The AD5110/AD5112/AD5114 provide a nonvolatile solution
for 128-/64-/32-position adjustment applications, offering
guaranteed low resistor tolerance errors of ±8% and up to
±6 mA current density.
Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/AD5110_5112_5114.pdf
Signed-off-by: Mugilraj Dhavachelvan <[email protected]>
---
MAINTAINERS | 6 +
drivers/iio/potentiometer/Kconfig | 10 +
drivers/iio/potentiometer/Makefile | 1 +
drivers/iio/potentiometer/ad5110.c | 339 +++++++++++++++++++++++++++++
4 files changed, 356 insertions(+)
create mode 100644 drivers/iio/potentiometer/ad5110.c
diff --git a/MAINTAINERS b/MAINTAINERS
index bd7aff0c120f..cf6e73b87b6e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -452,6 +452,12 @@ S: Maintained
W: https://parisc.wiki.kernel.org/index.php/AD1889
F: sound/pci/ad1889.*
+AD5110 ANALOG DEVICES DIGITAL POTENTIOMETERS DRIVER
+M: Mugilraj Dhavachelvan <[email protected]>
+L: [email protected]
+S: Supported
+F: drivers/iio/potentiometer/ad5110.c
+
AD525X ANALOG DEVICES DIGITAL POTENTIOMETERS DRIVER
M: Michael Hennerich <[email protected]>
S: Supported
diff --git a/drivers/iio/potentiometer/Kconfig b/drivers/iio/potentiometer/Kconfig
index 4cac0173db8b..832df8da2bc6 100644
--- a/drivers/iio/potentiometer/Kconfig
+++ b/drivers/iio/potentiometer/Kconfig
@@ -6,6 +6,16 @@
menu "Digital potentiometers"
+config AD5110
+ tristate "Analog Devices AD5110 and similar Digital Potentiometer driver"
+ depends on I2C
+ help
+ Say yes here to build support for the Analog Devices AD5110, AD5112
+ and AD5114 digital potentiometer chip.
+
+ To compile this driver as a module, choose M here: the
+ module will be called ad5110.
+
config AD5272
tristate "Analog Devices AD5272 and similar Digital Potentiometer driver"
depends on I2C
diff --git a/drivers/iio/potentiometer/Makefile b/drivers/iio/potentiometer/Makefile
index 091adf3cdd0b..5ebb8e3bbd76 100644
--- a/drivers/iio/potentiometer/Makefile
+++ b/drivers/iio/potentiometer/Makefile
@@ -4,6 +4,7 @@
#
# When adding new entries keep the list in alphabetical order
+obj-$(CONFIG_AD5110) += ad5110.o
obj-$(CONFIG_AD5272) += ad5272.o
obj-$(CONFIG_DS1803) += ds1803.o
obj-$(CONFIG_MAX5432) += max5432.o
diff --git a/drivers/iio/potentiometer/ad5110.c b/drivers/iio/potentiometer/ad5110.c
new file mode 100644
index 000000000000..4ba76e968edb
--- /dev/null
+++ b/drivers/iio/potentiometer/ad5110.c
@@ -0,0 +1,339 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Analog Devices AD5110 digital potentiometer driver
+ *
+ * Copyright (C) 2021 Mugilraj Dhavachelvan <[email protected]>
+ *
+ * Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/AD5110_5112_5114.pdf
+ *
+ */
+
+#include <linux/bitfield.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+/* AD5110 commands */
+#define AD5110_EEPROM_WR 1
+#define AD5110_RDAC_WR 2
+#define AD5110_SHUTDOWN 3
+#define AD5110_RESET 4
+#define AD5110_RDAC_RD 5
+#define AD5110_EEPROM_RD 6
+
+/* AD5110_EEPROM_RD data */
+#define AD5110_WIPER_POS 0
+#define AD5110_RESISTOR_TOL 1
+
+#define WIPER_RESISTANCE 70
+
+struct ad5110_cfg {
+ int max_pos;
+ int kohms;
+ int shift;
+};
+
+enum ad5110_type {
+ AD5110_10,
+ AD5110_80,
+ AD5112_05,
+ AD5112_10,
+ AD5112_80,
+ AD5114_10,
+ AD5114_80,
+};
+
+static const struct ad5110_cfg ad5110_cfg[] = {
+ [AD5110_10] = { .max_pos = 128, .kohms = 10 },
+ [AD5110_80] = { .max_pos = 128, .kohms = 80 },
+ [AD5112_05] = { .max_pos = 64, .kohms = 5, .shift = 1 },
+ [AD5112_10] = { .max_pos = 64, .kohms = 10, .shift = 1 },
+ [AD5112_80] = { .max_pos = 64, .kohms = 80, .shift = 1 },
+ [AD5114_10] = { .max_pos = 32, .kohms = 10, .shift = 2 },
+ [AD5114_80] = { .max_pos = 32, .kohms = 80, .shift = 2 },
+};
+
+struct ad5110_data {
+ struct i2c_client *client;
+ s16 tol; /* resistor tolerance */
+ bool enable;
+ struct mutex lock;
+ const struct ad5110_cfg *cfg;
+ /*
+ * DMA (thus cache coherency maintenance) requires the
+ * transfer buffers to live in their own cache lines.
