[PATCH v5 1/5] iio: core: Handle 'dB' suffix in core

[PATCH v5 1/5] iio: core: Handle 'dB' suffix in core

[Beniamin Bia]

This patch handles the db suffix used for writing micro db values.

Signed-off-by: Beniamin Bia <beniamin.bia@analog.com>
---
Changes in v5:
-handle both 'db' and ' db' cases

 drivers/iio/industrialio-core.c | 39 ++++++++++++++++++++++++++++++---
 1 file changed, 36 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index 65ff0d067018..684c3b151b29 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -769,17 +769,18 @@ static ssize_t iio_read_channel_info_avail(struct device *dev,
 }
 
 /**
- * iio_str_to_fixpoint() - Parse a fixed-point number from a string
+ * __iio_str_to_fixpoint() - Parse a fixed-point number from a string
  * @str: The string to parse
  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
  * @integer: The integer part of the number
  * @fract: The fractional part of the number
+ * @scale_db: True if this should parse as dB
  *
  * Returns 0 on success, or a negative error code if the string could not be
  * parsed.
  */
-int iio_str_to_fixpoint(const char *str, int fract_mult,
-	int *integer, int *fract)
+int __iio_str_to_fixpoint(const char *str, int fract_mult,
+			  int *integer, int *fract, bool scale_db)
 {
 	int i = 0, f = 0;
 	bool integer_part = true, negative = false;
@@ -810,6 +811,14 @@ int iio_str_to_fixpoint(const char *str, int fract_mult,
 				break;
 			else
 				return -EINVAL;
+		} else if (!strncmp(str, " dB", sizeof(" dB") - 1) && scale_db) {
+			/* Ignore the dB suffix */
+			str += sizeof(" dB") - 1;
+			continue;
+		} else if (!strncmp(str, "dB", sizeof("dB") - 1) && scale_db) {
+			/* Ignore the dB suffix */
+			str += sizeof("dB") - 1;
+			continue;
 		} else if (*str == '.' && integer_part) {
 			integer_part = false;
 		} else {
@@ -832,6 +841,22 @@ int iio_str_to_fixpoint(const char *str, int fract_mult,
 }
 EXPORT_SYMBOL_GPL(iio_str_to_fixpoint);
 
+/**
+ * iio_str_to_fixpoint() - Parse a fixed-point number from a string
+ * @str: The string to parse
+ * @fract_mult: Multiplier for the first decimal place, should be a power of 10
+ * @integer: The integer part of the number
+ * @fract: The fractional part of the number
+ *
+ * Returns 0 on success, or a negative error code if the string could not be
+ * parsed.
+ */
+int iio_str_to_fixpoint(const char *str, int fract_mult,
+			int *integer, int *fract)
+{
+	return __iio_str_to_fixpoint(str, fract_mult, integer, fract, false);
+}
+
 static ssize_t iio_write_channel_info(struct device *dev,
 				      struct device_attribute *attr,
 				      const char *buf,
@@ -842,6 +867,7 @@ static ssize_t iio_write_channel_info(struct device *dev,
 	int ret, fract_mult = 100000;
 	int integer, fract = 0;
 	bool is_char = false;
+	bool scale_db = false;
 
 	/* Assumes decimal - precision based on number of digits */
 	if (!indio_dev->info->write_raw)
@@ -853,6 +879,9 @@ static ssize_t iio_write_channel_info(struct device *dev,
 		case IIO_VAL_INT:
 			fract_mult = 0;
 			break;
+		case IIO_VAL_INT_PLUS_MICRO_DB:
+			scale_db = true;
+			/* fall through */
 		case IIO_VAL_INT_PLUS_MICRO:
 			fract_mult = 100000;
 			break;
@@ -877,6 +906,10 @@ static ssize_t iio_write_channel_info(struct device *dev,
 		if (ret)
 			return ret;
 	}
+	ret = __iio_str_to_fixpoint(buf, fract_mult, &integer, &fract,
+				    scale_db);
+	if (ret)
+		return ret;
 
 	ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
 					 integer, fract, this_attr->address);
-- 
2.17.1

[PATCH v5 2/5] iio: amplifiers: ad8366: Add write_raw_get_fmt function

[Beniamin Bia]

This patch add write_raw_get_fmt function to specify conversion for
hardware gain.

