name, ver->hw_platform);
+		kfree_skb(skb);
+		return -EINVAL;
+	}
+
+	/* At the moment only the hardware variant iBT 3.0 (LnP/SfP) is
+	 * supported by this firmware loading method. This check has been
+	 * put in place to ensure correct forward compatibility options
+	 * when newer hardware variants come along.
+	 */
+	if (ver->hw_variant != 0x0b) {
+		BT_ERR("%s: Unsupported Intel hardware variant (%u)",
+		       hdev->name, ver->hw_variant);
+		kfree_skb(skb);
+		return -EINVAL;
+	}
+
+	intel_version_info(hdev, ver);
+
+	/* The firmware variant determines if the device is in bootloader
+	 * mode or is running operational firmware. The value 0x06 identifies
+	 * the bootloader and the value 0x23 identifies the operational
+	 * firmware.
+	 *
+	 * When the operational firmware is already present, then only
+	 * the check for valid Bluetooth device address is needed. This
+	 * determines if the device will be added as configured or
+	 * unconfigured controller.
+	 *
+	 * It is not possible to use the Secure Boot Parameters in this
+	 * case since that command is only available in bootloader mode.
+	 */
+	if (ver->fw_variant == 0x23) {
+		kfree_skb(skb);
+		clear_bit(STATE_BOOTLOADER, &intel->flags);
+		btintel_check_bdaddr(hdev);
+		return 0;
+	}
+
+	/* If the device is not in bootloader mode, then the only possible
+	 * choice is to return an error and abort the device initialization.
+	 */
+	if (ver->fw_variant != 0x06) {
+		BT_ERR("%s: Unsupported Intel firmware variant (%u)",
+		       hdev->name, ver->fw_variant);
+		kfree_skb(skb);
+		return -ENODEV;
+	}
+
+	kfree_skb(skb);
+
+	/* Read the secure boot parameters to identify the operating
+	 * details of the bootloader.
+	 */
+	skb = __hci_cmd_sync(hdev, 0xfc0d, 0, NULL, HCI_INIT_TIMEOUT);
+	if (IS_ERR(skb)) {
+		BT_ERR("%s: Reading Intel boot parameters failed (%ld)",
+		       hdev->name, PTR_ERR(skb));
+		return PTR_ERR(skb);
+	}
+
+	if (skb->len != sizeof(*params)) {
+		BT_ERR("%s: Intel boot parameters size mismatch", hdev->name);
+		kfree_skb(skb);
+		return -EILSEQ;
+	}
+
+	params = (struct intel_boot_params *)skb->data;
+	if (params->status) {
+		BT_ERR("%s: Intel boot parameters command failure (%02x)",
+		       hdev->name, params->status);
+		err = -bt_to_errno(params->status);
+		kfree_skb(skb);
+		return err;
+	}
+
+	BT_INFO("%s: Device revision is %u", hdev->name,
+		le16_to_cpu(params->dev_revid));
+
+	BT_INFO("%s: Secure boot is %s", hdev->name,
+		params->secure_boot ? "enabled" : "disabled");
+
+	BT_INFO("%s: Minimum firmware build %u week %u %u", hdev->name,
+		params->min_fw_build_nn, params->min_fw_build_cw,
+		2000 + params->min_fw_build_yy);
+
+	/* It is required that every single firmware fragment is acknowledged
+	 * with a command complete event. If the boot parameters indicate
+	 * that this bootloader does not send them, then abort the setup.
+	 */
+	if (params->limited_cce != 0x00) {
+		BT_ERR("%s: Unsupported Intel firmware loading method (%u)",
+		       hdev->name, params->limited_cce);
+		kfree_skb(skb);
+		return -EINVAL;
+	}
+
+	/* If the OTP has no valid Bluetooth device address, then there will
+	 * also be no valid address for the operational firmware.
+	 */
+	if (!bacmp(&params->otp_bdaddr, BDADDR_ANY)) {
+		BT_INFO("%s: No device address configured", hdev->name);
+		set_bit(HCI_QUIRK_INVALID_BDADDR, &hdev->quirks);
+	}
+
+	/* With this Intel bootloader only the hardware variant and device
+	 * revision information are used to select the right firmware.
