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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 26E76C04A68 for ; Thu, 28 Jul 2022 06:41:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233727AbiG1Glg (ORCPT ); Thu, 28 Jul 2022 02:41:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46456 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232855AbiG1GlI (ORCPT ); Thu, 28 Jul 2022 02:41:08 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1B38B50728; Wed, 27 Jul 2022 23:41:06 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 924AF61AC1; Thu, 28 Jul 2022 06:41:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 761DCC433C1; Thu, 28 Jul 2022 06:41:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1658990465; bh=W0XxXdLLkEgMd9X3IxL9GRsb5r2xRaRkUt/W5UWZraI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=bMbtyxn/epbzK5OyRgqr6XtEubLOX+vvDaYhynhx2CPPZ8y4hLP5NsdWTfU+wI07y Ote1DNBBLHv8KwGdKMAAxUJ9ySxZVf39Pfm4FocJuZssv73Jitrrzix/ivg3/fVcEO 9sdIgAv0+COLwSxWCJcevTomkiZYVqGOJ5QUpSSE= Date: Thu, 28 Jul 2022 08:41:01 +0200 From: Greg Kroah-Hartman To: Alexander Stein Cc: Matthias Kaehlcke , Rob Herring , Krzysztof Kozlowski , linux-usb@vger.kernel.org, devicetree@vger.kernel.org Subject: Re: [PATCH v4 1/2] usb: misc: onboard_usb_hub: Add reset-gpio support Message-ID: References: <20220727141117.909361-1-alexander.stein@ew.tq-group.com> <2191669.iZASKD2KPV@steina-w> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2191669.iZASKD2KPV@steina-w> Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Thu, Jul 28, 2022 at 08:20:13AM +0200, Alexander Stein wrote: > Hello Matthias, > > Am Mittwoch, 27. Juli 2022, 19:14:57 CEST schrieb Matthias Kaehlcke: > > Hi Alexander, > > > > (copying my comments from v3 to keep the discussion on the latest version) > > > > On Wed, Jul 27, 2022 at 04:11:16PM +0200, Alexander Stein wrote: > > > Despite default reset upon probe, release reset line after powering up > > > the hub and assert reset again before powering down. > > > > > > Signed-off-by: Alexander Stein > > > --- > > > * Patch 1 dropped as it already applied > > > > > > Changes in v4: > > > * Rebased to [1] commit e0c6b1f3d757 ("USB: usbsevseg: convert sysfs > > > snprintf to sysfs_emit") * Added platform data for usb424 > > > > > > Reset pulse length taken from [2], Table 3-2 Symbol RESET_N > > > Completely untested > > > > > > [1] https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git Branch > > > usb-testing [2] > > > http://ww1.microchip.com/downloads/en/devicedoc/00001692c.pdf > > > > > > drivers/usb/misc/onboard_usb_hub.c | 28 ++++++++++++++++++++++++++++ > > > drivers/usb/misc/onboard_usb_hub.h | 22 +++++++++++++++++----- > > > 2 files changed, 45 insertions(+), 5 deletions(-) > > > > > > diff --git a/drivers/usb/misc/onboard_usb_hub.c > > > b/drivers/usb/misc/onboard_usb_hub.c index de3627af3c84..0c81417dd9a7 > > > 100644 > > > --- a/drivers/usb/misc/onboard_usb_hub.c > > > +++ b/drivers/usb/misc/onboard_usb_hub.c > > > @@ -7,6 +7,7 @@ > > > > > > #include > > > #include > > > > > > +#include > > > > > > #include > > > #include > > > #include > > > > > > @@ -38,6 +39,8 @@ struct usbdev_node { > > > > > > struct onboard_hub { > > > > > > struct regulator *vdd; > > > struct device *dev; > > > > > > + const struct onboard_hub_pdata *pdata; > > > + struct gpio_desc *reset_gpio; > > > > > > bool always_powered_in_suspend; > > > bool is_powered_on; > > > bool going_away; > > > > > > @@ -56,6 +59,9 @@ static int onboard_hub_power_on(struct onboard_hub *hub) > > > > > > return err; > > > > > > } > > > > > > + fsleep(hub->pdata->reset_us); > > > + gpiod_set_value_cansleep(hub->reset_gpio, 0); > > > + > > > > > > hub->is_powered_on = true; > > > > > > return 0; > > > > > > @@ -65,6 +71,11 @@ static int onboard_hub_power_off(struct onboard_hub > > > *hub)> > > > { > > > > > > int err; > > > > > > + if (hub->reset_gpio) { > > > + gpiod_set_value_cansleep(hub->reset_gpio, 1); > > > + fsleep(hub->pdata->reset_us); > > > > Is this delay here actually needed? There is a delay in > > onboard_hub_power_on(), before de-asserting the reset, isn't that enough? > > If you see both delays together you are right, but I tend to think in that way > it is to ensure whenever we apply a reset it is long enough. > As said before the powering on delay is to ensure the pulse length delay even > if there is no reset GPIO but it is controlled by hardware. > > > > + } > > > + > > > > > > err = regulator_disable(hub->vdd); > > > if (err) { > > > > > > dev_err(hub->dev, "failed to disable regulator: %d\n", > err); > > > > > > @@ -219,6 +230,7 @@ static void onboard_hub_attach_usb_driver(struct > > > work_struct *work)> > > > static int onboard_hub_probe(struct platform_device *pdev) > > > { > > > > > > + const struct of_device_id *of_id; > > > > > > struct device *dev = &pdev->dev; > > > struct onboard_hub *hub; > > > int err; > > > > > > @@ -227,10 +239,26 @@ static int onboard_hub_probe(struct platform_device > > > *pdev)> > > > if (!hub) > > > > > > return -ENOMEM; > > > > > > + of_id = of_match_device(onboard_hub_match, &pdev->dev); > > > + if (!of_id) > > > + return -ENODEV; > > > + > > > + hub->pdata = of_id->data; > > > + if (!hub->pdata) > > > + return -EINVAL; > > > + > > > > > > hub->vdd = devm_regulator_get(dev, "vdd"); > > > if (IS_ERR(hub->vdd)) > > > > > > return PTR_ERR(hub->vdd); > > > > > > + hub->reset_gpio = devm_gpiod_get_optional(dev, "reset", > > > + > GPIOD_OUT_HIGH); > > > + if (IS_ERR(hub->reset_gpio)) > > > + return dev_err_probe(dev, PTR_ERR(hub->reset_gpio), > "failed to get > > > reset GPIO\n"); + > > > + if (hub->reset_gpio) > > > + fsleep(hub->pdata->reset_us); > > > > Same question here: onboard_hub_power_on() is called a few lines below and > > has a delay before de-asserting the reset. Is the delay here really needed? > > This actually looks like the delay is duplicated here. I agree with removing > this. > How shall we proceed now that the whole series (incl. the bindings patch 1/3 > from v3) has landed in usb-testing? I can create a patch on top of this if > this is the way to go. Please do.