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=-15.5 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 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 21113C433FE for ; Sun, 13 Dec 2020 14:24:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D642C22A84 for ; Sun, 13 Dec 2020 14:23:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726854AbgLMOXj (ORCPT ); Sun, 13 Dec 2020 09:23:39 -0500 Received: from mail.kernel.org ([198.145.29.99]:41052 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725778AbgLMOXi (ORCPT ); Sun, 13 Dec 2020 09:23:38 -0500 Received: from archlinux (cpc108967-cmbg20-2-0-cust86.5-4.cable.virginm.net [81.101.6.87]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 069A12253D; Sun, 13 Dec 2020 14:22:56 +0000 (UTC) Date: Sun, 13 Dec 2020 14:22:53 +0000 From: Jonathan Cameron To: Alexandru Ardelean Cc: Alexandru Ardelean , linux-iio , LKML Subject: Re: [PATCH 1/3] iio: dummy: convert all simple allocation devm_ variants Message-ID: <20201213142253.14afd9d9@archlinux> In-Reply-To: References: <20201203095005.72252-1-alexandru.ardelean@analog.com> <20201205163618.3b26334f@archlinux> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 7 Dec 2020 09:22:28 +0200 Alexandru Ardelean wrote: > On Sat, Dec 5, 2020 at 8:46 PM Jonathan Cameron wrote: > > > > On Thu, 3 Dec 2020 11:50:03 +0200 > > Alexandru Ardelean wrote: > > > > > Since a main requirement for an IIO device is to have a parent device > > > object, it makes sense to attach more of the IIO device's objects to the > > > lifetime of the parent object, to clean up the code. > > > The idea is to also provide a base example that is more up-to-date with > > > what's going on lately with most IIO drivers. > > > > To some degree maybe, it's also very very handy for testing odd corner > > cases with. I'd definitely not recommend it as a reference driver > > because it inherently has some odd corners because we need to > > fake various things that don't exist without hardware. > > It's funny because during GSoC it seemed like some people would try to > use this as a starting point, then shift to another working ADC/DAC > example. Hmm. It make sense to use it if you are interested in see what actually turns up in userspace etc as a gsoc student probably doesn't have much hardware that is already supported. But code wise it's somewhat odd and may be less good as an example than a i2c/spi ADC. > I was also thinking about maybe extending this a bit further, to have > it a bit more dynamic at load time [being able to load fake IIO > drivers, load fake data to be read via fake IIO device]. > No idea when this will be ready, but it's on my long todo-list. Sure. It's always been on my long term list to make this driver do more complex stuff, but real parts often get in the way unless I'm proving out something I don't have any real hardware for. > > > > > > > > > This change tackles the simple allocations, to convert them to > > > device-managed calls, and tie them to the parent device. > > > > I'm confused or maybe I missrecall how this works. > > > > IIRC there isn't a parent device... > > > > Maybe we could create one via a bit of smoke and magic. > > Yep, there isn't one. > I'll add one through some smoke, magic, some OF and maybe some fake > i2c/spi device IDs. Hmm. Whatever is done needs to be both non invasive and not imply anything that isn't true. Maybe better off with a platform device than i2c or spi as the parent. Jonathan > > > > > > > > > > > Signed-off-by: Alexandru Ardelean > > > --- > > > drivers/iio/dummy/iio_simple_dummy.c | 29 ++++++++-------------------- > > > 1 file changed, 8 insertions(+), 21 deletions(-) > > > > > > diff --git a/drivers/iio/dummy/iio_simple_dummy.c b/drivers/iio/dummy/iio_simple_dummy.c > > > index c0b7ef900735..2a2e62f780a1 100644 > > > --- a/drivers/iio/dummy/iio_simple_dummy.c > > > +++ b/drivers/iio/dummy/iio_simple_dummy.c > > > @@ -574,11 +574,9 @@ static struct iio_sw_device *iio_dummy_probe(const char *name) > > > * parent = &client->dev; > > > */ > > > > > > - swd = kzalloc(sizeof(*swd), GFP_KERNEL); > > > - if (!swd) { > > > - ret = -ENOMEM; > > > - goto error_kzalloc; > > > - } > > > + swd = devm_kzalloc(parent, sizeof(*swd), GFP_KERNEL); > > > + if (!swd) > > > + return ERR_PTR(-ENOMEM); > > > /* > > > * Allocate an IIO device. > > > * > > > @@ -587,11 +585,9 @@ static struct iio_sw_device *iio_dummy_probe(const char *name) > > > * It also has a region (accessed by iio_priv() > > > * for chip specific state information. > > > */ > > > - indio_dev = iio_device_alloc(parent, sizeof(*st)); > > > - if (!indio_dev) { > > > - ret = -ENOMEM; > > > - goto error_ret; > > > - } > > > + indio_dev = devm_iio_device_alloc(parent, sizeof(*st)); > > > + if (!indio_dev) > > > + return ERR_PTR(-ENOMEM); > > > > > > st = iio_priv(indio_dev); > > > mutex_init(&st->lock); > > > @@ -615,7 +611,7 @@ static struct iio_sw_device *iio_dummy_probe(const char *name) > > > * indio_dev->name = id->name; > > > * indio_dev->name = spi_get_device_id(spi)->name; > > > */ > > > - indio_dev->name = kstrdup(name, GFP_KERNEL); > > > + indio_dev->name = devm_kstrdup(parent, name, GFP_KERNEL); > > > > > > /* Provide description of available channels */ > > > indio_dev->channels = iio_dummy_channels; > > > @@ -632,7 +628,7 @@ static struct iio_sw_device *iio_dummy_probe(const char *name) > > > > > > ret = iio_simple_dummy_events_register(indio_dev); > > > if (ret < 0) > > > - goto error_free_device; > > > + return ERR_PTR(ret); > > > > > > ret = iio_simple_dummy_configure_buffer(indio_dev); > > > if (ret < 0) > > > @@ -649,11 +645,6 @@ static struct iio_sw_device *iio_dummy_probe(const char *name) > > > iio_simple_dummy_unconfigure_buffer(indio_dev); > > > error_unregister_events: > > > iio_simple_dummy_events_unregister(indio_dev); > > > -error_free_device: > > > - iio_device_free(indio_dev); > > > -error_ret: > > > - kfree(swd); > > > -error_kzalloc: > > > return ERR_PTR(ret); > > > } > > > > > > @@ -683,10 +674,6 @@ static int iio_dummy_remove(struct iio_sw_device *swd) > > > > > > iio_simple_dummy_events_unregister(indio_dev); > > > > > > - /* Free all structures */ > > > - kfree(indio_dev->name); > > > - iio_device_free(indio_dev); > > > - > > > return 0; > > > } > > > > >