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: Loic Poulain <loic.poulain@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

4 files changed, 616 insertions, 0 deletions

diff --git a/drivers/bluetooth/Kconfig b/drivers/bluetooth/Kconfig
index 2e777071e1dc..79e8234b1aa5 100644
--- a/drivers/bluetooth/Kconfig
+++ b/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
diff --git a/drivers/bluetooth/hci_intel.c b/drivers/bluetooth/hci_intel.c
index 5dd07bf05236..ade19aaeb5c5 100644
--- a/drivers/bluetooth/hci_intel.c
+++ b/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);
+}
diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c
index 177dd69fdd95..051f8213697d 100644
--- a/drivers/bluetooth/hci_ldisc.c
+++ b/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
diff --git a/drivers/bluetooth/hci_uart.h b/drivers/bluetooth/hci_uart.h
index ce9c670956f5..496587a73a9d 100644
--- a/drivers/bluetooth/hci_uart.h
+++ b/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);