LinuxLists.cc - [PATCH v3 1/2] dt-bindings: iio: frequency: add admfm2000

2023-11-22 10:59:49

Subject: [PATCH v3 1/2] dt-bindings: iio: frequency: add admfm2000

2023-11-22 11:00:04

Subject: [PATCH v3 2/2] iio: frequency: admfm2000: New driver

Dual microwave down converter module with input RF and LO frequency
ranges from 0.5 to 32 GHz and an output IF frequency range from 0.1 to
8 GHz. It consists of a LNA, mixer, IF filter, DSA, and IF amplifier
for each down conversion path.

Signed-off-by: Kim Seer Paller <[email protected]>
---
V1 -> V3: No changes.

MAINTAINERS | 1 +
drivers/iio/frequency/Kconfig | 10 +
drivers/iio/frequency/Makefile | 1 +
drivers/iio/frequency/admfm2000.c | 309 ++++++++++++++++++++++++++++++
4 files changed, 321 insertions(+)
create mode 100644 drivers/iio/frequency/admfm2000.c

diff --git a/MAINTAINERS b/MAINTAINERS
index f1692ec68..d8630e490 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1253,6 +1253,7 @@ L: [email protected]
S: Supported
W: https://ez.analog.com/linux-software-drivers
F: Documentation/devicetree/bindings/iio/frequency/adi,admfm2000.yaml
+F: drivers/iio/frequency/admfm2000.c

ANALOG DEVICES INC ADMV1013 DRIVER
M: Antoniu Miclaus <[email protected]>
diff --git a/drivers/iio/frequency/Kconfig b/drivers/iio/frequency/Kconfig
index 9e85dfa58..c455be7d4 100644
--- a/drivers/iio/frequency/Kconfig
+++ b/drivers/iio/frequency/Kconfig
@@ -60,6 +60,16 @@ config ADF4377
To compile this driver as a module, choose M here: the
module will be called adf4377.

