On Mon, 6 May 2019, Eddie James wrote: > From: Joel Stanley <j...@jms.id.au>
some comments below > The DPS310 is a temperature and pressure sensor. It can be accessed over > i2c and SPI. > > Signed-off-by: Eddie James <eaja...@linux.ibm.com> > --- > MAINTAINERS | 6 + > drivers/iio/pressure/Kconfig | 10 + > drivers/iio/pressure/Makefile | 1 + > drivers/iio/pressure/dps310.c | 429 > ++++++++++++++++++++++++++++++++++++++++++ > 4 files changed, 446 insertions(+) > create mode 100644 drivers/iio/pressure/dps310.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index c61c49d..a91dfa9 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -7743,6 +7743,12 @@ W: http://industrypack.sourceforge.net > S: Maintained > F: drivers/ipack/ > > +INFINEON DPS310 Driver > +M: Eddie James <eaja...@linux.ibm.com> > +L: linux-...@vger.kernel.org > +F: drivers/iio/pressure/dps310.c > +S: Maintained > + > INFINIBAND SUBSYSTEM > M: Doug Ledford <dledf...@redhat.com> > M: Jason Gunthorpe <j...@mellanox.com> > diff --git a/drivers/iio/pressure/Kconfig b/drivers/iio/pressure/Kconfig > index efeb89f..681a1cc 100644 > --- a/drivers/iio/pressure/Kconfig > +++ b/drivers/iio/pressure/Kconfig > @@ -52,6 +52,16 @@ config IIO_CROS_EC_BARO > To compile this driver as a module, choose M here: the module > will be called cros_ec_baro. > > +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 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 c2058d7..d8f5ace 100644 > --- a/drivers/iio/pressure/Makefile > +++ b/drivers/iio/pressure/Makefile > @@ -9,6 +9,7 @@ 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-$(CONFIG_IIO_CROS_EC_BARO) += cros_ec_baro.o > obj-$(CONFIG_HID_SENSOR_PRESS) += hid-sensor-press.o > obj-$(CONFIG_HP03) += hp03.o > diff --git a/drivers/iio/pressure/dps310.c b/drivers/iio/pressure/dps310.c > new file mode 100644 > index 0000000..21d5dcb > --- /dev/null > +++ b/drivers/iio/pressure/dps310.c > @@ -0,0 +1,429 @@ > +// SPDX-License-Identifier: GPL-2.0+ > +// Copyright IBM Corp 2019 > +/* > + * The DPS310 is a barometric pressure and temperature sensor. > + * Currently only reading a single temperature is supported by > + * this driver. > + * > + * https://www.infineon.com/dgdl/?fileId=5546d462576f34750157750826c42242 > + * > + * Temperature calculation: > + * c0 * 0.5 + c1 * T_raw / kT °C > + * > + * TODO: > + * - Pressure sensor readings > + * - Optionally support the FIFO > + */ > + > +#include <linux/i2c.h> > +#include <linux/module.h> > +#include <linux/regmap.h> > + > +#include <linux/iio/iio.h> > +#include <linux/iio/sysfs.h> > + > +#define DPS310_PRS_B0 0x00 > +#define DPS310_PRS_B1 0x01 > +#define DPS310_PRS_B2 0x02 > +#define DPS310_TMP_B0 0x03 > +#define DPS310_TMP_B1 0x04 > +#define DPS310_TMP_B2 0x05 > +#define DPS310_PRS_CFG 0x06 > +#define DPS310_TMP_CFG 0x07 > +#define DPS310_TMP_RATE_BITS GENMASK(6, 4) > +#define DPS310_TMP_PRC_BITS GENMASK(3, 0) > +#define DPS310_TMP_EXT BIT(7) > +#define DPS310_MEAS_CFG 0x08 > +#define DPS310_MEAS_CTRL_BITS GENMASK(2, 0) > +#define DPS310_PRS_EN BIT(0) > +#define DPS310_TEMP_EN BIT(1) > +#define DPS310_BACKGROUND BIT(2) > +#define DPS310_PRS_RDY BIT(4) > +#define DPS310_TMP_RDY BIT(5) > +#define DPS310_SENSOR_RDY BIT(6) > +#define DPS310_COEF_RDY BIT(7) > +#define DPS310_CFG_REG 0x09 > +#define DPS310_INT_HL