On dom, 2022-07-17 at 16:08 +0100, Jonathan Cameron wrote: > On Sun, 10 Jul 2022 11:18:31 +0200 > Angel Iglesias <ang.iglesiasg@xxxxxxxxx> wrote: > > > Adds compatibility with the new generation of this sensor, the BMP380 > > > > Includes basic sensor initialization to do pressure and temp > > measurements and allows tuning oversampling settings for each channel. > > > > The compensation algorithms are adapted from the device datasheet and > > the repository https://github.com/BoschSensortec/BMP3-Sensor-API > > > > Signed-off-by: Angel Iglesias <ang.iglesiasg@xxxxxxxxx> > > Reported-by: kernel test robot <lkp@xxxxxxxxx> > > Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> > Say what was reported with # whatever > , or drop these tags. The message asking you to add them is applicable to > patches that are fixing things upstream. Adding them here implies that the > whole patch is a fix that was reported by the bots. > > One thing I'd previously missed in here is you are doing regmap_bulk_* > accesses. Those should be using dma safe buffer. Look for IIO_DMA_MINALIGN > in the current IIO togreg branch. > You can't safely use buffers on the stack. > > Otherwise, looks pretty good to me. > > Thanks, > > Jonathan > > > > --- > > drivers/iio/pressure/bmp280-core.c | 356 +++++++++++++++++++++++++++ > > drivers/iio/pressure/bmp280-i2c.c | 5 + > > drivers/iio/pressure/bmp280-regmap.c | 55 +++++ > > drivers/iio/pressure/bmp280-spi.c | 5 + > > drivers/iio/pressure/bmp280.h | 101 ++++++++ > > 5 files changed, 522 insertions(+) > > > > diff --git a/drivers/iio/pressure/bmp280-core.c > > b/drivers/iio/pressure/bmp280-core.c > > index 59e9c5fb4ab4..5d5d20d97cf6 100644 > > --- a/drivers/iio/pressure/bmp280-core.c > > +++ b/drivers/iio/pressure/bmp280-core.c > > @@ -12,10 +12,13 @@ > > * > > https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BMP180-DS000-121.pdf > > * > > https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BMP280-DS001-12.pdf > > * > > https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BME280_DS001-11.pdf > > + * > > https://www.bosch-sensortec.com/media/boschsensortec/downloads/datasheets/bst-bmp388-ds001.pdf > > */ > > > > #define pr_fmt(fmt) "bmp280: " fmt > > > > +#include <linux/bitops.h> > > +#include <linux/bitfield.h> > > #include <linux/device.h> > > #include <linux/module.h> > > #include <linux/regmap.h> > > @@ -29,6 +32,7 @@ > > #include <linux/completion.h> > > #include <linux/pm_runtime.h> > > #include <linux/random.h> > > +#include <asm/unaligned.h> > > > > #include "bmp280.h" > > > > @@ -74,6 +78,24 @@ struct bmp280_calib { > > s8 H6; > > }; > > > > +/* See datasheet Section 3.11.1. */ > > +struct bmp380_calib { > > + u16 T1; > > + u16 T2; > > + s8 T3; > > + s16 P1; > > + s16 P2; > > + s8 P3; > > + s8 P4; > > + u16 P5; > > + u16 P6; > > + s8 P7; > > + s8 P8; > > + s16 P9; > > + s8 P10; > > + s8 P11; > > +}; > > + > > static const char *const bmp280_supply_names[] = { > > "vddd", "vdda" > > }; > > @@ -90,6 +112,7 @@ struct bmp280_data { > > union { > > struct bmp180_calib bmp180; > > struct bmp280_calib bmp280; > > + struct bmp380_calib