Changes in v4:
-handle db patch was added
-gpiod_set_array_value_cansleep call was updated
Beniamin Bia (4):
iio: core: Handle 'dB' suffix in core
iio: amplifiers: ad8366: Add write_raw_get_fmt function
iio: amplifiers: hmc425a: Add support for HMC425A attenuator
MAINTAINERS: add entry for hmc425a driver.
Michael Hennerich (1):
dt-bindings: iio: amplifiers: Add docs for HMC425A Step Attenuator
.../bindings/iio/amplifiers/adi,hmc425a.yaml | 48 ++++
MAINTAINERS | 9 +
drivers/iio/amplifiers/Kconfig | 10 +
drivers/iio/amplifiers/Makefile | 1 +
drivers/iio/amplifiers/ad8366.c | 13 +
drivers/iio/amplifiers/hmc425a.c | 256 ++++++++++++++++++
drivers/iio/industrialio-core.c | 35 ++-
7 files changed, 369 insertions(+), 3 deletions(-)
create mode 100644 Documentation/devicetree/bindings/iio/amplifiers/adi,hmc425a.yaml
create mode 100644 drivers/iio/amplifiers/hmc425a.c
--
2.17.1
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 <[email protected]>
Signed-off-by: Alexandru Ardelean <[email protected]>
Signed-off-by: Beniamin Bia <[email protected]>
---
drivers/iio/amplifiers/Kconfig | 10 ++
drivers/iio/amplifiers/Makefile | 1 +
drivers/iio/amplifiers/hmc425a.c | 256 +++++++++++++++++++++++++++++++
3 files changed, 267 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..0a797e56df3d
--- /dev/null
+++ b/drivers/iio/amplifiers/hmc425a.c
@@ -0,0 +1,256 @@
+// 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)
+{
+ const struct of_device_id *id;
+ 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);
+ id = of_match_device(hmc425a_of_match, &pdev->dev);
+ if (!id)
+ ret = -ENODEV;
+
+ st->type = (enum hmc425a_type)id->data;
+
+ 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 <[email protected]>");
+MODULE_DESCRIPTION("Analog Devices HMC425A and similar GPIO control Gain Amplifiers");
+MODULE_LICENSE("GPL v2");
--
2.17.1
Add Beniamin Bia and Michael Hennerich as maintainers for HMC425A
attenuator.
Signed-off-by: Beniamin Bia <[email protected]>
---
MAINTAINERS | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index e699fe378e71..06c283553e30 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 <[email protected]>
+M: Michael Hennerich <[email protected]>
+L: [email protected]
+W: http://ez.analog.com/community/linux-device-drivers
+S: Supported
+F: drivers/iio/amplifiers/hmc425a.c
+F: Documentation/devicetree/bindings/iio/amplifiers/adi,hmc425a.yaml
+
ANALOGBITS PLL LIBRARIES
M: Paul Walmsley <[email protected]>
S: Supported
--
2.17.1
This patch add write_raw_get_fmt function to specify conversion for
hardware gain.
Signed-off-by: Beniamin Bia <[email protected]>
---
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
This patch handles the db suffix used for writing micro db values.
Signed-off-by: Beniamin Bia <[email protected]>
---
drivers/iio/industrialio-core.c | 35 ++++++++++++++++++++++++++++++---
1 file changed, 32 insertions(+), 3 deletions(-)
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index 65ff0d067018..b70111837420 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 +811,10 @@ 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 (*str == '.' && integer_part) {
integer_part = false;
} else {
@@ -832,6 +837,22 @@ 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 +863,7 @@ 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 +875,9 @@ 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 +902,10 @@ 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
From: Michael Hennerich <[email protected]>
Document support for Analog Devices MC425A Step Attenuator.
Signed-off-by: Michael Hennerich <[email protected]>
Signed-off-by: Beniamin Bia <[email protected]>
---
.../bindings/iio/amplifiers/adi,hmc425a.yaml | 48 +++++++++++++++++++
1 file changed, 48 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..d800639c14a5
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/amplifiers/adi,hmc425a.yaml
@@ -0,0 +1,48 @@
+# 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 <[email protected]>
+- Beniamin Bia <[email protected]>
+
+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.
