[PATCH v6 0/9] iio: pressure: bmp280: Add triggered buffer support and

[PATCH v6 0/9] iio: pressure: bmp280: Add triggered buffer support and

[Vasileios Amoiridis]

Based on upstream master with the previous patches of this series applied
as well.

IMPORTANT NOTE: There is a fix queued up for this driver here [1]. It is going
to conflict with PATCH [7-9/9]. The previous patches should be fine. The
solution should be quite trivial with minor changes in all 3 PATCH [7-9/9].
When it is deemed necessary I can resubmit the patches or help with resolving
the issue.

Changes in v6:

PATCH [1-3/9]: new:
	- split of PATCH [5/10] of v5 according to proposal here [2].

PATCH [4/9]: new:
	- split of PATCH [6/10] of v5 according to proposal here [3].

PATCH [6/9]:
	- Removed mutex_lock() and added guard(mutex) to
	  bmp580_nvmem_{read/write}() functions as well.

PATCH [9/9]:
	- In the buffer handlers, add 'goto out;' instead of just returning the
	  error because iio_trigger_notify_done() wouldn't be called in case of
	  error.

[1]: https://lore.kernel.org/linux-iio/043f2be49df3c11152aaf32fc5467ed43fd59faa.camel@gmail.com/
[2]: https://lore.kernel.org/linux-iio/20240505200818.1e70c664@jic23-huawei/
[3]: https://lore.kernel.org/linux-iio/20240505202106.1c780044@jic23-huawei/

Previous versions:

[v5]: https://lore.kernel.org/linux-iio/20240429190046.24252-1-vassilisamir@gmail.com/
[v4]: https://lore.kernel.org/linux-iio/20240407172920.264282-1-vassilisamir@gmail.com/
[v3]: https://lore.kernel.org/linux-iio/20240319002925.2121016-1-vassilisamir@gmail.com/
[v2]: https://lore.kernel.org/linux-iio/20240313174007.1934983-1-vassilisamir@gmail.com/
[v1]: https://lore.kernel.org/linux-iio/20240303165300.468011-1-vassilisamir@gmail.com/

P.S: I messed up before and I sent the patches without versioning. The wrong
thread is here: https://lore.kernel.org/linux-iio/20240508163425.143831-1-vassilisamir@gmail.com

Vasileios Amoiridis (9):
  iio: pressure: bmp280: Remove dead error checks
  iio: pressure: bmp280: Remove, add and update error messages
  iio: pressure: bmp280: Make error checks consistent
  iio: pressure: bmp280: Use unsigned data types for raw sensor data
  iio: pressure: bmp280: Refactorize reading functions
  iio: pressure: bmp280: Introduce new cleanup routines
  iio: pressure: bmp280: Generalize read_{temp,press,humid}() functions
  iio: pressure: bmp280: Add SCALE, RAW values in channels and
    refactorize them
  iio: pressure: bmp280: Add triggered buffer support

 drivers/iio/pressure/Kconfig       |    2 +
 drivers/iio/pressure/bmp280-core.c | 1130 ++++++++++++++++++++--------
 drivers/iio/pressure/bmp280-spi.c  |    8 +-
 drivers/iio/pressure/bmp280.h      |   34 +-
 4 files changed, 844 insertions(+), 330 deletions(-)


base-commit: dccb07f2914cdab2ac3a5b6c98406f765acab803
-- 
2.25.1

[PATCH v6 1/9] iio: pressure: bmp280: Remove dead error checks

[Vasileios Amoiridis]

The ret value is being checked already in all the previous
paths which exit in case of error, so this path can never
become true.

Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
---
 drivers/iio/pressure/bmp280-core.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
index ed49e0779d41..311a011604da 100644
--- a/drivers/iio/pressure/bmp280-core.c
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -1350,10 +1350,6 @@ static int bmp580_nvm_operation(struct bmp280_data *data, bool is_write)
 		poll = 50;
 		timeout = 400;
 	}
-	if (ret) {
-		dev_err(data->dev, "failed to write command sequence\n");
-		return -EIO;
-	}
 
 	/* Wait until NVM is ready again */
 	ret = regmap_read_poll_timeout(data->regmap, BMP580_REG_STATUS, reg,

base-commit: dccb07f2914cdab2ac3a5b6c98406f765acab803
prerequisite-patch-id: 97b99b1106cbfd65cef8d256e4dc1a3a9257511e
prerequisite-patch-id: c60e8ef6fae62417c3430b7598b1a3d2a551be79
prerequisite-patch-id: 6a49484a6d154ddcd1b45b71a6be2c3542ae0be6
prerequisite-patch-id: 5aae62fa92c719fb65a8701ec4e1c4284bef7fd9
prerequisite-patch-id: 6943297d5f70f74bfcf5d5b26198423e428773d9
-- 
2.25.1

Re: [PATCH v6 1/9] iio: pressure: bmp280: Remove dead error checks

[Jonathan Cameron]

On Wed,  8 May 2024 18:51:59 +0200
Vasileios Amoiridis <vassilisamir@gmail.com> wrote:

> The ret value is being checked already in all the previous
> paths which exit in case of error, so this path can never
> become true.
> 
> Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
Applied to the togreg branch of iio.git, but only initially pushed out
as testing because I'll be rebasing that branch on 6.10-rc1 in about 2 weeks
time.

Jonathan

> ---
>  drivers/iio/pressure/bmp280-core.c | 4 ----
>  1 file changed, 4 deletions(-)
> 
> diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
> index ed49e0779d41..311a011604da 100644
> --- a/drivers/iio/pressure/bmp280-core.c
> +++ b/drivers/iio/pressure/bmp280-core.c
> @@ -1350,10 +1350,6 @@ static int bmp580_nvm_operation(struct bmp280_data *data, bool is_write)
>  		poll = 50;
>  		timeout = 400;
>  	}
> -	if (ret) {
> -		dev_err(data->dev, "failed to write command sequence\n");
> -		return -EIO;
> -	}
>  
>  	/* Wait until NVM is ready again */
>  	ret = regmap_read_poll_timeout(data->regmap, BMP580_REG_STATUS, reg,
> 
> base-commit: dccb07f2914cdab2ac3a5b6c98406f765acab803
> prerequisite-patch-id: 97b99b1106cbfd65cef8d256e4dc1a3a9257511e
> prerequisite-patch-id: c60e8ef6fae62417c3430b7598b1a3d2a551be79
> prerequisite-patch-id: 6a49484a6d154ddcd1b45b71a6be2c3542ae0be6
> prerequisite-patch-id: 5aae62fa92c719fb65a8701ec4e1c4284bef7fd9
> prerequisite-patch-id: 6943297d5f70f74bfcf5d5b26198423e428773d9

[PATCH v6 2/9] iio: pressure: bmp280: Remove, add and update error messages

[Vasileios Amoiridis]

Remove duplicate error messages, add missing error messages and
update redundant ones.

Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
---
 drivers/iio/pressure/bmp280-core.c | 55 +++++++++++++++++++++---------
 1 file changed, 38 insertions(+), 17 deletions(-)

diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
index 311a011604da..0aa16fb135c1 100644
--- a/drivers/iio/pressure/bmp280-core.c
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -222,10 +222,8 @@ static int bme280_read_calib(struct bmp280_data *data)
 
 	/* Load shared calibration params with bmp280 first */
 	ret = bmp280_read_calib(data);
-	if  (ret < 0) {
-		dev_err(dev, "failed to read calibration parameters\n");
+	if  (ret < 0)
 		return ret;
-	}
 
 	/*
 	 * Read humidity calibration values.
@@ -841,8 +839,10 @@ static int bme280_chip_config(struct bmp280_data *data)
 	 */
 	ret = regmap_update_bits(data->regmap, BME280_REG_CTRL_HUMIDITY,
 				 BME280_OSRS_HUMIDITY_MASK, osrs);
-	if (ret < 0)
+	if (ret < 0) {
+		dev_err(data->dev, "failed to set humidity oversampling");
 		return ret;
+	}
 
 	return bmp280_chip_config(data);
 }
@@ -1071,7 +1071,7 @@ static int bmp380_read_calib(struct bmp280_data *data)
 			       sizeof(data->bmp380_cal_buf));
 	if (ret) {
 		dev_err(data->dev,
-			"failed to read temperature calibration parameters\n");
+			"failed to read calibration parameters\n");
 		return ret;
 	}
 
@@ -1609,20 +1609,24 @@ static int bmp580_preinit(struct bmp280_data *data)
 
 	/* Post powerup sequence */
 	ret = regmap_read(data->regmap, BMP580_REG_CHIP_ID, &reg);
-	if (ret)
+	if (ret) {
+		dev_err(data->dev, "failed to establish comms with the chip\n");
 		return ret;
+	}
 
 	/* Print warn message if we don't know the chip id */
 	if (reg != BMP580_CHIP_ID && reg != BMP580_CHIP_ID_ALT)
-		dev_warn(data->dev, "preinit: unexpected chip_id\n");
+		dev_warn(data->dev, "unexpected chip_id\n");
 
 	ret = regmap_read(data->regmap, BMP580_REG_STATUS, &reg);
-	if (ret)
+	if (ret) {
+		dev_err(data->dev, "failed to read nvm status\n");
 		return ret;
+	}
 
 	/* Check nvm status */
 	if (!(reg & BMP580_STATUS_NVM_RDY_MASK) || (reg & BMP580_STATUS_NVM_ERR_MASK)) {
-		dev_err(data->dev, "preinit: nvm error on powerup sequence\n");
+		dev_err(data->dev, "nvm error on powerup sequence\n");
 		return -EIO;
 	}
 
@@ -1657,6 +1661,10 @@ static int bmp580_chip_config(struct bmp280_data *data)
 				 BMP580_DSP_COMP_MASK |
 				 BMP580_DSP_SHDW_IIR_TEMP_EN |
 				 BMP580_DSP_SHDW_IIR_PRESS_EN, reg_val);
+	if (ret) {
+		dev_err(data->dev, "failed to change DSP mode settings\n");
+		return ret;
+	}
 
 	/* Configure oversampling */
 	reg_val = FIELD_PREP(BMP580_OSR_TEMP_MASK, data->oversampling_temp) |
@@ -1778,8 +1786,10 @@ static int bmp180_wait_for_eoc(struct bmp280_data *data, u8 ctrl_meas)
 		reinit_completion(&data->done);
 
 	ret = regmap_write(data->regmap, BMP280_REG_CTRL_MEAS, ctrl_meas);
-	if (ret)
+	if (ret) {
+		dev_err(data->dev, "failed to write crtl_meas register\n");
 		return ret;
+	}
 
 	if (data->use_eoc) {
 		/*
@@ -1802,12 +1812,16 @@ static int bmp180_wait_for_eoc(struct bmp280_data *data, u8 ctrl_meas)
 	}
 
 	ret = regmap_read(data->regmap, BMP280_REG_CTRL_MEAS, &ctrl);
-	if (ret)
+	if (ret) {
+		dev_err(data->dev, "failed to read ctrl_meas register\n");
 		return ret;
+	}
 
 	/* The value of this bit reset to "0" after conversion is complete */
-	if (ctrl & BMP180_MEAS_SCO)
+	if (ctrl & BMP180_MEAS_SCO) {
+		dev_err(data->dev, "conversion didn't complete\n");
 		return -EIO;
+	}
 
 	return 0;
 }
@@ -1824,8 +1838,10 @@ static int bmp180_read_adc_temp(struct bmp280_data *data, int *val)
 
 	ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB,
 			       &data->be16, sizeof(data->be16));
-	if (ret)
+	if (ret) {
+		dev_err(data->dev, "failed to read temperature\n");
 		return ret;
+	}
 
 	*val = be16_to_cpu(data->be16);
 
@@ -1840,9 +1856,10 @@ static int bmp180_read_calib(struct bmp280_data *data)
 
 	ret = regmap_bulk_read(data->regmap, BMP180_REG_CALIB_START,
 			       data->bmp180_cal_buf, sizeof(data->bmp180_cal_buf));
-
-	if (ret < 0)
+	if (ret < 0) {
+		dev_err(data->dev, "failed to read calibration parameters\n");
 		return ret;
+	}
 
 	/* None of the words has the value 0 or 0xFFFF */
 	for (i = 0; i < ARRAY_SIZE(data->bmp180_cal_buf); i++) {
@@ -1925,8 +1942,10 @@ static int bmp180_read_adc_press(struct bmp280_data *data, int *val)
 
 	ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB,
 			       data->buf, sizeof(data->buf));
-	if (ret)
+	if (ret) {
+		dev_err(data->dev, "failed to read pressure\n");
 		return ret;
+	}
 
 	*val = get_unaligned_be24(data->buf) >> (8 - oss);
 
@@ -2158,8 +2177,10 @@ int bmp280_common_probe(struct device *dev,
 	data->regmap = regmap;
 
 	ret = regmap_read(regmap, data->chip_info->id_reg, &chip_id);
-	if (ret < 0)
+	if (ret < 0) {
+		dev_err(data->dev, "failed to read chip id\n");
 		return ret;
+	}
 
 	for (i = 0; i < data->chip_info->num_chip_id; i++) {
 		if (chip_id == data->chip_info->chip_id[i]) {
-- 
2.25.1

Re: [PATCH v6 2/9] iio: pressure: bmp280: Remove, add and update error messages

[Jonathan Cameron]

On Wed,  8 May 2024 18:52:00 +0200
Vasileios Amoiridis <vassilisamir@gmail.com> wrote:

> Remove duplicate error messages, add missing error messages and
> update redundant ones.
> 
> Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
Hi Vasileios,

Ideally the one case where you are adding a missing error check should
have been a separate patch, but instead of splitting it I've just
added a note on that to the commit message.

Applied 

Jonathan

> ---
>  drivers/iio/pressure/bmp280-core.c | 55 +++++++++++++++++++++---------
>  1 file changed, 38 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
> index 311a011604da..0aa16fb135c1 100644
> --- a/drivers/iio/pressure/bmp280-core.c
> +++ b/drivers/iio/pressure/bmp280-core.c
> @@ -222,10 +222,8 @@ static int bme280_read_calib(struct bmp280_data *data)
>  
>  	/* Load shared calibration params with bmp280 first */
>  	ret = bmp280_read_calib(data);
> -	if  (ret < 0) {
> -		dev_err(dev, "failed to read calibration parameters\n");
> +	if  (ret < 0)
>  		return ret;
> -	}
>  
>  	/*
>  	 * Read humidity calibration values.
> @@ -841,8 +839,10 @@ static int bme280_chip_config(struct bmp280_data *data)
>  	 */
>  	ret = regmap_update_bits(data->regmap, BME280_REG_CTRL_HUMIDITY,
>  				 BME280_OSRS_HUMIDITY_MASK, osrs);
> -	if (ret < 0)
> +	if (ret < 0) {
> +		dev_err(data->dev, "failed to set humidity oversampling");
>  		return ret;
> +	}
>  
>  	return bmp280_chip_config(data);
>  }
> @@ -1071,7 +1071,7 @@ static int bmp380_read_calib(struct bmp280_data *data)
>  			       sizeof(data->bmp380_cal_buf));
>  	if (ret) {
>  		dev_err(data->dev,
> -			"failed to read temperature calibration parameters\n");
> +			"failed to read calibration parameters\n");
>  		return ret;
>  	}
>  
> @@ -1609,20 +1609,24 @@ static int bmp580_preinit(struct bmp280_data *data)
>  
>  	/* Post powerup sequence */
>  	ret = regmap_read(data->regmap, BMP580_REG_CHIP_ID, &reg);
> -	if (ret)
> +	if (ret) {
> +		dev_err(data->dev, "failed to establish comms with the chip\n");
>  		return ret;
> +	}
>  
>  	/* Print warn message if we don't know the chip id */
>  	if (reg != BMP580_CHIP_ID && reg != BMP580_CHIP_ID_ALT)
> -		dev_warn(data->dev, "preinit: unexpected chip_id\n");
> +		dev_warn(data->dev, "unexpected chip_id\n");
>  
>  	ret = regmap_read(data->regmap, BMP580_REG_STATUS, &reg);
> -	if (ret)
> +	if (ret) {
> +		dev_err(data->dev, "failed to read nvm status\n");
>  		return ret;
> +	}
>  
>  	/* Check nvm status */
>  	if (!(reg & BMP580_STATUS_NVM_RDY_MASK) || (reg & BMP580_STATUS_NVM_ERR_MASK)) {
> -		dev_err(data->dev, "preinit: nvm error on powerup sequence\n");
> +		dev_err(data->dev, "nvm error on powerup sequence\n");
>  		return -EIO;
>  	}
>  
> @@ -1657,6 +1661,10 @@ static int bmp580_chip_config(struct bmp280_data *data)
>  				 BMP580_DSP_COMP_MASK |
>  				 BMP580_DSP_SHDW_IIR_TEMP_EN |
>  				 BMP580_DSP_SHDW_IIR_PRESS_EN, reg_val);
> +	if (ret) {
> +		dev_err(data->dev, "failed to change DSP mode settings\n");
> +		return ret;
> +	}
>  
>  	/* Configure oversampling */
>  	reg_val = FIELD_PREP(BMP580_OSR_TEMP_MASK, data->oversampling_temp) |
> @@ -1778,8 +1786,10 @@ static int bmp180_wait_for_eoc(struct bmp280_data *data, u8 ctrl_meas)
>  		reinit_completion(&data->done);
>  
>  	ret = regmap_write(data->regmap, BMP280_REG_CTRL_MEAS, ctrl_meas);
> -	if (ret)
> +	if (ret) {
> +		dev_err(data->dev, "failed to write crtl_meas register\n");
>  		return ret;
> +	}
>  
>  	if (data->use_eoc) {
>  		/*
> @@ -1802,12 +1812,16 @@ static int bmp180_wait_for_eoc(struct bmp280_data *data, u8 ctrl_meas)
>  	}
>  
>  	ret = regmap_read(data->regmap, BMP280_REG_CTRL_MEAS, &ctrl);
> -	if (ret)
> +	if (ret) {
> +		dev_err(data->dev, "failed to read ctrl_meas register\n");
>  		return ret;
> +	}
>  
>  	/* The value of this bit reset to "0" after conversion is complete */
> -	if (ctrl & BMP180_MEAS_SCO)
> +	if (ctrl & BMP180_MEAS_SCO) {
> +		dev_err(data->dev, "conversion didn't complete\n");
>  		return -EIO;
> +	}
>  
>  	return 0;
>  }
> @@ -1824,8 +1838,10 @@ static int bmp180_read_adc_temp(struct bmp280_data *data, int *val)
>  
>  	ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB,
>  			       &data->be16, sizeof(data->be16));
> -	if (ret)
> +	if (ret) {
> +		dev_err(data->dev, "failed to read temperature\n");
>  		return ret;
> +	}
>  
>  	*val = be16_to_cpu(data->be16);
>  
> @@ -1840,9 +1856,10 @@ static int bmp180_read_calib(struct bmp280_data *data)
>  
>  	ret = regmap_bulk_read(data->regmap, BMP180_REG_CALIB_START,
>  			       data->bmp180_cal_buf, sizeof(data->bmp180_cal_buf));
> -
> -	if (ret < 0)
> +	if (ret < 0) {
> +		dev_err(data->dev, "failed to read calibration parameters\n");
>  		return ret;
> +	}
>  
>  	/* None of the words has the value 0 or 0xFFFF */
>  	for (i = 0; i < ARRAY_SIZE(data->bmp180_cal_buf); i++) {
> @@ -1925,8 +1942,10 @@ static int bmp180_read_adc_press(struct bmp280_data *data, int *val)
>  
>  	ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB,
>  			       data->buf, sizeof(data->buf));
> -	if (ret)
> +	if (ret) {
> +		dev_err(data->dev, "failed to read pressure\n");
>  		return ret;
> +	}
>  
>  	*val = get_unaligned_be24(data->buf) >> (8 - oss);
>  
> @@ -2158,8 +2177,10 @@ int bmp280_common_probe(struct device *dev,
>  	data->regmap = regmap;
>  
>  	ret = regmap_read(regmap, data->chip_info->id_reg, &chip_id);
> -	if (ret < 0)
> +	if (ret < 0) {
> +		dev_err(data->dev, "failed to read chip id\n");
>  		return ret;
> +	}
>  
>  	for (i = 0; i < data->chip_info->num_chip_id; i++) {
>  		if (chip_id == data->chip_info->chip_id[i]) {

[PATCH v6 3/9] iio: pressure: bmp280: Make error checks consistent

[Vasileios Amoiridis]

The form 'if (ret)' is used in this driver in order to check
for returned error values. There are also some places that
'if (ret < 0)' is used but for no specific reason. Change
them to 'if (ret)' to make the driver more consistent.

Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
---
 drivers/iio/pressure/bmp280-core.c | 40 +++++++++++++++---------------
 1 file changed, 20 insertions(+), 20 deletions(-)

diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
index 0aa16fb135c1..f05ea754f53a 100644
--- a/drivers/iio/pressure/bmp280-core.c
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -184,7 +184,7 @@ static int bmp280_read_calib(struct bmp280_data *data)
 	ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_TEMP_START,
 			       data->bmp280_cal_buf,
 			       sizeof(data->bmp280_cal_buf));
-	if (ret < 0) {
+	if (ret) {
 		dev_err(data->dev,
 			"failed to read calibration parameters\n");
 		return ret;
@@ -222,7 +222,7 @@ static int bme280_read_calib(struct bmp280_data *data)
 
 	/* Load shared calibration params with bmp280 first */
 	ret = bmp280_read_calib(data);
-	if  (ret < 0)
+	if (ret)
 		return ret;
 
 	/*
@@ -234,7 +234,7 @@ static int bme280_read_calib(struct bmp280_data *data)
 	 */
 
 	ret = regmap_read(data->regmap, BME280_REG_COMP_H1, &tmp);
-	if (ret < 0) {
+	if (ret) {
 		dev_err(dev, "failed to read H1 comp value\n");
 		return ret;
 	}
@@ -242,14 +242,14 @@ static int bme280_read_calib(struct bmp280_data *data)
 
 	ret = regmap_bulk_read(data->regmap, BME280_REG_COMP_H2,
 			       &data->le16, sizeof(data->le16));
-	if (ret < 0) {
+	if (ret) {
 		dev_err(dev, "failed to read H2 comp value\n");
 		return ret;
 	}
 	calib->H2 = sign_extend32(le16_to_cpu(data->le16), 15);
 
 	ret = regmap_read(data->regmap, BME280_REG_COMP_H3, &tmp);
-	if (ret < 0) {
+	if (ret) {
 		dev_err(dev, "failed to read H3 comp value\n");
 		return ret;
 	}
@@ -257,7 +257,7 @@ static int bme280_read_calib(struct bmp280_data *data)
 
 	ret = regmap_bulk_read(data->regmap, BME280_REG_COMP_H4,
 			       &data->be16, sizeof(data->be16));
-	if (ret < 0) {
+	if (ret) {
 		dev_err(dev, "failed to read H4 comp value\n");
 		return ret;
 	}
@@ -266,14 +266,14 @@ static int bme280_read_calib(struct bmp280_data *data)
 
 	ret = regmap_bulk_read(data->regmap, BME280_REG_COMP_H5,
 			       &data->le16, sizeof(data->le16));
-	if (ret < 0) {
+	if (ret) {
 		dev_err(dev, "failed to read H5 comp value\n");
 		return ret;
 	}
 	calib->H5 = sign_extend32(FIELD_GET(BME280_COMP_H5_MASK, le16_to_cpu(data->le16)), 11);
 
 	ret = regmap_read(data->regmap, BME280_REG_COMP_H6, &tmp);
-	if (ret < 0) {
+	if (ret) {
 		dev_err(dev, "failed to read H6 comp value\n");
 		return ret;
 	}
@@ -370,7 +370,7 @@ static int bmp280_read_temp(struct bmp280_data *data,
 
 	ret = regmap_bulk_read(data->regmap, BMP280_REG_TEMP_MSB,
 			       data->buf, sizeof(data->buf));
-	if (ret < 0) {
+	if (ret) {
 		dev_err(data->dev, "failed to read temperature\n");
 		return ret;
 	}
@@ -404,12 +404,12 @@ static int bmp280_read_press(struct bmp280_data *data,
 
 	/* Read and compensate temperature so we get a reading of t_fine. */
 	ret = bmp280_read_temp(data, NULL, NULL);
-	if (ret < 0)
+	if (ret)
 		return ret;
 
 	ret = regmap_bulk_read(data->regmap, BMP280_REG_PRESS_MSB,
 			       data->buf, sizeof(data->buf));
-	if (ret < 0) {
+	if (ret) {
 		dev_err(data->dev, "failed to read pressure\n");
 		return ret;
 	}
@@ -436,12 +436,12 @@ static int bme280_read_humid(struct bmp280_data *data, int *val, int *val2)
 
 	/* Read and compensate temperature so we get a reading of t_fine. */
 	ret = bmp280_read_temp(data, NULL, NULL);
-	if (ret < 0)
+	if (ret)
 		return ret;
 
 	ret = regmap_bulk_read(data->regmap, BME280_REG_HUMIDITY_MSB,
 			       &data->be16, sizeof(data->be16));
-	if (ret < 0) {
+	if (ret) {
 		dev_err(data->dev, "failed to read humidity\n");
 		return ret;
 	}
@@ -775,7 +775,7 @@ static int bmp280_chip_config(struct bmp280_data *data)
 				BMP280_OSRS_PRESS_MASK |
 				BMP280_MODE_MASK,
 				osrs | BMP280_MODE_NORMAL);
-	if (ret < 0) {
+	if (ret) {
 		dev_err(data->dev, "failed to write ctrl_meas register\n");
 		return ret;
 	}
@@ -783,7 +783,7 @@ static int bmp280_chip_config(struct bmp280_data *data)
 	ret = regmap_update_bits(data->regmap, BMP280_REG_CONFIG,
 				 BMP280_FILTER_MASK,
 				 BMP280_FILTER_4X);
-	if (ret < 0) {
+	if (ret) {
 		dev_err(data->dev, "failed to write config register\n");
 		return ret;
 	}
@@ -839,7 +839,7 @@ static int bme280_chip_config(struct bmp280_data *data)
 	 */
 	ret = regmap_update_bits(data->regmap, BME280_REG_CTRL_HUMIDITY,
 				 BME280_OSRS_HUMIDITY_MASK, osrs);
-	if (ret < 0) {
+	if (ret) {
 		dev_err(data->dev, "failed to set humidity oversampling");
 		return ret;
 	}
@@ -1856,7 +1856,7 @@ static int bmp180_read_calib(struct bmp280_data *data)
 
 	ret = regmap_bulk_read(data->regmap, BMP180_REG_CALIB_START,
 			       data->bmp180_cal_buf, sizeof(data->bmp180_cal_buf));
-	if (ret < 0) {
+	if (ret) {
 		dev_err(data->dev, "failed to read calibration parameters\n");
 		return ret;
 	}
@@ -2177,7 +2177,7 @@ int bmp280_common_probe(struct device *dev,
 	data->regmap = regmap;
 
 	ret = regmap_read(regmap, data->chip_info->id_reg, &chip_id);
-	if (ret < 0) {
+	if (ret) {
 		dev_err(data->dev, "failed to read chip id\n");
 		return ret;
 	}
@@ -2200,7 +2200,7 @@ int bmp280_common_probe(struct device *dev,
 	}
 
 	ret = data->chip_info->chip_config(data);
-	if (ret < 0)
+	if (ret)
 		return ret;
 
 	dev_set_drvdata(dev, indio_dev);
@@ -2213,7 +2213,7 @@ int bmp280_common_probe(struct device *dev,
 
 	if (data->chip_info->read_calib) {
 		ret = data->chip_info->read_calib(data);
-		if (ret < 0)
+		if (ret)
 			return dev_err_probe(data->dev, ret,
 					     "failed to read calibration coefficients\n");
 	}
-- 
2.25.1

Re: [PATCH v6 3/9] iio: pressure: bmp280: Make error checks consistent

[Jonathan Cameron]

On Wed,  8 May 2024 18:52:01 +0200
Vasileios Amoiridis <vassilisamir@gmail.com> wrote:

> The form 'if (ret)' is used in this driver in order to check
> for returned error values. There are also some places that
> 'if (ret < 0)' is used but for no specific reason. Change
> them to 'if (ret)' to make the driver more consistent.
> 
> Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
Applied.

Thanks,

[PATCH v6 4/9] iio: pressure: bmp280: Use unsigned data types for raw sensor data

[Vasileios Amoiridis]

The raw sensor data that have not been compensated yet cannot be
signed values, so use unsigned ones. Also, compensated pressure
values cannot be negative so use unsigned also there.

Also, drop redundant cast of data->t_fine variable from s32 to s32.

Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
---
 drivers/iio/pressure/bmp280-core.c | 45 +++++++++++++++---------------
 1 file changed, 22 insertions(+), 23 deletions(-)

diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
index f05ea754f53a..dd5c526dacbd 100644
--- a/drivers/iio/pressure/bmp280-core.c
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -289,13 +289,13 @@ static int bme280_read_calib(struct bmp280_data *data)
  * Taken from BME280 datasheet, Section 4.2.3, "Compensation formula".
  */
 static u32 bme280_compensate_humidity(struct bmp280_data *data,
-				      s32 adc_humidity)
+				      u16 adc_humidity)
 {
 	struct bmp280_calib *calib = &data->calib.bmp280;
 	s32 var;
 
-	var = ((s32)data->t_fine) - (s32)76800;
-	var = ((((adc_humidity << 14) - (calib->H4 << 20) - (calib->H5 * var))
+	var = data->t_fine - (s32)76800;
+	var = (((((s32)adc_humidity << 14) - (calib->H4 << 20) - (calib->H5 * var))
 		+ (s32)16384) >> 15) * (((((((var * calib->H6) >> 10)
 		* (((var * (s32)calib->H3) >> 11) + (s32)32768)) >> 10)
 		+ (s32)2097152) * calib->H2 + 8192) >> 14);
@@ -314,16 +314,16 @@ static u32 bme280_compensate_humidity(struct bmp280_data *data,
  * Taken from datasheet, Section 3.11.3, "Compensation formula".
  */
 static s32 bmp280_compensate_temp(struct bmp280_data *data,
-				  s32 adc_temp)
+				  u32 adc_temp)
 {
 	struct bmp280_calib *calib = &data->calib.bmp280;
 	s32 var1, var2;
 
-	var1 = (((adc_temp >> 3) - ((s32)calib->T1 << 1)) *
+	var1 = (((((s32)adc_temp) >> 3) - ((s32)calib->T1 << 1)) *
 		((s32)calib->T2)) >> 11;
-	var2 = (((((adc_temp >> 4) - ((s32)calib->T1)) *
-		  ((adc_temp >> 4) - ((s32)calib->T1))) >> 12) *
-		((s32)calib->T3)) >> 14;
+	var2 = (((((((s32)adc_temp) >> 4) - ((s32)calib->T1)) *
+		  ((((s32)adc_temp >> 4) - ((s32)calib->T1))) >> 12) *
+		((s32)calib->T3))) >> 14;
 	data->t_fine = var1 + var2;
 
 	return (data->t_fine * 5 + 128) >> 8;
@@ -337,7 +337,7 @@ static s32 bmp280_compensate_temp(struct bmp280_data *data,
  * Taken from datasheet, Section 3.11.3, "Compensation formula".
  */
 static u32 bmp280_compensate_press(struct bmp280_data *data,
-				   s32 adc_press)
+				   u32 adc_press)
 {
 	struct bmp280_calib *calib = &data->calib.bmp280;
 	s64 var1, var2, p;
@@ -353,7 +353,7 @@ static u32 bmp280_compensate_press(struct bmp280_data *data,
 	if (var1 == 0)
 		return 0;
 
-	p = ((((s64)1048576 - adc_press) << 31) - var2) * 3125;
+	p = ((((s64)1048576 - (s32)adc_press) << 31) - var2) * 3125;
 	p = div64_s64(p, var1);
 	var1 = (((s64)calib->P9) * (p >> 13) * (p >> 13)) >> 25;
 	var2 = ((s64)(calib->P8) * p) >> 19;
@@ -365,7 +365,8 @@ static u32 bmp280_compensate_press(struct bmp280_data *data,
 static int bmp280_read_temp(struct bmp280_data *data,
 			    int *val, int *val2)
 {
-	s32 adc_temp, comp_temp;
+	s32 comp_temp;
+	u32 adc_temp;
 	int ret;
 
 	ret = regmap_bulk_read(data->regmap, BMP280_REG_TEMP_MSB,
@@ -398,8 +399,7 @@ static int bmp280_read_temp(struct bmp280_data *data,
 static int bmp280_read_press(struct bmp280_data *data,
 			     int *val, int *val2)
 {
-	u32 comp_press;
-	s32 adc_press;
+	u32 comp_press, adc_press;
 	int ret;
 
 	/* Read and compensate temperature so we get a reading of t_fine. */
@@ -431,7 +431,7 @@ static int bmp280_read_press(struct bmp280_data *data,
 static int bme280_read_humid(struct bmp280_data *data, int *val, int *val2)
 {
 	u32 comp_humidity;
-	s32 adc_humidity;
+	u16 adc_humidity;
 	int ret;
 
 	/* Read and compensate temperature so we get a reading of t_fine. */
@@ -1030,8 +1030,7 @@ static int bmp380_read_temp(struct bmp280_data *data, int *val, int *val2)
 
 static int bmp380_read_press(struct bmp280_data *data, int *val, int *val2)
 {
-	s32 comp_press;
-	u32 adc_press;
+	u32 adc_press, comp_press;
 	int ret;
 
 	/* Read and compensate for temperature so we get a reading of t_fine */
@@ -1893,12 +1892,12 @@ static int bmp180_read_calib(struct bmp280_data *data)
  *
  * Taken from datasheet, Section 3.5, "Calculating pressure and temperature".
  */
-static s32 bmp180_compensate_temp(struct bmp280_data *data, s32 adc_temp)
+static s32 bmp180_compensate_temp(struct bmp280_data *data, u32 adc_temp)
 {
 	struct bmp180_calib *calib = &data->calib.bmp180;
 	s32 x1, x2;
 
-	x1 = ((adc_temp - calib->AC6) * calib->AC5) >> 15;
+	x1 = ((((s32)adc_temp) - calib->AC6) * calib->AC5) >> 15;
 	x2 = (calib->MC << 11) / (x1 + calib->MD);
 	data->t_fine = x1 + x2;
 
@@ -1907,7 +1906,8 @@ static s32 bmp180_compensate_temp(struct bmp280_data *data, s32 adc_temp)
 
 static int bmp180_read_temp(struct bmp280_data *data, int *val, int *val2)
 {
-	s32 adc_temp, comp_temp;
+	s32 comp_temp;
+	u32 adc_temp;
 	int ret;
 
 	ret = bmp180_read_adc_temp(data, &adc_temp);
@@ -1957,7 +1957,7 @@ static int bmp180_read_adc_press(struct bmp280_data *data, int *val)
  *
  * Taken from datasheet, Section 3.5, "Calculating pressure and temperature".
  */
-static u32 bmp180_compensate_press(struct bmp280_data *data, s32 adc_press)
+static u32 bmp180_compensate_press(struct bmp280_data *data, u32 adc_press)
 {
 	struct bmp180_calib *calib = &data->calib.bmp180;
 	s32 oss = data->oversampling_press;
@@ -1974,7 +1974,7 @@ static u32 bmp180_compensate_press(struct bmp280_data *data, s32 adc_press)
 	x2 = (calib->B1 * ((b6 * b6) >> 12)) >> 16;
 	x3 = (x1 + x2 + 2) >> 2;
 	b4 = calib->AC4 * (u32)(x3 + 32768) >> 15;
-	b7 = ((u32)adc_press - b3) * (50000 >> oss);
+	b7 = (adc_press - b3) * (50000 >> oss);
 	if (b7 < 0x80000000)
 		p = (b7 * 2) / b4;
 	else
@@ -1989,8 +1989,7 @@ static u32 bmp180_compensate_press(struct bmp280_data *data, s32 adc_press)
 
 static int bmp180_read_press(struct bmp280_data *data, int *val, int *val2)
 {
-	u32 comp_press;
-	s32 adc_press;
+	u32 comp_press, adc_press;
 	int ret;
 
 	/* Read and compensate temperature so we get a reading of t_fine. */
-- 
2.25.1

Re: [PATCH v6 4/9] iio: pressure: bmp280: Use unsigned data types for raw sensor data

[Jonathan Cameron]

On Wed,  8 May 2024 18:52:02 +0200
Vasileios Amoiridis <vassilisamir@gmail.com> wrote:

> The raw sensor data that have not been compensated yet cannot be
> signed values, so use unsigned ones. Also, compensated pressure
> values cannot be negative so use unsigned also there.
> 
> Also, drop redundant cast of data->t_fine variable from s32 to s32.
> 
> Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
Looks good to me.

Applied.

[PATCH v6 5/9] iio: pressure: bmp280: Refactorize reading functions

[Vasileios Amoiridis]

For BMP18x, BMP28x, BME280, BMP38x the reading of the pressure
value requires an update of the t_fine variable which happens
through reading the temperature value.

So all the bmpxxx_read_press() functions of the above sensors
are internally calling the equivalent bmpxxx_read_temp() function
in order to update the t_fine value. By just looking at the code
this functionality is a bit hidden and is not easy to understand
why those channels are not independent.