+ */
+ u8 buf[2] ____cacheline_aligned;
+};
+
+static const struct iio_chan_spec ad5110_channels[] = {
+ {
+ .type = IIO_RESISTANCE,
+ .output = 1,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_OFFSET) |
+ BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_ENABLE),
+ }
+};
+
+static int ad5110_read(struct ad5110_data *data, u8 cmd, int *val)
+{
+ int ret;
+
+ mutex_lock(&data->lock);
+ data->buf[0] = cmd;
+ data->buf[1] = *val;
+
+ ret = i2c_master_send_dmasafe(data->client, data->buf, sizeof(data->buf));
+ if (ret != sizeof(data->buf)) {
+ ret = -EIO;
+ goto error;
+ }
+
+ ret = i2c_master_recv_dmasafe(data->client, data->buf, 1);
+ if (ret != 1) {
+ ret = -EIO;
+ goto error;
+ }
+
+ *val = data->buf[0];
+ ret = 0;
+
+error:
+ mutex_unlock(&data->lock);
+ return ret;
+}
+
+static int ad5110_write(struct ad5110_data *data, u8 cmd, u8 val)
+{
+ int ret;
+
+ mutex_lock(&data->lock);
+ data->buf[0] = cmd;
+ data->buf[1] = val;
+
+ ret = i2c_master_send_dmasafe(data->client, data->buf, sizeof(data->buf));
+ if (ret != sizeof(data->buf))
+ ret = -EIO;
+
+ mutex_unlock(&data->lock);
+
+ return ret < 0 ? ret : 0;
+}
+
+static int ad5110_resistor_tol(struct ad5110_data *data, u8 cmd, int val)
+{
+ int ret;
+
+ ret = ad5110_read(data, cmd, &val);
+ if (ret)
+ return ret;
+
+ data->tol = data->cfg->kohms * (val & GENMASK(6, 0)) * 10 / 8;
+ if (!(val & BIT(7)))
+ data->tol *= -1;
+
+ return 0;
+}
+
+static ssize_t ad5110_eeprom_read(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct ad5110_data *data = iio_priv(indio_dev);
+ int val = AD5110_WIPER_POS;
+ int ret;
+
+ ret = ad5110_read(data, AD5110_EEPROM_RD, &val);
+ if (ret)
+ return ret;
+
+ val = val >> data->cfg->shift;
+ return iio_format_value(buf, IIO_VAL_INT, 1, &val);
+}
+
+static ssize_t ad5110_eeprom_write(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct ad5110_data *data = iio_priv(indio_dev);
+ int ret;
+
+ ret = ad5110_write(data, AD5110_EEPROM_WR, 0);
+ if (ret) {
+ dev_err(&data->client->dev, "RDAC to EEPROM write failed\n");
+ return ret;
+ }
+ msleep(20);
+
+ return len;
+}
+
+static IIO_DEVICE_ATTR(store_eeprom, 0644,
+ ad5110_eeprom_read,
+ ad5110_eeprom_write, 0);
+
+static struct attribute *ad5110_attributes[] = {
+ &iio_dev_attr_store_eeprom.dev_attr.attr,
+ NULL,
+};
+
+static const struct attribute_group ad5110_attribute_group = {
+ .attrs = ad5110_attributes,
+};
+
+static int ad5110_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct ad5110_data *data = iio_priv(indio_dev);
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ ret = ad5110_read(data, AD5110_RDAC_RD, val);
+ if (ret)
+ return ret;
+
+ *val = *val >> data->cfg->shift;
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_OFFSET:
+ *val = WIPER_RESISTANCE * data->cfg->max_pos;
+ *val2 = 1000 * data->cfg->kohms + data->tol;
+ return IIO_VAL_FRACTIONAL;
+ case IIO_CHAN_INFO_SCALE:
+ *val = 1000 * data->cfg->kohms + data->tol;
+ *val2 = data->cfg->max_pos;
+ return IIO_VAL_FRACTIONAL;
+ case IIO_CHAN_INFO_ENABLE:
+ *val = data->enable;
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ad5110_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val, int val2, long mask)
+{
+ struct ad5110_data *data = iio_priv(indio_dev);
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ if (val > data->cfg->max_pos || val < 0)
+ return -EINVAL;
+
+ return ad5110_write(data, AD5110_RDAC_WR, val << data->cfg->shift);
+ case IIO_CHAN_INFO_ENABLE:
+ if (val < 0 || val > 1)
+ return -EINVAL;
+ if (data->enable == val)
+ return 0;
+ ret = ad5110_write(data, AD5110_SHUTDOWN, val ? 0 : 1);
+ if (ret)
+ return ret;
+ data->enable = val;
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct iio_info ad5110_info = {
+ .read_raw = ad5110_read_raw,
+ .write_raw = ad5110_write_raw,
+ .attrs = &ad5110_attribute_group,
+};
+
+#define AD5110_COMPATIBLE(of_compatible, cfg) { \
+ .compatible = of_compatible, \
+ .data = &ad5110_cfg[cfg], \
+}
+
+static const struct of_device_id ad5110_of_match[] = {
+ AD5110_COMPATIBLE("adi,ad5110-10", AD5110_10),
