Messages in this thread | | | Subject | Re: [PATCH 1/3] iio: Add driver for Infineon DPS310 | From | Eddie James <> | Date | Tue, 7 May 2019 11:01:36 -0500 |
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On 5/6/19 4:18 PM, Peter Meerwald-Stadler wrote: > On Mon, 6 May 2019, Eddie James wrote: > >> From: Joel Stanley <joel@jms.id.au> > 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@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 <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..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?
> >> + 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...
> >> + 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@jms.id.au>"); >> +MODULE_DESCRIPTION("Infineon DPS310 pressure and temperature sensor"); >> +MODULE_LICENSE("GPL v2"); >>
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