This commit tries to clear these things a bit by splitting the
bmpxxx_{read/compensate}_{temp/press/humid}() to the following:

i. bmpxxx_read_{temp/press/humid}_adc(): read the raw value from
the sensor.

ii. bmpxx_calc_t_fine(): calculate the t_fine variable.

iii. bmpxxx_get_t_fine(): get the t_fine variable.

iv. bmpxxx_compensate_{temp/press/humid}(): compensate the adc
values and return the calculated value.

v. bmpxxx_read_{temp/press/humid}(): combine calls of the
aforementioned functions to return the requested value.

Suggested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
---
 drivers/iio/pressure/bmp280-core.c | 361 ++++++++++++++++++-----------
 drivers/iio/pressure/bmp280.h      |   6 -
 2 files changed, 232 insertions(+), 135 deletions(-)

diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
index dd5c526dacbd..a864f8db8e24 100644
--- a/drivers/iio/pressure/bmp280-core.c
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -288,13 +288,35 @@ static int bme280_read_calib(struct bmp280_data *data)
  *
  * Taken from BME280 datasheet, Section 4.2.3, "Compensation formula".
  */
+static int bme280_read_humid_adc(struct bmp280_data *data, u16 *adc_humidity)
+{
+	u16 value_humidity;
+	int ret;
+
+	ret = regmap_bulk_read(data->regmap, BME280_REG_HUMIDITY_MSB,
+			       &data->be16, sizeof(data->be16));
+	if (ret) {
+		dev_err(data->dev, "failed to read humidity\n");
+		return ret;
+	}
+
+	value_humidity = be16_to_cpu(data->be16);
+	if (value_humidity == BMP280_HUMIDITY_SKIPPED) {
+		dev_err(data->dev, "reading humidity skipped\n");
+		return -EIO;
+	}
+	*adc_humidity = value_humidity;
+
+	return 0;
+}
+
 static u32 bme280_compensate_humidity(struct bmp280_data *data,
-				      u16 adc_humidity)
+				      u16 adc_humidity, s32 t_fine)
 {
 	struct bmp280_calib *calib = &data->calib.bmp280;
 	s32 var;
 
-	var = data->t_fine - (s32)76800;
+	var = t_fine - (s32)76800;
 	var = (((((s32)adc_humidity << 14) - (calib->H4 << 20) - (calib->H5 * var))
 		+ (s32)16384) >> 15) * (((((((var * calib->H6) >> 10)
 		* (((var * (s32)calib->H3) >> 11) + (s32)32768)) >> 10)
@@ -313,8 +335,29 @@ static u32 bme280_compensate_humidity(struct bmp280_data *data,
  *
  * Taken from datasheet, Section 3.11.3, "Compensation formula".
  */
-static s32 bmp280_compensate_temp(struct bmp280_data *data,
-				  u32 adc_temp)
+static int bmp280_read_temp_adc(struct bmp280_data *data, u32 *adc_temp)
+{
+	u32 value_temp;
+	int ret;
+
+	ret = regmap_bulk_read(data->regmap, BMP280_REG_TEMP_MSB,
+			       data->buf, sizeof(data->buf));
+	if (ret) {
+		dev_err(data->dev, "failed to read temperature\n");
+		return ret;
+	}
+
+	value_temp = FIELD_GET(BMP280_MEAS_TRIM_MASK, get_unaligned_be24(data->buf));
+	if (value_temp == BMP280_TEMP_SKIPPED) {
+		dev_err(data->dev, "reading temperature skipped\n");
+		return -EIO;
+	}
+	*adc_temp = value_temp;
+
+	return 0;
+}
+
+static s32 bmp280_calc_t_fine(struct bmp280_data *data, u32 adc_temp)
 {
 	struct bmp280_calib *calib = &data->calib.bmp280;
 	s32 var1, var2;
@@ -324,9 +367,26 @@ static s32 bmp280_compensate_temp(struct bmp280_data *data,
 	var2 = (((((((s32)adc_temp) >> 4) - ((s32)calib->T1)) *
 		  ((((s32)adc_temp >> 4) - ((s32)calib->T1))) >> 12) *
 		((s32)calib->T3))) >> 14;
-	data->t_fine = var1 + var2;
+	return var1 + var2; /* t_fine = var1 + var2 */
+}
+
+static int bmp280_get_t_fine(struct bmp280_data *data, s32 *t_fine)
+{
+	u32 adc_temp;
+	int ret;
+
+	ret = bmp280_read_temp_adc(data, &adc_temp);
+	if (ret)
+		return ret;
 
-	return (data->t_fine * 5 + 128) >> 8;
+	*t_fine = bmp280_calc_t_fine(data, adc_temp);
+
+	return 0;
+}
+
+static s32 bmp280_compensate_temp(struct bmp280_data *data, u32 adc_temp)
+{
+	return (bmp280_calc_t_fine(data, adc_temp) * 5 + 128) / 256;
 }
 
 /*
@@ -336,13 +396,35 @@ static s32 bmp280_compensate_temp(struct bmp280_data *data,
  *
  * Taken from datasheet, Section 3.11.3, "Compensation formula".
  */
+static int bmp280_read_press_adc(struct bmp280_data *data, u32 *adc_press)
+{
+	u32 value_press;
+	int ret;
+
+	ret = regmap_bulk_read(data->regmap, BMP280_REG_PRESS_MSB,
+			       data->buf, sizeof(data->buf));
+	if (ret) {
+		dev_err(data->dev, "failed to read pressure\n");
+		return ret;
+	}
+
+	value_press = FIELD_GET(BMP280_MEAS_TRIM_MASK, get_unaligned_be24(data->buf));
+	if (value_press == BMP280_PRESS_SKIPPED) {
+		dev_err(data->dev, "reading pressure skipped\n");
+		return -EIO;
+	}
+	*adc_press = value_press;
+
+	return 0;
+}
+
 static u32 bmp280_compensate_press(struct bmp280_data *data,
-				   u32 adc_press)
+				   u32 adc_press, s32 t_fine)
 {
 	struct bmp280_calib *calib = &data->calib.bmp280;
 	s64 var1, var2, p;
 
-	var1 = ((s64)data->t_fine) - 128000;
+	var1 = ((s64)t_fine) - 128000;
 	var2 = var1 * var1 * (s64)calib->P6;
 	var2 += (var1 * (s64)calib->P5) << 17;
 	var2 += ((s64)calib->P4) << 35;
@@ -369,59 +451,34 @@ static int bmp280_read_temp(struct bmp280_data *data,
 	u32 adc_temp;
 	int ret;
 
-	ret = regmap_bulk_read(data->regmap, BMP280_REG_TEMP_MSB,
-			       data->buf, sizeof(data->buf));
-	if (ret) {
-		dev_err(data->dev, "failed to read temperature\n");
+	ret = bmp280_read_temp_adc(data, &adc_temp);
+	if (ret)
 		return ret;
-	}
 
-	adc_temp = FIELD_GET(BMP280_MEAS_TRIM_MASK, get_unaligned_be24(data->buf));
-	if (adc_temp == BMP280_TEMP_SKIPPED) {
-		/* reading was skipped */
-		dev_err(data->dev, "reading temperature skipped\n");
-		return -EIO;
-	}
 	comp_temp = bmp280_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) {
-		*val = comp_temp * 10;
-		return IIO_VAL_INT;
-	}
-
-	return 0;
+	/* IIO units are in milli Celsius */
+	*val = comp_temp * 10;
+	return IIO_VAL_INT;
 }
 
 static int bmp280_read_press(struct bmp280_data *data,
 			     int *val, int *val2)
 {
-	u32 comp_press, adc_press;
+	u32 comp_press, adc_press, t_fine;
 	int ret;
 
-	/* Read and compensate temperature so we get a reading of t_fine. */
-	ret = bmp280_read_temp(data, NULL, NULL);
+	ret = bmp280_get_t_fine(data, &t_fine);
 	if (ret)
 		return ret;
 
-	ret = regmap_bulk_read(data->regmap, BMP280_REG_PRESS_MSB,
-			       data->buf, sizeof(data->buf));
-	if (ret) {
-		dev_err(data->dev, "failed to read pressure\n");
+	ret = bmp280_read_press_adc(data, &adc_press);
+	if (ret)
 		return ret;
-	}
 
-	adc_press = FIELD_GET(BMP280_MEAS_TRIM_MASK, get_unaligned_be24(data->buf));
-	if (adc_press == BMP280_PRESS_SKIPPED) {
-		/* reading was skipped */
-		dev_err(data->dev, "reading pressure skipped\n");
-		return -EIO;
-	}
-	comp_press = bmp280_compensate_press(data, adc_press);
+	comp_press = bmp280_compensate_press(data, adc_press, t_fine);
 
+	/* IIO units are in kPa */
 	*val = comp_press;
 	*val2 = 256000;
 
@@ -432,28 +489,20 @@ static int bme280_read_humid(struct bmp280_data *data, int *val, int *val2)
 {
 	u32 comp_humidity;
 	u16 adc_humidity;
+	s32 t_fine;
 	int ret;
 
-	/* Read and compensate temperature so we get a reading of t_fine. */
-	ret = bmp280_read_temp(data, NULL, NULL);
+	ret = bmp280_get_t_fine(data, &t_fine);
 	if (ret)
 		return ret;
 
-	ret = regmap_bulk_read(data->regmap, BME280_REG_HUMIDITY_MSB,
-			       &data->be16, sizeof(data->be16));
-	if (ret) {
-		dev_err(data->dev, "failed to read humidity\n");
+	ret = bme280_read_humid_adc(data, &adc_humidity);
+	if (ret)
 		return ret;
-	}
 
-	adc_humidity = be16_to_cpu(data->be16);
-	if (adc_humidity == BMP280_HUMIDITY_SKIPPED) {
-		/* reading was skipped */
-		dev_err(data->dev, "reading humidity skipped\n");
-		return -EIO;
-	}
-	comp_humidity = bme280_compensate_humidity(data, adc_humidity);
+	comp_humidity = bme280_compensate_humidity(data, adc_humidity, t_fine);
 
+	/* IIO units are in 1000 * % */
 	*val = comp_humidity * 1000 / 1024;
 
 	return IIO_VAL_INT;
@@ -930,9 +979,31 @@ static int bmp380_cmd(struct bmp280_data *data, u8 cmd)
  * 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)
+static int bmp380_read_temp_adc(struct bmp280_data *data, u32 *adc_temp)
+{
+	u32 value_temp;
+	int ret;
+
+	ret = regmap_bulk_read(data->regmap, BMP380_REG_TEMP_XLSB,
+			       data->buf, sizeof(data->buf));
+	if (ret) {
+		dev_err(data->dev, "failed to read temperature\n");
+		return ret;
+	}
+
+	value_temp = get_unaligned_le24(data->buf);
+	if (value_temp == BMP380_TEMP_SKIPPED) {
+		dev_err(data->dev, "reading temperature skipped\n");
+		return -EIO;
+	}
+	*adc_temp = value_temp;
+
+	return 0;
+}
+
+static s32 bmp380_calc_t_fine(struct bmp280_data *data, u32 adc_temp)
 {
-	s64 var1, var2, var3, var4, var5, var6, comp_temp;
+	s64 var1, var2, var3, var4, var5, var6;
 	struct bmp380_calib *calib = &data->calib.bmp380;
 
 	var1 = ((s64) adc_temp) - (((s64) calib->T1) << 8);
@@ -941,7 +1012,29 @@ static s32 bmp380_compensate_temp(struct bmp280_data *data, u32 adc_temp)
 	var4 = var3 * ((s64) calib->T3);
 	var5 = (var2 << 18) + var4;
 	var6 = var5 >> 32;
-	data->t_fine = (s32) var6;
+	return (s32) var6; /* t_fine = var6 */
+}
+
+static int bmp380_get_t_fine(struct bmp280_data *data, s32 *t_fine)
+{
+	s32 adc_temp;
+	int ret;
+
+	ret = bmp380_read_temp_adc(data, &adc_temp);
+	if (ret)
+		return ret;
+
+	*t_fine = bmp380_calc_t_fine(data, adc_temp);
+
+	return 0;
+}
+
+static int bmp380_compensate_temp(struct bmp280_data *data, u32 adc_temp)
+{
+	s64 comp_temp;
+	s32 var6;
+
+	var6 = bmp380_calc_t_fine(data, adc_temp);
 	comp_temp = (var6 * 25) >> 14;
 
 	comp_temp = clamp_val(comp_temp, BMP380_MIN_TEMP, BMP380_MAX_TEMP);
@@ -955,27 +1048,50 @@ static s32 bmp380_compensate_temp(struct bmp280_data *data, u32 adc_temp)
  * 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)
+static int bmp380_read_press_adc(struct bmp280_data *data, u32 *adc_press)
+{
+	u32 value_press;
+	int ret;
+
+	ret = regmap_bulk_read(data->regmap, BMP380_REG_PRESS_XLSB,
+			       data->buf, sizeof(data->buf));
+	if (ret) {
+		dev_err(data->dev, "failed to read pressure\n");
+		return ret;
+	}
+
+	value_press = get_unaligned_le24(data->buf);
+	if (value_press == BMP380_PRESS_SKIPPED) {
+		dev_err(data->dev, "reading pressure skipped\n");
+		return -EIO;
+	}
+	*adc_press = value_press;
+
+	return 0;
+}
+
+static u32 bmp380_compensate_press(struct bmp280_data *data,
+				   u32 adc_press, s32 t_fine)
 {
 	s64 var1, var2, var3, var4, var5, var6, offset, sensitivity;
 	struct bmp380_calib *calib = &data->calib.bmp380;
 	u32 comp_press;
 
-	var1 = (s64)data->t_fine * (s64)data->t_fine;
+	var1 = (s64)t_fine * (s64)t_fine;
 	var2 = var1 >> 6;
-	var3 = (var2 * ((s64) data->t_fine)) >> 8;
+	var3 = (var2 * ((s64) t_fine)) >> 8;
 	var4 = ((s64)calib->P8 * var3) >> 5;
 	var5 = ((s64)calib->P7 * var1) << 4;
-	var6 = ((s64)calib->P6 * (s64)data->t_fine) << 22;
+	var6 = ((s64)calib->P6 * (s64)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);
+	       ((s64)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;
+	var2 = (s64)calib->P10 * (s64)t_fine;
 	var3 = var2 + ((s64)calib->P9 << 16);
 	var4 = (var3 * (s64)adc_press) >> 13;
 
@@ -1001,59 +1117,34 @@ static int bmp380_read_temp(struct bmp280_data *data, int *val, int *val2)
 	u32 adc_temp;
 	int ret;
 
-	ret = regmap_bulk_read(data->regmap, BMP380_REG_TEMP_XLSB,
-			       data->buf, sizeof(data->buf));
-	if (ret) {
-		dev_err(data->dev, "failed to read temperature\n");
+	ret = bmp380_read_temp_adc(data, &adc_temp);
+	if (ret)
 		return ret;
-	}
 
-	adc_temp = get_unaligned_le24(data->buf);
-	if (adc_temp == BMP380_TEMP_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 milli Celsius */
-		*val = comp_temp * 10;
-		return IIO_VAL_INT;
-	}
-
-	return 0;
+	/* IIO units are in milli Celsius */
+	*val = comp_temp * 10;
+	return IIO_VAL_INT;
 }
 
 static int bmp380_read_press(struct bmp280_data *data, int *val, int *val2)
 {
-	u32 adc_press, comp_press;
+	u32 adc_press, comp_press, t_fine;
 	int ret;
 
-	/* Read and compensate for temperature so we get a reading of t_fine */
-	ret = bmp380_read_temp(data, NULL, NULL);
+	ret = bmp380_get_t_fine(data, &t_fine);
 	if (ret)
 		return ret;
 
-	ret = regmap_bulk_read(data->regmap, BMP380_REG_PRESS_XLSB,
-			       data->buf, sizeof(data->buf));
-	if (ret) {
-		dev_err(data->dev, "failed to read pressure\n");
+	ret = bmp380_read_press_adc(data, &adc_press);
+	if (ret)
 		return ret;
-	}
 
-	adc_press = get_unaligned_le24(data->buf);
-	if (adc_press == BMP380_PRESS_SKIPPED) {
-		dev_err(data->dev, "reading pressure skipped\n");
-		return -EIO;
-	}
-	comp_press = bmp380_compensate_press(data, adc_press);
+	comp_press = bmp380_compensate_press(data, adc_press, t_fine);
 
+	/* IIO units are in kPa */
 	*val = comp_press;
-	/* Compensated pressure is in cPa (centipascals) */
 	*val2 = 100000;
 
 	return IIO_VAL_FRACTIONAL;
@@ -1825,7 +1916,7 @@ static int bmp180_wait_for_eoc(struct bmp280_data *data, u8 ctrl_meas)
 	return 0;
 }
 
-static int bmp180_read_adc_temp(struct bmp280_data *data, int *val)
+static int bmp180_read_temp_adc(struct bmp280_data *data, u32 *adc_temp)
 {
 	int ret;
 
@@ -1842,7 +1933,7 @@ static int bmp180_read_adc_temp(struct bmp280_data *data, int *val)
 		return ret;
 	}
 
-	*val = be16_to_cpu(data->be16);
+	*adc_temp = be16_to_cpu(data->be16);
 
 	return 0;
 }
@@ -1892,16 +1983,34 @@ static int bmp180_read_calib(struct bmp280_data *data)
  *
  * Taken from datasheet, Section 3.5, "Calculating pressure and temperature".
  */
-static s32 bmp180_compensate_temp(struct bmp280_data *data, u32 adc_temp)
+
+static s32 bmp180_calc_t_fine(struct bmp280_data *data, u32 adc_temp)
 {
 	struct bmp180_calib *calib = &data->calib.bmp180;
 	s32 x1, x2;
 
 	x1 = ((((s32)adc_temp) - calib->AC6) * calib->AC5) >> 15;
 	x2 = (calib->MC << 11) / (x1 + calib->MD);
-	data->t_fine = x1 + x2;
+	return x1 + x2; /* t_fine = x1 + x2; */
+}
+
+static int bmp180_get_t_fine(struct bmp280_data *data, s32 *t_fine)
+{
+	s32 adc_temp;
+	int ret;
+
+	ret = bmp180_read_temp_adc(data, &adc_temp);
+	if (ret)
+		return ret;
+
+	*t_fine = bmp180_calc_t_fine(data, adc_temp);
 
-	return (data->t_fine + 8) >> 4;
+	return 0;
+}
+
+static s32 bmp180_compensate_temp(struct bmp280_data *data, u32 adc_temp)
+{
+	return (bmp180_calc_t_fine(data, adc_temp) + 8) / 16;
 }
 
 static int bmp180_read_temp(struct bmp280_data *data, int *val, int *val2)
@@ -1910,25 +2019,18 @@ static int bmp180_read_temp(struct bmp280_data *data, int *val, int *val2)
 	u32 adc_temp;
 	int ret;
 
