From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f68.google.com ([74.125.82.68]:35809 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754042AbeEWHT3 (ORCPT ); Wed, 23 May 2018 03:19:29 -0400 Message-ID: <1527059966.7868.5.camel@gmail.com> Subject: Re: [PATCH v4 2/2] iio: dac: Add support for external reference voltage through the regulator framework. From: Silvan Murer Date: Wed, 23 May 2018 09:19:26 +0200 In-Reply-To: <20180522182553.2b3ab124@archlinux> References: <1526905288-28668-1-git-send-email-silvan.murer@gmail.com> <1526905288-28668-3-git-send-email-silvan.murer@gmail.com> <20180522182553.2b3ab124@archlinux> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: devicetree-owner@vger.kernel.org To: Jonathan Cameron Cc: lars@metafoo.de, linux-iio@vger.kernel.org, devicetree@vger.kernel.org List-ID: Thank you Jonathan On Die, 2018-05-22 at 18:25 +0100, Jonathan Cameron wrote: > On Mon, 21 May 2018 14:21:28 +0200 > Silvan Murer wrote: > > > > > Signed-off-by: Silvan Murer > > Reviewed-by: Lars-Peter Clausen > Applied to the togreg branch of iio.git and pushed out as testing > for the autobuilders to play with it. > > Thanks, > > Jonathan > > > > > --- > >  .../devicetree/bindings/iio/dac/ltc2632.txt        | 14 +++++ > >  drivers/iio/dac/ltc2632.c                          | 70 > > +++++++++++++++++++--- > >  2 files changed, 75 insertions(+), 9 deletions(-) > > > > diff --git a/Documentation/devicetree/bindings/iio/dac/ltc2632.txt > > b/Documentation/devicetree/bindings/iio/dac/ltc2632.txt > > index eb911e5..e0d5fea 100644 > > --- a/Documentation/devicetree/bindings/iio/dac/ltc2632.txt > > +++ b/Documentation/devicetree/bindings/iio/dac/ltc2632.txt > > @@ -12,12 +12,26 @@ Required properties: > >  Property rules described in > > Documentation/devicetree/bindings/spi/spi-bus.txt > >  apply. In particular, "reg" and "spi-max-frequency" properties > > must be given. > >   > > +Optional properties: > > + - vref-supply: Phandle to the external reference voltage > > supply. This should > > +   only be set if there is an external reference voltage > > connected to the VREF > > +   pin. If the property is not set the internal reference > > is used. > > + > >  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 */ > >   }; > >   }; > > diff --git a/drivers/iio/dac/ltc2632.c b/drivers/iio/dac/ltc2632.c > > index d322b78..9551156 100644 > > --- a/drivers/iio/dac/ltc2632.c > > +++ b/drivers/iio/dac/ltc2632.c > > @@ -2,6 +2,7 @@ > >   * LTC2632 Digital to analog convertors spi driver > >   * > >   * Copyright 2017 Maxime Roussin-B_langer > > + * expanded by Silvan Murer > >   * > >   * Licensed under the GPL-2. > >   */ > > @@ -10,6 +11,7 @@ > >  #include > >  #include > >  #include > > +#include > >   > >  #define LTC2632_DAC_CHANNELS                    2 > >   > > @@ -28,7 +30,7 @@ > >  /** > >   * struct ltc2632_chip_info - chip specific information > >   * @channels: channel spec for the DAC > > - * @vref_mv: reference voltage > > + * @vref_mv: internal reference voltage > >   */ > >  struct ltc2632_chip_info { > >   const struct iio_chan_spec *channels; > > @@ -39,10 +41,14 @@ struct ltc2632_chip_info { > >   * struct ltc2632_state - driver instance specific data > >   * @spi_dev: pointer to the spi_device > > struct > >   * @powerdown_cache_mask used to show current channel > > powerdown state > > + * @vref_mv used reference voltage > > (internal or external) > > + * @vref_reg regulator for the reference voltage > >   */ > >  struct ltc2632_state { > >   struct spi_device *spi_dev; > >   unsigned int powerdown_cache_mask; > > + int vref_mv; > > + struct regulator *vref_reg; > >  }; > >   > >  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 +253,45 @@ 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 (PTR_ERR(st->vref_reg) == -ENODEV) { > > + /* 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 if (IS_ERR(st->vref_reg)) { > > + dev_err(&spi->dev, > > + "Error getting voltage reference > > regulator\n"); > > + return PTR_ERR(st->vref_reg); > > + } 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; > > + > > + 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 +300,20 @@ 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 iio_device_register(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); > > + > > + iio_device_unregister(indio_dev); > > + > > + if (st->vref_reg) > > + regulator_disable(st->vref_reg); > >   > > - return devm_iio_device_register(&spi->dev, indio_dev); > > + return 0; > >  } > >   > >  static const struct spi_device_id ltc2632_id[] = { > > @@ -306,6 +357,7 @@ static struct spi_driver ltc2632_driver = { > >   .of_match_table = of_match_ptr(ltc2632_of_match), > >   }, > >   .probe = ltc2632_probe, > > + .remove = ltc2632_remove, > >   .id_table = ltc2632_id, > >  }; > >  module_spi_driver(ltc2632_driver);