From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753162AbcGSIOD (ORCPT ); Tue, 19 Jul 2016 04:14:03 -0400 Received: from mail2.openmailbox.org ([62.4.1.33]:47068 "EHLO mail2.openmailbox.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753047AbcGSIN4 (ORCPT ); Tue, 19 Jul 2016 04:13:56 -0400 From: =?UTF-8?q?Pawe=C5=82=20Grudzi=C5=84ski?= To: Lars-Peter Clausen , Michael Hennerich , Jonathan Cameron , Hartmut Knaack , Peter Meerwald , linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Pawel Grudzinski Subject: [PATCH v2] iio: dac: ad5380: Fix probe failure when no external reference is supplied Date: Tue, 19 Jul 2016 08:12:45 +0200 Message-Id: <20160719061302.8360-1-pgrudzinski@openmailbox.org> X-Mailer: git-send-email 2.8.3 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Pawel Grudzinski Driver fails to load when there is no external Vref regulator defined, leaving no way to use internal reference. ad5380_probe function tries to obtain regulator with demv_regulator_get and checks for error, in which case it would use internal reference. Even without "Vref" regulator defined devm_regulator_get returns dummy regulator which makes function omit use of internal reference and causes failure on regulator_get_voltage. Replace demv_regulator_get with demv_regulator_get_optional, which returns error instead of dummy regulator if it does not find one which is specified by the caller to make ad5380_probe configure internal reference when no "Vref" regulator is supplied. Initialize internal regulator only if returned error is ENODEV, otherwise propagate the error to the caller of probe. Signed-off-by: Paweł Grudziński --- Changes in v2: - Add error type checking to enable internal reference only on ENODEV and return any other error to the caller. drivers/iio/dac/ad5380.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/iio/dac/ad5380.c b/drivers/iio/dac/ad5380.c index 97d2c51..144cfdc 100644 --- a/drivers/iio/dac/ad5380.c +++ b/drivers/iio/dac/ad5380.c @@ -401,7 +401,7 @@ static int ad5380_probe(struct device *dev, struct regmap *regmap, if (st->chip_info->int_vref == 2500) ctrl |= AD5380_CTRL_INT_VREF_2V5; - st->vref_reg = devm_regulator_get(dev, "vref"); + st->vref_reg = devm_regulator_get_optional(dev, "vref"); if (!IS_ERR(st->vref_reg)) { ret = regulator_enable(st->vref_reg); if (ret) { @@ -416,8 +416,13 @@ static int ad5380_probe(struct device *dev, struct regmap *regmap, st->vref = ret / 1000; } else { - st->vref = st->chip_info->int_vref; - ctrl |= AD5380_CTRL_INT_VREF_EN; + if (PTR_ERR(st->vref_reg) == -ENODEV) { + st->vref = st->chip_info->int_vref; + ctrl |= AD5380_CTRL_INT_VREF_EN; + } else { + ret = st->vref_reg; + goto error_free_reg; + } } ret = regmap_write(st->regmap, AD5380_REG_SF_CTRL, ctrl); -- 2.8.0