[PATCH v4 0/5] Add support for pressure sensor Bosch BMP380

[PATCH v4 0/5] Add support for pressure sensor Bosch BMP380

[Angel Iglesias]

This patchset adds BMP380 variant to the already existing drivers for
the Bosch BMP180/280 pressure sensors.

Patch 1 adds references and sensor id to the devicetree bindings docs.
Patch 2 is a minor refactor simplifying driver initialization logic
to facilitate the integration of the new sensor variant extending the
information stored in the "chip_info" struct.
Patch 3 fixes DMA unsafe regmap_bulk_* calls reported by Jonathan Cameron
<jic23@kernel.org>.
Patch 4 adds the basic logic to initialize and read measurements from
the sensor.
Patch 5 adds advanced configurable features such as sampling frequency
and IIR filter through the IIO sysfs ABI.

Changes in v4:
 - Patch 4 and 2: Merged v3 patch 2 (Kconfig refs update) into this patch.
 - Patch 3: Added patch fixing unsafe DMA regmap_bulk_* calls reported by
    Jonathan Cameron <jic23@kernel.org>.
 - Patch 4: Fixed DMA unsafe buffers used on regmap_bulk_* calls reported
    by Jonathan Cameron <jic23@kernel.org>.

Changes in v3:
 - Patch 2: Fixed incorrect abbreviation.
 - Patch 3: use dev_err_probe helper to handle error initializing sensor.
 - Patch 4: Fixed kernel test robot warning provoked by missing include.
 - Patch 4: Fixed bug reported by Dan Carpenter <dan.carpenter@oracle.com>.
 - Patch 5: Fixed formatting and typos on multiple comments.
 - Patch 5: Fixed missing boolean initialization reported by
    Andy Shevchenko <andy.shevchenko@gmail.com>.
 - Patch 5: Replaced duplicated comments with a single comment containing
    a brief explantation in a shared location.
 - Patch 5: Dropped incorrect use of unlikely macro.

Changes in v2:
 - Added patch 2 updating Kconfig with references to new sensor.
 - Patch 3 adds changes proposed by Jonathan Cameron <jic23@kernel.org>
    to declutter and unify configuration logic for the different sensors
    extending "chip_info" struct with default configuration parameters.
 - Patch 4: store temperature and pressure adc values on 3 byte array
    instead of using the type __le32. Uses function get_unaligned_le24
    to convert the little-endian encoded 3 byte value to an integer.
 - Patch 4: drops custom macro le16_from_bytes and use get_unaligned_le16.
 - Patch 4: generate masks using GENMASK macro.
 - Patch 4: use FIELD_PREP to generate bitfields for registries.
 - Patch 4: dropped stray formatting change.
 - Patch 5: adds sanity checks in bmp280_read_raw for channel properties
   only available in the BMP380.
 - Patch 5: on bmp280_write_* checks if a problem ocurred committing new
    configuration and tries to restore previous working configuration
    to keep the sensor in a previous working state.
 - Patch 5: refactored bmp380_chip_config to only check for configuration
    errors when a configuration change is detected.
 - Patch 5: improved invalid configuration detection on BMP380 restarting
    measurement loop to force a new measurement after the configuration is
    updated.

Angel Iglesias (5):
  dt-bindings: iio: pressure: bmp085: Add BMP380 compatible string
  iio: pressure: bmp280: simplify driver initialization logic
  iio: pressure: bmp280: Fix alignment for DMA safety
  iio: pressure: bmp280: Add support for BMP380 sensor family
  iio: pressure: bmp280: Add more tunable config parameters for BMP380

 .../bindings/iio/pressure/bmp085.yaml         |   4 +-
 drivers/iio/pressure/Kconfig                  |   6 +-
 drivers/iio/pressure/bmp280-core.c            | 884 ++++++++++++++++--
 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                 |  83 ++
 7 files changed, 937 insertions(+), 105 deletions(-)


base-commit: 180c6cb6b9b79c55b79e8414f4c0208f2463af7d
-- 
2.37.1

[PATCH v4 1/5] dt-bindings: iio: pressure: bmp085: Add BMP380 compatible string

[Angel Iglesias]

Add bosch,bmp380 compatible string for the new family of sensors.
This family includes the BMP380, BMP384 and BMP388. The register map
in this family changes substantially and introduces new features
but core concepts and operations carryover from the previous iterations

Signed-off-by: Angel Iglesias <ang.iglesiasg@gmail.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
---
 Documentation/devicetree/bindings/iio/pressure/bmp085.yaml | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/iio/pressure/bmp085.yaml b/Documentation/devicetree/bindings/iio/pressure/bmp085.yaml
index 49257f9251e8..72cd2c2d3f17 100644
--- a/Documentation/devicetree/bindings/iio/pressure/bmp085.yaml
+++ b/Documentation/devicetree/bindings/iio/pressure/bmp085.yaml
@@ -4,7 +4,7 @@
 $id: http://devicetree.org/schemas/iio/pressure/bmp085.yaml#
 $schema: http://devicetree.org/meta-schemas/core.yaml#
 
-title: BMP085/BMP180/BMP280/BME280 pressure iio sensors
+title: BMP085/BMP180/BMP280/BME280/BMP380 pressure iio sensors
 
 maintainers:
   - Andreas Klinger <ak@it-klinger.de>
@@ -16,6 +16,7 @@ description: |
     https://www.bosch-sensortec.com/bst/products/all_products/bmp180
     https://www.bosch-sensortec.com/bst/products/all_products/bmp280
     https://www.bosch-sensortec.com/bst/products/all_products/bme280
+    https://www.bosch-sensortec.com/bst/products/all_products/bmp380
 
 properties:
   compatible:
@@ -24,6 +25,7 @@ properties:
       - bosch,bmp180
       - bosch,bmp280
       - bosch,bme280
+      - bosch,bmp380
 
   reg:
     maxItems: 1
-- 
2.37.1

[PATCH v4 2/5] iio: pressure: bmp280: simplify driver initialization logic

[Angel Iglesias]

Simplified common initialization logic of different sensor types
unifying calibration and initial configuration recovery.

Default config param values of each sensor type are stored inside
chip_info structure and used to initialize sensor data struct instance.

The auxiliar functions for read each sensor type calibration are converted
to a callback available on the chip_info struct.

Suggested-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Angel Iglesias <ang.iglesiasg@gmail.com>
---
 drivers/iio/pressure/bmp280-core.c | 91 ++++++++++++++++++------------
 1 file changed, 54 insertions(+), 37 deletions(-)

diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
index fe7aa81e7cc9..60fba199c7a0 100644
--- a/drivers/iio/pressure/bmp280-core.c
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -107,19 +107,28 @@ struct bmp280_data {
 };
 
 struct bmp280_chip_info {
+	unsigned int id_reg;
+
+	int num_channels;
+	unsigned int start_up_time;
+
 	const int *oversampling_temp_avail;
 	int num_oversampling_temp_avail;
+	int oversampling_temp_default;
 
 	const int *oversampling_press_avail;
 	int num_oversampling_press_avail;
+	int oversampling_press_default;
 
 	const int *oversampling_humid_avail;
 	int num_oversampling_humid_avail;
+	int oversampling_humid_default;
 
 	int (*chip_config)(struct bmp280_data *);
 	int (*read_temp)(struct bmp280_data *, int *);
 	int (*read_press)(struct bmp280_data *, int *, int *);
 	int (*read_humid)(struct bmp280_data *, int *, int *);
+	int (*read_calib)(struct bmp280_data *, unsigned int);
 };
 
 /*
@@ -147,15 +156,14 @@ static const struct iio_chan_spec bmp280_channels[] = {
 	},
 };
 
-static int bmp280_read_calib(struct bmp280_data *data,
-			     struct bmp280_calib *calib,
-			     unsigned int chip)
+static int bmp280_read_calib(struct bmp280_data *data, unsigned int chip)
 {
 	int ret;
 	unsigned int tmp;
 	__le16 l16;
 	__be16 b16;
 	struct device *dev = data->dev;
+	struct bmp280_calib *calib = &data->calib.bmp280;
 	__le16 t_buf[BMP280_COMP_TEMP_REG_COUNT / 2];
 	__le16 p_buf[BMP280_COMP_PRESS_REG_COUNT / 2];
 
@@ -640,15 +648,22 @@ static int bmp280_chip_config(struct bmp280_data *data)
 static const int bmp280_oversampling_avail[] = { 1, 2, 4, 8, 16 };
 
 static const struct bmp280_chip_info bmp280_chip_info = {
+	.id_reg = BMP280_REG_ID,
+	.start_up_time = 2000,
+	.num_channels = 2,
+
 	.oversampling_temp_avail = bmp280_oversampling_avail,
 	.num_oversampling_temp_avail = ARRAY_SIZE(bmp280_oversampling_avail),
+	.oversampling_temp_default = ilog2(2),
 
 	.oversampling_press_avail = bmp280_oversampling_avail,
 	.num_oversampling_press_avail = ARRAY_SIZE(bmp280_oversampling_avail),
+	.oversampling_press_default = ilog2(16),
 
 	.chip_config = bmp280_chip_config,
 	.read_temp = bmp280_read_temp,
 	.read_press = bmp280_read_press,
+	.read_calib = bmp280_read_calib,
 };
 
 static int bme280_chip_config(struct bmp280_data *data)
@@ -670,19 +685,27 @@ static int bme280_chip_config(struct bmp280_data *data)
 }
 
 static const struct bmp280_chip_info bme280_chip_info = {
+	.id_reg = BMP280_REG_ID,
+	.start_up_time = 2000,
+	.num_channels = 3,
+
 	.oversampling_temp_avail = bmp280_oversampling_avail,
 	.num_oversampling_temp_avail = ARRAY_SIZE(bmp280_oversampling_avail),
+	.oversampling_temp_default = ilog2(2),
 
 	.oversampling_press_avail = bmp280_oversampling_avail,
 	.num_oversampling_press_avail = ARRAY_SIZE(bmp280_oversampling_avail),
+	.oversampling_press_default = ilog2(16),
 
 	.oversampling_humid_avail = bmp280_oversampling_avail,
 	.num_oversampling_humid_avail = ARRAY_SIZE(bmp280_oversampling_avail),
+	.oversampling_humid_default = ilog2(16),
 
 	.chip_config = bme280_chip_config,
 	.read_temp = bmp280_read_temp,
 	.read_press = bmp280_read_press,
 	.read_humid = bmp280_read_humid,
+	.read_calib = bmp280_read_calib,
 };
 
 static int bmp180_measure(struct bmp280_data *data, u8 ctrl_meas)
@@ -748,11 +771,11 @@ static int bmp180_read_adc_temp(struct bmp280_data *data, int *val)
 	return 0;
 }
 
-static int bmp180_read_calib(struct bmp280_data *data,
-			     struct bmp180_calib *calib)
+static int bmp180_read_calib(struct bmp280_data *data, unsigned int chip)
 {
 	int ret;
 	int i;
+	struct bmp180_calib *calib = &data->calib.bmp180;
 	__be16 buf[BMP180_REG_CALIB_COUNT / 2];
 
 	ret = regmap_bulk_read(data->regmap, BMP180_REG_CALIB_START, buf,
@@ -913,17 +936,24 @@ static const int bmp180_oversampling_temp_avail[] = { 1 };
 static const int bmp180_oversampling_press_avail[] = { 1, 2, 4, 8 };
 
 static const struct bmp280_chip_info bmp180_chip_info = {
+	.id_reg = BMP280_REG_ID,
+	.start_up_time = 2000,
+	.num_channels = 2,
+
 	.oversampling_temp_avail = bmp180_oversampling_temp_avail,
 	.num_oversampling_temp_avail =
 		ARRAY_SIZE(bmp180_oversampling_temp_avail),
+	.oversampling_temp_default = ilog2(1),
 
 	.oversampling_press_avail = bmp180_oversampling_press_avail,
 	.num_oversampling_press_avail =
 		ARRAY_SIZE(bmp180_oversampling_press_avail),
+	.oversampling_press_default = ilog2(8),
 
 	.chip_config = bmp180_chip_config,
 	.read_temp = bmp180_read_temp,
 	.read_press = bmp180_read_press,
+	.read_calib = bmp180_read_calib,
 };
 
 static irqreturn_t bmp085_eoc_irq(int irq, void *d)
@@ -993,6 +1023,7 @@ int bmp280_common_probe(struct device *dev,
 	int ret;
 	struct iio_dev *indio_dev;
 	struct bmp280_data *data;
+	const struct bmp280_chip_info *chip_info;
 	unsigned int chip_id;
 	struct gpio_desc *gpiod;
 
@@ -1011,30 +1042,25 @@ int bmp280_common_probe(struct device *dev,
 
 	switch (chip) {
 	case BMP180_CHIP_ID:
-		indio_dev->num_channels = 2;
-		data->chip_info = &bmp180_chip_info;
-		data->oversampling_press = ilog2(8);
-		data->oversampling_temp = ilog2(1);
-		data->start_up_time = 10000;
+		chip_info = &bmp180_chip_info;
 		break;
 	case BMP280_CHIP_ID:
-		indio_dev->num_channels = 2;
-		data->chip_info = &bmp280_chip_info;
-		data->oversampling_press = ilog2(16);
-		data->oversampling_temp = ilog2(2);
-		data->start_up_time = 2000;
+		chip_info = &bmp280_chip_info;
 		break;
 	case BME280_CHIP_ID:
-		indio_dev->num_channels = 3;
-		data->chip_info = &bme280_chip_info;
-		data->oversampling_press = ilog2(16);
-		data->oversampling_humid = ilog2(16);
-		data->oversampling_temp = ilog2(2);
-		data->start_up_time = 2000;
+		chip_info = &bme280_chip_info;
 		break;
 	default:
 		return -EINVAL;
 	}
+	data->chip_info = chip_info;
+
+	/* apply initial values from chip info structure */
+	indio_dev->num_channels = chip_info->num_channels;
+	data->oversampling_press = chip_info->oversampling_press_default;
+	data->oversampling_humid = chip_info->oversampling_humid_default;
+	data->oversampling_temp = chip_info->oversampling_temp_default;
+	data->start_up_time = chip_info->start_up_time;
 
 	/* Bring up regulators */
 	regulator_bulk_set_supply_names(data->supplies,
@@ -1071,7 +1097,8 @@ int bmp280_common_probe(struct device *dev,
 	}
 
 	data->regmap = regmap;
-	ret = regmap_read(regmap, BMP280_REG_ID, &chip_id);
+
+	ret = regmap_read(regmap, data->chip_info->id_reg, &chip_id);
 	if (ret < 0)
 		return ret;
 	if (chip_id != chip) {
@@ -1091,21 +1118,11 @@ int bmp280_common_probe(struct device *dev,
 	 * non-volatile memory during production". Let's read them out at probe
 	 * time once. They will not change.
 	 */
-	if (chip_id  == BMP180_CHIP_ID) {
-		ret = bmp180_read_calib(data, &data->calib.bmp180);
-		if (ret < 0) {
-			dev_err(data->dev,
-				"failed to read calibration coefficients\n");
-			return ret;
-		}
-	} else if (chip_id == BMP280_CHIP_ID || chip_id == BME280_CHIP_ID) {
-		ret = bmp280_read_calib(data, &data->calib.bmp280, chip_id);
-		if (ret < 0) {
-			dev_err(data->dev,
-				"failed to read calibration coefficients\n");
-			return ret;
-		}
-	}
+
+	ret = data->chip_info->read_calib(data, chip_id);
+	if (ret < 0)
+		return dev_err_probe(data->dev, ret,
+				     "failed to read calibration coefficients\n");
 
 	/*
 	 * Attempt to grab an optional EOC IRQ - only the BMP085 has this
-- 
2.37.1

Re: [PATCH v4 2/5] iio: pressure: bmp280: simplify driver initialization logic

[Andy Shevchenko]

On Sat, Jul 23, 2022 at 7:40 PM Angel Iglesias <ang.iglesiasg@gmail.com> wrote:
>
> Simplified common initialization logic of different sensor types
> unifying calibration and initial configuration recovery.
>
> Default config param values of each sensor type are stored inside
> chip_info structure and used to initialize sensor data struct instance.
>
> The auxiliar functions for read each sensor type calibration are converted
> to a callback available on the chip_info struct.