+config ADMFM2000
+ tristate "Analog Devices ADMFM2000 Dual Microwave Down Converter"
+ depends on GPIOLIB
+ help
+ Say yes here to build support for Analog Devices ADMFM2000 Dual
+ Microwave Down Converter.
+
+ To compile this driver as a module, choose M here: the
+ module will be called admfm2000.
+
config ADMV1013
tristate "Analog Devices ADMV1013 Microwave Upconverter"
depends on SPI && COMMON_CLK
diff --git a/drivers/iio/frequency/Makefile b/drivers/iio/frequency/Makefile
index b616c29b4..70d0e0b70 100644
--- a/drivers/iio/frequency/Makefile
+++ b/drivers/iio/frequency/Makefile
@@ -8,6 +8,7 @@ obj-$(CONFIG_AD9523) += ad9523.o
obj-$(CONFIG_ADF4350) += adf4350.o
obj-$(CONFIG_ADF4371) += adf4371.o
obj-$(CONFIG_ADF4377) += adf4377.o
+obj-$(CONFIG_ADMFM2000) += admfm2000.o
obj-$(CONFIG_ADMV1013) += admv1013.o
obj-$(CONFIG_ADMV1014) += admv1014.o
obj-$(CONFIG_ADMV4420) += admv4420.o
diff --git a/drivers/iio/frequency/admfm2000.c b/drivers/iio/frequency/admfm2000.c
new file mode 100644
index 000000000..e0b5edce7
--- /dev/null
+++ b/drivers/iio/frequency/admfm2000.c
@@ -0,0 +1,309 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ADMFM2000 Dual Microwave Down Converter
+ *
+ * Copyright 2023 Analog Devices Inc.
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
+#include <linux/iio/iio.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+
+#define ADMFM2000_MIXER_MODE 0
+#define ADMFM2000_DIRECT_IF_MODE 1
+#define ADMF20000_DSA_GPIOS 5
+#define ADMF20000_MODE_GPIOS 2
+#define ADMF20000_MAX_GAIN 0
+#define ADMF20000_MIN_GAIN -31000
+#define ADMF20000_DEFAULT_GAIN -0x20
+
+struct admfm2000_state {
+ struct mutex lock; /* protect sensor state */
+ struct gpio_descs *sw_ch[2];
+ struct gpio_descs *dsa_gpios[2];
+ u32 gain[2];
+};
+
+static int admfm2000_mode(struct iio_dev *indio_dev, u32 reg, u32 mode)
+{
+ struct admfm2000_state *st = iio_priv(indio_dev);
+ DECLARE_BITMAP(values, 2);
+
+ switch (mode) {
+ case ADMFM2000_MIXER_MODE:
+ values[0] = (reg == 0) ? 1 : 2;
+ gpiod_set_array_value_cansleep(st->sw_ch[reg]->ndescs,
+ st->sw_ch[reg]->desc,
+ NULL, values);
+ break;
+ case ADMFM2000_DIRECT_IF_MODE:
+ values[0] = (reg == 0) ? 2 : 1;
+ gpiod_set_array_value_cansleep(st->sw_ch[reg]->ndescs,
+ st->sw_ch[reg]->desc,
+ NULL, values);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int admfm2000_attenuation(struct iio_dev *indio_dev, u32 chan,
+ u32 value)
+{
+ struct admfm2000_state *st = iio_priv(indio_dev);
+ DECLARE_BITMAP(values, BITS_PER_TYPE(value));
+
+ values[0] = value;
+
+ gpiod_set_array_value_cansleep(st->dsa_gpios[chan]->ndescs,
+ st->dsa_gpios[chan]->desc,
+ NULL, values);
+ return 0;
+}
+
+static int admfm2000_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val,
+ int *val2, long mask)
+{
+ struct admfm2000_state *st = iio_priv(indio_dev);
+ int gain;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_HARDWAREGAIN:
+ mutex_lock(&st->lock);
+ gain = ~(st->gain[chan->channel]) * -1000;
+ *val = gain / 1000;
+ *val2 = (gain % 1000) * 1000;
+ mutex_unlock(&st->lock);
+
+ return IIO_VAL_INT_PLUS_MICRO_DB;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int admfm2000_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int val,
+ int val2, long mask)
+{
+ struct admfm2000_state *st = iio_priv(indio_dev);
+ int gain, ret;
+
+ if (val < 0)
+ gain = (val * 1000) - (val2 / 1000);
+ else
+ gain = (val * 1000) + (val2 / 1000);
+
+ if (gain > ADMF20000_MAX_GAIN || gain < ADMF20000_MIN_GAIN)
+ return -EINVAL;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_HARDWAREGAIN:
+ mutex_lock(&st->lock);
+ st->gain[chan->channel] = ~((abs(gain) / 1000) & 0x1F);
+
+ ret = admfm2000_attenuation(indio_dev, chan->channel,
+ st->gain[chan->channel]);
+
+ mutex_unlock(&st->lock);
+ if (ret)
+ return ret;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int admfm2000_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 admfm2000_info = {
+ .read_raw = &admfm2000_read_raw,
+ .write_raw = &admfm2000_write_raw,
+ .write_raw_get_fmt = &admfm2000_write_raw_get_fmt,
+};
+
