Re: [PATCH] dt-bindings: clock: brcm,kona-ccu: convert to YAML
From: Stanislav Jakubek
Date: Mon Oct 23 2023 - 16:17:31 EST
On Mon, Oct 23, 2023 at 09:54:49AM +0200, Krzysztof Kozlowski wrote:
> On 22/10/2023 13:31, Stanislav Jakubek wrote:
> > Convert Broadcom Kona family clock controller unit (CCU) bindings
> > to DT schema.
> >
> > Signed-off-by: Stanislav Jakubek <stano.jakubek@xxxxxxxxx>
>
> Thank you for your patch. There is something to discuss/improve.
>
> > +description:
> > + Broadcom "Kona" style clock control unit (CCU) is a clock provider that
> > + manages a set of clock signals.
> > +
> > +properties:
> > + compatible:
> > + enum:
> > + - brcm,bcm11351-aon-ccu
> > + - brcm,bcm11351-hub-ccu
> > + - brcm,bcm11351-master-ccu
> > + - brcm,bcm11351-root-ccu
> > + - brcm,bcm11351-slave-ccu
> > + - brcm,bcm21664-aon-ccu
> > + - brcm,bcm21664-master-ccu
> > + - brcm,bcm21664-root-ccu
> > + - brcm,bcm21664-slave-ccu
> > +
> > + reg:
> > + maxItems: 1
> > +
> > + '#clock-cells':
> > + const: 1
> > +
> > + clock-output-names:
> > + minItems: 1
> > + maxItems: 10
> > +
> > +allOf:
> > + - if:
> > + properties:
> > + compatible:
> > + contains:
> > + enum:
> > + - brcm,bcm11351-aon-ccu
> > + - brcm,bcm11351-hub-ccu
> > + - brcm,bcm11351-master-ccu
> > + - brcm,bcm11351-root-ccu
> > + - brcm,bcm11351-slave-ccu
> > + then:
> > + properties:
> > + clock-output-names:
> > + description: |
> > + The following table defines the set of CCUs and clock specifiers
> > + for BCM281XX family clocks.
> > + These clock specifiers are defined in:
> > + "include/dt-bindings/clock/bcm281xx.h"
> > +
> > + CCU Clock Type Index Specifier
> > + --- ----- ---- ----- ---------
> > + root frac_1m peri 0 BCM281XX_ROOT_CCU_FRAC_1M
> > +
> > + aon hub_timer peri 0 BCM281XX_AON_CCU_HUB_TIMER
> > + aon pmu_bsc peri 1 BCM281XX_AON_CCU_PMU_BSC
> > + aon pmu_bsc_var peri 2 BCM281XX_AON_CCU_PMU_BSC_VAR
> > +
> > + hub tmon_1m peri 0 BCM281XX_HUB_CCU_TMON_1M
> > +
> > + master sdio1 peri 0 BCM281XX_MASTER_CCU_SDIO1
> > + master sdio2 peri 1 BCM281XX_MASTER_CCU_SDIO2
> > + master sdio3 peri 2 BCM281XX_MASTER_CCU_SDIO3
> > + master sdio4 peri 3 BCM281XX_MASTER_CCU_SDIO4
> > + master dmac peri 4 BCM281XX_MASTER_CCU_DMAC
> > + master usb_ic peri 5 BCM281XX_MASTER_CCU_USB_IC
> > + master hsic2_48m peri 6 BCM281XX_MASTER_CCU_HSIC_48M
> > + master hsic2_12m peri 7 BCM281XX_MASTER_CCU_HSIC_12M
> > +
> > + slave uartb peri 0 BCM281XX_SLAVE_CCU_UARTB
> > + slave uartb2 peri 1 BCM281XX_SLAVE_CCU_UARTB2
> > + slave uartb3 peri 2 BCM281XX_SLAVE_CCU_UARTB3
> > + slave uartb4 peri 3 BCM281XX_SLAVE_CCU_UARTB4
> > + slave ssp0 peri 4 BCM281XX_SLAVE_CCU_SSP0
> > + slave ssp2 peri 5 BCM281XX_SLAVE_CCU_SSP2
> > + slave bsc1 peri 6 BCM281XX_SLAVE_CCU_BSC1
> > + slave bsc2 peri 7 BCM281XX_SLAVE_CCU_BSC2
> > + slave bsc3 peri 8 BCM281XX_SLAVE_CCU_BSC3
> > + slave pwm peri 9 BCM281XX_SLAVE_CCU_PWM
>
> I don't really understand why this is in the binding schema. I guess you
> wanted to copy it from the old binding, but, unless there is real reason
> for it, don't. The clock IDs should be in the header file and that's it.