-	ret = bmp180_read_adc_temp(data, &adc_temp);
+	ret = bmp180_read_temp_adc(data, &adc_temp);
 	if (ret)
 		return ret;
 
 	comp_temp = bmp180_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) {
-		*val = comp_temp * 100;
-		return IIO_VAL_INT;
-	}
-
-	return 0;
+	/* IIO units are in milli Celsius */
+	*val = comp_temp * 100;
+	return IIO_VAL_INT;
 }
 
-static int bmp180_read_adc_press(struct bmp280_data *data, int *val)
+static int bmp180_read_press_adc(struct bmp280_data *data, u32 *adc_press)
 {
 	u8 oss = data->oversampling_press;
 	int ret;
@@ -1947,7 +2049,7 @@ static int bmp180_read_adc_press(struct bmp280_data *data, int *val)
 		return ret;
 	}
 
-	*val = get_unaligned_be24(data->buf) >> (8 - oss);
+	*adc_press = get_unaligned_be24(data->buf) >> (8 - oss);
 
 	return 0;
 }
@@ -1957,7 +2059,8 @@ static int bmp180_read_adc_press(struct bmp280_data *data, int *val)
  *
  * Taken from datasheet, Section 3.5, "Calculating pressure and temperature".
  */
-static u32 bmp180_compensate_press(struct bmp280_data *data, u32 adc_press)
+static u32 bmp180_compensate_press(struct bmp280_data *data, u32 adc_press,
+				   s32 t_fine)
 {
 	struct bmp180_calib *calib = &data->calib.bmp180;
 	s32 oss = data->oversampling_press;
@@ -1965,7 +2068,7 @@ static u32 bmp180_compensate_press(struct bmp280_data *data, u32 adc_press)
 	s32 b3, b6;
 	u32 b4, b7;
 
-	b6 = data->t_fine - 4000;
+	b6 = t_fine - 4000;
 	x1 = (calib->B2 * (b6 * b6 >> 12)) >> 11;
 	x2 = calib->AC2 * b6 >> 11;
 	x3 = x1 + x2;
@@ -1974,7 +2077,7 @@ static u32 bmp180_compensate_press(struct bmp280_data *data, u32 adc_press)
 	x2 = (calib->B1 * ((b6 * b6) >> 12)) >> 16;
 	x3 = (x1 + x2 + 2) >> 2;
 	b4 = calib->AC4 * (u32)(x3 + 32768) >> 15;
-	b7 = (adc_press - b3) * (50000 >> oss);
+	b7 = (((u32)adc_press) - b3) * (50000 >> oss);
 	if (b7 < 0x80000000)
 		p = (b7 * 2) / b4;
 	else
@@ -1990,19 +2093,19 @@ static u32 bmp180_compensate_press(struct bmp280_data *data, u32 adc_press)
 static int bmp180_read_press(struct bmp280_data *data, int *val, int *val2)
 {
 	u32 comp_press, adc_press;
-	int ret;
+	s32 t_fine;
 
-	/* Read and compensate temperature so we get a reading of t_fine. */
-	ret = bmp180_read_temp(data, NULL, NULL);
+	ret = bmp180_get_t_fine(data, &t_fine);
 	if (ret)
 		return ret;
 
-	ret = bmp180_read_adc_press(data, &adc_press);
+	ret = bmp180_read_press_adc(data, &adc_press);
 	if (ret)
 		return ret;
 
-	comp_press = bmp180_compensate_press(data, adc_press);
+	comp_press = bmp180_compensate_press(data, adc_press, t_fine);
 
+	/* IIO units are in kPa */
 	*val = comp_press;
 	*val2 = 1000;
 
diff --git a/drivers/iio/pressure/bmp280.h b/drivers/iio/pressure/bmp280.h
index fe4d3f127954..7c30e4d523be 100644
--- a/drivers/iio/pressure/bmp280.h
+++ b/drivers/iio/pressure/bmp280.h
@@ -397,12 +397,6 @@ struct bmp280_data {
 	 */
 	int sampling_freq;
 
-	/*
-	 * Carryover value from temperature conversion, used in pressure
-	 * calculation.
-	 */
-	s32 t_fine;
-
 	/*
 	 * DMA (thus cache coherency maintenance) may require the
 	 * transfer buffers to live in their own cache lines.
-- 
2.25.1

Re: [PATCH v6 5/9] iio: pressure: bmp280: Refactorize reading functions

[Jonathan Cameron]

On Wed,  8 May 2024 18:52:03 +0200
Vasileios Amoiridis <vassilisamir@gmail.com> wrote:

> For BMP18x, BMP28x, BME280, BMP38x the reading of the pressure
> value requires an update of the t_fine variable which happens
> through reading the temperature value.
> 
> So all the bmpxxx_read_press() functions of the above sensors
> are internally calling the equivalent bmpxxx_read_temp() function
> in order to update the t_fine value. By just looking at the code
> this functionality is a bit hidden and is not easy to understand
> why those channels are not independent.
> 
> This commit tries to clear these things a bit by splitting the
> bmpxxx_{read/compensate}_{temp/press/humid}() to the following:
> 
> i. bmpxxx_read_{temp/press/humid}_adc(): read the raw value from
> the sensor.
> 
> ii. bmpxx_calc_t_fine(): calculate the t_fine variable.
> 
> iii. bmpxxx_get_t_fine(): get the t_fine variable.
> 
> iv. bmpxxx_compensate_{temp/press/humid}(): compensate the adc
> values and return the calculated value.
> 
> v. bmpxxx_read_{temp/press/humid}(): combine calls of the
> aforementioned functions to return the requested value.
> 
> Suggested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
A few minor things inline.  Given I've picked up the 1st 4 patches,
please base your v7 on top of those.

Thanks,

Jonathan

> ---
>  drivers/iio/pressure/bmp280-core.c | 361 ++++++++++++++++++-----------
>  drivers/iio/pressure/bmp280.h      |   6 -
>  2 files changed, 232 insertions(+), 135 deletions(-)
> 
> diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
> index dd5c526dacbd..a864f8db8e24 100644
> --- a/drivers/iio/pressure/bmp280-core.c
> +++ b/drivers/iio/pressure/bmp280-core.c
> @@ -288,13 +288,35 @@ static int bme280_read_calib(struct bmp280_data *data)
>   *
>   * Taken from BME280 datasheet, Section 4.2.3, "Compensation formula".
>   */

Seems this comment should probably follow the maths which has moved.

> +static int bme280_read_humid_adc(struct bmp280_data *data, u16 *adc_humidity)
> +{
> +	u16 value_humidity;
> +	int ret;
> +
> +	ret = regmap_bulk_read(data->regmap, BME280_REG_HUMIDITY_MSB,
> +			       &data->be16, sizeof(data->be16));
> +	if (ret) {
> +		dev_err(data->dev, "failed to read humidity\n");
> +		return ret;
> +	}
> +
> +	value_humidity = be16_to_cpu(data->be16);
> +	if (value_humidity == BMP280_HUMIDITY_SKIPPED) {
> +		dev_err(data->dev, "reading humidity skipped\n");
> +		return -EIO;
> +	}
> +	*adc_humidity = value_humidity;
> +
> +	return 0;
> +}

...
> @@ -313,8 +335,29 @@ static u32 bme280_compensate_humidity(struct bmp280_data *data,
>   *
>   * Taken from datasheet, Section 3.11.3, "Compensation formula".
>   */
Is this comment still relevant here? Seems it should probably move to follow
that maths.

> -static s32 bmp280_compensate_temp(struct bmp280_data *data,
> -				  u32 adc_temp)
> +static int bmp280_read_temp_adc(struct bmp280_data *data, u32 *adc_temp)
> +{

>  
>  static int bmp380_read_press(struct bmp280_data *data, int *val, int *val2)
>  {
> -	u32 adc_press, comp_press;
> +	u32 adc_press, comp_press, t_fine;
>  	int ret;
>  
> -	/* Read and compensate for temperature so we get a reading of t_fine */
> -	ret = bmp380_read_temp(data, NULL, NULL);
> +	ret = bmp380_get_t_fine(data, &t_fine);
>  	if (ret)
>  		return ret;
>  
> -	ret = regmap_bulk_read(data->regmap, BMP380_REG_PRESS_XLSB,
> -			       data->buf, sizeof(data->buf));
> -	if (ret) {
> -		dev_err(data->dev, "failed to read pressure\n");
> +	ret = bmp380_read_press_adc(data, &adc_press);
> +	if (ret)
>  		return ret;
> -	}
>  
> -	adc_press = get_unaligned_le24(data->buf);
> -	if (adc_press == BMP380_PRESS_SKIPPED) {
> -		dev_err(data->dev, "reading pressure skipped\n");
> -		return -EIO;
> -	}
> -	comp_press = bmp380_compensate_press(data, adc_press);
> +	comp_press = bmp380_compensate_press(data, adc_press, t_fine);
>  
> +	/* IIO units are in kPa */

Probably worth keeping the reference to what the unit of the
datasheet maths is around.

>  	*val = comp_press;
> -	/* Compensated pressure is in cPa (centipascals) */
>  	*val2 = 100000;
>  
>  	return IIO_VAL_FRACTIONAL;
> @@ -1825,7 +1916,7 @@ static int bmp180_wait_for_eoc(struct bmp280_data *data, u8 ctrl_meas)
>  	return 0;
>  }


> -static u32 bmp180_compensate_press(struct bmp280_data *data, u32 adc_press)
> +static u32 bmp180_compensate_press(struct bmp280_data *data, u32 adc_press,
> +				   s32 t_fine)
>  {
>  	struct bmp180_calib *calib = &data->calib.bmp180;
>  	s32 oss = data->oversampling_press;
> @@ -1965,7 +2068,7 @@ static u32 bmp180_compensate_press(struct bmp280_data *data, u32 adc_press)
>  	s32 b3, b6;
>  	u32 b4, b7;
>  
> -	b6 = data->t_fine - 4000;
> +	b6 = t_fine - 4000;
>  	x1 = (calib->B2 * (b6 * b6 >> 12)) >> 11;
>  	x2 = calib->AC2 * b6 >> 11;
>  	x3 = x1 + x2;
> @@ -1974,7 +2077,7 @@ static u32 bmp180_compensate_press(struct bmp280_data *data, u32 adc_press)
>  	x2 = (calib->B1 * ((b6 * b6) >> 12)) >> 16;
>  	x3 = (x1 + x2 + 2) >> 2;
>  	b4 = calib->AC4 * (u32)(x3 + 32768) >> 15;
> -	b7 = (adc_press - b3) * (50000 >> oss);
> +	b7 = (((u32)adc_press) - b3) * (50000 >> oss);

Casting from u32 to u32?

>  	if (b7 < 0x80000000)
>  		p = (b7 * 2) / b4;
>  	else
> @@ -1990,19 +2093,19 @@ static u32 bmp180_compensate_press(struct bmp280_data *data, u32 adc_press)
>  static int bmp180_read_press(struct bmp280_data *data, int *val, int *val2)

> +	/* IIO units are in kPa */

I think this is an unrelated improvement as original code doesn't have such a comment.
So shouldn't really be in this patch. If you want to keep it here rather than pushing it
into an additional patch, mention it in the commit message. "additional comments on base
units added for consistency" or something like that.
>  	*val = comp_press;
>  	*val2 = 1000;

Re: [PATCH v6 5/9] iio: pressure: bmp280: Refactorize reading functions

[Vasileios Amoiridis]

On Sun, May 12, 2024 at 01:24:12PM +0100, Jonathan Cameron wrote:
> On Wed,  8 May 2024 18:52:03 +0200
> Vasileios Amoiridis <vassilisamir@gmail.com> wrote:
> 
> > For BMP18x, BMP28x, BME280, BMP38x the reading of the pressure
> > value requires an update of the t_fine variable which happens
> > through reading the temperature value.
> > 
> > So all the bmpxxx_read_press() functions of the above sensors
> > are internally calling the equivalent bmpxxx_read_temp() function
> > in order to update the t_fine value. By just looking at the code
> > this functionality is a bit hidden and is not easy to understand
> > why those channels are not independent.
> > 
> > This commit tries to clear these things a bit by splitting the
> > bmpxxx_{read/compensate}_{temp/press/humid}() to the following:
> > 
> > i. bmpxxx_read_{temp/press/humid}_adc(): read the raw value from
> > the sensor.
> > 
> > ii. bmpxx_calc_t_fine(): calculate the t_fine variable.
> > 
> > iii. bmpxxx_get_t_fine(): get the t_fine variable.
> > 
> > iv. bmpxxx_compensate_{temp/press/humid}(): compensate the adc
> > values and return the calculated value.
> > 
> > v. bmpxxx_read_{temp/press/humid}(): combine calls of the
> > aforementioned functions to return the requested value.
> > 
> > Suggested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> > Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
> A few minor things inline.  Given I've picked up the 1st 4 patches,
> please base your v7 on top of those.
> 
> Thanks,
> 
> Jonathan
> 
> > ---
> >  drivers/iio/pressure/bmp280-core.c | 361 ++++++++++++++++++-----------
> >  drivers/iio/pressure/bmp280.h      |   6 -
> >  2 files changed, 232 insertions(+), 135 deletions(-)
> > 
> > diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
> > index dd5c526dacbd..a864f8db8e24 100644
> > --- a/drivers/iio/pressure/bmp280-core.c
> > +++ b/drivers/iio/pressure/bmp280-core.c
> > @@ -288,13 +288,35 @@ static int bme280_read_calib(struct bmp280_data *data)
> >   *
> >   * Taken from BME280 datasheet, Section 4.2.3, "Compensation formula".
> >   */
> 
> Seems this comment should probably follow the maths which has moved.
> 
> > +static int bme280_read_humid_adc(struct bmp280_data *data, u16 *adc_humidity)
> > +{
> > +	u16 value_humidity;
> > +	int ret;
> > +
> > +	ret = regmap_bulk_read(data->regmap, BME280_REG_HUMIDITY_MSB,
> > +			       &data->be16, sizeof(data->be16));
> > +	if (ret) {
> > +		dev_err(data->dev, "failed to read humidity\n");
> > +		return ret;
> > +	}
> > +
> > +	value_humidity = be16_to_cpu(data->be16);
> > +	if (value_humidity == BMP280_HUMIDITY_SKIPPED) {
> > +		dev_err(data->dev, "reading humidity skipped\n");
> > +		return -EIO;
> > +	}
> > +	*adc_humidity = value_humidity;
> > +
> > +	return 0;
> > +}
> 
> ...
> > @@ -313,8 +335,29 @@ static u32 bme280_compensate_humidity(struct bmp280_data *data,
> >   *
> >   * Taken from datasheet, Section 3.11.3, "Compensation formula".
> >   */
> Is this comment still relevant here? Seems it should probably move to follow
> that maths.
> 
> > -static s32 bmp280_compensate_temp(struct bmp280_data *data,
> > -				  u32 adc_temp)
> > +static int bmp280_read_temp_adc(struct bmp280_data *data, u32 *adc_temp)
> > +{
> 
> >  
> >  static int bmp380_read_press(struct bmp280_data *data, int *val, int *val2)
> >  {
> > -	u32 adc_press, comp_press;
> > +	u32 adc_press, comp_press, t_fine;
> >  	int ret;
> >  
> > -	/* Read and compensate for temperature so we get a reading of t_fine */
> > -	ret = bmp380_read_temp(data, NULL, NULL);
> > +	ret = bmp380_get_t_fine(data, &t_fine);
> >  	if (ret)
> >  		return ret;
> >  
> > -	ret = regmap_bulk_read(data->regmap, BMP380_REG_PRESS_XLSB,
> > -			       data->buf, sizeof(data->buf));
> > -	if (ret) {
> > -		dev_err(data->dev, "failed to read pressure\n");
> > +	ret = bmp380_read_press_adc(data, &adc_press);
> > +	if (ret)
> >  		return ret;
> > -	}
> >  
> > -	adc_press = get_unaligned_le24(data->buf);
> > -	if (adc_press == BMP380_PRESS_SKIPPED) {
> > -		dev_err(data->dev, "reading pressure skipped\n");
> > -		return -EIO;
> > -	}
> > -	comp_press = bmp380_compensate_press(data, adc_press);
> > +	comp_press = bmp380_compensate_press(data, adc_press, t_fine);
> >  
> > +	/* IIO units are in kPa */
> 
> Probably worth keeping the reference to what the unit of the
> datasheet maths is around.
> 
> >  	*val = comp_press;
> > -	/* Compensated pressure is in cPa (centipascals) */
> >  	*val2 = 100000;
> >  
> >  	return IIO_VAL_FRACTIONAL;
> > @@ -1825,7 +1916,7 @@ static int bmp180_wait_for_eoc(struct bmp280_data *data, u8 ctrl_meas)
> >  	return 0;
> >  }
> 
> 
> > -static u32 bmp180_compensate_press(struct bmp280_data *data, u32 adc_press)
> > +static u32 bmp180_compensate_press(struct bmp280_data *data, u32 adc_press,
> > +				   s32 t_fine)
> >  {
> >  	struct bmp180_calib *calib = &data->calib.bmp180;
> >  	s32 oss = data->oversampling_press;
> > @@ -1965,7 +2068,7 @@ static u32 bmp180_compensate_press(struct bmp280_data *data, u32 adc_press)
> >  	s32 b3, b6;
> >  	u32 b4, b7;
> >  
> > -	b6 = data->t_fine - 4000;
> > +	b6 = t_fine - 4000;
> >  	x1 = (calib->B2 * (b6 * b6 >> 12)) >> 11;
> >  	x2 = calib->AC2 * b6 >> 11;
> >  	x3 = x1 + x2;
> > @@ -1974,7 +2077,7 @@ static u32 bmp180_compensate_press(struct bmp280_data *data, u32 adc_press)
> >  	x2 = (calib->B1 * ((b6 * b6) >> 12)) >> 16;
> >  	x3 = (x1 + x2 + 2) >> 2;
> >  	b4 = calib->AC4 * (u32)(x3 + 32768) >> 15;
> > -	b7 = (adc_press - b3) * (50000 >> oss);
> > +	b7 = (((u32)adc_press) - b3) * (50000 >> oss);
> 
> Casting from u32 to u32?
> 
> >  	if (b7 < 0x80000000)
> >  		p = (b7 * 2) / b4;
> >  	else
> > @@ -1990,19 +2093,19 @@ static u32 bmp180_compensate_press(struct bmp280_data *data, u32 adc_press)
> >  static int bmp180_read_press(struct bmp280_data *data, int *val, int *val2)
> 
> > +	/* IIO units are in kPa */
> 
> I think this is an unrelated improvement as original code doesn't have such a comment.
> So shouldn't really be in this patch. If you want to keep it here rather than pushing it
> into an additional patch, mention it in the commit message. "additional comments on base
> units added for consistency" or something like that.
> >  	*val = comp_press;
> >  	*val2 = 1000;

Hi Jonathan!