+#define ADMFM2000_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 admfm2000_channels[] = {
+ ADMFM2000_CHAN(0),
+ ADMFM2000_CHAN(1),
+};
+
+static int admfm2000_channel_config(struct admfm2000_state *st,
+ struct iio_dev *indio_dev)
+{
+ struct platform_device *pdev = to_platform_device(indio_dev->dev.parent);
+ struct device *dev = &pdev->dev;
+ struct fwnode_handle *child;
+ u32 reg, mode;
+ int ret;
+
+ device_for_each_child_node(dev, child) {
+ ret = fwnode_property_read_u32(child, "reg", &reg);
+ if (ret) {
+ fwnode_handle_put(child);
+ return dev_err_probe(dev, ret,
+ "Failed to get reg property\n");
+ }
+
+ if (reg >= indio_dev->num_channels) {
+ fwnode_handle_put(child);
+ return dev_err_probe(dev, -EINVAL, "reg bigger than: %d\n",
+ indio_dev->num_channels);
+ }
+
+ ret = fwnode_property_read_u32(child, "adi,mode", &mode);
+ if (ret) {
+ fwnode_handle_put(child);
+ return dev_err_probe(dev, ret,
+ "Failed to get mode property\n");
+ }
+
+ if (mode >= 2) {
+ fwnode_handle_put(child);
+ return dev_err_probe(dev, -EINVAL, "mode bigger than: 1\n");
+ }
+
+ ret = admfm2000_mode(indio_dev, reg, mode);
+ if (ret) {
+ fwnode_handle_put(child);
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+static int admfm2000_setup(struct admfm2000_state *st,
+ struct iio_dev *indio_dev)
+{
+ struct platform_device *pdev = to_platform_device(indio_dev->dev.parent);
+ struct device *dev = &pdev->dev;
+
+ st->sw_ch[0] = devm_gpiod_get_array(dev, "switch1", GPIOD_OUT_LOW);
+ if (IS_ERR(st->sw_ch[0]))
+ return dev_err_probe(dev, PTR_ERR(st->sw_ch[0]),
+ "Failed to get gpios\n");
+
+ if (st->sw_ch[0]->ndescs != ADMF20000_MODE_GPIOS) {
+ dev_err_probe(dev, -ENODEV, "%d GPIOs needed to operate\n",
+ ADMF20000_MODE_GPIOS);
+ return -ENODEV;
+ }
+
+ st->sw_ch[1] = devm_gpiod_get_array(dev, "switch2", GPIOD_OUT_LOW);
+ if (IS_ERR(st->sw_ch[1]))
+ return dev_err_probe(dev, PTR_ERR(st->sw_ch[1]),
+ "Failed to get gpios\n");
+
+ if (st->sw_ch[1]->ndescs != ADMF20000_MODE_GPIOS) {
+ dev_err_probe(dev, -ENODEV, "%d GPIOs needed to operate\n",
+ ADMF20000_MODE_GPIOS);
+ return -ENODEV;
+ }
+
+ st->dsa_gpios[0] = devm_gpiod_get_array(dev, "attenuation1",
+ GPIOD_OUT_LOW);
+ if (IS_ERR(st->dsa_gpios[0]))
+ return dev_err_probe(dev, PTR_ERR(st->dsa_gpios[0]),
+ "Failed to get gpios\n");
+
+ if (st->dsa_gpios[0]->ndescs != ADMF20000_DSA_GPIOS) {
+ dev_err_probe(dev, -ENODEV, "%d GPIOs needed to operate\n",
+ ADMF20000_DSA_GPIOS);
+ return -ENODEV;
+ }
+
+ st->dsa_gpios[1] = devm_gpiod_get_array(dev, "attenuation2",
+ GPIOD_OUT_LOW);
+ if (IS_ERR(st->dsa_gpios[1]))
+ return dev_err_probe(dev, PTR_ERR(st->dsa_gpios[1]),
+ "Failed to get gpios\n");
+
+ if (st->dsa_gpios[1]->ndescs != ADMF20000_DSA_GPIOS) {
+ dev_err_probe(dev, -ENODEV, "%d GPIOs needed to operate\n",
+ ADMF20000_DSA_GPIOS);
+ }
+
+ return 0;
+}
+
+static int admfm2000_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct iio_dev *indio_dev;
+ struct admfm2000_state *st;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ st = iio_priv(indio_dev);
+
+ indio_dev->name = "admfm2000";
+ indio_dev->num_channels = ARRAY_SIZE(admfm2000_channels);
+ indio_dev->channels = admfm2000_channels;
+ indio_dev->info = &admfm2000_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+
+ st->gain[0] = ADMF20000_DEFAULT_GAIN;
+ st->gain[1] = ADMF20000_DEFAULT_GAIN;
+
+ mutex_init(&st->lock);
+
+ ret = admfm2000_setup(st, indio_dev);
+ if (ret)
+ return ret;
+
+ ret = admfm2000_channel_config(st, indio_dev);
+ if (ret)
+ return ret;
+
+ return devm_iio_device_register(dev, indio_dev);
+}
+
+static const struct of_device_id admfm2000_of_match[] = {
+ { .compatible = "adi,admfm2000" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, admfm2000_of_match);
+
+static struct platform_driver admfm2000_driver = {
+ .driver = {
+ .name = "admfm2000",
+ .of_match_table = admfm2000_of_match,
+ },
+ .probe = admfm2000_probe,
+};
+module_platform_driver(admfm2000_driver);
+
+MODULE_AUTHOR("Kim Seer Paller <[email protected]>");
+MODULE_DESCRIPTION("ADMFM2000 Dual Microwave Down Converter");
+MODULE_LICENSE("GPL");
--
2.34.1

