linux/Documentation/devicetree/bindings/usb/ci-hdrc-usb2.txt
Peter Chen 4670ba6c9e doc: usb: ci-hdrc-usb2: add property non-zero-ttctrl-ttha
If this property is not set, the max packet size is 1023 bytes, and if
the total of packet size for pervious transactions are more than 256 bytes,
it can't accept any transactions within this frame. The use case is single
transaction, but higher frame rate.

If this property is set, the max packet size is 188 bytes, it can handle
more transactions than above case, it can accept transactions until it
considers the left room size within frame is less than 188 bytes, software
needs to make sure it does not send more than 90%
maximum_periodic_data_per_frame. The use case is multiple transactions, but
less frame rate.

Signed-off-by: Peter Chen <peter.chen@nxp.com>
2016-02-29 13:37:51 +08:00

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* USB2 ChipIdea USB controller for ci13xxx
Required properties:
- compatible: should be one of:
"fsl,imx23-usb"
"fsl,imx27-usb"
"fsl,imx28-usb"
"fsl,imx6q-usb"
"fsl,imx6sl-usb"
"fsl,imx6sx-usb"
"fsl,imx6ul-usb"
"fsl,imx7d-usb"
"lsi,zevio-usb"
"qcom,ci-hdrc"
"chipidea,usb2"
"xlnx,zynq-usb-2.20a"
- reg: base address and length of the registers
- interrupts: interrupt for the USB controller
Recommended properies:
- phy_type: the type of the phy connected to the core. Should be one
of "utmi", "utmi_wide", "ulpi", "serial" or "hsic". Without this
property the PORTSC register won't be touched.
- dr_mode: One of "host", "peripheral" or "otg". Defaults to "otg"
Deprecated properties:
- usb-phy: phandle for the PHY device. Use "phys" instead.
- fsl,usbphy: phandle of usb phy that connects to the port. Use "phys" instead.
Optional properties:
- clocks: reference to the USB clock
- phys: reference to the USB PHY
- phy-names: should be "usb-phy"
- vbus-supply: reference to the VBUS regulator
- maximum-speed: limit the maximum connection speed to "full-speed".
- tpl-support: TPL (Targeted Peripheral List) feature for targeted hosts
- itc-setting: interrupt threshold control register control, the setting
should be aligned with ITC bits at register USBCMD.
- ahb-burst-config: it is vendor dependent, the required value should be
aligned with AHBBRST at SBUSCFG, the range is from 0x0 to 0x7. This
property is used to change AHB burst configuration, check the chipidea
spec for meaning of each value. If this property is not existed, it
will use the reset value.
- tx-burst-size-dword: it is vendor dependent, the tx burst size in dword
(4 bytes), This register represents the maximum length of a the burst
in 32-bit words while moving data from system memory to the USB
bus, the value of this property will only take effect if property
"ahb-burst-config" is set to 0, if this property is missing the reset
default of the hardware implementation will be used.
- rx-burst-size-dword: it is vendor dependent, the rx burst size in dword
(4 bytes), This register represents the maximum length of a the burst
in 32-bit words while moving data from the USB bus to system memory,
the value of this property will only take effect if property
"ahb-burst-config" is set to 0, if this property is missing the reset
default of the hardware implementation will be used.
- extcon: phandles to external connector devices. First phandle should point to
external connector, which provide "USB" cable events, the second should point
to external connector device, which provide "USB-HOST" cable events. If one
of the external connector devices is not required, empty <0> phandle should
be specified.
- phy-clkgate-delay-us: the delay time (us) between putting the PHY into
low power mode and gating the PHY clock.
- non-zero-ttctrl-ttha: after setting this property, the value of register
ttctrl.ttha will be 0x7f; if not, the value will be 0x0, this is the default
value. It needs to be very carefully for setting this property, it is
recommended that consult with your IC engineer before setting this value.
On the most of chipidea platforms, the "usage_tt" flag at RTL is 0, so this
property only affects siTD.
If this property is not set, the max packet size is 1023 bytes, and if
the total of packet size for pervious transactions are more than 256 bytes,
it can't accept any transactions within this frame. The use case is single
transaction, but higher frame rate.
If this property is set, the max packet size is 188 bytes, it can handle
more transactions than above case, it can accept transactions until it
considers the left room size within frame is less than 188 bytes, software
needs to make sure it does not send more than 90%
maximum_periodic_data_per_frame. The use case is multiple transactions, but
less frame rate.
i.mx specific properties
- fsl,usbmisc: phandler of non-core register device, with one
argument that indicate usb controller index
- disable-over-current: disable over current detect
- external-vbus-divider: enables off-chip resistor divider for Vbus
Example:
usb@f7ed0000 {
compatible = "chipidea,usb2";
reg = <0xf7ed0000 0x10000>;
interrupts = <GIC_SPI 11 IRQ_TYPE_LEVEL_HIGH>;
clocks = <&chip CLKID_USB0>;
phys = <&usb_phy0>;
phy-names = "usb-phy";
vbus-supply = <&reg_usb0_vbus>;
gadget-itc-setting = <0x4>; /* 4 micro-frames */
/* Incremental burst of unspecified length */
ahb-burst-config = <0x0>;
tx-burst-size-dword = <0x10>; /* 64 bytes */
rx-burst-size-dword = <0x10>;
extcon = <0>, <&usb_id>;
phy-clkgate-delay-us = <400>;
};