[PATCH v3 0/2] iio: pressure: bmp280: add support for BMP180 and oversampling rate control

[PATCH v3 0/2] iio: pressure: bmp280: add support for BMP180 and oversampling rate control

[Akinobu Mita]

This series includes two patches: one that adds support for the BMP180
chip, and the second which adds configuration for the oversampling ratio
for both BMP180 and BMP280.

* v3
- use single line comment style where possible suggested by Jonathan Cameron
- remove double casts for calibration coefficients by using adequate data
  types, suggested by Jonathan Cameron
- fix oversampling register setting for bmp280, spotted by Vlad Dogaru

* v2
- split into two patches
- add error check for reading calibration data.
- s/be16_to_cpu(0)/cpu_to_be16(0)/
- default pressure oversampling ratio for bmp180 from x1 to x8
- add kconfig dependency to not select if bmp085-i2c is enabled
- create bmp280_chip_info includes all elements depending on the chip
- add ACPI ids for bmp180

Akinobu Mita (2):
  iio: pressure: bmp280: add support for BMP180
  iio: pressure: bmp280: add ability to control oversampling rate

 drivers/iio/pressure/Kconfig  |   5 +-
 drivers/iio/pressure/bmp280.c | 564 +++++++++++++++++++++++++++++++++++++++---
 2 files changed, 538 insertions(+), 31 deletions(-)

-- 
2.5.0

[PATCH v3 1/2] iio: pressure: bmp280: add support for BMP180

[Akinobu Mita]

This adds support for the BMP180 to the bmp280 iio driver.

The BMP180 has already been supported by misc/bmp085 driver but it
doesn't use iio framework.  This change adds the kconfig dependency
not to be selected both of them in order to avoid any issues.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Vlad Dogaru <vlad.dogaru@intel.com>
Cc: Christoph Mair <christoph.mair@gmail.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Peter Meerwald <pmeerw@pmeerw.net>
---
* v3
- use single line comment style where possible suggested by Jonathan Cameron
- remove double casts for calibration coefficients by using adequate data
  types, suggested by Jonathan Cameron

 drivers/iio/pressure/Kconfig  |   5 +-
 drivers/iio/pressure/bmp280.c | 367 ++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 356 insertions(+), 16 deletions(-)

diff --git a/drivers/iio/pressure/Kconfig b/drivers/iio/pressure/Kconfig
index e8f60db..31e5d36 100644
--- a/drivers/iio/pressure/Kconfig
+++ b/drivers/iio/pressure/Kconfig
@@ -6,11 +6,12 @@
 menu "Pressure sensors"
 
 config BMP280
-	tristate "Bosch Sensortec BMP280 pressure sensor driver"
+	tristate "Bosch Sensortec BMP180 and BMP280 pressure sensor driver"
 	depends on I2C
+	depends on !(BMP085_I2C=y || BMP085_I2C=m)
 	select REGMAP_I2C
 	help
-	 Say yes here to build support for Bosch Sensortec BMP280
+	 Say yes here to build support for Bosch Sensortec BMP180 and BMP280
 	 pressure and temperature sensor.
 
 	 To compile this driver as a module, choose M here: the module
diff --git a/drivers/iio/pressure/bmp280.c b/drivers/iio/pressure/bmp280.c
index a2602d8..dcf3b0a 100644
--- a/drivers/iio/pressure/bmp280.c
+++ b/drivers/iio/pressure/bmp280.c
@@ -1,12 +1,15 @@
 /*
  * Copyright (c) 2014 Intel Corporation
  *
- * Driver for Bosch Sensortec BMP280 digital pressure sensor.
+ * Driver for Bosch Sensortec BMP180 and BMP280 digital pressure sensor.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  *
+ * Datasheet:
+ * https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BMP180-DS000-121.pdf
+ * https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BMP280-DS001-12.pdf
  */
 
 #define pr_fmt(fmt) "bmp280: " fmt
@@ -15,9 +18,11 @@
 #include <linux/i2c.h>
 #include <linux/acpi.h>
 #include <linux/regmap.h>
+#include <linux/delay.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
 