2023-11-22 18:22:47

by Krzysztof Kozlowski

[permalink] [raw]

Subject: Re: [PATCH v3 1/2] dt-bindings: iio: frequency: add admfm2000

On 22/11/2023 11:58, Kim Seer Paller wrote:
> Dual microwave down converter module with input RF and LO frequency
> ranges from 0.5 to 32 GHz and an output IF frequency range from 0.1 to
> 8 GHz. It consists of a LNA, mixer, IF filter, DSA, and IF amplifier
> for each down conversion path.
>
> Signed-off-by: Kim Seer Paller <[email protected]>
> Reported-by: kernel test robot <[email protected]>
> Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/

Drop these two tags. They are not valid.

> ---
> V2 -> V3: Adjusted indentation to resolve wrong indentation warning.
> Changed node name to converter. Updated the descriptions to clarify
> the properties.

> +title: ADMFM2000 Dual Microwave Down Converter
> +
> +maintainers:
> + - Kim Seer Paller <[email protected]>
> +
> +description:
> + Dual microwave down converter module with input RF and LO frequency ranges
> + from 0.5 to 32 GHz and an output IF frequency range from 0.1 to 8 GHz.
> + It consists of a LNA, mixer, IF filter, DSA, and IF amplifier for each down
> + conversion path.
> +
> +properties:
> + compatible:
> + enum:
> + - adi,admfm2000
> +
> + switch1-gpios:
> + items:
> + - description:
> + Setting B15 GPIO to high and B16 GPIO to low will result in channel 1
> + being in Direct IF mode.
> + - description:
> + Setting B15 GPIO to low and B16 GPIO to high will result in channel 1
> + being in Mixer mode.

This still does not tell which one is B15 and which is B16. I am asking
this for third time.

items:
- description: B15 GPIO, when high (and B16 low) channel 1 is in
Direct IF mode

Best regards,
Krzysztof

2023-11-23 06:14:30

by Paller, Kim Seer

[permalink] [raw]

Subject: RE: [PATCH v3 1/2] dt-bindings: iio: frequency: add admfm2000

> > ---
> > V2 -> V3: Adjusted indentation to resolve wrong indentation warning.
> > Changed node name to converter. Updated the descriptions to clarify
> > the properties.
>
>
> > +title: ADMFM2000 Dual Microwave Down Converter
> > +
> > +maintainers:
> > + - Kim Seer Paller <[email protected]>
> > +
> > +description:
> > + Dual microwave down converter module with input RF and LO frequency
> ranges
> > + from 0.5 to 32 GHz and an output IF frequency range from 0.1 to 8 GHz.
> > + It consists of a LNA, mixer, IF filter, DSA, and IF amplifier for each down
> > + conversion path.
> > +
> > +properties:
> > + compatible:
> > + enum:
> > + - adi,admfm2000
> > +
> > + switch1-gpios:
> > + items:
> > + - description:
> > + Setting B15 GPIO to high and B16 GPIO to low will result in channel 1
> > + being in Direct IF mode.
> > + - description:
> > + Setting B15 GPIO to low and B16 GPIO to high will result in channel 1
> > + being in Mixer mode.
>
> This still does not tell which one is B15 and which is B16. I am asking
> this for third time.
>
> items:
> - description: B15 GPIO, when high (and B16 low) channel 1 is in
> Direct IF mode

I understand now, thank you. I was also wondering if this applies to the
attenuation-gpios, or if I should keep it as is?