+ AD5110_COMPATIBLE("adi,ad5110-80", AD5110_80),
+ AD5110_COMPATIBLE("adi,ad5112-05", AD5112_05),
+ AD5110_COMPATIBLE("adi,ad5112-10", AD5112_10),
+ AD5110_COMPATIBLE("adi,ad5112-80", AD5112_80),
+ AD5110_COMPATIBLE("adi,ad5114-10", AD5114_10),
+ AD5110_COMPATIBLE("adi,ad5114-80", AD5114_80),
+ { }
+};
+MODULE_DEVICE_TABLE(of, ad5110_of_match);
+
+static const struct i2c_device_id ad5110_id[] = {
+ { "ad5110-10", AD5110_10 },
+ { "ad5110-80", AD5110_80 },
+ { "ad5112-05", AD5112_05 },
+ { "ad5112-10", AD5112_10 },
+ { "ad5112-80", AD5112_80 },
+ { "ad5114-10", AD5114_10 },
+ { "ad5114-80", AD5114_80 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, ad5110_id);
+
+static int ad5110_probe(struct i2c_client *client)
+{
+ struct device *dev = &client->dev;
+ struct iio_dev *indio_dev;
+ struct ad5110_data *data;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ data = iio_priv(indio_dev);
+ data->client = client;
+ mutex_init(&data->lock);
+ data->enable = 1;
+ data->cfg = device_get_match_data(dev);
+ if (!data->cfg)
+ data->cfg = &ad5110_cfg[i2c_match_id(ad5110_id, client)->driver_data];
+
+ /* refresh RDAC register with EEPROM */
+ ret = ad5110_write(data, AD5110_RESET, 0);
+ if (ret) {
+ dev_err(dev, "Refresh RDAC with EEPROM failed\n");
+ return ret;
+ }
+
+ ret = ad5110_resistor_tol(data, AD5110_EEPROM_RD, AD5110_RESISTOR_TOL);
+ if (ret) {
+ dev_err(dev, "Read resistor tolerance failed\n");
+ return ret;
+ }
+
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->info = &ad5110_info;
+ indio_dev->channels = ad5110_channels;
+ indio_dev->num_channels = ARRAY_SIZE(ad5110_channels);
+ indio_dev->name = client->name;
+
+ return devm_iio_device_register(dev, indio_dev);
+}
+
+static struct i2c_driver ad5110_driver = {
+ .driver = {
+ .name = "ad5110",
+ .of_match_table = ad5110_of_match,
+ },
+ .probe_new = ad5110_probe,
+ .id_table = ad5110_id,
+};
+
+module_i2c_driver(ad5110_driver);
+
+MODULE_AUTHOR("Mugilraj Dhavachelvan <[email protected]>");
+MODULE_DESCRIPTION("AD5110 digital potentiometer");
+MODULE_LICENSE("GPL v2");
+
--
2.25.1
On Mon, 9 Aug 2021 13:27:20 +0530
Mugilraj Dhavachelvan <[email protected]> wrote:
> The AD5110/AD5112/AD5114 provide a nonvolatile solution
> for 128-/64-/32-position adjustment applications, offering
> guaranteed low resistor tolerance errors of ±8% and up to
> ±6 mA current density.
>
> Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/AD5110_5112_5114.pdf
> Signed-off-by: Mugilraj Dhavachelvan <[email protected]>
Looks good to me, but I'll leave it on the list for a little
while to give time for others to take another look.
Thanks,
Jonathan
> ---
> MAINTAINERS | 6 +
> drivers/iio/potentiometer/Kconfig | 10 +
> drivers/iio/potentiometer/Makefile | 1 +
> drivers/iio/potentiometer/ad5110.c | 339 +++++++++++++++++++++++++++++
> 4 files changed, 356 insertions(+)
> create mode 100644 drivers/iio/potentiometer/ad5110.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index bd7aff0c120f..cf6e73b87b6e 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -452,6 +452,12 @@ S: Maintained
> W: https://parisc.wiki.kernel.org/index.php/AD1889
> F: sound/pci/ad1889.*
>
> +AD5110 ANALOG DEVICES DIGITAL POTENTIOMETERS DRIVER
> +M: Mugilraj Dhavachelvan <[email protected]>
> +L: [email protected]
> +S: Supported
> +F: drivers/iio/potentiometer/ad5110.c
> +
> AD525X ANALOG DEVICES DIGITAL POTENTIOMETERS DRIVER
> M: Michael Hennerich <[email protected]>
> S: Supported
> diff --git a/drivers/iio/potentiometer/Kconfig b/drivers/iio/potentiometer/Kconfig
> index 4cac0173db8b..832df8da2bc6 100644
> --- a/drivers/iio/potentiometer/Kconfig
> +++ b/drivers/iio/potentiometer/Kconfig
> @@ -6,6 +6,16 @@
>
> menu "Digital potentiometers"
>
> +config AD5110
> + tristate "Analog Devices AD5110 and similar Digital Potentiometer driver"
> + depends on I2C
> + help
> + Say yes here to build support for the Analog Devices AD5110, AD5112
> + and AD5114 digital potentiometer chip.
> +
> + To compile this driver as a module, choose M here: the
> + module will be called ad5110.