+/* BMP280 specific registers */
 #define BMP280_REG_TEMP_XLSB		0xFC
 #define BMP280_REG_TEMP_LSB		0xFB
 #define BMP280_REG_TEMP_MSB		0xFA
@@ -26,10 +31,7 @@
 #define BMP280_REG_PRESS_MSB		0xF7
 
 #define BMP280_REG_CONFIG		0xF5
-#define BMP280_REG_CTRL_MEAS		0xF4
 #define BMP280_REG_STATUS		0xF3
-#define BMP280_REG_RESET		0xE0
-#define BMP280_REG_ID			0xD0
 
 #define BMP280_REG_COMP_TEMP_START	0x88
 #define BMP280_COMP_TEMP_REG_COUNT	6
@@ -65,6 +67,28 @@
 #define BMP280_MODE_FORCED		BIT(0)
 #define BMP280_MODE_NORMAL		(BIT(1) | BIT(0))
 
+/* BMP180 specific registers */
+#define BMP180_REG_OUT_XLSB		0xF8
+#define BMP180_REG_OUT_LSB		0xF7
+#define BMP180_REG_OUT_MSB		0xF6
+
+#define BMP180_REG_CALIB_START		0xAA
+#define BMP180_REG_CALIB_COUNT		22
+
+#define BMP180_MEAS_SCO			BIT(5)
+#define BMP180_MEAS_TEMP		(0x0E | BMP180_MEAS_SCO)
+#define BMP180_MEAS_PRESS_X(oss)	((oss) << 6 | 0x14 | BMP180_MEAS_SCO)
+#define BMP180_MEAS_PRESS_1X		BMP180_MEAS_PRESS_X(0)
+#define BMP180_MEAS_PRESS_2X		BMP180_MEAS_PRESS_X(1)
+#define BMP180_MEAS_PRESS_4X		BMP180_MEAS_PRESS_X(2)
+#define BMP180_MEAS_PRESS_8X		BMP180_MEAS_PRESS_X(3)
+
+/* BMP180 and BMP280 common registers */
+#define BMP280_REG_CTRL_MEAS		0xF4
+#define BMP280_REG_RESET		0xE0
+#define BMP280_REG_ID			0xD0
+
+#define BMP180_CHIP_ID			0x55
 #define BMP280_CHIP_ID			0x58
 #define BMP280_SOFT_RESET_VAL		0xB6
 
@@ -72,6 +96,7 @@ struct bmp280_data {
 	struct i2c_client *client;
 	struct mutex lock;
 	struct regmap *regmap;
+	const struct bmp280_chip_info *chip_info;
 
 	/*
 	 * Carryover value from temperature conversion, used in pressure
@@ -80,9 +105,17 @@ struct bmp280_data {
 	s32 t_fine;
 };
 
+struct bmp280_chip_info {
+	const struct regmap_config *regmap_config;
+
+	int (*chip_config)(struct bmp280_data *);
+	int (*read_temp)(struct bmp280_data *, int *);
+	int (*read_press)(struct bmp280_data *, int *, int *);
+};
+
 /*
  * These enums are used for indexing into the array of compensation
- * parameters.
+ * parameters for BMP280.
  */
 enum { T1, T2, T3 };
 enum { P1, P2, P3, P4, P5, P6, P7, P8, P9 };
@@ -290,10 +323,10 @@ static int bmp280_read_raw(struct iio_dev *indio_dev,
 	case IIO_CHAN_INFO_PROCESSED:
 		switch (chan->type) {
 		case IIO_PRESSURE:
-			ret = bmp280_read_press(data, val, val2);
+			ret = data->chip_info->read_press(data, val, val2);
 			break;
 		case IIO_TEMP:
-			ret = bmp280_read_temp(data, val);
+			ret = data->chip_info->read_temp(data, val);
 			break;
 		default:
 			ret = -EINVAL;
@@ -315,7 +348,7 @@ static const struct iio_info bmp280_info = {
 	.read_raw = &bmp280_read_raw,
 };
 
