The DPS310 is a temperature and pressure sensor. It can be accessed over i2c and SPI.
This driver supports polled measurement of temperature over i2c only. Signed-off-by: Joel Stanley <[email protected]> --- drivers/iio/pressure/Kconfig | 11 ++ drivers/iio/pressure/Makefile | 1 + drivers/iio/pressure/dps310.c | 401 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 413 insertions(+) create mode 100644 drivers/iio/pressure/dps310.c diff --git a/drivers/iio/pressure/Kconfig b/drivers/iio/pressure/Kconfig index bd8d96b96771..50caefc0cd7d 100644 --- a/drivers/iio/pressure/Kconfig +++ b/drivers/iio/pressure/Kconfig @@ -42,6 +42,17 @@ config BMP280_SPI depends on SPI_MASTER select REGMAP +config DPS310 + tristate "Infineon DPS310 pressure and temperature sensor" + depends on I2C + select REGMAP_I2C + help + Support for the Infineon DPS310 digital barometric pressure sensor. + This driver measures temperature only. + + This driver can also be built as a module. If so, the module will be + called dps310. + config HID_SENSOR_PRESS depends on HID_SENSOR_HUB select IIO_BUFFER diff --git a/drivers/iio/pressure/Makefile b/drivers/iio/pressure/Makefile index de3dbc81dc5a..997bbaebfa34 100644 --- a/drivers/iio/pressure/Makefile +++ b/drivers/iio/pressure/Makefile @@ -8,6 +8,7 @@ obj-$(CONFIG_BMP280) += bmp280.o bmp280-objs := bmp280-core.o bmp280-regmap.o obj-$(CONFIG_BMP280_I2C) += bmp280-i2c.o obj-$(CONFIG_BMP280_SPI) += bmp280-spi.o +obj-$(CONFIG_DPS310) += dps310.o obj-$(CONFIG_HID_SENSOR_PRESS) += hid-sensor-press.o obj-$(CONFIG_HP03) += hp03.o obj-$(CONFIG_MPL115) += mpl115.o diff --git a/drivers/iio/pressure/dps310.c b/drivers/iio/pressure/dps310.c new file mode 100644 index 000000000000..5e8f91a5662b --- /dev/null +++ b/drivers/iio/pressure/dps310.c @@ -0,0 +1,401 @@ +/* + * Copyright 2017 IBM Corporation + * + * Joel Stanley <[email protected]> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * The DPS310 is a barometric pressure and temperature sensor. + * Currently only reading a single temperature is supported by + * this driver. + * + * TODO: + * - Pressure sensor readings + * - Optionally support the FIFO + */ + +#include <linux/module.h> +#include <linux/i2c.h> +#include <linux/regmap.h> +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> + +#define PRS_BASE 0x00 +#define TMP_BASE 0x03 +#define PRS_CFG 0x06 +#define TMP_CFG 0x07 +#define TMP_RATE_BITS GENMASK(6, 4) +#define TMP_PRC_BITS GENMASK(3, 0) +#define TMP_EXT BIT(7) +#define MEAS_CFG 0x08 +#define MEAS_CTRL_BITS GENMASK(2, 0) +#define PRESSURE_EN BIT(0) +#define TEMP_EN BIT(1) +#define BACKGROUND BIT(2) +#define PRS_RDY BIT(4) +#define TMP_RDY BIT(5) +#define SENSOR_RDY BIT(6) +#define COEF_RDY BIT(7) +#define CFG_REG 0x09 +#define INT_HL BIT(7) +#define TMP_SHIFT_EN BIT(3) +#define PRS_SHIFT_EN BIT(4) +#define FIFO_EN BIT(5) +#define SPI_EN BIT(6) +#define RESET 0x0c +#define RESET_MAGIC (BIT(0) | BIT(3)) +#define COEF_BASE 0x10 + +#define TMP_RATE(_n) ilog2(_n) +#define TMP_PRC(_n) ilog2(_n) + +#define MCELSIUS_PER_CELSIUS 1000 + +const int scale_factor[] = { + 524288, + 1572864, + 3670016, + 7864320, + 253952, + 516096, + 1040384, + 2088960, +}; + +struct dps310_data { + struct i2c_client *client; + struct regmap *regmap; + + s32 c0, c1; + s32 temp_raw; +}; + +static const struct iio_chan_spec dps310_channels[] = { + { + .type = IIO_TEMP, + .info_mask_separate = BIT(IIO_CHAN_INFO_OFFSET) | + BIT(IIO_CHAN_INFO_SCALE) | + BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO) | + BIT(IIO_CHAN_INFO_SAMP_FREQ) | + BIT(IIO_CHAN_INFO_RAW), + }, +}; + +static s32 dps310_twos_compliment(u32 raw, size_t num_bits) +{ + s32 out = raw; + + if (raw & BIT(num_bits - 1)) + out = raw - BIT(num_bits); + + return out; +} + +static int dps310_get_temp_coef(struct dps310_data *data) +{ + struct regmap *regmap = data->regmap; + uint8_t coef[3] = {0}; + int ready, r; + u32 c0, c1; + + r = regmap_read(regmap, MEAS_CFG, &ready); + if (r < 0) + return r; + + if (!