[PATCH 3/3] bluetooth: hci_ll: Add optional nvmem MAC address source

From: David Lechner
Date: Sun Dec 03 2017 - 22:21:48 EST


This adds an optional nvmem consumer to get a MAC address from an external
source. The MAC address is then set in the Bluetooth chip after the
firmware has been loaded.

This has been tested working with a TI CC2560A chip (in a LEGO MINDSTORMS
EV3).

Signed-off-by: David Lechner <david@xxxxxxxxxxxxxx>
---
drivers/bluetooth/hci_ll.c | 33 +++++++++++++++++++++++++++++++++
1 file changed, 33 insertions(+)

diff --git a/drivers/bluetooth/hci_ll.c b/drivers/bluetooth/hci_ll.c
index 974a788..dd3b5c2 100644
--- a/drivers/bluetooth/hci_ll.c
+++ b/drivers/bluetooth/hci_ll.c
@@ -53,10 +53,12 @@
#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci_core.h>
#include <linux/gpio/consumer.h>
+#include <linux/nvmem-consumer.h>

#include "hci_uart.h"

/* Vendor-specific HCI commands */
+#define HCI_VS_WRITE_BD_ADDR 0xfc06
#define HCI_VS_UPDATE_UART_HCI_BAUDRATE 0xff36

/* HCILL commands */
@@ -89,6 +91,7 @@ struct ll_device {
struct serdev_device *serdev;
struct gpio_desc *enable_gpio;
struct clk *ext_clk;
+ u8 *bdaddr;
};

struct ll_struct {
@@ -698,6 +701,19 @@ static int ll_setup(struct hci_uart *hu)
if (err)
return err;

+ /* Set MAC address, if any */
+ if (lldev->bdaddr) {
+ struct sk_buff *skb;
+
+ skb = __hci_cmd_sync(hu->hdev, HCI_VS_WRITE_BD_ADDR, 6,
+ lldev->bdaddr, HCI_INIT_TIMEOUT);
+ if (IS_ERR(skb))
+ bt_dev_err(hu->hdev, "Failed to set MAC address (%ld)",
+ PTR_ERR(skb));
+ else
+ kfree_skb(skb);
+ }
+
/* Operational speed if any */
if (hu->oper_speed)
speed = hu->oper_speed;
@@ -726,6 +742,7 @@ static int hci_ti_probe(struct serdev_device *serdev)
{
struct hci_uart *hu;
struct ll_device *lldev;
+ struct nvmem_cell *bdaddr_cell;
u32 max_speed = 3000000;

lldev = devm_kzalloc(&serdev->dev, sizeof(struct ll_device), GFP_KERNEL);
@@ -747,6 +764,22 @@ static int hci_ti_probe(struct serdev_device *serdev)
of_property_read_u32(serdev->dev.of_node, "max-speed", &max_speed);
hci_uart_set_speeds(hu, 115200, max_speed);

+ /* optional MAC address from nvram */
+ bdaddr_cell = nvmem_cell_get(&serdev->dev, "mac-address");
+ if (IS_ERR(bdaddr_cell)) {
+ int err = PTR_ERR(bdaddr_cell);
+
+ if (err != -ENOENT) {
+ if (err != -EPROBE_DEFER)
+ dev_err(&serdev->dev,
+ "Failed to get \"mac-address\" nvmem cell\n");
+ return err;
+ }
+ } else {
+ lldev->bdaddr = nvmem_cell_read(bdaddr_cell, NULL);
+ nvmem_cell_put(bdaddr_cell);
+ }
+
return hci_uart_register_device(hu, &llp);
}

--
2.7.4