Thank you very much once again for the amazing feedback!

As it looks like, I changed the code but I forgot to move the
comments accordingly. Thank you very much for pointing this out.
The extra comments are indeed not necessary, they don't add some
specific value so I can drop them.

Cheers,
Vasilis

[PATCH v6 6/9] iio: pressure: bmp280: Introduce new cleanup routines

[Vasileios Amoiridis]

Introduce new linux/cleanup.h with the guard(mutex) functionality.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Suggested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
---
 drivers/iio/pressure/bmp280-core.c | 131 ++++++++++++-----------------
 1 file changed, 56 insertions(+), 75 deletions(-)

diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
index a864f8db8e24..eed356bcf8a2 100644
--- a/drivers/iio/pressure/bmp280-core.c
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -27,6 +27,7 @@
 
 #include <linux/bitops.h>
 #include <linux/bitfield.h>
+#include <linux/cleanup.h>
 #include <linux/completion.h>
 #include <linux/delay.h>
 #include <linux/device.h>
@@ -508,77 +509,67 @@ static int bme280_read_humid(struct bmp280_data *data, int *val, int *val2)
 	return IIO_VAL_INT;
 }
 
-static int bmp280_read_raw(struct iio_dev *indio_dev,
-			   struct iio_chan_spec const *chan,
-			   int *val, int *val2, long mask)
+static int bmp280_read_raw_impl(struct iio_dev *indio_dev,
+				struct iio_chan_spec const *chan,
+				int *val, int *val2, long mask)
 {
 	struct bmp280_data *data = iio_priv(indio_dev);
-	int ret;
 
-	pm_runtime_get_sync(data->dev);
-	mutex_lock(&data->lock);
+	guard(mutex)(&data->lock);
 
 	switch (mask) {
 	case IIO_CHAN_INFO_PROCESSED:
 		switch (chan->type) {
 		case IIO_HUMIDITYRELATIVE:
-			ret = data->chip_info->read_humid(data, val, val2);
-			break;
+			return data->chip_info->read_humid(data, val, val2);
 		case IIO_PRESSURE:
-			ret = data->chip_info->read_press(data, val, val2);
-			break;
+			return data->chip_info->read_press(data, val, val2);
 		case IIO_TEMP:
-			ret = data->chip_info->read_temp(data, val, val2);
-			break;
+			return data->chip_info->read_temp(data, val, val2);
 		default:
-			ret = -EINVAL;
-			break;
+			return -EINVAL;
 		}
-		break;
 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
 		switch (chan->type) {
 		case IIO_HUMIDITYRELATIVE:
 			*val = 1 << data->oversampling_humid;
-			ret = IIO_VAL_INT;
-			break;
+			return IIO_VAL_INT;
 		case IIO_PRESSURE:
 			*val = 1 << data->oversampling_press;
-			ret = IIO_VAL_INT;
-			break;
+			return IIO_VAL_INT;
 		case IIO_TEMP:
 			*val = 1 << data->oversampling_temp;
-			ret = IIO_VAL_INT;
-			break;
+			return IIO_VAL_INT;
 		default:
-			ret = -EINVAL;
-			break;
+			return -EINVAL;
 		}
-		break;
 	case IIO_CHAN_INFO_SAMP_FREQ:
-		if (!data->chip_info->sampling_freq_avail) {
-			ret = -EINVAL;
-			break;
-		}
+		if (!data->chip_info->sampling_freq_avail)
+			return -EINVAL;
 
 		*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;
+		return IIO_VAL_INT_PLUS_MICRO;
 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
-		if (!data->chip_info->iir_filter_coeffs_avail) {
-			ret = -EINVAL;
-			break;
-		}
+		if (!data->chip_info->iir_filter_coeffs_avail)
+			return -EINVAL;
 
 		*val = (1 << data->iir_filter_coeff) - 1;
-		ret = IIO_VAL_INT;
-		break;
+		return IIO_VAL_INT;
 	default:
-		ret = -EINVAL;
-		break;
+		return -EINVAL;
 	}
+}
+
+static int bmp280_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan,
+			   int *val, int *val2, long mask)
+{
+	struct bmp280_data *data = iio_priv(indio_dev);
+	int ret;
 
-	mutex_unlock(&data->lock);
+	pm_runtime_get_sync(data->dev);
+	ret = bmp280_read_raw_impl(indio_dev, chan, val, val2, mask);
 	pm_runtime_mark_last_busy(data->dev);
 	pm_runtime_put_autosuspend(data->dev);
 
@@ -710,12 +701,13 @@ static int bmp280_write_iir_filter_coeffs(struct bmp280_data *data, int val)
 	return -EINVAL;
 }
 
-static int bmp280_write_raw(struct iio_dev *indio_dev,
-			    struct iio_chan_spec const *chan,
-			    int val, int val2, long mask)
+static int bmp280_write_raw_impl(struct iio_dev *indio_dev,
+				 struct iio_chan_spec const *chan,
+				 int val, int val2, long mask)
 {
 	struct bmp280_data *data = iio_priv(indio_dev);
-	int ret = 0;
+
+	guard(mutex)(&data->lock);
 
 	/*
 	 * Helper functions to update sensor running configuration.
@@ -725,45 +717,36 @@ static int bmp280_write_raw(struct iio_dev *indio_dev,
 	 */
 	switch (mask) {
 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
-		pm_runtime_get_sync(data->dev);
-		mutex_lock(&data->lock);
 		switch (chan->type) {
 		case IIO_HUMIDITYRELATIVE:
-			ret = bme280_write_oversampling_ratio_humid(data, val);
-			break;
+			return bme280_write_oversampling_ratio_humid(data, val);
 		case IIO_PRESSURE:
-			ret = bmp280_write_oversampling_ratio_press(data, val);
-			break;
+			return bmp280_write_oversampling_ratio_press(data, val);
 		case IIO_TEMP:
-			ret = bmp280_write_oversampling_ratio_temp(data, val);
-			break;
+			return bmp280_write_oversampling_ratio_temp(data, val);
 		default:
-			ret = -EINVAL;
-			break;
+			return -EINVAL;
 		}
-		mutex_unlock(&data->lock);
-		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;
+		return bmp280_write_sampling_frequency(data, val, val2);
 	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;
+		return bmp280_write_iir_filter_coeffs(data, val);
 	default:
 		return -EINVAL;
 	}
+}
+
+static int bmp280_write_raw(struct iio_dev *indio_dev,
+			 struct iio_chan_spec const *chan,
+			 int val, int val2, long mask)
+{
+	struct bmp280_data *data = iio_priv(indio_dev);
+	int ret;
+
+	pm_runtime_get_sync(data->dev);
+	ret = bmp280_write_raw_impl(indio_dev, chan, val, val2, mask);
+	pm_runtime_mark_last_busy(data->dev);
+	pm_runtime_put_autosuspend(data->dev);
 
 	return ret;
 }
@@ -1564,7 +1547,7 @@ static int bmp580_nvmem_read(void *priv, unsigned int offset, void *val,
 	int ret, addr;
 
 	pm_runtime_get_sync(data->dev);
-	mutex_lock(&data->lock);
+	guard(mutex)(&data->lock);
 
 	/* Set sensor in standby mode */
 	ret = regmap_update_bits(data->regmap, BMP580_REG_ODR_CONFIG,
@@ -1606,7 +1589,6 @@ static int bmp580_nvmem_read(void *priv, unsigned int offset, void *val,
 exit:
 	/* Restore chip config */
 	data->chip_info->chip_config(data);
-	mutex_unlock(&data->lock);
 	pm_runtime_mark_last_busy(data->dev);
 	pm_runtime_put_autosuspend(data->dev);
 	return ret;
@@ -1620,7 +1602,7 @@ static int bmp580_nvmem_write(void *priv, unsigned int offset, void *val,
 	int ret, addr;
 
 	pm_runtime_get_sync(data->dev);
-	mutex_lock(&data->lock);
+	guard(mutex)(&data->lock);
 
 	/* Set sensor in standby mode */
 	ret = regmap_update_bits(data->regmap, BMP580_REG_ODR_CONFIG,
@@ -1671,7 +1653,6 @@ static int bmp580_nvmem_write(void *priv, unsigned int offset, void *val,
 exit:
 	/* Restore chip config */
 	data->chip_info->chip_config(data);
-	mutex_unlock(&data->lock);
 	pm_runtime_mark_last_busy(data->dev);
 	pm_runtime_put_autosuspend(data->dev);
 	return ret;
-- 
2.25.1

[PATCH v6 7/9] iio: pressure: bmp280: Generalize read_{temp,press,humid}() functions

[Vasileios Amoiridis]

Add the coefficients for the IIO standard units and the IIO value
inside the chip_info structure.

Move the calculations for the IIO unit compatibility from inside the
read_{temp,press,humid}() functions and move them to the general
read_raw() function.

In this way, all the data for the calculation of the value are
located in the chip_info structure of the respective sensor.

Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
---
 drivers/iio/pressure/bmp280-core.c | 171 ++++++++++++++++-------------
 drivers/iio/pressure/bmp280.h      |  13 ++-
 2 files changed, 104 insertions(+), 80 deletions(-)

diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
index eed356bcf8a2..70ce37370ac6 100644
--- a/drivers/iio/pressure/bmp280-core.c
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -445,10 +445,8 @@ static u32 bmp280_compensate_press(struct bmp280_data *data,
 	return (u32)p;
 }
 
-static int bmp280_read_temp(struct bmp280_data *data,
-			    int *val, int *val2)
+static int bmp280_read_temp(struct bmp280_data *data, s32 *comp_temp)
 {
-	s32 comp_temp;
 	u32 adc_temp;
 	int ret;
 
@@ -456,17 +454,15 @@ static int bmp280_read_temp(struct bmp280_data *data,
 	if (ret)
 		return ret;
 
-	comp_temp = bmp280_compensate_temp(data, adc_temp);
+	*comp_temp = bmp280_compensate_temp(data, adc_temp);
 
-	/* IIO units are in milli Celsius */
-	*val = comp_temp * 10;
-	return IIO_VAL_INT;
+	return 0;
 }
 
-static int bmp280_read_press(struct bmp280_data *data,
-			     int *val, int *val2)
+static int bmp280_read_press(struct bmp280_data *data, u32 *comp_press)
 {
-	u32 comp_press, adc_press, t_fine;
+	u32 adc_press;
+	s32 t_fine;
 	int ret;
 
 	ret = bmp280_get_t_fine(data, &t_fine);
@@ -477,18 +473,13 @@ static int bmp280_read_press(struct bmp280_data *data,
 	if (ret)
 		return ret;
 
-	comp_press = bmp280_compensate_press(data, adc_press, t_fine);
+	*comp_press = bmp280_compensate_press(data, adc_press, t_fine);
 
-	/* IIO units are in kPa */
-	*val = comp_press;
-	*val2 = 256000;
-
-	return IIO_VAL_FRACTIONAL;
+	return 0;
 }
 
-static int bme280_read_humid(struct bmp280_data *data, int *val, int *val2)
+static int bme280_read_humid(struct bmp280_data *data, u32 *comp_humidity)
 {
-	u32 comp_humidity;
 	u16 adc_humidity;
 	s32 t_fine;
 	int ret;
@@ -501,12 +492,9 @@ static int bme280_read_humid(struct bmp280_data *data, int *val, int *val2)
 	if (ret)
 		return ret;
 
-	comp_humidity = bme280_compensate_humidity(data, adc_humidity, t_fine);
+	*comp_humidity = bme280_compensate_humidity(data, adc_humidity, t_fine);
 
-	/* IIO units are in 1000 * % */
-	*val = comp_humidity * 1000 / 1024;
-
-	return IIO_VAL_INT;
+	return 0;
 }
 
 static int bmp280_read_raw_impl(struct iio_dev *indio_dev,
@@ -514,6 +502,8 @@ static int bmp280_read_raw_impl(struct iio_dev *indio_dev,
 				int *val, int *val2, long mask)
 {
 	struct bmp280_data *data = iio_priv(indio_dev);
+	int chan_value;
+	int ret;
 
 	guard(mutex)(&data->lock);
 
@@ -521,11 +511,29 @@ static int bmp280_read_raw_impl(struct iio_dev *indio_dev,
 	case IIO_CHAN_INFO_PROCESSED:
 		switch (chan->type) {
 		case IIO_HUMIDITYRELATIVE:
-			return data->chip_info->read_humid(data, val, val2);
+			ret = data->chip_info->read_humid(data, &chan_value);
+			if (ret)
+				return ret;
+
+			*val = data->chip_info->humid_coeffs[0] * chan_value;
+			*val2 = data->chip_info->humid_coeffs[1];
+			return data->chip_info->humid_coeffs_type;
 		case IIO_PRESSURE:
-			return data->chip_info->read_press(data, val, val2);
+			ret = data->chip_info->read_press(data, &chan_value);
+			if (ret)
+				return ret;
+
+			*val = data->chip_info->press_coeffs[0] * chan_value;
+			*val2 = data->chip_info->press_coeffs[1];
+			return data->chip_info->press_coeffs_type;
 		case IIO_TEMP:
-			return data->chip_info->read_temp(data, val, val2);
+			ret = data->chip_info->read_temp(data, &chan_value);
+			if (ret)
+				return ret;
+
+			*val = data->chip_info->temp_coeffs[0] * chan_value;
+			*val2 = data->chip_info->temp_coeffs[1];
+			return data->chip_info->temp_coeffs_type;
 		default:
 			return -EINVAL;
 		}
@@ -825,6 +833,8 @@ static int bmp280_chip_config(struct bmp280_data *data)
 
 static const int bmp280_oversampling_avail[] = { 1, 2, 4, 8, 16 };
 static const u8 bmp280_chip_ids[] = { BMP280_CHIP_ID };
+static const int bmp280_temp_coeffs[] = { 10, 1 };
+static const int bmp280_press_coeffs[] = { 1, 256000 };
 
 const struct bmp280_chip_info bmp280_chip_info = {
 	.id_reg = BMP280_REG_ID,
@@ -853,6 +863,11 @@ const struct bmp280_chip_info bmp280_chip_info = {
 	.num_oversampling_press_avail = ARRAY_SIZE(bmp280_oversampling_avail),
 	.oversampling_press_default = BMP280_OSRS_PRESS_16X - 1,
 
+	.temp_coeffs = bmp280_temp_coeffs,
+	.temp_coeffs_type = IIO_VAL_FRACTIONAL,
+	.press_coeffs = bmp280_press_coeffs,
+	.press_coeffs_type = IIO_VAL_FRACTIONAL,
+
 	.chip_config = bmp280_chip_config,
 	.read_temp = bmp280_read_temp,
 	.read_press = bmp280_read_press,
@@ -880,6 +895,7 @@ static int bme280_chip_config(struct bmp280_data *data)
 }
 
 static const u8 bme280_chip_ids[] = { BME280_CHIP_ID };
+static const int bme280_humid_coeffs[] = { 1000, 1024 };
 
 const struct bmp280_chip_info bme280_chip_info = {
 	.id_reg = BMP280_REG_ID,
@@ -902,6 +918,13 @@ const struct bmp280_chip_info bme280_chip_info = {
 	.num_oversampling_humid_avail = ARRAY_SIZE(bmp280_oversampling_avail),
 	.oversampling_humid_default = BME280_OSRS_HUMIDITY_16X - 1,
 
+	.temp_coeffs = bmp280_temp_coeffs,
+	.temp_coeffs_type = IIO_VAL_FRACTIONAL,
+	.press_coeffs = bmp280_press_coeffs,
+	.press_coeffs_type = IIO_VAL_FRACTIONAL,
+	.humid_coeffs = bme280_humid_coeffs,
+	.humid_coeffs_type = IIO_VAL_FRACTIONAL,
+
 	.chip_config = bme280_chip_config,
 	.read_temp = bmp280_read_temp,
 	.read_press = bmp280_read_press,
@@ -1094,9 +1117,8 @@ static u32 bmp380_compensate_press(struct bmp280_data *data,
 	return comp_press;
 }
 
-static int bmp380_read_temp(struct bmp280_data *data, int *val, int *val2)
+static int bmp380_read_temp(struct bmp280_data *data, s32 *comp_temp)
 {
-	s32 comp_temp;
 	u32 adc_temp;
 	int ret;
 
@@ -1104,16 +1126,14 @@ static int bmp380_read_temp(struct bmp280_data *data, int *val, int *val2)
 	if (ret)
 		return ret;
 
-	comp_temp = bmp380_compensate_temp(data, adc_temp);
+	*comp_temp = bmp380_compensate_temp(data, adc_temp);
 
-	/* IIO units are in milli Celsius */
-	*val = comp_temp * 10;
-	return IIO_VAL_INT;
+	return 0;
 }
 
-static int bmp380_read_press(struct bmp280_data *data, int *val, int *val2)
+static int bmp380_read_press(struct bmp280_data *data, u32 *comp_press)
 {
-	u32 adc_press, comp_press, t_fine;
+	u32 adc_press, t_fine;
 	int ret;
 
 	ret = bmp380_get_t_fine(data, &t_fine);
@@ -1124,13 +1144,9 @@ static int bmp380_read_press(struct bmp280_data *data, int *val, int *val2)
 	if (ret)
 		return ret;
 
-	comp_press = bmp380_compensate_press(data, adc_press, t_fine);
+	*comp_press = bmp380_compensate_press(data, adc_press, t_fine);
 
-	/* IIO units are in kPa */
-	*val = comp_press;
-	*val2 = 100000;
-
-	return IIO_VAL_FRACTIONAL;
+	return 0;
 }
 
 static int bmp380_read_calib(struct bmp280_data *data)
@@ -1301,6 +1317,8 @@ static int bmp380_chip_config(struct bmp280_data *data)
 static const int bmp380_oversampling_avail[] = { 1, 2, 4, 8, 16, 32 };
 static const int bmp380_iir_filter_coeffs_avail[] = { 1, 2, 4, 8, 16, 32, 64, 128};
 static const u8 bmp380_chip_ids[] = { BMP380_CHIP_ID, BMP390_CHIP_ID };
+static const int bmp380_temp_coeffs[] = { 10, 1 };
+static const int bmp380_press_coeffs[] = { 1, 100000 };
 
 const struct bmp280_chip_info bmp380_chip_info = {
 	.id_reg = BMP380_REG_ID,
@@ -1328,6 +1346,11 @@ const struct bmp280_chip_info bmp380_chip_info = {
 	.num_iir_filter_coeffs_avail = ARRAY_SIZE(bmp380_iir_filter_coeffs_avail),
 	.iir_filter_coeff_default = 2,
 