...

> +       .oversampling_temp_default = ilog2(2),
> +       .oversampling_press_default = ilog2(16),
> +       .oversampling_humid_default = ilog2(16),
> +       .oversampling_temp_default = ilog2(1),
> +       .oversampling_press_default = ilog2(8),

It's a very interesting way of writing BIT(x)...

-- 
With Best Regards,
Andy Shevchenko

[PATCH v4 3/5] iio: pressure: bmp280: Fix alignment for DMA safety

[Angel Iglesias]

Adds a DMA-safe buffer to driver data struct to store raw data from sensor

Updated calibration read functions to use DMA-safe buffers as well.
In this case, as calibration data is only read at sensor initialization,
the buffers are allocated with kmalloc and freed after being processed.

Suggested-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Angel Iglesias <ang.iglesiasg@gmail.com>
---
 drivers/iio/pressure/bmp280-core.c | 164 ++++++++++++++++++-----------
 1 file changed, 103 insertions(+), 61 deletions(-)

diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
index 60fba199c7a0..9311eeec8473 100644
--- a/drivers/iio/pressure/bmp280-core.c
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -29,6 +29,7 @@
 #include <linux/completion.h>
 #include <linux/pm_runtime.h>
 #include <linux/random.h>
+#include <asm/unaligned.h>
 
 #include "bmp280.h"
 
@@ -36,7 +37,19 @@
  * These enums are used for indexing into the array of calibration
  * coefficients for BMP180.
  */
-enum { AC1, AC2, AC3, AC4, AC5, AC6, B1, B2, MB, MC, MD };
+enum {
+	AC1 = 0,
+	AC2 = 2,
+	AC3 = 4,
+	AC4 = 6,
+	AC5 = 8,
+	AC6 = 10,
+	B1 = 12,
+	B2 = 14,
+	MB = 16,
+	MC = 18,
+	MD = 20,
+};
 
 struct bmp180_calib {
 	s16 AC1;
@@ -104,6 +117,12 @@ struct bmp280_data {
 	 * calculation.
 	 */
 	s32 t_fine;
+
+	/*
+	 * DMA (thus cache coherency maintenance) may require the
+	 * transfer buffers to live in their own cache lines.
+	 */
+	u8 buf[3] __aligned(IIO_DMA_MINALIGN);
 };
 
 struct bmp280_chip_info {
@@ -135,8 +154,18 @@ struct bmp280_chip_info {
  * These enums are used for indexing into the array of compensation
  * parameters for BMP280.
  */
-enum { T1, T2, T3 };
-enum { P1, P2, P3, P4, P5, P6, P7, P8, P9 };
+enum { T1 = 0, T2 = 2, T3 = 4 };
+enum {
+	P1 = 0,
+	P2 = 2,
+	P3 = 4,
+	P4 = 6,
+	P5 = 8,
+	P6 = 10,
+	P7 = 12,
+	P8 = 14,
+	P9 = 16,
+};
 
 static const struct iio_chan_spec bmp280_channels[] = {
 	{
@@ -159,51 +188,59 @@ static const struct iio_chan_spec bmp280_channels[] = {
 static int bmp280_read_calib(struct bmp280_data *data, unsigned int chip)
 {
 	int ret;
+	u8 *t_buf;
+	u8 *p_buf;
 	unsigned int tmp;
-	__le16 l16;
-	__be16 b16;
 	struct device *dev = data->dev;
 	struct bmp280_calib *calib = &data->calib.bmp280;
-	__le16 t_buf[BMP280_COMP_TEMP_REG_COUNT / 2];
-	__le16 p_buf[BMP280_COMP_PRESS_REG_COUNT / 2];
 
+	t_buf = kmalloc(BMP280_COMP_TEMP_REG_COUNT, GFP_KERNEL);
+	if (!t_buf)
+		return -ENOMEM;
 	/* Read temperature calibration values. */
 	ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_TEMP_START,
 			       t_buf, BMP280_COMP_TEMP_REG_COUNT);
 	if (ret < 0) {
 		dev_err(data->dev,
 			"failed to read temperature calibration parameters\n");
+		kfree(t_buf);
 		return ret;
 	}
 
 	/* Toss the temperature calibration data into the entropy pool */
 	add_device_randomness(t_buf, sizeof(t_buf));
 
-	calib->T1 = le16_to_cpu(t_buf[T1]);
-	calib->T2 = le16_to_cpu(t_buf[T2]);
-	calib->T3 = le16_to_cpu(t_buf[T3]);
+	calib->T1 = get_unaligned_le16(&t_buf[T1]);
+	calib->T2 = get_unaligned_le16(&t_buf[T2]);
+	calib->T3 = get_unaligned_le16(&t_buf[T3]);
+	kfree(t_buf);
 
+	p_buf = kmalloc(BMP280_COMP_PRESS_REG_COUNT, GFP_KERNEL);
+	if (!p_buf)
+		return -ENOMEM;
 	/* Read pressure calibration values. */
 	ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_PRESS_START,
 			       p_buf, BMP280_COMP_PRESS_REG_COUNT);
 	if (ret < 0) {
 		dev_err(data->dev,
 			"failed to read pressure calibration parameters\n");
+		kfree(p_buf);
 		return ret;
 	}
 
 	/* Toss the pressure calibration data into the entropy pool */
 	add_device_randomness(p_buf, sizeof(p_buf));
 
-	calib->P1 = le16_to_cpu(p_buf[P1]);
-	calib->P2 = le16_to_cpu(p_buf[P2]);
-	calib->P3 = le16_to_cpu(p_buf[P3]);
-	calib->P4 = le16_to_cpu(p_buf[P4]);
-	calib->P5 = le16_to_cpu(p_buf[P5]);
-	calib->P6 = le16_to_cpu(p_buf[P6]);
-	calib->P7 = le16_to_cpu(p_buf[P7]);
-	calib->P8 = le16_to_cpu(p_buf[P8]);
-	calib->P9 = le16_to_cpu(p_buf[P9]);
+	calib->P1 = get_unaligned_le16(&p_buf[P1]);
+	calib->P2 = get_unaligned_le16(&p_buf[P2]);
+	calib->P3 = get_unaligned_le16(&p_buf[P3]);
+	calib->P4 = get_unaligned_le16(&p_buf[P4]);
+	calib->P5 = get_unaligned_le16(&p_buf[P5]);
+	calib->P6 = get_unaligned_le16(&p_buf[P6]);
+	calib->P7 = get_unaligned_le16(&p_buf[P7]);
+	calib->P8 = get_unaligned_le16(&p_buf[P8]);
+	calib->P9 = get_unaligned_le16(&p_buf[P9]);
+	kfree(p_buf);
 
 	/*
 	 * Read humidity calibration values.
@@ -222,12 +259,12 @@ static int bmp280_read_calib(struct bmp280_data *data, unsigned int chip)
 	}
 	calib->H1 = tmp;
 
-	ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H2, &l16, 2);
+	ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H2, data->buf, 2);
 	if (ret < 0) {
 		dev_err(dev, "failed to read H2 comp value\n");
 		return ret;
 	}
-	calib->H2 = sign_extend32(le16_to_cpu(l16), 15);
+	calib->H2 = get_unaligned_le16(data->buf);
 
 	ret = regmap_read(data->regmap, BMP280_REG_COMP_H3, &tmp);
 	if (ret < 0) {
@@ -236,20 +273,20 @@ static int bmp280_read_calib(struct bmp280_data *data, unsigned int chip)
 	}
 	calib->H3 = tmp;
 
-	ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H4, &b16, 2);
+	ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H4, data->buf, 2);
 	if (ret < 0) {
 		dev_err(dev, "failed to read H4 comp value\n");
 		return ret;
 	}
-	calib->H4 = sign_extend32(((be16_to_cpu(b16) >> 4) & 0xff0) |
-				  (be16_to_cpu(b16) & 0xf), 11);
+	calib->H4 = sign_extend32(((get_unaligned_be16(data->buf) >> 4) & 0xff0) |
+				  (get_unaligned_be16(data->buf) & 0xf), 11);
 
-	ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H5, &l16, 2);
+	ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H5, data->buf, 2);
 	if (ret < 0) {
 		dev_err(dev, "failed to read H5 comp value\n");
 		return ret;
 	}
-	calib->H5 = sign_extend32(((le16_to_cpu(l16) >> 4) & 0xfff), 11);
+	calib->H5 = sign_extend32(((get_unaligned_le16(data->buf) >> 4) & 0xfff), 11);
 
 	ret = regmap_read(data->regmap, BMP280_REG_COMP_H6, &tmp);
 	if (ret < 0) {
@@ -344,16 +381,15 @@ static int bmp280_read_temp(struct bmp280_data *data,
 			    int *val)
 {
 	int ret;
-	__be32 tmp = 0;
 	s32 adc_temp, comp_temp;
 
-	ret = regmap_bulk_read(data->regmap, BMP280_REG_TEMP_MSB, &tmp, 3);
+	ret = regmap_bulk_read(data->regmap, BMP280_REG_TEMP_MSB, data->buf, 3);
 	if (ret < 0) {
 		dev_err(data->dev, "failed to read temperature\n");
 		return ret;
 	}
 
-	adc_temp = be32_to_cpu(tmp) >> 12;
+	adc_temp = get_unaligned_be24(data->buf) >> 4;
 	if (adc_temp == BMP280_TEMP_SKIPPED) {
 		/* reading was skipped */
 		dev_err(data->dev, "reading temperature skipped\n");
@@ -377,7 +413,6 @@ static int bmp280_read_press(struct bmp280_data *data,
 			     int *val, int *val2)
 {
 	int ret;
-	__be32 tmp = 0;
 	s32 adc_press;
 	u32 comp_press;
 
@@ -386,13 +421,13 @@ static int bmp280_read_press(struct bmp280_data *data,
 	if (ret < 0)
 		return ret;
 
-	ret = regmap_bulk_read(data->regmap, BMP280_REG_PRESS_MSB, &tmp, 3);
+	ret = regmap_bulk_read(data->regmap, BMP280_REG_PRESS_MSB, data->buf, 3);
 	if (ret < 0) {
 		dev_err(data->dev, "failed to read pressure\n");
 		return ret;
 	}
 
-	adc_press = be32_to_cpu(tmp) >> 12;
+	adc_press = get_unaligned_be24(data->buf) >> 4;
 	if (adc_press == BMP280_PRESS_SKIPPED) {
 		/* reading was skipped */
 		dev_err(data->dev, "reading pressure skipped\n");
@@ -408,7 +443,6 @@ static int bmp280_read_press(struct bmp280_data *data,
 
 static int bmp280_read_humid(struct bmp280_data *data, int *val, int *val2)
 {
-	__be16 tmp;
 	int ret;
 	s32 adc_humidity;
 	u32 comp_humidity;
@@ -418,13 +452,13 @@ static int bmp280_read_humid(struct bmp280_data *data, int *val, int *val2)
 	if (ret < 0)
 		return ret;
 
-	ret = regmap_bulk_read(data->regmap, BMP280_REG_HUMIDITY_MSB, &tmp, 2);
+	ret = regmap_bulk_read(data->regmap, BMP280_REG_HUMIDITY_MSB, data->buf, 2);
 	if (ret < 0) {
 		dev_err(data->dev, "failed to read humidity\n");
 		return ret;
 	}
 
-	adc_humidity = be16_to_cpu(tmp);
+	adc_humidity = get_unaligned_be16(data->buf);
 	if (adc_humidity == BMP280_HUMIDITY_SKIPPED) {
 		/* reading was skipped */
 		dev_err(data->dev, "reading humidity skipped\n");
@@ -755,56 +789,65 @@ static int bmp180_measure(struct bmp280_data *data, u8 ctrl_meas)
 
 static int bmp180_read_adc_temp(struct bmp280_data *data, int *val)
 {
-	__be16 tmp;
 	int ret;
 
 	ret = bmp180_measure(data, BMP180_MEAS_TEMP);
 	if (ret)
 		return ret;
 
-	ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB, &tmp, 2);
+	ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB, data->buf, 2);
 	if (ret)
 		return ret;
 
-	*val = be16_to_cpu(tmp);
+	*val = get_unaligned_be16(data->buf);
 
 	return 0;
 }
 
 static int bmp180_read_calib(struct bmp280_data *data, unsigned int chip)
 {
+	struct bmp180_calib *calib = &data->calib.bmp180;
+	u8 *buf;
 	int ret;
 	int i;
-	struct bmp180_calib *calib = &data->calib.bmp180;
-	__be16 buf[BMP180_REG_CALIB_COUNT / 2];
+
+	buf = kmalloc(BMP180_REG_CALIB_COUNT, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
 
 	ret = regmap_bulk_read(data->regmap, BMP180_REG_CALIB_START, buf,
-			       sizeof(buf));
+			       BMP180_REG_CALIB_COUNT);
 
-	if (ret < 0)
+	if (ret < 0) {
+		kfree(buf);
 		return ret;
+	}
 
 	/* None of the words has the value 0 or 0xFFFF */
-	for (i = 0; i < ARRAY_SIZE(buf); i++) {
-		if (buf[i] == cpu_to_be16(0) || buf[i] == cpu_to_be16(0xffff))
+	for (i = 0; i < BMP180_REG_CALIB_COUNT; i += 2) {
+		if (get_unaligned_be16(&buf[i]) == cpu_to_be16(0) ||
+		    get_unaligned_be16(&buf[i]) == cpu_to_be16(0xffff)) {
+			kfree(buf);
 			return -EIO;
+		}
 	}
 
 	/* Toss the calibration data into the entropy pool */
-	add_device_randomness(buf, sizeof(buf));
-
-	calib->AC1 = be16_to_cpu(buf[AC1]);
-	calib->AC2 = be16_to_cpu(buf[AC2]);
-	calib->AC3 = be16_to_cpu(buf[AC3]);
-	calib->AC4 = be16_to_cpu(buf[AC4]);
-	calib->AC5 = be16_to_cpu(buf[AC5]);
-	calib->AC6 = be16_to_cpu(buf[AC6]);
-	calib->B1 = be16_to_cpu(buf[B1]);
-	calib->B2 = be16_to_cpu(buf[B2]);
-	calib->MB = be16_to_cpu(buf[MB]);
-	calib->MC = be16_to_cpu(buf[MC]);
-	calib->MD = be16_to_cpu(buf[MD]);
-
+	add_device_randomness(buf, BMP180_REG_CALIB_COUNT);
+
+	calib->AC1 = get_unaligned_be16(&buf[AC1]);
+	calib->AC2 = get_unaligned_be16(&buf[AC2]);
+	calib->AC3 = get_unaligned_be16(&buf[AC3]);
+	calib->AC4 = get_unaligned_be16(&buf[AC4]);
+	calib->AC5 = get_unaligned_be16(&buf[AC5]);
+	calib->AC6 = get_unaligned_be16(&buf[AC6]);
+	calib->B1 = get_unaligned_be16(&buf[B1]);
+	calib->B2 = get_unaligned_be16(&buf[B2]);
+	calib->MB = get_unaligned_be16(&buf[MB]);
+	calib->MC = get_unaligned_be16(&buf[MC]);
+	calib->MD = get_unaligned_be16(&buf[MD]);
+
+	kfree(buf);
 	return 0;
 }
 
@@ -852,18 +895,17 @@ static int bmp180_read_temp(struct bmp280_data *data, int *val)
 static int bmp180_read_adc_press(struct bmp280_data *data, int *val)
 {
 	int ret;
-	__be32 tmp = 0;
 	u8 oss = data->oversampling_press;
 
 	ret = bmp180_measure(data, BMP180_MEAS_PRESS_X(oss));
 	if (ret)
 		return ret;
 
-	ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB, &tmp, 3);
+	ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB, data->buf, 3);
 	if (ret)
 		return ret;
 
-	*val = (be32_to_cpu(tmp) >> 8) >> (8 - oss);
+	*val = get_unaligned_be24(data->buf) >> (8 - oss);
 
 	return 0;
 }
-- 
2.37.1

Re: [PATCH v4 3/5] iio: pressure: bmp280: Fix alignment for DMA safety

[Andy Shevchenko]

On Sat, Jul 23, 2022 at 7:40 PM Angel Iglesias <ang.iglesiasg@gmail.com> wrote:
>
> Adds a DMA-safe buffer to driver data struct to store raw data from sensor
>
> Updated calibration read functions to use DMA-safe buffers as well.
> In this case, as calibration data is only read at sensor initialization,
> the buffers are allocated with kmalloc and freed after being processed.