> Nothing here.
Hi Krzysztof, you're correct that I just copied this from the old bindings.
brcm,iproc-clocks.yaml has a similar table, so I thought this would be fine.
I'm OK with dropping it, but how should I document the clock-output-names
values then? A bunch of if-then blocks (per compatible)? Or should I not even
bother and just keep minItems/maxItems without documenting the values?
>
> > + - if:
> > + properties:
> > + compatible:
> > + contains:
> > + enum:
> > + - brcm,bcm21664-aon-ccu
> > + - brcm,bcm21664-master-ccu
> > + - brcm,bcm21664-root-ccu
> > + - brcm,bcm21664-slave-ccu
> > + then:
> > + properties:
> > + clock-output-names:
> > + maxItems: 8
I've also noticed that dtbs_check gives out warnings(?) like this for
bcm21664 ccu nodes:
/arch/arm/boot/dts/broadcom/bcm21664-garnet.dtb:
root_ccu@35001000: clock-output-names: ['frac_1m'] is too short
from schema $id: http://devicetree.org/schemas/clock/brcm,kona-ccu.yaml#
and this maxItems:8 seems to me like the culprit (since the bcm11351 if-then
doesn't have that). Seems to me like it also overrides the minItems to be 8
as well. I don't understand why it would do that though.
I suppose just adding minItems: 1 would be the correct fix in this case?
> > + description: |
> > + The following table defines the set of CCUs and clock specifiers
> > + for BCM21664 family clocks.
> > + These clock specifiers are defined in:
> > + "include/dt-bindings/clock/bcm21664.h"
> > +
> > + CCU Clock Type Index Specifier
> > + --- ----- ---- ----- ---------
> > + root frac_1m peri 0 BCM21664_ROOT_CCU_FRAC_1M
> > +
> > + aon hub_timer peri 0 BCM21664_AON_CCU_HUB_TIMER
> > +
> > + master sdio1 peri 0 BCM21664_MASTER_CCU_SDIO1
> > + master sdio2 peri 1 BCM21664_MASTER_CCU_SDIO2
> > + master sdio3 peri 2 BCM21664_MASTER_CCU_SDIO3
> > + master sdio4 peri 3 BCM21664_MASTER_CCU_SDIO4
> > + master sdio1_sleep peri 4 BCM21664_MASTER_CCU_SDIO1_SLEEP
> > + master sdio2_sleep peri 5 BCM21664_MASTER_CCU_SDIO2_SLEEP
> > + master sdio3_sleep peri 6 BCM21664_MASTER_CCU_SDIO3_SLEEP
> > + master sdio4_sleep peri 7 BCM21664_MASTER_CCU_SDIO4_SLEEP
> > +
> > + slave uartb peri 0 BCM21664_SLAVE_CCU_UARTB
> > + slave uartb2 peri 1 BCM21664_SLAVE_CCU_UARTB2
> > + slave uartb3 peri 2 BCM21664_SLAVE_CCU_UARTB3
> > + slave uartb4 peri 3 BCM21664_SLAVE_CCU_UARTB4
> > + slave bsc1 peri 4 BCM21664_SLAVE_CCU_BSC1
> > + slave bsc2 peri 5 BCM21664_SLAVE_CCU_BSC2
> > + slave bsc3 peri 6 BCM21664_SLAVE_CCU_BSC3
> > + slave bsc4 peri 7 BCM21664_SLAVE_CCU_BSC4
>
> Same comments.
>
> In any case, allOf: goes after required: block.
Ack.
>
> > +
> > +required:
> > + - compatible
> > + - reg
> > + - '#clock-cells'
> > + - clock-output-names
> > +
> > +additionalProperties: false
> > +
> Best regards,
> Krzysztof
>
Thanks for the feedback,
Stanislav