[PATCH 3/3] arm64: dts: rockchip: Enable UART8 on rock-3b

[Jonas Karlman]

Hi Tamás,

On 2024-11-12 22:04, Tamás Szűcs wrote:
> Hi Dragan,
> 
> On Tue, Nov 12, 2024 at 4:07 PM Dragan Simic <dsimic at manjaro.org> wrote:
>> Please correct me if I'm wrong, but isn't this UART supposed to be
>> used for the Bluetooth part of an SDIO WiFi + Bluetooth module, in
>> form of a non-standard M.2 module that Radxa sells?
> 
> UART8 is supposed to be used for any radio module connected to the M2E
> connector.
> It will typically be responsible for Bluetooth or BLE but it could be
> 802.15.4 or whatever. In any case, all wanting to use it will need the
> uart8 node enabled.

Do you have any specific sdio+uart module you are testing these changes
with? The pinout for sdio+uart on Radxa's M.2 Key E slot is their own,
pinout for pcie and usb should be closer to a common standard.

https://dl.radxa.com/accessories/wireless-module/ROCKPi_M2_Wireless_Module_Pinout_v10.xlsx

> 
>>
>> With that in mind, I see very little sense in just enabling the UART,
>> without defining the entire Bluetooth interface, which AFAIK produces
> 
> Defining a bluetooth node would hardwire idiosyncrasies of a given
> radio module's Bluetooth core. Sure you could add a sleep clock, all
> kind of sideband signals for wakeups, reset, power down, etc. But hey,
> some will use them, some won't. I think it's undesirable and
> unnecessary. You can hciattach from here and most will work just like
> that. Tighter integration or anything special, module specific on top
> should be handled individially, on a case-by-case basis. This is a dev
> board after all. I say trick of all trades.

Changing to status=okay for sdmmc2 and uart8 should be fine, it does not
cause any issue for my pcie wifi module testing with a Radxa A8 module.

Testing with a Radxa A2 module (sdio+uart), the sdio/wifi part is
automatically discovered, however bluetooth require a DT overlay for
automatic probe. Something like this seem to work:

diff --git a/rk3568-rock-3b-radxa-a2.dtso b/rk3568-rock-3b-radxa-a2.dtso
new file mode 100644
index 000000000000..746b04e601af
--- /dev/null
+++ b/dts/rk3568-rock-3b-radxa-a2.dtso
@@ -0,0 +1,46 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+/*
+ * DT-overlay for Radxa ROCK Pi Wireless Module A2.
+ */
+
+/dts-v1/;
+/plugin/;
+
+#include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/interrupt-controller/irq.h>
+#include <dt-bindings/pinctrl/rockchip.h>
+
+&sdmmc2 {
+	#address-cells = <1>;
+	#size-cells = <0>;
+	status = "okay";
+
+	wifi at 1 {
+		compatible = "brcm,bcm43456-fmac", "brcm,bcm4329-fmac";
+		reg = <1>;
+		interrupt-parent = <&gpio0>;
+		interrupts = <RK_PD6 IRQ_TYPE_LEVEL_HIGH>;
+		interrupt-names = "host-wake";
+		pinctrl-names = "default";
+		pinctrl-0 = <&wifi_wake_host_h>;
+	};
+};
+
+&uart8 {
+	status = "okay";
+
+	bluetooth {
+		compatible = "brcm,bcm4345c5";
+		clocks = <&rk809 1>;
+		clock-names = "lpo";
+		interrupt-parent = <&gpio4>;
+		interrupts = <RK_PB5 IRQ_TYPE_LEVEL_HIGH>;
+		interrupt-names = "host-wakeup";
+		device-wakeup-gpios = <&gpio4 RK_PB4 GPIO_ACTIVE_HIGH>;
+		shutdown-gpios = <&gpio4 RK_PB2 GPIO_ACTIVE_HIGH>;
+		pinctrl-names = "default";
+		pinctrl-0 = <&bt_reg_on_h &bt_wake_host_h &host_wake_bt_h>;
+		vbat-supply = <&vcc3v3_sys2>;
+		vddio-supply = <&vcc_1v8>;
+	};
+};

With that applied wifi and bt module is detected and firmware loaded
during startup:

[    4.684687] mmc_host mmc2: Bus speed (slot 0) = 150000000Hz (slot req 150000000Hz, actual 150000000HZ div = 0)
[    4.699412] dwmmc_rockchip fe000000.mmc: Successfully tuned phase to 360
[    4.707429] mmc2: new ultra high speed SDR104 SDIO card at address 0001
[    4.717034] brcmfmac: brcmf_fw_alloc_request: using brcm/brcmfmac43456-sdio for chip BCM4345/9
[    4.760907] Bluetooth: hci0: BCM: chip id 130
[    4.763736] Bluetooth: hci0: BCM: features 0x0f
[    4.787714] Bluetooth: hci0: BCM4345C5
[    4.788482] Bluetooth: hci0: BCM4345C5 (003.006.006) build 0000
[   11.417553] Bluetooth: hci0: BCM: features 0x0f
[   11.441621] Bluetooth: hci0: BCM4345C5 Ampak_CL1 UART 37.4 MHz BT 5.2 [Version: 1039.1086]
[   11.442423] Bluetooth: hci0: BCM4345C5 (003.006.006) build 1086

Regards,
Jonas

> 
>> nasty looking error messages in the kernel log when there's actually
>> nothing connected to the UART.
> 
> My dmesg is clean as a whistle
> root at rock-3b:~# dmesg | grep -E 'fe6c0000|ttyS0'
> [    0.344818] fe6c0000.serial: ttyS0 at MMIO 0xfe6c0000 (irq = 26,
> base_baud = 1500000) is a 16550A
> What kind of nasty errors do you recall?
> 
> Kind regards,
> Tamas