> Suggested-by: Jonathan Cameron <jic23@kernel.org>

Jonathan, maybe it's easier to fix in regmap once for all (something
like a new flag there dma_safe)? Also a side note: i2c doesn't need
that, since it has its own implementation.

P.S. Use sizeof() in regmap calls where it's appropriate.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v4 3/5] iio: pressure: bmp280: Fix alignment for DMA safety

[Jonathan Cameron]

On Mon, 25 Jul 2022 23:08:47 +0200
Andy Shevchenko <andy.shevchenko@gmail.com> wrote:

> On Sat, Jul 23, 2022 at 7:40 PM Angel Iglesias <ang.iglesiasg@gmail.com> wrote:
> >
> > Adds a DMA-safe buffer to driver data struct to store raw data from sensor
> >
> > Updated calibration read functions to use DMA-safe buffers as well.
> > In this case, as calibration data is only read at sensor initialization,
> > the buffers are allocated with kmalloc and freed after being processed.  
> 
> > Suggested-by: Jonathan Cameron <jic23@kernel.org>  
> 
> Jonathan, maybe it's easier to fix in regmap once for all (something
> like a new flag there dma_safe)? Also a side note: i2c doesn't need
> that, since it has its own implementation.

Possibly... Not something I want to tie up with an individual driver though
as it might take a while and be (somewhat) controversial. Nice idea though as, if
a bounce buffer is needed for a particular regmap operation it can implement one
and when not, it can elide that step and just use the provided buffer directly.

Jonathan

> 
> P.S. Use sizeof() in regmap calls where it's appropriate.
> 

Re: [PATCH v4 3/5] iio: pressure: bmp280: Fix alignment for DMA safety

[Jonathan Cameron]

On Sat, 23 Jul 2022 19:39:10 +0200
Angel Iglesias <ang.iglesiasg@gmail.com> wrote:

> Adds a DMA-safe buffer to driver data struct to store raw data from sensor
> 
> Updated calibration read functions to use DMA-safe buffers as well.
> In this case, as calibration data is only read at sensor initialization,
> the buffers are allocated with kmalloc and freed after being processed.
> 
> Suggested-by: Jonathan Cameron <jic23@kernel.org>
> Signed-off-by: Angel Iglesias <ang.iglesiasg@gmail.com>
A few comments inline.  This is more complex than it needs to be because
you can still use __be16 *buf; and index in the right steps.  Side effect
being it's aligned, so conversions will be cheaper as well.

> ---
>  drivers/iio/pressure/bmp280-core.c | 164 ++++++++++++++++++-----------
>  1 file changed, 103 insertions(+), 61 deletions(-)
> 
> diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
> index 60fba199c7a0..9311eeec8473 100644
> --- a/drivers/iio/pressure/bmp280-core.c
> +++ b/drivers/iio/pressure/bmp280-core.c
> @@ -29,6 +29,7 @@
>  #include <linux/completion.h>
>  #include <linux/pm_runtime.h>
>  #include <linux/random.h>
> +#include <asm/unaligned.h>
>  
>  #include "bmp280.h"
>  
> @@ -36,7 +37,19 @@
>   * These enums are used for indexing into the array of calibration
>   * coefficients for BMP180.
>   */
> -enum { AC1, AC2, AC3, AC4, AC5, AC6, B1, B2, MB, MC, MD };
> +enum {
> +	AC1 = 0,
> +	AC2 = 2,
> +	AC3 = 4,
> +	AC4 = 6,
> +	AC5 = 8,
> +	AC6 = 10,
> +	B1 = 12,
> +	B2 = 14,
> +	MB = 16,
> +	MC = 18,
> +	MD = 20,
Looks like we are specifying a size wrong somewhere as these are all 
multiples of 2.

> +};
>  
>  struct bmp180_calib {
>  	s16 AC1;
> @@ -104,6 +117,12 @@ struct bmp280_data {
>  	 * calculation.
>  	 */
>  	s32 t_fine;
> +
> +	/*
> +	 * DMA (thus cache coherency maintenance) may require the
> +	 * transfer buffers to live in their own cache lines.
> +	 */
> +	u8 buf[3] __aligned(IIO_DMA_MINALIGN);
So, on many platforms of interest (anything arm64) we are going to be
padding this struture out after this to 128 bytes anyway.  So no advantage
to keeping this short.  I'd just use this buffer for the calibration cases
as well and drop the extra allocations.  You'll waste space on x86/x86_64 but
meh, who cares about those legacy architectures :)


>  };
>  
>  struct bmp280_chip_info {
> @@ -135,8 +154,18 @@ struct bmp280_chip_info {
>   * These enums are used for indexing into the array of compensation
>   * parameters for BMP280.
>   */
> -enum { T1, T2, T3 };
> -enum { P1, P2, P3, P4, P5, P6, P7, P8, P9 };
> +enum { T1 = 0, T2 = 2, T3 = 4 };
> +enum {
> +	P1 = 0,
> +	P2 = 2,
> +	P3 = 4,
> +	P4 = 6,
> +	P5 = 8,
> +	P6 = 10,
> +	P7 = 12,
> +	P8 = 14,
> +	P9 = 16,
> +};
>  
>  static const struct iio_chan_spec bmp280_channels[] = {
>  	{
> @@ -159,51 +188,59 @@ static const struct iio_chan_spec bmp280_channels[] = {
>  static int bmp280_read_calib(struct bmp280_data *data, unsigned int chip)
>  {
>  	int ret;
> +	u8 *t_buf;
> +	u8 *p_buf;
>  	unsigned int tmp;
> -	__le16 l16;
> -	__be16 b16;
>  	struct device *dev = data->dev;
>  	struct bmp280_calib *calib = &data->calib.bmp280;
> -	__le16 t_buf[BMP280_COMP_TEMP_REG_COUNT / 2];
> -	__le16 p_buf[BMP280_COMP_PRESS_REG_COUNT / 2];
>  
> +	t_buf = kmalloc(BMP280_COMP_TEMP_REG_COUNT, GFP_KERNEL);
> +	if (!t_buf)
> +		return -ENOMEM;
>  	/* Read temperature calibration values. */
>  	ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_TEMP_START,
>  			       t_buf, BMP280_COMP_TEMP_REG_COUNT);
>  	if (ret < 0) {
>  		dev_err(data->dev,
>  			"failed to read temperature calibration parameters\n");
> +		kfree(t_buf);
>  		return ret;
>  	}
>  
>  	/* Toss the temperature calibration data into the entropy pool */
>  	add_device_randomness(t_buf, sizeof(t_buf));
>  
> -	calib->T1 = le16_to_cpu(t_buf[T1]);
> -	calib->T2 = le16_to_cpu(t_buf[T2]);
> -	calib->T3 = le16_to_cpu(t_buf[T3]);
> +	calib->T1 = get_unaligned_le16(&t_buf[T1]);
> +	calib->T2 = get_unaligned_le16(&t_buf[T2]);
> +	calib->T3 = get_unaligned_le16(&t_buf[T3]);
> +	kfree(t_buf);
>  
> +	p_buf = kmalloc(BMP280_COMP_PRESS_REG_COUNT, GFP_KERNEL);
> +	if (!p_buf)
> +		return -ENOMEM;
>  	/* Read pressure calibration values. */
>  	ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_PRESS_START,
>  			       p_buf, BMP280_COMP_PRESS_REG_COUNT);
>  	if (ret < 0) {
>  		dev_err(data->dev,
>  			"failed to read pressure calibration parameters\n");
> +		kfree(p_buf);
>  		return ret;
>  	}
>  
>  	/* Toss the pressure calibration data into the entropy pool */
>  	add_device_randomness(p_buf, sizeof(p_buf));
>  
> -	calib->P1 = le16_to_cpu(p_buf[P1]);
> -	calib->P2 = le16_to_cpu(p_buf[P2]);
> -	calib->P3 = le16_to_cpu(p_buf[P3]);
> -	calib->P4 = le16_to_cpu(p_buf[P4]);
> -	calib->P5 = le16_to_cpu(p_buf[P5]);
> -	calib->P6 = le16_to_cpu(p_buf[P6]);
> -	calib->P7 = le16_to_cpu(p_buf[P7]);
> -	calib->P8 = le16_to_cpu(p_buf[P8]);
> -	calib->P9 = le16_to_cpu(p_buf[P9]);
> +	calib->P1 = get_unaligned_le16(&p_buf[P1]);
> +	calib->P2 = get_unaligned_le16(&p_buf[P2]);
> +	calib->P3 = get_unaligned_le16(&p_buf[P3]);
> +	calib->P4 = get_unaligned_le16(&p_buf[P4]);
> +	calib->P5 = get_unaligned_le16(&p_buf[P5]);
> +	calib->P6 = get_unaligned_le16(&p_buf[P6]);
> +	calib->P7 = get_unaligned_le16(&p_buf[P7]);
> +	calib->P8 = get_unaligned_le16(&p_buf[P8]);
> +	calib->P9 = get_unaligned_le16(&p_buf[P9]);
> +	kfree(p_buf);
>  
>  	/*
>  	 * Read humidity calibration values.
> @@ -222,12 +259,12 @@ static int bmp280_read_calib(struct bmp280_data *data, unsigned int chip)
>  	}
>  	calib->H1 = tmp;
>  
> -	ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H2, &l16, 2);
> +	ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H2, data->buf, 2);
>  	if (ret < 0) {
>  		dev_err(dev, "failed to read H2 comp value\n");
>  		return ret;
>  	}
> -	calib->H2 = sign_extend32(le16_to_cpu(l16), 15);
> +	calib->H2 = get_unaligned_le16(data->buf);
>  
>  	ret = regmap_read(data->regmap, BMP280_REG_COMP_H3, &tmp);
>  	if (ret < 0) {
> @@ -236,20 +273,20 @@ static int bmp280_read_calib(struct bmp280_data *data, unsigned int chip)
>  	}
>  	calib->H3 = tmp;
>  
> -	ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H4, &b16, 2);
> +	ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H4, data->buf, 2);
>  	if (ret < 0) {
>  		dev_err(dev, "failed to read H4 comp value\n");
>  		return ret;
>  	}
> -	calib->H4 = sign_extend32(((be16_to_cpu(b16) >> 4) & 0xff0) |
> -				  (be16_to_cpu(b16) & 0xf), 11);
> +	calib->H4 = sign_extend32(((get_unaligned_be16(data->buf) >> 4) & 0xff0) |
> +				  (get_unaligned_be16(data->buf) & 0xf), 11);
>  
> -	ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H5, &l16, 2);
> +	ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H5, data->buf, 2);
>  	if (ret < 0) {
>  		dev_err(dev, "failed to read H5 comp value\n");
>  		return ret;
>  	}
> -	calib->H5 = sign_extend32(((le16_to_cpu(l16) >> 4) & 0xfff), 11);
> +	calib->H5 = sign_extend32(((get_unaligned_le16(data->buf) >> 4) & 0xfff), 11);
>  
>  	ret = regmap_read(data->regmap, BMP280_REG_COMP_H6, &tmp);
>  	if (ret < 0) {
> @@ -344,16 +381,15 @@ static int bmp280_read_temp(struct bmp280_data *data,
>  			    int *val)
>  {
>  	int ret;
> -	__be32 tmp = 0;
>  	s32 adc_temp, comp_temp;
>  
> -	ret = regmap_bulk_read(data->regmap, BMP280_REG_TEMP_MSB, &tmp, 3);
> +	ret = regmap_bulk_read(data->regmap, BMP280_REG_TEMP_MSB, data->buf, 3);
>  	if (ret < 0) {
>  		dev_err(data->dev, "failed to read temperature\n");
>  		return ret;
>  	}
>  
> -	adc_temp = be32_to_cpu(tmp) >> 12;
> +	adc_temp = get_unaligned_be24(data->buf) >> 4;
>  	if (adc_temp == BMP280_TEMP_SKIPPED) {
>  		/* reading was skipped */
>  		dev_err(data->dev, "reading temperature skipped\n");
> @@ -377,7 +413,6 @@ static int bmp280_read_press(struct bmp280_data *data,
>  			     int *val, int *val2)
>  {
>  	int ret;
> -	__be32 tmp = 0;
>  	s32 adc_press;
>  	u32 comp_press;
>  
> @@ -386,13 +421,13 @@ static int bmp280_read_press(struct bmp280_data *data,
>  	if (ret < 0)
>  		return ret;
>  
> -	ret = regmap_bulk_read(data->regmap, BMP280_REG_PRESS_MSB, &tmp, 3);
> +	ret = regmap_bulk_read(data->regmap, BMP280_REG_PRESS_MSB, data->buf, 3);
>  	if (ret < 0) {
>  		dev_err(data->dev, "failed to read pressure\n");
>  		return ret;
>  	}
>  
> -	adc_press = be32_to_cpu(tmp) >> 12;
> +	adc_press = get_unaligned_be24(data->buf) >> 4;
>  	if (adc_press == BMP280_PRESS_SKIPPED) {
>  		/* reading was skipped */
>  		dev_err(data->dev, "reading pressure skipped\n");
> @@ -408,7 +443,6 @@ static int bmp280_read_press(struct bmp280_data *data,
>  
>  static int bmp280_read_humid(struct bmp280_data *data, int *val, int *val2)
>  {
> -	__be16 tmp;
>  	int ret;
>  	s32 adc_humidity;
>  	u32 comp_humidity;
> @@ -418,13 +452,13 @@ static int bmp280_read_humid(struct bmp280_data *data, int *val, int *val2)
>  	if (ret < 0)
>  		return ret;
>  
> -	ret = regmap_bulk_read(data->regmap, BMP280_REG_HUMIDITY_MSB, &tmp, 2);
> +	ret = regmap_bulk_read(data->regmap, BMP280_REG_HUMIDITY_MSB, data->buf, 2);
>  	if (ret < 0) {
>  		dev_err(data->dev, "failed to read humidity\n");
>  		return ret;
>  	}
>  
> -	adc_humidity = be16_to_cpu(tmp);
> +	adc_humidity = get_unaligned_be16(data->buf);
>  	if (adc_humidity == BMP280_HUMIDITY_SKIPPED) {
>  		/* reading was skipped */
>  		dev_err(data->dev, "reading humidity skipped\n");
> @@ -755,56 +789,65 @@ static int bmp180_measure(struct bmp280_data *data, u8 ctrl_meas)
>  
>  static int bmp180_read_adc_temp(struct bmp280_data *data, int *val)
>  {
> -	__be16 tmp;
>  	int ret;
>  
>  	ret = bmp180_measure(data, BMP180_MEAS_TEMP);
>  	if (ret)
>  		return ret;
>  
> -	ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB, &tmp, 2);
> +	ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB, data->buf, 2);
>  	if (ret)
>  		return ret;
>  
> -	*val = be16_to_cpu(tmp);
> +	*val = get_unaligned_be16(data->buf);
>  
>  	return 0;
>  }
>  
>  static int bmp180_read_calib(struct bmp280_data *data, unsigned int chip)
>  {
> +	struct bmp180_calib *calib = &data->calib.bmp180;
> +	u8 *buf;
>  	int ret;
>  	int i;
> -	struct bmp180_calib *calib = &data->calib.bmp180;
> -	__be16 buf[BMP180_REG_CALIB_COUNT / 2];
> +
> +	buf = kmalloc(BMP180_REG_CALIB_COUNT, GFP_KERNEL);
No need to change the type of buf.  Keep it as __be16 *buf = kmalloc()...
That way your indexing still works nicely without needing to scatter *2 and += 2
throughout.  Note that if you embed this as I suggest above, just use a union so
you can overlap it with the u8 buffer.