bmp380; > > } calib; > > struct regulator_bulk_data supplies[BMP280_NUM_SUPPLIES]; > > unsigned int start_up_time; /* in microseconds */ > > @@ -138,6 +161,25 @@ struct bmp280_chip_info { > > enum { T1, T2, T3 }; > > enum { P1, P2, P3, P4, P5, P6, P7, P8, P9 }; > > > > +enum { > > + /* Temperature calib indexes */ > > + BMP380_T1 = 0, > > + BMP380_T2 = 2, > > + BMP380_T3 = 4, > > + /* Pressure calib indexes */ > > + BMP380_P1 = 5, > > + BMP380_P2 = 7, > > + BMP380_P3 = 9, > > + BMP380_P4 = 10, > > + BMP380_P5 = 11, > > + BMP380_P6 = 13, > > + BMP380_P7 = 15, > > + BMP380_P8 = 16, > > + BMP380_P9 = 17, > > + BMP380_P10 = 19, > > + BMP380_P11 = 20 > > +}; > > + > > static const struct iio_chan_spec bmp280_channels[] = { > > { > > .type = IIO_PRESSURE, > > @@ -708,6 +750,310 @@ static const struct bmp280_chip_info bme280_chip_info > > = { > > .read_calib = bmp280_read_calib, > > }; > > > > +/* Send a command to BMP3XX sensors */ > > +static int bmp380_cmd(struct bmp280_data *data, u8 cmd) > > +{ > > + int ret; > > + unsigned int reg; > > + > > + /* check if device is ready to process a command */ > > + ret = regmap_read(data->regmap, BMP380_REG_STATUS, ®); > > + if (ret) { > > + dev_err(data->dev, "failed to read error register\n"); > > + return ret; > > + } > > + if (!(reg & BMP380_STATUS_CMD_RDY_MASK)) { > > + dev_err(data->dev, "device is not ready to accept > > commands\n"); > > + return -EBUSY; > > + } > > + > > + /* send command to process */ > > + ret = regmap_write(data->regmap, BMP380_REG_CMD, cmd); > > + if (ret) { > > + dev_err(data->dev, "failed to send command to device\n"); > > + return ret; > > + } > > + /* wait for 2ms for command to be proccessed */ > > + usleep_range(data->start_up_time, data->start_up_time + 100); > > + /* check for command processing error */ > > + ret = regmap_read(data->regmap, BMP380_REG_ERROR, ®); > > + if (ret) { > > + dev_err(data->dev, "error reading ERROR reg\n"); > > + return ret; > > + } > > + if (reg & BMP380_ERR_CMD_MASK) { > > + dev_err(data->dev, "error processing command 0x%X\n", cmd); > > + return -EINVAL; > > + } > > + dev_dbg(data->dev, "Command 0x%X proccessed successfully\n", cmd); > > + > > + return 0; > > +} > > + > > +/* > > + * Returns temperature in DegC, resolution is 0.01 DegC. Output value of > > + * "5123" equals 51.23 DegC. t_fine carries fine temperature as global > > + * value. > > + * > > + * Taken from datasheet, Section Appendix 9, "Compensation formula" and > > repo > > + * https://github.com/BoschSensortec/BMP3-Sensor-API > > + */ > > +static s32 bmp380_compensate_temp(struct bmp280_data *data, u32 adc_temp) > > +{ > > + s64 var1, var2, var3, var4, var5, var6, comp_temp; > > + struct bmp380_calib *calib = &data->calib.bmp380; > > + > > + var1 = ((s64) adc_temp) - (((s64) calib->T1) << 8); > > + var2 = var1 * ((s64) calib->T2); > > + var3 = var1 * var1; > > + var4 = var3 * ((s64) calib->T3); > > + var5 = (var2 << 18) + var4; > > + var6 = var5 >> 32; > > + data->t_fine = (s32) var6; > > + comp_temp = (var6 * 25) >> 14; > > + > > + comp_temp = clamp_val(comp_temp, BMP380_MIN_TEMP, BMP380_MAX_TEMP); > > + return (s32) comp_temp; > > +} > > + > > +/* > > + * Returns pressure in Pa as unsigned 32 bit integer in fractional Pascal. > > + * Output value of "9528709" represents 9528709/100 = 95287.09 Pa = > > 952.8709 hPa > > + * > > + * Taken from datasheet, Section 9.3. "Pressure compensation" and > > repository > > + * https://github.com/BoschSensortec/BMP3-Sensor-API > > + */ > > +static u32 bmp380_compensate_press(struct bmp280_data *data, u32 adc_press) > > +{ > > + s64 var1, var2, var3, var4, var5, var6, offset, sensitivity; > > + u64 comp_press; > > + struct bmp380_calib *calib = &data->calib.bmp380; > > + > > + var1 = ((s64)data->t_fine) * ((s64)data->t_fine); > > + var2 = var1 >> 6; > > + var3 = (var2 * ((s64) data->t_fine)) >> 8; > > + var4 = (((s64)calib->P8) * var3) >> 5; > > + var5 = (((s64) calib->P7) * var1) << 4; > > + var6 = (((s64) calib->P6) * ((s64)data->t_fine)) << 22; > > + offset = (((s64)calib->P5) << 47) + var4 + var5 + var6; > > + var2 = (((s64)calib->P4) * var3) >> 5; > > + var4 = (((s64) calib->P3) * var1) << 2; > > + var5 = (((s64) calib->P2) - ((s64) 1<<14)) * > > + (((s64)data->t_fine) << 21); > > + sensitivity = ((((s64) calib->P1) - ((s64) 1 << 14)) << 46) + > > + var2 + var4 + var5; > > + var1 = (sensitivity >> 24) * ((s64)adc_press); > > + var2 = ((s64)calib->P10) * ((s64) data->t_fine); > > + var3 = var2 + (((s64) calib->P9) << 16); > > + var4 = (var3 * ((s64)adc_press)) >> 13; > > + > > + /* > > + * Dividing by 10 followed by multiplying by 10 to avoid > > + * possible overflow caused by (uncomp_data->pressure * > > partial_data4) > > + */ > > + var5 = (((s64)adc_press) * (var4 / 10)) >> 9; > > + var5 *= 10; > > + var6 = ((s64)adc_press) * ((s64)adc_press); > > + var2 = (((s64)calib->P11) * var6) >> 16; > > + var3 = (var2 * ((s64)adc_press)) >> 7; > > + var4 = (offset >> 2) + var1 + var5 + var3; > > + comp_press = ((u64)var4 * 25) >> 40; > > + > > + comp_press = clamp_val(comp_press, BMP380_MIN_PRES, > > BMP380_MAX_PRES); > > + return (u32)comp_press; > > +} > > + > > +static int bmp380_read_temp(struct bmp280_data *data, int *val) > > +{ > > + int ret; > > + u8 tmp[3]; > > + u32 adc_temp; > > + s32 comp_temp; > > + > > + ret = regmap_bulk_read(data->regmap, BMP380_REG_TEMP_XLSB, tmp, 3); > As below. > > + if (ret < 0) { > > + dev_err(data->dev, "failed to read temperature\n"); > > + return ret; > > + } > > + > > + adc_temp = get_unaligned_le24(tmp); > > + if (adc_temp == BMP380_TEMP_SKIPPED) { > > + /* reading was skipped */ > > + dev_err(data->dev, "reading temperature skipped\n"); > > + return -EIO; > > + } > > + comp_temp = bmp380_compensate_temp(data, adc_temp); > > + > > + /* > > + * val might be NULL if we're called by the read_press routine, > > + * who only cares about the carry over t_fine value. > > + */ > > + if (val) { > > + /* IIO reports temperatures in mC */ > > + *val = comp_temp * 10; > > + return IIO_VAL_INT; > > + } > > + > > + return 0; > > +} > > + > > +static int bmp380_read_press(struct bmp280_data *data, int *val, int *val2) > > +{ > > + int ret; > > + u8 tmp[3]; > > + u32 adc_press; > > + s32 