> +
> config AD5272
> tristate "Analog Devices AD5272 and similar Digital Potentiometer driver"
> depends on I2C
> diff --git a/drivers/iio/potentiometer/Makefile b/drivers/iio/potentiometer/Makefile
> index 091adf3cdd0b..5ebb8e3bbd76 100644
> --- a/drivers/iio/potentiometer/Makefile
> +++ b/drivers/iio/potentiometer/Makefile
> @@ -4,6 +4,7 @@
> #
>
> # When adding new entries keep the list in alphabetical order
> +obj-$(CONFIG_AD5110) += ad5110.o
> obj-$(CONFIG_AD5272) += ad5272.o
> obj-$(CONFIG_DS1803) += ds1803.o
> obj-$(CONFIG_MAX5432) += max5432.o
> diff --git a/drivers/iio/potentiometer/ad5110.c b/drivers/iio/potentiometer/ad5110.c
> new file mode 100644
> index 000000000000..4ba76e968edb
> --- /dev/null
> +++ b/drivers/iio/potentiometer/ad5110.c
> @@ -0,0 +1,339 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Analog Devices AD5110 digital potentiometer driver
> + *
> + * Copyright (C) 2021 Mugilraj Dhavachelvan <[email protected]>
> + *
> + * Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/AD5110_5112_5114.pdf
> + *
> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/delay.h>
> +#include <linux/device.h>
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +
> +/* AD5110 commands */
> +#define AD5110_EEPROM_WR 1
> +#define AD5110_RDAC_WR 2
> +#define AD5110_SHUTDOWN 3
> +#define AD5110_RESET 4
> +#define AD5110_RDAC_RD 5
> +#define AD5110_EEPROM_RD 6
> +
> +/* AD5110_EEPROM_RD data */
> +#define AD5110_WIPER_POS 0
> +#define AD5110_RESISTOR_TOL 1
> +
> +#define WIPER_RESISTANCE 70
> +
> +struct ad5110_cfg {
> + int max_pos;
> + int kohms;
> + int shift;
> +};
> +
> +enum ad5110_type {
> + AD5110_10,
> + AD5110_80,
> + AD5112_05,
> + AD5112_10,
> + AD5112_80,
> + AD5114_10,
> + AD5114_80,
> +};
> +
> +static const struct ad5110_cfg ad5110_cfg[] = {
> + [AD5110_10] = { .max_pos = 128, .kohms = 10 },
> + [AD5110_80] = { .max_pos = 128, .kohms = 80 },
> + [AD5112_05] = { .max_pos = 64, .kohms = 5, .shift = 1 },
> + [AD5112_10] = { .max_pos = 64, .kohms = 10, .shift = 1 },
> + [AD5112_80] = { .max_pos = 64, .kohms = 80, .shift = 1 },
> + [AD5114_10] = { .max_pos = 32, .kohms = 10, .shift = 2 },
> + [AD5114_80] = { .max_pos = 32, .kohms = 80, .shift = 2 },
> +};
> +
> +struct ad5110_data {
> + struct i2c_client *client;
> + s16 tol; /* resistor tolerance */
> + bool enable;
> + struct mutex lock;
> + const struct ad5110_cfg *cfg;
> + /*
> + * DMA (thus cache coherency maintenance) requires the
> + * transfer buffers to live in their own cache lines.
> + */
> + u8 buf[2] ____cacheline_aligned;
> +};
> +
> +static const struct iio_chan_spec ad5110_channels[] = {
> + {
> + .type = IIO_RESISTANCE,
> + .output = 1,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_OFFSET) |
> + BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_ENABLE),
> + }
> +};
> +
> +static int ad5110_read(struct ad5110_data *data, u8 cmd, int *val)
> +{
> + int ret;
> +
> + mutex_lock(&data->lock);
> + data->buf[0] = cmd;
> + data->buf[1] = *val;
> +
> + ret = i2c_master_send_dmasafe(data->client, data->buf, sizeof(data->buf));
> + if (ret != sizeof(data->buf)) {
> + ret = -EIO;
> + goto error;
> + }
> +
> + ret = i2c_master_recv_dmasafe(data->client, data->buf, 1);
> + if (ret != 1) {
> + ret = -EIO;
> + goto error;
> + }
> +
> + *val = data->buf[0];
> + ret = 0;
> +
> +error:
> + mutex_unlock(&data->lock);
> + return ret;
> +}
> +
> +static int ad5110_write(struct ad5110_data *data, u8 cmd, u8 val)
> +{
> + int ret;
> +
> + mutex_lock(&data->lock);
> + data->buf[0] = cmd;
> + data->buf[1] = val;
> +
> + ret = i2c_master_send_dmasafe(data->client, data->buf, sizeof(data->buf));
> + if (ret != sizeof(data->buf))
> + ret = -EIO;
> +
> + mutex_unlock(&data->lock);
> +
> + return ret < 0 ? ret : 0;
> +}
> +
> +static int ad5110_resistor_tol(struct ad5110_data *data, u8 cmd, int val)
> +{
> + int ret;
> +
> + ret = ad5110_read(data, cmd, &val);
> + if (ret)
> + return ret;
> +
> + data->tol = data->cfg->kohms * (val & GENMASK(6, 0)) * 10 / 8;
> + if (!(val & BIT(7)))
> + data->tol *= -1;
> +
> + return 0;
> +}
> +
> +static ssize_t ad5110_eeprom_read(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> + struct ad5110_data *data = iio_priv(indio_dev);
> + int val = AD5110_WIPER_POS;
> + int ret;
> +
> + ret = ad5110_read(data, AD5110_EEPROM_RD, &val);
> + if (ret)
> + return ret;
> +
> + val = val >> data->cfg->shift;
> + return iio_format_value(buf, IIO_VAL_INT, 1, &val);
> +}
> +
> +static ssize_t ad5110_eeprom_write(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t len)
> +{
> + struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> + struct ad5110_data *data = iio_priv(indio_dev);
> + int ret;
> +
> + ret = ad5110_write(data, AD5110_EEPROM_WR, 0);
> + if (ret) {
> + dev_err(&data->client->dev, "RDAC to EEPROM write failed\n");
> + return ret;
