From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BFB37C433DB for ; Tue, 30 Mar 2021 15:15:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8FC3F6024A for ; Tue, 30 Mar 2021 15:15:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232215AbhC3PPE (ORCPT ); Tue, 30 Mar 2021 11:15:04 -0400 Received: from bhuna.collabora.co.uk ([46.235.227.227]:42608 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232010AbhC3POt (ORCPT ); Tue, 30 Mar 2021 11:14:49 -0400 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: eballetbo) with ESMTPSA id 1AA1F1F45489 Subject: Re: [PATCH v5 1/2] dt-bindings: usb: add analogix,anx7688.yaml To: Dafna Hirschfeld , Laurent Pinchart Cc: linux-usb@vger.kernel.org, devicetree@vger.kernel.org, dri-devel@lists.freedesktop.org, a.hajda@samsung.com, narmstrong@baylibre.com, jonas@kwiboo.se, jernej.skrabec@siol.net, airlied@linux.ie, daniel@ffwll.ch, chunkuang.hu@kernel.org, p.zabel@pengutronix.de, drinkcat@chromium.org, hsinyi@chromium.org, kernel@collabora.com, dafna3@gmail.com, robh+dt@kernel.org, megous@megous.com References: <20210305124351.15079-1-dafna.hirschfeld@collabora.com> <20210305124351.15079-2-dafna.hirschfeld@collabora.com> <35f505ee-d939-4b42-490b-321b961bdec3@collabora.com> <7729b82c-ff87-8d05-366c-4c0a6b85a8f2@collabora.com> From: Enric Balletbo i Serra Message-ID: <1b1352be-fd6d-6cdd-1745-dbca4378fcfa@collabora.com> Date: Tue, 30 Mar 2021 17:14:44 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.0 MIME-Version: 1.0 In-Reply-To: <7729b82c-ff87-8d05-366c-4c0a6b85a8f2@collabora.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Hi Dafna, Many thanks to take this challenge and work on this. On 30/3/21 15:35, Dafna Hirschfeld wrote: > Hi, > > On 05.03.21 16:19, Laurent Pinchart wrote: >> Hi Dafna, >> >> On Fri, Mar 05, 2021 at 04:14:03PM +0100, Dafna Hirschfeld wrote: >>> On 05.03.21 15:34, Laurent Pinchart wrote: >>>> On Fri, Mar 05, 2021 at 01:43:50PM +0100, Dafna Hirschfeld wrote: >>>>> ANX7688 is a USB Type-C port controller with a MUX. It converts HDMI 2.0 to >>>>> DisplayPort 1.3 Ultra-HDi (4096x2160p60). >>>>> The integrated crosspoint switch (the MUX) supports USB 3.1 data transfer >>>>> along with the DisplayPort Alternate Mode signaling over USB Type-C. >>>>> Additionally, an on-chip microcontroller (OCM) is available to manage the >>>>> signal switching, Channel Configuration (CC) detection, USB Power >>>>> Delivery (USB-PD), Vendor Defined Message (VDM) protocol support and other >>>>> functions as defined in the USB TypeC and USB Power Delivery >>>>> specifications. >>>>> >>>>> ANX7688 is found on Acer Chromebook R13 (elm) and on >>>>> Pine64 PinePhone. >>>>> >>>>> Signed-off-by: Dafna Hirschfeld >>>>> --- >>>>>    .../bindings/usb/analogix,anx7688.yaml        | 177 ++++++++++++++++++ >>>>>    1 file changed, 177 insertions(+) >>>>>    create mode 100644 >>>>> Documentation/devicetree/bindings/usb/analogix,anx7688.yaml >>>>> >>>>> diff --git a/Documentation/devicetree/bindings/usb/analogix,anx7688.yaml >>>>> b/Documentation/devicetree/bindings/usb/analogix,anx7688.yaml >>>>> new file mode 100644 >>>>> index 000000000000..6c4dd6b4b28b >>>>> --- /dev/null >>>>> +++ b/Documentation/devicetree/bindings/usb/analogix,anx7688.yaml >>>>> @@ -0,0 +1,177 @@ >>>>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) >>>>> +%YAML 1.2 >>>>> +--- >>>>> +$id: http://devicetree.org/schemas/usb/analogix,anx7688.yaml# >>>>> +$schema: http://devicetree.org/meta-schemas/core.yaml# >>>>> + >>>>> +title: Analogix ANX7688 Type-C Port Controller with HDMI to DP conversion >>>>> + >>>>> +maintainers: >>>>> +  - Nicolas Boichat >>>>> +  - Enric Balletbo i Serra >>>>> + >>>>> +description: | >>>>> +  ANX7688 is a USB Type-C port controller with a MUX. It converts HDMI 2.0 to >>>>> +  DisplayPort 1.3 Ultra-HDi (4096x2160p60). >>>>> +  The integrated crosspoint switch (the MUX) supports USB 3.1 data >>>>> transfer along with >>>>> +  the DisplayPort Alternate Mode signaling over USB Type-C. Additionally, >>>>> +  an on-chip microcontroller (OCM) is