[2/2] iio: potentiometer: Add driver support for AD5110

Message ID	20210807050900.10075-3-dmugil2000@gmail.com (mailing list archive)
State	Changes Requested
Headers	show Return-Path: <linux-iio-owner@kernel.org> From: Mugilraj Dhavachelvan <dmugil2000@gmail.com> To: Dragos.Bogdan@analog.com, Darius.Berghe@analog.com, Rob Herring <robh+dt@kernel.org>, Jonathan Cameron <jic23@kernel.org>, Lars-Peter Clausen <lars@metafoo.de>, Michael Hennerich <Michael.Hennerich@analog.com>, Mugilraj Dhavachelvan <dmugil2000@gmail.com>, Guenter Roeck <linux@roeck-us.net>, Chris Packham <chris.packham@alliedtelesis.co.nz>, Alexandre Belloni <alexandre.belloni@bootlin.com>, Krzysztof Kozlowski <krzk@kernel.org>, Alexandru Ardelean <alexandru.ardelean@analog.com>, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org Subject: [PATCH 2/2] iio: potentiometer: Add driver support for AD5110 Date: Sat, 7 Aug 2021 10:38:55 +0530 Message-Id: <20210807050900.10075-3-dmugil2000@gmail.com> In-Reply-To: <20210807050900.10075-1-dmugil2000@gmail.com> References: <20210807050900.10075-1-dmugil2000@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	iio: potentiometer: Add driver support for AD5110 \| expand [0/2] iio: potentiometer: Add driver support for AD5110 [1/2] dt-bindings: iio: potentiometer: Add AD5110 in trivial-devices [2/2] iio: potentiometer: Add driver support for AD5110

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@gmail.com> +L: linux-iio@vger.kernel.org +S: Supported +F: drivers/iio/potentiometer/ad5110.c + AD525X ANALOG DEVICES DIGITAL POTENTIOMETERS DRIVER M: Michael Hennerich <michael.hennerich@analog.com> 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..26eb7a7aa15b --- /dev/null +++ b/drivers/iio/potentiometer/ad5110.c @@ -0,0 +1,333 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Analog Devices AD5110 digital potentiometer driver + * + * Copyright (C) 2021 Mugilraj Dhavachelvan <dmugil2000@gmail.com> + * + * 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), + .info_mask_shared_by_type = 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; + + ret = i2c_master_recv_dmasafe(data->client, data->buf, 1); + if (ret < 0) + 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)); + 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 = FIELD_GET(GENMASK(6, 3), val); + data->tol = ((val & GENMASK(2, 0)) * 1000 / 8) + data->tol * 1000; + data->tol = data->cfg->kohms * data->tol / 100; + 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; + + 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(wiper_pos_eeprom, 0644, + ad5110_eeprom_read, + ad5110_eeprom_write, 0); + +static struct attribute *ad5110_attributes[] = { + &iio_dev_attr_wiper_pos_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); + 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->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 <dmugil2000@gmail.com>"); +MODULE_DESCRIPTION("AD5110 digital potentiometer"); +MODULE_LICENSE("GPL v2"); +

[2/2] iio: potentiometer: Add driver support for AD5110

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