[PATCH v2 0/4] Bluetooth: hci_bcm: Additional changes for BCM4354 support

[PATCH v2 0/4] Bluetooth: hci_bcm: Additional changes for BCM4354 support

[Abhishek Pandit-Subedi]

While adding support for the BCM4354, I discovered a few more things
that weren't working as they should have.

First, we disallow serdev from setting the baudrate on BCM4354. Serdev
sets the oper_speed first before calling hu->setup() in
hci_uart_setup(). On the BCM4354, this results in bcm_setup() failing
when the hci reset times out.

Next, we add support for setting the PCM parameters, which consists of
a pair of vendor specific opcodes to set the pcm parameters. The
documentation for these params are available in the brcm_patchram_plus
package (i.e. https://github.com/balena-os/brcm_patchram_plus). This is
necessary for PCM to work properly.

All changes were tested with rk3288-veyron-minnie.dts.


Changes in v2:
- Use match data to disallow baudrate setting
- Parse pcm parameters by name instead of as a byte string
- Fix prefix for dt-bindings commit

Abhishek Pandit-Subedi (4):
  Bluetooth: hci_bcm: Disallow set_baudrate for BCM4354
  Bluetooth: btbcm: Support pcm configuration
  Bluetooth: hci_bcm: Support pcm params in dts
  dt-bindings: net: broadcom-bluetooth: Add pcm config

 .../bindings/net/broadcom-bluetooth.txt       | 11 ++++
 drivers/bluetooth/btbcm.c                     | 35 +++++++++++
 drivers/bluetooth/btbcm.h                     | 10 ++++
 drivers/bluetooth/hci_bcm.c                   | 58 ++++++++++++++++++-
 4 files changed, 112 insertions(+), 2 deletions(-)

-- 
2.24.0.rc1.363.gb1bccd3e3d-goog

[PATCH v2 1/4] Bluetooth: hci_bcm: Disallow set_baudrate for BCM4354

[Abhishek Pandit-Subedi]

Without updating the patchram, the BCM4354 does not support a higher
operating speed. The normal bcm_setup follows the correct order
(init_speed, patchram and then oper_speed) but the serdev driver will
set the operating speed before calling the hu->setup function. Thus,
for the BCM4354, disallow setting the operating speed before patchram.

Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
---

Changes in v2: None

 drivers/bluetooth/hci_bcm.c | 25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/drivers/bluetooth/hci_bcm.c b/drivers/bluetooth/hci_bcm.c
index 0f851c0dde7f..2114df607cb3 100644
--- a/drivers/bluetooth/hci_bcm.c
+++ b/drivers/bluetooth/hci_bcm.c
@@ -1167,7 +1167,7 @@ static int bcm_remove(struct platform_device *pdev)
 	return 0;
 }
 
-static const struct hci_uart_proto bcm_proto = {
+static struct hci_uart_proto bcm_proto = {
 	.id		= HCI_UART_BCM,
 	.name		= "Broadcom",
 	.manufacturer	= 15,
@@ -1371,6 +1371,24 @@ static struct platform_driver bcm_driver = {
 	},
 };
 
+#define BCM_QUIRK_DISALLOW_SET_BAUDRATE (1 << 0)
+const u32 disallow_set_baudrate = BCM_QUIRK_DISALLOW_SET_BAUDRATE;
+
+static int bcm_check_disallow_set_baudrate(struct serdev_device *serdev)
+{
+	const u32 *quirks = device_get_match_data(&serdev->dev);
+
+	if (quirks) {
+		/* BCM4354 can't run at full speed before patchram. Disallow
+		 * externally setting operating speed.
+		 */
+		if (*quirks & BCM_QUIRK_DISALLOW_SET_BAUDRATE)
+			return 1;
+	}
+
+	return 0;
+}
+
 static int bcm_serdev_probe(struct serdev_device *serdev)
 {
 	struct bcm_device *bcmdev;
@@ -1408,6 +1426,9 @@ static int bcm_serdev_probe(struct serdev_device *serdev)
 	if (err)
 		dev_err(&serdev->dev, "Failed to power down\n");
 
+	if (bcm_check_disallow_set_baudrate(serdev))
+		bcm_proto.set_baudrate = NULL;
+
 	return hci_uart_register_device(&bcmdev->serdev_hu, &bcm_proto);
 }
 
