On 20/03/2024 12:33, Caleb Connolly wrote:
On 19/03/2024 13:55, Sumit Garg wrote:
On Tue, 19 Mar 2024 at 17:52, Caleb Connolly caleb.connolly@linaro.org wrote:
The USB VBUS supply for the type-A port is enabled via a GPIO regulator. This is incorrectly modelled in Linux where only the PCIe dependency is expressed.
Can we send a fix for the Linux kernel DTS to correctly model it? We can then later get rid of this modification once that is accepted.
I spoke to Bjorn about this and apparently the correct way to model this will be to have a usb-connector node with a vbus-supply property. There is some work underway in Linux to support this kind of thing already.
In the mean time he suggested to just make the regulator always-on, so I sent a patch to do that [1]. I actually hit this issue when booting from USB as the PCIe drivers aren't available in the initramfs, so USB never turns on, and the always-on hack fixes that.
In the mean time, we'll still need this vbus-supply reference as U-Boot doesn't automatically probe regulators.
oh, forgot the link!
[1]: https://lore.kernel.org/linux-arm-msm/20240320122515.3243711-1-caleb.connoll...
-Sumit
Add a U-Boot specific dtsi snippet so that this supply will get enabled when initialising USB.
Signed-off-by: Caleb Connolly caleb.connolly@linaro.org
arch/arm/dts/sdm845-db845c-u-boot.dtsi | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/arch/arm/dts/sdm845-db845c-u-boot.dtsi b/arch/arm/dts/sdm845-db845c-u-boot.dtsi new file mode 100644 index 000000000000..3c83e21251c4 --- /dev/null +++ b/arch/arm/dts/sdm845-db845c-u-boot.dtsi @@ -0,0 +1,8 @@ +// SPDX-License-Identifier: GPL-2.0
+/* This GPIO must be turned on to enable the 5v VBUS
- supply on the USB port.
- */
+&usb_2_dwc3 {
vbus-supply = <&pcie0_3p3v_dual>;+};
-- 2.44.0