Re: [PATCH v4 10/18] dt-bindings: usb: Convert DWC USB3 bindings to DT schema

Rob Herring
2020-11-11T20:14:34Z

On Wed, Nov 11, 2020 at 12:08:45PM +0300, Serge Semin wrote:
> DWC USB3 DT node is supposed to be compliant with the Generic xHCI
> Controller schema, but with additional vendor-specific properties, the
> controller-specific reference clocks and PHYs. So let's convert the
> currently available legacy text-based DWC USB3 bindings to the DT schema
> and make sure the DWC USB3 nodes are also validated against the
> usb-xhci.yaml schema.
>
> Note we have to discard the nodename restriction of being prefixed with
> "dwc3@" string, since in accordance with the usb-hcd.yaml schema USB nodes
> are supposed to be named as "^usb(@.*)".
>
> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
>
> ---
>
> Changelog v2:
> - Discard '|' from the descriptions, since we don't need to preserve
> the text formatting in any of them.
> - Drop quotes from around the string constants.
> - Fix the "clock-names" prop description to be referring the enumerated
> clock-names instead of the ones from the Databook.
>
> Changelog v3:
> - Apply usb-xhci.yaml# schema only if the controller is supposed to work
> as either host or otg.
>
> Changelog v4:
> - Apply usb-drd.yaml schema first. If the controller is configured
> to work in a gadget mode only, then apply the usb.yaml schema too,
> otherwise apply the usb-xhci.yaml schema.
> - Discard the Rob'es Reviewed-by tag. Please review the patch one more
> time.
> ---
> .../devicetree/bindings/usb/dwc3.txt | 125 --------
> .../devicetree/bindings/usb/snps,dwc3.yaml | 303 ++++++++++++++++++
> 2 files changed, 303 insertions(+), 125 deletions(-)
> delete mode 100644 Documentation/devicetree/bindings/usb/dwc3.txt
> create mode 100644 Documentation/devicetree/bindings/usb/snps,dwc3.yaml
>
> diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt b/Documentation/devicetree/bindings/usb/dwc3.txt
> deleted file mode 100644
> index d03edf9d3935..000000000000
> --- a/Documentation/devicetree/bindings/usb/dwc3.txt
> +++ /dev/null
> @@ -1,125 +0,0 @@
> -synopsys DWC3 CORE
> -
> -DWC3- USB3 CONTROLLER. Complies to the generic USB binding properties
> - as described in 'usb/generic.txt'
> -
> -Required properties:
> - - compatible: must be "snps,dwc3"
> - - reg : Address and length of the register set for the device
> - - interrupts: Interrupts used by the dwc3 controller.
> - - clock-names: list of clock names. Ideally should be "ref",
> - "bus_early", "suspend" but may be less or more.
> - - clocks: list of phandle and clock specifier pairs corresponding to
> - entries in the clock-names property.
> -
> -Exception for clocks:
> - clocks are optional if the parent node (i.e. glue-layer) is compatible to
> - one of the following:
> - "cavium,octeon-7130-usb-uctl"
> - "qcom,dwc3"
> - "samsung,exynos5250-dwusb3"
> - "samsung,exynos5433-dwusb3"
> - "samsung,exynos7-dwusb3"
> - "sprd,sc9860-dwc3"
> - "st,stih407-dwc3"
> - "ti,am437x-dwc3"
> - "ti,dwc3"
> - "ti,keystone-dwc3"
> - "rockchip,rk3399-dwc3"
> - "xlnx,zynqmp-dwc3"
> -
> -Optional properties:
> - - usb-phy : array of phandle for the PHY device. The first element
> - in the array is expected to be a handle to the USB2/HS PHY and
> - the second element is expected to be a handle to the USB3/SS PHY
> - - phys: from the *Generic PHY* bindings
> - - phy-names: from the *Generic PHY* bindings; supported names are "usb2-phy"
> - or "usb3-phy".
> - - resets: set of phandle and reset specifier pairs
> - - snps,usb2-lpm-disable: indicate if we don't want to enable USB2 HW LPM
> - - snps,usb3_lpm_capable: determines if platform is USB3 LPM capable
> - - snps,dis-start-transfer-quirk: when set, disable isoc START TRANSFER command
> - failure SW work-around for DWC_usb31 version 1.70a-ea06
> - and prior.
> - - snps,disable_scramble_quirk: true when SW should disable data scrambling.
> - Only really useful for FPGA builds.
> - - snps,has-lpm-erratum: true when DWC3 was configured with LPM Erratum enabled
> - - snps,lpm-nyet-threshold: LPM NYET threshold
> - - snps,u2exit_lfps_quirk: set if we want to enable u2exit lfps quirk
> - - snps,u2ss_inp3_quirk: set if we enable P3 OK for U2/SS Inactive quirk
> - - snps,req_p1p2p3_quirk: when set, the core will always request for
> - P1/P2/P3 transition sequence.
> - - snps,del_p1p2p3_quirk: when set core will delay P1/P2/P3 until a certain
> - amount of 8B10B errors occur.
> - - snps,del_phy_power_chg_quirk: when set core will delay PHY power change
> - from P0 to P1/P2/P3.
> - - snps,lfps_filter_quirk: when set core will filter LFPS reception.
> - - snps,rx_detect_poll_quirk: when set core will disable a 400us delay to start
> - Polling LFPS after RX.Detect.
> - - snps,tx_de_emphasis_quirk: when set core will set Tx de-emphasis value.
