Thread (8 messages) 8 messages, 2 authors, 2015-08-07

[PATCH v4 2/5] dt-bindings: Add a binding for Mediatek xHCI host controller

From: chunfeng.yun@mediatek.com (chunfeng yun)
Date: 2015-08-07 11:17:50
Also in: linux-devicetree, linux-mediatek, lkml

hi,

On Fri, 2015-07-31 at 14:45 +0100, Mark Rutland wrote:
Hi,

Sorry for my late reply to a prior version of this series, but I still
have concerns with some of the properties.

I'll repeat those below.

On Fri, Jul 31, 2015 at 02:03:53PM +0100, Chunfeng Yun wrote:
quoted
add a DT binding documentation of xHCI host controller for the
MT8173 SoC from Mediatek.

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
---
 .../devicetree/bindings/usb/mt8173-xhci.txt        | 51 ++++++++++++++++++++++
 1 file changed, 51 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/usb/mt8173-xhci.txt
diff --git a/Documentation/devicetree/bindings/usb/mt8173-xhci.txt b/Documentation/devicetree/bindings/usb/mt8173-xhci.txt
new file mode 100644
index 0000000..364be5a
--- /dev/null
+++ b/Documentation/devicetree/bindings/usb/mt8173-xhci.txt
@@ -0,0 +1,51 @@
+MT65XX xhci
+
+The device node for Mediatek SOC usb3.0 host controller
+
+Required properties:
+ - compatible : Supports "mediatek,mt8173-xhci"
s/Supports/should contain/
done
quoted
+ - reg : Specifies physical base address and size of the registers,
+	the first one for MAC, the second for IPPC
+ - interrupts : Interrupt mode, number and trigger mode
Just specify what this logically corresponds to; the format of the
interrupts proeprty depends on the interrupt controller.
done
quoted
+ - power-domains : To enable usb's mtcmos
Please describe what this contains. I assume you exped a single power
domain to be described, covering the whole xHCI controller?
quoted
+ - vusb33-supply : Regulator of usb avdd3.3v
+ - clocks : Must support all clocks that xhci needs
- clocks: a list of phandle + clock-specifier pairs, one for each entry
  in clock-names.
quoted
+ - clock-names : Should be "sys_mac" for sys and mac clocks, and
+	"wakeup_deb_p0", "wakeup_deb_p1" for wakeup debounce control
+	clocks
This would be better as a list, e.g.

- clock-names: should contain:
  * "sys_mac" <description here if necessary>
  * "wakeup_deb_p0" <description here if necessary>
  * "wakeup_deb_p1" <description here if necessary>
done
Is sys_mac a single clock input line? Or is it jsut the case that a
single line feeds two inputs currently? if the latter they should be
separate entries.
It is a single clock for usb MAC, already rename it
quoted
+ - phys : List of PHY specifiers (used by generic PHY framework).
The bracketed part should go. The bidnigns should know nothing of Linux
internals.
remove it
quoted
+ - phy-names : Must be "usb-phy0", "usb-phy1",.., "usb-phyN", based on
+	the number of PHYs as specified in @phys property.
This is useless.

You either don't need names, and can acquire the phys by index, or you
need names which correspond to those on the data sheet for the xHCI
controller.
Ok, re-write the phy driver, and here also make use of the new format.
quoted
+ - mediatek,usb-wakeup : To access usb wakeup control register
Please describe what this points to (I guess it's a syscon)/
quoted
+ - mediatek,wakeup-src : 1: Ip sleep wakeup mode; 2: line state wakeup
+	mode; others means don't enable wakeup source of usb
This sounds like a runtime decision.
No, the driver do not know whether to enable wakeup function or not and
also don't know enable which one, except tell it. 
And it will set different registers of @mediatek,usb-wakeup to enable
the selected wakeup mode when system enter suspend.
_why_ do you think this needs to be in the DT?
quoted
+ - mediatek,u2port-num : The number should not greater than the number
+	of phys
This is useless. Either this is implied by the entries in the phys
property, or it should be a runtime decision.
Yes, it can be calculated from @phys, already remove it.

Thanks a lot for your suggestion
 
Thanks,
Mark.
quoted
+
+Optional properties:
+ - vbus-supply : Reference to the VBUS regulator;
+
+Example:
+usb: usb at 11270000 {
+	compatible = "mediatek,mt8173-xhci";
+	reg = <0 0x11270000 0 0x4000>,
+	      <0 0x11280000 0 0x0800>;
+	interrupts = <GIC_SPI 115 IRQ_TYPE_LEVEL_LOW>;
+	power-domains = <&scpsys MT8173_POWER_DOMAIN_USB>;
+	clocks = <&topckgen CLK_TOP_USB30_SEL>,
+		 <&pericfg CLK_PERI_USB0>,
+		 <&pericfg CLK_PERI_USB1>;
+	clock-names = "sys_mac",
+		      "wakeup_deb_p0",
+		      "wakeup_deb_p1";
+	phys = <&u3phy 0>, <&u3phy 1>;
+	phy-names = "usb-phy0", "usb-phy1";
+	vusb33-supply = <&mt6397_vusb_reg>;
+	vbus-supply = <&usb_p1_vbus>;
+	usb3-lpm-capable;
+	mediatek,usb-wakeup = <&pericfg>;
+	mediatek,wakeup-src = <1>;
+	mediatek,u2port-num = <2>;
+	status = "okay";
+};
-- 
1.8.1.1.dirty
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