available to manage the signal >>>>> switching, >>>>> +  Channel Configuration (CC) detection, USB Power Delivery (USB-PD), Vendor >>>>> +  Defined Message (VDM) protocol support and other functions as defined in >>>>> the >>>>> +  USB TypeC and USB Power Delivery specifications. >>>>> + >>>>> + >>>> >>>> Extra blank line ? >>>> >>>>> +properties: >>>>> +  compatible: >>>>> +    const: analogix,anx7688 >>>>> + >>>>> +  reg: >>>>> +    maxItems: 1 >>>>> + >>>>> +  avdd33-supply: >>>>> +    description: 3.3V Analog core supply voltage. >>>>> + >>>>> +  dvdd18-supply: >>>>> +    description: 1.8V Digital I/O supply voltage. >>>>> + >>>>> +  avdd18-supply: >>>>> +    description: 1.8V Analog core power supply voltage. >>>>> + >>>>> +  avdd10-supply: >>>>> +    description: 1.0V Analog core power supply voltage. >>>>> + >>>>> +  dvdd10-supply: >>>>> +    description: 1.0V Digital core supply voltage. >>>>> + >>>> >>>> That's lots of supplies. If there's a reasonable chance that some of >>>> them will always be driven by the same regulator (especially if the >>>> ANX7688 documentation requires that), then they could be grouped. For >>>> instance dvdd18-supply and avdd18-supply could be grouped into >>>> vdd18-supply. It would still allow us to extend the bindings in a >>>> backward compatible way later if a system uses different regulators. You >>>> have more information about the hardware than I do, so it's your call. > > Can you explain what do you mean by 'grouped' ? > Do you mean that instead of having two properties dvdd18-supply and avdd18-supply > I have only one property vdd18-supply? > You can simplify all this with vdd33, vdd18 vdd10. For the Chromebook case all the analogic and digital part are the same regulator just filtered. That's a common configuration and if there is some hardware that needs it we can extend later. >>>> >>>>> +  hdmi5v-supply: >>>>> +    description: 5V power supply for the HDMI. >>>>> + >>>>> +  hdmi_vt-supply: >>>>> +    description: Termination voltage for HDMI input. >>>> >>>> Maybe hdmi-vt-supply ? >>>> >>>>> + >>>>> +  clocks: >>>>> +    description: The input clock specifier. >>>>> +    maxItems: 1 >>>> >>>> How about >>>> >>>>       items: >>>>         - description: The input clock specifier. >>>> >>>>> + >>>>> +  clock-names: >>>>> +    items: >>>>> +      - const: xtal >>>>> + >>>>> +  hpd-gpios: >>>>> +    description: | >>>>> +      In USB Type-C applications, DP_HPD has no use. In standard DisplayPort >>>>> +      applications, DP_HPD is used as DP hot-plug. >>>>> +    maxItems: 1 >>>>> + >>>>> +  enable-gpios: >>>>> +    description: Chip power down control. No internal pull-down or pull-up >>>>> resistor. >>>>> +    maxItems: 1 >>>>> + >>>>> +  reset-gpios: >>>>> +    description: Reset input signal. Active low. >>>>> +    maxItems: 1 >>>>> + >>>>> +  vbus-det-gpios: >>>>> +    description: | >>>>> +      An input gpio for VBUS detection and high voltage detection, >>>>> +      external resistance divide VBUS voltage to 1/8. >>>>> +    maxItems: 1 >>>>> + >>>>> +  interrupts: >>>>> +    description: | >>>>> +      The interrupt notifies 4 possible events - TCPC ALERT int, PD int, >>>>> DP int, HDMI int. >>>>> +    maxItems: 1 >>>>> + >>>>> +  cabledet-gpios: >>>>> +    description: An output gpio, indicates by the device that a cable is >>>>> plugged. >>>>> +    maxItems: 1 >>>>> + >>>>> +  vbus-ctrl-gpios: >>>>> +    description: >>>>> +      External VBUS power path. Enable VBUS source and disable VBUS sink >>>>> or vice versa. >>>>> +    maxItems: 1 >>>>> + >>>>> +  vconn-en1-gpios: >>>>> +    description: Controls the VCONN switch on the CC1 pin. >>>>> +    maxItems: 1 >>>>> + >>>>> +  vconn-en2-gpios: >>>>> +    description: Controls the VCONN switch on the CC2 pin. >>>>> +    maxItems: 1 >>>>> + >>>>> +  ports: >>>>> +    $ref: /schemas/graph.yaml#/properties/ports >>>>> + >>>>> +    properties: >>>>> +      port@0: >>>>> +        $ref: /schemas/graph.yaml#/properties/port >>>>> +        description: Video port for HDMI