comp_press; > > + > > + /* Read and compensate temperature so we get a reading of t_fine. */ > > + ret = bmp380_read_temp(data, NULL); > > + if (ret < 0) > > + return ret; > > + > > + ret = regmap_bulk_read(data->regmap, BMP380_REG_PRESS_XLSB, tmp, 3); > > As below, buffer should be DMA safe. > > > + if (ret < 0) { > > + dev_err(data->dev, "failed to read pressure\n"); > > + return ret; > > + } > > + > > + adc_press = get_unaligned_le24(tmp); > > + if (adc_press == BMP380_PRESS_SKIPPED) { > > + /* reading was skipped */ > > + dev_err(data->dev, "reading pressure skipped\n"); > > + return -EIO; > > + } > > + comp_press = bmp380_compensate_press(data, adc_press); > > + > > + *val = comp_press; > > + /* Compensated pressure is in cPa (centipascals) */ > > + *val2 = 100000; > > + > > + return IIO_VAL_FRACTIONAL; > > +} > > + > > +static int bmp380_read_calib(struct bmp280_data *data, unsigned int chip) > > +{ > > + int ret; > > + struct bmp380_calib *calib = &data->calib.bmp380; > > + u8 buf[BMP380_CALIB_REG_COUNT]; > > I'd missed this previously but for SPI drivers, we should be providing > regmap_bulk accesses with DMA safe buffers. That means they can't be on the > stack and need to be appropriately aligned IIO_DMA_MINALIGN as part of > the *data structure. > > Last time I checked the SPI regmap implementation doesn't currently use > the buffers directly but it has in the past and may do again in the future > - hence we should be careful to allow for that. > As we only use this buffer once to store temporally the calibration data to parse, I would like to avoid adding extra overhead to the device data struct. I've been consulting on DMA rules and safety, and if I understood correctly (listed the sources below), it should be safe to use a buffer allocated at runtime with kmalloc, right? * https://elinux.org/images/0/03/20181023-Wolfram-Sang-ELCE18- safe_dma_buffers.pdf * https://linux-arm-kernel.infradead.narkive.com/vyJqy0RQ/question-devm- kmalloc-for-dma Thanks in advance, Angel > > + > > + /* Read temperature calibration values. */ > > + ret = regmap_bulk_read(data->regmap, BMP380_REG_CALIB_TEMP_START, > > buf, > > + BMP380_CALIB_REG_COUNT); > > + if (ret < 0) { > > + dev_err(data->dev, > > + "failed to read temperature calibration > > parameters\n"); > > + return ret; > > + } > > + > > + /* Toss the temperature calibration data into the entropy pool */ > > + add_device_randomness(buf, sizeof(buf)); > > + > > + /* Parse calibration data */ > > + calib->T1 = get_unaligned_le16(&buf[BMP380_T1]); > > + calib->T2 = get_unaligned_le16(&buf[BMP380_T2]); > > + calib->T3 = buf[BMP380_T3]; > > + calib->P1 = get_unaligned_le16(&buf[BMP380_P1]); > > + calib->P2 = get_unaligned_le16(&buf[BMP380_P2]); > > + calib->P3 = buf[BMP380_P3]; > > + calib->P4 = buf[BMP380_P4]; > > + calib->P5 = get_unaligned_le16(&buf[BMP380_P5]); > > + calib->P6 = get_unaligned_le16(&buf[BMP380_P6]); > > + calib->P7 = buf[BMP380_P7]; > > + calib->P8 = buf[BMP380_P8]; > > + calib->P9 = get_unaligned_le16(&buf[BMP380_P9]); > > + calib->P10 = buf[BMP380_P10]; > > + calib->P11 = buf[BMP380_P11]; > > + > > + return 0; > > +}