> +	if (!buf)
> +		return -ENOMEM;
>  
>  	ret = regmap_bulk_read(data->regmap, BMP180_REG_CALIB_START, buf,
> -			       sizeof(buf));
> +			       BMP180_REG_CALIB_COUNT);
>  
> -	if (ret < 0)
> +	if (ret < 0) {
> +		kfree(buf);
>  		return ret;
> +	}
>  
>  	/* None of the words has the value 0 or 0xFFFF */
> -	for (i = 0; i < ARRAY_SIZE(buf); i++) {
> -		if (buf[i] == cpu_to_be16(0) || buf[i] == cpu_to_be16(0xffff))
> +	for (i = 0; i < BMP180_REG_CALIB_COUNT; i += 2) {
> +		if (get_unaligned_be16(&buf[i]) == cpu_to_be16(0) ||
> +		    get_unaligned_be16(&buf[i]) == cpu_to_be16(0xffff)) {
> +			kfree(buf);
>  			return -EIO;
> +		}
>  	}
>  
>  	/* Toss the calibration data into the entropy pool */
> -	add_device_randomness(buf, sizeof(buf));
> -
> -	calib->AC1 = be16_to_cpu(buf[AC1]);
> -	calib->AC2 = be16_to_cpu(buf[AC2]);
> -	calib->AC3 = be16_to_cpu(buf[AC3]);
> -	calib->AC4 = be16_to_cpu(buf[AC4]);
> -	calib->AC5 = be16_to_cpu(buf[AC5]);
> -	calib->AC6 = be16_to_cpu(buf[AC6]);
> -	calib->B1 = be16_to_cpu(buf[B1]);
> -	calib->B2 = be16_to_cpu(buf[B2]);
> -	calib->MB = be16_to_cpu(buf[MB]);
> -	calib->MC = be16_to_cpu(buf[MC]);
> -	calib->MD = be16_to_cpu(buf[MD]);
> -
> +	add_device_randomness(buf, BMP180_REG_CALIB_COUNT);
> +
> +	calib->AC1 = get_unaligned_be16(&buf[AC1]);
> +	calib->AC2 = get_unaligned_be16(&buf[AC2]);
> +	calib->AC3 = get_unaligned_be16(&buf[AC3]);
> +	calib->AC4 = get_unaligned_be16(&buf[AC4]);
> +	calib->AC5 = get_unaligned_be16(&buf[AC5]);
> +	calib->AC6 = get_unaligned_be16(&buf[AC6]);
> +	calib->B1 = get_unaligned_be16(&buf[B1]);
> +	calib->B2 = get_unaligned_be16(&buf[B2]);
> +	calib->MB = get_unaligned_be16(&buf[MB]);
> +	calib->MC = get_unaligned_be16(&buf[MC]);
> +	calib->MD = get_unaligned_be16(&buf[MD]);
> +
> +	kfree(buf);
>  	return 0;
>  }
>  
> @@ -852,18 +895,17 @@ static int bmp180_read_temp(struct bmp280_data *data, int *val)
>  static int bmp180_read_adc_press(struct bmp280_data *data, int *val)
>  {
>  	int ret;
> -	__be32 tmp = 0;
>  	u8 oss = data->oversampling_press;
>  
>  	ret = bmp180_measure(data, BMP180_MEAS_PRESS_X(oss));
>  	if (ret)
>  		return ret;
>  
> -	ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB, &tmp, 3);
> +	ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB, data->buf, 3);
>  	if (ret)
>  		return ret;
>  
> -	*val = (be32_to_cpu(tmp) >> 8) >> (8 - oss);
> +	*val = get_unaligned_be24(data->buf) >> (8 - oss);
>  
>  	return 0;
>  }

Re: [PATCH v4 3/5] iio: pressure: bmp280: Fix alignment for DMA safety

[Angel Iglesias]

On dom, 2022-07-31 at 17:13 +0100, Jonathan Cameron wrote:
> On Sat, 23 Jul 2022 19:39:10 +0200
> Angel Iglesias <ang.iglesiasg@gmail.com> wrote:
> 
> > Adds a DMA-safe buffer to driver data struct to store raw data from sensor
> > 
> > Updated calibration read functions to use DMA-safe buffers as well.
> > In this case, as calibration data is only read at sensor initialization,
> > the buffers are allocated with kmalloc and freed after being processed.
> > 
> > Suggested-by: Jonathan Cameron <jic23@kernel.org>
> > Signed-off-by: Angel Iglesias <ang.iglesiasg@gmail.com>
> A few comments inline.  This is more complex than it needs to be because
> you can still use __be16 *buf; and index in the right steps.  Side effect
> being it's aligned, so conversions will be cheaper as well.
> 
> > ---
> >  drivers/iio/pressure/bmp280-core.c | 164 ++++++++++++++++++-----------
> >  1 file changed, 103 insertions(+), 61 deletions(-)
> > 
> > diff --git a/drivers/iio/pressure/bmp280-core.c
> > b/drivers/iio/pressure/bmp280-core.c
> > index 60fba199c7a0..9311eeec8473 100644
> > --- a/drivers/iio/pressure/bmp280-core.c
> > +++ b/drivers/iio/pressure/bmp280-core.c
> > @@ -29,6 +29,7 @@
> >  #include <linux/completion.h>
> >  #include <linux/pm_runtime.h>
> >  #include <linux/random.h>
> > +#include <asm/unaligned.h>
> >  
> >  #include "bmp280.h"
> >  
> > @@ -36,7 +37,19 @@
> >   * These enums are used for indexing into the array of calibration
> >   * coefficients for BMP180.
> >   */
> > -enum { AC1, AC2, AC3, AC4, AC5, AC6, B1, B2, MB, MC, MD };
> > +enum {
> > +       AC1 = 0,
> > +       AC2 = 2,
> > +       AC3 = 4,
> > +       AC4 = 6,
> > +       AC5 = 8,
> > +       AC6 = 10,
> > +       B1 = 12,
> > +       B2 = 14,
> > +       MB = 16,
> > +       MC = 18,
> > +       MD = 20,
> Looks like we are specifying a size wrong somewhere as these are all 
> multiples of 2.
> 
> > +};
> >  
> >  struct bmp180_calib {
> >         s16 AC1;
> > @@ -104,6 +117,12 @@ struct bmp280_data {
> >          * calculation.
> >          */
> >         s32 t_fine;
> > +
> > +       /*
> > +        * DMA (thus cache coherency maintenance) may require the
> > +        * transfer buffers to live in their own cache lines.
> > +        */
> > +       u8 buf[3] __aligned(IIO_DMA_MINALIGN);
> So, on many platforms of interest (anything arm64) we are going to be
> padding this struture out after this to 128 bytes anyway.  So no advantage
> to keeping this short.  I'd just use this buffer for the calibration cases
> as well and drop the extra allocations.  You'll waste space on x86/x86_64 but
> meh, who cares about those legacy architectures :)

Oh I see, I tried to save memory only using this 3 bytes to read the adcs raw
values from the sensors and allocating dynamically the buffers to read
calibration values and ended wasting more memory :(
Thanks for the insight, I'll do my homework and study in more detail DMA and
memory allocation in this platforms.

Yes, this will probably end running on fancier archs like arm64 or risc-v :)
(I'm using a couple of arm64 boards to test the sensors)

> >  };
> >  
> >  struct bmp280_chip_info {
> > @@ -135,8 +154,18 @@ struct bmp280_chip_info {
> >   * These enums are used for indexing into the array of compensation
> >   * parameters for BMP280.
> >   */
> > -enum { T1, T2, T3 };
> > -enum { P1, P2, P3, P4, P5, P6, P7, P8, P9 };
> > +enum { T1 = 0, T2 = 2, T3 = 4 };
> > +enum {
> > +       P1 = 0,
> > +       P2 = 2,
> > +       P3 = 4,
> > +       P4 = 6,
> > +       P5 = 8,
> > +       P6 = 10,
> > +       P7 = 12,
> > +       P8 = 14,
> > +       P9 = 16,
> > +};
> >  
> >  static const struct iio_chan_spec bmp280_channels[] = {
> >         {
> > @@ -159,51 +188,59 @@ static const struct iio_chan_spec bmp280_channels[] =
> > {
> >  static int bmp280_read_calib(struct bmp280_data *data, unsigned int chip)
> >  {
> >         int ret;
> > +       u8 *t_buf;
> > +       u8 *p_buf;
> >         unsigned int tmp;
> > -       __le16 l16;
> > -       __be16 b16;
> >         struct device *dev = data->dev;
> >         struct bmp280_calib *calib = &data->calib.bmp280;
> > -       __le16 t_buf[BMP280_COMP_TEMP_REG_COUNT / 2];
> > -       __le16 p_buf[BMP280_COMP_PRESS_REG_COUNT / 2];
> >  
> > +       t_buf = kmalloc(BMP280_COMP_TEMP_REG_COUNT, GFP_KERNEL);
> > +       if (!t_buf)
> > +               return -ENOMEM;
> >         /* Read temperature calibration values. */
> >         ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_TEMP_START,
> >                                t_buf, BMP280_COMP_TEMP_REG_COUNT);
> >         if (ret < 0) {
> >                 dev_err(data->dev,
> >                         "failed to read temperature calibration
> > parameters\n");
> > +               kfree(t_buf);
> >                 return ret;
> >         }
> >  
> >         /* Toss the temperature calibration data into the entropy pool */
> >         add_device_randomness(t_buf, sizeof(t_buf));
> >  
> > -       calib->T1 = le16_to_cpu(t_buf[T1]);
> > -       calib->T2 = le16_to_cpu(t_buf[T2]);
> > -       calib->T3 = le16_to_cpu(t_buf[T3]);
> > +       calib->T1 = get_unaligned_le16(&t_buf[T1]);
> > +       calib->T2 = get_unaligned_le16(&t_buf[T2]);
> > +       calib->T3 = get_unaligned_le16(&t_buf[T3]);
> > +       kfree(t_buf);
> >  
> > +       p_buf = kmalloc(BMP280_COMP_PRESS_REG_COUNT, GFP_KERNEL);
> > +       if (!p_buf)
> > +               return -ENOMEM;
> >         /* Read pressure calibration values. */
> >         ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_PRESS_START,
> >                                p_buf, BMP280_COMP_PRESS_REG_COUNT);
> >         if (ret < 0) {
> >                 dev_err(data->dev,
> >                         "failed to read pressure calibration parameters\n");
> > +               kfree(p_buf);
> >                 return ret;
> >         }
> >  
> >         /* Toss the pressure calibration data into the entropy pool */
> >         add_device_randomness(p_buf, sizeof(p_buf));
> >  
> > -       calib->P1 = le16_to_cpu(p_buf[P1]);
> > -       calib->P2 = le16_to_cpu(p_buf[P2]);
> > -       calib->P3 = le16_to_cpu(p_buf[P3]);
> > -       calib->P4 = le16_to_cpu(p_buf[P4]);
> > -       calib->P5 = le16_to_cpu(p_buf[P5]);
> > -       calib->P6 = le16_to_cpu(p_buf[P6]);
> > -       calib->P7 = le16_to_cpu(p_buf[P7]);
> > -       calib->P8 = le16_to_cpu(p_buf[P8]);
> > -       calib->P9 = le16_to_cpu(p_buf[P9]);
> > +       calib->P1 = get_unaligned_le16(&p_buf[P1]);
> > +       calib->P2 = get_unaligned_le16(&p_buf[P2]);
> > +       calib->P3 = get_unaligned_le16(&p_buf[P3]);
> > +       calib->P4 = get_unaligned_le16(&p_buf[P4]);
> > +       calib->P5 = get_unaligned_le16(&p_buf[P5]);
> > +       calib->P6 = get_unaligned_le16(&p_buf[P6]);
> > +       calib->P7 = get_unaligned_le16(&p_buf[P7]);
> > +       calib->P8 = get_unaligned_le16(&p_buf[P8]);
> > +       calib->P9 = get_unaligned_le16(&p_buf[P9]);
> > +       kfree(p_buf);
> >  
> >         /*
> >          * Read humidity calibration values.
> > @@ -222,12 +259,12 @@ static int bmp280_read_calib(struct bmp280_data *data,
> > unsigned int chip)
> >         }
> >         calib->H1 = tmp;
> >  
> > -       ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H2, &l16, 2);
> > +       ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H2, data->buf,
> > 2);
> >         if (ret < 0) {
> >                 dev_err(dev, "failed to read H2 comp value\n");
> >                 return ret;
> >         }
> > -       calib->H2 = sign_extend32(le16_to_cpu(l16), 15);
> > +       calib->H2 = get_unaligned_le16(data->buf);
> >  
> >         ret = regmap_read(data->regmap, BMP280_REG_COMP_H3, &tmp);
> >         if (ret < 0) {
> > @@ -236,20 +273,20 @@ static int bmp280_read_calib(struct bmp280_data *data,
> > unsigned int chip)
> >         }
> >         calib->H3 = tmp;
> >  
> > -       ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H4, &b16, 2);
> > +       ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H4, data->buf,
> > 2);
> >         if (ret < 0) {
> >                 dev_err(dev, "failed to read H4 comp value\n");
> >                 return ret;
> >         }
> > -       calib->H4 = sign_extend32(((be16_to_cpu(b16) >> 4) & 0xff0) |
> > -                                 (be16_to_cpu(b16) & 0xf), 11);
> > +       calib->H4 = sign_extend32(((get_unaligned_be16(data->buf) >> 4) &
> > 0xff0) |
> > +                                 (get_unaligned_be16(data->buf) & 0xf),
> > 11);
> >  
> > -       ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H5, &l16, 2);
> > +       ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H5, data->buf,
> > 2);
> >         if (ret < 0) {
> >                 dev_err(dev, "failed to read H5 comp value\n");
> >                 return ret;
> >         }
> > -       calib->H5 = sign_extend32(((le16_to_cpu(l16) >> 4) & 0xfff), 11);
> > +       calib->H5 = sign_extend32(((get_unaligned_le16(data->buf) >> 4) &
> > 0xfff), 11);
> >  
> >         ret = regmap_read(data->regmap, BMP280_REG_COMP_H6, &tmp);
> >         if (ret < 0) {
> > @@ -344,16 +381,15 @@ static int bmp280_read_temp(struct bmp280_data *data,
> >                             int *val)
> >  {
> >         int ret;
> > -       __be32 tmp = 0;
> >         s32 adc_temp, comp_temp;
> >  
> > -       ret = regmap_bulk_read(data->regmap, BMP280_REG_TEMP_MSB, &tmp, 3);
> > +       ret = regmap_bulk_read(data->regmap, BMP280_REG_TEMP_MSB, data->buf,
> > 3);
> >         if (ret < 0) {
> >                 dev_err(data->dev, "failed to read temperature\n");
> >                 return ret;
> >         }
> >  
> > -       adc_temp = be32_to_cpu(tmp) >> 12;
> > +       adc_temp = get_unaligned_be24(data->buf) >> 4;
> >         if (adc_temp == BMP280_TEMP_SKIPPED) {
> >                 /* reading was skipped */
> >                 dev_err(data->dev, "reading temperature skipped\n");
> > @@ -377,7 +413,6 @@ static int bmp280_read_press(struct bmp280_data *data,
> >                              int *val, int *val2)
> >  {
> >         int ret;
> > -       __be32 tmp = 0;
> >         s32 adc_press;
> >         u32 comp_press;
> >  
> > @@ -386,13 +421,13 @@ static int bmp280_read_press(struct bmp280_data *data,
> >         if (ret < 0)
> >                 return ret;
> >  
> > -       ret = regmap_bulk_read(data->regmap, BMP280_REG_PRESS_MSB, &tmp, 3);
> > +       ret = regmap_bulk_read(data->regmap, BMP280_REG_PRESS_MSB, data-
> > >buf, 3);
> >         if (ret < 0) {
> >                 dev_err(data->dev, "failed to read pressure\n");
> >                 return ret;
> >         }
> >  
> > -       adc_press = be32_to_cpu(tmp) >> 12;
> > +       adc_press = get_unaligned_be24(data->buf) >> 4;
> >         if (adc_press == BMP280_PRESS_SKIPPED) {
> >                 /* reading was skipped */
> >                 dev_err(data->dev, "reading pressure skipped\n");
> > @@ -408,7 +443,6 @@ static int bmp280_read_press(struct bmp280_data *data,
> >  
> >  static int bmp280_read_humid(struct bmp280_data *data, int *val, int *val2)
> >  {
> > -       __be16 tmp;
> >         int ret;
> >         s32 adc_humidity;
> >         u32 comp_humidity;
> > @@ -418,13 +452,13 @@ static int bmp280_read_humid(struct bmp280_data *data,
> > int *val, int *val2)
> >         if (ret < 0)
> >                 return ret;
> >  
> > -       ret = regmap_bulk_read(data->regmap, BMP280_REG_HUMIDITY_MSB, &tmp,
> > 2);
> > +       ret = regmap_bulk_read(data->regmap, BMP280_REG_HUMIDITY_MSB, data-
> > >buf, 2);
> >         if (ret < 0) {
> >                 dev_err(data->dev, "failed to read humidity\n");
> >                 return ret;
> >         }
> >  
> > -       adc_humidity = be16_to_cpu(tmp);
> > +       adc_humidity = get_unaligned_be16(data->buf);
> >         if (adc_humidity == BMP280_HUMIDITY_SKIPPED) {
> >                 /* reading was skipped */
> >                 dev_err(data->dev, "reading humidity skipped\n");
> > @@ -755,56 +789,65 @@ static int bmp180_measure(struct bmp280_data *data, u8
> > ctrl_meas)
> >  
> >  static int bmp180_read_adc_temp(struct bmp280_data *data, int *val)
> >  {
> > -       __be16 tmp;
> >         int ret;
> >  
> >         ret = bmp180_measure(data, BMP180_MEAS_TEMP);
> >         if (ret)
> >                 return ret;
> >  
> > -       ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB, &tmp, 2);
> > +       ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB, data->buf,
> > 2);
> >         if (ret)
> >                 return ret;
> >  
> > -       *val = be16_to_cpu(tmp);
> > +       *val = get_unaligned_be16(data->buf);
> >  
> >         return 0;
> >  }
> >  
> >  static int bmp180_read_calib(struct bmp280_data *data, unsigned int chip)
> >  {
> > +       struct bmp180_calib *calib = &data->calib.bmp180;
> > +       u8 *buf;
> >         int ret;
> >         int i;
> > -       struct bmp180_calib *calib = &data->calib.bmp180;
> > -       __be16 buf[BMP180_REG_CALIB_COUNT / 2];
> > +
> > +       buf = kmalloc(BMP180_REG_CALIB_COUNT, GFP_KERNEL);
> No need to change the type of buf.  Keep it as __be16 *buf = kmalloc()...
> That way your indexing still works nicely without needing to scatter *2 and +=
> 2
> throughout.  Note that if you embed this as I suggest above, just use a union
> so
> you can overlap it with the u8 buffer.
> 
> > +       if (!buf)
> > +               return -ENOMEM;
> >  
> >         ret = regmap_bulk_read(data->regmap, BMP180_REG_CALIB_START, buf,
> > -                              sizeof(buf));
> > +                              BMP180_REG_CALIB_COUNT);
> >  
> > -       if (ret < 0)
> > +       if (ret < 0) {
> > +               kfree(buf);
> >                 return ret;
> > +       }
> >  
> >         /* None of the words has the value 0 or 0xFFFF */
> > -       for (i = 0; i < ARRAY_SIZE(buf); i++) {
> > -               if (buf[i] == cpu_to_be16(0) || buf[i] ==
> > cpu_to_be16(0xffff))
> > +       for (i = 0; i < BMP180_REG_CALIB_COUNT; i += 2) {
> > +               if (get_unaligned_be16(&buf[i]) == cpu_to_be16(0) ||
> > +                   get_unaligned_be16(&buf[i]) == cpu_to_be16(0xffff)) {
> > +                       kfree(buf);
> >                         return -EIO;
> > +               }
> >         }
> >  
> >         /* Toss the calibration data into the entropy pool */
> > -       add_device_randomness(buf, sizeof(buf));
> > -
> > -       calib->AC1 = be16_to_cpu(buf[AC1]);
> > -       calib->AC2 = be16_to_cpu(buf[AC2]);
> > -       calib->AC3 = be16_to_cpu(buf[AC3]);
> > -       calib->AC4 = be16_to_cpu(buf[AC4]);
> > -       calib->AC5 = be16_to_cpu(buf[AC5]);
> > -       calib->AC6 = be16_to_cpu(buf[AC6]);
> > -       calib->B1 = be16_to_cpu(buf[B1]);
> > -       calib->B2 = be16_to_cpu(buf[B2]);
> > -       calib->MB = be16_to_cpu(buf[MB]);
> > -       calib->MC = be16_to_cpu(buf[MC]);
> > -       calib->MD = be16_to_cpu(buf[MD]);
> > -
> > +       add_device_randomness(buf, BMP180_REG_CALIB_COUNT);
> > +
> > +       calib->AC1 = get_unaligned_be16(&buf[AC1]);
> > +       calib->AC2 = get_unaligned_be16(&buf[AC2]);
> > +       calib->AC3 = get_unaligned_be16(&buf[AC3]);
> > +       calib->AC4 = get_unaligned_be16(&buf[AC4]);
> > +       calib->AC5 = get_unaligned_be16(&buf[AC5]);
> > +       calib->AC6 = get_unaligned_be16(&buf[AC6]);
> > +       calib->B1 = get_unaligned_be16(&buf[B1]);
> > +       calib->B2 = get_unaligned_be16(&buf[B2]);
> > +       calib->MB = get_unaligned_be16(&buf[MB]);
> > +       calib->MC = get_unaligned_be16(&buf[MC]);
> > +       calib->MD = get_unaligned_be16(&buf[MD]);
> > +
> > +       kfree(buf);
> >         return 0;
> >  }
> >  
> > @@ -852,18 +895,17 @@ static int bmp180_read_temp(struct bmp280_data *data,
> > int *val)
> >  static int bmp180_read_adc_press(struct bmp280_data *data, int *val)
> >  {
> >         int ret;
> > -       __be32 tmp = 0;
> >         u8 oss = data->oversampling_press;
> >  
> >         ret = bmp180_measure(data, BMP180_MEAS_PRESS_X(oss));
> >         if (ret)
> >                 return ret;
> >  
> > -       ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB, &tmp, 3);
> > +       ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB, data->buf,
> > 3);
> >         if (ret)
> >                 return ret;
> >  
> > -       *val = (be32_to_cpu(tmp) >> 8) >> (8 - oss);
> > +       *val = get_unaligned_be24(data->buf) >> (8 - oss);
> >  
> >         return 0;
> >  }
> 