Signed-off-by: Beniamin Bia <beniamin.bia@analog.com>
---
Changes in v5:
-nothing changed

 drivers/iio/amplifiers/ad8366.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/iio/amplifiers/ad8366.c b/drivers/iio/amplifiers/ad8366.c
index 0176d3d8cc9c..95972ab60f42 100644
--- a/drivers/iio/amplifiers/ad8366.c
+++ b/drivers/iio/amplifiers/ad8366.c
@@ -180,9 +180,22 @@ static int ad8366_write_raw(struct iio_dev *indio_dev,
 	return ret;
 }
 
+static int ad8366_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 ad8366_info = {
 	.read_raw = &ad8366_read_raw,
 	.write_raw = &ad8366_write_raw,
+	.write_raw_get_fmt = &ad8366_write_raw_get_fmt,
 };
 
 #define AD8366_CHAN(_channel) {				\
-- 
2.17.1

Re: [PATCH v5 2/5] iio: amplifiers: ad8366: Add write_raw_get_fmt function

[Jonathan Cameron]

On Thu, 6 Feb 2020 17:11:46 +0200
Beniamin Bia <beniamin.bia@analog.com> wrote:

> This patch add write_raw_get_fmt function to specify conversion for
> hardware gain.
> 
> Signed-off-by: Beniamin Bia <beniamin.bia@analog.com>
Applied to the togreg branch of iio.git and pushed out as testing for
the autobuilders to play with it.

Thanks,

Jonathan

> ---
> Changes in v5:
> -nothing changed
> 
>  drivers/iio/amplifiers/ad8366.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/drivers/iio/amplifiers/ad8366.c b/drivers/iio/amplifiers/ad8366.c
> index 0176d3d8cc9c..95972ab60f42 100644
> --- a/drivers/iio/amplifiers/ad8366.c
> +++ b/drivers/iio/amplifiers/ad8366.c
> @@ -180,9 +180,22 @@ static int ad8366_write_raw(struct iio_dev *indio_dev,
>  	return ret;
>  }
>  
> +static int ad8366_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 ad8366_info = {
>  	.read_raw = &ad8366_read_raw,
>  	.write_raw = &ad8366_write_raw,
> +	.write_raw_get_fmt = &ad8366_write_raw_get_fmt,
>  };
>  
>  #define AD8366_CHAN(_channel) {				\

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

[Beniamin Bia]

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>
---
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
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");
+	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");
-- 
2.17.1

Re: [PATCH v5 3/5] iio: amplifiers: hmc425a: Add support for HMC425A attenuator

[Jonathan Cameron]

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");

Re: [PATCH v5 3/5] iio: amplifiers: hmc425a: Add support for HMC425A attenuator

[Bia, Beniamin]

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");
> 
> 

Re: [PATCH v5 3/5] iio: amplifiers: hmc425a: Add support for HMC425A attenuator

[Jonathan Cameron]

Hi Ben, 

Just noticed, the author for this doesn't match the module author
or the first sign off.
I've fixed up.  Hope that's fine with you and Michael.

