summaryrefslogtreecommitdiff
path: root/Documentation/devicetree/bindings/usb
diff options
context:
space:
mode:
authorAdam Wallis <awallis@codeaurora.org>2017-12-08 17:59:13 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-12-08 17:43:52 +0100
commitab725cbec3e83dc29cc00b733bd26063b588fa98 (patch)
tree9466ec276003810875ae7e896031c038ed8a8fff /Documentation/devicetree/bindings/usb
parent3054ea45fb8758b7c1a4849001e213e1267452fa (diff)
usb: xhci: allow imod-interval to be configurable
The xHCI driver currently has the IMOD set to 160, which translates to an IMOD interval of 40,000ns (160 * 250)ns Commit 0cbd4b34cda9 ("xhci: mediatek: support MTK xHCI host controller") introduced a QUIRK for the MTK platform to adjust this interval to 20, which translates to an IMOD interval of 5,000ns (20 * 250)ns. This is due to the fact that the MTK controller IMOD interval is 8 times as much as defined in xHCI spec. Instead of adding more quirk bits for additional platforms, this patch introduces the ability for vendors to set the IMOD_INTERVAL as is optimal for their platform. By using device_property_read_u32() on "imod-interval-ns", the IMOD INTERVAL can be specified in nano seconds. If no interval is specified, the default of 40,000ns (IMOD=160) will be used. No bounds checking has been implemented due to the fact that a vendor may have violated the spec and would need to specify a value outside of the max 8,000 IRQs/second limit specified in the xHCI spec. Tested-by: Chunfeng Yun <chunfeng.yun@mediatek.com> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Adam Wallis <awallis@codeaurora.org> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation/devicetree/bindings/usb')
-rw-r--r--Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.txt2
-rw-r--r--Documentation/devicetree/bindings/usb/usb-xhci.txt1
2 files changed, 3 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.txt b/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.txt
index 30595964876a..9ff560298498 100644
--- a/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.txt
+++ b/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.txt
@@ -46,6 +46,7 @@ Optional properties:
- pinctrl-names : a pinctrl state named "default" must be defined
- pinctrl-0 : pin control group
See: Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
+ - imod-interval-ns: default interrupt moderation interval is 5000ns
Example:
usb30: usb@11270000 {
@@ -66,6 +67,7 @@ usb30: usb@11270000 {
usb3-lpm-capable;
mediatek,syscon-wakeup = <&pericfg>;
mediatek,wakeup-src = <1>;
+ imod-interval-ns = <10000>;
};
2nd: dual-role mode with xHCI driver
diff --git a/Documentation/devicetree/bindings/usb/usb-xhci.txt b/Documentation/devicetree/bindings/usb/usb-xhci.txt
index a53107132cc3..e2ea59bbca93 100644
--- a/Documentation/devicetree/bindings/usb/usb-xhci.txt
+++ b/Documentation/devicetree/bindings/usb/usb-xhci.txt
@@ -31,6 +31,7 @@ Optional properties:
- usb2-lpm-disable: indicate if we don't want to enable USB2 HW LPM
- usb3-lpm-capable: determines if platform is USB3 LPM capable
- quirk-broken-port-ped: set if the controller has broken port disable mechanism
+ - imod-interval-ns: default interrupt moderation interval is 5000ns
Example:
usb@f0931000 {