[PATCH v3 0/2] Bluetooth: hci_bcm: Autobaud mode support

[PATCH v3 0/2] Bluetooth: hci_bcm: Autobaud mode support

[Hakan Jansson]

Some devices (e.g. CYW5557x) require autobaud mode to enable FW loading.
Autobaud mode can also be required on some boards where the controller
device is using a non-standard baud rate when first powered on.

Only a limited subset of HCI commands are supported in autobaud mode.

These patches add a DT property, "brcm,requires-autobaud-mode", to control
autobaud mode selection.

Changes v2 -> v3:
- Rename DT property and modify description in binding document

Changes v1 -> v2:
- Modify description in binding document

Hakan Jansson (2):
  dt-bindings: net: broadcom-bluetooth: Add property for autobaud mode
  Bluetooth: hci_bcm: Add support for FW loading in autobaud mode

 .../bindings/net/broadcom-bluetooth.yaml      |  7 +++++
 drivers/bluetooth/btbcm.c                     | 31 ++++++++++++++-----
 drivers/bluetooth/btbcm.h                     |  8 ++---
 drivers/bluetooth/hci_bcm.c                   | 16 ++++++++--
 4 files changed, 47 insertions(+), 15 deletions(-)


base-commit: 677fb7525331375ba2f90f4bc94a80b9b6e697a3
-- 
2.25.1

[PATCH v3 1/2] dt-bindings: net: broadcom-bluetooth: Add property for autobaud mode

[Hakan Jansson]

Add property, "brcm,requires-autobaud-mode", to enable autobaud mode
selection.

Some devices (e.g. CYW5557x) require autobaud mode to enable FW loading.
Autobaud mode can also be required on some boards where the controller
device is using a non-standard baud rate when first powered on.

Signed-off-by: Hakan Jansson <hakan.jansson@infineon.com>
---
V2 -> V3:
  - Rename DT property and modify description
    https://lore.kernel.org/linux-devicetree/e6e83743-1441-dc53-fd1f-cdfb9a24932a@linaro.org/

V1 -> V2:
  - Modify property description

 .../devicetree/bindings/net/broadcom-bluetooth.yaml        | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/broadcom-bluetooth.yaml b/Documentation/devicetree/bindings/net/broadcom-bluetooth.yaml
index 5aac094fd217..0a58d0fbcbc4 100644
--- a/Documentation/devicetree/bindings/net/broadcom-bluetooth.yaml
+++ b/Documentation/devicetree/bindings/net/broadcom-bluetooth.yaml
@@ -92,6 +92,13 @@ properties:
        pcm-sync-mode: slave, master
        pcm-clock-mode: slave, master
 
+  brcm,requires-autobaud-mode:
+    type: boolean
+    description:
+      Set this property if autobaud mode is required. Autobaud mode is required
+      if the device's initial baud rate in normal mode is not supported by the
+      host or if the device requires autobaud mode startup before loading FW.
+
   interrupts:
     items:
       - description: Handle to the line HOST_WAKE used to wake
-- 
2.25.1

[PATCH v3 2/2] Bluetooth: hci_bcm: Add support for FW loading in autobaud mode

[Hakan Jansson]

Use the presence of a DT property, "brcm,requires-autobaud-mode", to enable
startup in autobaud mode. If the property is present, the device is started
in autobaud mode by asserting RTS (BT_UART_CTS_N) prior to powering on the
device.

Also prevent the use of unsupported commands for devices started in
autobaud mode. Only a limited subset of HCI commands are supported in
autobaud mode.

Some devices (e.g. CYW5557x) require autobaud mode to enable FW loading.
Autobaud mode can also be required on some boards where the controller
device is using a non-standard baud rate in normal mode when first powered
on.

Signed-off-by: Hakan Jansson <hakan.jansson@infineon.com>
---
V2 -> V3:
  - Rename DT property to "brcm,requires-autobaud-mode"
    https://lore.kernel.org/linux-devicetree/e6e83743-1441-dc53-fd1f-cdfb9a24932a@linaro.org/

V1 -> V2:
  - No changes, submitted as part of updated patch series

 drivers/bluetooth/btbcm.c   | 31 +++++++++++++++++++++++--------
 drivers/bluetooth/btbcm.h   |  8 ++++----
 drivers/bluetooth/hci_bcm.c | 16 +++++++++++++---
 3 files changed, 40 insertions(+), 15 deletions(-)

diff --git a/drivers/bluetooth/btbcm.c b/drivers/bluetooth/btbcm.c
index 76fbb046bdbe..cfe018a6c1fc 100644
--- a/drivers/bluetooth/btbcm.c
+++ b/drivers/bluetooth/btbcm.c
@@ -403,6 +403,13 @@ static int btbcm_read_info(struct hci_dev *hdev)
 	bt_dev_info(hdev, "BCM: chip id %u", skb->data[1]);
 	kfree_skb(skb);
 