-static int bmp280_chip_init(struct bmp280_data *data)
+static int bmp280_chip_config(struct bmp280_data *data)
 {
 	int ret;
 
@@ -344,6 +377,296 @@ static int bmp280_chip_init(struct bmp280_data *data)
 	return ret;
 }
 
+static const struct bmp280_chip_info bmp280_chip_info = {
+	.regmap_config = &bmp280_regmap_config,
+	.chip_config = bmp280_chip_config,
+	.read_temp = bmp280_read_temp,
+	.read_press = bmp280_read_press,
+};
+
+static bool bmp180_is_writeable_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case BMP280_REG_CTRL_MEAS:
+	case BMP280_REG_RESET:
+		return true;
+	default:
+		return false;
+	};
+}
+
+static bool bmp180_is_volatile_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case BMP180_REG_OUT_XLSB:
+	case BMP180_REG_OUT_LSB:
+	case BMP180_REG_OUT_MSB:
+	case BMP280_REG_CTRL_MEAS:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static const struct regmap_config bmp180_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+
+	.max_register = BMP180_REG_OUT_XLSB,
+	.cache_type = REGCACHE_RBTREE,
+
+	.writeable_reg = bmp180_is_writeable_reg,
+	.volatile_reg = bmp180_is_volatile_reg,
+};
+
+static int bmp180_measure(struct bmp280_data *data, u8 ctrl_meas)
+{
+	int ret;
+	const int conversion_time_max[] = { 4500, 7500, 13500, 25500 };
+	unsigned int delay_us;
+	unsigned int ctrl;
+
+	ret = regmap_write(data->regmap, BMP280_REG_CTRL_MEAS, ctrl_meas);
+	if (ret)
+		return ret;
+
+	if (ctrl_meas == BMP180_MEAS_TEMP)
+		delay_us = 4500;
+	else
+		delay_us = conversion_time_max[ilog2(8)];
+
+	usleep_range(delay_us, delay_us + 1000);
+
+	ret = regmap_read(data->regmap, BMP280_REG_CTRL_MEAS, &ctrl);
+	if (ret)
+		return ret;
+
+	/* The value of this bit reset to "0" after conversion is complete */
+	if (ctrl & BMP180_MEAS_SCO)
+		return -EIO;
+
+	return 0;
+}
+
+static int bmp180_read_adc_temp(struct bmp280_data *data, int *val)
+{
+	int ret;
+	__be16 tmp = 0;
+
+	ret = bmp180_measure(data, BMP180_MEAS_TEMP);
+	if (ret)
+		return ret;
+
+	ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB, (u8 *)&tmp, 2);
+	if (ret)
+		return ret;
+
+	*val = be16_to_cpu(tmp);
+
+	return 0;
+}
+
+/*
+ * These enums are used for indexing into the array of calibration
+ * coefficients for BMP180.
+ */
+enum { AC1, AC2, AC3, AC4, AC5, AC6, B1, B2, MB, MC, MD };
+
+struct bmp180_calib {
+	s16 AC1;
+	s16 AC2;
+	s16 AC3;
+	u16 AC4;
+	u16 AC5;
+	u16 AC6;
+	s16 B1;
+	s16 B2;
+	s16 MB;
+	s16 MC;
+	s16 MD;
+};
+
+static int bmp180_read_calib(struct bmp280_data *data,
+			     struct bmp180_calib *calib)
+{
+	int ret;
+	int i;
+	__be16 buf[BMP180_REG_CALIB_COUNT / 2];
+
+	ret = regmap_bulk_read(data->regmap, BMP180_REG_CALIB_START, buf,
+			       sizeof(buf));
+
+	if (ret < 0)
+		return ret;
+
+	/* None of the words has the value 0 or 0xFFFF */
+	for (i = 0; i < ARRAY_SIZE(buf); i++) {
+		if (buf[i] == cpu_to_be16(0) || buf[i] == cpu_to_be16(0xffff))
+			return -EIO;
+	}
+
+	calib->AC1 = be16_to_cpu(buf[AC1]);
+	calib->AC2 = be16_to_cpu(buf[AC2]);
+	calib->AC3 = be16_to_cpu(buf[AC3]);
+	calib->AC4 = be16_to_cpu(buf[AC4]);
+	calib->AC5 = be16_to_cpu(buf[AC5]);
+	calib->AC6 = be16_to_cpu(buf[AC6]);
+	calib->B1 = be16_to_cpu(buf[B1]);
+	calib->B2 = be16_to_cpu(buf[B2]);
+	calib->MB = be16_to_cpu(buf[MB]);
+	calib->MC = be16_to_cpu(buf[MC]);
+	calib->MD = be16_to_cpu(buf[MD]);
+
+	return 0;
+}
+
+/*
+ * Returns temperature in DegC, resolution is 0.1 DegC.
+ * t_fine carries fine temperature as global value.
+ *
+ * Taken from datasheet, Section 3.5, "Calculating pressure and temperature".
+ */
+static s32 bmp180_compensate_temp(struct bmp280_data *data, s32 adc_temp)
+{
+	int ret;
+	s32 x1, x2;
+	struct bmp180_calib calib;
+