As always, thanks for your comments,

Kind regards,
Angel

[PATCH v4 4/5] iio: pressure: bmp280: Add support for BMP380 sensor family

[Angel Iglesias]

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@gmail.com>
---
 drivers/iio/pressure/Kconfig         |   6 +-
 drivers/iio/pressure/bmp280-core.c   | 359 +++++++++++++++++++++++++++
 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 ++++++++
 6 files changed, 528 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/pressure/Kconfig b/drivers/iio/pressure/Kconfig
index 0ff756cea63a..c9453389e4f7 100644
--- a/drivers/iio/pressure/Kconfig
+++ b/drivers/iio/pressure/Kconfig
@@ -17,14 +17,14 @@ config ABP060MG
 	  will be called abp060mg.
 
 config BMP280
-	tristate "Bosch Sensortec BMP180/BMP280 pressure sensor I2C driver"
+	tristate "Bosch Sensortec BMP180/BMP280/BMP380 pressure sensor I2C driver"
 	depends on (I2C || SPI_MASTER)
 	select REGMAP
 	select BMP280_I2C if (I2C)
 	select BMP280_SPI if (SPI_MASTER)
 	help
-	  Say yes here to build support for Bosch Sensortec BMP180 and BMP280
-	  pressure and temperature sensors. Also supports the BME280 with
+	  Say yes here to build support for Bosch Sensortec BMP180, BMP280 and
+	  BMP380 pressure and temperature sensors. Also supports the BME280 with
 	  an additional humidity sensor channel.
 
 	  To compile this driver as a module, choose M here: the core module
diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
index 9311eeec8473..f5b1344b8e20 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>
@@ -87,6 +90,24 @@ 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"
 };
@@ -103,6 +124,7 @@ 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 */
@@ -167,6 +189,25 @@ enum {
 	P9 = 16,
 };
 
+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,
@@ -742,6 +783,314 @@ 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, &reg);
+	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, &reg);
+	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;
+	u32 adc_temp;
+	s32 comp_temp;
+
+	ret = regmap_bulk_read(data->regmap, BMP380_REG_TEMP_XLSB, data->buf, 3);
+	if (ret < 0) {
+		dev_err(data->dev, "failed to read temperature\n");
+		return ret;
+	}
+
+	adc_temp = get_unaligned_le24(data->buf);
+	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;
+	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, data->buf, 3);
+	if (ret < 0) {
+		dev_err(data->dev, "failed to read pressure\n");
+		return ret;
+	}
+
+	adc_press = get_unaligned_le24(data->buf);
+	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)
+{
+	struct bmp380_calib *calib = &data->calib.bmp380;
+	int ret;
+	u8 *buf;
+
+	buf = kmalloc(BMP380_CALIB_REG_COUNT, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	/* 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");
+		kfree(buf);
+		return ret;
+	}
+
+	/* Toss the temperature calibration data into the entropy pool */
+	add_device_randomness(buf, BMP380_CALIB_REG_COUNT);
+
+	/* 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];
+
+	kfree(buf);
+	return 0;
+}
+
+static int bmp380_chip_config(struct bmp280_data *data)
+{
+	unsigned int tmp;
+	u8 osrs;
+	int ret;
+
+	/* configure power control register */
+	ret = regmap_write_bits(data->regmap, BMP380_REG_POWER_CONTROL,
+				BMP380_CTRL_SENSORS_MASK | BMP380_MODE_MASK,
+				BMP380_CTRL_SENSORS_PRESS_EN |
+				BMP380_CTRL_SENSORS_TEMP_EN |
+				FIELD_PREP(BMP380_MODE_MASK, BMP380_MODE_NORMAL));
+	if (ret < 0) {
+		dev_err(data->dev,
+			"failed to write operation control register\n");
+		return ret;
+	}
+
+	/* configure oversampling */
+	osrs = FIELD_PREP(BMP380_OSRS_TEMP_MASK, data->oversampling_temp) |
+	       FIELD_PREP(BMP380_OSRS_PRESS_MASK, data->oversampling_press);
+
+	ret = regmap_write_bits(data->regmap, BMP380_REG_OSR,
+				BMP380_OSRS_TEMP_MASK | BMP380_OSRS_PRESS_MASK,
+				osrs);
+	if (ret < 0) {
+		dev_err(data->dev, "failed to write oversampling register\n");
+		return ret;
+	}
+
+	/* configure output data rate */
+	ret = regmap_write_bits(data->regmap, BMP380_REG_ODR,
+				BMP380_ODRS_MASK, BMP380_ODRS_50HZ);
+	if (ret < 0) {
+		dev_err(data->dev, "failed to write ODR selection register\n");
+		return ret;
+	}
+
+	/* set filter data */
+	ret = regmap_update_bits(data->regmap, BMP380_REG_CONFIG,
+				 BMP380_FILTER_MASK,
+				 FIELD_PREP(BMP380_FILTER_MASK, BMP380_FILTER_3X));
+	if (ret < 0) {
+		dev_err(data->dev, "failed to write config register\n");
+		return ret;
+	}
+
+	/* wait startup_time before verifying config changes */
+	usleep_range(data->start_up_time, data->start_up_time + 100);
+
+	/* check config error flag */
+	ret = regmap_read(data->regmap, BMP380_REG_ERROR, &tmp);
+	if (ret < 0) {
+		dev_err(data->dev,
+			"failed to read error register\n");
+		return ret;
+	}
+	if (tmp & BMP380_ERR_CONF_MASK) {
+		dev_warn(data->dev,
+			 "sensor flagged configuration as incompatible\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static const int bmp380_oversampling_avail[] = { 1, 2, 4, 8, 16, 32 };
+
+static const struct bmp280_chip_info bmp380_chip_info = {
+	.id_reg = BMP380_REG_ID,
+	.start_up_time = 2000,
+	.num_channels = 2,
+
+	.oversampling_temp_avail = bmp380_oversampling_avail,
+	.num_oversampling_temp_avail = ARRAY_SIZE(bmp380_oversampling_avail),
+	.oversampling_temp_default = ilog2(1),
+
+	.oversampling_press_avail = bmp380_oversampling_avail,
+	.num_oversampling_press_avail = ARRAY_SIZE(bmp380_oversampling_avail),
+	.oversampling_press_default = ilog2(4),
+
+	.chip_config = bmp380_chip_config,
+	.read_temp = bmp380_read_temp,
+	.read_press = bmp380_read_press,
+	.read_calib = bmp380_read_calib,
+};
+
 static int bmp180_measure(struct bmp280_data *data, u8 ctrl_meas)
 {
 	int ret;
@@ -1092,6 +1441,9 @@ int bmp280_common_probe(struct device *dev,
 	case BME280_CHIP_ID:
 		chip_info = &bme280_chip_info;
 		break;
+	case BMP380_CHIP_ID:
+		chip_info = &bmp380_chip_info;
+		break;
 	default:
 		return -EINVAL;
 	}
@@ -1149,6 +1501,13 @@ int bmp280_common_probe(struct device *dev,
 		return -EINVAL;
 	}
 
+	/* BMP3xx requires soft-reset as part of initialization */
+	if (chip_id == BMP380_CHIP_ID) {
+		ret = bmp380_cmd(data, BMP380_CMD_SOFT_RESET);
+		if (ret < 0)
+			return ret;
+	}
+
 	ret = data->chip_info->chip_config(data);
 	if (ret < 0)
 		return ret;
diff --git a/drivers/iio/pressure/bmp280-i2c.c b/drivers/iio/pressure/bmp280-i2c.c
index bf4a7a617537..744442dbe5f9 100644
--- a/drivers/iio/pressure/bmp280-i2c.c
+++ b/drivers/iio/pressure/bmp280-i2c.c
@@ -19,6 +19,9 @@ static int bmp280_i2c_probe(struct i2c_client *client,
 	case BME280_CHIP_ID:
 		regmap_config = &bmp280_regmap_config;
 		break;
+	case BMP380_CHIP_ID:
+		regmap_config = &bmp380_regmap_config;
+		break;
 	default:
 		return -EINVAL;
 	}
@@ -37,6 +40,7 @@ static int bmp280_i2c_probe(struct i2c_client *client,
 }
 
 static const struct of_device_id bmp280_of_i2c_match[] = {
+	{ .compatible = "bosch,bmp380", .data = (void *)BMP380_CHIP_ID },
 	{ .compatible = "bosch,bme280", .data = (void *)BME280_CHIP_ID },
 	{ .compatible = "bosch,bmp280", .data = (void *)BMP280_CHIP_ID },
 	{ .compatible = "bosch,bmp180", .data = (void *)BMP180_CHIP_ID },
@@ -46,6 +50,7 @@ static const struct of_device_id bmp280_of_i2c_match[] = {
 MODULE_DEVICE_TABLE(of, bmp280_of_i2c_match);
 
 static const struct i2c_device_id bmp280_i2c_id[] = {
+	{"bmp380", BMP380_CHIP_ID },
 	{"bmp280", BMP280_CHIP_ID },
 	{"bmp180", BMP180_CHIP_ID },
 	{"bmp085", BMP180_CHIP_ID },
diff --git a/drivers/iio/pressure/bmp280-regmap.c b/drivers/iio/pressure/bmp280-regmap.c
index 969698518984..c98c67970265 100644
--- a/drivers/iio/pressure/bmp280-regmap.c
+++ b/drivers/iio/pressure/bmp280-regmap.c
@@ -72,6 +72,49 @@ static bool bmp280_is_volatile_reg(struct device *dev, unsigned int reg)
 	}
 }
 
