[PATCH v3 0/3] Bluetooth: hci_ll: Get BD address from NVMEM

[PATCH v3 0/3] Bluetooth: hci_ll: Get BD address from NVMEM

[David Lechner]

This series adds supporting getting the BD address from a NVMEM provider
for "LL" HCI controllers (Texas Instruments).

v3 changes:
* Additional comments on why swapping bytes is needed.
* Fixed comment style and trailing whitespace.
* Rework error handling for nvmem cell code.

v2 changes:
* Fixed typos in dt-bindings
* Use "bd-address" instead of "mac-address"
* Updated dt-bindings to specify the byte order of "bd-address"
* New patch "Bluetooth: hci_ll: add support for setting public address"
* Dropped patch "Bluetooth: hci_ll: add constant for vendor-specific command"
  that is already in bluetooth-next
* Rework error handling
* Use bdaddr_t, bacmp and other bluetooth utils

David Lechner (3):
  Bluetooth: hci_ll: add support for setting public address
  dt-bindings: Add optional nvmem BD address bindings to ti,wlink-st
  Bluetooth: hci_ll: Add optional nvmem BD address source

 .../devicetree/bindings/net/ti,wilink-st.txt       |  5 ++
 drivers/bluetooth/hci_ll.c                         | 77 ++++++++++++++++++++++
 2 files changed, 82 insertions(+)

-- 
2.7.4

[PATCH v3 1/3] Bluetooth: hci_ll: add support for setting public address

[David Lechner]

This adds support for setting the public address on Texas Instruments
Bluetooth chips using a vendor-specific command.

This has been tested on a CC2560A chip. The TI wiki also indicates that
this command should work on TI WL17xx/WL18xx Bluetooth chips.

During review, there was some question as to the correctness of the byte
swapping since TI's documentation is not clear on this matter. This can
be tested with the btmgmt utility from bluez. The adapter must be powered
off to change the address. If the baswap() is omitted, address is reversed.

In case there is a issue in the future, here is the output of btmon during
the command `btmgmt public-addr 00:11:22:33:44:55`:

Bluetooth monitor ver 5.43
= Note: Linux version 4.15.0-rc2-08561-gcb132a1-dirty (armv5tejl)      0.707043
= Note: Bluetooth subsystem version 2.22                               0.707091
= New Index: 00:17:E7:BD:1C:8E (Primary,UART,hci0)              [hci0] 0.707106
@ MGMT Open: btmgmt (privileged) version 1.14                 {0x0002} 0.707124
@ MGMT Open: bluetoothd (privileged) version 1.14             {0x0001} 0.707137
@ MGMT Open: btmon (privileged) version 1.14                  {0x0003} 0.707540
@ MGMT Command: Set Public Address (0x0039) plen 6    {0x0002} [hci0] 11.167991
        Address: 00:11:22:33:44:55 (CIMSYS Inc)
@ MGMT Event: Command Complete (0x0001) plen 7        {0x0002} [hci0] 11.175681
      Set Public Address (0x0039) plen 4
        Status: Success (0x00)
        Missing options: 0x00000000
@ MGMT Event: Index Removed (0x0005) plen 0           {0x0003} [hci0] 11.175757
@ MGMT Event: Index Removed (0x0005) plen 0           {0x0002} [hci0] 11.175757
@ MGMT Event: Index Removed (0x0005) plen 0           {0x0001} [hci0] 11.175757
= Open Index: 00:17:E7:BD:1C:8E                                [hci0] 11.176807
< HCI Command: Vendor (0x3f|0x0006) plen 6                     [hci0] 11.176975
        00 11 22 33 44 55                                .."3DU
> HCI Event: Command Complete (0x0e) plen 4                    [hci0] 11.188260
      Vendor (0x3f|0x0006) ncmd 1
        Status: Success (0x00)
...
< HCI Command: Read Local Version Info.. (0x04|0x0001) plen 0  [hci0] 11.189859
> HCI Event: Command Complete (0x0e) plen 12                   [hci0] 11.190732
      Read Local Version Information (0x04|0x0001) ncmd 1
        Status: Success (0x00)
        HCI version: Bluetooth 2.1 (0x04) - Revision 0 (0x0000)
        LMP version: Bluetooth 2.1 (0x04) - Subversion 6431 (0x191f)
        Manufacturer: Texas Instruments Inc. (13)
< HCI Command: Read BD ADDR (0x04|0x0009) plen 0               [hci0] 11.191027
> HCI Event: Command Complete (0x0e) plen 10                   [hci0] 11.192101
      Read BD ADDR (0x04|0x0009) ncmd 1
        Status: Success (0x00)
        Address: 00:11:22:33:44:55 (CIMSYS Inc)
...