+	ret = bmp180_read_calib(data, &calib);
+	if (ret < 0) {
+		dev_err(&data->client->dev,
+			"failed to read calibration coefficients\n");
+		return ret;
+	}
+
+	x1 = ((adc_temp - calib.AC6) * calib.AC5) >> 15;
+	x2 = (calib.MC << 11) / (x1 + calib.MD);
+	data->t_fine = x1 + x2;
+
+	return (data->t_fine + 8) >> 4;
+}
+
+static int bmp180_read_temp(struct bmp280_data *data, int *val)
+{
+	int ret;
+	s32 adc_temp, comp_temp;
+
+	ret = bmp180_read_adc_temp(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;
+}
+
+static int bmp180_read_adc_press(struct bmp280_data *data, int *val)
+{
+	int ret;
+	__be32 tmp = 0;
+	u8 oss = ilog2(8);
+
+	ret = bmp180_measure(data, BMP180_MEAS_PRESS_X(oss));
+	if (ret)
+		return ret;
+
+	ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB, (u8 *)&tmp, 3);
+	if (ret)
+		return ret;
+
+	*val = (be32_to_cpu(tmp) >> 8) >> (8 - oss);
+
+	return 0;
+}
+
+/*
+ * Returns pressure in Pa, resolution is 1 Pa.
+ *
+ * Taken from datasheet, Section 3.5, "Calculating pressure and temperature".
+ */
+static u32 bmp180_compensate_press(struct bmp280_data *data, s32 adc_press)
+{
+	int ret;
+	s32 x1, x2, x3, p;
+	s32 b3, b6;
+	u32 b4, b7;
+	s32 oss = ilog2(8);
+	struct bmp180_calib calib;
+
+	ret = bmp180_read_calib(data, &calib);
+	if (ret < 0) {
+		dev_err(&data->client->dev,
+			"failed to read calibration coefficients\n");
+		return ret;
+	}
+
+	b6 = data->t_fine - 4000;
+	x1 = (calib.B2 * (b6 * b6 >> 12)) >> 11;
+	x2 = calib.AC2 * b6 >> 11;
+	x3 = x1 + x2;
+	b3 = ((((s32)calib.AC1 * 4 + x3) << oss) + 2) / 4;
+	x1 = calib.AC3 * b6 >> 13;
+	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);
+	if (b7 < 0x80000000)
+		p = (b7 * 2) / b4;
+	else
+		p = (b7 / b4) * 2;
+
+	x1 = (p >> 8) * (p >> 8);
+	x1 = (x1 * 3038) >> 16;
+	x2 = (-7357 * p) >> 16;
+
+	return p + ((x1 + x2 + 3791) >> 4);
+}
+
+static int bmp180_read_press(struct bmp280_data *data,
+			     int *val, int *val2)
+{
+	int ret;
+	s32 adc_press;
+	u32 comp_press;
+
+	/* Read and compensate temperature so we get a reading of t_fine. */
+	ret = bmp180_read_temp(data, NULL);
+	if (ret)
+		return ret;
+
+	ret = bmp180_read_adc_press(data, &adc_press);
+	if (ret)
+		return ret;
+
+	comp_press = bmp180_compensate_press(data, adc_press);
+
+	*val = comp_press;
+	*val2 = 1000;
+
+	return IIO_VAL_FRACTIONAL;
+}
+
+static int bmp180_chip_config(struct bmp280_data *data)
+{
+	return 0;
+}
+
+static const struct bmp280_chip_info bmp180_chip_info = {
+	.regmap_config = &bmp180_regmap_config,
+	.chip_config = bmp180_chip_config,
+	.read_temp = bmp180_read_temp,
+	.read_press = bmp180_read_press,
+};
+
 static int bmp280_probe(struct i2c_client *client,
 			const struct i2c_device_id *id)
 {
@@ -367,7 +690,19 @@ static int bmp280_probe(struct i2c_client *client,
 	indio_dev->info = &bmp280_info;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 
-	data->regmap = devm_regmap_init_i2c(client, &bmp280_regmap_config);
+	switch (id->driver_data) {
+	case BMP180_CHIP_ID:
+		data->chip_info = &bmp180_chip_info;
+		break;
+	case BMP280_CHIP_ID:
+		data->chip_info = &bmp280_chip_info;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	data->regmap = devm_regmap_init_i2c(client,
+					data->chip_info->regmap_config);
 	if (IS_ERR(data->regmap)) {
 		dev_err(&client->dev, "failed to allocate register map\n");
 		return PTR_ERR(data->regmap);
@@ -376,13 +711,13 @@ static int bmp280_probe(struct i2c_client *client,
 	ret = regmap_read(data->regmap, BMP280_REG_ID, &chip_id);
 	if (ret < 0)
 		return ret;
-	if (chip_id != BMP280_CHIP_ID) {
+	if (chip_id != id->driver_data) {
 		dev_err(&client->dev, "bad chip id.  expected %x got %x\n",
 			BMP280_CHIP_ID, chip_id);
 		return -EINVAL;
 	}
 
