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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 AD86FC43142 for ; Fri, 22 Jun 2018 08:24:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 64A1623EEA for ; Fri, 22 Jun 2018 08:24:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 64A1623EEA Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bootlin.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754128AbeFVIYr (ORCPT ); Fri, 22 Jun 2018 04:24:47 -0400 Received: from mail.bootlin.com ([62.4.15.54]:45265 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751194AbeFVIYo (ORCPT ); Fri, 22 Jun 2018 04:24:44 -0400 Received: by mail.bootlin.com (Postfix, from userid 110) id A4E7820799; Fri, 22 Jun 2018 10:24:41 +0200 (CEST) Received: from bbrezillon (AAubervilliers-681-1-50-153.w90-88.abo.wanadoo.fr [90.88.168.153]) by mail.bootlin.com (Postfix) with ESMTPSA id F2A58206FF; Fri, 22 Jun 2018 10:24:40 +0200 (CEST) Date: Fri, 22 Jun 2018 10:24:41 +0200 From: Boris Brezillon To: Linus Walleij Cc: Wolfram Sang , linux-i2c@vger.kernel.org, Jonathan Corbet , linux-doc@vger.kernel.org, Greg Kroah-Hartman , Arnd Bergmann , Przemyslaw Sroka , Arkadiusz Golec , Alan Douglas , Bartosz Folta , Damian Kos , Alicja Jurasik-Urbaniak , Cyprian Wronka , Suresh Punnoose , Rafal Ciepiela , Thomas Petazzoni , Nishanth Menon , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , "linux-kernel@vger.kernel.org" , Vitor Soares , Geert Uytterhoeven , Xiang Lin , "open list:GPIO SUBSYSTEM" Subject: Re: [PATCH v4 09/10] gpio: Add a driver for Cadence I3C GPIO expander Message-ID: <20180622102441.35856a50@bbrezillon> In-Reply-To: References: <20180330074751.25987-1-boris.brezillon@bootlin.com> <20180330074751.25987-10-boris.brezillon@bootlin.com> X-Mailer: Claws Mail 3.15.0-dirty (GTK+ 2.24.31; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Linus, I realize I never replied to this review. On Thu, 26 Apr 2018 10:44:26 +0200 Linus Walleij wrote: > On Fri, Mar 30, 2018 at 9:47 AM, Boris Brezillon > wrote: > > > Add a driver for Cadence I3C GPIO expander. > > > > Signed-off-by: Boris Brezillon > > This is pretty much OK, and I don't want to raise the bar > even higher for you to get this code into the kernel, so: > Acked-by: Linus Walleij Thanks. > > The following is an observation for future improvement: > > > +static int cdns_i3c_gpio_read_reg(struct cdns_i3c_gpio *gpioc, u8 reg, > > + u8 *val) > > +{ > > + struct i3c_priv_xfer xfers[] = { > > + { > > + .len = sizeof(reg), > > + .data.out = ®, > > + }, > > + { > > + .rnw = true, > > + .len = sizeof(*val), > > + .data.in = val, > > + }, > > + }; > > + > > + return i3c_device_do_priv_xfers(gpioc->i3cdev, xfers, > > + ARRAY_SIZE(xfers)); > > +} > > + > > +static int cdns_i3c_gpio_write_reg(struct cdns_i3c_gpio *gpioc, u8 reg, > > + u8 val) > > +{ > > + struct i3c_priv_xfer xfers[] = { > > + { > > + .len = sizeof(reg), > > + .data.out = ®, > > + }, > > + { > > + .len = sizeof(val), > > + .data.out = &val, > > + }, > > + }; > > + > > + return i3c_device_do_priv_xfers(gpioc->i3cdev, xfers, > > + ARRAY_SIZE(xfers)); > > +} > > This is starting to resemble > drivers/base/regmap/regmap-i2c.c > > Maybe we should very quickly add regmap-i3c.c as this > infrastructre has had a great positive effect on may kernel > subsystems. Yes I considered that too, I was just waiting for at least one other user before adding this regmap-i3c implementation. > > > +static int cdns_i3c_gpio_get_direction(struct gpio_chip *g, unsigned offset) > > +{ > > + struct cdns_i3c_gpio *gpioc = gpioc_to_cdns_gpioc(g); > > + > > + return gpioc->dir & BIT(offset); > > I would: > > return !!(gpioc->dir & BIT(offset)); > > So you clamp it to bit 0. Will fix that in my v5. Thanks for your review. Boris