From patchwork Mon May 20 17:56:03 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Doug Anderson X-Patchwork-Id: 10952151 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id F0D5816C1 for ; Mon, 20 May 2019 17:56:16 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DEE7628846 for ; Mon, 20 May 2019 17:56:16 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D032C288DC; Mon, 20 May 2019 17:56:16 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5A29F28846 for ; Mon, 20 May 2019 17:56:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726793AbfETR4P (ORCPT ); Mon, 20 May 2019 13:56:15 -0400 Received: from mail-pg1-f194.google.com ([209.85.215.194]:39574 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726818AbfETR4O (ORCPT ); Mon, 20 May 2019 13:56:14 -0400 Received: by mail-pg1-f194.google.com with SMTP id w22so7132432pgi.6 for ; Mon, 20 May 2019 10:56:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=4CUjhStx9Q1czDRNZdSf4vceu5KbZk+h2BQP0hsuERo=; b=MFNW8y7mNTo6N1VqA5T5Mo6RzW9jVYQYoQ6qYJl5we7NYdFnZFDyx0sLkY0ogXYLwn enWsfvygO1Z23KozLJnz0N3qWtFlricRqhBNrAnq4nJz3++GH7QK0Drjjj2wHUSWnds0 fpeGcp4z76OpMh6bXOsowHGITGPi2pbzJqyJo= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=4CUjhStx9Q1czDRNZdSf4vceu5KbZk+h2BQP0hsuERo=; b=ersvZkT+qlmJeoJycelmqLxxQ0g9vLVWgsPGoBdaW+vYPVkq4KWIJ6fY3yIjgPzslU BR55gctvhg0+kBKXXr+VuDkdk66xDPZ6Qob6xswphVBmdTOfQjLs5ZFugoSG+Sp9KZcr +ctwjhkk36Ak1+kW2s2kptXTmer6A+cFhZKFUY+hTm/3zvDBAw4Gc3usqT4czGpTBdB+ waI7vLOxZksFHcejT3kZ0c+1XbYNMSUfuN3WMX38WrZtbJENf/0s2ZuCi41bn/MLqzkZ SAoYFa5Rwf6G/jxpQ2aH7grHvMWiLApb9DhJKutCwwmmOjp3x2XtujJEdS6TqILY0TS2 X40w== X-Gm-Message-State: APjAAAX47PGjPU5o006jl42v5QF+NT6Cu7xZ2g6eA832U/O9YKby5XPy CJ45lDc9kbEr2OsqnYWkIdLRIw== X-Google-Smtp-Source: APXvYqx8PLoZmRIV8cyPnbkbGG132pIi5rrVAVnCDXIAjwYFv8VXCCCG4c1elHrOmzAQBdfYcMChEw== X-Received: by 2002:a62:6341:: with SMTP id x62mr80813484pfb.63.1558374973618; Mon, 20 May 2019 10:56:13 -0700 (PDT) Received: from tictac2.mtv.corp.google.com ([2620:15c:202:1:24fa:e766:52c9:e3b2]) by smtp.gmail.com with ESMTPSA id o2sm16852723pgq.1.2019.05.20.10.56.11 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 20 May 2019 10:56:12 -0700 (PDT) From: Douglas Anderson To: Minas Harutyunyan , Felipe Balbi , heiko@sntech.de Cc: Alan Stern , Artur Petrosyan , amstan@chromium.org, linux-rockchip@lists.infradead.org, William Wu , linux-usb@vger.kernel.org, Stefan Wahren , Randy Li , zyw@rock-chips.com, mka@chromium.org, ryandcase@chromium.org, Amelie Delaunay , jwerner@chromium.org, Elaine Zhang , Douglas Anderson , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Rob Herring , Greg Kroah-Hartman , Mark Rutland Subject: [PATCH v3 1/3] Documentation: dt-bindings: Add snps,need-phy-for-wake for dwc2 USB Date: Mon, 20 May 2019 10:56:03 -0700 Message-Id: <20190520175605.2405-2-dianders@chromium.org> X-Mailer: git-send-email 2.21.0.1020.gf2820cf01a-goog In-Reply-To: <20190520175605.2405-1-dianders@chromium.org> References: <20190520175605.2405-1-dianders@chromium.org> MIME-Version: 1.0 Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Some SoCs with a dwc2 USB controller may need to keep the PHY on to support remote wakeup. Allow specifying this as a device tree property. Signed-off-by: Douglas Anderson Reviewed-by: Rob Herring --- For relevant prior discussion on this patch, see: https://lkml.kernel.org/r/1435017144-2971-3-git-send-email-dianders@chromium.org I didn't make any changes from the prior version since I never found out what Rob thought of my previous arguments. If folks want a change, perhaps they could choose from these options: 1. Assume that all dwc2 hosts would like to keep their PHY on for suspend if there's a USB wakeup enabled, thus we totally drop this binding. This doesn't seem super great to me since I'd bet that many devices that use dwc2 weren't designed for USB wakeup (they may not keep enough clocks or rails on) so we might be wasting power for nothing. 2. Rename this property to "snps,wakeup-from-suspend-with-phy" to make it more obvious that this property is intended both to document that wakeup from suspend is possible and that we need the PHY for said wakeup. 3. Rename this property to "snps,can-wakeup-from-suspend" and assume it's implicit that if we can wakeup from suspend that we need to keep the PHY on. If/when someone shows that a device exists using dwc2 where we can wakeup from suspend without the PHY they can add a new property. NOTE FOR REPOST: - In v2 Rob said [1] he'd prefer something based on the SoC compatibility string, but that doesn't work because not all boards will have the regulator setup / board design / suspend logic necessary to make this work. [1] https://lkml.kernel.org/r/20190430012328.GA25660@bogus Changes in v3: None Changes in v2: None Documentation/devicetree/bindings/usb/dwc2.txt | 3 +++ 1 file changed, 3 insertions(+) diff --git a/Documentation/devicetree/bindings/usb/dwc2.txt b/Documentation/devicetree/bindings/usb/dwc2.txt index 49eac0dc86b0..aafff3a6904d 100644 --- a/Documentation/devicetree/bindings/usb/dwc2.txt +++ b/Documentation/devicetree/bindings/usb/dwc2.txt @@ -42,6 +42,8 @@ Refer to phy/phy-bindings.txt for generic phy consumer properties - g-rx-fifo-size: size of rx fifo size in gadget mode. - g-np-tx-fifo-size: size of non-periodic tx fifo size in gadget mode. - g-tx-fifo-size: size of periodic tx fifo per endpoint (except ep0) in gadget mode. +- snps,need-phy-for-wake: If present indicates that the phy needs to be left + on for remote wakeup during suspend. - snps,reset-phy-on-wake: If present indicates that we need to reset the PHY when we detect a wakeup. This is due to a hardware errata. @@ -58,4 +60,5 @@ Example: clock-names = "otg"; phys = <&usbphy>; phy-names = "usb2-phy"; + snps,need-phy-for-wake; };