Referring to the note under USBH reset and clocks chapter of RM0436,
"In order to access USBH_OHCI registers it is necessary to activate the USB
clocks by enabling the PLL controlled by USBPHYC" (ck_usbo_48m).
The point is, when USBPHYC PLL is not enabled, OHCI register access
freezes the resume from STANDBY. It is the case when dual USBH is enabled,
instead of OTG + single USBH.
When OTG is probed, as ck_usbo_48m is USBO clock parent, then USBPHYC PLL
is enabled and OHCI register access is OK.
This patch adds ck_usbo_48m (provided by USBPHYC PLL) as clock of USBH
OHCI, thus USBPHYC PLL will be enabled and OHCI register access will be OK.
Signed-off-by: Amelie Delaunay <amelie.delaunay@xxxxxxxxxxx>
---
arch/arm/boot/dts/stm32mp151.dtsi | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm/boot/dts/stm32mp151.dtsi b/arch/arm/boot/dts/stm32mp151.dtsi
index bd289bf5d269..fe194c787e6c 100644
--- a/arch/arm/boot/dts/stm32mp151.dtsi
+++ b/arch/arm/boot/dts/stm32mp151.dtsi
@@ -1452,7 +1452,7 @@ stmmac_axi_config_0: stmmac-axi-config {
usbh_ohci: usb@5800c000 {
compatible = "generic-ohci";
reg = <0x5800c000 0x1000>;
- clocks = <&rcc USBH>;
+ clocks = <&rcc USBH>, <&usbphyc>;
resets = <&rcc USBH_R>;
interrupts = <GIC_SPI 74 IRQ_TYPE_LEVEL_HIGH>;
status = "disabled";
--
2.25.1
