FXAS21002C is a 3 axis gyroscope with integrated temperature sensor Signed-off-by: Afonso Bordado <afonsobordado@xxxxxx> --- Changes in v2 - Use ANSI C Comments - Minor cleanups - More dscriptive devicetree bindings drivers/iio/gyro/Kconfig | 11 + drivers/iio/gyro/Makefile | 1 + drivers/iio/gyro/fxas21002c.c | 367 ++++++++++++++++++++++++++++++++++ 3 files changed, 379 insertions(+) create mode 100644 drivers/iio/gyro/fxas21002c.c diff --git a/drivers/iio/gyro/Kconfig b/drivers/iio/gyro/Kconfig index 3126cf05e6b9..d71e33ea9fa4 100644 --- a/drivers/iio/gyro/Kconfig +++ b/drivers/iio/gyro/Kconfig @@ -73,6 +73,17 @@ config BMG160_SPI tristate select REGMAP_SPI +config FXAS21002C + tristate "Freescale FXAS21002C Gyroscope" + depends on I2C + select REGMAP_I2C + help + Say yes here to build support for the Freescale FXAS21002C Gyroscope + driver connected via I2C. + + This driver can also be built as a module. If so, the module + will be called fxas21002c. + config HID_SENSOR_GYRO_3D depends on HID_SENSOR_HUB select IIO_BUFFER diff --git a/drivers/iio/gyro/Makefile b/drivers/iio/gyro/Makefile index 295ec780c4eb..ec3e2aeae92a 100644 --- a/drivers/iio/gyro/Makefile +++ b/drivers/iio/gyro/Makefile @@ -12,6 +12,7 @@ obj-$(CONFIG_ADXRS450) += adxrs450.o obj-$(CONFIG_BMG160) += bmg160_core.o obj-$(CONFIG_BMG160_I2C) += bmg160_i2c.o obj-$(CONFIG_BMG160_SPI) += bmg160_spi.o +obj-$(CONFIG_FXAS21002C) += fxas21002c.o obj-$(CONFIG_HID_SENSOR_GYRO_3D) += hid-sensor-gyro-3d.o diff --git a/drivers/iio/gyro/fxas21002c.c b/drivers/iio/gyro/fxas21002c.c new file mode 100644 index 000000000000..261b73629544 --- /dev/null +++ b/drivers/iio/gyro/fxas21002c.c @@ -0,0 +1,367 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * FXAS21002C - Digital Angular Rate Gyroscope driver + * + * Copyright (c) 2018, Afonso Bordado <afonsobordado@xxxxxx> + * + * IIO driver for FXAS21002C (7-bit I2C slave address 0x20 or 0x21). + * Datasheet: https://www.nxp.com/docs/en/data-sheet/FXAS21002.pdf + * TODO: + * ODR / Scale Support + * Devicetree + * Power management + * LowPass/HighPass Filters + * Buffers + * Interrupts + * Alarms + */ + +#include <linux/module.h> +#include <linux/i2c.h> +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> +#include <linux/regmap.h> + +#define FXAS21002C_DRV_NAME "fxas21002c" + +#define FXAS21002C_MAX_TRANSITION_TIME_MS 61 + +#define FXAS21002C_CHIP_ID 0xD7 + +#define FXAS21002C_REG_STATUS 0x00 +#define FXAS21002C_REG_OUT_X_MSB 0x01 +#define FXAS21002C_REG_OUT_X_LSB 0x02 +#define FXAS21002C_REG_OUT_Y_MSB 0x03 +#define FXAS21002C_REG_OUT_Y_LSB 0x04 +#define FXAS21002C_REG_OUT_Z_MSB 0x05 +#define FXAS21002C_REG_OUT_Z_LSB 0x06 +#define FXAS21002C_REG_DR_STATUS 0x07 +#define FXAS21002C_REG_F_STATUS 0x08 +#define FXAS21002C_REG_F_SETUP 0x09 +#define FXAS21002C_REG_F_EVENT 0x0A +#define FXAS21002C_REG_INT_SRC_FLAG 0x0B +#define FXAS21002C_REG_WHO_AM_I 0x0C +#define FXAS21002C_REG_CTRL_REG0 0x0D +#define FXAS21002C_REG_RT_CFG 0x0E +#define FXAS21002C_REG_RT_SRC 0x0F +#define FXAS21002C_REG_RT_THS 0x10 +#define FXAS21002C_REG_RT_COUNT 0x11 +#define FXAS21002C_REG_TEMP 0x12 + +#define FXAS21002C_REG_CTRL_REG1 0x13 +#define FXAS21002C_RST_BIT BIT(6) +#define FXAS21002C_ACTIVE_BIT BIT(1) +#define FXAS21002C_READY_BIT BIT(0) + +#define FXAS21002C_REG_CTRL_REG2 0x14 +#define FXAS21002C_REG_CTRL_REG3 0x15 + +#define FXAS21002C_DEFAULT_ODR_HZ 800 + +/* 0.0625 deg/s */ +#define FXAS21002C_DEFAULT_SENSITIVITY IIO_DEGREE_TO_RAD(62500) + +#define FXAS21002C_TEMP_SCALE 1000 + +enum fxas21002c_id { + ID_FXAS21002C, +}; + +enum fxas21002c_operating_mode { + FXAS21002C_OM_BOOT, + FXAS21002C_OM_STANDBY, + FXAS21002C_OM_READY, + FXAS21002C_OM_ACTIVE, +}; + +struct fxas21002c_data { + struct i2c_client *client; + struct regmap *regmap; +}; + +static const struct regmap_range fxas21002c_writable_ranges[] = { + regmap_reg_range(FXAS21002C_REG_F_SETUP, FXAS21002C_REG_F_SETUP), + regmap_reg_range(FXAS21002C_REG_CTRL_REG0, FXAS21002C_REG_RT_CFG), + regmap_reg_range(FXAS21002C_REG_RT_THS, FXAS21002C_REG_RT_COUNT), + regmap_reg_range(FXAS21002C_REG_CTRL_REG1, FXAS21002C_REG_CTRL_REG3), +}; + +static const struct regmap_access_table fxas21002c_writable_table = { + .yes_ranges = fxas21002c_writable_ranges, + .n_yes_ranges = ARRAY_SIZE(fxas21002c_writable_ranges), +}; + +static const struct regmap_range fxas21002c_volatile_ranges[] = { + regmap_reg_range(FXAS21002C_REG_STATUS, FXAS21002C_REG_F_STATUS), + regmap_reg_range(FXAS21002C_REG_F_EVENT, FXAS21002C_REG_INT_SRC_FLAG), + regmap_reg_range(FXAS21002C_REG_RT_COUNT, FXAS21002C_REG_CTRL_REG1), +}; + +static const struct regmap_access_table fxas21002c_volatile_table = { + .yes_ranges = fxas21002c_volatile_ranges, + .n_yes_ranges = ARRAY_SIZE(fxas21002c_volatile_ranges), +}; + +const struct regmap_config fxas21002c_regmap_config = { + .reg_bits = 8, + .val_bits = 8, + + .max_register = FXAS21002C_REG_CTRL_REG3, + /* We don't specify a .rd_table because everything is readable */ + .wr_table = &fxas21002c_writable_table, + .volatile_table = &fxas21002c_volatile_table, +}; +EXPORT_SYMBOL(fxas21002c_regmap_config); + +#define FXAS21002C_GYRO_CHAN(_axis) { \ + .type = IIO_ANGL_VEL, \ + .modified = 1, \ + .channel2 = IIO_MOD_ ## _axis, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \ + BIT(IIO_CHAN_INFO_SAMP_FREQ), \ + .address = FXAS21002C_REG_OUT_ ## _axis ## _MSB, \ +} + +static const struct iio_chan_spec fxas21002c_channels[] = { + { + .type = IIO_TEMP, + .address = FXAS21002C_REG_TEMP, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), + }, + FXAS21002C_GYRO_CHAN(X), + FXAS21002C_GYRO_CHAN(Y), + FXAS21002C_GYRO_CHAN(Z), + IIO_CHAN_SOFT_TIMESTAMP(3), +}; + +static int fxas21002c_set_operating_mode(struct fxas21002c_data *data, + enum fxas21002c_operating_mode om) +{ + int ret; + int mask; + + switch (om) { + case FXAS21002C_OM_STANDBY: + mask = 0; + break; + case FXAS21002C_OM_READY: + mask = FXAS21002C_READY_BIT; + break; + case FXAS21002C_OM_ACTIVE: + mask = FXAS21002C_ACTIVE_BIT; + break; + + default: + return -EINVAL; + } + + ret = regmap_write(data->regmap, FXAS21002C_REG_CTRL_REG1, mask); + if (ret) { + dev_err(&data->client->dev, + "could not switch operating mode\n"); + return ret; + } + + msleep(FXAS21002C_MAX_TRANSITION_TIME_MS); + + return 0; +} + +static void fxas21002c_standby(void *_data) +{ + struct fxas21002c_data *data = _data; + + fxas21002c_set_operating_mode(data, FXAS21002C_OM_STANDBY); +} + +static int fxas21002c_reset(struct fxas21002c_data *data) +{ + int ret; + + /* + * On issuing a Software Reset command over an I2C interface, + * the device immediately resets and does not send any + * acknowledgment (ACK) of the written byte to the Master. + * + * This is documented in table 46 on the datasheet. Due to this + * the write will fail with EREMOTEIO. + */ + ret = regmap_write(data->regmap, + FXAS21002C_REG_CTRL_REG1, FXAS21002C_RST_BIT); + + if (ret != -EREMOTEIO) { + dev_err(&data->client->dev, "could not reset device\n"); + return ret; + } + + regcache_mark_dirty(data->regmap); + + /* Wait for device to boot up */ + msleep(FXAS21002C_MAX_TRANSITION_TIME_MS); + + return 0; +} + +static int fxas21002c_verify_chip(struct