+	 *
+	 * Currently this bootloader support is limited to hardware variant
+	 * iBT 3.0 (LnP/SfP) which is identified by the value 11 (0x0b).
+	 */
+	snprintf(fwname, sizeof(fwname), "intel/ibt-11-%u.sfi",
+		 le16_to_cpu(params->dev_revid));
+
+	err = request_firmware(&fw, fwname, &hdev->dev);
+	if (err < 0) {
+		BT_ERR("%s: Failed to load Intel firmware file (%d)",
+		       hdev->name, err);
+		kfree_skb(skb);
+		return err;
+	}
+
+	BT_INFO("%s: Found device firmware: %s", hdev->name, fwname);
+
+	kfree_skb(skb);
+
+	if (fw->size < 644) {
+		BT_ERR("%s: Invalid size of firmware file (%zu)",
+		       hdev->name, fw->size);
+		err = -EBADF;
+		goto done;
+	}
+
+	set_bit(STATE_DOWNLOADING, &intel->flags);
+
+	/* Start the firmware download transaction with the Init fragment
+	 * represented by the 128 bytes of CSS header.
+	 */
+	err = intel_secure_send(hdev, 0x00, 128, fw->data);
+	if (err < 0) {
+		BT_ERR("%s: Failed to send firmware header (%d)",
+		       hdev->name, err);
+		goto done;
+	}
+
+	/* Send the 256 bytes of public key information from the firmware
+	 * as the PKey fragment.
+	 */
+	err = intel_secure_send(hdev, 0x03, 256, fw->data + 128);
+	if (err < 0) {
+		BT_ERR("%s: Failed to send firmware public key (%d)",
+		       hdev->name, err);
+		goto done;
+	}
+
+	/* Send the 256 bytes of signature information from the firmware
+	 * as the Sign fragment.
+	 */
+	err = intel_secure_send(hdev, 0x02, 256, fw->data + 388);
+	if (err < 0) {
+		BT_ERR("%s: Failed to send firmware signature (%d)",
+		       hdev->name, err);
+		goto done;
+	}
+
+	fw_ptr = fw->data + 644;
+	frag_len = 0;
+
+	while (fw_ptr - fw->data < fw->size) {
+		struct hci_command_hdr *cmd = (void *)(fw_ptr + frag_len);
+
+		frag_len += sizeof(*cmd) + cmd->plen;
+
+		BT_DBG("%s: patching %td/%zu", hdev->name,
+		       (fw_ptr - fw->data), fw->size);
+
+		/* The parameter length of the secure send command requires
+		 * a 4 byte alignment. It happens so that the firmware file
+		 * contains proper Intel_NOP commands to align the fragments
+		 * as needed.
+		 *
+		 * Send set of commands with 4 byte alignment from the
+		 * firmware data buffer as a single Data fragement.
+		 */
+		if (frag_len % 4)
+			continue;
+
+		/* Send each command from the firmware data buffer as
+		 * a single Data fragment.
+		 */
+		err = intel_secure_send(hdev, 0x01, frag_len, fw_ptr);
+		if (err < 0) {
+			BT_ERR("%s: Failed to send firmware data (%d)",
+			       hdev->name, err);
+			goto done;
+		}
+
+		fw_ptr += frag_len;
+		frag_len = 0;
+	}
+
+	set_bit(STATE_FIRMWARE_LOADED, &intel->flags);
+
+	BT_INFO("%s: Waiting for firmware download to complete", hdev->name);
+
+	/* Before switching the device into operational mode and with that
+	 * booting the loaded firmware, wait for the bootloader notification
+	 * that all fragments have been successfully received.
+	 *
+	 * When the event processing receives the notification, then the
+	 * STATE_DOWNLOADING flag will be cleared.
+	 *
+	 * The firmware loading should not take longer than 5 seconds
+	 * and thus just timeout if that happens and fail the setup
+	 * of this device.