+ 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
On Wed, 29 Jan 2020 16:22:57 +0200
Beniamin Bia <[email protected]> wrote:
> This patch handles the db suffix used for writing micro db values.
>
> Signed-off-by: Beniamin Bia <[email protected]>
> ---
> drivers/iio/industrialio-core.c | 35 ++++++++++++++++++++++++++++++---
> 1 file changed, 32 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
> index 65ff0d067018..b70111837420 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 +811,10 @@ 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) {
I think we need to ignore spacing between the value and the dB.
We could do that by ignoring spaces in general, but that will lead
to odd results in other cases. Perhaps we just need to handle " dB" and "dB"
to cover likely options?
> + /* Ignore the dB suffix */
> + str += sizeof(" dB") - 1;
> + continue;
> } else if (*str == '.' && integer_part) {
> integer_part = false;
> } else {
> @@ -832,6 +837,22 @@ 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 +863,7 @@ 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 +875,9 @@ 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 +902,10 @@ 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);
On Wed, 29 Jan 2020 16:22:59 +0200
Beniamin Bia <[email protected]> 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 <[email protected]>
> Signed-off-by: Alexandru Ardelean <[email protected]>
> Signed-off-by: Beniamin Bia <[email protected]>
A few really small things I noticed whilst taking another quick look at this.
I'd probably just have tidied them up or let the go if I hadn't already
raised feedback on patch 1 :)
Thanks,
Jonathan
> ---
> drivers/iio/amplifiers/Kconfig | 10 ++
> drivers/iio/amplifiers/Makefile | 1 +
> drivers/iio/amplifiers/hmc425a.c | 256 +++++++++++++++++++++++++++++++
> 3 files changed, 267 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..0a797e56df3d
> --- /dev/null
> +++ b/drivers/iio/amplifiers/hmc425a.c
> @@ -0,0 +1,256 @@
> +// 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, \
I'd rather see these on separate lines.
Not sure there are hard rules in the kernel for this particular case
but there are for normal initializers to say you shouldn't do
int a = 1, b = 2, c = 1; etc and this is kind of similar.
> + .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)
> +{
> + const struct of_device_id *id;
> + 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);
> + id = of_match_device(hmc425a_of_match, &pdev->dev);
> + if (!id)
> + ret = -ENODEV;
> +
> + st->type = (enum hmc425a_type)id->data;
of_device_get_match_data instead of of_match_device as we never
actually want the of_device_id itself.
> +
> + 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 <[email protected]>");
> +MODULE_DESCRIPTION("Analog Devices HMC425A and similar GPIO control Gain Amplifiers");
> +MODULE_LICENSE("GPL v2");
On Wed, 29 Jan 2020 16:23:00 +0200
Beniamin Bia <[email protected]> wrote:
> From: Michael Hennerich <[email protected]>
>
> Document support for Analog Devices MC425A Step Attenuator.
>
> Signed-off-by: Michael Hennerich <[email protected]>
> Signed-off-by: Beniamin Bia <[email protected]>
> ---
> .../bindings/iio/amplifiers/adi,hmc425a.yaml | 48 +++++++++++++++++++
> 1 file changed, 48 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..d800639c14a5
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/amplifiers/adi,hmc425a.yaml
> @@ -0,0 +1,48 @@
> +# 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 <[email protected]>
> +- Beniamin Bia <[email protected]>
> +
> +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.
> + maxItems: 6
Does this force exactly 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>;
> + };
> +...
On Wed, Jan 29, 2020 at 4:24 PM Beniamin Bia <[email protected]> wrote:
>
> Add Beniamin Bia and Michael Hennerich as maintainers for HMC425A
> attenuator.