Best regards,
Kim

2023-11-23 07:21:04

by Krzysztof Kozlowski

[permalink] [raw]

Subject: Re: [PATCH v3 1/2] dt-bindings: iio: frequency: add admfm2000

On 23/11/2023 07:13, Paller, Kim Seer wrote:
>>> ---
>>> V2 -> V3: Adjusted indentation to resolve wrong indentation warning.
>>> Changed node name to converter. Updated the descriptions to clarify
>>> the properties.
>>
>>
>>> +title: ADMFM2000 Dual Microwave Down Converter
>>> +
>>> +maintainers:
>>> + - Kim Seer Paller <[email protected]>
>>> +
>>> +description:
>>> + Dual microwave down converter module with input RF and LO frequency
>> ranges
>>> + from 0.5 to 32 GHz and an output IF frequency range from 0.1 to 8 GHz.
>>> + It consists of a LNA, mixer, IF filter, DSA, and IF amplifier for each down
>>> + conversion path.
>>> +
>>> +properties:
>>> + compatible:
>>> + enum:
>>> + - adi,admfm2000
>>> +
>>> + switch1-gpios:
>>> + items:
>>> + - description:
>>> + Setting B15 GPIO to high and B16 GPIO to low will result in channel 1
>>> + being in Direct IF mode.
>>> + - description:
>>> + Setting B15 GPIO to low and B16 GPIO to high will result in channel 1
>>> + being in Mixer mode.
>>
>> This still does not tell which one is B15 and which is B16. I am asking
>> this for third time.
>>
>> items:
>> - description: B15 GPIO, when high (and B16 low) channel 1 is in
>> Direct IF mode
>
> I understand now, thank you. I was also wondering if this applies to the
> attenuation-gpios, or if I should keep it as is?

Yes, something like this applies to all your properties with multiple
entries. You need to define the order.

Best regards,
Krzysztof

2023-11-23 08:24:57

by Paller, Kim Seer

[permalink] [raw]

Subject: RE: [PATCH v3 1/2] dt-bindings: iio: frequency: add admfm2000

> >>> ---
> >>> V2 -> V3: Adjusted indentation to resolve wrong indentation warning.
> >>> Changed node name to converter. Updated the descriptions to clarify
> >>> the properties.
> >>
> >>
> >>> +title: ADMFM2000 Dual Microwave Down Converter
> >>> +
> >>> +maintainers:
> >>> + - Kim Seer Paller <[email protected]>
> >>> +
> >>> +description:
> >>> + Dual microwave down converter module with input RF and LO frequency
> >> ranges
> >>> + from 0.5 to 32 GHz and an output IF frequency range from 0.1 to 8 GHz.
> >>> + It consists of a LNA, mixer, IF filter, DSA, and IF amplifier for each down
> >>> + conversion path.
> >>> +
> >>> +properties:
> >>> + compatible:
> >>> + enum:
> >>> + - adi,admfm2000
> >>> +
> >>> + switch1-gpios:
> >>> + items:
> >>> + - description:
> >>> + Setting B15 GPIO to high and B16 GPIO to low will result in channel
> 1
> >>> + being in Direct IF mode.
> >>> + - description:
> >>> + Setting B15 GPIO to low and B16 GPIO to high will result in channel
> 1
> >>> + being in Mixer mode.
> >>
> >> This still does not tell which one is B15 and which is B16. I am asking
> >> this for third time.
> >>
> >> items:
> >> - description: B15 GPIO, when high (and B16 low) channel 1 is in
> >> Direct IF mode
> >
> > I understand now, thank you. I was also wondering if this applies to the
> > attenuation-gpios, or if I should keep it as is?
>
> Yes, something like this applies to all your properties with multiple
> entries. You need to define the order.