+	 */
+	err = wait_on_bit_timeout(&intel->flags, STATE_DOWNLOADING,
+				  TASK_INTERRUPTIBLE,
+				  msecs_to_jiffies(5000));
+	if (err == 1) {
+		BT_ERR("%s: Firmware loading interrupted", hdev->name);
+		err = -EINTR;
+		goto done;
+	}
+
+	if (err) {
+		BT_ERR("%s: Firmware loading timeout", hdev->name);
+		err = -ETIMEDOUT;
+		goto done;
+	}
+
+	if (test_bit(STATE_FIRMWARE_FAILED, &intel->flags)) {
+		BT_ERR("%s: Firmware loading failed", hdev->name);
+		err = -ENOEXEC;
+		goto done;
+	}
+
+	rettime = ktime_get();
+	delta = ktime_sub(rettime, calltime);
+	duration = (unsigned long long) ktime_to_ns(delta) >> 10;
+
+	BT_INFO("%s: Firmware loaded in %llu usecs", hdev->name, duration);
+
+done:
+	release_firmware(fw);
+
+	if (err < 0)
+		return err;
+
+	calltime = ktime_get();
+
+	set_bit(STATE_BOOTING, &intel->flags);
+
+	skb = __hci_cmd_sync(hdev, 0xfc01, sizeof(reset_param), reset_param,
+			     HCI_INIT_TIMEOUT);
+	if (IS_ERR(skb))
+		return PTR_ERR(skb);
+
+	kfree_skb(skb);
+
+	/* The bootloader will not indicate when the device is ready. This
+	 * is done by the operational firmware sending bootup notification.
+	 *
+	 * Booting into operational firmware should not take longer than
+	 * 1 second. However if that happens, then just fail the setup
+	 * since something went wrong.
+	 */
+	BT_INFO("%s: Waiting for device to boot", hdev->name);
+
+	err = wait_on_bit_timeout(&intel->flags, STATE_BOOTING,
+				  TASK_INTERRUPTIBLE,
+				  msecs_to_jiffies(1000));
+
+	if (err == 1) {
+		BT_ERR("%s: Device boot interrupted", hdev->name);
+		return -EINTR;
+	}
+
+	if (err) {
+		BT_ERR("%s: Device boot timeout", hdev->name);
+		return -ETIMEDOUT;
+	}
+
+	rettime = ktime_get();
+	delta = ktime_sub(rettime, calltime);
+	duration = (unsigned long long) ktime_to_ns(delta) >> 10;
+
+	BT_INFO("%s: Device booted in %llu usecs", hdev->name, duration);
+
+	clear_bit(STATE_BOOTLOADER, &intel->flags);
+
+	return 0;
+}
+
+static int intel_recv_event(struct hci_dev *hdev, struct sk_buff *skb)
+{
+	struct hci_uart *hu = hci_get_drvdata(hdev);
+	struct intel_data *intel = hu->priv;
+	struct hci_event_hdr *hdr;
+
+	if (!test_bit(STATE_BOOTLOADER, &intel->flags))
+		goto recv;
+
+	hdr = (void *)skb->data;
+
+	/* When the firmware loading completes the device sends
+	 * out a vendor specific event indicating the result of
+	 * the firmware loading.
+	 */
+	if (skb->len == 7 && hdr->evt == 0xff && hdr->plen == 0x05 &&
+	    skb->data[2] == 0x06) {
+		if (skb->data[3] != 0x00)
+			set_bit(STATE_FIRMWARE_FAILED, &intel->flags);
+
+		if (test_and_clear_bit(STATE_DOWNLOADING, &intel->flags) &&
+		    test_bit(STATE_FIRMWARE_LOADED, &intel->flags)) {
+			smp_mb__after_atomic();
+			wake_up_bit(&intel->flags, STATE_DOWNLOADING);
+		}
+
+	/* When switching to the operational firmware the device
+	 * sends a vendor specific event indicating that the bootup
+	 * completed.
