On 11/02/2025 06:15, Haylen Chu wrote: > On Sat, Jan 04, 2025 at 11:07:58AM +0100, Krzysztof Kozlowski wrote: >> On Fri, Jan 03, 2025 at 09:56:35PM +0000, Haylen Chu wrote: >>> Add documentation to describe Spacemit K1 system controller registers. >>> >>> Signed-off-by: Haylen Chu <heylenay@xxxxxxx> >>> --- >>> .../soc/spacemit/spacemit,k1-syscon.yaml | 52 +++++++++++++++++++ >>> 1 file changed, 52 insertions(+) >>> create mode 100644 Documentation/devicetree/bindings/soc/spacemit/spacemit,k1-syscon.yaml >>> >>> diff --git a/Documentation/devicetree/bindings/soc/spacemit/spacemit,k1-syscon.yaml b/Documentation/devicetree/bindings/soc/spacemit/spacemit,k1-syscon.yaml >>> new file mode 100644 >>> index 000000000000..79c4a74ff30e >>> --- /dev/null >>> +++ b/Documentation/devicetree/bindings/soc/spacemit/spacemit,k1-syscon.yaml >>> @@ -0,0 +1,52 @@ >>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) >>> +%YAML 1.2 >>> +--- >>> +$id: http://devicetree.org/schemas/soc/spacemit/spacemit,k1-syscon.yaml# >>> +$schema: http://devicetree.org/meta-schemas/core.yaml# >>> + >>> +title: Spacemit K1 SoC System Controller >>> + >>> +maintainers: >>> + - Haylen Chu <heylenay@xxxxxxx> >>> + >>> +description: >>> + The Spacemit K1 SoC system controller provides access to shared register files >>> + for related SoC modules, such as clock controller and reset controller. >>> + >>> +properties: >>> + compatible: >>> + items: >>> + - enum: >>> + - spacemit,k1-apbc-syscon >>> + - spacemit,k1-apbs-syscon >>> + - spacemit,k1-apmu-syscon >>> + - spacemit,k1-mpmu-syscon >>> + - const: syscon >>> + - const: simple-mfd >>> + >>> + reg: >>> + maxItems: 1 >>> + >>> + clock-controller: >>> + $ref: /schemas/clock/spacemit,k1-ccu.yaml# >>> + type: object >> >> So now we see the full picture and it leads to questions. >> >> 1. Why spacemit,k1-apbc-syscon with spacemit,k1-ccu-apmu child is a >> correct combination? >> >> 2. Why having this split in the first place? Please confirm that clock >> controller is really, really a separate device and its child in >> datasheet. IOW, fake child for your Linux is a no-go. Fake child while >> devices are independent is another no-go. > > These syscons are introduced because the clock controllers share > registers with reset controllers. Folding them into the parents results So a fake split... > in devicetree nodes act as both reset and clock controllers, like what Which is correct hardware representation, isn't it? > has been done for Rockchip SoCs. Such folding isn't practical for the > MPMU region either, since watchdog and other misc bits (e.g. PLL lock > status) locates in it. Hm? Why? You have a device which is reset and clock controller, so why one device node is not practical? Other vendors do not have problem with this. > > If you're more comfortable with reset and clock controllers folded > together and eliminating most of these syscons, I'm willing to make the > change. This is expected. Best regards, Krzysztof
