[PATCH 0/2] Bluetooth for the RTL8852BS on BPI-F3

[PATCH 0/2] Bluetooth for the RTL8852BS on BPI-F3

[Frédéric Mahé]

The BPI-F3 (SpacemiT K1) carries an RTL8852BS Wi-Fi + Bluetooth module.
Wi-Fi (SDIO) has no upstream driver, but Bluetooth on UART works with
the existing hci_h5/btrtl code and linux-firmware's rtl8852bs files.

Patch 1 documents the compatible, with rtl8822cs-bt as fallback, so no
driver change is needed. Patch 2 enables it on the BPI-F3.

GPIO usage was tested one line at a time: GPIO 63 is the power/enable
line and GPIO 64 the device wake line. The vendor DT also drives
GPIO 65 and GPIO 67; Bluetooth works without them (and RSSI is the
same with GPIO 67 high or low), so they are left out.

Frédéric Mahé (2):
  dt-bindings: net: bluetooth: realtek: Add RTL8852BS
  riscv: dts: spacemit: enable Bluetooth on BPI-F3

 .../bindings/net/bluetooth/realtek,bluetooth.yaml | 11 +++++++----
 arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts   | 15 +++++++++++++++
 2 files changed, 22 insertions(+), 4 deletions(-)


base-commit: 6628e7d4c6b25c8d18f1345e3a20d21829aae7e4
-- 
2.47.3

[PATCH 1/2] dt-bindings: net: bluetooth: realtek: Add RTL8852BS

[Frédéric Mahé]

The RTL8852BS is a Wi-Fi 6 + Bluetooth 5.2 chip with Wi-Fi on SDIO
and Bluetooth on UART (H5). Its Bluetooth part works with the
RTL8822CS driver data, so use realtek,rtl8822cs-bt as fallback.

This patch was prepared with the help of an AI assistant (Claude),
which also ran the tests.

Signed-off-by: Frédéric Mahé <frederic.mahe@cirad.fr>
---
 .../bindings/net/bluetooth/realtek,bluetooth.yaml     | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/Documentation/devicetree/bindings/net/bluetooth/realtek,bluetooth.yaml b/Documentation/devicetree/bindings/net/bluetooth/realtek,bluetooth.yaml
index 7d567122b..ffdf13b05 100644
--- a/Documentation/devicetree/bindings/net/bluetooth/realtek,bluetooth.yaml
+++ b/Documentation/devicetree/bindings/net/bluetooth/realtek,bluetooth.yaml
@@ -4,16 +4,16 @@
 $id: http://devicetree.org/schemas/net/bluetooth/realtek,bluetooth.yaml#
 $schema: http://devicetree.org/meta-schemas/core.yaml#
 
-title: RTL8723BS/RTL8723CS/RTL8821CS/RTL8822CS Bluetooth
+title: RTL8723BS/RTL8723CS/RTL8821CS/RTL8822CS/RTL8852BS Bluetooth
 
 maintainers:
   - Vasily Khoruzhick <anarsoul@gmail.com>
   - Alistair Francis <alistair@alistair23.me>
 
 description:
-  RTL8723BS/RTL8723CS/RTL8821CS/RTL8822CS is a WiFi + BT chip. WiFi part
-  is connected over SDIO, while BT is connected over serial. It speaks
-  H5 protocol with few extra commands to upload firmware and change
+  RTL8723BS/RTL8723CS/RTL8821CS/RTL8822CS/RTL8852BS is a WiFi + BT chip.
+  WiFi part is connected over SDIO, while BT is connected over serial. It
+  speaks H5 protocol with few extra commands to upload firmware and change
   module speed.
 
 properties:
@@ -28,6 +28,9 @@ properties:
           - enum:
               - realtek,rtl8821cs-bt
           - const: realtek,rtl8723bs-bt
+      - items:
+          - const: realtek,rtl8852bs-bt
+          - const: realtek,rtl8822cs-bt
 
   device-wake-gpios:
     maxItems: 1
-- 
2.47.3

[PATCH 2/2] riscv: dts: spacemit: enable Bluetooth on BPI-F3

[Frédéric Mahé]

The BPI-F3 has an RTL8852BS module whose Bluetooth part is on UART2,
with hardware flow control. GPIO 63 powers Bluetooth on and GPIO 64
is the device wake line.

