Re: [PATCH] ARM: dts: at91: sam9x60: fix the SOC detection

From: Alexandre Belloni
Date: Wed Jul 12 2023 - 16:04:59 EST

On 12/07/2023 20:42:00+0100, Conor Dooley wrote:
> > There can be only one dbgu on a SoC and it has the chipid register. It
> > has always been wrong to have a dbgu compatible on the flexcom uart as
> > they are not dbgu.
>
> Ahh, thanks for the explanation. Sounds like stuff that might be obvious
> to those working on arm stuff all the time, but not all of those CCed on
> the patch ;)

Well, this is not really arm specific, rather microchip specific ;)

> The correct thing to do would seem to be updating the dt-binding to
> something that permits what is listed below, or just removing the second
> compatible, to leave "microchip,sam9x60-usart" in isolation, since that
> is permitted also.
>
> > Anyway, my advice has always been that you must not do chipid detection
> > on at91 because there is no point in doing it because you need to have
> > a correct dts to be able to find the dbgu chipid register so you either
> > you already know what you are running on or you are going to read bogus
> > registers anyway.
>
> I won't claim to have an opinion on any of that, but sounds like you'd
> be better off just reading the board/SoC level compatibles to figure out
> what you are running on...
>

Yeah, exactly my point!

> Thanks,
> Conor.
>
> > > > Fixes: 99c808335877 (ARM: dts: at91: sam9x60: Add missing flexcom definitions)
> > > > Signed-off-by: Durai Manickam KR <durai.manickamkr@xxxxxxxxxxxxx>
> > > > ---
> > > > arch/arm/boot/dts/microchip/sam9x60.dtsi | 26 ++++++++++++------------
> > > > 1 file changed, 13 insertions(+), 13 deletions(-)
> > > >
> > > > diff --git a/arch/arm/boot/dts/microchip/sam9x60.dtsi b/arch/arm/boot/dts/microchip/sam9x60.dtsi
> > > > index 8b53997675e7..73d570a17269 100644
> > > > --- a/arch/arm/boot/dts/microchip/sam9x60.dtsi
> > > > +++ b/arch/arm/boot/dts/microchip/sam9x60.dtsi
> > > > @@ -172,7 +172,7 @@ flx4: flexcom@f0000000 {
> > > > status = "disabled";
> > > >
> > > > uart4: serial@200 {
> > > > - compatible = "microchip,sam9x60-dbgu", "microchip,sam9x60-usart", "atmel,at91sam9260-dbgu", "atmel,at91sam9260-usart";
> > > > + compatible = "microchip,sam9x60-usart", "atmel,at91sam9260-usart";
> > > > reg = <0x200 0x200>;
> > > > interrupts = <13 IRQ_TYPE_LEVEL_HIGH 7>;
> > > > dmas = <&dma0
> > > > @@ -240,7 +240,7 @@ flx5: flexcom@f0004000 {
> > > > status = "disabled";
> > > >
> > > > uart5: serial@200 {
> > > > - compatible = "microchip,sam9x60-dbgu", "microchip,sam9x60-usart", "atmel,at91sam9260-dbgu", "atmel,at91sam9260-usart";
> > > > + compatible = "microchip,sam9x60-usart", "atmel,at91sam9260-usart";
> > > > reg = <0x200 0x200>;
> > > > atmel,usart-mode = <AT91_USART_MODE_SERIAL>;
> > > > interrupts = <14 IRQ_TYPE_LEVEL_HIGH 7>;
> > > > @@ -370,7 +370,7 @@ flx11: flexcom@f0020000 {
> > > > status = "disabled";
> > > >
> > > > uart11: serial@200 {
> > > > - compatible = "microchip,sam9x60-dbgu", "microchip,sam9x60-usart", "atmel,at91sam9260-dbgu", "atmel,at91sam9260-usart";
> > > > + compatible = "microchip,sam9x60-usart", "atmel,at91sam9260-usart";
> > > > reg = <0x200 0x200>;
> > > > interrupts = <32 IRQ_TYPE_LEVEL_HIGH 7>;
> > > > dmas = <&dma0
> > > > @@ -419,7 +419,7 @@ flx12: flexcom@f0024000 {
> > > > status = "disabled";
> > > >
> > > > uart12: serial@200 {
> > > > - compatible = "microchip,sam9x60-dbgu", "microchip,sam9x60-usart", "atmel,at91sam9260-dbgu", "atmel,at91sam9260-usart";
> > > > + compatible = "microchip,sam9x60-usart", "atmel,at91sam9260-usart";
> > > > reg = <0x200 0x200>;
> > > > interrupts = <33 IRQ_TYPE_LEVEL_HIGH 7>;
> > > > dmas = <&dma0
> > > > @@ -576,7 +576,7 @@ flx6: flexcom@f8010000 {
> > > > status = "disabled";
> > > >
> > > > uart6: serial@200 {
