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Diffstat (limited to 'drivers/bluetooth/hci_serdev.c')
-rw-r--r--drivers/bluetooth/hci_serdev.c418
1 files changed, 418 insertions, 0 deletions
diff --git a/drivers/bluetooth/hci_serdev.c b/drivers/bluetooth/hci_serdev.c
new file mode 100644
index 000000000..f16fd79bc
--- /dev/null
+++ b/drivers/bluetooth/hci_serdev.c
@@ -0,0 +1,418 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Bluetooth HCI serdev driver lib
+ *
+ * Copyright (C) 2017 Linaro, Ltd., Rob Herring <robh@kernel.org>
+ *
+ * Based on hci_ldisc.c:
+ *
+ * Copyright (C) 2000-2001 Qualcomm Incorporated
+ * Copyright (C) 2002-2003 Maxim Krasnyansky <maxk@qualcomm.com>
+ * Copyright (C) 2004-2005 Marcel Holtmann <marcel@holtmann.org>
+ */
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/serdev.h>
+#include <linux/skbuff.h>
+
+#include <net/bluetooth/bluetooth.h>
+#include <net/bluetooth/hci_core.h>
+
+#include "hci_uart.h"
+
+static inline void hci_uart_tx_complete(struct hci_uart *hu, int pkt_type)
+{
+ struct hci_dev *hdev = hu->hdev;
+
+ /* Update HCI stat counters */
+ switch (pkt_type) {
+ case HCI_COMMAND_PKT:
+ hdev->stat.cmd_tx++;
+ break;
+
+ case HCI_ACLDATA_PKT:
+ hdev->stat.acl_tx++;
+ break;
+
+ case HCI_SCODATA_PKT:
+ hdev->stat.sco_tx++;
+ break;
+ }
+}
+
+static inline struct sk_buff *hci_uart_dequeue(struct hci_uart *hu)
+{
+ struct sk_buff *skb = hu->tx_skb;
+
+ if (!skb) {
+ if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
+ skb = hu->proto->dequeue(hu);
+ } else
+ hu->tx_skb = NULL;
+
+ return skb;
+}
+
+static void hci_uart_write_work(struct work_struct *work)
+{
+ struct hci_uart *hu = container_of(work, struct hci_uart, write_work);
+ struct serdev_device *serdev = hu->serdev;
+ struct hci_dev *hdev = hu->hdev;
+ struct sk_buff *skb;
+
+ /* REVISIT:
+ * should we cope with bad skbs or ->write() returning an error value?
+ */
+ do {
+ clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state);
+
+ while ((skb = hci_uart_dequeue(hu))) {
+ int len;
+
+ len = serdev_device_write_buf(serdev,
+ skb->data, skb->len);
+ hdev->stat.byte_tx += len;
+
+ skb_pull(skb, len);
+ if (skb->len) {
+ hu->tx_skb = skb;
+ break;
+ }
+
+ hci_uart_tx_complete(hu, hci_skb_pkt_type(skb));
+ kfree_skb(skb);
+ }
+
+ clear_bit(HCI_UART_SENDING, &hu->tx_state);
+ } while (test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state));
+}
+
+/* ------- Interface to HCI layer ------ */
+
+/* Reset device */
+static int hci_uart_flush(struct hci_dev *hdev)
+{
+ struct hci_uart *hu = hci_get_drvdata(hdev);
+
+ BT_DBG("hdev %p serdev %p", hdev, hu->serdev);
+
+ if (hu->tx_skb) {
+ kfree_skb(hu->tx_skb); hu->tx_skb = NULL;
+ }
+
+ /* Flush any pending characters in the driver and discipline. */
+ serdev_device_write_flush(hu->serdev);
+
+ if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
+ hu->proto->flush(hu);
+
+ return 0;
+}
+
+/* Initialize device */
+static int hci_uart_open(struct hci_dev *hdev)
+{
+ struct hci_uart *hu = hci_get_drvdata(hdev);
+ int err;
+
+ BT_DBG("%s %p", hdev->name, hdev);
+
+ /* When Quirk HCI_QUIRK_NON_PERSISTENT_SETUP is set by
+ * driver, BT SoC is completely turned OFF during
+ * BT OFF. Upon next BT ON UART port should be opened.
