[PATCH 1/2] device property: Add device_get_bd_address() and fwnode_get_bd_address()

From: Matthias Kaehlcke
Date: Thu Sep 20 2018 - 18:34:59 EST


Provide an API for Bluetooth drivers to retrieve the Bluetooth Device
address (BD_ADDR) for a device. If the device node has a property
'local-bd-address' the BD address is read from this property.

Signed-off-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
---
drivers/base/property.c | 49 ++++++++++++++++++++++++++++++++++++++++
include/linux/property.h | 4 ++++
2 files changed, 53 insertions(+)

diff --git a/drivers/base/property.c b/drivers/base/property.c
index 240ab5230ff6..8fe546b9805a 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -18,6 +18,8 @@
#include <linux/etherdevice.h>
#include <linux/phy.h>

+#define BD_ADDR_LEN 6
+
struct property_set {
struct device *dev;
struct fwnode_handle fwnode;
@@ -1315,6 +1317,53 @@ void *device_get_mac_address(struct device *dev, char *addr, int alen)
}
EXPORT_SYMBOL(device_get_mac_address);

+/**
+ * fwnode_get_bd_address - Get the Bluetooth Device Address (BD_ADDR) from the
+ * firmware node
+ * @fwnode: Pointer to the firmware node
+ * @addr: Address of buffer to store the BD address in
+ * @alen: Length of the buffer pointed to by addr, should be BD_ADDR_LEN
+ *
+ * Search the firmware node for 'local-bd-address'.
+ *
+ * All-zero BD addresses are rejected, because those could be properties
+ * that exist in the firmware tables, but were not updated by the firmware. For
+ * example, the DTS could define 'local-bd-address', with zero BD addresses.
+ */
+int fwnode_get_bd_address(struct fwnode_handle *fwnode, u8 *addr, int alen)
+{
+ u8 buf[BD_ADDR_LEN];
+ int ret;
+
+ if (alen != BD_ADDR_LEN)
+ return -EINVAL;
+
+ ret = fwnode_property_read_u8_array(fwnode, "local-bd-address",
+ buf, alen);
+ if (ret < 0)
+ return ret;
+ if (is_zero_ether_addr(buf))
+ return -ENODATA;
+
+ memcpy(addr, buf, BD_ADDR_LEN);
+
+ return 0;
+}
+EXPORT_SYMBOL(fwnode_get_bd_address);
+
+/**
+ * device_get_bd_address - Get the Bluetooth Device Address (BD_ADDR) for a
+ * given device
+ * @dev: Pointer to the device
+ * @addr: Address of buffer to store the BD address in
+ * @alen: Length of the buffer pointed to by addr, should be BD_ADDR_LEN
+ */
+int device_get_bd_address(struct device *dev, u8 *addr, int alen)
+{
+ return fwnode_get_bd_address(dev_fwnode(dev), addr, alen);
+}
+EXPORT_SYMBOL(device_get_bd_address);
+
/**
* fwnode_irq_get - Get IRQ directly from a fwnode
* @fwnode: Pointer to the firmware node
diff --git a/include/linux/property.h b/include/linux/property.h
index ac8a1ebc4c1b..4e2f1b276f4f 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -287,9 +287,13 @@ int device_get_phy_mode(struct device *dev);

void *device_get_mac_address(struct device *dev, char *addr, int alen);

+int device_get_bd_address(struct device *dev, u8 *addr, int alen);
+
int fwnode_get_phy_mode(struct fwnode_handle *fwnode);
void *fwnode_get_mac_address(struct fwnode_handle *fwnode,
char *addr, int alen);
+int fwnode_get_bd_address(struct fwnode_handle *fwnode,
+ u8 *addr, int alen);
struct fwnode_handle *fwnode_graph_get_next_endpoint(
const struct fwnode_handle *fwnode, struct fwnode_handle *prev);
struct fwnode_handle *
--
2.19.0.444.g18242da7ef-goog