+static bool bmp380_is_writeable_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case BMP380_REG_CMD:
+	case BMP380_REG_CONFIG:
+	case BMP380_REG_FIFO_CONFIG_1:
+	case BMP380_REG_FIFO_CONFIG_2:
+	case BMP380_REG_FIFO_WATERMARK_LSB:
+	case BMP380_REG_FIFO_WATERMARK_MSB:
+	case BMP380_REG_POWER_CONTROL:
+	case BMP380_REG_INT_CONTROL:
+	case BMP380_REG_IF_CONFIG:
+	case BMP380_REG_ODR:
+	case BMP380_REG_OSR:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static bool bmp380_is_volatile_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case BMP380_REG_TEMP_XLSB:
+	case BMP380_REG_TEMP_LSB:
+	case BMP380_REG_TEMP_MSB:
+	case BMP380_REG_PRESS_XLSB:
+	case BMP380_REG_PRESS_LSB:
+	case BMP380_REG_PRESS_MSB:
+	case BMP380_REG_SENSOR_TIME_XLSB:
+	case BMP380_REG_SENSOR_TIME_LSB:
+	case BMP380_REG_SENSOR_TIME_MSB:
+	case BMP380_REG_INT_STATUS:
+	case BMP380_REG_FIFO_DATA:
+	case BMP380_REG_STATUS:
+	case BMP380_REG_ERROR:
+	case BMP380_REG_EVENT:
+		return true;
+	default:
+		return false;
+	}
+}
+
 const struct regmap_config bmp280_regmap_config = {
 	.reg_bits = 8,
 	.val_bits = 8,
@@ -83,3 +126,15 @@ const struct regmap_config bmp280_regmap_config = {
 	.volatile_reg = bmp280_is_volatile_reg,
 };
 EXPORT_SYMBOL_NS(bmp280_regmap_config, IIO_BMP280);
+
+const struct regmap_config bmp380_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+
+	.max_register = BMP380_REG_CMD,
+	.cache_type = REGCACHE_RBTREE,
+
+	.writeable_reg = bmp380_is_writeable_reg,
+	.volatile_reg = bmp380_is_volatile_reg,
+};
+EXPORT_SYMBOL_NS(bmp380_regmap_config, IIO_BMP280);
diff --git a/drivers/iio/pressure/bmp280-spi.c b/drivers/iio/pressure/bmp280-spi.c
index 4cfaf3e869b8..011c68e07ebf 100644
--- a/drivers/iio/pressure/bmp280-spi.c
+++ b/drivers/iio/pressure/bmp280-spi.c
@@ -66,6 +66,9 @@ static int bmp280_spi_probe(struct spi_device *spi)
 	case BME280_CHIP_ID:
 		regmap_config = &bmp280_regmap_config;
 		break;
+	case BMP380_CHIP_ID:
+		regmap_config = &bmp380_regmap_config;
+		break;
 	default:
 		return -EINVAL;
 	}
@@ -92,6 +95,7 @@ static const struct of_device_id bmp280_of_spi_match[] = {
 	{ .compatible = "bosch,bmp181", },
 	{ .compatible = "bosch,bmp280", },
 	{ .compatible = "bosch,bme280", },
+	{ .compatible = "bosch,bmp380", },
 	{ },
 };
 MODULE_DEVICE_TABLE(of, bmp280_of_spi_match);
@@ -101,6 +105,7 @@ static const struct spi_device_id bmp280_spi_id[] = {
 	{ "bmp181", BMP180_CHIP_ID },
 	{ "bmp280", BMP280_CHIP_ID },
 	{ "bme280", BME280_CHIP_ID },
+	{ "bmp380", BMP380_CHIP_ID },
 	{ }
 };
 MODULE_DEVICE_TABLE(spi, bmp280_spi_id);
diff --git a/drivers/iio/pressure/bmp280.h b/drivers/iio/pressure/bmp280.h
index 57ba0e85db91..fd38906c889c 100644
--- a/drivers/iio/pressure/bmp280.h
+++ b/drivers/iio/pressure/bmp280.h
@@ -3,6 +3,105 @@
 #include <linux/device.h>
 #include <linux/regmap.h>
 
+/* BMP380 specific registers */
+#define BMP380_REG_CMD			0x7E
+#define BMP380_REG_CONFIG		0x1F
+#define BMP380_REG_ODR			0X1D
+#define BMP380_REG_OSR			0X1C
+#define BMP380_REG_POWER_CONTROL	0X1B
+#define BMP380_REG_IF_CONFIG		0X1A
+#define BMP380_REG_INT_CONTROL		0X19
+#define BMP380_REG_INT_STATUS		0X11
+#define BMP380_REG_EVENT		0X10
+#define BMP380_REG_STATUS		0X03
+#define BMP380_REG_ERROR		0X02
+#define BMP380_REG_ID			0X00
+
+#define BMP380_REG_FIFO_CONFIG_1	0X18
+#define BMP380_REG_FIFO_CONFIG_2	0X17
+#define BMP380_REG_FIFO_WATERMARK_MSB	0X16
+#define BMP380_REG_FIFO_WATERMARK_LSB	0X15
+#define BMP380_REG_FIFO_DATA		0X14
+#define BMP380_REG_FIFO_LENGTH_MSB	0X13
+#define BMP380_REG_FIFO_LENGTH_LSB	0X12
+
+#define BMP380_REG_SENSOR_TIME_MSB	0X0E
+#define BMP380_REG_SENSOR_TIME_LSB	0X0D
+#define BMP380_REG_SENSOR_TIME_XLSB	0X0C
+
+#define BMP380_REG_TEMP_MSB		0X09
+#define BMP380_REG_TEMP_LSB		0X08
+#define BMP380_REG_TEMP_XLSB		0X07
+
+#define BMP380_REG_PRESS_MSB		0X06
+#define BMP380_REG_PRESS_LSB		0X05
+#define BMP380_REG_PRESS_XLSB		0X04
+
+#define BMP380_REG_CALIB_TEMP_START	0x31
+#define BMP380_CALIB_REG_COUNT		21
+
+#define BMP380_FILTER_MASK		GENMASK(3, 1)
+#define BMP380_FILTER_OFF		0
+#define BMP380_FILTER_1X		1
+#define BMP380_FILTER_3X		2
+#define BMP380_FILTER_7X		3
+#define BMP380_FILTER_15X		4
+#define BMP380_FILTER_31X		5
+#define BMP380_FILTER_63X		6
+#define BMP380_FILTER_127X		7
+
+#define BMP380_OSRS_TEMP_MASK		GENMASK(5, 3)
+#define BMP380_OSRS_PRESS_MASK		GENMASK(2, 0)
+
+#define BMP380_ODRS_MASK		GENMASK(4, 0)
+#define BMP380_ODRS_200HZ		0x00
+#define BMP380_ODRS_100HZ		0x01
+#define BMP380_ODRS_50HZ		0x02
+#define BMP380_ODRS_25HZ		0x03
+#define BMP380_ODRS_12_5HZ		0x04
+#define BMP380_ODRS_6_25HZ		0x05
+#define BMP380_ODRS_3_1HZ		0x06
+#define BMP380_ODRS_1_5HZ		0x07
+#define BMP380_ODRS_0_78HZ		0x08
+#define BMP380_ODRS_0_39HZ		0x09
+#define BMP380_ODRS_0_2HZ		0x0A
+#define BMP380_ODRS_0_1HZ		0x0B
+#define BMP380_ODRS_0_05HZ		0x0C
+#define BMP380_ODRS_0_02HZ		0x0D
+#define BMP380_ODRS_0_01HZ		0x0E
+#define BMP380_ODRS_0_006HZ		0x0F
+#define BMP380_ODRS_0_003HZ		0x10
+#define BMP380_ODRS_0_0015HZ		0x11
+
+#define BMP380_CTRL_SENSORS_MASK	GENMASK(1, 0)
+#define BMP380_CTRL_SENSORS_PRESS_EN	BIT(0)
+#define BMP380_CTRL_SENSORS_TEMP_EN	BIT(1)
+#define BMP380_MODE_MASK		GENMASK(5, 4)
+#define BMP380_MODE_SLEEP		0
+#define BMP380_MODE_FORCED		1
+#define BMP380_MODE_NORMAL		3
+
+#define BMP380_MIN_TEMP			-4000
+#define BMP380_MAX_TEMP			8500
+#define BMP380_MIN_PRES			3000000
+#define BMP380_MAX_PRES			12500000
+
+#define BMP380_CMD_NOOP			0X00
+#define BMP380_CMD_EXTMODE_EN_MID	0x34
+#define BMP380_CMD_FIFO_FLUSH		0XB0
+#define BMP380_CMD_SOFT_RESET		0xB6
+
+#define BMP380_STATUS_CMD_RDY_MASK	BIT(4)
+#define BMP380_STATUS_DRDY_PRESS_MASK	BIT(5)
+#define BMP380_STATUS_DRDY_TEMP_MASK	BIT(6)
+
+#define BMP380_ERR_FATAL_MASK		BIT(0)
+#define BMP380_ERR_CMD_MASK		BIT(1)
+#define BMP380_ERR_CONF_MASK		BIT(2)
+
+#define BMP380_TEMP_SKIPPED		0x800000
+#define BMP380_PRESS_SKIPPED		0x800000
+
 /* BMP280 specific registers */
 #define BMP280_REG_HUMIDITY_LSB		0xFE
 #define BMP280_REG_HUMIDITY_MSB		0xFD
@@ -92,6 +191,7 @@
 #define BMP280_REG_RESET		0xE0
 #define BMP280_REG_ID			0xD0
 
+#define BMP380_CHIP_ID			0x50
 #define BMP180_CHIP_ID			0x55
 #define BMP280_CHIP_ID			0x58
 #define BME280_CHIP_ID			0x60
@@ -105,6 +205,7 @@
 /* Regmap configurations */
 extern const struct regmap_config bmp180_regmap_config;
 extern const struct regmap_config bmp280_regmap_config;
+extern const struct regmap_config bmp380_regmap_config;
 
 /* Probe called from different transports */
 int bmp280_common_probe(struct device *dev,
-- 
2.37.1

Re: [PATCH v4 4/5] iio: pressure: bmp280: Add support for BMP380 sensor family

[kernel test robot]

Hi Angel,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on 180c6cb6b9b79c55b79e8414f4c0208f2463af7d]

url:    https://github.com/intel-lab-lkp/linux/commits/Angel-Iglesias/Add-support-for-pressure-sensor-Bosch-BMP380/20220724-014146
base:   180c6cb6b9b79c55b79e8414f4c0208f2463af7d
config: arm-buildonly-randconfig-r003-20220724 (https://download.01.org/0day-ci/archive/20220724/202207240654.c7cPESiE-lkp@intel.com/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 12fbd2d377e396ad61bce56d71c98a1eb1bebfa9)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install arm cross compiling tool for clang build
        # apt-get install binutils-arm-linux-gnueabi
        # https://github.com/intel-lab-lkp/linux/commit/eb385b5ff634acc29a3d9f20847e62ec73484fcb
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Angel-Iglesias/Add-support-for-pressure-sensor-Bosch-BMP380/20220724-014146
        git checkout eb385b5ff634acc29a3d9f20847e62ec73484fcb
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

>> ld.lld: error: undefined symbol: __aeabi_ldivmod
   >>> referenced by bmp280-core.c:887 (drivers/iio/pressure/bmp280-core.c:887)
   >>> iio/pressure/bmp280-core.o:(bmp380_read_press) in archive drivers/built-in.a
   >>> did you mean: __aeabi_idivmod
   >>> defined in: arch/arm/lib/lib.a(lib1funcs.o)
   pahole: .tmp_vmlinux.btf: No such file or directory
   ld.lld: error: .btf.vmlinux.bin.o: unknown file type

-- 
0-DAY CI Kernel Test Service
https://01.org/lkp

Re: [PATCH v4 4/5] iio: pressure: bmp280: Add support for BMP380 sensor family

[kernel test robot]

Hi Angel,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on 180c6cb6b9b79c55b79e8414f4c0208f2463af7d]

url:    https://github.com/intel-lab-lkp/linux/commits/Angel-Iglesias/Add-support-for-pressure-sensor-Bosch-BMP380/20220724-014146
base:   180c6cb6b9b79c55b79e8414f4c0208f2463af7d
config: m68k-randconfig-r025-20220724 (https://download.01.org/0day-ci/archive/20220724/202207240750.OtA1GvLw-lkp@intel.com/config)
compiler: m68k-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/intel-lab-lkp/linux/commit/eb385b5ff634acc29a3d9f20847e62ec73484fcb
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Angel-Iglesias/Add-support-for-pressure-sensor-Bosch-BMP380/20220724-014146
        git checkout eb385b5ff634acc29a3d9f20847e62ec73484fcb
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=m68k SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>, old ones prefixed by <<):

>> ERROR: modpost: "__divdi3" [drivers/iio/pressure/bmp280.ko] undefined!

-- 
0-DAY CI Kernel Test Service
https://01.org/lkp

Re: [PATCH v4 4/5] iio: pressure: bmp280: Add support for BMP380 sensor family

[kernel test robot]

Hi Angel,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on 180c6cb6b9b79c55b79e8414f4c0208f2463af7d]

url:    https://github.com/intel-lab-lkp/linux/commits/Angel-Iglesias/Add-support-for-pressure-sensor-Bosch-BMP380/20220724-014146
base:   180c6cb6b9b79c55b79e8414f4c0208f2463af7d
config: i386-randconfig-a002 (https://download.01.org/0day-ci/archive/20220724/202207240827.C5K7s1KU-lkp@intel.com/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 12fbd2d377e396ad61bce56d71c98a1eb1bebfa9)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/intel-lab-lkp/linux/commit/eb385b5ff634acc29a3d9f20847e62ec73484fcb
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Angel-Iglesias/Add-support-for-pressure-sensor-Bosch-BMP380/20220724-014146
        git checkout eb385b5ff634acc29a3d9f20847e62ec73484fcb
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>, old ones prefixed by <<):

>> ERROR: modpost: "__divdi3" [drivers/iio/pressure/bmp280.ko] undefined!

-- 
0-DAY CI Kernel Test Service
https://01.org/lkp

Re: [PATCH v4 4/5] iio: pressure: bmp280: Add support for BMP380 sensor family

[Andy Shevchenko]

On Sat, Jul 23, 2022 at 7:40 PM Angel Iglesias <ang.iglesiasg@gmail.com> 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

...

> +       /* wait for 2ms for command to be proccessed */

processed

> +       dev_dbg(data->dev, "Command 0x%X proccessed successfully\n", cmd);

Ditto. Can you run a spell checker? Kernel has a little one called codespell.

> +
> +       return 0;
> +}

...

> +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;
> +}

...

> +       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;


Kbuild bot is right, you forgot to (compile-)test for a 32-bit machine.

...

> +       ret = regmap_bulk_read(data->regmap, BMP380_REG_TEMP_XLSB, data->buf, 3);

sizeof() ?

...

> +       /* Read and compensate temperature so we get a reading of t_fine. */

for temperature

...

> +       ret = regmap_bulk_read(data->regmap, BMP380_REG_PRESS_XLSB, data->buf, 3);

sizeof() ?

...

> +       .oversampling_temp_default = ilog2(1),

> +       .oversampling_press_default = ilog2(4),

BIT()

...

