Re: [PATCH 2/7] dt-bindings: mmc: Add Actions Semi SD/MMC/SDIO controller binding

On Mon, Jun 10, 2019 at 03:45:37PM +0200, Andreas Färber wrote:

Am 08.06.19 um 21:53 schrieb Manivannan Sadhasivam:

quoted

Add devicetree binding for Actions Semi Owl SoC's SD/MMC/SDIO controller.

Signed-off-by: Manivannan Sadhasivam <redacted>
---
 .../devicetree/bindings/mmc/owl-mmc.txt       | 37 +++++++++++++++++++
 1 file changed, 37 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mmc/owl-mmc.txt

Rob, should this be YAML now?

Would be nice and might get reviewed faster, but I'll leave that to Ulf 
to start requiring.

quoted

diff --git a/Documentation/devicetree/bindings/mmc/owl-mmc.txt b/Documentation/devicetree/bindings/mmc/owl-mmc.txt
new file mode 100644
index 000000000000..a702f8d66cec
--- /dev/null
+++ b/Documentation/devicetree/bindings/mmc/owl-mmc.txt

@@ -0,0 +1,37 @@
+Actions Semi Owl SoCs SD/MMC/SDIO controller
+
+Required properties:
+- compatible: should be "actions,owl-mmc"
+- reg: offset and length of the register set for the device.
+- interrupts: single interrupt specifier.
+- clocks: single clock specifier of the controller clock.
+- resets: phandle to the reset line.
+- dma-names: should be "mmc".
+- dmas: single DMA channel specifier

I recall the main blocker for MMC being regulators, i.e. the I²C
attached multi-function PMIC. Yet I don't see any such required property
here, nor any patch series implementing it. Seems like this relies on
U-Boot having initialized SD/eMMC? Do you intend to make them optional
or did you want to hold off merging this one until the rest is done?

quoted

+
+Optional properties:
+- pinctrl-names: pinctrl state names "default" must be defined.
+- pinctrl-0: phandle referencing pin configuration of the controller.
+- bus-width: see mmc.txt
+- cap-sd-highspeed: see mmc.txt
+- cap-mmc-highspeed: see mmc.txt
+- sd-uhs-sdr12: see mmc.txt
+- sd-uhs-sdr25: see mmc.txt
+- sd-uhs-sdr50: see mmc.txt
+- non-removable: see mmc.txt

I'm not convinced duplicating common properties is a good idea here, in
particular pinctrl.

The main value is to define which common properties are valid for this 
binding (and by omission which ones aren't valid).

Rob