@@ -1424,7 +1445,7 @@ static const struct of_device_id bcm_bluetooth_of_match[] = {
 	{ .compatible = "brcm,bcm4345c5" },
 	{ .compatible = "brcm,bcm4330-bt" },
 	{ .compatible = "brcm,bcm43438-bt" },
-	{ .compatible = "brcm,bcm43540-bt" },
+	{ .compatible = "brcm,bcm43540-bt", .data = &disallow_set_baudrate },
 	{ },
 };
 MODULE_DEVICE_TABLE(of, bcm_bluetooth_of_match);
-- 
2.24.0.rc1.363.gb1bccd3e3d-goog

Re: [PATCH v2 1/4] Bluetooth: hci_bcm: Disallow set_baudrate for BCM4354

[Marcel Holtmann]

Hi Abhishek,

> Without updating the patchram, the BCM4354 does not support a higher
> operating speed. The normal bcm_setup follows the correct order
> (init_speed, patchram and then oper_speed) but the serdev driver will
> set the operating speed before calling the hu->setup function. Thus,
> for the BCM4354, disallow setting the operating speed before patchram.
> 
> Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> ---
> 
> Changes in v2: None
> 
> drivers/bluetooth/hci_bcm.c | 25 +++++++++++++++++++++++--
> 1 file changed, 23 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/bluetooth/hci_bcm.c b/drivers/bluetooth/hci_bcm.c
> index 0f851c0dde7f..2114df607cb3 100644
> --- a/drivers/bluetooth/hci_bcm.c
> +++ b/drivers/bluetooth/hci_bcm.c
> @@ -1167,7 +1167,7 @@ static int bcm_remove(struct platform_device *pdev)
> 	return 0;
> }
> 
> -static const struct hci_uart_proto bcm_proto = {
> +static struct hci_uart_proto bcm_proto = {
> 	.id		= HCI_UART_BCM,
> 	.name		= "Broadcom",
> 	.manufacturer	= 15,
> @@ -1371,6 +1371,24 @@ static struct platform_driver bcm_driver = {
> 	},
> };
> 
> +#define BCM_QUIRK_DISALLOW_SET_BAUDRATE (1 << 0)
> +const u32 disallow_set_baudrate = BCM_QUIRK_DISALLOW_SET_BAUDRATE;
> +
> +static int bcm_check_disallow_set_baudrate(struct serdev_device *serdev)
> +{
> +	const u32 *quirks = device_get_match_data(&serdev->dev);
> +
> +	if (quirks) {
> +		/* BCM4354 can't run at full speed before patchram. Disallow
> +		 * externally setting operating speed.
> +		 */
> +		if (*quirks & BCM_QUIRK_DISALLOW_SET_BAUDRATE)
> +			return 1;
> +	}
> +
> +	return 0;
> +}
> +
> static int bcm_serdev_probe(struct serdev_device *serdev)
> {
> 	struct bcm_device *bcmdev;
> @@ -1408,6 +1426,9 @@ static int bcm_serdev_probe(struct serdev_device *serdev)
> 	if (err)
> 		dev_err(&serdev->dev, "Failed to power down\n");
> 
> +	if (bcm_check_disallow_set_baudrate(serdev))
> +		bcm_proto.set_baudrate = NULL;
> +

this change is not allowed since bcm_proto is on purpose const.

> 	return hci_uart_register_device(&bcmdev->serdev_hu, &bcm_proto);
> }
> 
> @@ -1424,7 +1445,7 @@ static const struct of_device_id bcm_bluetooth_of_match[] = {
> 	{ .compatible = "brcm,bcm4345c5" },
> 	{ .compatible = "brcm,bcm4330-bt" },
> 	{ .compatible = "brcm,bcm43438-bt" },
> -	{ .compatible = "brcm,bcm43540-bt" },
> +	{ .compatible = "brcm,bcm43540-bt", .data = &disallow_set_baudrate },
> 	{ },
> };
> MODULE_DEVICE_TABLE(of, bcm_bluetooth_of_match);

So I would prefer if we do this in a more generic from that will make this easy to extend in the future. Similar to what hci_qca.c does actually with defining a separate struct for the module differences.

struct bcm_device_data (
	bool no_early_oper_speed;
};

static const struct bcm_device_data bcm43540_device {
	.no_early_oper_speed = true,
};

static const struct of_device_id bcm_bluetooth_of_match[] = {
	..
	{ .compatible = "brcm,bcm43540-bt", .data = &bcm43540_device },
	( },
};

And then load the struct in serdev probe as pointer and check its existence and add the struct bcm_device_data to struct bcm_device so it can be referenced when you change the baudrate.