> +#define BMP380_REG_CMD                 0x7E
> +#define BMP380_REG_CONFIG              0x1F
> +#define BMP380_REG_ODR                 0X1D
> +#define BMP380_REG_OSR                 0X1C
> +#define BMP380_REG_POWER_CONTROL       0X1B
> +#define BMP380_REG_IF_CONFIG           0X1A
> +#define BMP380_REG_INT_CONTROL         0X19
> +#define BMP380_REG_INT_STATUS          0X11
> +#define BMP380_REG_EVENT               0X10
> +#define BMP380_REG_STATUS              0X03
> +#define BMP380_REG_ERROR               0X02
> +#define BMP380_REG_ID                  0X00
> +
> +#define BMP380_REG_FIFO_CONFIG_1       0X18
> +#define BMP380_REG_FIFO_CONFIG_2       0X17
> +#define BMP380_REG_FIFO_WATERMARK_MSB  0X16
> +#define BMP380_REG_FIFO_WATERMARK_LSB  0X15
> +#define BMP380_REG_FIFO_DATA           0X14
> +#define BMP380_REG_FIFO_LENGTH_MSB     0X13
> +#define BMP380_REG_FIFO_LENGTH_LSB     0X12
> +
> +#define BMP380_REG_SENSOR_TIME_MSB     0X0E
> +#define BMP380_REG_SENSOR_TIME_LSB     0X0D
> +#define BMP380_REG_SENSOR_TIME_XLSB    0X0C
> +
> +#define BMP380_REG_TEMP_MSB            0X09
> +#define BMP380_REG_TEMP_LSB            0X08
> +#define BMP380_REG_TEMP_XLSB           0X07
> +
> +#define BMP380_REG_PRESS_MSB           0X06
> +#define BMP380_REG_PRESS_LSB           0X05
> +#define BMP380_REG_PRESS_XLSB          0X04
> +
> +#define BMP380_REG_CALIB_TEMP_START    0x31

Be consistent x vs X (we prefer x).

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v4 4/5] iio: pressure: bmp280: Add support for BMP380 sensor family

[Angel Iglesias]

On lun, 2022-07-25 at 23:15 +0200, Andy Shevchenko wrote:
> On Sat, Jul 23, 2022 at 7:40 PM Angel Iglesias <ang.iglesiasg@gmail.com>
> 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
> 
> ...
> 
> > +       /* wait for 2ms for command to be proccessed */
> 
> processed
> 
> > +       dev_dbg(data->dev, "Command 0x%X proccessed successfully\n", cmd);
> 
> Ditto. Can you run a spell checker? Kernel has a little one called codespell.

Once again, my typos strike back! I didn't know of this tool, I only checked
format issues using the script check_patch.pl

> > +
> > +       return 0;
> > +}
> 
> ...
> 
> > +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;
> > +}
> 
> ...
> 
> > +       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;
> 
> 
> Kbuild bot is right, you forgot to (compile-)test for a 32-bit machine.

Oh I see. Thanks for heads up, I only tested arm64 and x86_64 archs.

> ...
> 
> > +       ret = regmap_bulk_read(data->regmap, BMP380_REG_TEMP_XLSB, data-
> > >buf, 3);
> 
> sizeof() ?
> 
> ...
> 
> > +       /* Read and compensate temperature so we get a reading of t_fine. */
> 
> for temperature
> 
> ...
> 
> > +       ret = regmap_bulk_read(data->regmap, BMP380_REG_PRESS_XLSB, data-
> > >buf, 3);
> 
> sizeof() ?
> 
> ...
> 
> > +       .oversampling_temp_default = ilog2(1),
> 
> > +       .oversampling_press_default = ilog2(4),
> 
> BIT()

I preserved previous committer use of ilog2() to recover the index value as it
is done on bmp280_write_oversampling_* functions, but you're right, is better to
initialize using BIT() macros.

> ...
> ´
> > +#define BMP380_REG_CMD                 0x7E
> > +#define BMP380_REG_CONFIG              0x1F
> > +#define BMP380_REG_ODR                 0X1D
> > +#define BMP380_REG_OSR                 0X1C
> > +#define BMP380_REG_POWER_CONTROL       0X1B
> > +#define BMP380_REG_IF_CONFIG           0X1A
> > +#define BMP380_REG_INT_CONTROL         0X19
> > +#define BMP380_REG_INT_STATUS          0X11
> > +#define BMP380_REG_EVENT               0X10
> > +#define BMP380_REG_STATUS              0X03
> > +#define BMP380_REG_ERROR               0X02
> > +#define BMP380_REG_ID                  0X00
> > +
> > +#define BMP380_REG_FIFO_CONFIG_1       0X18
> > +#define BMP380_REG_FIFO_CONFIG_2       0X17
> > +#define BMP380_REG_FIFO_WATERMARK_MSB  0X16
> > +#define BMP380_REG_FIFO_WATERMARK_LSB  0X15
> > +#define BMP380_REG_FIFO_DATA           0X14
> > +#define BMP380_REG_FIFO_LENGTH_MSB     0X13
> > +#define BMP380_REG_FIFO_LENGTH_LSB     0X12
> > +
> > +#define BMP380_REG_SENSOR_TIME_MSB     0X0E
> > +#define BMP380_REG_SENSOR_TIME_LSB     0X0D
> > +#define BMP380_REG_SENSOR_TIME_XLSB    0X0C
> > +
> > +#define BMP380_REG_TEMP_MSB            0X09
> > +#define BMP380_REG_TEMP_LSB            0X08
> > +#define BMP380_REG_TEMP_XLSB           0X07
> > +
> > +#define BMP380_REG_PRESS_MSB           0X06
> > +#define BMP380_REG_PRESS_LSB           0X05
> > +#define BMP380_REG_PRESS_XLSB          0X04
> > +
> > +#define BMP380_REG_CALIB_TEMP_START    0x31
> 
> Be consistent x vs X (we prefer x).
> 
Sorry about that


As always, thank you for your comments,

Kind regards,
Angel

Re: [PATCH v4 4/5] iio: pressure: bmp280: Add support for BMP380 sensor family

[Jonathan Cameron]

On Sat, 23 Jul 2022 19:39:44 +0200
Angel Iglesias <ang.iglesiasg@gmail.com> 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@gmail.com>

Hi Angel,

A comment below. Follows on from comment on previous patch rather than being a
suggestion to change anything in here (beyond what has already been raised by others!)

Jonathan

> +static int bmp380_read_calib(struct bmp280_data *data, unsigned int chip)
> +{
> +	struct bmp380_calib *calib = &data->calib.bmp380;
> +	int ret;
> +	u8 *buf;
> +
> +	buf = kmalloc(BMP380_CALIB_REG_COUNT, GFP_KERNEL);

Ah. The complexity in here explains somewhat why you did it with u8 in the previous
patch.  Probably still better to have a __be16 buffer for that one though
even though we can't do that here.

> +	if (!buf)
> +		return -ENOMEM;
> +
> +	/* 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");
> +		kfree(buf);
> +		return ret;
> +	}
> +
> +	/* Toss the temperature calibration data into the entropy pool */
> +	add_device_randomness(buf, BMP380_CALIB_REG_COUNT);
> +
> +	/* 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];
> +
> +	kfree(buf);
> +	return 0;
> +}
> +

Re: [PATCH v4 4/5] iio: pressure: bmp280: Add support for BMP380 sensor family

[Angel Iglesias]

On dom, 2022-07-31 at 17:16 +0100, Jonathan Cameron wrote:
> On Sat, 23 Jul 2022 19:39:44 +0200
> Angel Iglesias <ang.iglesiasg@gmail.com> 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@gmail.com>
> 
> Hi Angel,
> 
> A comment below. Follows on from comment on previous patch rather than being a
> suggestion to change anything in here (beyond what has already been raised by
> others!)
> 
> Jonathan
> 
> > +static int bmp380_read_calib(struct bmp280_data *data, unsigned int chip)
> > +{
> > +       struct bmp380_calib *calib = &data->calib.bmp380;
> > +       int ret;
> > +       u8 *buf;
> > +
> > +       buf = kmalloc(BMP380_CALIB_REG_COUNT, GFP_KERNEL);
> 
> Ah. The complexity in here explains somewhat why you did it with u8 in the
> previous
> patch.  Probably still better to have a __be16 buffer for that one though
> even though we can't do that here.

Yes, I thought that, although I had to make more cumbersome the conversions and
do the +2 increment on the enum with the index, it would be better to have a
somewhat more uniform structure in each calib reading function.

> > +       if (!buf)
> > +               return -ENOMEM;
> > +
> > +       /* 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");
> > +               kfree(buf);
> > +               return ret;
> > +       }
> > +
> > +       /* Toss the temperature calibration data into the entropy pool */
> > +       add_device_randomness(buf, BMP380_CALIB_REG_COUNT);
> > +
> > +       /* 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];
> > +
> > +       kfree(buf);
> > +       return 0;
> > +}
> > +

Thanks for your comments,

Kind regards,
Angel

[PATCH v4 5/5] iio: pressure: bmp280: Add more tunable config parameters for BMP380

[Angel Iglesias]

Allows sampling frequency and IIR filter coefficients configuration
using sysfs ABI.

The IIR filter coefficient is configurable using the sysfs attribute
"filter_low_pass_3db_frequency".

Signed-off-by: Angel Iglesias <ang.iglesiasg@gmail.com>
Reported-by: Andy Shevchenko <andy.shevchenko@gmail.com> # uninit var
---
 drivers/iio/pressure/bmp280-core.c | 324 ++++++++++++++++++++++++++---
 drivers/iio/pressure/bmp280.h      |  18 --
 2 files changed, 294 insertions(+), 48 deletions(-)

diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
index f5b1344b8e20..a72e0b011209 100644
--- a/drivers/iio/pressure/bmp280-core.c
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -112,6 +112,27 @@ static const char *const bmp280_supply_names[] = {
 	"vddd", "vdda"
 };
 
+enum bmp380_odr {
+	BMP380_ODR_200HZ,
+	BMP380_ODR_100HZ,
+	BMP380_ODR_50HZ,
+	BMP380_ODR_25HZ,
+	BMP380_ODR_12_5HZ,
+	BMP380_ODR_6_25HZ,
+	BMP380_ODR_3_125HZ,
+	BMP380_ODR_1_5625HZ,
+	BMP380_ODR_0_78HZ,
+	BMP380_ODR_0_39HZ,
+	BMP380_ODR_0_2HZ,
+	BMP380_ODR_0_1HZ,
+	BMP380_ODR_0_05HZ,
+	BMP380_ODR_0_02HZ,
+	BMP380_ODR_0_01HZ,
+	BMP380_ODR_0_006HZ,
+	BMP380_ODR_0_003HZ,
+	BMP380_ODR_0_0015HZ,
+};
+
 #define BMP280_NUM_SUPPLIES ARRAY_SIZE(bmp280_supply_names)
 
 struct bmp280_data {
@@ -133,6 +154,17 @@ struct bmp280_data {
 	u8 oversampling_press;
 	u8 oversampling_temp;
 	u8 oversampling_humid;
+	u8 iir_filter_coeff;
+
+	/*
+	 * BMP380 devices introduce sampling frequency configuration. See
+	 * datasheet sections 3.3.3. and 4.3.19 for more details.
+	 *
+	 * BMx280 devices allowed indirect configuration of sampling frequency
+	 * changing the t_standby duration between measurements, as detailed on
+	 * section 3.6.3 of the datasheet.
+	 */
+	int sampling_freq;
 
 	/*
 	 * Carryover value from temperature conversion, used in pressure
@@ -150,6 +182,7 @@ struct bmp280_data {
 struct bmp280_chip_info {
 	unsigned int id_reg;
 
+	const struct iio_chan_spec *channels;
 	int num_channels;
 	unsigned int start_up_time;
 
@@ -165,6 +198,14 @@ struct bmp280_chip_info {
 	int num_oversampling_humid_avail;
 	int oversampling_humid_default;
 
+	const int *iir_filter_coeffs_avail;
+	int num_iir_filter_coeffs_avail;
+	int iir_filter_coeff_default;
+
+	const int (*sampling_freq_avail)[2];
+	int num_sampling_freq_avail;
+	int sampling_freq_default;
+
 	int (*chip_config)(struct bmp280_data *);
 	int (*read_temp)(struct bmp280_data *, int *);
 	int (*read_press)(struct bmp280_data *, int *, int *);
@@ -226,6 +267,30 @@ static const struct iio_chan_spec bmp280_channels[] = {
 	},
 };
 
+static const struct iio_chan_spec bmp380_channels[] = {
+	{
+		.type = IIO_PRESSURE,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
+				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ) |
+					   BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),
+	},
+	{
+		.type = IIO_TEMP,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
+				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ) |
+					   BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),
+	},
+	{
+		.type = IIO_HUMIDITYRELATIVE,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
+				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ) |
+					   BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),
+	},
+};
+
 static int bmp280_read_calib(struct bmp280_data *data, unsigned int chip)
 {
 	int ret;
@@ -558,6 +623,25 @@ static int bmp280_read_raw(struct iio_dev *indio_dev,
 			break;
 		}
 		break;
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		if (!data->chip_info->sampling_freq_avail) {
+			ret = -EINVAL;
+			break;
+		}
+
+		*val = data->chip_info->sampling_freq_avail[data->sampling_freq][0];
+		*val2 = data->chip_info->sampling_freq_avail[data->sampling_freq][1];
+		ret = IIO_VAL_INT_PLUS_MICRO;
+		break;
+	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+		if (!data->chip_info->iir_filter_coeffs_avail) {
+			ret = -EINVAL;
+			break;
+		}
+
+		*val = data->chip_info->iir_filter_coeffs_avail[data->iir_filter_coeff];
+		ret = IIO_VAL_INT;
+		break;
 	default:
 		ret = -EINVAL;
 		break;
@@ -574,14 +658,22 @@ static int bmp280_write_oversampling_ratio_humid(struct bmp280_data *data,
 					       int val)
 {
 	int i;
+	int ret, prev;
 	const int *avail = data->chip_info->oversampling_humid_avail;
 	const int n = data->chip_info->num_oversampling_humid_avail;
 
 	for (i = 0; i < n; i++) {
 		if (avail[i] == val) {
+			prev = data->oversampling_humid;
 			data->oversampling_humid = ilog2(val);
 
-			return data->chip_info->chip_config(data);
+			ret = data->chip_info->chip_config(data);
+			if (ret) {
+				data->oversampling_humid = prev;
+				data->chip_info->chip_config(data);
+				return ret;
+			}
+			return 0;
 		}
 	}
 	return -EINVAL;
@@ -591,14 +683,22 @@ static int bmp280_write_oversampling_ratio_temp(struct bmp280_data *data,
 					       int val)
 {
 	int i;
+	int ret, prev;
 	const int *avail = data->chip_info->oversampling_temp_avail;
 	const int n = data->chip_info->num_oversampling_temp_avail;
 
 	for (i = 0; i < n; i++) {
 		if (avail[i] == val) {
+			prev = data->oversampling_temp;
 			data->oversampling_temp = ilog2(val);
 
-			return data->chip_info->chip_config(data);
+			ret = data->chip_info->chip_config(data);
+			if (ret) {
+				data->oversampling_temp = prev;
+				data->chip_info->chip_config(data);
+				return ret;
+			}
+			return 0;
 		}
 	}
 	return -EINVAL;
@@ -608,14 +708,72 @@ static int bmp280_write_oversampling_ratio_press(struct bmp280_data *data,
 					       int val)
 {
 	int i;
+	int ret, prev;
 	const int *avail = data->chip_info->oversampling_press_avail;
 	const int n = data->chip_info->num_oversampling_press_avail;
 
 	for (i = 0; i < n; i++) {
 		if (avail[i] == val) {
+			prev = data->oversampling_press;
 			data->oversampling_press = ilog2(val);
 
-			return data->chip_info->chip_config(data);
+			ret = data->chip_info->chip_config(data);
+			if (ret) {
+				data->oversampling_press = prev;
+				data->chip_info->chip_config(data);
+				return ret;
+			}
+			return 0;
+		}
+	}
+	return -EINVAL;
+}
+
+static int bmp280_write_sampling_frequency(struct bmp280_data *data,
+					   int val, int val2)
+{
+	int i;
+	int ret, prev;
+	const int (*avail)[2] = data->chip_info->sampling_freq_avail;
+	const int n = data->chip_info->num_sampling_freq_avail;
+
+	for (i = 0; i < n; i++) {
+		if (avail[i][0] == val && avail[i][1] == val2) {
+			prev = data->sampling_freq;
+			data->sampling_freq = i;
+
+			ret = data->chip_info->chip_config(data);
+			if (ret) {
+				data->sampling_freq = prev;
+				data->chip_info->chip_config(data);
+				return ret;
+			}
+			return 0;
+		}
+	}
+	return -EINVAL;
+}
+
+static int bmp280_write_iir_filter_coeffs(struct bmp280_data *data, int val)
+{
+	int i;
+	int ret, prev;
+	const int *avail = data->chip_info->iir_filter_coeffs_avail;
+	const int n = data->chip_info->num_iir_filter_coeffs_avail;
+
+	for (i = 0; i < n; i++) {
+		if (avail[i] == val) {
+			prev = data->iir_filter_coeff;
+			data->iir_filter_coeff = i;
+
+			ret = data->chip_info->chip_config(data);
+			if (ret) {
+				data->iir_filter_coeff = prev;
+				data->chip_info->chip_config(data);
+				return ret;
+
+			}
+			return 0;
 		}
 	}
 	return -EINVAL;
@@ -628,6 +786,12 @@ static int bmp280_write_raw(struct iio_dev *indio_dev,
 	int ret = 0;
 	struct bmp280_data *data = iio_priv(indio_dev);
 