Signed-off-by: David Lechner <david@lechnology.com>
---
 drivers/bluetooth/hci_ll.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/drivers/bluetooth/hci_ll.c b/drivers/bluetooth/hci_ll.c
index efcfbe9..c948e8d 100644
--- a/drivers/bluetooth/hci_ll.c
+++ b/drivers/bluetooth/hci_ll.c
@@ -57,6 +57,7 @@
 #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 */
@@ -662,6 +663,24 @@ static int download_firmware(struct ll_device *lldev)
 	return err;
 }
 
+static int ll_set_bdaddr(struct hci_dev *hdev, const bdaddr_t *bdaddr)
+{
+	bdaddr_t bdaddr_swapped;
+	struct sk_buff *skb;
+
+	/* HCI_VS_WRITE_BD_ADDR (at least on a CC2560A chip) expects the BD
+	 * address to be MSB first, but bdaddr_t has the convention of being
+	 * LSB first.
+	 */
+	baswap(&bdaddr_swapped, bdaddr);
+	skb = __hci_cmd_sync(hdev, HCI_VS_WRITE_BD_ADDR, sizeof(bdaddr_t),
+			     &bdaddr_swapped, HCI_INIT_TIMEOUT);
+	if (!IS_ERR(skb))
+		kfree_skb(skb);
+
+	return PTR_ERR_OR_ZERO(skb);
+}
+
 static int ll_setup(struct hci_uart *hu)
 {
 	int err, retry = 3;
@@ -674,6 +693,8 @@ static int ll_setup(struct hci_uart *hu)
 
 	lldev = serdev_device_get_drvdata(serdev);
 
+	hu->hdev->set_bdaddr = ll_set_bdaddr;
+
 	serdev_device_set_flow_control(serdev, true);
 
 	do {
-- 
2.7.4

[PATCH v3 2/3] dt-bindings: Add optional nvmem BD address bindings to ti,wlink-st

[David Lechner]

This adds optional nvmem consumer properties to the ti,wlink-st device tree
bindings to allow specifying the BD address.

Reviewed-by: Rob Herring <robh-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Signed-off-by: David Lechner <david-nq/r/kbU++upp/zk7JDF2g@public.gmane.org>
---
 Documentation/devicetree/bindings/net/ti,wilink-st.txt | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/ti,wilink-st.txt b/Documentation/devicetree/bindings/net/ti,wilink-st.txt
index 1649c1f..a45a508 100644
--- a/Documentation/devicetree/bindings/net/ti,wilink-st.txt
+++ b/Documentation/devicetree/bindings/net/ti,wilink-st.txt
@@ -32,6 +32,9 @@ Optional properties:
    See ../clocks/clock-bindings.txt for details.
  - clock-names : Must include the following entry:
    "ext_clock" (External clock provided to the TI combo chip).
+ - nvmem-cells: phandle to nvmem data cell that contains a 6 byte BD address
+   with the most significant byte first (big-endian).
+ - nvmem-cell-names: "bd-address" (required when nvmem-cells is specified)
 
 Example:
 
@@ -43,5 +46,7 @@ Example:
 		enable-gpios = <&gpio1 7 GPIO_ACTIVE_HIGH>;
 		clocks = <&clk32k_wl18xx>;
 		clock-names = "ext_clock";
+		nvmem-cells = <&bd_address>;
+		nvmem-cell-names = "bd-address";
 	};
 };
-- 
2.7.4

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[PATCH] Bluetooth: hci_ll: Add optional nvmem BD address source

[David Lechner]

This adds an optional nvmem consumer to get a BD address from an external
source. The BD 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@lechnology.com>
---
 drivers/bluetooth/hci_ll.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)

diff --git a/drivers/bluetooth/hci_ll.c b/drivers/bluetooth/hci_ll.c
index c948e8d..ed042ae 100644
--- a/drivers/bluetooth/hci_ll.c
+++ b/drivers/bluetooth/hci_ll.c
@@ -53,6 +53,7 @@
 #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"
 
@@ -90,6 +91,7 @@ struct ll_device {
 	struct serdev_device *serdev;
 	struct gpio_desc *enable_gpio;
 	struct clk *ext_clk;
+	bdaddr_t bdaddr;
 };
 
 struct ll_struct {
@@ -719,6 +721,18 @@ static int ll_setup(struct hci_uart *hu)
 	if (err)
 		return err;
 