+	.temp_coeffs = bmp380_temp_coeffs,
+	.temp_coeffs_type = IIO_VAL_FRACTIONAL,
+	.press_coeffs = bmp380_press_coeffs,
+	.press_coeffs_type = IIO_VAL_FRACTIONAL,
+
 	.chip_config = bmp380_chip_config,
 	.read_temp = bmp380_read_temp,
 	.read_press = bmp380_read_press,
@@ -1448,9 +1471,8 @@ static int bmp580_nvm_operation(struct bmp280_data *data, bool is_write)
  * for what is expected on IIO ABI.
  */
 
-static int bmp580_read_temp(struct bmp280_data *data, int *val, int *val2)
+static int bmp580_read_temp(struct bmp280_data *data, s32 *raw_temp)
 {
-	s32 raw_temp;
 	int ret;
 
 	ret = regmap_bulk_read(data->regmap, BMP580_REG_TEMP_XLSB, data->buf,
@@ -1460,25 +1482,17 @@ static int bmp580_read_temp(struct bmp280_data *data, int *val, int *val2)
 		return ret;
 	}
 
-	raw_temp = get_unaligned_le24(data->buf);
-	if (raw_temp == BMP580_TEMP_SKIPPED) {
+	*raw_temp = get_unaligned_le24(data->buf);
+	if (*raw_temp == BMP580_TEMP_SKIPPED) {
 		dev_err(data->dev, "reading temperature skipped\n");
 		return -EIO;
 	}
 
-	/*
-	 * Temperature is returned in Celsius degrees in fractional
-	 * form down 2^16. We rescale by x1000 to return milli Celsius
-	 * to respect IIO ABI.
-	 */
-	*val = raw_temp * 1000;
-	*val2 = 16;
-	return IIO_VAL_FRACTIONAL_LOG2;
+	return 0;
 }
 
-static int bmp580_read_press(struct bmp280_data *data, int *val, int *val2)
+static int bmp580_read_press(struct bmp280_data *data, u32 *raw_press)
 {
-	u32 raw_press;
 	int ret;
 
 	ret = regmap_bulk_read(data->regmap, BMP580_REG_PRESS_XLSB, data->buf,
@@ -1488,18 +1502,13 @@ static int bmp580_read_press(struct bmp280_data *data, int *val, int *val2)
 		return ret;
 	}
 
-	raw_press = get_unaligned_le24(data->buf);
-	if (raw_press == BMP580_PRESS_SKIPPED) {
+	*raw_press = get_unaligned_le24(data->buf);
+	if (*raw_press == BMP580_PRESS_SKIPPED) {
 		dev_err(data->dev, "reading pressure skipped\n");
 		return -EIO;
 	}
-	/*
-	 * Pressure is returned in Pascals in fractional form down 2^16.
-	 * We rescale /1000 to convert to kilopascal to respect IIO ABI.
-	 */
-	*val = raw_press;
-	*val2 = 64000; /* 2^6 * 1000 */
-	return IIO_VAL_FRACTIONAL;
+
+	return 0;
 }
 
 static const int bmp580_odr_table[][2] = {
@@ -1813,6 +1822,8 @@ static int bmp580_chip_config(struct bmp280_data *data)
 
 static const int bmp580_oversampling_avail[] = { 1, 2, 4, 8, 16, 32, 64, 128 };
 static const u8 bmp580_chip_ids[] = { BMP580_CHIP_ID, BMP580_CHIP_ID_ALT };
+static const int bmp580_temp_coeffs[] = { 1000, 16 };
+static const int bmp580_press_coeffs[] = { 1, 64000};
 
 const struct bmp280_chip_info bmp580_chip_info = {
 	.id_reg = BMP580_REG_CHIP_ID,
@@ -1839,6 +1850,11 @@ const struct bmp280_chip_info bmp580_chip_info = {
 	.num_iir_filter_coeffs_avail = ARRAY_SIZE(bmp380_iir_filter_coeffs_avail),
 	.iir_filter_coeff_default = 2,
 
+	.temp_coeffs = bmp580_temp_coeffs,
+	.temp_coeffs_type = IIO_VAL_FRACTIONAL_LOG2,
+	.press_coeffs = bmp580_press_coeffs,
+	.press_coeffs_type = IIO_VAL_FRACTIONAL,
+
 	.chip_config = bmp580_chip_config,
 	.read_temp = bmp580_read_temp,
 	.read_press = bmp580_read_press,
@@ -1994,9 +2010,8 @@ static s32 bmp180_compensate_temp(struct bmp280_data *data, u32 adc_temp)
 	return (bmp180_calc_t_fine(data, adc_temp) + 8) / 16;
 }
 
-static int bmp180_read_temp(struct bmp280_data *data, int *val, int *val2)
+static int bmp180_read_temp(struct bmp280_data *data, s32 *comp_temp)
 {
-	s32 comp_temp;
 	u32 adc_temp;
 	int ret;
 
@@ -2004,11 +2019,9 @@ static int bmp180_read_temp(struct bmp280_data *data, int *val, int *val2)
 	if (ret)
 		return ret;
 
-	comp_temp = bmp180_compensate_temp(data, adc_temp);
+	*comp_temp = bmp180_compensate_temp(data, adc_temp);
 
-	/* IIO units are in milli Celsius */
-	*val = comp_temp * 100;
-	return IIO_VAL_INT;
+	return 0;
 }
 
 static int bmp180_read_press_adc(struct bmp280_data *data, u32 *adc_press)
@@ -2071,10 +2084,11 @@ static u32 bmp180_compensate_press(struct bmp280_data *data, u32 adc_press,
 	return p + ((x1 + x2 + 3791) >> 4);
 }
 
-static int bmp180_read_press(struct bmp280_data *data, int *val, int *val2)
+static int bmp180_read_press(struct bmp280_data *data, u32 *comp_press)
 {
-	u32 comp_press, adc_press;
+	u32 adc_press;
 	s32 t_fine;
+	int ret;
 
 	ret = bmp180_get_t_fine(data, &t_fine);
 	if (ret)
@@ -2084,13 +2098,9 @@ static int bmp180_read_press(struct bmp280_data *data, int *val, int *val2)
 	if (ret)
 		return ret;
 
-	comp_press = bmp180_compensate_press(data, adc_press, t_fine);
-
-	/* IIO units are in kPa */
-	*val = comp_press;
-	*val2 = 1000;
+	*comp_press = bmp180_compensate_press(data, adc_press, t_fine);
 
-	return IIO_VAL_FRACTIONAL;
+	return 0;
 }
 
 static int bmp180_chip_config(struct bmp280_data *data)
@@ -2101,6 +2111,8 @@ static int bmp180_chip_config(struct bmp280_data *data)
 static const int bmp180_oversampling_temp_avail[] = { 1 };
 static const int bmp180_oversampling_press_avail[] = { 1, 2, 4, 8 };
 static const u8 bmp180_chip_ids[] = { BMP180_CHIP_ID };
+static const int bmp180_temp_coeffs[] = { 100, 1 };
+static const int bmp180_press_coeffs[] = { 1, 1000 };
 
 const struct bmp280_chip_info bmp180_chip_info = {
 	.id_reg = BMP280_REG_ID,
@@ -2121,6 +2133,11 @@ const struct bmp280_chip_info bmp180_chip_info = {
 		ARRAY_SIZE(bmp180_oversampling_press_avail),
 	.oversampling_press_default = BMP180_MEAS_PRESS_8X,
 
+	.temp_coeffs = bmp180_temp_coeffs,
+	.temp_coeffs_type = IIO_VAL_FRACTIONAL,
+	.press_coeffs = bmp180_press_coeffs,
+	.press_coeffs_type = IIO_VAL_FRACTIONAL,
+
 	.chip_config = bmp180_chip_config,
 	.read_temp = bmp180_read_temp,
 	.read_press = bmp180_read_press,
diff --git a/drivers/iio/pressure/bmp280.h b/drivers/iio/pressure/bmp280.h
index 7c30e4d523be..a3d2cd722760 100644
--- a/drivers/iio/pressure/bmp280.h
+++ b/drivers/iio/pressure/bmp280.h
@@ -446,10 +446,17 @@ struct bmp280_chip_info {
 	int num_sampling_freq_avail;
 	int sampling_freq_default;
 
+	const int *temp_coeffs;
+	const int temp_coeffs_type;
+	const int *press_coeffs;
+	const int press_coeffs_type;
+	const int *humid_coeffs;
+	const int humid_coeffs_type;
+
 	int (*chip_config)(struct bmp280_data *data);
-	int (*read_temp)(struct bmp280_data *data, int *val, int *val2);
-	int (*read_press)(struct bmp280_data *data, int *val, int *val2);
-	int (*read_humid)(struct bmp280_data *data, int *val, int *val2);
+	int (*read_temp)(struct bmp280_data *data, s32 *adc_temp);
+	int (*read_press)(struct bmp280_data *data, u32 *adc_press);
+	int (*read_humid)(struct bmp280_data *data, u32 *adc_humidity);
 	int (*read_calib)(struct bmp280_data *data);
 	int (*preinit)(struct bmp280_data *data);
 };
-- 
2.25.1

[PATCH v6 8/9] iio: pressure: bmp280: Add SCALE, RAW values in channels and refactorize them

[Vasileios Amoiridis]

Add extra IIO_CHAN_INFO_SCALE and IIO_CHAN_INFO_RAW channels in order
to be able to calculate the processed value with standard userspace
IIO tools. Can be used for triggered buffers as well.

Even though it is not a good design choice to have SCALE, RAW and
PROCESSED together, the PROCESSED channel is kept for ABI compatibility.

While at it, separate BMPxxx and BMExxx device channels since BME
supports also humidity measurements.

Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
---
 drivers/iio/pressure/bmp280-core.c | 86 +++++++++++++++++++++++++++---
 1 file changed, 78 insertions(+), 8 deletions(-)

diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
index 70ce37370ac6..3f8144a0355b 100644
--- a/drivers/iio/pressure/bmp280-core.c
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -137,17 +137,45 @@ enum {
 static const struct iio_chan_spec bmp280_channels[] = {
 	{
 		.type = IIO_PRESSURE,
+		/* PROCESSED maintained for ABI backwards compatibility */
 		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
+				      BIT(IIO_CHAN_INFO_RAW) |
+				      BIT(IIO_CHAN_INFO_SCALE) |
 				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
 	},
 	{
 		.type = IIO_TEMP,
+		/* PROCESSED maintained for ABI backwards compatibility */
 		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
+				      BIT(IIO_CHAN_INFO_RAW) |
+				      BIT(IIO_CHAN_INFO_SCALE) |
+				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+	},
+};
+
+static const struct iio_chan_spec bme280_channels[] = {
+	{
+		.type = IIO_PRESSURE,
+		/* PROCESSED maintained for ABI backwards compatibility */
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
+				      BIT(IIO_CHAN_INFO_RAW) |
+				      BIT(IIO_CHAN_INFO_SCALE) |
+				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+	},
+	{
+		.type = IIO_TEMP,
+		/* PROCESSED maintained for ABI backwards compatibility */
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
+				      BIT(IIO_CHAN_INFO_RAW) |
+				      BIT(IIO_CHAN_INFO_SCALE) |
 				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
 	},
 	{
 		.type = IIO_HUMIDITYRELATIVE,
+		/* PROCESSED maintained for ABI backwards compatibility */
 		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
+				      BIT(IIO_CHAN_INFO_RAW) |
+				      BIT(IIO_CHAN_INFO_SCALE) |
 				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
 	},
 };
@@ -155,21 +183,20 @@ static const struct iio_chan_spec bmp280_channels[] = {
 static const struct iio_chan_spec bmp380_channels[] = {
 	{
 		.type = IIO_PRESSURE,
+		/* PROCESSED maintained for ABI backwards compatibility */
 		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
+				      BIT(IIO_CHAN_INFO_RAW) |
+				      BIT(IIO_CHAN_INFO_SCALE) |
 				      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,
+		/* PROCESSED maintained for ABI backwards compatibility */
 		.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_RAW) |
+				      BIT(IIO_CHAN_INFO_SCALE) |
 				      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),
@@ -537,6 +564,49 @@ static int bmp280_read_raw_impl(struct iio_dev *indio_dev,
 		default:
 			return -EINVAL;
 		}
+	case IIO_CHAN_INFO_RAW:
+		switch (chan->type) {
+		case IIO_HUMIDITYRELATIVE:
+			ret = data->chip_info->read_humid(data, &chan_value);
+			if (ret)
+				return ret;
+
+			*val = chan_value;
+			return IIO_VAL_INT;
+		case IIO_PRESSURE:
+			ret = data->chip_info->read_press(data, &chan_value);
+			if (ret)
+				return ret;
+
+			*val = chan_value;
+			return IIO_VAL_INT;
+		case IIO_TEMP:
+			ret = data->chip_info->read_temp(data, &chan_value);
+			if (ret)
+				return ret;
+
+			*val = chan_value;
+			return IIO_VAL_INT;
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->type) {
+		case IIO_HUMIDITYRELATIVE:
+			*val = data->chip_info->humid_coeffs[0];
+			*val2 = data->chip_info->humid_coeffs[1];
+			return data->chip_info->humid_coeffs_type;
+		case IIO_PRESSURE:
+			*val = data->chip_info->press_coeffs[0];
+			*val2 = data->chip_info->press_coeffs[1];
+			return data->chip_info->press_coeffs_type;
+		case IIO_TEMP:
+			*val = data->chip_info->temp_coeffs[0];
+			*val2 = data->chip_info->temp_coeffs[1];
+			return data->chip_info->temp_coeffs_type;
+		default:
+			return -EINVAL;
+		}
 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
 		switch (chan->type) {
 		case IIO_HUMIDITYRELATIVE:
@@ -903,7 +973,7 @@ const struct bmp280_chip_info bme280_chip_info = {
 	.num_chip_id = ARRAY_SIZE(bme280_chip_ids),
 	.regmap_config = &bmp280_regmap_config,
 	.start_up_time = 2000,
-	.channels = bmp280_channels,
+	.channels = bme280_channels,
 	.num_channels = 3,
 
 	.oversampling_temp_avail = bmp280_oversampling_avail,
-- 
2.25.1

Re: [PATCH v6 8/9] iio: pressure: bmp280: Add SCALE, RAW values in channels and refactorize them

[Jonathan Cameron]

On Wed,  8 May 2024 18:52:06 +0200
Vasileios Amoiridis <vassilisamir@gmail.com> wrote:

> Add extra IIO_CHAN_INFO_SCALE and IIO_CHAN_INFO_RAW channels in order
> to be able to calculate the processed value with standard userspace
> IIO tools. Can be used for triggered buffers as well.
> 
> Even though it is not a good design choice to have SCALE, RAW and
> PROCESSED together, the PROCESSED channel is kept for ABI compatibility.
> 
> While at it, separate BMPxxx and BMExxx device channels since BME
> supports also humidity measurements.
> 
> Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
num channels is now ARRAY_SIZE(xxx) for all of these rather than
the previous trick of using the same array and different numbers of channels.

As such I think you can just replace the 2, 3 with ARRAY_SIZE(bmp280_channels)
and ARRAY_SIZE(bme280_channels) which will give more obviously correct
and maintainable code.

Jonathan


> ---
>  drivers/iio/pressure/bmp280-core.c | 86 +++++++++++++++++++++++++++---
>  1 file changed, 78 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
> index 70ce37370ac6..3f8144a0355b 100644
> --- a/drivers/iio/pressure/bmp280-core.c
> +++ b/drivers/iio/pressure/bmp280-core.c
> @@ -137,17 +137,45 @@ enum {
>  static const struct iio_chan_spec bmp280_channels[] = {
>  	{
>  		.type = IIO_PRESSURE,
> +		/* PROCESSED maintained for ABI backwards compatibility */
>  		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
> +				      BIT(IIO_CHAN_INFO_RAW) |
> +				      BIT(IIO_CHAN_INFO_SCALE) |
>  				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
>  	},
>  	{
>  		.type = IIO_TEMP,
> +		/* PROCESSED maintained for ABI backwards compatibility */
>  		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
> +				      BIT(IIO_CHAN_INFO_RAW) |
> +				      BIT(IIO_CHAN_INFO_SCALE) |
> +				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
> +	},
> +};
> +
> +static const struct iio_chan_spec bme280_channels[] = {
> +	{
> +		.type = IIO_PRESSURE,
> +		/* PROCESSED maintained for ABI backwards compatibility */
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
> +				      BIT(IIO_CHAN_INFO_RAW) |
> +				      BIT(IIO_CHAN_INFO_SCALE) |
> +				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
> +	},
> +	{
> +		.type = IIO_TEMP,
> +		/* PROCESSED maintained for ABI backwards compatibility */
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
> +				      BIT(IIO_CHAN_INFO_RAW) |
> +				      BIT(IIO_CHAN_INFO_SCALE) |
>  				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
>  	},
>  	{
>  		.type = IIO_HUMIDITYRELATIVE,
> +		/* PROCESSED maintained for ABI backwards compatibility */
>  		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
> +				      BIT(IIO_CHAN_INFO_RAW) |
> +				      BIT(IIO_CHAN_INFO_SCALE) |
>  				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
>  	},
>  };
> @@ -155,21 +183,20 @@ static const struct iio_chan_spec bmp280_channels[] = {
>  static const struct iio_chan_spec bmp380_channels[] = {
>  	{
>  		.type = IIO_PRESSURE,
> +		/* PROCESSED maintained for ABI backwards compatibility */
>  		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
> +				      BIT(IIO_CHAN_INFO_RAW) |
> +				      BIT(IIO_CHAN_INFO_SCALE) |
>  				      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,
> +		/* PROCESSED maintained for ABI backwards compatibility */
>  		.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_RAW) |
> +				      BIT(IIO_CHAN_INFO_SCALE) |
>  				      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),
> @@ -537,6 +564,49 @@ static int bmp280_read_raw_impl(struct iio_dev *indio_dev,
>  		default:
>  			return -EINVAL;
>  		}
> +	case IIO_CHAN_INFO_RAW:
> +		switch (chan->type) {
> +		case IIO_HUMIDITYRELATIVE:
> +			ret = data->chip_info->read_humid(data, &chan_value);
> +			if (ret)
> +				return ret;
> +
> +			*val = chan_value;
> +			return IIO_VAL_INT;
> +		case IIO_PRESSURE:
> +			ret = data->chip_info->read_press(data, &chan_value);
> +			if (ret)
> +				return ret;
> +
> +			*val = chan_value;
> +			return IIO_VAL_INT;
> +		case IIO_TEMP:
> +			ret = data->chip_info->read_temp(data, &chan_value);
> +			if (ret)
> +				return ret;
> +
> +			*val = chan_value;
> +			return IIO_VAL_INT;
> +		default:
> +			return -EINVAL;
> +		}
> +	case IIO_CHAN_INFO_SCALE:
> +		switch (chan->type) {
> +		case IIO_HUMIDITYRELATIVE:
> +			*val = data->chip_info->humid_coeffs[0];
> +			*val2 = data->chip_info->humid_coeffs[1];
> +			return data->chip_info->humid_coeffs_type;
> +		case IIO_PRESSURE:
> +			*val = data->chip_info->press_coeffs[0];
> +			*val2 = data->chip_info->press_coeffs[1];
> +			return data->chip_info->press_coeffs_type;
> +		case IIO_TEMP:
> +			*val = data->chip_info->temp_coeffs[0];
> +			*val2 = data->chip_info->temp_coeffs[1];
> +			return data->chip_info->temp_coeffs_type;
> +		default:
> +			return -EINVAL;
> +		}
>  	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
>  		switch (chan->type) {
>  		case IIO_HUMIDITYRELATIVE:
> @@ -903,7 +973,7 @@ const struct bmp280_chip_info bme280_chip_info = {
>  	.num_chip_id = ARRAY_SIZE(bme280_chip_ids),
>  	.regmap_config = &bmp280_regmap_config,
>  	.start_up_time = 2000,
> -	.channels = bmp280_channels,
> +	.channels = bme280_channels,
>  	.num_channels = 3,
>  
>  	.oversampling_temp_avail = bmp280_oversampling_avail,

Re: [PATCH v6 8/9] iio: pressure: bmp280: Add SCALE, RAW values in channels and refactorize them

[Vasileios Amoiridis]

On Sun, May 12, 2024 at 01:29:14PM +0100, Jonathan Cameron wrote:
> On Wed,  8 May 2024 18:52:06 +0200
> Vasileios Amoiridis <vassilisamir@gmail.com> wrote:
> 
> > Add extra IIO_CHAN_INFO_SCALE and IIO_CHAN_INFO_RAW channels in order
> > to be able to calculate the processed value with standard userspace
> > IIO tools. Can be used for triggered buffers as well.
> > 
> > Even though it is not a good design choice to have SCALE, RAW and
> > PROCESSED together, the PROCESSED channel is kept for ABI compatibility.
> > 
> > While at it, separate BMPxxx and BMExxx device channels since BME
> > supports also humidity measurements.
> > 
> > Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
> num channels is now ARRAY_SIZE(xxx) for all of these rather than
> the previous trick of using the same array and different numbers of channels.
> 
> As such I think you can just replace the 2, 3 with ARRAY_SIZE(bmp280_channels)
> and ARRAY_SIZE(bme280_channels) which will give more obviously correct
> and maintainable code.
> 
> Jonathan
> 

Hi Jonathan!