+	 */
+	} else if (skb->len == 9 && hdr->evt == 0xff && hdr->plen == 0x07 &&
+		   skb->data[2] == 0x02) {
+		if (test_and_clear_bit(STATE_BOOTING, &intel->flags)) {
+			smp_mb__after_atomic();
+			wake_up_bit(&intel->flags, STATE_BOOTING);
+		}
+	}
+recv:
+	return hci_recv_frame(hdev, skb);
+}
+
+static const struct h4_recv_pkt intel_recv_pkts[] = {
+	{ H4_RECV_ACL,   .recv = hci_recv_frame },
+	{ H4_RECV_SCO,   .recv = hci_recv_frame },
+	{ H4_RECV_EVENT, .recv = intel_recv_event },
+};
+
+static int intel_recv(struct hci_uart *hu, const void *data, int count)
+{
+	struct intel_data *intel = hu->priv;
+
+	if (!test_bit(HCI_UART_REGISTERED, &hu->flags))
+		return -EUNATCH;
+
+	intel->rx_skb = h4_recv_buf(hu->hdev, intel->rx_skb, data, count,
+				    intel_recv_pkts,
+				    ARRAY_SIZE(intel_recv_pkts));
+	if (IS_ERR(intel->rx_skb)) {
+		int err = PTR_ERR(intel->rx_skb);
+		BT_ERR("%s: Frame reassembly failed (%d)", hu->hdev->name, err);
+		intel->rx_skb = NULL;
+		return err;
+	}
+
+	return count;
+}
+
+static int intel_enqueue(struct hci_uart *hu, struct sk_buff *skb)
+{
+	struct intel_data *intel = hu->priv;
+
+	BT_DBG("hu %p skb %p", hu, skb);
+
+	skb_queue_tail(&intel->txq, skb);
+
+	return 0;
+}
+
+static struct sk_buff *intel_dequeue(struct hci_uart *hu)
+{
+	struct intel_data *intel = hu->priv;
+	struct sk_buff *skb;
+
+	skb = skb_dequeue(&intel->txq);
+	if (!skb)
+		return skb;
+
+	if (test_bit(STATE_BOOTLOADER, &intel->flags) &&
+	    (bt_cb(skb)->pkt_type == HCI_COMMAND_PKT)) {
+		struct hci_command_hdr *cmd = (void *)skb->data;
+		__u16 opcode = le16_to_cpu(cmd->opcode);
+
+		/* When the 0xfc01 command is issued to boot into
+		 * the operational firmware, it will actually not
+		 * send a command complete event. To keep the flow
+		 * control working inject that event here.
+		 */
+		if (opcode == 0xfc01)
+			inject_cmd_complete(hu->hdev, opcode);
+	}
+
+	/* Prepend skb with frame type */
+	memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
+
+	return skb;
+}
+
+static const struct hci_uart_proto intel_proto = {
+	.id		= HCI_UART_INTEL,
+	.name		= "Intel",
+	.init_speed	= 115200,
+	.open		= intel_open,
+	.close		= intel_close,
+	.flush		= intel_flush,
+	.setup		= intel_setup,
+	.recv		= intel_recv,
+	.enqueue	= intel_enqueue,
+	.dequeue	= intel_dequeue,
+};
+
+int __init intel_init(void)
+{
+	return hci_uart_register_proto(&intel_proto);
+}
+
+int __exit intel_deinit(void)
+{
+	return hci_uart_unregister_proto(&intel_proto);
+}

drivers/bluetooth/hci_ldisc.c

@@ -804,6 +804,9 @@ static int __init hci_uart_init(void)
 #ifdef CONFIG_BT_HCIUART_3WIRE
 	h5_init();
 #endif
+#ifdef CONFIG_BT_HCIUART_INTEL
+	intel_init();
+#endif
 #ifdef CONFIG_BT_HCIUART_BCM
 	bcm_init();
 #endif
@@ -830,6 +833,9 @@ static void __exit hci_uart_exit(void)
 #ifdef CONFIG_BT_HCIUART_3WIRE
 	h5_deinit();
 #endif
+#ifdef CONFIG_BT_HCIUART_INTEL
+	intel_deinit();
+#endif
 #ifdef CONFIG_BT_HCIUART_BCM
 	bcm_deinit();
 #endif

drivers/bluetooth/hci_uart.h

@@ -167,6 +167,11 @@ int h5_init(void);
 int h5_deinit(void);
 #endif
 
+#ifdef CONFIG_BT_HCIUART_INTEL
+int intel_init(void);
+int intel_deinit(void);
+#endif
+
 #ifdef CONFIG_BT_HCIUART_BCM
 int bcm_init(void);
 int bcm_deinit(void);