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SubjectRe: [PATCH v5 3/5] iio: amplifiers: hmc425a: Add support for HMC425A attenuator
Date
Hi,

I checked the modifications and everything works as expected.

Thanks,
Ben
On Fri, 2020-02-14 at 14:09 +0000, Jonathan Cameron wrote:
> [External]
>
> On Thu, 6 Feb 2020 17:11:47 +0200
> Beniamin Bia <beniamin.bia@analog.com> wrote:
>
> > This patch adds support for the HMC425A 0.5 dB LSB GaAs MMIC 6-BIT
> > DIGITAL POSITIVE CONTROL ATTENUATOR, 2.2 - 8.0 GHz.
> >
> > Datasheet:
> >
https://www.analog.com/media/en/technical-documentation/data-sheets/hmc425A.pdf
> >
> > Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
> > Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
> > Signed-off-by: Beniamin Bia <beniamin.bia@analog.com>
>
> 2 things left in here. I'll have a go at fixing them up to save us
> going
> to v6 but please take a look at the result and check I haven't broken
> anything!
>
> Applied to the togreg branch of iio.git and pushed out as testing for
> the autobuilders to have a play with it.
>
> Thanks,
>
> Jonathan
>
> > ---
> > Changes in v5:
> > -properties in HMC425A_CHAN on separate lines
> > -of_device_get_match instead of of_match_device
> >
> > drivers/iio/amplifiers/Kconfig | 10 ++
> > drivers/iio/amplifiers/Makefile | 1 +
> > drivers/iio/amplifiers/hmc425a.c | 253
> > +++++++++++++++++++++++++++++++
> > 3 files changed, 264 insertions(+)
> > create mode 100644 drivers/iio/amplifiers/hmc425a.c
> >
> > diff --git a/drivers/iio/amplifiers/Kconfig
> > b/drivers/iio/amplifiers/Kconfig
> > index da7f126d197b..9b02c9a2bc8a 100644
> > --- a/drivers/iio/amplifiers/Kconfig
> > +++ b/drivers/iio/amplifiers/Kconfig
> > @@ -22,4 +22,14 @@ config AD8366
> > To compile this driver as a module, choose M here: the
> > module will be called ad8366.
> >
> > +config HMC425
> > + tristate "Analog Devices HMC425A and similar GPIO Gain
> > Amplifiers"
> > + depends on GPIOLIB
> > + help
> > + Say yes here to build support for Analog Devices HMC425A and
> > similar
> > + gain amplifiers or step attenuators.
> > +
> > + To compile this driver as a module, choose M here: the
> > + module will be called hmc425a.
> > +
> > endmenu
> > diff --git a/drivers/iio/amplifiers/Makefile
> > b/drivers/iio/amplifiers/Makefile
> > index 9abef2ebe9bc..19a89db1d9b1 100644
> > --- a/drivers/iio/amplifiers/Makefile
> > +++ b/drivers/iio/amplifiers/Makefile
> > @@ -5,3 +5,4 @@
> >
> > # When adding new entries keep the list in alphabetical order
> > obj-$(CONFIG_AD8366) += ad8366.o
> > +obj-$(CONFIG_HMC425) += hmc425a.o
> > \ No newline at end of file
>
> I'll fix the no newline..
>
> > diff --git a/drivers/iio/amplifiers/hmc425a.c
> > b/drivers/iio/amplifiers/hmc425a.c
> > new file mode 100644
> > index 000000000000..b0d624a7ad05
> > --- /dev/null
> > +++ b/drivers/iio/amplifiers/hmc425a.c
> > @@ -0,0 +1,253 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * HMC425A and similar Gain Amplifiers
> > + *
> > + * Copyright 2020 Analog Devices Inc.
