On Sat, Aug 14, 2021 at 8:57 PM Mugilraj Dhavachelvan <dmugil2000@xxxxxxxxx> 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. Looks good enough to me, thanks! Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx> > Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/AD5110_5112_5114.pdf > Signed-off-by: Mugilraj Dhavachelvan <dmugil2000@xxxxxxxxx> > --- > MAINTAINERS | 6 + > drivers/iio/potentiometer/Kconfig | 10 + > drivers/iio/potentiometer/Makefile | 1 + > drivers/iio/potentiometer/ad5110.c | 345 +++++++++++++++++++++++++++++ > 4 files changed, 362 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 <dmugil2000@xxxxxxxxx> > +L: linux-iio@xxxxxxxxxxxxxxx > +S: Supported > +F: drivers/iio/potentiometer/ad5110.c > + > AD525X ANALOG DEVICES DIGITAL POTENTIOMETERS DRIVER > M: Michael Hennerich <michael.hennerich@xxxxxxxxxx> > 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..ae18f9e115b2 > --- /dev/null > +++ b/drivers/iio/potentiometer/ad5110.c > @@ -0,0 +1,345 @@ > +// SPDX-License-Identifier: GPL-2.0+ > +/* > + * Analog Devices AD5110 digital potentiometer driver > + * > + * Copyright (C) 2021 Mugilraj Dhavachelvan <dmugil2000@xxxxxxxxx> > + * > + * 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 AD5110_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 < 0) { > + goto error; > + } else if (ret != sizeof(data->buf)) { > + ret = -EIO; > + goto error; > + } > + > + ret = i2c_master_recv_dmasafe(data->client, data->buf, 1); > + if (ret < 0) { > + goto error; > + } else 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 < 0) { > + goto error; > + } else if (ret != sizeof(data->buf)) { > + ret = -EIO; > + goto error; > + } > + > + ret = 0; > + > +error: > + mutex_unlock(&data->lock); > + return ret; > +} > + > +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 store_eeprom_show(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 store_eeprom_store(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; > + } > + > + /* The storing of EEPROM data takes approximately 18 ms. */ > + msleep(20); > + > + return len; > +} > + > +static IIO_DEVICE_ATTR_RW(store_eeprom, 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 = AD5110_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); > + > + /* 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 <dmugil2000@xxxxxxxxx>"); > +MODULE_DESCRIPTION("AD5110 digital potentiometer"); > +MODULE_LICENSE("GPL v2"); > + > -- > 2.25.1 > -- With Best Regards, Andy Shevchenko