Before I send a new patch/commit, could you please check this one if it is
properly defined?

attenuation1-gpios:
items:
- description: C14 GPIO, when low (and C15, C16, D14, D15 high)
channel 1 attenuation is 1 dB.
- description: C15 GPIO, when low (and C14, C16, D14, D15 high)
channel 1 attenuation is 2 dB.
- description: C16 GPIO, when low (and C14, C15, D14, D15 high)
channel 1 attenuation is 4 dB.
- description: D14 GPIO, when low (and C14, C15, C16, D15 high)
channel 1 attenuation is 8 dB.
- description: D15 GPIO, when low (and C14, C15, C16, D14 high)
channel 1 attenuation is 16 dB.

Thanks,
Kim

2023-11-23 08:33:21

by Krzysztof Kozlowski

[permalink] [raw]

Subject: Re: [PATCH v3 1/2] dt-bindings: iio: frequency: add admfm2000

On 23/11/2023 09:24, Paller, Kim Seer wrote:
>>>>> ---
>>>>> V2 -> V3: Adjusted indentation to resolve wrong indentation warning.
>>>>> Changed node name to converter. Updated the descriptions to clarify
>>>>> the properties.
>>>>
>>>>
>>>>> +title: ADMFM2000 Dual Microwave Down Converter
>>>>> +
>>>>> +maintainers:
>>>>> + - Kim Seer Paller <[email protected]>
>>>>> +
>>>>> +description:
>>>>> + Dual microwave down converter module with input RF and LO frequency
>>>> ranges
>>>>> + from 0.5 to 32 GHz and an output IF frequency range from 0.1 to 8 GHz.
>>>>> + It consists of a LNA, mixer, IF filter, DSA, and IF amplifier for each down
>>>>> + conversion path.
>>>>> +
>>>>> +properties:
>>>>> + compatible:
>>>>> + enum:
>>>>> + - adi,admfm2000
>>>>> +
>>>>> + switch1-gpios:
>>>>> + items:
>>>>> + - description:
>>>>> + Setting B15 GPIO to high and B16 GPIO to low will result in channel
>> 1
>>>>> + being in Direct IF mode.
>>>>> + - description:
>>>>> + Setting B15 GPIO to low and B16 GPIO to high will result in channel
>> 1
>>>>> + being in Mixer mode.
>>>>
>>>> This still does not tell which one is B15 and which is B16. I am asking
>>>> this for third time.
>>>>
>>>> items:
>>>> - description: B15 GPIO, when high (and B16 low) channel 1 is in
>>>> Direct IF mode
>>>
>>> I understand now, thank you. I was also wondering if this applies to the
>>> attenuation-gpios, or if I should keep it as is?
>>
>> Yes, something like this applies to all your properties with multiple
>> entries. You need to define the order.
>
> Before I send a new patch/commit, could you please check this one if it is
> properly defined?
>
> attenuation1-gpios:
> items:
> - description: C14 GPIO, when low (and C15, C16, D14, D15 high)
> channel 1 attenuation is 1 dB.
> - description: C15 GPIO, when low (and C14, C16, D14, D15 high)
> channel 1 attenuation is 2 dB.
> - description: C16 GPIO, when low (and C14, C15, D14, D15 high)
> channel 1 attenuation is 4 dB.
> - description: D14 GPIO, when low (and C14, C15, C16, D15 high)
> channel 1 attenuation is 8 dB.
> - description: D15 GPIO, when low (and C14, C15, C16, D14 high)
> channel 1 attenuation is 16 dB.

This actually could be written in easier way like:

attenuation1-gpios:
description: |
Choice of attenuation:
C14 C15 ......
1 0 0 0 - 1 dB
0 1 0 0 - 2 dB
...
items:
- description: C14 GPIO
- description: C15 GPIO
- description: C16 GPIO
- description: D14 GPIO
- description: D15 GPIO

or whatever is easy to understand. The point is that you must define the
order of GPIOs and explain their meaning.

Best regards,
Krzysztof