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=-10.5 required=3.0 tests=BAYES_00,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 B6641C4338F for ; Mon, 9 Aug 2021 19:40:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 99A2F61056 for ; Mon, 9 Aug 2021 19:40:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234316AbhHITk1 (ORCPT ); Mon, 9 Aug 2021 15:40:27 -0400 Received: from mail.kernel.org ([198.145.29.99]:51468 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234135AbhHITk0 (ORCPT ); Mon, 9 Aug 2021 15:40:26 -0400 Received: from jic23-huawei (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 3399761019; Mon, 9 Aug 2021 19:40:03 +0000 (UTC) Date: Mon, 9 Aug 2021 20:42:53 +0100 From: Jonathan Cameron To: "Liam Beguin" Cc: , , , , , , , Subject: Re: [PATCH v5 3/5] iio: adc: ad7949: add support for internal vref Message-ID: <20210809204253.357f97b2@jic23-huawei> In-Reply-To: References: <20210808015659.2955443-1-liambeguin@gmail.com> <20210808015659.2955443-4-liambeguin@gmail.com> <20210808173630.5c384a4b@jic23-huawei> X-Mailer: Claws Mail 4.0.0 (GTK+ 3.24.30; 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: devicetree@vger.kernel.org ... > + > > > static int ad7949_spi_probe(struct spi_device *spi) > > > { > > > u32 spi_ctrl_mask = spi->controller->bits_per_word_mask; > > > struct device *dev = &spi->dev; > > > const struct ad7949_adc_spec *spec; > > > struct ad7949_adc_chip *ad7949_adc; > > > + struct ad7949_channel *ad7949_chan; > > > + struct fwnode_handle *child; > > > struct iio_dev *indio_dev; > > > + int mode; > > > + u32 tmp; > > > int ret; > > > + int i; > > > > > > indio_dev = devm_iio_device_alloc(dev, sizeof(*ad7949_adc)); > > > if (!indio_dev) { > > > @@ -343,16 +383,82 @@ static int ad7949_spi_probe(struct spi_device *spi) > > > return -EINVAL; > > > } > > > > > > - ad7949_adc->vref = devm_regulator_get(dev, "vref"); > > > + /* Setup external voltage ref, buffered? */ > > > + ad7949_adc->vref = devm_regulator_get_optional(dev, "vrefin"); > > > if (IS_ERR(ad7949_adc->vref)) { > > > - dev_err(dev, "fail to request regulator\n"); > > > - return PTR_ERR(ad7949_adc->vref); > > > + ret = PTR_ERR(ad7949_adc->vref); > > > + if (ret != -ENODEV) > > > + return ret; > > > + /* unbuffered? */ > > > + ad7949_adc->vref = devm_regulator_get_optional(dev, "vref"); > > > + if (IS_ERR(ad7949_adc->vref)) { > > > + ret = PTR_ERR(ad7949_adc->vref); > > > + if (ret != -ENODEV) > > > + return ret; > > > + /* Internal then */ > > > + mode = AD7949_CFG_VAL_REF_INT_4096; > > > + } else { > > > + mode = AD7949_CFG_VAL_REF_EXT_TEMP; > > > + } > > > + } else { > > > + mode = AD7949_CFG_VAL_REF_EXT_TEMP_BUF; > > > } > > > > > > - ret = regulator_enable(ad7949_adc->vref); > > > - if (ret < 0) { > > > - dev_err(dev, "fail to enable regulator\n"); > > > - return ret; > > > + if (mode & AD7949_CFG_VAL_REF_EXTERNAL) { > > > + ret = regulator_enable(ad7949_adc->vref); > > > + if (ret < 0) { > > > + dev_err(dev, "fail to enable regulator\n"); > > > + return ret; > > > + } > > > + > > > + ret = devm_add_action_or_reset(dev, ad7949_disable_reg, > > > + ad7949_adc->vref); > > > + if (ret) > > > + return ret; > > > + } > > > + > > > + ad7949_adc->channels = devm_kcalloc(dev, spec->num_channels, > > > + sizeof(*ad7949_adc->channels), > > > + GFP_KERNEL); > > > + if (!ad7949_adc->channels) { > > > + dev_err(dev, "unable to allocate ADC channels\n"); > > > + return -ENOMEM; > > > + } > > > + > > > + /* Initialize all channel structures */ > > > + for (i = 0; i < spec->num_channels; i++) > > > + ad7949_adc->channels[i].refsel = mode; > > > + > > > + /* Read channel specific information form the devicetree */ > > > + device_for_each_child_node(dev, child) { > > > + ret = fwnode_property_read_u32(child, "reg", &i); > > > + if (ret) { > > > + dev_err(dev, "missing reg property in %pfw\n", child); > > > + fwnode_handle_put(child); > > > + return ret; > > > + } > > > + > > > + ad7949_chan = &ad7949_adc->channels[i]; > > > + > > > + ret = fwnode_property_read_u32(child, "adi,internal-ref-microvolt", &tmp); > > > + if (ret < 0 && ret != -EINVAL) { > > > + dev_err(dev, "invalid internal reference in %pfw\n", child); > > > + fwnode_handle_put(child); > > > + return ret; > > > + } > > Hi Jonathan, > > > > > So if we are using external voltage, then we'd not expect this to exist. > > ret != -EINVAL should deal with that. However, we then hit the following > > switch > > and temp isn't set to an appropriate value so we get the error. > > > > Am I missing something? > > You're right that using an external reference, will cause this to fail. > My apologies, I've done a poor job of testing the last two revisions of > this patch. I'll do better. > > Since a regulator is also required when we're using an external source, > I'll add a check for that. Something like this: > > ret = fwnode_property_read_u32(child, "adi,internal-ref-microvolt", &tmp); > if (ret == -EINVAL && mode & AD7949_CFG_VAL_REF_EXTERNAL) { > continue; > } else if (ret < 0) { > dev_err(dev, "invalid voltage reference in %pfw\n", child); > fwnode_handle_put(child); > return ret; > } Makes sense. > > Given that we can now have a different scale for each channel based on > the vref source, should BIT(IIO_CHAN_INFO_SCALE) be moved to > .info_mask_separate in the channel definition? Yes, good point. Hopefully no one will notice the ABI change *crosses fingers*. Jonathan > > Thanks, > Liam > > > > > > + > > > + switch (tmp) { > > > + case 2500000: > > > + ad7949_chan->refsel = AD7949_CFG_VAL_REF_INT_2500; > > > + break; > > > + case 4096000: > > > + ad7949_chan->refsel = AD7949_CFG_VAL_REF_INT_4096; > > > + break; > > > + default: > > > + dev_err(dev, "unsupported internal voltage reference\n"); > > > + fwnode_handle_put(child); > > > + return -EINVAL; > > > + } > > > } > > > > > > mutex_init(&ad7949_adc->lock); > > > @@ -373,7 +479,6 @@ static int ad7949_spi_probe(struct spi_device *spi) > > > > > > err: > > > mutex_destroy(&ad7949_adc->lock); > > > - regulator_disable(ad7949_adc->vref); > > > > > > return ret; > > > } > > > @@ -385,7 +490,6 @@ static int ad7949_spi_remove(struct spi_device *spi) > > > > > > iio_device_unregister(indio_dev); > > > mutex_destroy(&ad7949_adc->lock); > > > - regulator_disable(ad7949_adc->vref); > > > > > > return 0; > > > } >