+ */
+ if (!test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
+ err = serdev_device_open(hu->serdev);
+ if (err)
+ return err;
+ set_bit(HCI_UART_PROTO_READY, &hu->flags);
+ }
+
+ /* Undo clearing this from hci_uart_close() */
+ hdev->flush = hci_uart_flush;
+
+ return 0;
+}
+
+/* Close device */
+static int hci_uart_close(struct hci_dev *hdev)
+{
+ struct hci_uart *hu = hci_get_drvdata(hdev);
+
+ BT_DBG("hdev %p", hdev);
+
+ if (!test_bit(HCI_UART_PROTO_READY, &hu->flags))
+ return 0;
+
+ hci_uart_flush(hdev);
+ hdev->flush = NULL;
+
+ /* When QUIRK HCI_QUIRK_NON_PERSISTENT_SETUP is set by driver,
+ * BT SOC is completely powered OFF during BT OFF, holding port
+ * open may drain the battery.
+ */
+ if (test_bit(HCI_QUIRK_NON_PERSISTENT_SETUP, &hdev->quirks)) {
+ clear_bit(HCI_UART_PROTO_READY, &hu->flags);
+ serdev_device_close(hu->serdev);
+ }
+
+ return 0;
+}
+
+/* Send frames from HCI layer */
+static int hci_uart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
+{
+ struct hci_uart *hu = hci_get_drvdata(hdev);
+
+ BT_DBG("%s: type %d len %d", hdev->name, hci_skb_pkt_type(skb),
+ skb->len);
+
+ hu->proto->enqueue(hu, skb);
+
+ hci_uart_tx_wakeup(hu);
+
+ return 0;
+}
+
+static int hci_uart_setup(struct hci_dev *hdev)
+{
+ struct hci_uart *hu = hci_get_drvdata(hdev);
+ struct hci_rp_read_local_version *ver;
+ struct sk_buff *skb;
+ unsigned int speed;
+ int err;
+
+ /* Init speed if any */
+ if (hu->init_speed)
+ speed = hu->init_speed;
+ else if (hu->proto->init_speed)
+ speed = hu->proto->init_speed;
+ else
+ speed = 0;
+
+ if (speed)
+ serdev_device_set_baudrate(hu->serdev, speed);
+
+ /* Operational speed if any */
+ if (hu->oper_speed)
+ speed = hu->oper_speed;
+ else if (hu->proto->oper_speed)
+ speed = hu->proto->oper_speed;
+ else
+ speed = 0;
+
+ if (hu->proto->set_baudrate && speed) {
+ err = hu->proto->set_baudrate(hu, speed);
+ if (err)
+ bt_dev_err(hdev, "Failed to set baudrate");
+ else
+ serdev_device_set_baudrate(hu->serdev, speed);
+ }
+
+ if (hu->proto->setup)
+ return hu->proto->setup(hu);
+
+ if (!test_bit(HCI_UART_VND_DETECT, &hu->hdev_flags))
+ return 0;
+
+ skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
+ HCI_INIT_TIMEOUT);
+ if (IS_ERR(skb)) {
+ bt_dev_err(hdev, "Reading local version info failed (%ld)",
+ PTR_ERR(skb));
+ return 0;
+ }
+
+ if (skb->len != sizeof(*ver))
+ bt_dev_err(hdev, "Event length mismatch for version info");
+
+ kfree_skb(skb);
+ return 0;
+}
+
+/* Check if the device is wakeable */
+static bool hci_uart_wakeup(struct hci_dev *hdev)
+{
+ /* HCI UART devices are assumed to be wakeable by default.
+ * Implement wakeup callback to override this behavior.
+ */
+ return true;
+}
+
+/** hci_uart_write_wakeup - transmit buffer wakeup
+ * @serdev: serial device
+ *
+ * This function is called by the serdev framework when it accepts
+ * more data being sent.
+ */
+static void hci_uart_write_wakeup(struct serdev_device *serdev)
+{
+ struct hci_uart *hu = serdev_device_get_drvdata(serdev);
+
+ BT_DBG("");
+
+ if (!hu || serdev != hu->serdev) {
+ WARN_ON(1);
+ return;
+ }
+
+ if (test_bit(HCI_UART_PROTO_READY, &hu->flags))
+ hci_uart_tx_wakeup(hu);
+}
+
+/** hci_uart_receive_buf - receive buffer wakeup
+ * @serdev: serial device
+ * @data: pointer to received data
+ * @count: count of received data in bytes
+ *
+ * This function is called by the serdev framework when it received data
+ * in the RX buffer.