input. >>>>> + >>>>> +      port@1: >>>>> +        $ref: /schemas/graph.yaml#/properties/port >>>>> +        description: USB port for the USB3 input. >>>>> + >>>>> +      port@2: >>>>> +        $ref: /schemas/graph.yaml#/properties/port >>>>> +        description: USB Type-c connector, see connector/usb-connector.yaml. >>>>> + >>>>> +    required: >>>>> +      - port@0 >>>> >>>> As all the ports exist at the hardware level, should they always be >>>> present ? The endpoints are optional of course, in case a port isn't >>>> connected on a particular system. >>>> >>>>> + >>>>> +required: >>>>> +  - compatible >>>>> +  - reg >>>> >>>> Shouldn't clocks and regulators be also required ? >>> >>> hmm, theoretically yes. Practically, in the case of Acer R13 (mediatek elm) >>> device, >>> the ANX7688 is powered up and controlled by the Embedded Controller. The >>> kernel only >>> needs to read few registers from that device for the drm bridge driver. >>> (also mentioned that in the cover letter). I think that for the Chromebook you can assume that these supplies are a fixed-regulator that are always on. >> >> This may not be a popular opinion, but if the ANX7688 is fully >> controlled by the EC, I wonder if we shouldn't have an "EC DRM bridge" >> driver that would interrogate the EC instead :-) > We can do this, and tbh will be more easy for us, but we were already asked to do it generic, so ... > But the driver in patch 2/2 do access the anx7688 device with I2C. > It does interrogate the EC. > >> >> Is there a risk of bus conflicts if the EC and the main SoC try to >> access the ANX7688 over I2C at the same time ? > No, there is a kind of i2c tunnel but you don't talk directly with the ANX7688. The EC exposes the anx bus control to the AP. > The SoC access the anx7688 though something called 'i2c-tunnel' (see > google,cros-ec-i2c-tunnel.yaml) > So the I2C tunnels though the EC (I don't know how this is really implemented to > be honest). > > > Thanks, > Dafna > >> >>>> Reviewed-by: Laurent Pinchart >>>> >>>>> + >>>>> +additionalProperties: false >>>>> + >>>>> +examples: >>>>> +  - | >>>>> +    #include >>>>> +    #include >>>>> + >>>>> +    i2c0 { >>>>> +        #address-cells = <1>; >>>>> +        #size-cells = <0>; >>>>> + >>>>> +        anx7688: anx7688@2c { >>>>> +            compatible = "analogix,anx7688"; >>>>> +            reg = <0x2c>; >>>>> +            avdd33-supply = <®_dcdc1>; >>>>> +            dvdd18-supply = <®_ldo_io1>; >>>>> +            avdd18-supply = <®_ldo_io1>; >>>>> +            avdd10-supply = <®_anx1v0>; >>>>> +            dvdd10-supply = <®_anx1v0>; >>>>> +            hdmi_vt-supply = <®_dldo1>; >>>>> +            enable-gpios = <&pio 3 10 GPIO_ACTIVE_LOW>; /* PD10 */ >>>>> +            reset-gpios = <&pio 3 6 GPIO_ACTIVE_HIGH>; /* PD6 */ >>>>> +            interrupt-parent = <&r_pio>; >>>>> +            interrupts = <0 11 IRQ_TYPE_EDGE_FALLING>; /* PL11 */ >>>>> +            cabledet-gpios = <&r_pio 0 8 GPIO_ACTIVE_HIGH>; /* PL8 */ >>>>> +            vconn-en1-gpios = <&pio 3 9 GPIO_ACTIVE_LOW>; /* PD9 */ >>>>> +            vconn-en2-gpios = <&pio 3 9 GPIO_ACTIVE_LOW>; /* PD9 */ >>>>> +            ports { >>>>> +                #address-cells = <1>; >>>>> +                #size-cells = <0>; >>>>> + >>>>> +                port@0 { >>>>> +                    reg = <0>; >>>>> +                    anx7688_in0: endpoint { >>>>> +                        remote-endpoint = <&hdmi0_out>; >>>>> +                    }; >>>>> +                }; >>>>> + >>>>> +                port@1 { >>>>> +                    reg = <1>; >>>>> +                    anx7688_in1: endpoint { >>>>> +                        remote-endpoint = <&usbdrd_phy_ss>; >>>>> +                    }; >>>>> +                }; >>>>> +                port@2 { >>>>> +                    reg = <2>; >>>>> +                    anx7688_out: endpoint { >>>>> +                        remote-endpoint = <&typec_connector>; >>>>> +                    }; >>>>> +                }; >>>>> +            }; >>>>> +        }; >>>>> +    }; >>