Indeed, this is a very good addition!!!

Cheers,
Vasilis

> 
> > ---
> >  drivers/iio/pressure/bmp280-core.c | 86 +++++++++++++++++++++++++++---
> >  1 file changed, 78 insertions(+), 8 deletions(-)
> > 
> > diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
> > index 70ce37370ac6..3f8144a0355b 100644
> > --- a/drivers/iio/pressure/bmp280-core.c
> > +++ b/drivers/iio/pressure/bmp280-core.c
> > @@ -137,17 +137,45 @@ enum {
> >  static const struct iio_chan_spec bmp280_channels[] = {
> >  	{
> >  		.type = IIO_PRESSURE,
> > +		/* PROCESSED maintained for ABI backwards compatibility */
> >  		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
> > +				      BIT(IIO_CHAN_INFO_RAW) |
> > +				      BIT(IIO_CHAN_INFO_SCALE) |
> >  				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
> >  	},
> >  	{
> >  		.type = IIO_TEMP,
> > +		/* PROCESSED maintained for ABI backwards compatibility */
> >  		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
> > +				      BIT(IIO_CHAN_INFO_RAW) |
> > +				      BIT(IIO_CHAN_INFO_SCALE) |
> > +				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
> > +	},
> > +};
> > +
> > +static const struct iio_chan_spec bme280_channels[] = {
> > +	{
> > +		.type = IIO_PRESSURE,
> > +		/* PROCESSED maintained for ABI backwards compatibility */
> > +		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
> > +				      BIT(IIO_CHAN_INFO_RAW) |
> > +				      BIT(IIO_CHAN_INFO_SCALE) |
> > +				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
> > +	},
> > +	{
> > +		.type = IIO_TEMP,
> > +		/* PROCESSED maintained for ABI backwards compatibility */
> > +		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
> > +				      BIT(IIO_CHAN_INFO_RAW) |
> > +				      BIT(IIO_CHAN_INFO_SCALE) |
> >  				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
> >  	},
> >  	{
> >  		.type = IIO_HUMIDITYRELATIVE,
> > +		/* PROCESSED maintained for ABI backwards compatibility */
> >  		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
> > +				      BIT(IIO_CHAN_INFO_RAW) |
> > +				      BIT(IIO_CHAN_INFO_SCALE) |
> >  				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
> >  	},
> >  };
> > @@ -155,21 +183,20 @@ static const struct iio_chan_spec bmp280_channels[] = {
> >  static const struct iio_chan_spec bmp380_channels[] = {
> >  	{
> >  		.type = IIO_PRESSURE,
> > +		/* PROCESSED maintained for ABI backwards compatibility */
> >  		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
> > +				      BIT(IIO_CHAN_INFO_RAW) |
> > +				      BIT(IIO_CHAN_INFO_SCALE) |
> >  				      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,
> > +		/* PROCESSED maintained for ABI backwards compatibility */
> >  		.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_RAW) |
> > +				      BIT(IIO_CHAN_INFO_SCALE) |
> >  				      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),
> > @@ -537,6 +564,49 @@ static int bmp280_read_raw_impl(struct iio_dev *indio_dev,
> >  		default:
> >  			return -EINVAL;
> >  		}
> > +	case IIO_CHAN_INFO_RAW:
> > +		switch (chan->type) {
> > +		case IIO_HUMIDITYRELATIVE:
> > +			ret = data->chip_info->read_humid(data, &chan_value);
> > +			if (ret)
> > +				return ret;
> > +
> > +			*val = chan_value;
> > +			return IIO_VAL_INT;
> > +		case IIO_PRESSURE:
> > +			ret = data->chip_info->read_press(data, &chan_value);
> > +			if (ret)
> > +				return ret;
> > +
> > +			*val = chan_value;
> > +			return IIO_VAL_INT;
> > +		case IIO_TEMP:
> > +			ret = data->chip_info->read_temp(data, &chan_value);
> > +			if (ret)
> > +				return ret;
> > +
> > +			*val = chan_value;
> > +			return IIO_VAL_INT;
> > +		default:
> > +			return -EINVAL;
> > +		}
> > +	case IIO_CHAN_INFO_SCALE:
> > +		switch (chan->type) {
> > +		case IIO_HUMIDITYRELATIVE:
> > +			*val = data->chip_info->humid_coeffs[0];
> > +			*val2 = data->chip_info->humid_coeffs[1];
> > +			return data->chip_info->humid_coeffs_type;
> > +		case IIO_PRESSURE:
> > +			*val = data->chip_info->press_coeffs[0];
> > +			*val2 = data->chip_info->press_coeffs[1];
> > +			return data->chip_info->press_coeffs_type;
> > +		case IIO_TEMP:
> > +			*val = data->chip_info->temp_coeffs[0];
> > +			*val2 = data->chip_info->temp_coeffs[1];
> > +			return data->chip_info->temp_coeffs_type;
> > +		default:
> > +			return -EINVAL;
> > +		}
> >  	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
> >  		switch (chan->type) {
> >  		case IIO_HUMIDITYRELATIVE:
> > @@ -903,7 +973,7 @@ const struct bmp280_chip_info bme280_chip_info = {
> >  	.num_chip_id = ARRAY_SIZE(bme280_chip_ids),
> >  	.regmap_config = &bmp280_regmap_config,
> >  	.start_up_time = 2000,
> > -	.channels = bmp280_channels,
> > +	.channels = bme280_channels,
> >  	.num_channels = 3,
> >  
> >  	.oversampling_temp_avail = bmp280_oversampling_avail,
> 

[PATCH v6 9/9] iio: pressure: bmp280: Add triggered buffer support

[Vasileios Amoiridis]

BMP2xx, BME280, BMP3xx, and BMP5xx use continuous buffers for their
temperature, pressure and humidity readings. This facilitates the
use of burst/bulk reads in order to acquire data faster. The
approach is different from the one used in oneshot captures.

BMP085 & BMP1xx devices use a completely different measurement
process that is well defined and is used in their buffer_handler().

Suggested-by: Angel Iglesias <ang.iglesiasg@gmail.com>
Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>
---
 drivers/iio/pressure/Kconfig       |   2 +
 drivers/iio/pressure/bmp280-core.c | 339 +++++++++++++++++++++++++++--
 drivers/iio/pressure/bmp280-spi.c  |   8 +-
 drivers/iio/pressure/bmp280.h      |  21 +-
 4 files changed, 348 insertions(+), 22 deletions(-)

diff --git a/drivers/iio/pressure/Kconfig b/drivers/iio/pressure/Kconfig
index 3ad38506028e..0b5406a3f85d 100644
--- a/drivers/iio/pressure/Kconfig
+++ b/drivers/iio/pressure/Kconfig
@@ -31,6 +31,8 @@ config BMP280
 	select REGMAP
 	select BMP280_I2C if (I2C)
 	select BMP280_SPI if (SPI_MASTER)
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
 	help
 	  Say yes here to build support for Bosch Sensortec BMP180, BMP280, BMP380
 	  and BMP580 pressure and temperature sensors. Also supports the BME280 with
diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
index 3f8144a0355b..95f56836fd86 100644
--- a/drivers/iio/pressure/bmp280-core.c
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -41,7 +41,10 @@
 #include <linux/regmap.h>
 #include <linux/regulator/consumer.h>
 
+#include <linux/iio/buffer.h>
 #include <linux/iio/iio.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
 
 #include <asm/unaligned.h>
 
@@ -134,6 +137,12 @@ enum {
 	BMP380_P11 = 20,
 };
 
+enum bmp280_scan {
+	BMP280_PRESS,
+	BMP280_TEMP,
+	BME280_HUMID,
+};
+
 static const struct iio_chan_spec bmp280_channels[] = {
 	{
 		.type = IIO_PRESSURE,
@@ -142,6 +151,13 @@ static const struct iio_chan_spec bmp280_channels[] = {
 				      BIT(IIO_CHAN_INFO_RAW) |
 				      BIT(IIO_CHAN_INFO_SCALE) |
 				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+		.scan_index = 0,
+		.scan_type = {
+			.sign = 'u',
+			.realbits = 32,
+			.storagebits = 32,
+			.endianness = IIO_CPU,
+		},
 	},
 	{
 		.type = IIO_TEMP,
@@ -150,7 +166,15 @@ static const struct iio_chan_spec bmp280_channels[] = {
 				      BIT(IIO_CHAN_INFO_RAW) |
 				      BIT(IIO_CHAN_INFO_SCALE) |
 				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+		.scan_index = 1,
+		.scan_type = {
+			.sign = 's',
+			.realbits = 32,
+			.storagebits = 32,
+			.endianness = IIO_CPU,
+		},
 	},
+	IIO_CHAN_SOFT_TIMESTAMP(2),
 };
 
 static const struct iio_chan_spec bme280_channels[] = {
@@ -161,6 +185,13 @@ static const struct iio_chan_spec bme280_channels[] = {
 				      BIT(IIO_CHAN_INFO_RAW) |
 				      BIT(IIO_CHAN_INFO_SCALE) |
 				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+		.scan_index = 0,
+		.scan_type = {
+			.sign = 'u',
+			.realbits = 32,
+			.storagebits = 32,
+			.endianness = IIO_CPU,
+		},
 	},
 	{
 		.type = IIO_TEMP,
@@ -169,6 +200,13 @@ static const struct iio_chan_spec bme280_channels[] = {
 				      BIT(IIO_CHAN_INFO_RAW) |
 				      BIT(IIO_CHAN_INFO_SCALE) |
 				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+		.scan_index = 1,
+		.scan_type = {
+			.sign = 's',
+			.realbits = 32,
+			.storagebits = 32,
+			.endianness = IIO_CPU,
+		},
 	},
 	{
 		.type = IIO_HUMIDITYRELATIVE,
@@ -177,7 +215,15 @@ static const struct iio_chan_spec bme280_channels[] = {
 				      BIT(IIO_CHAN_INFO_RAW) |
 				      BIT(IIO_CHAN_INFO_SCALE) |
 				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+		.scan_index = 2,
+		.scan_type = {
+			.sign = 'u',
+			.realbits = 32,
+			.storagebits = 32,
+			.endianness = IIO_CPU,
+		},
 	},
+	IIO_CHAN_SOFT_TIMESTAMP(3),
 };
 
 static const struct iio_chan_spec bmp380_channels[] = {
@@ -190,6 +236,13 @@ static const struct iio_chan_spec bmp380_channels[] = {
 				      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),
+		.scan_index = 0,
+		.scan_type = {
+			.sign = 'u',
+			.realbits = 32,
+			.storagebits = 32,
+			.endianness = IIO_CPU,
+		},
 	},
 	{
 		.type = IIO_TEMP,
@@ -200,7 +253,15 @@ static const struct iio_chan_spec bmp380_channels[] = {
 				      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),
+		.scan_index = 1,
+		.scan_type = {
+			.sign = 's',
+			.realbits = 32,
+			.storagebits = 32,
+			.endianness = IIO_CPU,
+		},
 	},
+	IIO_CHAN_SOFT_TIMESTAMP(2),
 };
 
 static int bmp280_read_calib(struct bmp280_data *data)
@@ -322,7 +383,7 @@ static int bme280_read_humid_adc(struct bmp280_data *data, u16 *adc_humidity)
 	int ret;
 
 	ret = regmap_bulk_read(data->regmap, BME280_REG_HUMIDITY_MSB,
-			       &data->be16, sizeof(data->be16));
+			       &data->be16, BME280_NUM_HUMIDITY_BYTES);
 	if (ret) {
 		dev_err(data->dev, "failed to read humidity\n");
 		return ret;
@@ -369,7 +430,7 @@ static int bmp280_read_temp_adc(struct bmp280_data *data, u32 *adc_temp)
 	int ret;
 
 	ret = regmap_bulk_read(data->regmap, BMP280_REG_TEMP_MSB,
-			       data->buf, sizeof(data->buf));
+			       data->buf, BMP280_NUM_TEMP_BYTES);
 	if (ret) {
 		dev_err(data->dev, "failed to read temperature\n");
 		return ret;
@@ -430,7 +491,7 @@ static int bmp280_read_press_adc(struct bmp280_data *data, u32 *adc_press)
 	int ret;
 
 	ret = regmap_bulk_read(data->regmap, BMP280_REG_PRESS_MSB,
-			       data->buf, sizeof(data->buf));
+			       data->buf, BMP280_NUM_PRESS_BYTES);
 	if (ret) {
 		dev_err(data->dev, "failed to read pressure\n");
 		return ret;
@@ -874,6 +935,16 @@ static const struct iio_info bmp280_info = {
 	.write_raw = &bmp280_write_raw,
 };
 
+static const unsigned long bmp280_avail_scan_masks[] = {
+	BIT(BMP280_TEMP) | BIT(BMP280_PRESS),
+	0
+};
+
+static const unsigned long bme280_avail_scan_masks[] = {
+	BIT(BME280_HUMID) | BIT(BMP280_TEMP) | BIT(BMP280_PRESS),
+	0
+};
+
 static int bmp280_chip_config(struct bmp280_data *data)
 {
 	u8 osrs = FIELD_PREP(BMP280_OSRS_TEMP_MASK, data->oversampling_temp + 1) |
@@ -901,6 +972,74 @@ static int bmp280_chip_config(struct bmp280_data *data)
 	return ret;
 }
 
+static irqreturn_t bmp280_buffer_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct bmp280_data *data = iio_priv(indio_dev);
+	s32 adc_temp, adc_press, adc_humidity, t_fine;
+	u8 sizeof_burst_read;
+	int ret;
+
+	guard(mutex)(&data->lock);
+
+	/*
+	 * If humidity channel is enabled it means that we are called for the
+	 * BME280 humidity sensor.
+	 */
+	if (test_bit(BME280_HUMID, indio_dev->active_scan_mask))
+		sizeof_burst_read = BME280_BURST_READ_BYTES;
+	else
+		sizeof_burst_read = BMP280_BURST_READ_BYTES;
+
+	/* Burst read data registers */
+	ret = regmap_bulk_read(data->regmap, BMP280_REG_PRESS_MSB,
+			       data->buf, sizeof_burst_read);
+	if (ret) {
+		dev_err(data->dev, "failed to burst read sensor data\n");
+		goto out;
+	}
+
+	/* Temperature calculations */
+	adc_temp = FIELD_GET(BMP280_MEAS_TRIM_MASK, get_unaligned_be24(&data->buf[3]));
+	if (adc_temp == BMP280_TEMP_SKIPPED) {
+		dev_err(data->dev, "reading temperature skipped\n");
+		goto out;
+	}
+
+	data->sensor_data[1] = bmp280_compensate_temp(data, adc_temp);
+
+	/* Pressure calculations */
+	adc_press = FIELD_GET(BMP280_MEAS_TRIM_MASK, get_unaligned_be24(&data->buf[0]));
+	if (adc_press == BMP280_PRESS_SKIPPED) {
+		dev_err(data->dev, "reading pressure skipped\n");
+		goto out;
+	}
+
+	t_fine = bmp280_calc_t_fine(data, adc_temp);
+
+	data->sensor_data[0] = bmp280_compensate_press(data, adc_press, t_fine);
+
+	/* Humidity calculations */
+	if (test_bit(BME280_HUMID, indio_dev->active_scan_mask)) {
+		adc_humidity = get_unaligned_be16(&data->buf[6]);
+
+		if (adc_humidity == BMP280_HUMIDITY_SKIPPED) {
+			dev_err(data->dev, "reading humidity skipped\n");
+			goto out;
+		}
+		data->sensor_data[2] = bme280_compensate_humidity(data, adc_humidity, t_fine);
+	}
+
+	iio_push_to_buffers_with_timestamp(indio_dev, &data->sensor_data,
+					   iio_get_time_ns(indio_dev));
+
+out:
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
 static const int bmp280_oversampling_avail[] = { 1, 2, 4, 8, 16 };
 static const u8 bmp280_chip_ids[] = { BMP280_CHIP_ID };
 static const int bmp280_temp_coeffs[] = { 10, 1 };
@@ -913,7 +1052,8 @@ const struct bmp280_chip_info bmp280_chip_info = {
 	.regmap_config = &bmp280_regmap_config,
 	.start_up_time = 2000,
 	.channels = bmp280_channels,
-	.num_channels = 2,
+	.num_channels = 3,
+	.avail_scan_masks = bmp280_avail_scan_masks,
 