> +ANALOG DEVICES INC HMC425A DRIVER
> +M: Beniamin Bia <[email protected]>
> +M: Michael Hennerich <[email protected]>
> +L: [email protected]
> +W: http://ez.analog.com/community/linux-device-drivers
> +S: Supported
> +F: drivers/iio/amplifiers/hmc425a.c
> +F: Documentation/devicetree/bindings/iio/amplifiers/adi,hmc425a.yaml
Had you run parse-maintainers.pl afterwards to see if everything is okay?
--
With Best Regards,
Andy Shevchenko
On Sun, 2020-02-02 at 10:53 +0000, Jonathan Cameron wrote:
> On Wed, 29 Jan 2020 16:23:00 +0200
> Beniamin Bia <[email protected]> wrote:
>
> > From: Michael Hennerich <[email protected]>
> >
> > Document support for Analog Devices MC425A Step Attenuator.
> >
> > Signed-off-by: Michael Hennerich <[email protected]>
> > Signed-off-by: Beniamin Bia <[email protected]>
> > ---
> > .../bindings/iio/amplifiers/adi,hmc425a.yaml | 48 +++++++++++++++++++
> > 1 file changed, 48 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..d800639c14a5
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/iio/amplifiers/adi,hmc425a.yaml
> > @@ -0,0 +1,48 @@
> > +# 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 <[email protected]>
> > +- Beniamin Bia <[email protected]>
> > +
> > +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.
> > + maxItems: 6
>
> Does this force exactly 6?
I'm [also] a bit unsure whether to force this number in DT.
One idea [with this driver] would be to maybe have it support multiple of these
GPIO-controlled attenuators/amplifiers. And those could have a higher/lower
number of GPIOs.
In any case, we could enforce this as-is [for now], and see later when/if adding
new parts.
No strong opinion from my side about this though.
>
> > +
> > +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>;
> > + };
> > +...
On Mon, 3 Feb 2020 11:25:48 +0000
"Ardelean, Alexandru" <[email protected]> wrote:
> On Sun, 2020-02-02 at 10:53 +0000, Jonathan Cameron wrote:
> > On Wed, 29 Jan 2020 16:23:00 +0200
> > Beniamin Bia <[email protected]> wrote:
> >
> > > From: Michael Hennerich <[email protected]>
> > >
> > > Document support for Analog Devices MC425A Step Attenuator.
> > >
> > > Signed-off-by: Michael Hennerich <[email protected]>
> > > Signed-off-by: Beniamin Bia <[email protected]>
> > > ---
> > > .../bindings/iio/amplifiers/adi,hmc425a.yaml | 48 +++++++++++++++++++
> > > 1 file changed, 48 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..d800639c14a5
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/iio/amplifiers/adi,hmc425a.yaml
> > > @@ -0,0 +1,48 @@
> > > +# 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 <[email protected]>
> > > +- Beniamin Bia <[email protected]>
> > > +
> > > +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.
> > > + maxItems: 6
> >
> > Does this force exactly 6?
>
> I'm [also] a bit unsure whether to force this number in DT.
> One idea [with this driver] would be to maybe have it support multiple of these
> GPIO-controlled attenuators/amplifiers. And those could have a higher/lower
> number of GPIOs.
>
> In any case, we could enforce this as-is [for now], and see later when/if adding
> new parts.
> No strong opinion from my side about this though.
It should be enforced for each of the devices supported.
So for devices with less, it would only allow precisely that
lesser number.
One slight quirk is someone crazy might wire certain pins to high or low
because they don't need the precision.
Not sure how we handle that one but can deal with it when it happens.
Jonathan
>
> >
> > > +
> > > +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>;
> > > + };
> > > +...
On Wed, 29 Jan 2020 16:23:00 +0200, Beniamin Bia wrote:
> From: Michael Hennerich <[email protected]>
>
> Document support for Analog Devices MC425A Step Attenuator.
>
> Signed-off-by: Michael Hennerich <[email protected]>
> Signed-off-by: Beniamin Bia <[email protected]>
> ---
> .../bindings/iio/amplifiers/adi,hmc425a.yaml | 48 +++++++++++++++++++
> 1 file changed, 48 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/iio/amplifiers/adi,hmc425a.yaml
>
Reviewed-by: Rob Herring <[email protected]>