BIT(7) > +#define DPS310_TMP_SHIFT_EN BIT(3) > +#define DPS310_PRS_SHIFT_EN BIT(4) > +#define DPS310_FIFO_EN BIT(5) > +#define DPS310_SPI_EN BIT(6) > +#define DPS310_RESET 0x0c > +#define DPS310_RESET_MAGIC (BIT(0) | BIT(3)) > +#define DPS310_COEF_BASE 0x10 > + > +#define DPS310_PRS_BASE DPS310_PRS_B0 > +#define DPS310_TMP_BASE DPS310_TMP_B0 > + > +#define DPS310_CALC_RATE(_n) ilog2(_n) > +#define DPS310_CALC_PRC(_n) ilog2(_n) > + > +const int scale_factor[] = { static maybe plural, scale_factors? maybe some comment would be good what these values relate to > + 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), > + }, > +}; > + > +/* To be called after checking the TMP_RDY bit in MEAS_CFG */ > +static int dps310_get_temp_coef(struct dps310_data *data) > +{ > + struct regmap *regmap = data->regmap; > + u8 coef[3] = {0}; initialization needed? > + int r; > + u32 c0, c1; > + > + /* > + * 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, DPS310_COEF_BASE, coef, 3); sizeof(coef) instead of 3 > + if (r < 0) > + return r; > + > + c0 = (coef[0] << 4) | (coef[1] >> 4); > + data->c0 = sign_extend32(c0, 11); > + > + c1 = ((coef[1] & GENMASK(3, 0)) << 8) | coef[2]; > + data->c1 = sign_extend32(c1, 11); > + > + return 0; > +} > + > +static int dps310_get_temp_precision(struct dps310_data *data) > +{ > + int val, r; > + > + r = regmap_read(data->regmap, DPS310_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 ? DPS310_TMP_SHIFT_EN : 0; > + ret = regmap_write_bits(data->regmap, DPS310_CFG_REG, > + DPS310_TMP_SHIFT_EN, shift_en); > + if (ret) > + return ret; > + > + return regmap_update_bits(data->regmap, DPS310_TMP_CFG, > + DPS310_TMP_PRC_BITS, DPS310_CALC_PRC(val)); > +} > + > +static int dps310_set_temp_samp_freq(struct dps310_data *data, int freq) > +{ > + u8 val; > + > + if (freq < 0 || freq > 128) > + return -EINVAL; > + > + val = DPS310_CALC_RATE(freq) << 4; > + > + return regmap_update_bits(data->regmap, DPS310_TMP_CFG, > + DPS310_TMP_RATE_BITS, val); > +} > + > +static int dps310_get_temp_samp_freq(struct dps310_data *data) > +{ > + int val, r; > + > + r = regmap_read(data->regmap, DPS310_TMP_CFG, &val); > + if (r < 0) > + return r; > + > + return BIT((val & DPS310_TMP_RATE_BITS) >> 4); > +} > + > +static int dps310_get_temp_k(struct dps310_data *data) > +{ > + int r = dps310_get_temp_precision(data); > + > + if (r < 0) > + return r; > + > + return scale_factor[DPS310_CALC_PRC(r)]; > +} > + > +static int dps310_read_temp(struct dps310_data *data) > +{ > + struct device *dev = &data->client->dev; > + struct regmap *regmap = data->regmap; > + u8 val[3] = {0}; initialization needed? > + int r, ready; > + int T_raw; > + > + r = regmap_read(regmap, DPS310_MEAS_CFG, &ready); > + if (r < 0) > + return r; > + if (!(ready & DPS310_TMP_RDY)) { > + dev_dbg(dev, "temperature not ready\n"); most drivers wait for the results to become ready > + return -EAGAIN; > + } > + > + r = regmap_bulk_read(regmap, DPS310_TMP_BASE, val, 3); sizeof(val) > + if (r < 0) > + return r; > + > + T_raw = (val[0] << 16) | (val[1] << 8) | val[2]; > + data->temp_raw = sign_extend32(T_raw, 23); > + > + return 0; > +} > + > +static bool dps310_is_writeable_reg(struct device *dev, unsigned int reg) > +{ > + switch (reg) { > + case DPS310_PRS_CFG: > + case DPS310_TMP_CFG: > + case DPS310_MEAS_CFG: > + case DPS310_CFG_REG: > + case DPS310_RESET: > + return true; > + default: > + return false; > + } > +} > + > +static bool dps310_is_volatile_reg(struct device *dev, unsigned int reg) > +{ > + switch (reg) { > + case DPS310_PRS_B0: > + case DPS310_PRS_B1: > + case DPS310_PRS_B2: > + case DPS310_TMP_B0: > + case DPS310_TMP_B1: > + case DPS310_TMP_B2: > + case DPS310_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; not needed, dead code > +} > + > +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; > + > + 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; one could try to avoid the multipliation here and somehow mangle it into _SCALE/_OFFSET > + return IIO_VAL_INT; > + > + case IIO_CHAN_INFO_OFFSET: > + ret = dps310_get_temp_k(data); > + if (ret < 0) > + return ret; > + > + *val = (data->c0 >> 1) * ret; > + return IIO_VAL_INT; > + > + case IIO_CHAN_INFO_SCALE: > + ret = dps310_get_temp_k(data); > + if (ret < 0) > + return ret; > + > + *val = 1000; /* milliCelsius per Celsius */ > + *val2 = ret; > + 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; not needed, dead code > +} > + > +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 = { > + .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, ready; > + > + 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); > + > + /* > + * Set up external (MEMS) temperature sensor in single sample, one > + * measurement per second mode > + */ > + r = regmap_write(data->regmap, DPS310_TMP_CFG, > + DPS310_TMP_EXT | DPS310_CALC_RATE(1) | > + DPS310_CALC_PRC(1)); > + if (r < 0) > + goto err; > + > + /* Temp shift is disabled when PRC <= 8 */ > + r = regmap_write_bits(data->regmap, DPS310_CFG_REG, > + DPS310_TMP_SHIFT_EN, 0); > + if (r < 0) > + goto err; > + > + /* Turn on temperature measurement in the background */ > + r = regmap_write_bits(data->regmap, DPS310_MEAS_CFG, > + DPS310_MEAS_CTRL_BITS, > + DPS310_TEMP_EN | DPS310_BACKGROUND); > + if (r < 0) > + goto err; > + > + /* > + * Calibration coefficients required for reporting temperature. > + * They are available 40ms after the device has started > + */ > + r = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready, > + ready & DPS310_COEF_RDY, 10000, 40000); > + if (r < 0) > + goto err; > + > + r = dps310_get_temp_coef(data); > + if (r < 0) > + goto err; > + > + r = devm_iio_device_register(&client->dev, iio); > + if (r) > + goto err; > + > + i2c_set_clientdata(client, iio); > + > + dev_info(&client->dev, "%s: sensor '%s'\n", dev_name(&iio->dev), > + client->name); don't clutter the log > + > + return 0; > + > +err: > + regmap_write(data->regmap, DPS310_RESET, DPS310_RESET_MAGIC); > + return r; > +} > + > +static int dps310_remove(struct i2c_client *client) > +{ > + struct dps310_data *data = i2c_get_clientdata(client); > + > + return regmap_write(data->regmap, DPS310_RESET, DPS310_RESET_MAGIC); > +} > + > +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, > + .remove = dps310_remove, > + .address_list = normal_i2c, > + .id_table = dps310_id, > +}; > +module_i2c_driver(dps310_driver); > + > +MODULE_AUTHOR("Joel Stanley <j...@jms.id.au>"); > +MODULE_DESCRIPTION("Infineon DPS310 pressure and temperature sensor"); > +MODULE_LICENSE("GPL v2"); > -- Peter Meerwald-Stadler Mobile: +43 664 24 44 418
