From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f67.google.com ([74.125.82.67]:36812 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754146AbeEOOnI (ORCPT ); Tue, 15 May 2018 10:43:08 -0400 Message-ID: <1526395385.32235.8.camel@gmail.com> Subject: Re: [PATCH] iio: dac: Add regulator framework to LTC2632 device driver From: Silvan Murer Date: Tue, 15 May 2018 16:43:05 +0200 In-Reply-To: <687efcfb-a9a8-99e7-8a81-150c3a4712a3@metafoo.de> References: <1526293892.12966.21.camel@gmail.com> <687efcfb-a9a8-99e7-8a81-150c3a4712a3@metafoo.de> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: devicetree-owner@vger.kernel.org To: Lars-Peter Clausen , Jonathan Cameron Cc: linux-iio@vger.kernel.org, devicetree@vger.kernel.org List-ID: Thanks Lars for the feedback. I created just now, a new patch which includes just the of_match_table fix. For the other stuffe i will create a new version of the patch (v2) soon.  On Mon, 2018-05-14 at 13:14 +0200, Lars-Peter Clausen wrote: > On 05/14/2018 12:31 PM, Silvan Murer wrote: > > > > This patch adds support for external reference voltage through the > > regulator framework. > > The patch add also the remove function to the device driver. > > > > Signed-off-by: Silvan Murer > Hi, > > Thanks for the patch. A few comments. > > > > > --- > >  .../devicetree/bindings/iio/dac/ltc2632.txt        |  9 +++ > >  drivers/iio/dac/ltc2632.c                          | 86 > > +++++++++++++++++----- > >  2 files changed, 78 insertions(+), 17 deletions(-) > > > > diff --git a/Documentation/devicetree/bindings/iio/dac/ltc2632.txt > > b/Documentation/devicetree/bindings/iio/dac/ltc2632.txt > > index eb911e5..d369a4b 100644 > > --- a/Documentation/devicetree/bindings/iio/dac/ltc2632.txt > > +++ b/Documentation/devicetree/bindings/iio/dac/ltc2632.txt > > @@ -14,10 +14,19 @@ apply. In particular, "reg" and "spi-max- > > frequency" properties must be given. > >   > >  Example: > >   > > + vref: regulator-vref { > > + compatible = "regulator-fixed"; > > + regulator-name = "vref-ltc2632"; > > + regulator-min-microvolt = <1250000>; > > + regulator-max-microvolt = <1250000>; > > + regulator-always-on; > > + }; > > + > >   spi_master { > >   dac: ltc2632@0 { > >   compatible = "lltc,ltc2632-l12"; > >   reg = <0>; /* CS0 */ > >   spi-max-frequency = <1000000>; > > + vref-supply = <&vref>; /* optional */ > This should not only update the example, but also add a 'optional > properties' section where the property is documented. > > > > >   }; > >   }; > > diff --git a/drivers/iio/dac/ltc2632.c b/drivers/iio/dac/ltc2632.c > > index ac5e05f..4a5c5bd 100644 > > --- a/drivers/iio/dac/ltc2632.c > > +++ b/drivers/iio/dac/ltc2632.c > [... > > > >  enum ltc2632_supported_device_ids { > > @@ -90,7 +96,7 @@ static int ltc2632_read_raw(struct iio_dev > > *indio_dev, > >   > >   switch (m) { > >   case IIO_CHAN_INFO_SCALE: > > - *val = chip_info->vref_mv; > > + *val = st->vref_mv; > >   *val2 = chan->scan_type.realbits; > >   return IIO_VAL_FRACTIONAL_LOG2; > >   } > > @@ -247,6 +253,41 @@ static int ltc2632_probe(struct spi_device > > *spi) > >   chip_info = (struct ltc2632_chip_info *) > >   spi_get_device_id(spi)->driver_data; > >   > > + st->vref_reg = devm_regulator_get_optional(&spi->dev, > > "vref"); > > + if (IS_ERR(st->vref_reg)) { > There are two error cases that should be handled. One is no regulator > is > specified and the other is a regulator is specified, but something > went > wrong. In the later case the error should be reported and not > ignored. Have > a look at e.g. ad5592r-base.c as an example. > > > > > + /* use internal reference voltage */ > > + st->vref_reg = NULL; > > + st->vref_mv = chip_info->vref_mv; > > + > > + ret = ltc2632_spi_write(spi, > > LTC2632_CMD_INTERNAL_REFER, > > + 0, 0, 0); > > + if (ret) { > > + dev_err(&spi->dev, > > + "Set internal reference command > > failed, %d\n", > > + ret); > > + return ret; > > + } > > + } else { > > + /* use external reference voltage */ > > + ret = regulator_enable(st->vref_reg); > > + if (ret) { > > + dev_err(&spi->dev, > > + "enable reference regulator > > failed, %d\n", > > + ret); > > + return ret; > > + } > > + st->vref_mv = regulator_get_voltage(st- > > >vref_reg)/1000; > Should be space around '/'. > > > > > + > > + ret = ltc2632_spi_write(spi, > > LTC2632_CMD_EXTERNAL_REFER, > > + 0, 0, 0); > > + if (ret) { > > + dev_err(&spi->dev, > > + "Set external reference command > > failed, %d\n", > > + ret); > > + return ret; > > + } > > + } > > + > >   indio_dev->dev.parent = &spi->dev; > >   indio_dev->name = dev_of_node(&spi->dev) ? > > dev_of_node(&spi->dev)->name > >    : > > spi_get_device_id(spi)->name; > > @@ -255,14 +296,23 @@ static int ltc2632_probe(struct spi_device > > *spi) > >   indio_dev->channels = chip_info->channels; > >   indio_dev->num_channels = LTC2632_DAC_CHANNELS; > >   > > - ret = ltc2632_spi_write(spi, LTC2632_CMD_INTERNAL_REFER, > > 0, 0, 0); > > - if (ret) { > > - dev_err(&spi->dev, > > - "Set internal reference command failed, > > %d\n", ret); > > - return ret; > > + return devm_iio_device_register(&spi->dev, indio_dev); > > +} > > + > > +static int ltc2632_remove(struct spi_device *spi) > > +{ > > + struct iio_dev *indio_dev = spi_get_drvdata(spi); > > + struct ltc2632_state *st = iio_priv(indio_dev); > > + > > + devm_iio_device_unregister(&spi->dev, indio_dev); > > + > > + if (st->vref_reg != NULL) { > > + regulator_disable(st->vref_reg); > > + devm_regulator_put(st->vref_reg); > >   } > >   > > - return devm_iio_device_register(&spi->dev, indio_dev); > > + devm_iio_device_free(&spi->dev, indio_dev); > The idea behind the devm_* interface is that you do not explicitly > call it > in the remove() callback. It will automatically run after the remove > function. > > This means in this case you can remove the devm_regulator_put() and > devm_iio_device_free(). > > The devm_iio_device_unregister() still needs to say since we have to > unregister the device before we disable the regulator. But you can > simplify > this by using the non-managed API > (iio_device_unregister()/iio_device_unregister()). > > > > > + return 0; > >  } > >   > >  static const struct spi_device_id ltc2632_id[] = { > > @@ -276,15 +326,6 @@ static const struct spi_device_id ltc2632_id[] > > = { > >  }; > >  MODULE_DEVICE_TABLE(spi, ltc2632_id); > >   > > -static struct spi_driver ltc2632_driver = { > > - .driver = { > > - .name = "ltc2632", > > - }, > > - .probe = ltc2632_probe, > > - .id_table = ltc2632_id, > > -}; > > -module_spi_driver(ltc2632_driver); > > - > >  static const struct of_device_id ltc2632_of_match[] = { > >   { > >   .compatible = "lltc,ltc2632-l12", > > @@ -309,6 +350,17 @@ static const struct of_device_id > > ltc2632_of_match[] = { > >  }; > >  MODULE_DEVICE_TABLE(of, ltc2632_of_match); > >   > > +static struct spi_driver ltc2632_driver = { > > + .driver = { > > + .name = "ltc2632", > > + .of_match_table = of_match_ptr(ltc2632_of_match), > It's a bit strange that of_match_table was not assigned in the first > place. > I think this should be a separate change and be declared as a fix. > > > > > + }, > > + .probe = ltc2632_probe, > > + .remove     = ltc2632_remove, > This line uses tabs for alignment, while all the other lines use > tabs. > > > > > + .id_table = ltc2632_id, > > +}; > > +module_spi_driver(ltc2632_driver);