> > > > - compatible = "microchip,sam9x60-dbgu", "microchip,sam9x60-usart", "atmel,at91sam9260-dbgu", "atmel,at91sam9260-usart";
> > > > + compatible = "microchip,sam9x60-usart", "atmel,at91sam9260-usart";
> > > > reg = <0x200 0x200>;
> > > > interrupts = <9 IRQ_TYPE_LEVEL_HIGH 7>;
> > > > dmas = <&dma0
> > > > @@ -625,7 +625,7 @@ flx7: flexcom@f8014000 {
> > > > status = "disabled";
> > > >
> > > > uart7: serial@200 {
> > > > - compatible = "microchip,sam9x60-dbgu", "microchip,sam9x60-usart", "atmel,at91sam9260-dbgu", "atmel,at91sam9260-usart";
> > > > + compatible = "microchip,sam9x60-usart", "atmel,at91sam9260-usart";
> > > > reg = <0x200 0x200>;
> > > > interrupts = <10 IRQ_TYPE_LEVEL_HIGH 7>;
> > > > dmas = <&dma0
> > > > @@ -674,7 +674,7 @@ flx8: flexcom@f8018000 {
> > > > status = "disabled";
> > > >
> > > > uart8: serial@200 {
> > > > - compatible = "microchip,sam9x60-dbgu", "microchip,sam9x60-usart", "atmel,at91sam9260-dbgu", "atmel,at91sam9260-usart";
> > > > + compatible = "microchip,sam9x60-usart", "atmel,at91sam9260-usart";
> > > > reg = <0x200 0x200>;
> > > > interrupts = <11 IRQ_TYPE_LEVEL_HIGH 7>;
> > > > dmas = <&dma0
> > > > @@ -723,7 +723,7 @@ flx0: flexcom@f801c000 {
> > > > status = "disabled";
> > > >
> > > > uart0: serial@200 {
> > > > - compatible = "microchip,sam9x60-dbgu", "microchip,sam9x60-usart", "atmel,at91sam9260-dbgu", "atmel,at91sam9260-usart";
> > > > + compatible = "microchip,sam9x60-usart", "atmel,at91sam9260-usart";
> > > > reg = <0x200 0x200>;
> > > > interrupts = <5 IRQ_TYPE_LEVEL_HIGH 7>;
> > > > dmas = <&dma0
> > > > @@ -791,7 +791,7 @@ flx1: flexcom@f8020000 {
> > > > status = "disabled";
> > > >
> > > > uart1: serial@200 {
> > > > - compatible = "microchip,sam9x60-dbgu", "microchip,sam9x60-usart", "atmel,at91sam9260-dbgu", "atmel,at91sam9260-usart";
> > > > + compatible = "microchip,sam9x60-usart", "atmel,at91sam9260-usart";
> > > > reg = <0x200 0x200>;
> > > > interrupts = <6 IRQ_TYPE_LEVEL_HIGH 7>;
> > > > dmas = <&dma0
> > > > @@ -859,7 +859,7 @@ flx2: flexcom@f8024000 {
> > > > status = "disabled";
> > > >
> > > > uart2: serial@200 {
> > > > - compatible = "microchip,sam9x60-dbgu", "microchip,sam9x60-usart", "atmel,at91sam9260-dbgu", "atmel,at91sam9260-usart";
> > > > + compatible = "microchip,sam9x60-usart", "atmel,at91sam9260-usart";
> > > > reg = <0x200 0x200>;
> > > > interrupts = <7 IRQ_TYPE_LEVEL_HIGH 7>;
> > > > dmas = <&dma0
> > > > @@ -927,7 +927,7 @@ flx3: flexcom@f8028000 {
> > > > status = "disabled";
> > > >
> > > > uart3: serial@200 {
> > > > - compatible = "microchip,sam9x60-dbgu", "microchip,sam9x60-usart", "atmel,at91sam9260-dbgu", "atmel,at91sam9260-usart";
> > > > + compatible = "microchip,sam9x60-usart", "atmel,at91sam9260-usart";
> > > > reg = <0x200 0x200>;
> > > > interrupts = <8 IRQ_TYPE_LEVEL_HIGH 7>;
> > > > dmas = <&dma0
> > > > @@ -1050,7 +1050,7 @@ flx9: flexcom@f8040000 {
> > > > status = "disabled";
> > > >
> > > > uart9: serial@200 {
> > > > - compatible = "microchip,sam9x60-dbgu", "microchip,sam9x60-usart", "atmel,at91sam9260-dbgu", "atmel,at91sam9260-usart";
> > > > + compatible = "microchip,sam9x60-usart", "atmel,at91sam9260-usart";
> > > > reg = <0x200 0x200>;
> > > > interrupts = <15 IRQ_TYPE_LEVEL_HIGH 7>;
> > > > dmas = <&dma0
> > > > @@ -1099,7 +1099,7 @@ flx10: flexcom@f8044000 {
> > > > status = "disabled";
> > > >
> > > > uart10: serial@200 {
> > > > - compatible = "microchip,sam9x60-dbgu", "microchip,sam9x60-usart", "atmel,at91sam9260-dbgu", "atmel,at91sam9260-usart";
> > > > + compatible = "microchip,sam9x60-usart", "atmel,at91sam9260-usart";
> > > > reg = <0x200 0x200>;
> > > > interrupts = <16 IRQ_TYPE_LEVEL_HIGH 7>;
> > > > dmas = <&dma0
> > > > --
> > > > 2.25.1
> > > >
> >
> >
> >
> > --
> > Alexandre Belloni, co-owner and COO, Bootlin
> > Embedded Linux and Kernel engineering
> > https://bootlin.com



--
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com