+ *
+ * Return: number of processed bytes
+ */
+static int hci_uart_receive_buf(struct serdev_device *serdev, const u8 *data,
+ size_t count)
+{
+ struct hci_uart *hu = serdev_device_get_drvdata(serdev);
+
+ if (!hu || serdev != hu->serdev) {
+ WARN_ON(1);
+ return 0;
+ }
+
+ if (!test_bit(HCI_UART_PROTO_READY, &hu->flags))
+ return 0;
+
+ /* It does not need a lock here as it is already protected by a mutex in
+ * tty caller
+ */
+ hu->proto->recv(hu, data, count);
+
+ if (hu->hdev)
+ hu->hdev->stat.byte_rx += count;
+
+ return count;
+}
+
+static const struct serdev_device_ops hci_serdev_client_ops = {
+ .receive_buf = hci_uart_receive_buf,
+ .write_wakeup = hci_uart_write_wakeup,
+};
+
+int hci_uart_register_device(struct hci_uart *hu,
+ const struct hci_uart_proto *p)
+{
+ int err;
+ struct hci_dev *hdev;
+
+ BT_DBG("");
+
+ serdev_device_set_client_ops(hu->serdev, &hci_serdev_client_ops);
+
+ if (percpu_init_rwsem(&hu->proto_lock))
+ return -ENOMEM;
+
+ err = serdev_device_open(hu->serdev);
+ if (err)
+ goto err_rwsem;
+
+ err = p->open(hu);
+ if (err)
+ goto err_open;
+
+ hu->proto = p;
+ set_bit(HCI_UART_PROTO_READY, &hu->flags);
+
+ /* Initialize and register HCI device */
+ hdev = hci_alloc_dev();
+ if (!hdev) {
+ BT_ERR("Can't allocate HCI device");
+ err = -ENOMEM;
+ goto err_alloc;
+ }
+
+ hu->hdev = hdev;
+
+ hdev->bus = HCI_UART;
+ hci_set_drvdata(hdev, hu);
+
+ INIT_WORK(&hu->init_ready, hci_uart_init_work);
+ INIT_WORK(&hu->write_work, hci_uart_write_work);
+
+ /* Only when vendor specific setup callback is provided, consider
+ * the manufacturer information valid. This avoids filling in the
+ * value for Ericsson when nothing is specified.
+ */
+ if (hu->proto->setup)
+ hdev->manufacturer = hu->proto->manufacturer;
+
+ hdev->open = hci_uart_open;
+ hdev->close = hci_uart_close;
+ hdev->flush = hci_uart_flush;
+ hdev->send = hci_uart_send_frame;
+ hdev->setup = hci_uart_setup;
+ if (!hdev->wakeup)
+ hdev->wakeup = hci_uart_wakeup;
+ SET_HCIDEV_DEV(hdev, &hu->serdev->dev);
+
+ if (test_bit(HCI_UART_NO_SUSPEND_NOTIFIER, &hu->flags))
+ set_bit(HCI_QUIRK_NO_SUSPEND_NOTIFIER, &hdev->quirks);
+
+ if (test_bit(HCI_UART_RAW_DEVICE, &hu->hdev_flags))
+ set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
+
+ if (test_bit(HCI_UART_EXT_CONFIG, &hu->hdev_flags))
+ set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
+
+ if (test_bit(HCI_UART_CREATE_AMP, &hu->hdev_flags))
+ hdev->dev_type = HCI_AMP;
+ else
+ hdev->dev_type = HCI_PRIMARY;
+
+ if (test_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags))
+ return 0;
+
+ if (hci_register_dev(hdev) < 0) {
+ BT_ERR("Can't register HCI device");
+ err = -ENODEV;
+ goto err_register;
+ }
+
+ set_bit(HCI_UART_REGISTERED, &hu->flags);
+
+ return 0;
+
+err_register:
+ hci_free_dev(hdev);
+err_alloc:
+ clear_bit(HCI_UART_PROTO_READY, &hu->flags);
+ p->close(hu);
+err_open:
+ serdev_device_close(hu->serdev);
+err_rwsem:
+ percpu_free_rwsem(&hu->proto_lock);
+ return err;
+}
+EXPORT_SYMBOL_GPL(hci_uart_register_device);
+
+void hci_uart_unregister_device(struct hci_uart *hu)
+{
+ struct hci_dev *hdev = hu->hdev;
+
+ cancel_work_sync(&hu->init_ready);
+ if (test_bit(HCI_UART_REGISTERED, &hu->flags))
+ hci_unregister_dev(hdev);
+ hci_free_dev(hdev);
+
+ cancel_work_sync(&hu->write_work);
+
+ hu->proto->close(hu);
+
+ if (test_bit(HCI_UART_PROTO_READY, &hu->flags)) {
+ clear_bit(HCI_UART_PROTO_READY, &hu->flags);
+ serdev_device_close(hu->serdev);
+ }
+ percpu_free_rwsem(&hu->proto_lock);
+}
+EXPORT_SYMBOL_GPL(hci_uart_unregister_device);