fxas21002c_data *data) +{ + int ret; + int chip_id; + + ret = regmap_read(data->regmap, FXAS21002C_REG_WHO_AM_I, &chip_id); + if (ret) { + dev_err(&data->client->dev, "could not read device id\n"); + return ret; + } + + if (chip_id != FXAS21002C_CHIP_ID) { + dev_err(&data->client->dev, + "unsupported chip id %02x\n", chip_id); + return -ENODEV; + } + + return 0; +} + +static int fxas21002c_read_oneshot(struct fxas21002c_data *data, + struct iio_chan_spec const *chan, int *val) +{ + int ret; + __be16 bulk_raw; + + switch (chan->type) { + case IIO_ANGL_VEL: + ret = regmap_bulk_read(data->regmap, chan->address, + &bulk_raw, sizeof(bulk_raw)); + if (ret) + return ret; + + *val = sign_extend32(be16_to_cpu(bulk_raw), 15); + return IIO_VAL_INT; + case IIO_TEMP: + ret = regmap_read(data->regmap, chan->address, val); + if (ret) + return ret; + + return IIO_VAL_INT; + default: + return -EINVAL; + } +} + +static int fxas21002c_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int *val, + int *val2, long mask) +{ + struct fxas21002c_data *data = iio_priv(indio_dev); + + switch (mask) { + case IIO_CHAN_INFO_RAW: + return fxas21002c_read_oneshot(data, chan, val); + case IIO_CHAN_INFO_SCALE: + switch (chan->type) { + case IIO_ANGL_VEL: + *val = 0; + *val2 = FXAS21002C_DEFAULT_SENSITIVITY; + + return IIO_VAL_INT_PLUS_MICRO; + case IIO_TEMP: + *val = FXAS21002C_TEMP_SCALE; + + return IIO_VAL_INT; + default: + return -EINVAL; + } + case IIO_CHAN_INFO_SAMP_FREQ: + if (chan->type != IIO_ANGL_VEL) + return -EINVAL; + + *val = FXAS21002C_DEFAULT_ODR_HZ; + + return IIO_VAL_INT; + } + + return -EINVAL; +} + +static const struct iio_info fxas21002c_info = { + .read_raw = fxas21002c_read_raw, +}; + +static int fxas21002c_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + int ret; + struct iio_dev *indio_dev; + struct fxas21002c_data *data; + + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); + if (!indio_dev) + return -ENOMEM; + + i2c_set_clientdata(client, indio_dev); + data = iio_priv(indio_dev); + data->client = client; + + data->regmap = devm_regmap_init_i2c(client, &fxas21002c_regmap_config); + if (IS_ERR(data->regmap)) { + ret = PTR_ERR(data->regmap); + dev_err(&client->dev, + "Failed to allocate regmap, err: %d\n", ret); + return ret; + } + + indio_dev->dev.parent = &client->dev; + indio_dev->channels = fxas21002c_channels; + indio_dev->num_channels = ARRAY_SIZE(fxas21002c_channels); + indio_dev->name = id->name; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->info = &fxas21002c_info; + + ret = fxas21002c_verify_chip(data); + if (ret < 0) + return ret; + + ret = fxas21002c_reset(data); + if (ret < 0) + return ret; + + ret = fxas21002c_set_operating_mode(data, FXAS21002C_OM_ACTIVE); + if (ret < 0) + return ret; + + ret = devm_add_action(&client->dev, fxas21002c_standby, data); + if (ret < 0) { + fxas21002c_standby(data); + dev_err(&client->dev, "failed to add standby action\n"); + return ret; + } + + ret = iio_device_register(indio_dev); + if (ret < 0) + dev_err(&client->dev, "failed to register iio device\n"); + + return ret; +} + +static const struct i2c_device_id fxas21002c_id[] = { + {"fxas21002c", ID_FXAS21002C}, + {} +}; + +MODULE_DEVICE_TABLE(i2c, fxas21002c_id); + +static struct i2c_driver fxas21002c_driver = { + .driver = { + .name = FXAS21002C_DRV_NAME, + }, + .probe = fxas21002c_probe, + .id_table = fxas21002c_id, +}; + +module_i2c_driver(fxas21002c_driver); + +MODULE_AUTHOR("Afonso Bordado <afonsobordado@xxxxxx>"); +MODULE_DESCRIPTION("FXAS21002C Digital Angular Rate Gyroscope driver"); +MODULE_LICENSE("GPL v2"); -- 2.18.0
