Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934179AbcJZQmf (ORCPT ); Wed, 26 Oct 2016 12:42:35 -0400 Received: from mail-wm0-f50.google.com ([74.125.82.50]:37797 "EHLO mail-wm0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933831AbcJZQme (ORCPT ); Wed, 26 Oct 2016 12:42:34 -0400 MIME-Version: 1.0 In-Reply-To: <20161026145756.21689-5-antoine.tenart@free-electrons.com> References: <20161026145756.21689-1-antoine.tenart@free-electrons.com> <20161026145756.21689-5-antoine.tenart@free-electrons.com> From: Mathieu Poirier Date: Wed, 26 Oct 2016 10:42:28 -0600 Message-ID: Subject: Re: [RFC PATCH 4/5] w1: add a callback to call slave when a new device is connected To: Antoine Tenart Cc: Maxime Ripard , pantelis.antoniou@konsulko.com, Mark Rutland , sboyd@codeaurora.org, Thomas Petazzoni , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "devicetree@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2020 Lines: 58 On 26 October 2016 at 08:57, Antoine Tenart wrote: > This patch adds the possibility for slave drivers to register a > callback, to be called whenever a new device matching the slave ID > is connected. > > Signed-off-by: Antoine Tenart > --- > drivers/w1/w1.c | 10 ++++++++++ > drivers/w1/w1_family.h | 2 ++ > 2 files changed, 12 insertions(+) > > diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c > index 80d0cc4e6e7f..7010ffd1ea93 100644 > --- a/drivers/w1/w1.c > +++ b/drivers/w1/w1.c > @@ -659,6 +659,16 @@ static int w1_family_notify(unsigned long action, struct w1_slave *sl) > return err; > } > } > + if (fops->callback) { > + err = fops->callback(sl); > + /* > + * Do not return an error as the slave driver correctly > + * probed. > + */ I don't get this part. What's the point of calling a callback if a failure is not important - maybe I'm just missing something. > + if (err) > + dev_err(&sl->dev, > + "callback call failed. err=%d\n", err); > + } > > break; > case BUS_NOTIFY_DEL_DEVICE: > diff --git a/drivers/w1/w1_family.h b/drivers/w1/w1_family.h > index 10a7a0767187..5e165babc6f3 100644 > --- a/drivers/w1/w1_family.h > +++ b/drivers/w1/w1_family.h > @@ -55,11 +55,13 @@ struct w1_slave; > * @add_slave: add_slave > * @remove_slave: remove_slave > * @groups: sysfs group > + * @callback: called when a new device is discovered > */ > struct w1_family_ops > { > int (* add_slave)(struct w1_slave *); > void (* remove_slave)(struct w1_slave *); > + int (* callback)(struct w1_slave *); > const struct attribute_group **groups; > }; > > -- > 2.10.1 >