The firmware config switches the UART to 1.5 Mbaud, so take the UART2
clock from the 48 MHz slow_uart2 clock.

Tested with a laptop: scan, pairing, and l2ping in both directions,
including incoming connections while the UART is runtime suspended.
An 8-hour soak (an HCI command every 20 s) showed no errors.

This patch was prepared with the help of an AI assistant (Claude),
which also ran the tests.

Signed-off-by: Frédéric Mahé <frederic.mahe@cirad.fr>
---
 arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
index 58035d886..280adc9dc 100644
--- a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
+++ b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
@@ -383,6 +383,21 @@ &uart0 {
 	status = "okay";
 };
 
+&uart2 {
+	assigned-clocks = <&syscon_apbc CLK_UART2>;
+	assigned-clock-parents = <&syscon_mpmu CLK_SLOW_UART2>;
+	pinctrl-names = "default";
+	pinctrl-0 = <&uart2_0_cfg>, <&uart2_0_cts_rts_cfg>;
+	uart-has-rtscts;
+	status = "okay";
+
+	bluetooth {
+		compatible = "realtek,rtl8852bs-bt", "realtek,rtl8822cs-bt";
+		enable-gpios = <&gpio K1_GPIO(63) GPIO_ACTIVE_HIGH>;
+		device-wake-gpios = <&gpio K1_GPIO(64) GPIO_ACTIVE_HIGH>;
+	};
+};
+
 &usbphy2 {
 	status = "okay";
 };
-- 
2.47.3

Re: [PATCH 2/2] riscv: dts: spacemit: enable Bluetooth on BPI-F3

[Troy Mitchell]

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On Tue, 10 Nov 2026 08:46:07 +0100, Frédéric Mahé wrote:
> The BPI-F3 has an RTL8852BS module whose Bluetooth part is on UART2,
> with hardware flow control. GPIO 63 powers Bluetooth on and GPIO 64
> is the device wake line.
>
> The firmware config switches the UART to 1.5 Mbaud, so take the UART2
> clock from the 48 MHz slow_uart2 clock.
slow_uart2 is a programmable divider (MPMU_SUCCR_1), not a fixed
48 MHz clock. Its rate is whatever the bootloader left there.

[...]
> diff --git a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
> index 58035d886..280adc9dc 100644
> --- a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
> +++ b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
> @@ -383,6 +383,21 @@ &uart0 {
>  	status = "okay";
>  };
>  
> +&uart2 {
> +	assigned-clocks = <&syscon_apbc CLK_UART2>;
> +	assigned-clock-parents = <&syscon_mpmu CLK_SLOW_UART2>;
Please add CLK_SLOW_UART2 to assigned-clocks and set it explicitly:

	assigned-clock-rates = <0>, <48000000>;

> +	pinctrl-names = "default";
> +	pinctrl-0 = <&uart2_0_cfg>, <&uart2_0_cts_rts_cfg>;
> +	uart-has-rtscts;
> +	status = "okay";
> +
> +	bluetooth {
> +		compatible = "realtek,rtl8852bs-bt", "realtek,rtl8822cs-bt";
> +		enable-gpios = <&gpio K1_GPIO(63) GPIO_ACTIVE_HIGH>;
> +		device-wake-gpios = <&gpio K1_GPIO(64) GPIO_ACTIVE_HIGH>;
> +	};
> +};

-- 
Troy Mitchell

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RE: Bluetooth for the RTL8852BS on BPI-F3

[bluez.test.bot]

[-- Attachment #1: Type: text/plain, Size: 1833 bytes --]

This is automated email and please do not reply to this email!

