Bluetooth: hci_uart: add serdev driver support library
authorRob Herring <robh@kernel.org>
Tue, 28 Mar 2017 15:59:35 +0000 (17:59 +0200)
committerMarcel Holtmann <marcel@holtmann.org>
Wed, 12 Apr 2017 20:12:17 +0000 (22:12 +0200)
This adds library functions for serdev based BT drivers. This is largely
copied from hci_ldisc.c and modified to use serdev calls. There's a little
bit of duplication, but I avoided intermixing this as the ldisc code should
eventually go away.

Signed-off-by: Rob Herring <robh@kernel.org>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: linux-bluetooth@vger.kernel.org
Acked-by: Pavel Machek <pavel@ucw.cz>
[Fix style issues reported by Pavel]
Signed-off-by: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
drivers/bluetooth/Makefile
drivers/bluetooth/hci_serdev.c [new file with mode: 0644]
drivers/bluetooth/hci_uart.h

index 8062718..fd57168 100644 (file)
@@ -29,6 +29,7 @@ btmrvl-y                      := btmrvl_main.o
 btmrvl-$(CONFIG_DEBUG_FS)      += btmrvl_debugfs.o
 
 hci_uart-y                             := hci_ldisc.o
+hci_uart-$(CONFIG_SERIAL_DEV_BUS)      += hci_serdev.o
 hci_uart-$(CONFIG_BT_HCIUART_H4)       += hci_h4.o
 hci_uart-$(CONFIG_BT_HCIUART_BCSP)     += hci_bcsp.o
 hci_uart-$(CONFIG_BT_HCIUART_LL)       += hci_ll.o
diff --git a/drivers/bluetooth/hci_serdev.c b/drivers/bluetooth/hci_serdev.c
new file mode 100644 (file)
index 0000000..f5ccb2c
--- /dev/null
@@ -0,0 +1,361 @@
+/*
+ *  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>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ */
+
+#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"
+
+struct serdev_device_ops hci_serdev_client_ops;
+
+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)
+               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);
+               }
+       } while(test_bit(HCI_UART_TX_WAKEUP, &hu->tx_state));
+
+       clear_bit(HCI_UART_SENDING, &hu->tx_state);
+}
+
+/* ------- Interface to HCI layer ------ */
+
+/* Initialize device */
+static int hci_uart_open(struct hci_dev *hdev)
+{
+       struct hci_uart *hu  = hci_get_drvdata(hdev);
+
+       BT_DBG("%s %p", hdev->name, hdev);
+
+       serdev_device_set_client_ops(hu->serdev, &hci_serdev_client_ops);
+
+       return serdev_device_open(hu->serdev);
+}
+
+/* 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;
+}
+
+/* Close device */
+static int hci_uart_close(struct hci_dev *hdev)
+{
+       struct hci_uart *hu  = hci_get_drvdata(hdev);
+
+       BT_DBG("hdev %p", hdev);
+
+       hci_uart_flush(hdev);
+       hdev->flush = NULL;
+
+       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_ERR("%s: failed to set baudrate", hdev->name);
+               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_ERR("%s: Reading local version information failed (%ld)",
+                      hdev->name, PTR_ERR(skb));
+               return 0;
+       }
+
+       if (skb->len != sizeof(*ver)) {
+               BT_ERR("%s: Event length mismatch for version information",
+                      hdev->name);
+       }
+
+       kfree_skb(skb);
+       return 0;
+}
+
+/** 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;
+}
+
+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("");
+
+       err = p->open(hu);
+       if (err)
+               return err;
+
+       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->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;
+       SET_HCIDEV_DEV(hdev, &hu->serdev->dev);
+
+       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_RESET_ON_INIT, &hu->hdev_flags))
+               set_bit(HCI_QUIRK_RESET_ON_CLOSE, &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);
+       return err;
+}
index 4aff509..1b41c66 100644 (file)
@@ -58,6 +58,7 @@
 #define HCI_UART_VND_DETECT    5
 
 struct hci_uart;
+struct serdev_device;
 
 struct hci_uart_proto {
        unsigned int id;
@@ -77,6 +78,7 @@ struct hci_uart_proto {
 
 struct hci_uart {
        struct tty_struct       *tty;
+       struct serdev_device    *serdev;
        struct hci_dev          *hdev;
        unsigned long           flags;
        unsigned long           hdev_flags;
@@ -108,6 +110,8 @@ struct hci_uart {
 
 int hci_uart_register_proto(const struct hci_uart_proto *p);
 int hci_uart_unregister_proto(const struct hci_uart_proto *p);
+int hci_uart_register_device(struct hci_uart *hu, const struct hci_uart_proto *p);
+
 int hci_uart_tx_wakeup(struct hci_uart *hu);
 int hci_uart_init_ready(struct hci_uart *hu);
 void hci_uart_init_tty(struct hci_uart *hu);