| Message ID | 1558404814-26078-2-git-send-email-eajames@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | iio: Add driver for Infineon DPS310 | expand |
On Mon, 20 May 2019 21:13:32 -0500 Eddie James <eajames@linux.ibm.com> wrote: > From: Joel Stanley <joel@jms.id.au> > > The DPS310 is a temperature and pressure sensor. It can be accessed over > i2c and SPI, but this driver only supports polling over i2c. > > Signed-off-by: Eddie James <eajames@linux.ibm.com> > Signed-off-by: Joel Stanley <joel@jms.id.au> Applied to the togreg branch of iio.git and pushed out as testing for the autobuilders to play with it. Thanks, Jonathan > --- > MAINTAINERS | 6 + > drivers/iio/pressure/Kconfig | 11 + > drivers/iio/pressure/Makefile | 1 + > drivers/iio/pressure/dps310.c | 468 ++++++++++++++++++++++++++++++++++++++++++ > 4 files changed, 486 insertions(+) > create mode 100644 drivers/iio/pressure/dps310.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index a2cd369..091eb49 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -7760,6 +7760,12 @@ W: http://industrypack.sourceforge.net > S: Maintained > F: drivers/ipack/ > > +INFINEON DPS310 Driver > +M: Eddie James <eajames@linux.ibm.com> > +L: linux-iio@vger.kernel.org > +F: drivers/iio/pressure/dps310.c > +S: Maintained > + > INFINIBAND SUBSYSTEM > M: Doug Ledford <dledford@redhat.com> > M: Jason Gunthorpe <jgg@mellanox.com> > diff --git a/drivers/iio/pressure/Kconfig b/drivers/iio/pressure/Kconfig > index efeb89f..97976de 100644 > --- a/drivers/iio/pressure/Kconfig > +++ b/drivers/iio/pressure/Kconfig > @@ -52,6 +52,17 @@ 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. > + It can be accessed over I2C bus. > + > + 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..9acfccb > --- /dev/null > +++ b/drivers/iio/pressure/dps310.c > @@ -0,0 +1,468 @@ > +// 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_DEV_NAME "dps310" > + > +#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 0x09 > +#define DPS310_COEF_BASE 0x10 > +#define DPS310_COEF_SRC 0x28 > + > +/* Make sure sleep time is <= 20ms for usleep_range */ > +#define DPS310_POLL_SLEEP_US(t) min(20000, (t) / 8) > +/* Silently handle error in rate value here */ > +#define DPS310_POLL_TIMEOUT_US(rc) ((rc) <= 0 ? 1000000 : 1000000 / (rc)) > + > +#define DPS310_PRS_BASE DPS310_PRS_B0 > +#define DPS310_TMP_BASE DPS310_TMP_B0 > + > +/* > + * These values (defined in the spec) indicate how to scale the raw register > + * values for each level of precision available. > + */ > +static const int scale_factors[] = { > + 524288, > + 1572864, > + 3670016, > + 7864320, > + 253952, > + 516096, > + 1040384, > + 2088960, > +}; > + > +struct dps310_data { > + struct i2c_client *client; > + struct regmap *regmap; > + struct mutex lock; /* Lock for sequential HW access functions */ > + > + s32 c0, c1; > + s32 temp_raw; > +}; > + > +static const struct iio_chan_spec dps310_channels[] = { > + { > + .type = IIO_TEMP, > + .info_mask_separate = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO) | > + BIT(IIO_CHAN_INFO_SAMP_FREQ) | > + BIT(IIO_CHAN_INFO_PROCESSED), > + }, > +}; > + > +/* To be called after checking the COEF_RDY bit in MEAS_CFG */ > +static int dps310_get_temp_coef(struct dps310_data *data) > +{ > + int rc; > + u8 coef[3]; > + u32 c0, c1; > + > + /* > + * Read temperature calibration coefficients c0 and c1 from the > + * COEF register. The numbers are 12-bit 2's compliment numbers > + */ > + rc = regmap_bulk_read(data->regmap, DPS310_COEF_BASE, coef, > + sizeof(coef)); > + if (rc < 0) > + return rc; > + > + 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 rc; > + int val; > + > + rc = regmap_read(data->regmap, DPS310_TMP_CFG, &val); > + if (rc < 