Dear submitter,

Thank you for submitting the patches to the linux bluetooth mailing list.
This is a CI test results with your patch series:
PW Link:https://patchwork.kernel.org/series/1206953/

---Test result---

Test Summary:
CheckPatch                    PASS      1.06 seconds
VerifyFixes                   PASS      0.10 seconds
VerifySignedoff               PASS      0.11 seconds
GitLint                       PASS      0.51 seconds
SubjectPrefix                 FAIL      0.21 seconds
BuildKernel                   PASS      17.46 seconds
CheckAllWarning               PASS      20.54 seconds
CheckSparse                   PASS      22.27 seconds
BuildKernel32                 PASS      18.16 seconds
CheckKernelLLVM               PASS      18.28 seconds
TestRunnerSetup               PASS      420.43 seconds
TestRunner_l2cap-tester       PASS      12.59 seconds
TestRunner_iso-tester         PASS      8.89 seconds
TestRunner_bnep-tester        PASS      2.75 seconds
TestRunner_mgmt-tester        PASS      81.37 seconds
TestRunner_rfcomm-tester      PASS      3.96 seconds
TestRunner_sco-tester         PASS      4.94 seconds
TestRunner_ioctl-tester       PASS      4.21 seconds
TestRunner_mesh-tester        PASS      5.13 seconds
TestRunner_smp-tester         PASS      3.91 seconds
TestRunner_userchan-tester    PASS      2.82 seconds
TestRunner_6lowpan-tester     PASS      3.94 seconds
IncrementalBuild              PASS      19.36 seconds

Details
##############################
Test: SubjectPrefix - FAIL
Desc: Check subject contains "Bluetooth" prefix
Output:
"Bluetooth: " prefix is not specified in the subject
"Bluetooth: " prefix is not specified in the subject


https://github.com/bluez/bluetooth-next/pull/1102

---
Regards,
Linux Bluetooth

Re: [PATCH 1/2] dt-bindings: net: bluetooth: realtek: Add RTL8852BS

[Conor Dooley]

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Acked-by: Conor Dooley <conor.dooley@microchip.com>
pw-bot: not-applicable

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Re: [PATCH 1/2] dt-bindings: net: bluetooth: realtek: Add RTL8852BS

[Alistair]

On Tue, 2026-11-10 at 08:46 +0100, Frédéric Mahé wrote:
> The RTL8852BS is a Wi-Fi 6 + Bluetooth 5.2 chip with Wi-Fi on SDIO
> and Bluetooth on UART (H5). Its Bluetooth part works with the
> RTL8822CS driver data, so use realtek,rtl8822cs-bt as fallback.
> 
> This patch was prepared with the help of an AI assistant (Claude),
> which also ran the tests.
> 
> Signed-off-by: Frédéric Mahé <frederic.mahe@cirad.fr>

