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=-14.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 CA8EDC43463 for ; Sat, 19 Sep 2020 15:14:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 925862100A for ; Sat, 19 Sep 2020 15:14:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600528485; bh=zP8Pa38cTNoem5fU+XzQBXZ+YfedHS0wIZJdarVDrUU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=KrqQcb1j4dqUIaaRurQG9+J2ueBtTYMYP1VzAMfpo0ouBmtRyGvSF8eW5x4gAenQN 85XZ72KTKwQ1FL5yi1bI36B+gr4dgUZHuRbNWzcNN+uBmHZ1uw/VdvW9zC2abr30uw mmzyB6EeqedWzK38cPSl1Kl1dfqkG6QZMyEKfo8Y= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726546AbgISPOo (ORCPT ); Sat, 19 Sep 2020 11:14:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:56766 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726438AbgISPOo (ORCPT ); Sat, 19 Sep 2020 11:14:44 -0400 Received: from archlinux (cpc149474-cmbg20-2-0-cust94.5-4.cable.virginm.net [82.4.196.95]) (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 527842098B; Sat, 19 Sep 2020 15:14:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600528483; bh=zP8Pa38cTNoem5fU+XzQBXZ+YfedHS0wIZJdarVDrUU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=xUhA/rgcIjgaNupVjczPNhAIbsTj7s8d53STO50rzbjkA9a29CYOPxdFoX4D34lZv 6UVeEkPZS67mddp6xyj7deYa8M20f49FvepHxAccl8Oukr5Ycok8JJ5gXr3hinI8nu 6i3Tyo7oF53JC6oNr6y5zBrDhtrmmR7TlnLTQnQA= Date: Sat, 19 Sep 2020 16:14:40 +0100 From: Jonathan Cameron To: Cristian Pop Cc: , Subject: Re: [PATCH v5] iio: adc: ad7768-1: Add channel label example Message-ID: <20200919161440.2cb17583@archlinux> In-Reply-To: <20200918093356.93670-1-cristian.pop@analog.com> References: <20200918093356.93670-1-cristian.pop@analog.com> X-Mailer: Claws Mail 3.17.6 (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 Fri, 18 Sep 2020 12:33:56 +0300 Cristian Pop wrote: > This is a demo usage of new "label" attribute for channel. While I can see this is a demo in someways, I assume we also have a valid usecase for doing this beyond as a demo! So perhaps rephrase that intro. > > Signed-off-by: Cristian Pop > --- > Changes in V5: > Create a separate patch file for this commit > drivers/iio/adc/ad7768-1.c | 49 ++++++++++++++++++++++++++++++++++++++ > 1 file changed, 49 insertions(+) > > diff --git a/drivers/iio/adc/ad7768-1.c b/drivers/iio/adc/ad7768-1.c > index 0d132708c429..5ca9f9febb5a 100644 > --- a/drivers/iio/adc/ad7768-1.c > +++ b/drivers/iio/adc/ad7768-1.c > @@ -161,6 +161,7 @@ struct ad7768_state { > struct completion completion; > struct iio_trigger *trig; > struct gpio_desc *gpio_sync_in; > + const char **labels; > /* > * DMA (thus cache coherency maintenance) requires the > * transfer buffers to live in their own cache lines. > @@ -407,6 +408,14 @@ static int ad7768_write_raw(struct iio_dev *indio_dev, > } > } > > +static int ad7768_read_label(struct iio_dev *indio_dev, > + const struct iio_chan_spec *chan, char *label) > +{ > + struct ad7768_state *st = iio_priv(indio_dev); > + > + return sprintf(label, "%s\n", st->labels[chan->channel]); > +} > + > static struct attribute *ad7768_attributes[] = { > &iio_dev_attr_sampling_frequency_available.dev_attr.attr, > NULL > @@ -420,6 +429,7 @@ static const struct iio_info ad7768_info = { > .attrs = &ad7768_group, > .read_raw = &ad7768_read_raw, > .write_raw = &ad7768_write_raw, > + .read_label = ad7768_read_label, > .debugfs_reg_access = &ad7768_reg_access, > }; > > @@ -538,6 +548,41 @@ static void ad7768_clk_disable(void *data) > clk_disable_unprepare(st->mclk); > } > > +static int ad7768_set_channel_label(struct iio_dev *indio_dev, > + int num_channels) > +{ > + struct ad7768_state *st = iio_priv(indio_dev); > + struct device *device = indio_dev->dev.parent; > + struct fwnode_handle *fwnode; > + struct fwnode_handle *child; > + const char *label; > + int crt_ch = 0; > + > + st->labels = devm_kcalloc(indio_dev->dev.parent, > + num_channels, > + sizeof(**st->labels), I think that ends up being the size of a single character which isn't the intent. I assume aim is a suitable sized array of pointers to strings which we will fill in later? If so we can probably just use a static sized array as the maximum number of channels is well constrained. In this particular driver that is 1 I think! > + GFP_KERNEL); > + > + if (!st->labels) > + return -ENOMEM; > + > + fwnode = dev_fwnode(device); > + fwnode_for_each_child_node(fwnode, child) { > + if (fwnode_property_read_u32(child, "reg", &crt_ch)) > + continue; > + > + if (crt_ch >= num_channels) > + continue; > + > + if (fwnode_property_read_string(child, "label", &label)) > + continue; > + > + st->labels[crt_ch] = label; > + } > + > + return 0; > +} > + > static int ad7768_probe(struct spi_device *spi) > { > struct ad7768_state *st; > @@ -611,6 +656,10 @@ static int ad7768_probe(struct spi_device *spi) > > init_completion(&st->completion); > > + ret = ad7768_set_channel_label(indio_dev, ARRAY_SIZE(ad7768_channels)); > + if (ret) > + return ret; > + > ret = devm_request_irq(&spi->dev, spi->irq, > &ad7768_interrupt, > IRQF_TRIGGER_RISING | IRQF_ONESHOT,