+	/* Set BD address if one was specified at probe */
+	if (!bacmp(&lldev->bdaddr, BDADDR_NONE)) {
+		/* This means that there was an error getting the BD address
+		 * during probe, so mark the device as having a bad address.
+		 */
+		set_bit(HCI_QUIRK_INVALID_BDADDR, &hu->hdev->quirks);
+	} else if (bacmp(&lldev->bdaddr, BDADDR_ANY)) {
+		err = ll_set_bdaddr(hu->hdev, &lldev->bdaddr);
+		if (err)
+			set_bit(HCI_QUIRK_INVALID_BDADDR, &hu->hdev->quirks);
+	}
+
 	/* Operational speed if any */
 	if (hu->oper_speed)
 		speed = hu->oper_speed;
@@ -749,6 +763,7 @@ 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);
@@ -770,6 +785,52 @@ 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 BD address from nvram */
+	bdaddr_cell = nvmem_cell_get(&serdev->dev, "bd-address");
+	if (IS_ERR(bdaddr_cell)) {
+		int err = PTR_ERR(bdaddr_cell);
+
+		if (err == -EPROBE_DEFER)
+			return err;
+
+		/* ENOENT means there is no matching nvmem cell and ENOSYS
+		 * means that nvmem is not enabled in the kernel configuration.
+		 */
+		if (err != -ENOENT && err != -ENOSYS) {
+			/* If there was some other error, give userspace a
+			 * chance to fix the problem instead of failing to load
+			 * the driver. Using BDADDR_NONE as a flag that is
+			 * tested later in the setup function.
+			 */
+			dev_warn(&serdev->dev,
+				 "Failed to get \"bd-address\" nvmem cell (%d)\n",
+				 err);
+			bacpy(&lldev->bdaddr, BDADDR_NONE);
+		}
+	} else {
+		bdaddr_t *bdaddr;
+		int len;
+
+		bdaddr = nvmem_cell_read(bdaddr_cell, &len);
+		nvmem_cell_put(bdaddr_cell);
+		if (IS_ERR(bdaddr)) {
+			dev_err(&serdev->dev, "Failed to read nvmem bd-address\n");
+			return PTR_ERR(bdaddr);
+		}
+		if (len != sizeof(bdaddr_t)) {
+			dev_err(&serdev->dev, "Invalid nvmem bd-address length\n");
+			kfree(bdaddr);
+			return -EINVAL;
+		}
+
+		/* As per the device tree bindings, the value from nvmem is
+		 * expected to be MSB first, but in the kernel it is expected
+		 * that bdaddr_t is LSB first.
+		 */
+		baswap(&lldev->bdaddr, bdaddr);
+		kfree(bdaddr);
+	}
+
 	return hci_uart_register_device(hu, &llp);
 }
 
-- 
2.7.4

Re: [PATCH v3 0/3] Bluetooth: hci_ll: Get BD address from NVMEM

[Marcel Holtmann]

Hi David,

> This series adds supporting getting the BD address from a NVMEM provider
> for "LL" HCI controllers (Texas Instruments).
> 
> v3 changes:
> * Additional comments on why swapping bytes is needed.
> * Fixed comment style and trailing whitespace.
> * Rework error handling for nvmem cell code.
> 
> v2 changes:
> * Fixed typos in dt-bindings
> * Use "bd-address" instead of "mac-address"
> * Updated dt-bindings to specify the byte order of "bd-address"
> * New patch "Bluetooth: hci_ll: add support for setting public address"
> * Dropped patch "Bluetooth: hci_ll: add constant for vendor-specific command"
>  that is already in bluetooth-next
> * Rework error handling
> * Use bdaddr_t, bacmp and other bluetooth utils
> 
> David Lechner (3):
>  Bluetooth: hci_ll: add support for setting public address
>  dt-bindings: Add optional nvmem BD address bindings to ti,wlink-st
>  Bluetooth: hci_ll: Add optional nvmem BD address source
> 
> .../devicetree/bindings/net/ti,wilink-st.txt       |  5 ++
> drivers/bluetooth/hci_ll.c                         | 77 ++++++++++++++++++++++
> 2 files changed, 82 insertions(+)

I applied to first 2 patches to bluetooth-next tree, but the 3rd is throwing a warning.

  CC      drivers/bluetooth/hci_ll.o
drivers/bluetooth/hci_ll.c: In function ‘hci_ti_probe’:
drivers/bluetooth/hci_ll.c:814:41: error: passing argument 2 of ‘nvmem_cell_read’ from incompatible pointer type [-Werror=incompatible-pointer-types]
   bdaddr = nvmem_cell_read(bdaddr_cell, &len);
                                         ^
In file included from drivers/bluetooth/hci_ll.c:56:0:
./include/linux/nvmem-consumer.h:81:21: note: expected ‘size_t * {aka long unsigned int *}’ but argument is of type ‘int *’
 static inline void *nvmem_cell_read(struct nvmem_cell *cell, size_t *len)
                     ^~~~~~~~~~~~~~~

Regards

Marcel