Jonathan


On Thu, 20 Feb 2020 12:32:35 +0000
"Bia, Beniamin" <Beniamin.Bia@analog.com> wrote:

> 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");  
> > 
> >   

[PATCH v5 4/5] dt-bindings: iio: amplifiers: Add docs for HMC425A Step Attenuator

[Beniamin Bia]

From: Michael Hennerich <michael.hennerich@analog.com>

Document support for Analog Devices MC425A Step Attenuator.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Beniamin Bia <beniamin.bia@analog.com>
---
Changes in v5:
-minItems added for ctrl_gpios

 .../bindings/iio/amplifiers/adi,hmc425a.yaml  | 49 +++++++++++++++++++
 1 file changed, 49 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/amplifiers/adi,hmc425a.yaml

diff --git a/Documentation/devicetree/bindings/iio/amplifiers/adi,hmc425a.yaml b/Documentation/devicetree/bindings/iio/amplifiers/adi,hmc425a.yaml
new file mode 100644
index 000000000000..1c6d49685e9f
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/amplifiers/adi,hmc425a.yaml
@@ -0,0 +1,49 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/amplifiers/adi,hmc425a.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: HMC425A 6-bit Digital Step Attenuator
+
+maintainers:
+- Michael Hennerich <michael.hennerich@analog.com>
+- Beniamin Bia <beniamin.bia@analog.com>
+
+description: |
+  Digital Step Attenuator IIO device with gpio interface.
+  HMC425A 0.5 dB LSB GaAs MMIC 6-BIT DIGITAL POSITIVE CONTROL ATTENUATOR, 2.2 - 8.0 GHz
+  https://www.analog.com/media/en/technical-documentation/data-sheets/hmc425A.pdf
+
+properties:
+  compatible:
+    enum:
+      - adi,hmc425a
+
+  vcc-supply: true
+
+  ctrl-gpios:
+    description:
+      Must contain an array of 6 GPIO specifiers, referring to the GPIO pins
+      connected to the control pins V1-V6.
+    minItems: 6
+    maxItems: 6
+
+required:
+  - compatible
+  - ctrl-gpios
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    gpio_hmc425a: hmc425a {
+      compatible = "adi,hmc425a";
+      ctrl-gpios = <&gpio 40 GPIO_ACTIVE_HIGH>,
+        <&gpio 39 GPIO_ACTIVE_HIGH>,
+        <&gpio 38 GPIO_ACTIVE_HIGH>,
+        <&gpio 37 GPIO_ACTIVE_HIGH>,
+        <&gpio 36 GPIO_ACTIVE_HIGH>,
+        <&gpio 35 GPIO_ACTIVE_HIGH>;
+      vcc-supply = <&foo>;
+    };
+...
-- 
2.17.1

Re: [PATCH v5 4/5] dt-bindings: iio: amplifiers: Add docs for HMC425A Step Attenuator

[Rob Herring]

On Thu, Feb 06, 2020 at 05:11:48PM +0200, Beniamin Bia wrote:
> From: Michael Hennerich <michael.hennerich@analog.com>
> 
> Document support for Analog Devices MC425A Step Attenuator.
> 
> Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
> Signed-off-by: Beniamin Bia <beniamin.bia@analog.com>
> ---
> Changes in v5:
> -minItems added for ctrl_gpios
> 
>  .../bindings/iio/amplifiers/adi,hmc425a.yaml  | 49 +++++++++++++++++++
>  1 file changed, 49 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/amplifiers/adi,hmc425a.yaml

Reviewed-by: Rob Herring <robh@kernel.org>

Re: [PATCH v5 4/5] dt-bindings: iio: amplifiers: Add docs for HMC425A Step Attenuator

[Jonathan Cameron]

On Thu, 6 Feb 2020 14:34:27 -0700
Rob Herring <robh@kernel.org> wrote:

> On Thu, Feb 06, 2020 at 05:11:48PM +0200, Beniamin Bia wrote:
> > From: Michael Hennerich <michael.hennerich@analog.com>
> > 
> > Document support for Analog Devices MC425A Step Attenuator.
> > 
> > Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
> > Signed-off-by: Beniamin Bia <beniamin.bia@analog.com>
> > ---
> > Changes in v5:
> > -minItems added for ctrl_gpios
> > 
> >  .../bindings/iio/amplifiers/adi,hmc425a.yaml  | 49 +++++++++++++++++++
> >  1 file changed, 49 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/iio/amplifiers/adi,hmc425a.yaml  
> 
> Reviewed-by: Rob Herring <robh@kernel.org>

Applied.  Thanks,

Jonathan

[PATCH v5 5/5] MAINTAINERS: add entry for hmc425a driver.