Regards

Marcel

[PATCH v2 2/4] Bluetooth: btbcm: Support pcm configuration

[Abhishek Pandit-Subedi]

Add BCM vendor specific commands to configure PCM.

Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
---

Changes in v2: None

 drivers/bluetooth/btbcm.c | 35 +++++++++++++++++++++++++++++++++++
 drivers/bluetooth/btbcm.h | 10 ++++++++++
 2 files changed, 45 insertions(+)

diff --git a/drivers/bluetooth/btbcm.c b/drivers/bluetooth/btbcm.c
index 2d2e6d862068..f052518f7b0c 100644
--- a/drivers/bluetooth/btbcm.c
+++ b/drivers/bluetooth/btbcm.c
@@ -105,6 +105,41 @@ int btbcm_set_bdaddr(struct hci_dev *hdev, const bdaddr_t *bdaddr)
 }
 EXPORT_SYMBOL_GPL(btbcm_set_bdaddr);
 
+int btbcm_set_pcm_params(struct hci_dev *hdev,
+			 const struct bcm_set_pcm_int_params *int_params,
+			 const struct bcm_set_pcm_format_params *format_params)
+{
+	struct sk_buff *skb;
+	int err;
+
+	if (int_params) {
+		skb = __hci_cmd_sync(hdev, 0xfc1c, 5, int_params,
+				     HCI_INIT_TIMEOUT);
+		if (IS_ERR(skb)) {
+			err = PTR_ERR(skb);
+			bt_dev_err(hdev, "BCM: Set PCM int params failed (%d)",
+				   err);
+			return err;
+		}
+		kfree_skb(skb);
+	}
+
+	if (format_params) {
+		skb = __hci_cmd_sync(hdev, 0xfc1e, 5, format_params,
+				     HCI_INIT_TIMEOUT);
+		if (IS_ERR(skb)) {
+			err = PTR_ERR(skb);
+			bt_dev_err(hdev, "BCM: Set PCM data params failed (%d)",
+				   err);
+			return err;
+		}
+		kfree_skb(skb);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(btbcm_set_pcm_params);
+
 int btbcm_patchram(struct hci_dev *hdev, const struct firmware *fw)
 {
 	const struct hci_command_hdr *cmd;
diff --git a/drivers/bluetooth/btbcm.h b/drivers/bluetooth/btbcm.h
index d204be8a84bf..f0a63c65544e 100644
--- a/drivers/bluetooth/btbcm.h
+++ b/drivers/bluetooth/btbcm.h
@@ -54,6 +54,9 @@ struct bcm_set_pcm_format_params {
 int btbcm_check_bdaddr(struct hci_dev *hdev);
 int btbcm_set_bdaddr(struct hci_dev *hdev, const bdaddr_t *bdaddr);
 int btbcm_patchram(struct hci_dev *hdev, const struct firmware *fw);
+int btbcm_set_pcm_params(struct hci_dev *hdev,
+			 const struct bcm_set_pcm_int_params *int_params,
+			 const struct bcm_set_pcm_format_params *format_params);
 
 int btbcm_setup_patchram(struct hci_dev *hdev);
 int btbcm_setup_apple(struct hci_dev *hdev);
@@ -74,6 +77,13 @@ static inline int btbcm_set_bdaddr(struct hci_dev *hdev, const bdaddr_t *bdaddr)
 	return -EOPNOTSUPP;
 }
 
+int btbcm_set_pcm_params(struct hci_dev *hdev,
+			 const struct bcm_set_pcm_int_params *int_params,
+			 const struct bcm_set_pcm_format_params *format_params)
+{
+	return -EOPNOTSUPP;
+}
+
 static inline int btbcm_patchram(struct hci_dev *hdev, const struct firmware *fw)
 {
 	return -EOPNOTSUPP;
-- 
2.24.0.rc1.363.gb1bccd3e3d-goog

Re: [PATCH v2 2/4] Bluetooth: btbcm: Support pcm configuration

[Marcel Holtmann]

Hi Abhishek,

> Add BCM vendor specific commands to configure PCM.

please be a bit more descriptive and you can also add the command decoding from btmon here if you like.

