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iio: Add driver for Infineon DPS310

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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>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Joel Stanley 2019-05-20 21:13:32 -05:00 committed by Jonathan Cameron
parent bc4054b55f
commit ba6ec48e76
4 changed files with 486 additions and 0 deletions
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6
MAINTAINERS
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@ -7761,6 +7761,12 @@ W: http://industrypack.sourceforge.net
S: Maintained S: Maintained
F: drivers/ipack/ 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 INFINIBAND SUBSYSTEM
M: Doug Ledford <dledford@redhat.com> M: Doug Ledford <dledford@redhat.com>
M: Jason Gunthorpe <jgg@mellanox.com> M: Jason Gunthorpe <jgg@mellanox.com>

11
drivers/iio/pressure/Kconfig
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@ -52,6 +52,17 @@ config IIO_CROS_EC_BARO
To compile this driver as a module, choose M here: the module To compile this driver as a module, choose M here: the module
will be called cros_ec_baro. 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 config HID_SENSOR_PRESS
depends on HID_SENSOR_HUB depends on HID_SENSOR_HUB
select IIO_BUFFER select IIO_BUFFER

1
drivers/iio/pressure/Makefile
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@ -9,6 +9,7 @@ obj-$(CONFIG_BMP280) += bmp280.o
bmp280-objs := bmp280-core.o bmp280-regmap.o bmp280-objs := bmp280-core.o bmp280-regmap.o
obj-$(CONFIG_BMP280_I2C) += bmp280-i2c.o obj-$(CONFIG_BMP280_I2C) += bmp280-i2c.o
obj-$(CONFIG_BMP280_SPI) += bmp280-spi.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_IIO_CROS_EC_BARO) += cros_ec_baro.o
obj-$(CONFIG_HID_SENSOR_PRESS) += hid-sensor-press.o obj-$(CONFIG_HID_SENSOR_PRESS) += hid-sensor-press.o
obj-$(CONFIG_HP03) += hp03.o obj-$(CONFIG_HP03) += hp03.o

468
drivers/iio/pressure/dps310.c Normal file
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@ -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");