[Beniamin Bia]

Add Beniamin Bia and Michael Hennerich as maintainers for HMC425A
attenuator.

Signed-off-by: Beniamin Bia <beniamin.bia@analog.com>
---
Changes in v5:
-parse_maintainers runned

 MAINTAINERS | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index e699fe378e71..12e39dc0dc93 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1063,6 +1063,15 @@ F:	drivers/iio/adc/ltc249*
 X:	drivers/iio/*/adjd*
 F:	drivers/staging/iio/*/ad*
 
+ANALOG DEVICES INC HMC425A DRIVER
+M:	Beniamin Bia <beniamin.bia@analog.com>
+M:	Michael Hennerich <michael.hennerich@analog.com>
+L:	linux-iio@vger.kernel.org
+S:	Supported
+W:	http://ez.analog.com/community/linux-device-drivers
+F:	Documentation/devicetree/bindings/iio/amplifiers/adi,hmc425a.yaml
+F:	drivers/iio/amplifiers/hmc425a.c
+
 ANALOGBITS PLL LIBRARIES
 M:	Paul Walmsley <paul.walmsley@sifive.com>
 S:	Supported
-- 
2.17.1

Re: [PATCH v5 5/5] MAINTAINERS: add entry for hmc425a driver.

[Jonathan Cameron]

On Thu, 6 Feb 2020 17:11:49 +0200
Beniamin Bia <beniamin.bia@analog.com> wrote:

> Add Beniamin Bia and Michael Hennerich as maintainers for HMC425A
> attenuator.
> 
> Signed-off-by: Beniamin Bia <beniamin.bia@analog.com>
Applied.

Thanks,

Jonathan

> ---
> Changes in v5:
> -parse_maintainers runned
> 
>  MAINTAINERS | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index e699fe378e71..12e39dc0dc93 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -1063,6 +1063,15 @@ F:	drivers/iio/adc/ltc249*
>  X:	drivers/iio/*/adjd*
>  F:	drivers/staging/iio/*/ad*
>  
> +ANALOG DEVICES INC HMC425A DRIVER
> +M:	Beniamin Bia <beniamin.bia@analog.com>
> +M:	Michael Hennerich <michael.hennerich@analog.com>
> +L:	linux-iio@vger.kernel.org
> +S:	Supported
> +W:	http://ez.analog.com/community/linux-device-drivers
> +F:	Documentation/devicetree/bindings/iio/amplifiers/adi,hmc425a.yaml
> +F:	drivers/iio/amplifiers/hmc425a.c
> +
>  ANALOGBITS PLL LIBRARIES
>  M:	Paul Walmsley <paul.walmsley@sifive.com>
>  S:	Supported

Re: [PATCH v5 1/5] iio: core: Handle 'dB' suffix in core

[Jonathan Cameron]

On Thu, 6 Feb 2020 17:11:45 +0200
Beniamin Bia <beniamin.bia@analog.com> wrote:

> This patch handles the db suffix used for writing micro db values.
> 
> Signed-off-by: Beniamin Bia <beniamin.bia@analog.com>
A few things came up in build tests that I've fixed up. See inline.

