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=-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 69596C433EF for ; Tue, 14 Sep 2021 14:52:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 456A360FD7 for ; Tue, 14 Sep 2021 14:52:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233055AbhINOxR (ORCPT ); Tue, 14 Sep 2021 10:53:17 -0400 Received: from mail.kernelconcepts.de ([188.40.83.200]:45538 "EHLO mail.kernelconcepts.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231816AbhINOxR (ORCPT ); Tue, 14 Sep 2021 10:53:17 -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 1mQ9mp-0003tp-BJ; Tue, 14 Sep 2021 16:51:51 +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 1/2] iio: adc: ad799x: Implement selecting external reference voltage input on AD7991, AD7995 and AD7999. Date: Tue, 14 Sep 2021 16:51:41 +0200 Message-Id: <20210914145142.138324-1-florian.boor@kernelconcepts.de> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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. Use VCC voltage supply as reference if no extra reference is supplied. Signed-off-by: Florian Boor --- Changes in v3: - Do not create dummy reference regulator, check for vref presence where needed. - Use VCC as reference if no extra reference voltage is provided - Add interrupt information to documentation 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 | 60 ++++++++++++++++++++++++++++------------ 1 file changed, 43 insertions(+), 17 deletions(-) diff --git a/drivers/iio/adc/ad799x.c b/drivers/iio/adc/ad799x.c index 18bf8386d50a..af72fd980030 100644 --- a/drivers/iio/adc/ad799x.c +++ b/drivers/iio/adc/ad799x.c @@ -299,7 +299,11 @@ static int ad799x_read_raw(struct iio_dev *indio_dev, GENMASK(chan->scan_type.realbits - 1, 0); return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: - ret = regulator_get_voltage(st->vref); + if (st->vref) + ret = regulator_get_voltage(st->vref); + else + ret = regulator_get_voltage(st->reg); + if (ret < 0) return ret; *val = ret / 1000; @@ -770,6 +774,7 @@ static int ad799x_probe(struct i2c_client *client, const struct i2c_device_id *id) { int ret; + int extra_config = 0; struct ad799x_state *st; struct iio_dev *indio_dev; const struct ad799x_chip_info *chip_info = @@ -797,14 +802,28 @@ 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 (IS_ERR(st->vref)) { - ret = PTR_ERR(st->vref); - goto error_disable_reg; + st->vref = NULL; + dev_info(&client->dev, "Using VCC reference voltage\n"); + } else { + /* Use external reference voltage if supported by hardware. + * This is optional if voltage / regulator present, use VCC otherwise. + */ + if ((st->id == ad7991) || (st->id == ad7995) || (st->id == ad7999)) { + dev_info(&client->dev, "Using external reference voltage\n"); + extra_config |= AD7991_REF_SEL; + ret = regulator_enable(st->vref); + if (ret) + goto error_disable_reg; + } else { + st->vref = NULL; + dev_warn(&client->dev, "Supplied reference not supported\n"); + } } - ret = regulator_enable(st->vref); - if (ret) - goto error_disable_reg; st->client = client; @@ -815,7 +834,7 @@ 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; @@ -845,7 +864,8 @@ static int ad799x_probe(struct i2c_client *client, error_cleanup_ring: iio_triggered_buffer_cleanup(indio_dev); error_disable_vref: - regulator_disable(st->vref); + if (st->vref) + regulator_disable(st->vref); error_disable_reg: regulator_disable(st->reg); @@ -860,7 +880,8 @@ static int ad799x_remove(struct i2c_client *client) iio_device_unregister(indio_dev); iio_triggered_buffer_cleanup(indio_dev); - regulator_disable(st->vref); + if (st->vref) + regulator_disable(st->vref); regulator_disable(st->reg); kfree(st->rx_buf); @@ -872,7 +893,8 @@ static int __maybe_unused ad799x_suspend(struct device *dev) struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev)); struct ad799x_state *st = iio_priv(indio_dev); - regulator_disable(st->vref); + if (st->vref) + regulator_disable(st->vref); regulator_disable(st->reg); return 0; @@ -889,17 +911,21 @@ static int __maybe_unused ad799x_resume(struct device *dev) dev_err(dev, "Unable to enable vcc regulator\n"); return ret; } - ret = regulator_enable(st->vref); - if (ret) { - regulator_disable(st->reg); - dev_err(dev, "Unable to enable vref regulator\n"); - return ret; + + if (st->vref) { + ret = regulator_enable(st->vref); + if (ret) { + regulator_disable(st->reg); + dev_err(dev, "Unable to enable vref regulator\n"); + return ret; + } } /* resync config */ ret = ad799x_update_config(st, st->config); if (ret) { - regulator_disable(st->vref); + if (st->vref) + regulator_disable(st->vref); regulator_disable(st->reg); return ret; } -- 2.30.2