> - - snps,tx_de_emphasis: the value driven to the PHY is controlled by the
> - LTSSM during USB3 Compliance mode.
> - - snps,dis_u3_susphy_quirk: when set core will disable USB3 suspend phy.
> - - snps,dis_u2_susphy_quirk: when set core will disable USB2 suspend phy.
> - - snps,dis_enblslpm_quirk: when set clears the enblslpm in GUSB2PHYCFG,
> - disabling the suspend signal to the PHY.
> - - snps,dis-u1-entry-quirk: set if link entering into U1 needs to be disabled.
> - - snps,dis-u2-entry-quirk: set if link entering into U2 needs to be disabled.
> - - snps,dis_rxdet_inp3_quirk: when set core will disable receiver detection
> - in PHY P3 power state.
> - - snps,dis-u2-freeclk-exists-quirk: when set, clear the u2_freeclk_exists
> - in GUSB2PHYCFG, specify that USB2 PHY doesn't provide
> - a free-running PHY clock.
> - - snps,dis-del-phy-power-chg-quirk: when set core will change PHY power
> - from P0 to P1/P2/P3 without delay.
> - - snps,dis-tx-ipgap-linecheck-quirk: when set, disable u2mac linestate check
> - during HS transmit.
> - - snps,parkmode-disable-ss-quirk: when set, all SuperSpeed bus instances in
> - park mode are disabled.
> - - snps,dis_metastability_quirk: when set, disable metastability workaround.
> - CAUTION: use only if you are absolutely sure of it.
> - - snps,is-utmi-l1-suspend: true when DWC3 asserts output signal
> - utmi_l1_suspend_n, false when asserts utmi_sleep_n
> - - snps,hird-threshold: HIRD threshold
> - - snps,hsphy_interface: High-Speed PHY interface selection between "utmi" for
> - UTMI+ and "ulpi" for ULPI when the DWC_USB3_HSPHY_INTERFACE has value 3.
> - - snps,quirk-frame-length-adjustment: Value for GFLADJ_30MHZ field of GFLADJ
> - register for post-silicon frame length adjustment when the
> - fladj_30mhz_sdbnd signal is invalid or incorrect.
> - - snps,rx-thr-num-pkt-prd: periodic ESS RX packet threshold count - host mode
> - only. Set this and rx-max-burst-prd to a valid,
> - non-zero value 1-16 (DWC_usb31 programming guide
> - section 1.2.4) to enable periodic ESS RX threshold.
> - - snps,rx-max-burst-prd: max periodic ESS RX burst size - host mode only. Set
> - this and rx-thr-num-pkt-prd to a valid, non-zero value
> - 1-16 (DWC_usb31 programming guide section 1.2.4) to
> - enable periodic ESS RX threshold.
> - - snps,tx-thr-num-pkt-prd: periodic ESS TX packet threshold count - host mode
> - only. Set this and tx-max-burst-prd to a valid,
> - non-zero value 1-16 (DWC_usb31 programming guide
> - section 1.2.3) to enable periodic ESS TX threshold.
> - - snps,tx-max-burst-prd: max periodic ESS TX burst size - host mode only. Set
> - this and tx-thr-num-pkt-prd to a valid, non-zero value
> - 1-16 (DWC_usb31 programming guide section 1.2.3) to
> - enable periodic ESS TX threshold.
> -
> - - <DEPRECATED> tx-fifo-resize: determines if the FIFO *has* to be reallocated.
> - - snps,incr-burst-type-adjustment: Value for INCR burst type of GSBUSCFG0
> - register, undefined length INCR burst type enable and INCRx type.
> - When just one value, which means INCRX burst mode enabled. When
> - more than one value, which means undefined length INCR burst type
> - enabled. The values can be 1, 4, 8, 16, 32, 64, 128 and 256.
> -
> - - in addition all properties from usb-xhci.txt from the current directory are
> - supported as well
> -
> -
> -This is usually a subnode to DWC3 glue to which it is connected.
> -
> -dwc3@4a030000 {
> - compatible = "snps,dwc3";
> - reg = <0x4a030000 0xcfff>;
> - interrupts = <0 92 4>
> - usb-phy = <&usb2_phy>, <&usb3,phy>;
> - snps,incr-burst-type-adjustment = <1>, <4>, <8>, <16>;
> -};
> diff --git a/Documentation/devicetree/bindings/usb/snps,dwc3.yaml b/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
> new file mode 100644
> index 000000000000..079617891da6
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
> @@ -0,0 +1,303 @@
> +# SPDX-License-Identifier: GPL-2.0
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/usb/snps,dwc3.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Synopsys DesignWare USB3 Controller
> +
> +maintainers:
> + - Felipe Balbi <balbi@kernel.org>
> +
> +description:
> + This is usually a subnode to DWC3 glue to which it is connected, but can also
> + be presented as a standalone DT node with an optional vendor-specific
> + compatible string.
> +
> +allOf:
> + - $ref: usb-drd.yaml#
> + - if:
> + properties:
> + dr_mode:
> + const: peripheral
> + then:
> + $ref: usb.yaml#

This part could be done in usb-drd.yaml?

> + else:
> + $ref: usb-xhci.yaml#

I'd really prefer if all the schema can just be applied unconditionally.
Shouldn't someone (like a bootloader) be able to change dr_mode without
changing anything else to set the mode? That would imply all the
schemas can be applied.

Rob