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Message-ID: <20191021155450.0ac9d380@archlinux>
Date: Mon, 21 Oct 2019 15:54:50 +0100
From: Jonathan Cameron <jic23@...nel.org>
To: Beniamin Bia <beniamin.bia@...log.com>
Cc: <lars@...afoo.de>, <Michael.Hennerich@...log.com>,
<knaack.h@....de>, <pmeerw@...erw.net>,
<gregkh@...uxfoundation.org>, <linux-iio@...r.kernel.org>,
<devel@...verdev.osuosl.org>, <linux-kernel@...r.kernel.org>,
<mark.rutland@....com>, <robh+dt@...nel.org>,
<devicetree@...r.kernel.org>, <paulmck@...ux.ibm.com>,
<mchehab+samsung@...nel.org>, <linus.walleij@...aro.org>,
<nicolas.ferre@...rochip.com>, <biabeniamin@...look.com>,
Paul Cercueil <paul.cercueil@...log.com>
Subject: Re: [PATCH 2/4] iio: adc: ad7091r5: Add scale and external VREF
support
On Mon, 21 Oct 2019 20:06:06 +0300
Beniamin Bia <beniamin.bia@...log.com> wrote:
> From: Paul Cercueil <paul.cercueil@...log.com>
>
> The scale can now be obtained with the "in_voltage_scale" file.
> By default, the scale returned corresponds to the internal VREF of 2.5V.
>
> It is possible to use an external VREF (through the REFIN/REFOUT pin of
> the chip), by passing a regulator to the driver. The scale will then be
> calculated according to the voltage reported by the regulator.
>
> Signed-off-by: Paul Cercueil <paul.cercueil@...log.com>
> Co-developed-by: Beniamin Bia <beniamin.bia@...log.com>
> Signed-off-by: Beniamin Bia <beniamin.bia@...log.com>
My only comment on this one is that you could use devm_add_action_or_reset
to deal with the regulator clean up.
> ---
> drivers/iio/adc/ad7091r-base.c | 42 +++++++++++++++++++++++++++++++++-
> drivers/iio/adc/ad7091r-base.h | 1 +
> drivers/iio/adc/ad7091r5.c | 5 ++++
> 3 files changed, 47 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/iio/adc/ad7091r-base.c b/drivers/iio/adc/ad7091r-base.c
> index 140413329754..d416f0912531 100644
> --- a/drivers/iio/adc/ad7091r-base.c
> +++ b/drivers/iio/adc/ad7091r-base.c
> @@ -14,6 +14,7 @@
> #include <linux/interrupt.h>
> #include <linux/module.h>
> #include <linux/regmap.h>
> +#include <linux/regulator/consumer.h>
>
> #define AD7091R_REG_RESULT 0
> #define AD7091R_REG_CHANNEL 1
> @@ -42,6 +43,7 @@ enum ad7091r_mode {
> struct ad7091r_state {
> struct device *dev;
> struct regmap *map;
> + struct regulator *reg;
> const struct ad7091r_chip_info *chip_info;
> enum ad7091r_mode mode;
> };
> @@ -139,6 +141,21 @@ static int ad7091r_read_raw(struct iio_dev *iio_dev,
> ret = IIO_VAL_INT;
> break;
>
> + case IIO_CHAN_INFO_SCALE:
> + if (st->reg) {
> + ret = regulator_get_voltage(st->reg);
> + if (ret < 0)
> + goto unlock;
> +
> + *val = ret / 1000;
> + } else {
> + *val = st->chip_info->vref_mV;
> + }
> +
> + *val2 = chan->scan_type.realbits;
> + ret = IIO_VAL_FRACTIONAL_LOG2;
> + break;
> +
> default:
> ret = -EINVAL;
> break;
> @@ -215,6 +232,18 @@ int ad7091r_probe(struct device *dev, const char *name,
> return ret;
> }
>
> + st->reg = devm_regulator_get_optional(dev, "vref");
> + if (IS_ERR(st->reg)) {
> + if (PTR_ERR(st->reg) == EPROBE_DEFER)
> + return -EPROBE_DEFER;
> +
> + st->reg = NULL;
> + } else {
> + ret = regulator_enable(st->reg);
> + if (ret)
> + return ret;
I would use devm_add_action_or_reset with appropriate wrapper
around disabling the regulator. That will get rid of the
need to manually deal with errors or remove path.
> + }
> +
> /* Use command mode by default */
> ret = ad7091r_set_mode(st, AD7091R_MODE_COMMAND);
> if (ret < 0)
> @@ -222,18 +251,29 @@ int ad7091r_probe(struct device *dev, const char *name,
>
> ret = iio_device_register(iio_dev);
> if (ret)
> - return ret;
> + goto err_disable_reg;
>
> dev_dbg(dev, "Probed\n");
> return 0;
> +
> +err_disable_reg:
> + if (st->reg)
> + regulator_disable(st->reg);
> +
> + return ret;
> }
> EXPORT_SYMBOL_GPL(ad7091r_probe);
>
> int ad7091r_remove(struct device *dev)
> {
> struct iio_dev *iio_dev = dev_get_drvdata(dev);
> + struct ad7091r_state *st = iio_priv(iio_dev);
>
> iio_device_unregister(iio_dev);
> +
> + if (st->reg)
> + regulator_disable(st->reg);
> +
> return 0;
> }
> EXPORT_SYMBOL_GPL(ad7091r_remove);
> diff --git a/drivers/iio/adc/ad7091r-base.h b/drivers/iio/adc/ad7091r-base.h
> index 7a29f86ea82b..cec4fb75fecc 100644
> --- a/drivers/iio/adc/ad7091r-base.h
> +++ b/drivers/iio/adc/ad7091r-base.h
> @@ -18,6 +18,7 @@ struct ad7091r_state;
> struct ad7091r_chip_info {
> unsigned int num_channels;
> const struct iio_chan_spec *channels;
> + unsigned int vref_mV;
> };
>
> extern const struct regmap_config ad7091r_regmap_config;
> diff --git a/drivers/iio/adc/ad7091r5.c b/drivers/iio/adc/ad7091r5.c
> index 1ba838c58c31..65bcd8bb692a 100644
> --- a/drivers/iio/adc/ad7091r5.c
> +++ b/drivers/iio/adc/ad7091r5.c
> @@ -35,10 +35,13 @@ static const struct iio_event_spec ad7091r5_events[] = {
> #define AD7091R_CHANNEL(idx, bits, ev, num_ev) { \
> .type = IIO_VOLTAGE, \
> .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
> + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
> .indexed = 1, \
> .channel = idx, \
> .event_spec = ev, \
> .num_event_specs = num_ev, \
> + .scan_type.storagebits = 16, \
> + .scan_type.realbits = bits, \
> }
> static const struct iio_chan_spec ad7091r5_channels_irq[] = {
> AD7091R_CHANNEL(0, 12, ad7091r5_events, ARRAY_SIZE(ad7091r5_events)),
> @@ -58,11 +61,13 @@ static const struct iio_chan_spec ad7091r5_channels_noirq[] = {
> static const struct ad7091r_chip_info ad7091r5_chip_info_irq = {
> .channels = ad7091r5_channels_irq,
> .num_channels = ARRAY_SIZE(ad7091r5_channels_irq),
> + .vref_mV = 2500,
> };
>
> static const struct ad7091r_chip_info ad7091r5_chip_info_noirq = {
> .channels = ad7091r5_channels_noirq,
> .num_channels = ARRAY_SIZE(ad7091r5_channels_noirq),
> + .vref_mV = 2500,
> };
>
> static int ad7091r5_i2c_probe(struct i2c_client *i2c,
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