(ready & COEF_RDY)) + return -EAGAIN; + + /* + * Read temperature calibration coefficients c0 and c1 from the + * COEF register. The numbers are 12-bit 2's compliment numbers + */ + r = regmap_bulk_read(regmap, COEF_BASE, coef, 3); + if (r < 0) + return r; + + c0 = (coef[0] << 4) | (coef[1] >> 4); + data->c0 = dps310_twos_compliment(c0, 12); + + c1 = ((coef[1] & GENMASK(3, 0)) << 8) | coef[2]; + data->c1 = dps310_twos_compliment(c1, 12); + + return 0; +} + +static int dps310_get_temp_precision(struct dps310_data *data) +{ + int val, r; + + r = regmap_read(data->regmap, TMP_CFG, &val); + if (r < 0) + return r; + + /* + * Scale factor is bottom 4 bits of the register, but 1111 is + * reserved so just grab bottom three + */ + return BIT(val & GENMASK(2, 0)); +} + +static int dps310_set_temp_precision(struct dps310_data *data, int val) +{ + int ret; + u8 shift_en; + + if (val < 0 || val > 128) + return -EINVAL; + + shift_en = val >= 16 ? TMP_SHIFT_EN : 0; + ret = regmap_write_bits(data->regmap, CFG_REG, TMP_SHIFT_EN, shift_en); + if (ret) + return ret; + + return regmap_update_bits(data->regmap, TMP_CFG, TMP_PRC_BITS, + TMP_PRC(val)); +} + +static int dps310_set_temp_samp_freq(struct dps310_data *data, int freq) +{ + uint8_t val; + + if (freq < 0 || freq > 128) + return -EINVAL; + + val = ilog2(freq) << 4; + + return regmap_update_bits(data->regmap, TMP_CFG, TMP_RATE_BITS, val); +} + +static int dps310_get_temp_samp_freq(struct dps310_data *data) +{ + int val, r; + + r = regmap_read(data->regmap, TMP_CFG, &val); + if (r < 0) + return r; + + return BIT((val & TMP_RATE_BITS) >> 4); +} + +static int dps310_get_temp_k(struct dps310_data *data) +{ + int index = ilog2(dps310_get_temp_precision(data)); + + return scale_factor[index]; +} + +static int dps310_read_temp(struct dps310_data *data) +{ + struct device *dev = &data->client->dev; + struct regmap *regmap = data->regmap; + uint8_t val[3] = {0}; + int r, ready; + int T_raw; + + r = regmap_read(regmap, MEAS_CFG, &ready); + if (r < 0) + return r; + if (!(ready & TMP_RDY)) { + dev_dbg(dev, "temperature not ready\n"); + return -EAGAIN; + } + + r = regmap_bulk_read(regmap, TMP_BASE, val, 3); + if (r < 0) + return r; + + T_raw = (val[0] << 16) | (val[1] << 8) | val[2]; + data->temp_raw = dps310_twos_compliment(T_raw, 24); + + return 0; +} + +static bool dps310_is_writeable_reg(struct device *dev, unsigned int reg) +{ + switch (reg) { + case PRS_CFG: + case TMP_CFG: + case MEAS_CFG: + case CFG_REG: + case RESET: + return true; + default: + return false; + } +} + +static bool dps310_is_volatile_reg(struct device *dev, unsigned int reg) +{ + switch (reg) { + case PRS_BASE ... (PRS_BASE + 2): + case TMP_BASE ... (TMP_BASE + 2): + case MEAS_CFG: + return true; + default: + return false; + } +} + +static int dps310_write_raw(struct iio_dev *iio, + struct iio_chan_spec const *chan, int val, + int val2, long mask) +{ + struct dps310_data *data = iio_priv(iio); + + if (chan->type != IIO_TEMP) + return -EINVAL; + + switch (mask) { + case IIO_CHAN_INFO_SAMP_FREQ: + return dps310_set_temp_samp_freq(data, val); + case IIO_CHAN_INFO_OVERSAMPLING_RATIO: + return dps310_set_temp_precision(data, val); + default: + return -EINVAL; + } + + return -EINVAL; +} + +static int dps310_read_raw(struct iio_dev *iio, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct dps310_data *data = iio_priv(iio); + int ret; + + /* c0 * 0.5 + c1 * T_raw / kT °C */ + switch (mask) { + case IIO_CHAN_INFO_SAMP_FREQ: + *val = dps310_get_temp_samp_freq(data); + return IIO_VAL_INT; + + case IIO_CHAN_INFO_RAW: + ret = dps310_read_temp(data); + if (ret) + return ret; + + *val = data->temp_raw * data->c1; + return IIO_VAL_INT; + + case IIO_CHAN_INFO_OFFSET: + *val = (data->c0 >> 1) * dps310_get_temp_k(data); + return IIO_VAL_INT; + + case IIO_CHAN_INFO_SCALE: + *val = MCELSIUS_PER_CELSIUS; + *val2 = dps310_get_temp_k(data); + return IIO_VAL_FRACTIONAL; + + case IIO_CHAN_INFO_OVERSAMPLING_RATIO: + *val = dps310_get_temp_precision(data); + return IIO_VAL_INT; + + default: + return -EINVAL; + } + + return -EINVAL; +} + +static const struct regmap_config dps310_regmap_config = { + .reg_bits = 8, + .val_bits = 8, + .writeable_reg = dps310_is_writeable_reg, + .volatile_reg = dps310_is_volatile_reg, + .cache_type = REGCACHE_RBTREE, + .max_register = 0x29, +}; + +static const struct iio_info dps310_info = { + .driver_module = THIS_MODULE, + .read_raw = dps310_read_raw, + .write_raw = dps310_write_raw, +}; + +static int dps310_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct dps310_data *data; + struct iio_dev *iio; + int r; + + iio = devm_iio_device_alloc(&client->dev, sizeof(*data)); + if (!iio) + return -ENOMEM; + + data = iio_priv(iio); + data->client = client; + + iio->dev.parent = &client->dev; + iio->name = id->name; + iio->channels = dps310_channels; + iio->num_channels = ARRAY_SIZE(dps310_channels); + iio->info = &dps310_info; + iio->modes = INDIO_DIRECT_MODE; + + data->regmap = devm_regmap_init_i2c(client, &dps310_regmap_config); + if (IS_ERR(data->regmap)) + return PTR_ERR(data->regmap); + + r = regmap_write(data->regmap, TMP_CFG, TMP_EXT | TMP_PRC(1)); + if (r < 0) + return r; + r = regmap_write_bits(data->regmap, CFG_REG, TMP_SHIFT_EN, 0); + if (r < 0) + return r; + + /* Turn on temperature measurement in the background */ + r = regmap_write_bits(data->regmap, MEAS_CFG, MEAS_CTRL_BITS, + TEMP_EN | BACKGROUND); + if (r < 0) + return r; + + /* + * Calibration coefficients required for reporting temperature. + * They are availalbe 40ms after the device has started + */ + r = dps310_get_temp_coef(data); + if (r == -EAGAIN) + return -EPROBE_DEFER; + if (r < 0) + return r; + + r = devm_iio_device_register(&client->dev, iio); + if (r) + return r; + + i2c_set_clientdata(client, iio); + + dev_info(&client->dev, "%s: sensor '%s'\n", dev_name(&iio->dev), + client->name); + + return 0; +} + +static const struct i2c_device_id dps310_id[] = { + { "dps310", 0 }, + {} +}; +MODULE_DEVICE_TABLE(i2c, dps310_id); + +static const unsigned short normal_i2c[] = { + 0x77, 0x76, I2C_CLIENT_END +}; + +static struct i2c_driver dps310_driver = { + .driver = { + .name = "dps310", + }, + .probe = dps310_probe, + .address_list = normal_i2c, + .id_table = dps310_id, +}; +module_i2c_driver(dps310_driver); + +MODULE_AUTHOR("Joel Stanley <[email protected]>"); +MODULE_DESCRIPTION("Infineon DPS310 pressure and temperature sensor"); +MODULE_LICENSE("GPL"); -- 2.11.0