> + }
> + msleep(20);
> +
> + return len;
> +}
> +
> +static IIO_DEVICE_ATTR(store_eeprom, 0644,
> + ad5110_eeprom_read,
> + ad5110_eeprom_write, 0);
> +
> +static struct attribute *ad5110_attributes[] = {
> + &iio_dev_attr_store_eeprom.dev_attr.attr,
> + NULL,
> +};
> +
> +static const struct attribute_group ad5110_attribute_group = {
> + .attrs = ad5110_attributes,
> +};
> +
> +static int ad5110_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int *val, int *val2, long mask)
> +{
> + struct ad5110_data *data = iio_priv(indio_dev);
> + int ret;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
> + ret = ad5110_read(data, AD5110_RDAC_RD, val);
> + if (ret)
> + return ret;
> +
> + *val = *val >> data->cfg->shift;
> + return IIO_VAL_INT;
> + case IIO_CHAN_INFO_OFFSET:
> + *val = WIPER_RESISTANCE * data->cfg->max_pos;
> + *val2 = 1000 * data->cfg->kohms + data->tol;
> + return IIO_VAL_FRACTIONAL;
> + case IIO_CHAN_INFO_SCALE:
> + *val = 1000 * data->cfg->kohms + data->tol;
> + *val2 = data->cfg->max_pos;
> + return IIO_VAL_FRACTIONAL;
> + case IIO_CHAN_INFO_ENABLE:
> + *val = data->enable;
> + return IIO_VAL_INT;
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static int ad5110_write_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int val, int val2, long mask)
> +{
> + struct ad5110_data *data = iio_priv(indio_dev);
> + int ret;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
> + if (val > data->cfg->max_pos || val < 0)
> + return -EINVAL;
> +
> + return ad5110_write(data, AD5110_RDAC_WR, val << data->cfg->shift);
> + case IIO_CHAN_INFO_ENABLE:
> + if (val < 0 || val > 1)
> + return -EINVAL;
> + if (data->enable == val)
> + return 0;
> + ret = ad5110_write(data, AD5110_SHUTDOWN, val ? 0 : 1);
> + if (ret)
> + return ret;
> + data->enable = val;
> + return 0;
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static const struct iio_info ad5110_info = {
> + .read_raw = ad5110_read_raw,
> + .write_raw = ad5110_write_raw,
> + .attrs = &ad5110_attribute_group,
> +};
> +
> +#define AD5110_COMPATIBLE(of_compatible, cfg) { \
> + .compatible = of_compatible, \
> + .data = &ad5110_cfg[cfg], \
> +}
> +
> +static const struct of_device_id ad5110_of_match[] = {
> + AD5110_COMPATIBLE("adi,ad5110-10", AD5110_10),
> + AD5110_COMPATIBLE("adi,ad5110-80", AD5110_80),
> + AD5110_COMPATIBLE("adi,ad5112-05", AD5112_05),
> + AD5110_COMPATIBLE("adi,ad5112-10", AD5112_10),
> + AD5110_COMPATIBLE("adi,ad5112-80", AD5112_80),
> + AD5110_COMPATIBLE("adi,ad5114-10", AD5114_10),
> + AD5110_COMPATIBLE("adi,ad5114-80", AD5114_80),
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, ad5110_of_match);
> +
> +static const struct i2c_device_id ad5110_id[] = {
> + { "ad5110-10", AD5110_10 },
> + { "ad5110-80", AD5110_80 },
> + { "ad5112-05", AD5112_05 },
> + { "ad5112-10", AD5112_10 },
> + { "ad5112-80", AD5112_80 },
> + { "ad5114-10", AD5114_10 },
> + { "ad5114-80", AD5114_80 },
> + { }
> +};
> +MODULE_DEVICE_TABLE(i2c, ad5110_id);
> +
> +static int ad5110_probe(struct i2c_client *client)
> +{
> + struct device *dev = &client->dev;
> + struct iio_dev *indio_dev;
> + struct ad5110_data *data;
> + int ret;
> +
> + indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
> + if (!indio_dev)
> + return -ENOMEM;
> +
> + data = iio_priv(indio_dev);
> + data->client = client;
> + mutex_init(&data->lock);
> + data->enable = 1;
> + data->cfg = device_get_match_data(dev);
> + if (!data->cfg)
> + data->cfg = &ad5110_cfg[i2c_match_id(ad5110_id, client)->driver_data];
> +
> + /* refresh RDAC register with EEPROM */
> + ret = ad5110_write(data, AD5110_RESET, 0);
> + if (ret) {
> + dev_err(dev, "Refresh RDAC with EEPROM failed\n");
> + return ret;
> + }
> +
> + ret = ad5110_resistor_tol(data, AD5110_EEPROM_RD, AD5110_RESISTOR_TOL);
> + if (ret) {
> + dev_err(dev, "Read resistor tolerance failed\n");
> + return ret;
> + }
> +
> + indio_dev->modes = INDIO_DIRECT_MODE;
> + indio_dev->info = &ad5110_info;
> + indio_dev->channels = ad5110_channels;
> + indio_dev->num_channels = ARRAY_SIZE(ad5110_channels);
> + indio_dev->name = client->name;
> +
> + return devm_iio_device_register(dev, indio_dev);
> +}
> +
> +static struct i2c_driver ad5110_driver = {
> + .driver = {
> + .name = "ad5110",
> + .of_match_table = ad5110_of_match,
> + },
> + .probe_new = ad5110_probe,
> + .id_table = ad5110_id,
> +};
> +
> +module_i2c_driver(ad5110_driver);
> +
> +MODULE_AUTHOR("Mugilraj Dhavachelvan <[email protected]>");
> +MODULE_DESCRIPTION("AD5110 digital potentiometer");
> +MODULE_LICENSE("GPL v2");
> +
On Mon, Aug 9, 2021 at 10:59 AM Mugilraj Dhavachelvan
<[email protected]> wrote:
>
> The AD5110/AD5112/AD5114 provide a nonvolatile solution
> for 128-/64-/32-position adjustment applications, offering
> guaranteed low resistor tolerance errors of ±8% and up to
> ±6 mA current density.