Applied to the togreg branch of iio.git and pushed out as testing for
the autobuilders to play with it.
Thanks,

Jonathan

> ---
> Changes in v5:
> -handle both 'db' and ' db' cases
> 
>  drivers/iio/industrialio-core.c | 39 ++++++++++++++++++++++++++++++---
>  1 file changed, 36 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
> index 65ff0d067018..684c3b151b29 100644
> --- a/drivers/iio/industrialio-core.c
> +++ b/drivers/iio/industrialio-core.c
> @@ -769,17 +769,18 @@ static ssize_t iio_read_channel_info_avail(struct device *dev,
>  }
>  
>  /**
> - * iio_str_to_fixpoint() - Parse a fixed-point number from a string
> + * __iio_str_to_fixpoint() - Parse a fixed-point number from a string
>   * @str: The string to parse
>   * @fract_mult: Multiplier for the first decimal place, should be a power of 10
>   * @integer: The integer part of the number
>   * @fract: The fractional part of the number
> + * @scale_db: True if this should parse as dB
>   *
>   * Returns 0 on success, or a negative error code if the string could not be
>   * parsed.
>   */
> -int iio_str_to_fixpoint(const char *str, int fract_mult,
> -	int *integer, int *fract)
> +int __iio_str_to_fixpoint(const char *str, int fract_mult,
> +			  int *integer, int *fract, bool scale_db)
Should be static.

>  {
>  	int i = 0, f = 0;
>  	bool integer_part = true, negative = false;
> @@ -810,6 +811,14 @@ int iio_str_to_fixpoint(const char *str, int fract_mult,
>  				break;
>  			else
>  				return -EINVAL;
> +		} else if (!strncmp(str, " dB", sizeof(" dB") - 1) && scale_db) {
> +			/* Ignore the dB suffix */
> +			str += sizeof(" dB") - 1;
> +			continue;
> +		} else if (!strncmp(str, "dB", sizeof("dB") - 1) && scale_db) {
> +			/* Ignore the dB suffix */
> +			str += sizeof("dB") - 1;
> +			continue;
>  		} else if (*str == '.' && integer_part) {
>  			integer_part = false;
>  		} else {
> @@ -832,6 +841,22 @@ int iio_str_to_fixpoint(const char *str, int fract_mult,
>  }
>  EXPORT_SYMBOL_GPL(iio_str_to_fixpoint);
>  
> +/**
> + * iio_str_to_fixpoint() - Parse a fixed-point number from a string
> + * @str: The string to parse
> + * @fract_mult: Multiplier for the first decimal place, should be a power of 10
> + * @integer: The integer part of the number
> + * @fract: The fractional part of the number
> + *
> + * Returns 0 on success, or a negative error code if the string could not be
> + * parsed.
> + */
> +int iio_str_to_fixpoint(const char *str, int fract_mult,
> +			int *integer, int *fract)
> +{
> +	return __iio_str_to_fixpoint(str, fract_mult, integer, fract, false);
> +}
The export symbol should have moved to here to follow the function.
> +
>  static ssize_t iio_write_channel_info(struct device *dev,
>  				      struct device_attribute *attr,
>  				      const char *buf,
> @@ -842,6 +867,7 @@ static ssize_t iio_write_channel_info(struct device *dev,
>  	int ret, fract_mult = 100000;
>  	int integer, fract = 0;
>  	bool is_char = false;
> +	bool scale_db = false;
>  
>  	/* Assumes decimal - precision based on number of digits */
>  	if (!indio_dev->info->write_raw)
> @@ -853,6 +879,9 @@ static ssize_t iio_write_channel_info(struct device *dev,
>  		case IIO_VAL_INT:
>  			fract_mult = 0;
>  			break;
> +		case IIO_VAL_INT_PLUS_MICRO_DB:
> +			scale_db = true;
> +			/* fall through */
>  		case IIO_VAL_INT_PLUS_MICRO:
>  			fract_mult = 100000;
>  			break;
> @@ -877,6 +906,10 @@ static ssize_t iio_write_channel_info(struct device *dev,
>  		if (ret)
>  			return ret;
>  	}
> +	ret = __iio_str_to_fixpoint(buf, fract_mult, &integer, &fract,
> +				    scale_db);
> +	if (ret)
> +		return ret;
>  
>  	ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
>  					 integer, fract, this_attr->address);