+	return 0;
+}
+
+static int btbcm_print_controller_features(struct hci_dev *hdev)
+{
+	struct sk_buff *skb;
+
 	/* Read Controller Features */
 	skb = btbcm_read_controller_features(hdev);
 	if (IS_ERR(skb))
@@ -514,7 +521,7 @@ static const char *btbcm_get_board_name(struct device *dev)
 #endif
 }
 
-int btbcm_initialize(struct hci_dev *hdev, bool *fw_load_done)
+int btbcm_initialize(struct hci_dev *hdev, bool *fw_load_done, bool use_autobaud_mode)
 {
 	u16 subver, rev, pid, vid;
 	struct sk_buff *skb;
@@ -551,9 +558,16 @@ int btbcm_initialize(struct hci_dev *hdev, bool *fw_load_done)
 		if (err)
 			return err;
 	}
-	err = btbcm_print_local_name(hdev);
-	if (err)
-		return err;
+
+	if (!use_autobaud_mode) {
+		err = btbcm_print_controller_features(hdev);
+		if (err)
+			return err;
+
+		err = btbcm_print_local_name(hdev);
+		if (err)
+			return err;
+	}
 
 	bcm_subver_table = (hdev->bus == HCI_USB) ? bcm_usb_subver_table :
 						    bcm_uart_subver_table;
@@ -636,13 +650,13 @@ int btbcm_initialize(struct hci_dev *hdev, bool *fw_load_done)
 }
 EXPORT_SYMBOL_GPL(btbcm_initialize);
 
-int btbcm_finalize(struct hci_dev *hdev, bool *fw_load_done)
+int btbcm_finalize(struct hci_dev *hdev, bool *fw_load_done, bool use_autobaud_mode)
 {
 	int err;
 
 	/* Re-initialize if necessary */
 	if (*fw_load_done) {
-		err = btbcm_initialize(hdev, fw_load_done);
+		err = btbcm_initialize(hdev, fw_load_done, use_autobaud_mode);
 		if (err)
 			return err;
 	}
@@ -658,15 +672,16 @@ EXPORT_SYMBOL_GPL(btbcm_finalize);
 int btbcm_setup_patchram(struct hci_dev *hdev)
 {
 	bool fw_load_done = false;
+	bool use_autobaud_mode = false;
 	int err;
 
 	/* Initialize */
-	err = btbcm_initialize(hdev, &fw_load_done);
+	err = btbcm_initialize(hdev, &fw_load_done, use_autobaud_mode);
 	if (err)
 		return err;
 
 	/* Re-initialize after loading Patch */
-	return btbcm_finalize(hdev, &fw_load_done);
+	return btbcm_finalize(hdev, &fw_load_done, use_autobaud_mode);
 }
 EXPORT_SYMBOL_GPL(btbcm_setup_patchram);
 
diff --git a/drivers/bluetooth/btbcm.h b/drivers/bluetooth/btbcm.h
index 8bf01565fdfc..b4cb24231a20 100644
--- a/drivers/bluetooth/btbcm.h
+++ b/drivers/bluetooth/btbcm.h
@@ -62,8 +62,8 @@ int btbcm_write_pcm_int_params(struct hci_dev *hdev,
 int btbcm_setup_patchram(struct hci_dev *hdev);
 int btbcm_setup_apple(struct hci_dev *hdev);
 
-int btbcm_initialize(struct hci_dev *hdev, bool *fw_load_done);
-int btbcm_finalize(struct hci_dev *hdev, bool *fw_load_done);
+int btbcm_initialize(struct hci_dev *hdev, bool *fw_load_done, bool use_autobaud_mode);
+int btbcm_finalize(struct hci_dev *hdev, bool *fw_load_done, bool use_autobaud_mode);
 
 #else
 
@@ -104,12 +104,12 @@ static inline int btbcm_setup_apple(struct hci_dev *hdev)
 	return 0;
 }
 
-static inline int btbcm_initialize(struct hci_dev *hdev, bool *fw_load_done)
+static inline int btbcm_initialize(struct hci_dev *hdev, bool *fw_load_done, bool use_autobaud_mode)
 {
 	return 0;
 }
 