 	.oversampling_temp_avail = bmp280_oversampling_avail,
 	.num_oversampling_temp_avail = ARRAY_SIZE(bmp280_oversampling_avail),
@@ -942,6 +1082,8 @@ const struct bmp280_chip_info bmp280_chip_info = {
 	.read_temp = bmp280_read_temp,
 	.read_press = bmp280_read_press,
 	.read_calib = bmp280_read_calib,
+
+	.buffer_handler = bmp280_buffer_handler,
 };
 EXPORT_SYMBOL_NS(bmp280_chip_info, IIO_BMP280);
 
@@ -974,7 +1116,8 @@ const struct bmp280_chip_info bme280_chip_info = {
 	.regmap_config = &bmp280_regmap_config,
 	.start_up_time = 2000,
 	.channels = bme280_channels,
-	.num_channels = 3,
+	.num_channels = 4,
+	.avail_scan_masks = bme280_avail_scan_masks,
 
 	.oversampling_temp_avail = bmp280_oversampling_avail,
 	.num_oversampling_temp_avail = ARRAY_SIZE(bmp280_oversampling_avail),
@@ -1000,6 +1143,8 @@ const struct bmp280_chip_info bme280_chip_info = {
 	.read_press = bmp280_read_press,
 	.read_humid = bme280_read_humid,
 	.read_calib = bme280_read_calib,
+
+	.buffer_handler = bmp280_buffer_handler,
 };
 EXPORT_SYMBOL_NS(bme280_chip_info, IIO_BMP280);
 
@@ -1061,7 +1206,7 @@ static int bmp380_read_temp_adc(struct bmp280_data *data, u32 *adc_temp)
 	int ret;
 
 	ret = regmap_bulk_read(data->regmap, BMP380_REG_TEMP_XLSB,
-			       data->buf, sizeof(data->buf));
+			       data->buf, BMP280_NUM_TEMP_BYTES);
 	if (ret) {
 		dev_err(data->dev, "failed to read temperature\n");
 		return ret;
@@ -1130,7 +1275,7 @@ static int bmp380_read_press_adc(struct bmp280_data *data, u32 *adc_press)
 	int ret;
 
 	ret = regmap_bulk_read(data->regmap, BMP380_REG_PRESS_XLSB,
-			       data->buf, sizeof(data->buf));
+			       data->buf, BMP280_NUM_PRESS_BYTES);
 	if (ret) {
 		dev_err(data->dev, "failed to read pressure\n");
 		return ret;
@@ -1384,6 +1529,53 @@ static int bmp380_chip_config(struct bmp280_data *data)
 	return 0;
 }
 
+static irqreturn_t bmp380_buffer_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct bmp280_data *data = iio_priv(indio_dev);
+	s32 adc_temp, adc_press, t_fine;
+	int ret;
+
+	guard(mutex)(&data->lock);
+
+	/* Burst read data registers */
+	ret = regmap_bulk_read(data->regmap, BMP380_REG_PRESS_XLSB,
+			       data->buf, BMP280_BURST_READ_BYTES);
+	if (ret) {
+		dev_err(data->dev, "failed to burst read sensor data\n");
+		goto out;
+	}
+
+	/* Temperature calculations */
+	adc_temp = get_unaligned_le24(&data->buf[3]);
+	if (adc_temp == BMP380_TEMP_SKIPPED) {
+		dev_err(data->dev, "reading temperature skipped\n");
+		goto out;
+	}
+
+	data->sensor_data[1] = bmp380_compensate_temp(data, adc_temp);
+
+	/* Pressure calculations */
+	adc_press = get_unaligned_le24(&data->buf[0]);
+	if (adc_press == BMP380_PRESS_SKIPPED) {
+		dev_err(data->dev, "reading pressure skipped\n");
+		goto out;
+	}
+
+	t_fine = bmp380_calc_t_fine(data, adc_temp);
+
+	data->sensor_data[0] = bmp380_compensate_press(data, adc_press, t_fine);
+
+	iio_push_to_buffers_with_timestamp(indio_dev, &data->sensor_data,
+					   iio_get_time_ns(indio_dev));
+
+out:
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
 static const int bmp380_oversampling_avail[] = { 1, 2, 4, 8, 16, 32 };
 static const int bmp380_iir_filter_coeffs_avail[] = { 1, 2, 4, 8, 16, 32, 64, 128};
 static const u8 bmp380_chip_ids[] = { BMP380_CHIP_ID, BMP390_CHIP_ID };
@@ -1398,7 +1590,8 @@ const struct bmp280_chip_info bmp380_chip_info = {
 	.spi_read_extra_byte = true,
 	.start_up_time = 2000,
 	.channels = bmp380_channels,
-	.num_channels = 2,
+	.num_channels = 3,
+	.avail_scan_masks = bmp280_avail_scan_masks,
 
 	.oversampling_temp_avail = bmp380_oversampling_avail,
 	.num_oversampling_temp_avail = ARRAY_SIZE(bmp380_oversampling_avail),
@@ -1426,6 +1619,8 @@ const struct bmp280_chip_info bmp380_chip_info = {
 	.read_press = bmp380_read_press,
 	.read_calib = bmp380_read_calib,
 	.preinit = bmp380_preinit,
+
+	.buffer_handler = bmp380_buffer_handler,
 };
 EXPORT_SYMBOL_NS(bmp380_chip_info, IIO_BMP280);
 
@@ -1545,8 +1740,8 @@ static int bmp580_read_temp(struct bmp280_data *data, s32 *raw_temp)
 {
 	int ret;
 
-	ret = regmap_bulk_read(data->regmap, BMP580_REG_TEMP_XLSB, data->buf,
-			       sizeof(data->buf));
+	ret = regmap_bulk_read(data->regmap, BMP580_REG_TEMP_XLSB,
+			       data->buf, BMP280_NUM_TEMP_BYTES);
 	if (ret) {
 		dev_err(data->dev, "failed to read temperature\n");
 		return ret;
@@ -1565,8 +1760,8 @@ static int bmp580_read_press(struct bmp280_data *data, u32 *raw_press)
 {
 	int ret;
 
-	ret = regmap_bulk_read(data->regmap, BMP580_REG_PRESS_XLSB, data->buf,
-			       sizeof(data->buf));
+	ret = regmap_bulk_read(data->regmap, BMP580_REG_PRESS_XLSB,
+			       data->buf, BMP280_NUM_PRESS_BYTES);
 	if (ret) {
 		dev_err(data->dev, "failed to read pressure\n");
 		return ret;
@@ -1890,6 +2085,51 @@ static int bmp580_chip_config(struct bmp280_data *data)
 	return 0;
 }
 
+static irqreturn_t bmp580_buffer_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct bmp280_data *data = iio_priv(indio_dev);
+	s32 adc_temp, adc_press;
+	int ret;
+
+	guard(mutex)(&data->lock);
+
+	/* Burst read data registers */
+	ret = regmap_bulk_read(data->regmap, BMP580_REG_TEMP_XLSB,
+			       data->buf, BMP280_BURST_READ_BYTES);
+	if (ret) {
+		dev_err(data->dev, "failed to burst read sensor data\n");
+		goto out;
+	}
+
+	/* Temperature calculations */
+	adc_temp = get_unaligned_le24(&data->buf[0]);
+	if (adc_temp == BMP580_TEMP_SKIPPED) {
+		dev_err(data->dev, "reading temperature skipped\n");
+		goto out;
+	}
+
+	data->sensor_data[1] = adc_temp;
+
+	/* Pressure calculations */
+	adc_press = get_unaligned_le24(&data->buf[3]);
+	if (adc_press == BMP380_PRESS_SKIPPED) {
+		dev_err(data->dev, "reading pressure skipped\n");
+		goto out;
+	}
+
+	data->sensor_data[0] = adc_press;
+
+	iio_push_to_buffers_with_timestamp(indio_dev, &data->sensor_data,
+					   iio_get_time_ns(indio_dev));
+
+out:
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
 static const int bmp580_oversampling_avail[] = { 1, 2, 4, 8, 16, 32, 64, 128 };
 static const u8 bmp580_chip_ids[] = { BMP580_CHIP_ID, BMP580_CHIP_ID_ALT };
 static const int bmp580_temp_coeffs[] = { 1000, 16 };
@@ -1902,7 +2142,8 @@ const struct bmp280_chip_info bmp580_chip_info = {
 	.regmap_config = &bmp580_regmap_config,
 	.start_up_time = 2000,
 	.channels = bmp380_channels,
-	.num_channels = 2,
+	.num_channels = 3,
+	.avail_scan_masks = bmp280_avail_scan_masks,
 
 	.oversampling_temp_avail = bmp580_oversampling_avail,
 	.num_oversampling_temp_avail = ARRAY_SIZE(bmp580_oversampling_avail),
@@ -1929,6 +2170,8 @@ const struct bmp280_chip_info bmp580_chip_info = {
 	.read_temp = bmp580_read_temp,
 	.read_press = bmp580_read_press,
 	.preinit = bmp580_preinit,
+
+	.buffer_handler = bmp580_buffer_handler,
 };
 EXPORT_SYMBOL_NS(bmp580_chip_info, IIO_BMP280);
 
@@ -2107,7 +2350,7 @@ static int bmp180_read_press_adc(struct bmp280_data *data, u32 *adc_press)
 		return ret;
 
 	ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB,
-			       data->buf, sizeof(data->buf));
+			       data->buf, BMP280_NUM_PRESS_BYTES);
 	if (ret) {
 		dev_err(data->dev, "failed to read pressure\n");
 		return ret;
@@ -2178,6 +2421,36 @@ static int bmp180_chip_config(struct bmp280_data *data)
 	return 0;
 }
 
+static irqreturn_t bmp180_buffer_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct bmp280_data *data = iio_priv(indio_dev);
+	int ret, chan_value;
+
+	guard(mutex)(&data->lock);
+
+	ret = bmp180_read_temp(data, &chan_value);
+	if (ret)
+		goto out;
+
+	data->sensor_data[1] = chan_value;
+
+	ret = bmp180_read_press(data, &chan_value);
+	if (ret)
+		goto out;
+
+	data->sensor_data[0] = chan_value;
+
+	iio_push_to_buffers_with_timestamp(indio_dev, &data->sensor_data,
+					   iio_get_time_ns(indio_dev));
+
+out:
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
 static const int bmp180_oversampling_temp_avail[] = { 1 };
 static const int bmp180_oversampling_press_avail[] = { 1, 2, 4, 8 };
 static const u8 bmp180_chip_ids[] = { BMP180_CHIP_ID };
@@ -2191,7 +2464,8 @@ const struct bmp280_chip_info bmp180_chip_info = {
 	.regmap_config = &bmp180_regmap_config,
 	.start_up_time = 2000,
 	.channels = bmp280_channels,
-	.num_channels = 2,
+	.num_channels = 3,
+	.avail_scan_masks = bmp280_avail_scan_masks,
 
 	.oversampling_temp_avail = bmp180_oversampling_temp_avail,
 	.num_oversampling_temp_avail =
@@ -2212,6 +2486,8 @@ const struct bmp280_chip_info bmp180_chip_info = {
 	.read_temp = bmp180_read_temp,
 	.read_press = bmp180_read_press,
 	.read_calib = bmp180_read_calib,
+
+	.buffer_handler = bmp180_buffer_handler,
 };
 EXPORT_SYMBOL_NS(bmp180_chip_info, IIO_BMP280);
 
@@ -2257,6 +2533,30 @@ static int bmp085_fetch_eoc_irq(struct device *dev,
 	return 0;
 }
 
+static int bmp280_buffer_preenable(struct iio_dev *indio_dev)
+{
+	struct bmp280_data *data = iio_priv(indio_dev);
+
+	pm_runtime_get_sync(data->dev);
+
+	return 0;
+}
+
+static int bmp280_buffer_postdisable(struct iio_dev *indio_dev)
+{
+	struct bmp280_data *data = iio_priv(indio_dev);
+
+	pm_runtime_mark_last_busy(data->dev);
+	pm_runtime_put_autosuspend(data->dev);
+
+	return 0;
+}
+
+const struct iio_buffer_setup_ops bmp280_buffer_setup_ops = {
+	.preenable = bmp280_buffer_preenable,
+	.postdisable = bmp280_buffer_postdisable,
+};
+
 static void bmp280_pm_disable(void *data)
 {
 	struct device *dev = data;
@@ -2303,6 +2603,7 @@ int bmp280_common_probe(struct device *dev,
 	/* Apply initial values from chip info structure */
 	indio_dev->channels = chip_info->channels;
 	indio_dev->num_channels = chip_info->num_channels;
+	indio_dev->available_scan_masks = chip_info->avail_scan_masks;
 	data->oversampling_press = chip_info->oversampling_press_default;
 	data->oversampling_humid = chip_info->oversampling_humid_default;
 	data->oversampling_temp = chip_info->oversampling_temp_default;
@@ -2388,6 +2689,14 @@ int bmp280_common_probe(struct device *dev,
 					     "failed to read calibration coefficients\n");
 	}
 
+	ret = devm_iio_triggered_buffer_setup(data->dev, indio_dev,
+					      iio_pollfunc_store_time,
+					      data->chip_info->buffer_handler,
+					      NULL);
+	if (ret)
+		return dev_err_probe(data->dev, ret,
+				     "iio triggered buffer setup failed\n");
+
 	/*
 	 * Attempt to grab an optional EOC IRQ - only the BMP085 has this
 	 * however as it happens, the BMP085 shares the chip ID of BMP180
diff --git a/drivers/iio/pressure/bmp280-spi.c b/drivers/iio/pressure/bmp280-spi.c
index 62b4e58104cf..e5abee15950e 100644
--- a/drivers/iio/pressure/bmp280-spi.c
+++ b/drivers/iio/pressure/bmp280-spi.c
@@ -40,14 +40,10 @@ static int bmp380_regmap_spi_read(void *context, const void *reg,
 				  size_t reg_size, void *val, size_t val_size)
 {
 	struct spi_device *spi = to_spi_device(context);
-	u8 rx_buf[4];
+	u8 rx_buf[BME280_BURST_READ_BYTES + 1];
 	ssize_t status;
 
-	/*
-	 * Maximum number of consecutive bytes read for a temperature or
-	 * pressure measurement is 3.
-	 */
-	if (val_size > 3)
+	if (val_size > BME280_BURST_READ_BYTES)
 		return -EINVAL;
 
 	/*
diff --git a/drivers/iio/pressure/bmp280.h b/drivers/iio/pressure/bmp280.h
index a3d2cd722760..756c644354c2 100644
--- a/drivers/iio/pressure/bmp280.h
+++ b/drivers/iio/pressure/bmp280.h
@@ -304,6 +304,16 @@
 #define BMP280_PRESS_SKIPPED		0x80000
 #define BMP280_HUMIDITY_SKIPPED		0x8000
 
+/* Number of bytes for each value */
+#define BMP280_NUM_PRESS_BYTES		3
+#define BMP280_NUM_TEMP_BYTES		3
+#define BME280_NUM_HUMIDITY_BYTES	2
+#define BMP280_BURST_READ_BYTES		(BMP280_NUM_PRESS_BYTES + \
+					 BMP280_NUM_TEMP_BYTES)
+#define BME280_BURST_READ_BYTES		(BMP280_NUM_PRESS_BYTES + \
+					 BMP280_NUM_TEMP_BYTES + \
+					 BME280_NUM_HUMIDITY_BYTES)
+
 /* Core exported structs */
 
 static const char *const bmp280_supply_names[] = {
@@ -397,13 +407,19 @@ struct bmp280_data {
 	 */
 	int sampling_freq;
 
+	/*
+	 * Data to push to userspace triggered buffer. Up to 3 channels and
+	 * s64 timestamp, aligned.
+	 */
+	s32 sensor_data[6] __aligned(8);
+
 	/*
 	 * DMA (thus cache coherency maintenance) may require the
 	 * transfer buffers to live in their own cache lines.
 	 */
 	union {
 		/* Sensor data buffer */
-		u8 buf[3];
+		u8 buf[BME280_BURST_READ_BYTES];
 		/* Calibration data buffers */
 		__le16 bmp280_cal_buf[BMP280_CONTIGUOUS_CALIB_REGS / 2];
 		__be16 bmp180_cal_buf[BMP180_REG_CALIB_COUNT / 2];
@@ -425,6 +441,7 @@ struct bmp280_chip_info {
 	const struct iio_chan_spec *channels;
 	int num_channels;
 	unsigned int start_up_time;
+	const unsigned long *avail_scan_masks;
 
 	const int *oversampling_temp_avail;
 	int num_oversampling_temp_avail;
@@ -459,6 +476,8 @@ struct bmp280_chip_info {
 	int (*read_humid)(struct bmp280_data *data, u32 *adc_humidity);
 	int (*read_calib)(struct bmp280_data *data);
 	int (*preinit)(struct bmp280_data *data);
+
+	irqreturn_t (*buffer_handler)(int irq, void *p);
 };
 
 /* Chip infos for each variant */
-- 
2.25.1

Re: [PATCH v6 9/9] iio: pressure: bmp280: Add triggered buffer support

[Jonathan Cameron]

On Wed,  8 May 2024 18:52:07 +0200
Vasileios Amoiridis <vassilisamir@gmail.com> wrote:

> BMP2xx, BME280, BMP3xx, and BMP5xx use continuous buffers for their
> temperature, pressure and humidity readings. This facilitates the
> use of burst/bulk reads in order to acquire data faster. The
> approach is different from the one used in oneshot captures.
> 
> BMP085 & BMP1xx devices use a completely different measurement
> process that is well defined and is used in their buffer_handler().
> 
> Suggested-by: Angel Iglesias <ang.iglesiasg@gmail.com>
> Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com>

The switch to ARRAY_SIZE() for num channels will simplify this
because all those values will not need to be manually updated to
include the timestamp channel.

Other than that, this patch and earlier ones I didn't comment on (6, 7)
look good to me.

Thanks,

Jonathan

> diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
> index 3f8144a0355b..95f56836fd86 100644
> --- a/drivers/iio/pressure/bmp280-core.c
> +++ b/drivers/iio/pressure/bmp280-core.c

>  static const int bmp180_oversampling_temp_avail[] = { 1 };
>  static const int bmp180_oversampling_press_avail[] = { 1, 2, 4, 8 };
>  static const u8 bmp180_chip_ids[] = { BMP180_CHIP_ID };
> @@ -2191,7 +2464,8 @@ const struct bmp280_chip_info bmp180_chip_info = {
>  	.regmap_config = &bmp180_regmap_config,
>  	.start_up_time = 2000,
>  	.channels = bmp280_channels,
> -	.num_channels = 2,
> +	.num_channels = 3,

As comment on above, if this was ARRAY_SIZE(bmp280_channels) you wouldn't need
to update it here.  Probably best to make that change as part of the previous
patch.

> +	.avail_scan_masks = bmp280_avail_scan_masks,