0) > + return rc; > + > + /* > + * Scale factor is bottom 4 bits of the register, but 1111 is > + * reserved so just grab bottom three > + */ > + return BIT(val & GENMASK(2, 0)); > +} > + > +/* Called with lock held */ > +static int dps310_set_temp_precision(struct dps310_data *data, int val) > +{ > + int rc; > + u8 shift_en; > + > + if (val < 0 || val > 128) > + return -EINVAL; > + > + shift_en = val >= 16 ? DPS310_TMP_SHIFT_EN : 0; > + rc = regmap_write_bits(data->regmap, DPS310_CFG_REG, > + DPS310_TMP_SHIFT_EN, shift_en); > + if (rc) > + return rc; > + > + return regmap_update_bits(data->regmap, DPS310_TMP_CFG, > + DPS310_TMP_PRC_BITS, ilog2(val)); > +} > + > +/* Called with lock held */ > +static int dps310_set_temp_samp_freq(struct dps310_data *data, int freq) > +{ > + u8 val; > + > + if (freq < 0 || freq > 128) > + return -EINVAL; > + > + val = ilog2(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 rc; > + int val; > + > + rc = regmap_read(data->regmap, DPS310_TMP_CFG, &val); > + if (rc < 0) > + return rc; > + > + return BIT((val & DPS310_TMP_RATE_BITS) >> 4); > +} > + > +static int dps310_get_temp_k(struct dps310_data *data) > +{ > + int rc = dps310_get_temp_precision(data); > + > + if (rc < 0) > + return rc; > + > + return scale_factors[ilog2(rc)]; > +} > + > +static int dps310_read_temp(struct dps310_data *data) > +{ > + int rc; > + int rate; > + int ready; > + int timeout; > + s32 raw; > + u8 val[3]; > + > + if (mutex_lock_interruptible(&data->lock)) > + return -EINTR; > + > + rate = dps310_get_temp_samp_freq(data); > + timeout = DPS310_POLL_TIMEOUT_US(rate); > + > + /* Poll for sensor readiness; base the timeout upon the sample rate. */ > + rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready, > + ready & DPS310_TMP_RDY, > + DPS310_POLL_SLEEP_US(timeout), timeout); > + if (rc < 0) > + goto done; > + > + rc = regmap_bulk_read(data->regmap, DPS310_TMP_BASE, val, sizeof(val)); > + if (rc < 0) > + goto done; > + > + raw = (val[0] << 16) | (val[1] << 8) | val[2]; > + data->temp_raw = sign_extend32(raw, 23); > + > +done: > + mutex_unlock(&data->lock); > + return rc; > +} > + > +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) > +{ > + int rc; > + struct dps310_data *data = iio_priv(iio); > + > + if (chan->type != IIO_TEMP) > + return -EINVAL; > + > + if (mutex_lock_interruptible(&data->lock)) > + return -EINTR; > + > + switch (mask) { > + case IIO_CHAN_INFO_SAMP_FREQ: > + rc = dps310_set_temp_samp_freq(data, val); > + break; > + > + case IIO_CHAN_INFO_OVERSAMPLING_RATIO: > + rc = dps310_set_temp_precision(data, val); > + break; > + > + default: > + rc = -EINVAL; > + break; > + } > + > + mutex_unlock(&data->lock); > + return rc; > +} > + > +static int dps310_calculate_temp(struct dps310_data *data) > +{ > + s64 c0; > + s64 t; > + int kt = dps310_get_temp_k(data); > + > + if (kt < 0) > + return kt; > + > + /* Obtain inverse-scaled offset */ > + c0 = div_s64((s64)kt * (s64)data->c0, 2); > + > + /* Add the offset to the unscaled temperature */ > + t = c0 + ((s64)data->temp_raw * (s64)data->c1); > + > + /* Convert to milliCelsius and scale the temperature */ > + return (int)div_s64(t * 1000LL, kt); > +} > + > +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 rc; > + > + switch (mask) { > + case IIO_CHAN_INFO_SAMP_FREQ: > + rc = dps310_get_temp_samp_freq(data); > + if (rc < 0) > + return rc; > + > + *val = rc; > + return IIO_VAL_INT; > + > + case IIO_CHAN_INFO_PROCESSED: > + rc = dps310_read_temp(data); > + if (rc) > + return rc; > + > + rc = dps310_calculate_temp(data); > + if (rc < 0) > + return rc; > + > + *val = rc; > + return IIO_VAL_INT; > + > + case IIO_CHAN_INFO_OVERSAMPLING_RATIO: > + rc = dps310_get_temp_precision(data); > + if (rc < 0) > + return rc; > + > + *val = rc; > + return IIO_VAL_INT; > + > + default: > + return -EINVAL; > + } > +} > + > +static void dps310_reset(void *action_data) > +{ > + struct dps310_data *data = action_data; > + > + regmap_write(data->regmap, DPS310_RESET, DPS310_RESET_MAGIC); > +} > + > +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 = DPS310_COEF_SRC, > +}; > + > +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 rc, ready; > + > + iio = devm_iio_device_alloc(&client->dev, sizeof(*data)); > + if (!iio) > + return -ENOMEM; > + > + data = iio_priv(iio); > + data->client = client; > + mutex_init(&data->lock); > + > + 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); > + > + /* Register to run the device reset when the device is removed */ > + rc = devm_add_action_or_reset(&client->dev, dps310_reset, data); > + if (rc) > + return rc; > + > + /* > + * Set up external (MEMS) temperature sensor in single sample, one > + * measurement per second mode > + */ > + rc = regmap_write(data->regmap, DPS310_TMP_CFG, DPS310_TMP_EXT); > + if (rc < 0) > + return rc; > + > + /* Temp shift is disabled when PRC <= 8 */ > + rc = regmap_write_bits(data->regmap, DPS310_CFG_REG, > + DPS310_TMP_SHIFT_EN, 0); > + if (rc < 0) > + return rc; > + > + /* MEAS_CFG doesn't update correctly unless first written with 0 */ > + rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG, > + DPS310_MEAS_CTRL_BITS, 0); > + if (rc < 0) > + return rc; > + > + /* Turn on temperature measurement in the background */ > + rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG, > + DPS310_MEAS_CTRL_BITS, > + DPS310_TEMP_EN | DPS310_BACKGROUND); > + if (rc < 0) > + return rc; > + > + /* > + * Calibration coefficients required for reporting temperature. > + * They are available 40ms after the device has started > + */ > + rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready, > + ready & DPS310_COEF_RDY, 10000, 40000); > + if (rc < 0) > + return rc; > + > + rc = dps310_get_temp_coef(data); > + if (rc < 0) > + return rc; > + > + rc = devm_iio_device_register(&client->dev, iio); > + if (rc) > + return rc; > + > + i2c_set_clientdata(client, iio); > + > + return 0; > +} > + > +static const struct i2c_device_id dps310_id[] = { > + { DPS310_DEV_NAME, 0 }, > + {} > +}; > +MODULE_DEVICE_TABLE(i2c, dps310_id); > + > +static struct i2c_driver dps310_driver = { > + .driver = { > + .name = DPS310_DEV_NAME, > + }, > + .probe = dps310_probe, > + .id_table = dps310_id, > +}; > +module_i2c_driver(dps310_driver); > + > +MODULE_AUTHOR("Joel Stanley <joel@jms.id.au>"); > +MODULE_DESCRIPTION("Infineon DPS310 pressure and temperature sensor"); > +MODULE_LICENSE("GPL v2");
diff --git a/MAINTAINERS b/MAINTAINERS index a2cd369..091eb49 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -7760,6 +7760,12 @@ W: http://industrypack.sourceforge.net S: Maintained F: drivers/ipack/ +INFINEON DPS310 Driver +M: Eddie James <eajames@linux.ibm.com> +L: linux-iio@vger.kernel.org +F: drivers/iio/pressure/dps310.c +S: Maintained + INFINIBAND SUBSYSTEM M: Doug Ledford <dledford@redhat.com> M: Jason Gunthorpe <jgg@mellanox.com> diff --git a/drivers/iio/pressure/Kconfig b/drivers/iio/pressure/Kconfig index efeb89f..97976de 100644 --- a/drivers/iio/pressure/Kconfig +++ b/drivers/iio/pressure/Kconfig @@ -52,6 +52,17 @@ 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. + It can be accessed over I2C bus. + + 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..9acfccb --- /dev/null +++ b/drivers/iio/pressure/dps310.c @@ -0,0 +1,468 @@ +// 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_DEV_NAME "dps310" + +#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 0x09 +#define DPS310_COEF_BASE 0x10 +#define DPS310_COEF_SRC 0x28 + +/* Make sure sleep time is <= 20ms for usleep_range */ +#define DPS310_POLL_SLEEP_US(t) min(20000, (t) / 8) +/* Silently handle error in rate value here */ +#define DPS310_POLL_TIMEOUT_US(rc) ((rc) <= 0 ? 