-static inline int btbcm_finalize(struct hci_dev *hdev, bool *fw_load_done)
+static inline int btbcm_finalize(struct hci_dev *hdev, bool *fw_load_done, bool use_autobaud_mode)
 {
 	return 0;
 }
diff --git a/drivers/bluetooth/hci_bcm.c b/drivers/bluetooth/hci_bcm.c
index 785f445dd60d..4309654f95a5 100644
--- a/drivers/bluetooth/hci_bcm.c
+++ b/drivers/bluetooth/hci_bcm.c
@@ -99,6 +99,7 @@ struct bcm_device_data {
  * @no_early_set_baudrate: don't set_baudrate before setup()
  * @drive_rts_on_open: drive RTS signal on ->open() when platform requires it
  * @pcm_int_params: keep the initial PCM configuration
+ * @use_autobaud_mode: start Bluetooth device in autobaud mode
  */
 struct bcm_device {
 	/* Must be the first member, hci_serdev.c expects this. */
@@ -136,6 +137,7 @@ struct bcm_device {
 #endif
 	bool			no_early_set_baudrate;
 	bool			drive_rts_on_open;
+	bool			use_autobaud_mode;
 	u8			pcm_int_params[5];
 };
 
@@ -472,7 +474,9 @@ static int bcm_open(struct hci_uart *hu)
 
 out:
 	if (bcm->dev) {
-		if (bcm->dev->drive_rts_on_open)
+		if (bcm->dev->use_autobaud_mode)
+			hci_uart_set_flow_control(hu, false);	/* Assert BT_UART_CTS_N */
+		else if (bcm->dev->drive_rts_on_open)
 			hci_uart_set_flow_control(hu, true);
 
 		hu->init_speed = bcm->dev->init_speed;
@@ -564,6 +568,7 @@ static int bcm_setup(struct hci_uart *hu)
 {
 	struct bcm_data *bcm = hu->priv;
 	bool fw_load_done = false;
+	bool use_autobaud_mode = (bcm->dev ? bcm->dev->use_autobaud_mode : 0);
 	unsigned int speed;
 	int err;
 
@@ -572,7 +577,7 @@ static int bcm_setup(struct hci_uart *hu)
 	hu->hdev->set_diag = bcm_set_diag;
 	hu->hdev->set_bdaddr = btbcm_set_bdaddr;
 
-	err = btbcm_initialize(hu->hdev, &fw_load_done);
+	err = btbcm_initialize(hu->hdev, &fw_load_done, use_autobaud_mode);
 	if (err)
 		return err;
 
@@ -616,7 +621,7 @@ static int bcm_setup(struct hci_uart *hu)
 		btbcm_write_pcm_int_params(hu->hdev, &params);
 	}
 
-	err = btbcm_finalize(hu->hdev, &fw_load_done);
+	err = btbcm_finalize(hu->hdev, &fw_load_done, use_autobaud_mode);
 	if (err)
 		return err;
 
@@ -1197,6 +1202,11 @@ static int bcm_acpi_probe(struct bcm_device *dev)
 
 static int bcm_of_probe(struct bcm_device *bdev)
 {
+	bdev->use_autobaud_mode = device_property_read_bool(bdev->dev,
+							    "brcm,requires-autobaud-mode");
+	if (bdev->use_autobaud_mode)
+		bdev->no_early_set_baudrate = true;
+
 	device_property_read_u32(bdev->dev, "max-speed", &bdev->oper_speed);
 	device_property_read_u8_array(bdev->dev, "brcm,bt-pcm-int-params",
 				      bdev->pcm_int_params, 5);
-- 
2.25.1

Re: [PATCH v3 1/2] dt-bindings: net: broadcom-bluetooth: Add property for autobaud mode

[Krzysztof Kozlowski]

On 30/05/2022 17:02, Hakan Jansson wrote:
> Add property, "brcm,requires-autobaud-mode", to enable autobaud mode
> selection.
> 
> Some devices (e.g. CYW5557x) require autobaud mode to enable FW loading.
> Autobaud mode can also be required on some boards where the controller
> device is using a non-standard baud rate when first powered on.
> 
> Signed-off-by: Hakan Jansson <hakan.jansson@infineon.com>


Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>


Best regards,
Krzysztof

Re: [PATCH v3 0/2] Bluetooth: hci_bcm: Autobaud mode support

[patchwork-bot+bluetooth]

Hello:

This series was applied to bluetooth/bluetooth-next.git (master)
by Marcel Holtmann <marcel@holtmann.org>:

On Mon, 30 May 2022 17:02:16 +0200 you wrote:
> Some devices (e.g. CYW5557x) require autobaud mode to enable FW loading.
> Autobaud mode can also be required on some boards where the controller
> device is using a non-standard baud rate when first powered on.
> 
> Only a limited subset of HCI commands are supported in autobaud mode.
> 
> These patches add a DT property, "brcm,requires-autobaud-mode", to control
> autobaud mode selection.
> 
> [...]

Here is the summary with links:
  - [v3,1/2] dt-bindings: net: broadcom-bluetooth: Add property for autobaud mode
    https://git.kernel.org/bluetooth/bluetooth-next/c/6d912cc3c21f
  - [v3,2/2] Bluetooth: hci_bcm: Add support for FW loading in autobaud mode
    https://git.kernel.org/bluetooth/bluetooth-next/c/3f125894bed7

You are awesome, thank you!
-- 
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