On Tue, 7 May 2019 11:01:36 -0500 Eddie James <eajames@xxxxxxxxxxxxxxxxxx> wrote: > On 5/6/19 4:18 PM, Peter Meerwald-Stadler wrote: > > On Mon, 6 May 2019, Eddie James wrote: > > > >> From: Joel Stanley <joel@xxxxxxxxx> > > some comments below > > > Thanks for the quick review! Will get these in for v2, I did have a > couple of questions below though. > > Eddie > > > > > >> The DPS310 is a temperature and pressure sensor. It can be accessed over > >> i2c and SPI. > >> > >> Signed-off-by: Eddie James <eajames@xxxxxxxxxxxxx> > >> --- > >> 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 <eajames@xxxxxxxxxxxxx> > >> +L: linux-iio@xxxxxxxxxxxxxxx > >> +F: drivers/iio/pressure/dps310.c > >> +S: Maintained > >> + > >> INFINIBAND SUBSYSTEM > >> M: Doug Ledford <dledford@xxxxxxxxxx> > >> M: Jason Gunthorpe <jgg@xxxxxxxxxxxx> > >> 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\ > > > OK, this may have to wait up to a second then, since the background > measurement rate can be as low as 1 HZ... I can base the timeout on the > sample rate. Would that be OK? Yes. I may be that we actually want to pick a my power hungry and faster default to avoid any stupid userspace programs wondering why they don't get an answer for 1 second. > > > > > >> + 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 > > > Don't think it's worth it? Would have to divide the offset by c1 and > then multiply by c1 again in the scale... I think you are actually better just reporting as PROCESSED. > > > > > >> + 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 <joel@xxxxxxxxx>"); > >> +MODULE_DESCRIPTION("Infineon DPS310 pressure and temperature sensor"); > >> +MODULE_LICENSE("GPL v2"); > >> >