> 
> Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> ---
> 
> Changes in v2: None
> 
> drivers/bluetooth/btbcm.c | 35 +++++++++++++++++++++++++++++++++++
> drivers/bluetooth/btbcm.h | 10 ++++++++++
> 2 files changed, 45 insertions(+)
> 
> diff --git a/drivers/bluetooth/btbcm.c b/drivers/bluetooth/btbcm.c
> index 2d2e6d862068..f052518f7b0c 100644
> --- a/drivers/bluetooth/btbcm.c
> +++ b/drivers/bluetooth/btbcm.c
> @@ -105,6 +105,41 @@ int btbcm_set_bdaddr(struct hci_dev *hdev, const bdaddr_t *bdaddr)
> }
> EXPORT_SYMBOL_GPL(btbcm_set_bdaddr);
> 
> +int btbcm_set_pcm_params(struct hci_dev *hdev,
> +			 const struct bcm_set_pcm_int_params *int_params,
> +			 const struct bcm_set_pcm_format_params *format_params)
> +{
> +	struct sk_buff *skb;
> +	int err;
> +
> +	if (int_params) {
> +		skb = __hci_cmd_sync(hdev, 0xfc1c, 5, int_params,
> +				     HCI_INIT_TIMEOUT);
> +		if (IS_ERR(skb)) {
> +			err = PTR_ERR(skb);
> +			bt_dev_err(hdev, "BCM: Set PCM int params failed (%d)",
> +				   err);
> +			return err;
> +		}
> +		kfree_skb(skb);
> +	}

Actually lets do btbcm_set_pcm_int_params and focus on the ones you are using right now.

Regards

Marcel

[PATCH v2 3/4] Bluetooth: hci_bcm: Support pcm params in dts

[Abhishek Pandit-Subedi]

BCM chips may require configuration of PCM to operate correctly and
there is a vendor specific HCI command to do this. Add support in the
hci_bcm driver to parse this from devicetree and configure the chip.

Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
---

Changes in v2: None

 drivers/bluetooth/hci_bcm.c | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/drivers/bluetooth/hci_bcm.c b/drivers/bluetooth/hci_bcm.c
index 2114df607cb3..46e4793fc234 100644
--- a/drivers/bluetooth/hci_bcm.c
+++ b/drivers/bluetooth/hci_bcm.c
@@ -79,6 +79,8 @@
  * @hu: pointer to HCI UART controller struct,
  *	used to disable flow control during runtime suspend and system sleep
  * @is_suspended: whether flow control is currently disabled
+ * @has_pcm_params: whether PCM parameters need to be configured
+ * @pcm_params: PCM and routing parameters
  */
 struct bcm_device {
 	/* Must be the first member, hci_serdev.c expects this. */
@@ -112,6 +114,9 @@ struct bcm_device {
 	struct hci_uart		*hu;
 	bool			is_suspended;
 #endif
+
+	bool				has_pcm_params;
+	struct bcm_set_pcm_int_params	pcm_params;
 };
 
 /* generic bcm uart resources */
@@ -576,6 +581,17 @@ static int bcm_setup(struct hci_uart *hu)
 			host_set_baudrate(hu, speed);
 	}
 
+	/* PCM parameters if any*/
+	if (bcm->dev && bcm->dev->has_pcm_params) {
+		err = btbcm_set_pcm_params(hu->hdev, &bcm->dev->pcm_params,
+					   NULL);
+
+		if (err) {
+			bt_dev_info(hu->hdev, "BCM: Set pcm params failed (%d)",
+				    err);
+		}
+	}
+
 finalize:
 	release_firmware(fw);
 
@@ -1112,7 +1128,24 @@ static int bcm_acpi_probe(struct bcm_device *dev)
 
 static int bcm_of_probe(struct bcm_device *bdev)
 {
+	int err;
+
 	device_property_read_u32(bdev->dev, "max-speed", &bdev->oper_speed);
+
+	err = device_property_read_u8(bdev->dev, "brcm,sco-routing",
+				      &bdev->pcm_params.routing);
+	if (!err)
+		bdev->has_pcm_params = true;
+
+	device_property_read_u8(bdev->dev, "brcm,pcm-interface-rate",
+				&bdev->pcm_params.rate);
+	device_property_read_u8(bdev->dev, "brcm,pcm-frame-type",
+				&bdev->pcm_params.frame_sync);
+	device_property_read_u8(bdev->dev, "brcm,pcm-sync-mode",
+				&bdev->pcm_params.sync_mode);
+	device_property_read_u8(bdev->dev, "brcm,pcm-clock-mode",
+				&bdev->pcm_params.clock_mode);
+
 	return 0;
 }
 
-- 
2.24.0.rc1.363.gb1bccd3e3d-goog

[PATCH v2 4/4] dt-bindings: net: broadcom-bluetooth: Add pcm config

[Abhishek Pandit-Subedi]

Add documentation for pcm parameters.

Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>

---

Changes in v2:
- Use match data to disallow baudrate setting
- Parse pcm parameters by name instead of as a byte string
- Fix prefix for dt-bindings commit

 .../devicetree/bindings/net/broadcom-bluetooth.txt    | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/broadcom-bluetooth.txt b/Documentation/devicetree/bindings/net/broadcom-bluetooth.txt
index c749dc297624..b5de8a6a3980 100644
--- a/Documentation/devicetree/bindings/net/broadcom-bluetooth.txt
+++ b/Documentation/devicetree/bindings/net/broadcom-bluetooth.txt
@@ -29,6 +29,11 @@ Optional properties:
    - "lpo": external low power 32.768 kHz clock
  - vbat-supply: phandle to regulator supply for VBAT
  - vddio-supply: phandle to regulator supply for VDDIO
+ - brcm,sco-routing: 0-3 (PCM, Transport, Codec, I2S)
+ - brcm,pcm-interface-rate: 0-4 (128KBps, 256KBps, 512KBps, 1024KBps, 2048KBps)
+ - brcm,pcm-frame-type: 0-1 (short, long)
+ - brcm,pcm-sync-mode: 0-1 (slave, master)
+ - brcm,pcm-clock-mode: 0-1 (slave, master)
 
 
 Example:
@@ -40,5 +45,11 @@ Example:
        bluetooth {
                compatible = "brcm,bcm43438-bt";
                max-speed = <921600>;
+
+               brcm,sco-routing = [01];
+               brcm,pcm-interface-rate = [02];
+               brcm,pcm-frame-type = [00];
+               brcm,pcm-sync-mode = [01];
+               brcm,pcm-clock-mode = [01];
        };
 };
-- 
2.24.0.rc1.363.gb1bccd3e3d-goog

Re: [PATCH v2 4/4] dt-bindings: net: broadcom-bluetooth: Add pcm config

[Marcel Holtmann]

Hi Abhishek,

> Add documentation for pcm parameters.
> 
> Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> 
> ---
> 
> Changes in v2:
> - Use match data to disallow baudrate setting
> - Parse pcm parameters by name instead of as a byte string
> - Fix prefix for dt-bindings commit
> 
> .../devicetree/bindings/net/broadcom-bluetooth.txt    | 11 +++++++++++
> 1 file changed, 11 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/net/broadcom-bluetooth.txt b/Documentation/devicetree/bindings/net/broadcom-bluetooth.txt
> index c749dc297624..b5de8a6a3980 100644
> --- a/Documentation/devicetree/bindings/net/broadcom-bluetooth.txt
> +++ b/Documentation/devicetree/bindings/net/broadcom-bluetooth.txt
> @@ -29,6 +29,11 @@ Optional properties:
>    - "lpo": external low power 32.768 kHz clock
>  - vbat-supply: phandle to regulator supply for VBAT
>  - vddio-supply: phandle to regulator supply for VDDIO
> + - brcm,sco-routing: 0-3 (PCM, Transport, Codec, I2S)
> + - brcm,pcm-interface-rate: 0-4 (128KBps, 256KBps, 512KBps, 1024KBps, 2048KBps)
> + - brcm,pcm-frame-type: 0-1 (short, long)
> + - brcm,pcm-sync-mode: 0-1 (slave, master)
> + - brcm,pcm-clock-mode: 0-1 (slave, master)

should we do brcm,bt-sco-routing etc.

Regards

Marcel

[PATCH v2 2/4] Bluetooth: btbcm: Support pcm configuration

[Marcel Holtmann]

From: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>

Add BCM vendor specific command to configure PCM parameters. The new
vendor opcode allows us to set the sco routing, the pcm interface rate,
and a few other pcm specific options (frame sync, sync mode, and clock
mode). See broadcom-bluetooth.txt in Documentation for more information
about valid values for those settings.