> > + */
> > +
> > +#include <linux/device.h>
> > +#include <linux/err.h>
> > +#include <linux/gpio/consumer.h>
> > +#include <linux/iio/iio.h>
> > +#include <linux/iio/sysfs.h>
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/of_device.h>
> > +#include <linux/of_platform.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/slab.h>
> > +#include <linux/regulator/consumer.h>
> > +#include <linux/sysfs.h>
> > +
> > +enum hmc425a_type {
> > + ID_HMC425A,
> > +};
> > +
> > +struct hmc425a_chip_info {
> > + const char *name;
> > + const struct iio_chan_spec *channels;
> > + unsigned int num_channels;
> > + unsigned int num_gpios;
> > + int gain_min;
> > + int gain_max;
> > + int default_gain;
> > +};
> > +
> > +struct hmc425a_state {
> > + struct regulator *reg;
> > + struct mutex lock; /* protect sensor state */
> > + struct hmc425a_chip_info *chip_info;
> > + struct gpio_descs *gpios;
> > + enum hmc425a_type type;
> > + u32 gain;
> > +};
> > +
> > +static int hmc425a_write(struct iio_dev *indio_dev, u32 value)
> > +{
> > + struct hmc425a_state *st = iio_priv(indio_dev);
> > + DECLARE_BITMAP(values, BITS_PER_TYPE(value));
> > +
> > + values[0] = value;
> > +
> > + gpiod_set_array_value_cansleep(st->gpios->ndescs, st->gpios-
> > >desc,
> > + NULL, values);
> > + return 0;
> > +}
> > +
> > +static int hmc425a_read_raw(struct iio_dev *indio_dev,
> > + struct iio_chan_spec const *chan, int *val,
> > + int *val2, long m)
> > +{
> > + struct hmc425a_state *st = iio_priv(indio_dev);
> > + int code, gain = 0;
> > + int ret;
> > +
> > + mutex_lock(&st->lock);
> > + switch (m) {
> > + case IIO_CHAN_INFO_HARDWAREGAIN:
> > + code = st->gain;
> > +
> > + switch (st->type) {
> > + case ID_HMC425A:
> > + gain = ~code * -500;
> > + break;
> > + }
> > +
> > + *val = gain / 1000;
> > + *val2 = (gain % 1000) * 1000;
> > +
> > + ret = IIO_VAL_INT_PLUS_MICRO_DB;
> > + break;
> > + default:
> > + ret = -EINVAL;
> > + }
> > + mutex_unlock(&st->lock);
> > +
> > + return ret;
> > +};
> > +
> > +static int hmc425a_write_raw(struct iio_dev *indio_dev,
> > + struct iio_chan_spec const *chan, int val,
> > + int val2, long mask)
> > +{
> > + struct hmc425a_state *st = iio_priv(indio_dev);
> > + struct hmc425a_chip_info *inf = st->chip_info;
> > + int code = 0, gain;
> > + int ret;
> > +
> > + if (val < 0)
> > + gain = (val * 1000) - (val2 / 1000);
> > + else
> > + gain = (val * 1000) + (val2 / 1000);
> > +
> > + if (gain > inf->gain_max || gain < inf->gain_min)
> > + return -EINVAL;
> > +
> > + switch (st->type) {
> > + case ID_HMC425A:
> > + code = ~((abs(gain) / 500) & 0x3F);
> > + break;
> > + }
> > +
> > + mutex_lock(&st->lock);
> > + switch (mask) {
> > + case IIO_CHAN_INFO_HARDWAREGAIN:
> > + st->gain = code;
> > +
> > + ret = hmc425a_write(indio_dev, st->gain);
> > + break;
> > + default:
> > + ret = -EINVAL;
> > + }
> > + mutex_unlock(&st->lock);
> > +
> > + return ret;
> > +}
> > +
> > +static int hmc425a_write_raw_get_fmt(struct iio_dev *indio_dev,
> > + struct iio_chan_spec const *chan,
> > + long mask)
> > +{
> > + switch (mask) {
> > + case IIO_CHAN_INFO_HARDWAREGAIN:
> > + return IIO_VAL_INT_PLUS_MICRO_DB;
> > + default:
> > + return -EINVAL;
> > + }
> > +}
> > +
> > +static const struct iio_info hmc425a_info = {
> > + .read_raw = &hmc425a_read_raw,
> > + .write_raw = &hmc425a_write_raw,
> > + .write_raw_get_fmt = &hmc425a_write_raw_get_fmt,
> > +};
> > +
> > +#define HMC425A_CHAN(_channel)
> > \
> > +{
> > \
> > + .type = IIO_VOLTAGE,
