Bluetooth: hci_bcm: Add serdev support

Add basic support for Broadcom serial slave devices.
Probe the serial device, retrieve its maximum speed and
register a new hci uart device.

Tested/compatible with bcm43438 (RPi3).

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

diff --git a/drivers/bluetooth/Kconfig b/drivers/bluetooth/Kconfig
index 3a6ead6..fae5a74 100644 (file)
--- a/drivers/bluetooth/Kconfig
+++ b/drivers/bluetooth/Kconfig
@@ -168,6 +168,7 @@ config BT_HCIUART_INTEL
 config BT_HCIUART_BCM
        bool "Broadcom protocol support"
        depends on BT_HCIUART
+       depends on BT_HCIUART_SERDEV
        select BT_HCIUART_H4
        select BT_BCM
        help

diff --git a/drivers/bluetooth/hci_bcm.c b/drivers/bluetooth/hci_bcm.c
index 1eb286a..34882f1 100644 (file)
--- a/drivers/bluetooth/hci_bcm.c
+++ b/drivers/bluetooth/hci_bcm.c
@@ -27,6 +27,8 @@
 #include <linux/firmware.h>
 #include <linux/module.h>
 #include <linux/acpi.h>
+#include <linux/of.h>
+#include <linux/property.h>
 #include <linux/platform_device.h>
 #include <linux/clk.h>
 #include <linux/gpio/consumer.h>
@@ -34,6 +36,7 @@
 #include <linux/interrupt.h>
 #include <linux/dmi.h>
 #include <linux/pm_runtime.h>
+#include <linux/serdev.h>
 
 #include <net/bluetooth/bluetooth.h>
 #include <net/bluetooth/hci_core.h>
@@ -46,6 +49,7 @@
 
 #define BCM_AUTOSUSPEND_DELAY  5000 /* default autosleep delay */
 
+/* platform device driver resources */
 struct bcm_device {
        struct list_head        list;
 
@@ -69,6 +73,12 @@ struct bcm_device {
 #endif
 };
 
+/* serdev driver resources */
+struct bcm_serdev {
+       struct hci_uart hu;
+};
+
+/* generic bcm uart resources */
 struct bcm_data {
        struct sk_buff          *rx_skb;
        struct sk_buff_head     txq;
@@ -80,6 +90,14 @@ struct bcm_data {
 static DEFINE_MUTEX(bcm_device_lock);
 static LIST_HEAD(bcm_device_list);
 
+static inline void host_set_baudrate(struct hci_uart *hu, unsigned int speed)
+{
+       if (hu->serdev)
+               serdev_device_set_baudrate(hu->serdev, speed);
+       else
+               hci_uart_set_baudrate(hu, speed);
+}
+
 static int bcm_set_baudrate(struct hci_uart *hu, unsigned int speed)
 {
        struct hci_dev *hdev = hu->hdev;
@@ -290,6 +308,14 @@ static int bcm_open(struct hci_uart *hu)
 
        hu->priv = bcm;
 
+       /* If this is a serdev defined device, then only use
+        * serdev open primitive and skip the rest.
+        */
+       if (hu->serdev) {
+               serdev_device_open(hu->serdev);
+               goto out;
+       }
+
        if (!hu->tty->dev)
                goto out;
 
@@ -325,6 +351,12 @@ static int bcm_close(struct hci_uart *hu)
 
        bt_dev_dbg(hu->hdev, "hu %p", hu);
 
+       /* If this is a serdev defined device, only use serdev
+        * close primitive and then continue as usual.
+        */
+       if (hu->serdev)
+               serdev_device_close(hu->serdev);
+
        /* Protect bcm->dev against removal of the device or driver */
        mutex_lock(&bcm_device_lock);
        if (bcm_device_exists(bdev)) {
@@ -400,7 +432,7 @@ static int bcm_setup(struct hci_uart *hu)
                speed = 0;
 
        if (speed)
-               hci_uart_set_baudrate(hu, speed);
+               host_set_baudrate(hu, speed);
 
        /* Operational speed if any */
        if (hu->oper_speed)
@@ -413,7 +445,7 @@ static int bcm_setup(struct hci_uart *hu)
        if (speed) {
                err = bcm_set_baudrate(hu, speed);
                if (!err)
-                       hci_uart_set_baudrate(hu, speed);
+                       host_set_baudrate(hu, speed);
        }
 
 finalize:
@@ -906,9 +938,57 @@ static struct platform_driver bcm_driver = {
        },
 };
 
+static int bcm_serdev_probe(struct serdev_device *serdev)
+{
+       struct bcm_serdev *bcmdev;
+       u32 speed;
+       int err;
+
+       bcmdev = devm_kzalloc(&serdev->dev, sizeof(*bcmdev), GFP_KERNEL);
+       if (!bcmdev)
+               return -ENOMEM;
+
+       bcmdev->hu.serdev = serdev;
+       serdev_device_set_drvdata(serdev, bcmdev);
+
+       err = device_property_read_u32(&serdev->dev, "max-speed", &speed);
+       if (!err)
+               bcmdev->hu.oper_speed = speed;
+
+       return hci_uart_register_device(&bcmdev->hu, &bcm_proto);
+}
+
+static void bcm_serdev_remove(struct serdev_device *serdev)
+{
+       struct bcm_serdev *bcmdev = serdev_device_get_drvdata(serdev);
+
+       hci_uart_unregister_device(&bcmdev->hu);
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id bcm_bluetooth_of_match[] = {
+       { .compatible = "brcm,bcm43438-bt" },
+       { },
+};
+MODULE_DEVICE_TABLE(of, bcm_bluetooth_of_match);
+#endif
+
+static struct serdev_device_driver bcm_serdev_driver = {
+       .probe = bcm_serdev_probe,
+       .remove = bcm_serdev_remove,
+       .driver = {
+               .name = "hci_uart_bcm",
+               .of_match_table = of_match_ptr(bcm_bluetooth_of_match),
+       },
+};
+
 int __init bcm_init(void)
 {
+       /* For now, we need to keep both platform device
+        * driver (ACPI generated) and serdev driver (DT).
+        */
        platform_driver_register(&bcm_driver);
+       serdev_device_driver_register(&bcm_serdev_driver);
 
        return hci_uart_register_proto(&bcm_proto);
 }
@@ -916,6 +996,7 @@ int __init bcm_init(void)
 int __exit bcm_deinit(void)
 {
        platform_driver_unregister(&bcm_driver);
+       serdev_device_driver_unregister(&bcm_serdev_driver);
 
        return hci_uart_unregister_proto(&bcm_proto);
 }