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=-6.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=unavailable 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 1A8BCC3F2D1 for ; Wed, 4 Mar 2020 12:03:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E97E721739 for ; Wed, 4 Mar 2020 12:03:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388006AbgCDMDa convert rfc822-to-8bit (ORCPT ); Wed, 4 Mar 2020 07:03:30 -0500 Received: from metis.ext.pengutronix.de ([85.220.165.71]:56243 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387801AbgCDMD3 (ORCPT ); Wed, 4 Mar 2020 07:03:29 -0500 Received: from lupine.hi.pengutronix.de ([2001:67c:670:100:3ad5:47ff:feaf:1a17] helo=lupine) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1j9SkE-00046M-B3; Wed, 04 Mar 2020 13:03:22 +0100 Received: from pza by lupine with local (Exim 4.92) (envelope-from ) id 1j9SkB-0006zp-D7; Wed, 04 Mar 2020 13:03:19 +0100 Message-ID: Subject: Re: [PATCH 25/89] reset: simple: Add reset callback From: Philipp Zabel To: Maxime Ripard , Nicolas Saenz Julienne , Eric Anholt Cc: dri-devel@lists.freedesktop.org, linux-rpi-kernel@lists.infradead.org, bcm-kernel-feedback-list@broadcom.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Dave Stevenson , Tim Gover , Phil Elwell Date: Wed, 04 Mar 2020 13:03:19 +0100 In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT User-Agent: Evolution 3.30.5-1.1 MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:67c:670:100:3ad5:47ff:feaf:1a17 X-SA-Exim-Mail-From: p.zabel@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Maxime, On Mon, 2020-02-24 at 10:06 +0100, Maxime Ripard wrote: > The reset-simple code lacks a reset callback that is still pretty easy to > implement. The only real thing to consider is the delay needed for a device > to be reset, so let's expose that as part of the reset-simple driver data. > > Cc: Philipp Zabel > Signed-off-by: Maxime Ripard This shoulod be done in such a way that simple reset drivers which do not set the reset delay continue to return -ENOTSUPP from reset_control_reset(). > --- > drivers/reset/reset-simple.c | 21 +++++++++++++++++++++ > include/linux/reset/reset-simple.h | 4 ++++ > 2 files changed, 25 insertions(+) > > diff --git a/drivers/reset/reset-simple.c b/drivers/reset/reset-simple.c > index c854aa351640..7a8c56512ae9 100644 > --- a/drivers/reset/reset-simple.c > +++ b/drivers/reset/reset-simple.c > @@ -11,6 +11,7 @@ > * Maxime Ripard > */ > > +#include > #include > #include > #include > @@ -63,6 +64,25 @@ static int reset_simple_deassert(struct reset_controller_dev *rcdev, > return reset_simple_update(rcdev, id, false); > } > > +static int reset_simple_reset(struct reset_controller_dev *rcdev, > + unsigned long id) > +{ > + struct reset_simple_data *data = to_reset_simple_data(rcdev); > + int ret; You could just return -ENOTSUPP here if data->reset_ms == 0. > + ret = reset_simple_assert(rcdev, id); > + if (ret) > + return ret; > + > + mdelay(data->reset_ms); Have you considered specifying the delay in microseconds instead? That would allow to use usleep_range() for shorter delays. > + ret = reset_simple_deassert(rcdev, id); > + if (ret) > + return ret; > + > + return 0; > +} > + > static int reset_simple_status(struct reset_controller_dev *rcdev, > unsigned long id) > { > @@ -80,6 +100,7 @@ static int reset_simple_status(struct reset_controller_dev *rcdev, > const struct reset_control_ops reset_simple_ops = { > .assert = reset_simple_assert, > .deassert = reset_simple_deassert, > + .reset = reset_simple_reset, > .status = reset_simple_status, > }; > EXPORT_SYMBOL_GPL(reset_simple_ops); > diff --git a/include/linux/reset/reset-simple.h b/include/linux/reset/reset-simple.h > index 08ccb25a55e6..a5887f6cbe50 100644 > --- a/include/linux/reset/reset-simple.h > +++ b/include/linux/reset/reset-simple.h > @@ -27,6 +27,9 @@ > * @status_active_low: if true, bits read back as cleared while the reset is > * asserted. Otherwise, bits read back as set while the > * reset is asserted. > + * @reset_ms: Minimum delay in milliseconds needed that needs to be > + * waited for between an assert and a deassert to reset the > + * device. If multiple consumers with different delay requirements are connected to this reset controllers, this must the largest minimum delay. Could you add mention for this in the comment? regards Philipp