Here is an example trace where this opcode was used to configure
a BCM4354:

        < HCI Command: Vendor (0x3f|0x001c) plen 5
                01 02 00 01 01
        > HCI Event: Command Complete (0x0e) plen 4
        Vendor (0x3f|0x001c) ncmd 1
                Status: Success (0x00)

We can read back the values as well with ocf 0x001d to confirm the
values that were set:
        $ hcitool cmd 0x3f 0x001d
        < HCI Command: ogf 0x3f, ocf 0x001d, plen 0
        > HCI Event: 0x0e plen 9
        01 1D FC 00 01 02 00 01 01

Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
---
 drivers/bluetooth/btbcm.c | 46 +++++++++++++++++++++++++++++++++++++++
 drivers/bluetooth/btbcm.h | 16 ++++++++++++++
 2 files changed, 62 insertions(+)

diff --git a/drivers/bluetooth/btbcm.c b/drivers/bluetooth/btbcm.c
index 8e05706fe5d9..0795a49edfae 100644
--- a/drivers/bluetooth/btbcm.c
+++ b/drivers/bluetooth/btbcm.c
@@ -107,6 +107,52 @@ int btbcm_set_bdaddr(struct hci_dev *hdev, const bdaddr_t *bdaddr)
 }
 EXPORT_SYMBOL_GPL(btbcm_set_bdaddr);
 
+int btbcm_read_pcm_int_params(struct hci_dev *hdev,
+			      struct bcm_set_pcm_int_params *params)
+{
+	struct sk_buff *skb;
+	int err = 0;
+
+	skb = __hci_cmd_sync(hdev, 0xfc1d, 0, NULL, HCI_INIT_TIMEOUT);
+	if (IS_ERR(skb)) {
+		err = PTR_ERR(skb);
+		bt_dev_err(hdev, "BCM: Read PCM int params failed (%d)", err);
+		return err;
+	}
+
+	if (skb->len != 6 || skb->data[0]) {
+		bt_dev_err(hdev, "BCM: Read PCM int params length mismatch");
+		kfree_skb(skb);
+		return -EIO;
+	}
+
+	if (params)
+		memcpy(params, skb->data + 1, 5);
+
+	kfree_skb(skb);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(btbcm_read_pcm_int_params);
+
+int btbcm_write_pcm_int_params(struct hci_dev *hdev,
+			       const struct bcm_set_pcm_int_params *params)
+{
+	struct sk_buff *skb;
+	int err;
+
+	skb = __hci_cmd_sync(hdev, 0xfc1c, 5, params, HCI_INIT_TIMEOUT);
+	if (IS_ERR(skb)) {
+		err = PTR_ERR(skb);
+		bt_dev_err(hdev, "BCM: Write PCM int params failed (%d)", err);
+		return err;
+	}
+	kfree_skb(skb);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(btbcm_write_pcm_int_params);
+
 int btbcm_patchram(struct hci_dev *hdev, const struct firmware *fw)
 {
 	const struct hci_command_hdr *cmd;
diff --git a/drivers/bluetooth/btbcm.h b/drivers/bluetooth/btbcm.h
index d204be8a84bf..3c7dd0765837 100644
--- a/drivers/bluetooth/btbcm.h
+++ b/drivers/bluetooth/btbcm.h
@@ -54,6 +54,10 @@ struct bcm_set_pcm_format_params {
 int btbcm_check_bdaddr(struct hci_dev *hdev);
 int btbcm_set_bdaddr(struct hci_dev *hdev, const bdaddr_t *bdaddr);
 int btbcm_patchram(struct hci_dev *hdev, const struct firmware *fw);
+int btbcm_read_pcm_int_params(struct hci_dev *hdev,
+			      struct bcm_set_pcm_int_params *params);
+int btbcm_write_pcm_int_params(struct hci_dev *hdev,
+			       const struct bcm_set_pcm_int_params *params);
 
 int btbcm_setup_patchram(struct hci_dev *hdev);
 int btbcm_setup_apple(struct hci_dev *hdev);
@@ -74,6 +78,18 @@ static inline int btbcm_set_bdaddr(struct hci_dev *hdev, const bdaddr_t *bdaddr)
 	return -EOPNOTSUPP;
 }
 
+int btbcm_read_pcm_int_params(struct hci_dev *hdev,
+			      struct bcm_set_pcm_int_params *params)
+{
+	return -EOPNOTSUPP;
+}
+
+int btbcm_write_pcm_int_params(struct hci_dev *hdev,
+			       const struct bcm_set_pcm_int_params *params)
+{
+	return -EOPNOTSUPP;
+}
+
 static inline int btbcm_patchram(struct hci_dev *hdev, const struct firmware *fw)
 {
 	return -EOPNOTSUPP;
-- 
2.23.0