Reviewed-by: Alistair Francis <alistair@alistair23.me>

Alistair

> ---
>  .../bindings/net/bluetooth/realtek,bluetooth.yaml     | 11 +++++++--
> --
>  1 file changed, 7 insertions(+), 4 deletions(-)
> 
> diff --git
> a/Documentation/devicetree/bindings/net/bluetooth/realtek,bluetooth.y
> aml
> b/Documentation/devicetree/bindings/net/bluetooth/realtek,bluetooth.y
> aml
> index 7d567122b..ffdf13b05 100644
> ---
> a/Documentation/devicetree/bindings/net/bluetooth/realtek,bluetooth.y
> aml
> +++
> b/Documentation/devicetree/bindings/net/bluetooth/realtek,bluetooth.y
> aml
> @@ -4,16 +4,16 @@
>  $id:
> http://devicetree.org/schemas/net/bluetooth/realtek,bluetooth.yaml#
>  $schema: http://devicetree.org/meta-schemas/core.yaml#
>  
> -title: RTL8723BS/RTL8723CS/RTL8821CS/RTL8822CS Bluetooth
> +title: RTL8723BS/RTL8723CS/RTL8821CS/RTL8822CS/RTL8852BS Bluetooth
>  
>  maintainers:
>    - Vasily Khoruzhick <anarsoul@gmail.com>
>    - Alistair Francis <alistair@alistair23.me>
>  
>  description:
> -  RTL8723BS/RTL8723CS/RTL8821CS/RTL8822CS is a WiFi + BT chip. WiFi
> part
> -  is connected over SDIO, while BT is connected over serial. It
> speaks
> -  H5 protocol with few extra commands to upload firmware and change
> +  RTL8723BS/RTL8723CS/RTL8821CS/RTL8822CS/RTL8852BS is a WiFi + BT
> chip.
> +  WiFi part is connected over SDIO, while BT is connected over
> serial. It
> +  speaks H5 protocol with few extra commands to upload firmware and
> change
>    module speed.
>  
>  properties:
> @@ -28,6 +28,9 @@ properties:
>            - enum:
>                - realtek,rtl8821cs-bt
>            - const: realtek,rtl8723bs-bt
> +      - items:
> +          - const: realtek,rtl8852bs-bt
> +          - const: realtek,rtl8822cs-bt
>  
>    device-wake-gpios:
>      maxItems: 1

Re: [PATCH 2/2] riscv: dts: spacemit: enable Bluetooth on BPI-F3

[Frédéric Mahé]

On Tue, Nov 10, 2026 at 08:44:36AM +0000, Troy Mitchell wrote:
> Please add CLK_SLOW_UART2 to assigned-clocks and set it explicitly:
>
> 	assigned-clock-rates = <0>, <48000000>;

Thanks, done in v2:
https://lore.kernel.org/r/20261111094557.443481-1-frederic.mahe@cirad.fr

I checked that the rate is really applied: with 24 MHz in the DT,
slow_uart2 runs at 24 MHz; with 48 MHz, Bluetooth works as before.

Frédéric

RE: Bluetooth for the RTL8852BS on BPI-F3

[bluez.test.bot]

[-- Attachment #1: Type: text/plain, Size: 1835 bytes --]

This is automated email and please do not reply to this email!

Dear submitter,

Thank you for submitting the patches to the linux bluetooth mailing list.
This is a CI test results with your patch series:
PW Link:https://patchwork.kernel.org/series/1208172/

---Test result---

Test Summary:
CheckPatch                    PASS      3.16 seconds
VerifyFixes                   PASS      0.19 seconds
VerifySignedoff               PASS      0.13 seconds
GitLint                       PASS      0.72 seconds
SubjectPrefix                 FAIL      2.07 seconds
BuildKernel                   PASS      31.26 seconds
CheckAllWarning               PASS      35.70 seconds
CheckSparse                   PASS      38.72 seconds
BuildKernel32                 PASS      31.87 seconds
CheckKernelLLVM               PASS      44.79 seconds
TestRunnerSetup               PASS      757.58 seconds
TestRunner_l2cap-tester       PASS      13.58 seconds
TestRunner_iso-tester         PASS      13.04 seconds
TestRunner_bnep-tester        PASS      3.20 seconds
TestRunner_mgmt-tester        PASS      90.32 seconds
TestRunner_rfcomm-tester      PASS      5.73 seconds
TestRunner_sco-tester         PASS      6.18 seconds
TestRunner_ioctl-tester       PASS      17.20 seconds
TestRunner_mesh-tester        PASS      7.54 seconds
TestRunner_smp-tester         PASS      7.40 seconds
TestRunner_userchan-tester    PASS      4.28 seconds
TestRunner_6lowpan-tester     PASS      4.58 seconds
IncrementalBuild              PASS      30.54 seconds

Details
##############################
Test: SubjectPrefix - FAIL
Desc: Check subject contains "Bluetooth" prefix
Output:
"Bluetooth: " prefix is not specified in the subject
"Bluetooth: " prefix is not specified in the subject


https://github.com/bluez/bluetooth-next/pull/1110

---
Regards,
Linux Bluetooth