The AS5600 is a Hall-based rotary magnetic position sensor using planar sensors that convert the magnetic field component perpendicular to the surface of the chip into a voltage, or a numerical value available through i2c. The driver registers the chip as an IIO_ANGL device. It also exposes the various registers through sysfs. Signed-off-by: frank zago <frank@xxxxxxxx> --- I'm not certain the values the driver return to IIO are correct. The angle returned by the chip is a value in 0..4095, and that's what the driver returns. The sysfs doc says it should be in radian. Also it's unclear to me how I should define the scale. .../ABI/testing/sysfs-bus-iio-position-as5600 | 38 +++ drivers/iio/position/Kconfig | 10 + drivers/iio/position/Makefile | 1 + drivers/iio/position/as5600.c | 309 ++++++++++++++++++ 4 files changed, 358 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-position-as5600 create mode 100644 drivers/iio/position/as5600.c diff --git a/Documentation/ABI/testing/sysfs-bus-iio-position-as5600 b/Documentation/ABI/testing/sysfs-bus-iio-position-as5600 new file mode 100644 index 000000000000..d0d9c794529b --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-iio-position-as5600 @@ -0,0 +1,38 @@ +What: sys/bus/iio/devices/iio:deviceX/in_angl0_raw +KernelVersion: TBD +Contact: linux-iio@xxxxxxxxxxxxxxx +Description: + Returns the unscaled and unmodified angle + +What: sys/bus/iio/devices/iio:deviceX/in_angl1_raw +KernelVersion: TBD +Contact: linux-iio@xxxxxxxxxxxxxxx +Description: + Returns the scaled and modified angle, as affected by the + zpos/mpos/mang values. + +What: sys/bus/iio/devices/iio:deviceX/agc +What: sys/bus/iio/devices/iio:deviceX/conf_fth +What: sys/bus/iio/devices/iio:deviceX/conf_hyst +What: sys/bus/iio/devices/iio:deviceX/conf_outs +What: sys/bus/iio/devices/iio:deviceX/conf_pm +What: sys/bus/iio/devices/iio:deviceX/conf_pwmf +What: sys/bus/iio/devices/iio:deviceX/conf_sf +What: sys/bus/iio/devices/iio:deviceX/conf_wd +What: sys/bus/iio/devices/iio:deviceX/magnitude +What: sys/bus/iio/devices/iio:deviceX/mang +What: sys/bus/iio/devices/iio:deviceX/mpos +What: sys/bus/iio/devices/iio:deviceX/status_md +What: sys/bus/iio/devices/iio:deviceX/status_mh +What: sys/bus/iio/devices/iio:deviceX/status_ml +What: sys/bus/iio/devices/iio:deviceX/zmco +What: sys/bus/iio/devices/iio:deviceX/zpos +KernelVersion: TBD +Contact: linux-iio@xxxxxxxxxxxxxxx +Description: + Read and write the ams AS5600 internal registers and their + fields. zpos/mpos can be used to create a subset of the 0-360 + degree range. status_md will tell whether the magnet is + detected. Check the datasheet + (https://ams.com/documents/20143/36005/AS5600_DS000365_5-00.pdf) + for more information. diff --git a/drivers/iio/position/Kconfig b/drivers/iio/position/Kconfig index 1576a6380b53..111ed551ae79 100644 --- a/drivers/iio/position/Kconfig +++ b/drivers/iio/position/Kconfig @@ -6,6 +6,16 @@ menu "Linear and angular position sensors" +config AS5600 + tristate "ams AS5600 angular position sensor" + depends on I2C + help + Say Y here if you want to build support for the ams 5600 + 12-Bit Programmable Contactless Potentiometer. + + To compile this driver as a module, choose M here: the module + will be called as5600. + config IQS624_POS tristate "Azoteq IQS624/625 angular position sensors" depends on MFD_IQS62X || COMPILE_TEST diff --git a/drivers/iio/position/Makefile b/drivers/iio/position/Makefile index d70902f2979d..53930681e6a4 100644 --- a/drivers/iio/position/Makefile +++ b/drivers/iio/position/Makefile @@ -4,5 +4,6 @@ # When adding new entries keep the list in alphabetical order +obj-$(CONFIG_AS5600) += as5600.o obj-$(CONFIG_HID_SENSOR_CUSTOM_INTEL_HINGE) += hid-sensor-custom-intel-hinge.o obj-$(CONFIG_IQS624_POS) += iqs624-pos.o diff --git a/drivers/iio/position/as5600.c b/drivers/iio/position/as5600.c new file mode 100644 index 000000000000..2b160fd3a795 --- /dev/null +++ b/drivers/iio/position/as5600.c @@ -0,0 +1,309 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * ams AS5600 -- 12-Bit Programmable Contactless Potentiometer + * + * Copyright 2021, Frank Zago + * + * datasheet v1.06 (2018-Jun-20): + * https://ams.com/documents/20143/36005/AS5600_DS000365_5-00.pdf + * + * The rotating magnet is installed from 0.5mm to 3mm parallel to and + * above the chip. + * + * The raw angle value returned by the chip is [0..4095]. The channel + * 0 (in_angl0_raw) returns the unscaled and unmodified angle, always + * covering the 360 degrees. The channel 1 returns the chip adjusted + * angle, covering from 18 to 360 degrees, as modified by its + * ZPOS/MPOS/MANG values, + * + * ZPOS and MPOS can be programmed through their sysfs entries. The + * MANG register doesn't appear to be programmable without flashing + * the chip. + * + * If the DIR pin is grounded, angles will increase when the magnet is + * turned clockwise. If DIR is connected to Vcc, it will be the opposite. + * + * Permanent programming of the MPOS/ZPOS/MANG/CONF registers is not + * implemented. + * + * The i2c address of the device is 0x36. + */ + +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> +#include <linux/i2c.h> +#include <linux/delay.h> + +/* Registers and their fields, as defined in the datasheet */ +#define REG_ZMCO 0x00 +#define REG_ZMCO_ZMCO GENMASK(1, 0) +#define REG_ZPOS 0x01 +#define REG_ZPOS_ZPOS GENMASK(11, 0) +#define REG_MPOS 0x03 +#define REG_MPOS_MPOS GENMASK(11, 0) +#define REG_MANG 0x05 +#define REG_MANG_MANG GENMASK(11, 0) +#define REG_CONF 0x07 +#define REG_CONF_PM GENMASK(1, 0) +#define REG_CONF_HYST GENMASK(3, 2) +#define REG_CONF_OUTS GENMASK(5, 4) +#define REG_CONF_PWMF GENMASK(7, 6) +#define REG_CONF_SF GENMASK(9, 8) +#define REG_CONF_FTH GENMASK(12, 10) +#define REG_CONF_WD BIT(13) +#define REG_STATUS 0x0b +#define REG_STATUS_MH BIT(3) +#define REG_STATUS_ML BIT(4) +#define REG_STATUS_MD BIT(5) +#define REG_RAW_ANGLE 0x0c +#define REG_RAW_ANGLE_ANGLE GENMASK(11, 0) +#define REG_ANGLE 0x0e +#define REG_ANGLE_ANGLE GENMASK(11, 0) +#define REG_AGC 0x1a +#define REG_AGC_AGC GENMASK(7, 0) +#define REG_MAGNITUDE 0x1b +#define REG_MAGNITUDE_MAGNITUDE GENMASK(11, 0) +#define REG_BURN 0xff + +/* To simplify some code, the register index and each fields bitmask + * are encoded in the address field of the sysfs attributes and + * iio_chan_spec. field_get and field_prep are runtime versions of the + * FIELD_GET/FIELD_PREP macros. + */ +#define field_get(_mask, _reg) (((_reg) & (_mask)) >> (ffs(_mask) - 1)) +#define field_prep(_mask, _val) (((_val) << (ffs(_mask) - 1)) & (_mask)) + +#define to_address(reg, field) ((REG_##reg << 16) | REG_##reg##_##field) +#define reg_from_address(address) (address >> 16) +#define mask_from_address(address) (address & 0xffff) + +struct as5600_priv { + struct iio_dev *iio_dev; + struct i2c_client *client; +}; + +static int as5600_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct as5600_priv *priv = iio_priv(indio_dev); + u16 bitmask; + s32 angle; + u16 reg; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + reg = reg_from_address(chan->address); + bitmask = mask_from_address(chan->address); + angle = i2c_smbus_read_word_swapped(priv->client, reg); + if (angle < 0) + return angle; + *val = field_get(bitmask, angle); + + return IIO_VAL_INT; + + case IIO_CHAN_INFO_SCALE: + *val = 4095; + + return IIO_VAL_INT; + + default: + return -EINVAL; + } +} + +static ssize_t rs5600_attr_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev)); + struct as5600_priv *priv = iio_priv(indio_dev); + struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); + unsigned int reg = reg_from_address(this_attr->address); + unsigned int mask = mask_from_address(this_attr->address); + int ret; + + switch (reg) { + case REG_ZMCO: + case REG_STATUS: + case REG_AGC: + ret = i2c_smbus_read_byte_data(priv->client, reg); + if (ret < 0) + return ret; + return sysfs_emit(buf, "%u\n", field_get(mask, ret)); + + case REG_ZPOS: + case REG_MPOS: + case REG_MANG: + case REG_CONF: + case REG_MAGNITUDE: + ret = i2c_smbus_read_word_swapped(priv->client, reg); + if (ret < 0) + return ret; + return sysfs_emit(buf, "%u\n", field_get(mask, ret)); + } + + return -EINVAL; +} + +static ssize_t rs5600_attr_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t len) +{ + struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev)); + struct as5600_priv *priv = iio_priv(indio_dev); + struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); + unsigned int reg = reg_from_address(this_attr->address); + unsigned int mask = mask_from_address(this_attr->address); + u16 val_in; + u16 out; + int ret; + + ret = kstrtou16(buf, 0, &val_in); + if (ret) + return ret; + + switch (reg) { + case REG_ZPOS: + case REG_MPOS: + case REG_CONF: + /* Read then write, as per spec */ + ret = i2c_smbus_read_word_swapped(priv->client, reg); + if (ret < 0) + return ret; + + out = ret & ~mask; + out |= field_prep(mask, val_in); + + ret = i2c_smbus_write_word_swapped(priv->client, reg, out); + if (ret < 0) + return ret; + break; + } + + return len; +} + +#define AS5600_ATTR_RO(name, reg, field) \ + IIO_DEVICE_ATTR(name, 0444, rs5600_attr_show, NULL, to_address(reg, field)) + +#define AS5600_ATTR_RW(name, reg, field) \ + IIO_DEVICE_ATTR(name, 0644, rs5600_attr_show, rs5600_attr_store, \ + to_address(reg, field)) + +static AS5600_ATTR_RO(zmco, ZMCO, ZMCO); +static AS5600_ATTR_RO(conf_pm, CONF, PM); +static AS5600_ATTR_RO(conf_hyst, CONF, HYST); +static AS5600_ATTR_RO(conf_outs, CONF, OUTS); +static AS5600_ATTR_RO(conf_pwmf, CONF, PWMF); +static AS5600_ATTR_RO(conf_sf, CONF, SF); +static AS5600_ATTR_RO(conf_fth, CONF, FTH); +static AS5600_ATTR_RO(conf_wd, CONF, WD); +static AS5600_ATTR_RO(mang, MANG, MANG); +static AS5600_ATTR_RO(status_mh, STATUS, MH); +static AS5600_ATTR_RO(status_ml, STATUS, ML); +static AS5600_ATTR_RO(status_md, STATUS, MD); +static AS5600_ATTR_RO(agc, AGC, AGC); +static AS5600_ATTR_RO(magnitude, MAGNITUDE, MAGNITUDE); + +static AS5600_ATTR_RW(zpos, ZPOS, ZPOS); +static AS5600_ATTR_RW(mpos, MPOS, MPOS); + +static struct attribute *as5600_attributes[] = { + &iio_dev_attr_zmco.dev_attr.attr, + &iio_dev_attr_zpos.dev_attr.attr, + &iio_dev_attr_mpos.dev_attr.attr, + &iio_dev_attr_mang.dev_attr.attr, + &iio_dev_attr_conf_pm.dev_attr.attr, + &iio_dev_attr_conf_hyst.dev_attr.attr, + &iio_dev_attr_conf_outs.dev_attr.attr, + &iio_dev_attr_conf_pwmf.dev_attr.attr, + &iio_dev_attr_conf_sf.dev_attr.attr, + &iio_dev_attr_conf_fth.dev_attr.attr, + &iio_dev_attr_conf_wd.dev_attr.attr, + &iio_dev_attr_status_mh.dev_attr.attr, + &iio_dev_attr_status_ml.dev_attr.attr, + &iio_dev_attr_status_md.dev_attr.attr, + &iio_dev_attr_agc.dev_attr.attr, + &iio_dev_attr_magnitude.dev_attr.attr, + NULL +}; + +static const struct attribute_group as5600_attr_group = { + .attrs = as5600_attributes, +}; + +static const struct iio_chan_spec as5600_channels[] = { + { + .type = IIO_ANGL, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), + .indexed = 1, + .channel = 0, + .address = to_address(RAW_ANGLE, ANGLE), + }, + { + .type = IIO_ANGL, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), + .indexed = 1, + .channel = 1, + .address = to_address(ANGLE, ANGLE), + }, +}; + +static const struct iio_info as5600_info = { + .read_raw = &as5600_read_raw, + .attrs = &as5600_attr_group, +}; + +static int as5600_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct as5600_priv *priv; + struct iio_dev *indio_dev; + int ret; + + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*priv)); + if (!indio_dev) + return -ENOMEM; + + priv = iio_priv(indio_dev); + i2c_set_clientdata(client, indio_dev); + priv->client = client; + + indio_dev->info = &as5600_info; + indio_dev->name = "as5600"; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = as5600_channels; + indio_dev->num_channels = ARRAY_SIZE(as5600_channels); + + ret = i2c_smbus_read_byte_data(client, REG_STATUS); + if (ret < 0) + return ret; + + /* No magnet present could be a problem. */ + if ((ret & REG_STATUS_MD) == 0) + dev_warn(&client->dev, "Magnet not detected\n"); + + return devm_iio_device_register(&client->dev, indio_dev); +} + +static const struct i2c_device_id as5600_i2c_id[] = { + {"as5600", 0}, + {} +}; +MODULE_DEVICE_TABLE(i2c, as5600_i2c_id); + +static struct i2c_driver as5600_driver = { + .driver = { + .name = "as5600_i2c", + }, + .probe = as5600_probe, + .id_table = as5600_i2c_id, +}; + +module_i2c_driver(as5600_driver); + +MODULE_AUTHOR("Frank Zago <frank@xxxxxxxx>"); +MODULE_DESCRIPTION("ams AS5600 Contactless Potentiometer"); +MODULE_LICENSE("GPL"); -- 2.32.0
