Re: [PATCH 7/8] arm64: dts: rockchip: Add SDMMC/SDIO controllers for RK3528

Hi Heiko,

On 2025-03-01 13:55, Heiko Stübner wrote:

Hey Joas,

Am Samstag, 1. März 2025, 13:47:47 MEZ schrieb Jonas Karlman:

quoted

On 2025-03-01 11:47, Yao Zi wrote:

quoted

RK3528 features two SDIO controllers and one SD/MMC controller, describe
them in devicetree. Since their sample and drive clocks are located in
the VO and VPU GRFs, corresponding syscons are added to make these
clocks available.

Signed-off-by: Yao Zi <redacted>
---
 arch/arm64/boot/dts/rockchip/rk3528.dtsi | 62 ++++++++++++++++++++++++
 1 file changed, 62 insertions(+)

diff --git a/arch/arm64/boot/dts/rockchip/rk3528.dtsi b/arch/arm64/boot/dts/rockchip/rk3528.dtsi
index 5b334690356a..078c97fa1d9f 100644
--- a/arch/arm64/boot/dts/rockchip/rk3528.dtsi
+++ b/arch/arm64/boot/dts/rockchip/rk3528.dtsi

@@ -7,6 +7,7 @@
 #include <dt-bindings/interrupt-controller/arm-gic.h>
 #include <dt-bindings/interrupt-controller/irq.h>
 #include <dt-bindings/clock/rockchip,rk3528-cru.h>
+#include <dt-bindings/reset/rockchip,rk3528-cru.h>
 
 / {
 	compatible = "rockchip,rk3528";

@@ -122,6 +123,16 @@ gic: interrupt-controller@fed01000 {
 			#interrupt-cells = <3>;
 		};
 
+		vpu_grf: syscon@ff340000 {
+			compatible = "rockchip,rk3528-vpu-grf", "syscon";

vpu_grf is also used for gmac1, so should possible be a "syscon",
"simple-mfd", or have I misunderstood when to use simple-mfd ?

simple-mfd is needed when the additional device is completely contained
inside the particular syscon.

For example, the usb2phy0 on rk3588 is completely living inside the
usb2phy0-grf.

Similarly the power-domains are living inside the rk3588 pmugrf.
But the pmugrf also contains more stuff, so the power-domains are a
subset of the pmugrf.

Both of these above are a case for a simple-mfd.


Similarly, gmac1 on rk3588 is ethernet@fe1c0000 , so a completely separate
io-memory area, but references both the sysgrf as well as the php-grf
as syscons for additional settings.

So here the syscon does not need to be a simple-mfd.


Hope that helps a bit

Thanks for this explanation, it helped me better understand the meaning
of simple-mfd :-)

Regards,
Jonas

Heiko