...
> +/*
> + * Analog Devices AD5110 digital potentiometer driver
> + *
> + * Copyright (C) 2021 Mugilraj Dhavachelvan <[email protected]>
> + *
> + * Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/AD5110_5112_5114.pdf
> + *
Redundant blank line.
> + */
...
> +#define WIPER_RESISTANCE 70
Missed prefix?
...
> +static const struct iio_chan_spec ad5110_channels[] = {
> + {
> + .type = IIO_RESISTANCE,
> + .output = 1,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_OFFSET) |
> + BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_ENABLE),
> + }
+ comma.
> +};
...
> + ret = i2c_master_send_dmasafe(data->client, data->buf, sizeof(data->buf));
> + if (ret != sizeof(data->buf)) {
> + ret = -EIO;
Shadowed error code when ret < 0.
> + goto error;
> + }
...
> + ret = i2c_master_send_dmasafe(data->client, data->buf, sizeof(data->buf));
> + if (ret != sizeof(data->buf))
> + ret = -EIO;
Ditto.
> + mutex_unlock(&data->lock);
> +
> + return ret < 0 ? ret : 0;
> +}
...
> + data->tol = data->cfg->kohms * (val & GENMASK(6, 0)) * 10 / 8;
> + if (!(val & BIT(7)))
> + data->tol *= -1;
Shouldn't you simple use corresponding sign_extend*()?
...
> + ret = ad5110_write(data, AD5110_EEPROM_WR, 0);
> + if (ret) {
> + dev_err(&data->client->dev, "RDAC to EEPROM write failed\n");
> + return ret;
> + }
> + msleep(20);
Each long sleeps like this must be explained.
...
> +static IIO_DEVICE_ATTR(store_eeprom, 0644,
> + ad5110_eeprom_read,
> + ad5110_eeprom_write, 0);
IIO_DEVICE_ATTR_RW() ?
...
> +static struct attribute *ad5110_attributes[] = {
> + &iio_dev_attr_store_eeprom.dev_attr.attr,
> + NULL,
No comma for a terminator line.
> +};
...
> + data->cfg = device_get_match_data(dev);
> + if (!data->cfg)
> + data->cfg = &ad5110_cfg[i2c_match_id(ad5110_id, client)->driver_data];
Not sure this is not a dead code since you are using ->probe_new().
...
> +static struct i2c_driver ad5110_driver = {
> + .driver = {
> + .name = "ad5110",
> + .of_match_table = ad5110_of_match,
> + },
> + .probe_new = ad5110_probe,
> + .id_table = ad5110_id,
> +};
> +
Redundant blank line.
> +module_i2c_driver(ad5110_driver);
--
With Best Regards,
Andy Shevchenko
On Tue, Aug 10, 2021 at 03:49:52PM +0300, Andy Shevchenko wrote:
> On Mon, Aug 9, 2021 at 10:59 AM Mugilraj Dhavachelvan
> <[email protected]> wrote:
> >
> > The AD5110/AD5112/AD5114 provide a nonvolatile solution
> > for 128-/64-/32-position adjustment applications, offering
> > guaranteed low resistor tolerance errors of ?8% and up to
> > ?6 mA current density.
>
> ...
>
> > +/*
> > + * Analog Devices AD5110 digital potentiometer driver
> > + *
> > + * Copyright (C) 2021 Mugilraj Dhavachelvan <[email protected]>
> > + *
> > + * Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/AD5110_5112_5114.pdf
>
> > + *
>
> Redundant blank line.
>
fixed in v3
> > + */
>
> ...
>
> > +#define WIPER_RESISTANCE 70
>
> Missed prefix?
>
fixed in v3
> ...
>
> > +static const struct iio_chan_spec ad5110_channels[] = {
> > + {
> > + .type = IIO_RESISTANCE,
> > + .output = 1,
> > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_OFFSET) |
> > + BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_ENABLE),
> > + }
>
> + comma.
>
fixed in v3
> > +};
>
> ...
>
> > + ret = i2c_master_send_dmasafe(data->client, data->buf, sizeof(data->buf));
> > + if (ret != sizeof(data->buf)) {
>
> > + ret = -EIO;
>
> Shadowed error code when ret < 0.
>
fixed in v3
> > + goto error;
> > + }
>
> ...
>
> > + ret = i2c_master_send_dmasafe(data->client, data->buf, sizeof(data->buf));
> > + if (ret != sizeof(data->buf))
> > + ret = -EIO;
>
> Ditto.