1000000 : 1000000 / (rc)) + +#define DPS310_PRS_BASE DPS310_PRS_B0 +#define DPS310_TMP_BASE DPS310_TMP_B0 + +/* + * These values (defined in the spec) indicate how to scale the raw register + * values for each level of precision available. + */ +static const int scale_factors[] = { + 524288, + 1572864, + 3670016, + 7864320, + 253952, + 516096, + 1040384, + 2088960, +}; + +struct dps310_data { + struct i2c_client *client; + struct regmap *regmap; + struct mutex lock; /* Lock for sequential HW access functions */ + + s32 c0, c1; + s32 temp_raw; +}; + +static const struct iio_chan_spec dps310_channels[] = { + { + .type = IIO_TEMP, + .info_mask_separate = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO) | + BIT(IIO_CHAN_INFO_SAMP_FREQ) | + BIT(IIO_CHAN_INFO_PROCESSED), + }, +}; + +/* To be called after checking the COEF_RDY bit in MEAS_CFG */ +static int dps310_get_temp_coef(struct dps310_data *data) +{ + int rc; + u8 coef[3]; + u32 c0, c1; + + /* + * Read temperature calibration coefficients c0 and c1 from the + * COEF register. The numbers are 12-bit 2's compliment numbers + */ + rc = regmap_bulk_read(data->regmap, DPS310_COEF_BASE, coef, + sizeof(coef)); + if (rc < 0) + return rc; + + 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 rc; + int val; + + rc = regmap_read(data->regmap, DPS310_TMP_CFG, &val); + if (rc < 0) + return rc; + + /* + * Scale factor is bottom 4 bits of the register, but 1111 is + * reserved so just grab bottom three + */ + return BIT(val & GENMASK(2, 0)); +} + +/* Called with lock held */ +static int dps310_set_temp_precision(struct dps310_data *data, int val) +{ + int rc; + u8 shift_en; + + if (val < 0 || val > 128) + return -EINVAL; + + shift_en = val >= 16 ? DPS310_TMP_SHIFT_EN : 0; + rc = regmap_write_bits(data->regmap, DPS310_CFG_REG, + DPS310_TMP_SHIFT_EN, shift_en); + if (rc) + return rc; + + return regmap_update_bits(data->regmap, DPS310_TMP_CFG, + DPS310_TMP_PRC_BITS, ilog2(val)); +} + +/* Called with lock held */ +static int dps310_set_temp_samp_freq(struct dps310_data *data, int freq) +{ + u8 val; + + if (freq < 0 || freq > 128) + return -EINVAL; + + val = ilog2(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 rc; + int val; + + rc = regmap_read(data->regmap, DPS310_TMP_CFG, &val); + if (rc < 0) + return rc; + + return BIT((val & DPS310_TMP_RATE_BITS) >> 4); +} + +static int dps310_get_temp_k(struct dps310_data *data) +{ + int rc = dps310_get_temp_precision(data); + + if (rc < 0) + return rc; + + return scale_factors[ilog2(rc)]; +} + +static int dps310_read_temp(struct dps310_data *data) +{ + int rc; + int rate; + int ready; + int timeout; + s32 raw; + u8 val[3]; + + if (mutex_lock_interruptible(&data->lock)) + return -EINTR; + + rate = dps310_get_temp_samp_freq(data); + timeout = DPS310_POLL_TIMEOUT_US(rate); + + /* Poll for sensor readiness; base the timeout upon the sample rate. */ + rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready, + ready & DPS310_TMP_RDY, + DPS310_POLL_SLEEP_US(timeout), timeout); + if (rc < 0) + goto done; + + rc = regmap_bulk_read(data->regmap, DPS310_TMP_BASE, val, sizeof(val)); + if (rc < 0) + goto done; + + raw = (val[0] << 16) | (val[1] << 8) | val[2]; + data->temp_raw = sign_extend32(raw, 23); + +done: + mutex_unlock(&data->lock); + return rc; +} + +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) +{ + int rc; + struct dps310_data *data = iio_priv(iio); + + if (chan->type != IIO_TEMP) + return -EINVAL; + + if (mutex_lock_interruptible(&data->lock)) + return -EINTR; + + switch (mask) { + case IIO_CHAN_INFO_SAMP_FREQ: + rc = dps310_set_temp_samp_freq(data, val); + break; + + case IIO_CHAN_INFO_OVERSAMPLING_RATIO: + rc = dps310_set_temp_precision(data, val); + break; + + default: + rc = -EINVAL; + break; + } + + mutex_unlock(&data->lock); + return rc; +} + +static int dps310_calculate_temp(struct dps310_data *data) +{ + s64 c0; + s64 t; + int kt = dps310_get_temp_k(data); + + if (kt < 0) + return kt; + + /* Obtain inverse-scaled offset */ + c0 = div_s64((s64)kt * (s64)data->c0, 2); + + /* Add the offset to the unscaled temperature */ + t = c0 + ((s64)data->temp_raw * (s64)data->c1); + + /* Convert to milliCelsius and scale the temperature */ + return (int)div_s64(t * 1000LL, kt); +} + +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 rc; + + switch (mask) { + case IIO_CHAN_INFO_SAMP_FREQ: + rc = dps310_get_temp_samp_freq(data); + if (rc < 0) + return rc; + + *val = rc; + return IIO_VAL_INT; + + case IIO_CHAN_INFO_PROCESSED: + rc = dps310_read_temp(data); + if (rc) + return rc; + + rc = dps310_calculate_temp(data); + if (rc < 0) + return rc; + + *val = rc; + return IIO_VAL_INT; + + case IIO_CHAN_INFO_OVERSAMPLING_RATIO: + rc = dps310_get_temp_precision(data); + if (rc < 0) + return rc; + + *val = rc; + return IIO_VAL_INT; + + default: + return -EINVAL; + } +} + +static void dps310_reset(void *action_data) +{ + struct dps310_data *data = action_data; + + regmap_write(data->regmap, DPS310_RESET, DPS310_RESET_MAGIC); +} + +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 = DPS310_COEF_SRC, +}; + +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 rc, ready; + + iio = devm_iio_device_alloc(&client->dev, sizeof(*data)); + if (!iio) + return -ENOMEM; + + data = iio_priv(iio); + data->client = client; + mutex_init(&data->lock); + + 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); + + /* Register to run the device reset when the device is removed */ + rc = devm_add_action_or_reset(&client->dev, dps310_reset, data); + if (rc) + return rc; + + /* + * Set up external (MEMS) temperature sensor in single sample, one + * measurement per second mode + */ + rc = regmap_write(data->regmap, DPS310_TMP_CFG, DPS310_TMP_EXT); + if (rc < 0) + return rc; + + /* Temp shift is disabled when PRC <= 8 */ + rc = regmap_write_bits(data->regmap, DPS310_CFG_REG, + DPS310_TMP_SHIFT_EN, 0); + if (rc < 0) + return rc; + + /* MEAS_CFG doesn't update correctly unless first written with 0 */ + rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG, + DPS310_MEAS_CTRL_BITS, 0); + if (rc < 0) + return rc; + + /* Turn on temperature measurement in the background */ + rc = regmap_write_bits(data->regmap, DPS310_MEAS_CFG, + DPS310_MEAS_CTRL_BITS, + DPS310_TEMP_EN | DPS310_BACKGROUND); + if (rc < 0) + return rc; + + /* + * Calibration coefficients required for reporting temperature. + * They are available 40ms after the device has started + */ + rc = regmap_read_poll_timeout(data->regmap, DPS310_MEAS_CFG, ready, + ready & DPS310_COEF_RDY, 10000, 40000); + if (rc < 0) + return rc; + + rc = dps310_get_temp_coef(data); + if (rc < 0) + return rc; + + rc = devm_iio_device_register(&client->dev, iio); + if (rc) + return rc; + + i2c_set_clientdata(client, iio); + + return 0; +} + +static const struct i2c_device_id dps310_id[] = { + { DPS310_DEV_NAME, 0 }, + {} +}; +MODULE_DEVICE_TABLE(i2c, dps310_id); + +static struct i2c_driver dps310_driver = { + .driver = { + .name = DPS310_DEV_NAME, + }, + .probe = dps310_probe, + .id_table = dps310_id, +}; +module_i2c_driver(dps310_driver); + +MODULE_AUTHOR("Joel Stanley <joel@jms.id.au>"); +MODULE_DESCRIPTION("Infineon DPS310 pressure and temperature sensor"); +MODULE_LICENSE("GPL v2");