From patchwork Wed Sep 8 15:25:24 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Boor X-Patchwork-Id: 12481359 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 5B765C433F5 for ; Wed, 8 Sep 2021 15:25:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 359BC6108D for ; Wed, 8 Sep 2021 15:25:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348081AbhIHP0y (ORCPT ); Wed, 8 Sep 2021 11:26:54 -0400 Received: from mail.kernelconcepts.de ([188.40.83.200]:40656 "EHLO mail.kernelconcepts.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344656AbhIHP0y (ORCPT ); Wed, 8 Sep 2021 11:26:54 -0400 Received: from [217.146.132.69] (helo=yoda.kc.loc) by mail.kernelconcepts.de with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.89) (envelope-from ) id 1mNzSH-0000tc-TD; Wed, 08 Sep 2021 17:25:42 +0200 From: Florian Boor To: jic23@kernel.org Cc: linux-iio@vger.kernel.org, Jonathan.Cameron@huawei.com, Michael.Hennerich@analog.com, Florian Boor Subject: [PATCH v2 1/2] iio: adc: ad799x: Implement selecting external reference voltage input on AD7991, AD7995 and AD7999. Date: Wed, 8 Sep 2021 17:25:24 +0200 Message-Id: <20210908152525.2946785-1-florian.boor@kernelconcepts.de> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org Make use of the AD7991_REF_SEL bit and support using the external reference voltage if 'vref-supply' is present. Signed-off-by: Florian Boor --- Changes in v2: - Check if a provided external vref regulator is provided. - Drop unused setting - Add ad79xx documentation (second patch) drivers/iio/adc/ad799x.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) diff --git a/drivers/iio/adc/ad799x.c b/drivers/iio/adc/ad799x.c index 18bf8386d50a..2ff926a4e9b3 100644 --- a/drivers/iio/adc/ad799x.c +++ b/drivers/iio/adc/ad799x.c @@ -770,6 +770,8 @@ static int ad799x_probe(struct i2c_client *client, const struct i2c_device_id *id) { int ret; + int extra_config = 0; + bool vref_external = true; struct ad799x_state *st; struct iio_dev *indio_dev; const struct ad799x_chip_info *chip_info = @@ -797,7 +799,15 @@ static int ad799x_probe(struct i2c_client *client, ret = regulator_enable(st->reg); if (ret) return ret; - st->vref = devm_regulator_get(&client->dev, "vref"); + + /* check if an external reference is supplied */ + st->vref = devm_regulator_get_optional(&client->dev, "vref"); + + if (PTR_ERR(st->vref) == -ENODEV) { + vref_external = false; + /* get dummy */ + st->vref = devm_regulator_get(&client->dev, "vref"); + } if (IS_ERR(st->vref)) { ret = PTR_ERR(st->vref); goto error_disable_reg; @@ -806,6 +816,13 @@ static int ad799x_probe(struct i2c_client *client, if (ret) goto error_disable_reg; + /* use external reference voltage, optional if regulator present */ + if (vref_external && + ((st->id == ad7991) || (st->id == ad7995) || (st->id == ad7999))) { + dev_info(&client->dev, "Using external reference voltage\n"); + extra_config |= AD7991_REF_SEL; + } + st->client = client; indio_dev->name = id->name; @@ -815,7 +832,7 @@ static int ad799x_probe(struct i2c_client *client, indio_dev->channels = st->chip_config->channel; indio_dev->num_channels = chip_info->num_channels; - ret = ad799x_update_config(st, st->chip_config->default_config); + ret = ad799x_update_config(st, st->chip_config->default_config | extra_config); if (ret) goto error_disable_vref;