| Message ID | 20220411121108.63436-1-matthias.schiffer@ew.tq-group.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: dts: ti: k3-am64-mcu: explicitly assign UART base clock rates | expand |
On 11/04/22 5:41 pm, Matthias Schiffer wrote: > We found that (at least some versions of) the sci-fw do not assign the > expected base clock rate of 48 MHz for the UARTs in the MCU domain, > leading to incorrect baud rates when used from Linux. Use > assigned-clock-rates to fix this issue. > > Fixes: 8abae9389bdb ("arm64: dts: ti: Add support for AM642 SoC") > Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com> > --- > > I'm not sure if this is the best fix. Should the clock-frequency > property simply be removed, so the frequency is queried from the clock > driver instead? > I think its better to drop clock-frequency. Driver can setup DLL/DLH to get appropriate baudrate as per frequency queried from clock driver > arch/arm64/boot/dts/ti/k3-am64-mcu.dtsi | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/arch/arm64/boot/dts/ti/k3-am64-mcu.dtsi b/arch/arm64/boot/dts/ti/k3-am64-mcu.dtsi > index 2bb5c9ff172c..69b0f127eea5 100644 > --- a/arch/arm64/boot/dts/ti/k3-am64-mcu.dtsi > +++ b/arch/arm64/boot/dts/ti/k3-am64-mcu.dtsi > @@ -15,6 +15,8 @@ mcu_uart0: serial@4a00000 { > power-domains = <&k3_pds 149 TI_SCI_PD_EXCLUSIVE>; > clocks = <&k3_clks 149 0>; > clock-names = "fclk"; > + assigned-clocks = <&k3_clks 149 0>; > + assigned-clock-rates = <48000000>; > }; > > mcu_uart1: serial@4a10000 { > @@ -26,6 +28,8 @@ mcu_uart1: serial@4a10000 { > power-domains = <&k3_pds 160 TI_SCI_PD_EXCLUSIVE>; > clocks = <&k3_clks 160 0>; > clock-names = "fclk"; > + assigned-clocks = <&k3_clks 160 0>; > + assigned-clock-rates = <48000000>; > }; > > mcu_i2c0: i2c@4900000 {
diff --git a/arch/arm64/boot/dts/ti/k3-am64-mcu.dtsi b/arch/arm64/boot/dts/ti/k3-am64-mcu.dtsi index 2bb5c9ff172c..69b0f127eea5 100644 --- a/arch/arm64/boot/dts/ti/k3-am64-mcu.dtsi +++ b/arch/arm64/boot/dts/ti/k3-am64-mcu.dtsi @@ -15,6 +15,8 @@ mcu_uart0: serial@4a00000 { power-domains = <&k3_pds 149 TI_SCI_PD_EXCLUSIVE>; clocks = <&k3_clks 149 0>; clock-names = "fclk"; + assigned-clocks = <&k3_clks 149 0>; + assigned-clock-rates = <48000000>; }; mcu_uart1: serial@4a10000 { @@ -26,6 +28,8 @@ mcu_uart1: serial@4a10000 { power-domains = <&k3_pds 160 TI_SCI_PD_EXCLUSIVE>; clocks = <&k3_clks 160 0>; clock-names = "fclk"; + assigned-clocks = <&k3_clks 160 0>; + assigned-clock-rates = <48000000>; }; mcu_i2c0: i2c@4900000 {
We found that (at least some versions of) the sci-fw do not assign the expected base clock rate of 48 MHz for the UARTs in the MCU domain, leading to incorrect baud rates when used from Linux. Use assigned-clock-rates to fix this issue. Fixes: 8abae9389bdb ("arm64: dts: ti: Add support for AM642 SoC") Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com> --- I'm not sure if this is the best fix. Should the clock-frequency property simply be removed, so the frequency is queried from the clock driver instead? arch/arm64/boot/dts/ti/k3-am64-mcu.dtsi | 4 ++++ 1 file changed, 4 insertions(+)