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);