On Mon, 21 May 2018 14:21:28 +0200
Silvan Murer <silvan.murer@xxxxxxxxx> wrote:
> Signed-off-by: Silvan Murer <silvan.murer@xxxxxxxxx>
> Reviewed-by: Lars-Peter Clausen <lars@xxxxxxxxxx>
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 <silvan.murer@xxxxxxxxx>
> *
> * Licensed under the GPL-2.
> */
> @@ -10,6 +11,7 @@
> #include <linux/spi/spi.h>
> #include <linux/module.h>
> #include <linux/iio/iio.h>
> +#include <linux/regulator/consumer.h>
>
> #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);
--
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