> > \
> > + .output = 1,
> > \
> > + .indexed = 1,
> > \
> > + .channel = _channel,
> > \
> > + .info_mask_separate = BIT(IIO_CHAN_INFO_HARDWAREGAIN),
> > \
> > +}
> > +
> > +static const struct iio_chan_spec hmc425a_channels[] = {
> > + HMC425A_CHAN(0),
> > +};
> > +
> > +/* Match table for of_platform binding */
> > +static const struct of_device_id hmc425a_of_match[] = {
> > + { .compatible = "adi,hmc425a", .data = (void *)ID_HMC425A },
> > + {},
> > +};
> > +MODULE_DEVICE_TABLE(of, hmc425a_of_match);
> > +
> > +static void hmc425a_reg_disable(void *data)
> > +{
> > + struct hmc425a_state *st = data;
> > +
> > + regulator_disable(st->reg);
> > +}
> > +
> > +static struct hmc425a_chip_info hmc425a_chip_info_tbl[] = {
> > + [ID_HMC425A] = {
> > + .name = "hmc425a",
> > + .channels = hmc425a_channels,
> > + .num_channels = ARRAY_SIZE(hmc425a_channels),
> > + .num_gpios = 6,
> > + .gain_min = -31500,
> > + .gain_max = 0,
> > + .default_gain = -0x40, /* set default gain -31.5db*/
> > + },
> > +};
> > +
> > +static int hmc425a_probe(struct platform_device *pdev)
> > +{
> > + struct iio_dev *indio_dev;
> > + struct hmc425a_state *st;
> > + int ret;
> > +
> > + indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*st));
> > + if (!indio_dev)
> > + return -ENOMEM;
> > +
> > + st = iio_priv(indio_dev);
> > + st->type = (enum hmc425a_type)of_device_get_match_data(&pdev-
> > >dev);
> > +
> > + st->chip_info = &hmc425a_chip_info_tbl[st->type];
> > + indio_dev->num_channels = st->chip_info->num_channels;
> > + indio_dev->channels = st->chip_info->channels;
> > + indio_dev->name = st->chip_info->name;
> > + st->gain = st->chip_info->default_gain;
> > +
> > + st->gpios = devm_gpiod_get_array(&pdev->dev, "ctrl",
> > GPIOD_OUT_LOW);
> > + if (IS_ERR(st->gpios)) {
> > + ret = PTR_ERR(st->gpios);
> > + if (ret != -EPROBE_DEFER)
> > + dev_err(&pdev->dev, "failed to get gpios\n");
> > + return ret;
> > + }
> > +
> > + if (st->gpios->ndescs != st->chip_info->num_gpios) {
> > + dev_err(&pdev->dev, "%d GPIOs needed to operate\n",
> > + st->chip_info->num_gpios);
> > + return -ENODEV;
> > + }
> > +
> > + st->reg = devm_regulator_get_optional(&pdev->dev, "vcc-
> > supply");
> Sorry I'd missed this before. Why is this optional? I think
> what is needed here is to just let the regulator framework provide
> a stub if no regulator is supplied in DT.
>
> We only play this optional game if we have regulators that are really
> optional such as reference voltages on parts that also have internal
> references that can be used.
>
> > + 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;
> > + ret = devm_add_action_or_reset(&pdev->dev,
> > hmc425a_reg_disable,
> > + st);
> > + if (ret)
> > + return ret;
> > + }
> > +
> > + mutex_init(&st->lock);
> > +
> > + indio_dev->dev.parent = &pdev->dev;
> > + indio_dev->info = &hmc425a_info;
> > + indio_dev->modes = INDIO_DIRECT_MODE;
> > +
> > + return devm_iio_device_register(&pdev->dev, indio_dev);
> > +}
> > +
> > +static struct platform_driver hmc425a_driver = {
> > + .driver = {
> > + .name = KBUILD_MODNAME,
> > + .of_match_table = hmc425a_of_match,
> > + },
> > + .probe = hmc425a_probe,
> > +};
> > +module_platform_driver(hmc425a_driver);
> > +
> > +MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
> > +MODULE_DESCRIPTION("Analog Devices HMC425A and similar GPIO
> > control Gain Amplifiers");
> > +MODULE_LICENSE("GPL v2");
>
>
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