+	/*
+	 * Auxiliar functions to update sensor running configuration.
+	 * If an error happens applying new settings, will try restore
+	 * previous parameters to ensure the sensor is left in a known
+	 * working configuration.
+	 */
 	switch (mask) {
 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
 		pm_runtime_get_sync(data->dev);
@@ -650,6 +814,22 @@ static int bmp280_write_raw(struct iio_dev *indio_dev,
 		pm_runtime_mark_last_busy(data->dev);
 		pm_runtime_put_autosuspend(data->dev);
 		break;
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		pm_runtime_get_sync(data->dev);
+		mutex_lock(&data->lock);
+		ret = bmp280_write_sampling_frequency(data, val, val2);
+		mutex_unlock(&data->lock);
+		pm_runtime_mark_last_busy(data->dev);
+		pm_runtime_put_autosuspend(data->dev);
+		break;
+	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+		pm_runtime_get_sync(data->dev);
+		mutex_lock(&data->lock);
+		ret = bmp280_write_iir_filter_coeffs(data, val);
+		mutex_unlock(&data->lock);
+		pm_runtime_mark_last_busy(data->dev);
+		pm_runtime_put_autosuspend(data->dev);
+		break;
 	default:
 		return -EINVAL;
 	}
@@ -680,6 +860,17 @@ static int bmp280_read_avail(struct iio_dev *indio_dev,
 		}
 		*type = IIO_VAL_INT;
 		return IIO_AVAIL_LIST;
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		*vals = (const int *)data->chip_info->sampling_freq_avail;
+		*type = IIO_VAL_INT_PLUS_MICRO;
+		/* Values are stored in a 2D matrix */
+		*length = data->chip_info->num_sampling_freq_avail;
+		return IIO_AVAIL_LIST;
+	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+		*vals = data->chip_info->iir_filter_coeffs_avail;
+		*type = IIO_VAL_INT;
+		*length = data->chip_info->num_iir_filter_coeffs_avail;
+		return IIO_AVAIL_LIST;
 	default:
 		return -EINVAL;
 	}
@@ -725,6 +916,7 @@ static const int bmp280_oversampling_avail[] = { 1, 2, 4, 8, 16 };
 static const struct bmp280_chip_info bmp280_chip_info = {
 	.id_reg = BMP280_REG_ID,
 	.start_up_time = 2000,
+	.channels = bmp280_channels,
 	.num_channels = 2,
 
 	.oversampling_temp_avail = bmp280_oversampling_avail,
@@ -762,6 +954,7 @@ static int bme280_chip_config(struct bmp280_data *data)
 static const struct bmp280_chip_info bme280_chip_info = {
 	.id_reg = BMP280_REG_ID,
 	.start_up_time = 2000,
+	.channels = bmp280_channels,
 	.num_channels = 3,
 
 	.oversampling_temp_avail = bmp280_oversampling_avail,
@@ -1004,18 +1197,39 @@ static int bmp380_read_calib(struct bmp280_data *data, unsigned int chip)
 	return 0;
 }
 
+static const int bmp380_odr_table[][2] = {
+	[BMP380_ODR_200HZ]	= {200, 0},
+	[BMP380_ODR_100HZ]	= {100, 0},
+	[BMP380_ODR_50HZ]	= {50, 0},
+	[BMP380_ODR_25HZ]	= {25, 0},
+	[BMP380_ODR_12_5HZ]	= {12, 500000},
+	[BMP380_ODR_6_25HZ]	= {6, 250000},
+	[BMP380_ODR_3_125HZ]	= {3, 125000},
+	[BMP380_ODR_1_5625HZ]	= {1, 562500},
+	[BMP380_ODR_0_78HZ]	= {0, 781250},
+	[BMP380_ODR_0_39HZ]	= {0, 390625},
+	[BMP380_ODR_0_2HZ]	= {0, 195313},
+	[BMP380_ODR_0_1HZ]	= {0, 97656},
+	[BMP380_ODR_0_05HZ]	= {0, 48828},
+	[BMP380_ODR_0_02HZ]	= {0, 24414},
+	[BMP380_ODR_0_01HZ]	= {0, 12207},
+	[BMP380_ODR_0_006HZ]	= {0, 6104},
+	[BMP380_ODR_0_003HZ]	= {0, 3052},
+	[BMP380_ODR_0_0015HZ]	= {0, 1526},
+};
+
 static int bmp380_chip_config(struct bmp280_data *data)
 {
+	bool change = false, aux;
 	unsigned int tmp;
 	u8 osrs;
 	int ret;
 
 	/* configure power control register */
-	ret = regmap_write_bits(data->regmap, BMP380_REG_POWER_CONTROL,
-				BMP380_CTRL_SENSORS_MASK | BMP380_MODE_MASK,
-				BMP380_CTRL_SENSORS_PRESS_EN |
-				BMP380_CTRL_SENSORS_TEMP_EN |
-				FIELD_PREP(BMP380_MODE_MASK, BMP380_MODE_NORMAL));
+	ret = regmap_update_bits(data->regmap, BMP380_REG_POWER_CONTROL,
+				 BMP380_CTRL_SENSORS_MASK,
+				 BMP380_CTRL_SENSORS_PRESS_EN |
+				 BMP380_CTRL_SENSORS_TEMP_EN);
 	if (ret < 0) {
 		dev_err(data->dev,
 			"failed to write operation control register\n");
@@ -1026,55 +1240,94 @@ static int bmp380_chip_config(struct bmp280_data *data)
 	osrs = FIELD_PREP(BMP380_OSRS_TEMP_MASK, data->oversampling_temp) |
 	       FIELD_PREP(BMP380_OSRS_PRESS_MASK, data->oversampling_press);
 
-	ret = regmap_write_bits(data->regmap, BMP380_REG_OSR,
-				BMP380_OSRS_TEMP_MASK | BMP380_OSRS_PRESS_MASK,
-				osrs);
+	ret = regmap_update_bits_check(data->regmap, BMP380_REG_OSR,
+				       BMP380_OSRS_TEMP_MASK |
+				       BMP380_OSRS_PRESS_MASK,
+				       osrs, &aux);
 	if (ret < 0) {
 		dev_err(data->dev, "failed to write oversampling register\n");
 		return ret;
 	}
+	change = change || aux;
 
 	/* configure output data rate */
-	ret = regmap_write_bits(data->regmap, BMP380_REG_ODR,
-				BMP380_ODRS_MASK, BMP380_ODRS_50HZ);
+	ret = regmap_update_bits_check(data->regmap, BMP380_REG_ODR,
+				       BMP380_ODRS_MASK, data->sampling_freq,
+				       &aux);
 	if (ret < 0) {
 		dev_err(data->dev, "failed to write ODR selection register\n");
 		return ret;
 	}
+	change = change || aux;
 
 	/* set filter data */
-	ret = regmap_update_bits(data->regmap, BMP380_REG_CONFIG,
-				 BMP380_FILTER_MASK,
-				 FIELD_PREP(BMP380_FILTER_MASK, BMP380_FILTER_3X));
+	ret = regmap_update_bits_check(data->regmap, BMP380_REG_CONFIG,
+				BMP380_FILTER_MASK,
+				FIELD_PREP(BMP380_FILTER_MASK, data->iir_filter_coeff),
+				&aux);
 	if (ret < 0) {
 		dev_err(data->dev, "failed to write config register\n");
 		return ret;
 	}
+	change = change || aux;
 
-	/* wait startup_time before verifying config changes */
-	usleep_range(data->start_up_time, data->start_up_time + 100);
+	if (change) {
+		/*
+		 * Configuration errors are detected on the fly during a measurement
+		 * cycle. If the sampling frequency is too low, it's faster to reset
+		 * measurement loop than wait until next measurement is due.
+		 *
+		 * Resets sensor measurement loop toggling between sleep and normal
+		 * operating modes.
+		 */
+		ret = regmap_write_bits(data->regmap, BMP380_REG_POWER_CONTROL,
+					BMP380_MODE_MASK,
+					FIELD_PREP(BMP380_MODE_MASK,
+						   BMP380_MODE_SLEEP));
+		if (ret < 0) {
+			dev_err(data->dev, "failed to set sleep mode\n");
+			return ret;
+		}
+		usleep_range(2000, 2500);
+		ret = regmap_write_bits(data->regmap, BMP380_REG_POWER_CONTROL,
+					BMP380_MODE_MASK,
+					FIELD_PREP(BMP380_MODE_MASK,
+						   BMP380_MODE_NORMAL));
+		if (ret < 0) {
+			dev_err(data->dev, "failed to set normal mode\n");
+			return ret;
+		}
+		/*
+		 * Waits for measurement before checking configuration error flag.
+		 * Selected longest measure time indicated in section 3.9.1
+		 * in the datasheet.
+		 */
+		msleep(80);
 
-	/* check config error flag */
-	ret = regmap_read(data->regmap, BMP380_REG_ERROR, &tmp);
-	if (ret < 0) {
-		dev_err(data->dev,
-			"failed to read error register\n");
-		return ret;
-	}
-	if (tmp & BMP380_ERR_CONF_MASK) {
-		dev_warn(data->dev,
-			 "sensor flagged configuration as incompatible\n");
-		return -EINVAL;
+		/* check config error flag */
+		ret = regmap_read(data->regmap, BMP380_REG_ERROR, &tmp);
+		if (ret < 0) {
+			dev_err(data->dev,
+				"failed to read error register\n");
+			return ret;
+		}
+		if (tmp & BMP380_ERR_CONF_MASK) {
+			dev_warn(data->dev,
+				"sensor flagged configuration as incompatible\n");
+			return -EINVAL;
+		}
 	}
 
 	return 0;
 }
 
 static const int bmp380_oversampling_avail[] = { 1, 2, 4, 8, 16, 32 };
+static const int bmp380_iir_filter_coeffs_avail[] = { 0, 1, 3, 7, 15, 31, 63, 127 };
 
 static const struct bmp280_chip_info bmp380_chip_info = {
 	.id_reg = BMP380_REG_ID,
 	.start_up_time = 2000,
+	.channels = bmp380_channels,
 	.num_channels = 2,
 
 	.oversampling_temp_avail = bmp380_oversampling_avail,
@@ -1085,6 +1338,14 @@ static const struct bmp280_chip_info bmp380_chip_info = {
 	.num_oversampling_press_avail = ARRAY_SIZE(bmp380_oversampling_avail),
 	.oversampling_press_default = ilog2(4),
 
+	.sampling_freq_avail = bmp380_odr_table,
+	.num_sampling_freq_avail = ARRAY_SIZE(bmp380_odr_table) * 2,
+	.sampling_freq_default = BMP380_ODR_50HZ,
+
+	.iir_filter_coeffs_avail = bmp380_iir_filter_coeffs_avail,
+	.num_iir_filter_coeffs_avail = ARRAY_SIZE(bmp380_iir_filter_coeffs_avail),
+	.iir_filter_coeff_default = 2,
+
 	.chip_config = bmp380_chip_config,
 	.read_temp = bmp380_read_temp,
 	.read_press = bmp380_read_press,
@@ -1329,6 +1590,7 @@ static const int bmp180_oversampling_press_avail[] = { 1, 2, 4, 8 };
 static const struct bmp280_chip_info bmp180_chip_info = {
 	.id_reg = BMP280_REG_ID,
 	.start_up_time = 2000,
+	.channels = bmp280_channels,
 	.num_channels = 2,
 
 	.oversampling_temp_avail = bmp180_oversampling_temp_avail,
@@ -1427,7 +1689,6 @@ int bmp280_common_probe(struct device *dev,
 	data->dev = dev;
 
 	indio_dev->name = name;
-	indio_dev->channels = bmp280_channels;
 	indio_dev->info = &bmp280_info;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 
@@ -1450,10 +1711,13 @@ int bmp280_common_probe(struct device *dev,
 	data->chip_info = chip_info;
 
 	/* apply initial values from chip info structure */
+	indio_dev->channels = chip_info->channels;
 	indio_dev->num_channels = chip_info->num_channels;
 	data->oversampling_press = chip_info->oversampling_press_default;
 	data->oversampling_humid = chip_info->oversampling_humid_default;
 	data->oversampling_temp = chip_info->oversampling_temp_default;
+	data->iir_filter_coeff = chip_info->iir_filter_coeff_default;
+	data->sampling_freq = chip_info->sampling_freq_default;
 	data->start_up_time = chip_info->start_up_time;
 
 	/* Bring up regulators */
diff --git a/drivers/iio/pressure/bmp280.h b/drivers/iio/pressure/bmp280.h
index fd38906c889c..1314d5059c53 100644
--- a/drivers/iio/pressure/bmp280.h
+++ b/drivers/iio/pressure/bmp280.h
@@ -54,24 +54,6 @@
 #define BMP380_OSRS_PRESS_MASK		GENMASK(2, 0)
 
 #define BMP380_ODRS_MASK		GENMASK(4, 0)
-#define BMP380_ODRS_200HZ		0x00
-#define BMP380_ODRS_100HZ		0x01
-#define BMP380_ODRS_50HZ		0x02
-#define BMP380_ODRS_25HZ		0x03
-#define BMP380_ODRS_12_5HZ		0x04
-#define BMP380_ODRS_6_25HZ		0x05
-#define BMP380_ODRS_3_1HZ		0x06
-#define BMP380_ODRS_1_5HZ		0x07
-#define BMP380_ODRS_0_78HZ		0x08
-#define BMP380_ODRS_0_39HZ		0x09
-#define BMP380_ODRS_0_2HZ		0x0A
-#define BMP380_ODRS_0_1HZ		0x0B
-#define BMP380_ODRS_0_05HZ		0x0C
-#define BMP380_ODRS_0_02HZ		0x0D
-#define BMP380_ODRS_0_01HZ		0x0E
-#define BMP380_ODRS_0_006HZ		0x0F
-#define BMP380_ODRS_0_003HZ		0x10
-#define BMP380_ODRS_0_0015HZ		0x11
 
 #define BMP380_CTRL_SENSORS_MASK	GENMASK(1, 0)
 #define BMP380_CTRL_SENSORS_PRESS_EN	BIT(0)
-- 
2.37.1

Re: [PATCH v4 5/5] iio: pressure: bmp280: Add more tunable config parameters for BMP380

[Andy Shevchenko]

On Sat, Jul 23, 2022 at 7:40 PM Angel Iglesias <ang.iglesiasg@gmail.com> wrote:
>
> Allows sampling frequency and IIR filter coefficients configuration
> using sysfs ABI.
>
> The IIR filter coefficient is configurable using the sysfs attribute
> "filter_low_pass_3db_frequency".
>
> Signed-off-by: Angel Iglesias <ang.iglesiasg@gmail.com>

> Reported-by: Andy Shevchenko <andy.shevchenko@gmail.com> # uninit var

Bugs in new features can't have Reported-by tag.

If you wish to give credit, use a cover letter / changelog.

...

> +               /*
> +                * Configuration errors are detected on the fly during a measurement

The configurations

> +                * cycle. If the sampling frequency is too low, it's faster to reset
> +                * measurement loop than wait until next measurement is due.

the measurement
the next

> +                * Resets sensor measurement loop toggling between sleep and normal
> +                * operating modes.
> +                */

-- 
With Best Regards,
Andy Shevchenko