>
fixed in v3
> > + mutex_unlock(&data->lock);
> > +
> > + return ret < 0 ? ret : 0;
> > +}
>
> ...
>
> > + data->tol = data->cfg->kohms * (val & GENMASK(6, 0)) * 10 / 8;
> > + if (!(val & BIT(7)))
> > + data->tol *= -1;
>
> Shouldn't you simple use corresponding sign_extend*()?
>
I'm not able see any sign_extend for 16 bit. Is there any other way?
> ...
>
> > + ret = ad5110_write(data, AD5110_EEPROM_WR, 0);
> > + if (ret) {
> > + dev_err(&data->client->dev, "RDAC to EEPROM write failed\n");
> > + return ret;
> > + }
>
>
> > + msleep(20);
>
> Each long sleeps like this must be explained.
>
fixed in v3
> ...
>
> > +static IIO_DEVICE_ATTR(store_eeprom, 0644,
> > + ad5110_eeprom_read,
> > + ad5110_eeprom_write, 0);
>
> IIO_DEVICE_ATTR_RW() ?
>
fixed in v3
> ...
>
> > +static struct attribute *ad5110_attributes[] = {
> > + &iio_dev_attr_store_eeprom.dev_attr.attr,
> > + NULL,
>
> No comma for a terminator line.
>
fixed in v3
> > +};
>
> ...
>
> > + data->cfg = device_get_match_data(dev);
>
> > + if (!data->cfg)
> > + data->cfg = &ad5110_cfg[i2c_match_id(ad5110_id, client)->driver_data];
>
> Not sure this is not a dead code since you are using ->probe_new().
>
Even I'm suspecting that and also removing id_table. But I'm not sure of
it so just left as it is.
> ...
>
> > +static struct i2c_driver ad5110_driver = {
> > + .driver = {
> > + .name = "ad5110",
> > + .of_match_table = ad5110_of_match,
> > + },
> > + .probe_new = ad5110_probe,
> > + .id_table = ad5110_id,
> > +};
>
> > +
>
> Redundant blank line
fixed in v3.
>
> > +module_i2c_driver(ad5110_driver);
>
Thanks for the feedback :)
> --
> With Best Regards,
> Andy Shevchenko
On Wed, Aug 11, 2021 at 8:46 AM Mugilraj Dhavachelvan
<[email protected]> wrote:
> On Tue, Aug 10, 2021 at 03:49:52PM +0300, Andy Shevchenko wrote:
> > On Mon, Aug 9, 2021 at 10:59 AM Mugilraj Dhavachelvan
> > <[email protected]> wrote:
...
> > > + data->tol = data->cfg->kohms * (val & GENMASK(6, 0)) * 10 / 8;
> > > + if (!(val & BIT(7)))
> > > + data->tol *= -1;
> >
> > Shouldn't you simple use corresponding sign_extend*()?
> >
> I'm not able see any sign_extend for 16 bit. Is there any other way?
So, then add it in bitops.h the same way it's done for s32 and s64.
...
> > > + if (!data->cfg)
> > > + data->cfg = &ad5110_cfg[i2c_match_id(ad5110_id, client)->driver_data];
> >
> > Not sure this is not a dead code since you are using ->probe_new().
> >
> Even I'm suspecting that and also removing id_table. But I'm not sure of
> it so just left as it is.
I²C ID table is good to have without direct use, but ->probe_new() is
called if and only if there is a compatible string or ACPI ID match.
In such case data->cfg may be NULL if and only if the corresponding
table missed it, but this will be a bug anyway, so the above code will
rather hide the bug. Hence, please remove it.
--
With Best Regards,
Andy Shevchenko
On Wed, Aug 11, 2021 at 10:03 AM Andy Shevchenko
<[email protected]> wrote:
> On Wed, Aug 11, 2021 at 8:46 AM Mugilraj Dhavachelvan
> <[email protected]> wrote:
> > On Tue, Aug 10, 2021 at 03:49:52PM +0300, Andy Shevchenko wrote:
> > > On Mon, Aug 9, 2021 at 10:59 AM Mugilraj Dhavachelvan
> > > <[email protected]> wrote:
>
> ...
>
> > > > + data->tol = data->cfg->kohms * (val & GENMASK(6, 0)) * 10 / 8;
> > > > + if (!(val & BIT(7)))
> > > > + data->tol *= -1;
> > >
> > > Shouldn't you simple use corresponding sign_extend*()?
> > >
> > I'm not able see any sign_extend for 16 bit. Is there any other way?
>
> So, then add it in bitops.h the same way it's done for s32 and s64.
In case you are afraid that this will delay patches and you are in a
hurry, you may define it locally (but in the very same way, so
somebody can make it generic). Nevertheless, I think this one can be
added directly to the generic header, it will definitely have more
than one user.
> ...
>
> > > > + if (!data->cfg)
> > > > + data->cfg = &ad5110_cfg[i2c_match_id(ad5110_id, client)->driver_data];
> > >
> > > Not sure this is not a dead code since you are using ->probe_new().
> > >
> > Even I'm suspecting that and also removing id_table. But I'm not sure of
> > it so just left as it is.
>
> I²C ID table is good to have without direct use, but ->probe_new() is
> called if and only if there is a compatible string or ACPI ID match.
> In such case data->cfg may be NULL if and only if the corresponding
> table missed it, but this will be a bug anyway, so the above code will
> rather hide the bug. Hence, please remove it.
--
With Best Regards,
Andy Shevchenko
On Wed, Aug 11, 2021 at 10:05:41AM +0300, Andy Shevchenko wrote:
> On Wed, Aug 11, 2021 at 10:03 AM Andy Shevchenko
> <[email protected]> wrote:
> > On Wed, Aug 11, 2021 at 8:46 AM Mugilraj Dhavachelvan
> > <[email protected]> wrote:
> > > On Tue, Aug 10, 2021 at 03:49:52PM +0300, Andy Shevchenko wrote:
> > > > On Mon, Aug 9, 2021 at 10:59 AM Mugilraj Dhavachelvan
> > > > <[email protected]> wrote:
> >
> > ...
> >
> > > > > + data->tol = data->cfg->kohms * (val & GENMASK(6, 0)) * 10 / 8;
> > > > > + if (!(val & BIT(7)))
> > > > > + data->tol *= -1;
> > > >
> > > > Shouldn't you simple use corresponding sign_extend*()?
> > > >
> > > I'm not able see any sign_extend for 16 bit. Is there any other way?
> >
> > So, then add it in bitops.h the same way it's done for s32 and s64.
>
> In case you are afraid that this will delay patches and you are in a
> hurry, you may define it locally (but in the very same way, so
> somebody can make it generic). Nevertheless, I think this one can be
> added directly to the generic header, it will definitely have more
> than one user.
>
It seems like we can use sign_extend32() for 16 and 8 bit as well.
> > ...
> >
> > > > > + if (!data->cfg)
> > > > > + data->cfg = &ad5110_cfg[i2c_match_id(ad5110_id, client)->driver_data];
> > > >
> > > > Not sure this is not a dead code since you are using ->probe_new().
> > > >
> > > Even I'm suspecting that and also removing id_table. But I'm not sure of
> > > it so just left as it is.
> >
> > I?C ID table is good to have without direct use, but ->probe_new() is
> > called if and only if there is a compatible string or ACPI ID match.
> > In such case data->cfg may be NULL if and only if the corresponding
> > table missed it, but this will be a bug anyway, so the above code will
> > rather hide the bug. Hence, please remove it.
>
>
>
> --
> With Best Regards,
> Andy Shevchenko
On 8/10/21 2:49 PM, Andy Shevchenko wrote:
>
>> + data->tol = data->cfg->kohms * (val & GENMASK(6, 0)) * 10 / 8;
>> + if (!(val & BIT(7)))
>> + data->tol *= -1;
> Shouldn't you simple use corresponding sign_extend*()?
The data is encoded a sign-magnitude. sign_extend() works for two's
complement numbers.
On Wed, Aug 11, 2021 at 11:15 AM Lars-Peter Clausen <[email protected]> wrote:
> On 8/10/21 2:49 PM, Andy Shevchenko wrote:
> >
> >> + data->tol = data->cfg->kohms * (val & GENMASK(6, 0)) * 10 / 8;
> >> + if (!(val & BIT(7)))
> >> + data->tol *= -1;
> > Shouldn't you simple use corresponding sign_extend*()?
> The data is encoded a sign-magnitude. sign_extend() works for two's
> complement numbers.
Good catch!
I'm wondering if it's a good idea to have a sign_magnitude_to_int()
helper or so?
--
With Best Regards,
Andy Shevchenko
On Wed, Aug 11, 2021 at 07:06:43PM +0300, Andy Shevchenko wrote:
> On Wed, Aug 11, 2021 at 11:15 AM Lars-Peter Clausen <[email protected]> wrote:
> > On 8/10/21 2:49 PM, Andy Shevchenko wrote:
> > >
> > >> + data->tol = data->cfg->kohms * (val & GENMASK(6, 0)) * 10 / 8;
> > >> + if (!(val & BIT(7)))
> > >> + data->tol *= -1;
> > > Shouldn't you simple use corresponding sign_extend*()?
> > The data is encoded a sign-magnitude. sign_extend() works for two's
> > complement numbers.
>
> Good catch!
> I'm wondering if it's a good idea to have a sign_magnitude_to_int()
> helper or so?
>
So, What should I do now?
> --
> With Best Regards,
> Andy Shevchenko
On Thu, Aug 12, 2021 at 10:23:41PM +0530, Mugilraj Dhavachelvan wrote:
> On Wed, Aug 11, 2021 at 07:06:43PM +0300, Andy Shevchenko wrote:
> > On Wed, Aug 11, 2021 at 11:15 AM Lars-Peter Clausen <[email protected]> wrote:
> > > On 8/10/21 2:49 PM, Andy Shevchenko wrote:
> > > >
> > > >> + data->tol = data->cfg->kohms * (val & GENMASK(6, 0)) * 10 / 8;
> > > >> + if (!(val & BIT(7)))
> > > >> + data->tol *= -1;
> > > > Shouldn't you simple use corresponding sign_extend*()?
> > > The data is encoded a sign-magnitude. sign_extend() works for two's
> > > complement numbers.
> >
> > Good catch!
> > I'm wondering if it's a good idea to have a sign_magnitude_to_int()
> > helper or so?
> >
> So, What should I do now?
>
Will send v3 with other changes and add this change in v4. Hope it's
okay.
> > --
> > With Best Regards,
> > Andy Shevchenko