-	ret = bmp280_chip_init(data);
+	ret = data->chip_info->chip_config(data);
 	if (ret < 0)
 		return ret;
 
@@ -390,13 +725,17 @@ static int bmp280_probe(struct i2c_client *client,
 }
 
 static const struct acpi_device_id bmp280_acpi_match[] = {
-	{"BMP0280", 0},
+	{"BMP0280", BMP280_CHIP_ID },
+	{"BMP0180", BMP180_CHIP_ID },
+	{"BMP0085", BMP180_CHIP_ID },
 	{ },
 };
 MODULE_DEVICE_TABLE(acpi, bmp280_acpi_match);
 
 static const struct i2c_device_id bmp280_id[] = {
-	{"bmp280", 0},
+	{"bmp280", BMP280_CHIP_ID },
+	{"bmp180", BMP180_CHIP_ID },
+	{"bmp085", BMP180_CHIP_ID },
 	{ },
 };
 MODULE_DEVICE_TABLE(i2c, bmp280_id);
@@ -412,5 +751,5 @@ static struct i2c_driver bmp280_driver = {
 module_i2c_driver(bmp280_driver);
 
 MODULE_AUTHOR("Vlad Dogaru <vlad.dogaru@intel.com>");
-MODULE_DESCRIPTION("Driver for Bosch Sensortec BMP280 pressure and temperature sensor");
+MODULE_DESCRIPTION("Driver for Bosch Sensortec BMP180/BMP280 pressure and temperature sensor");
 MODULE_LICENSE("GPL v2");
-- 
2.5.0

Re: [PATCH v3 1/2] iio: pressure: bmp280: add support for BMP180

[Vlad Dogaru]

On Sun, Apr 24, 2016 at 10:52:10PM +0900, Akinobu Mita wrote:
> This adds support for the BMP180 to the bmp280 iio driver.
> 
> The BMP180 has already been supported by misc/bmp085 driver but it
> doesn't use iio framework.  This change adds the kconfig dependency
> not to be selected both of them in order to avoid any issues.
> 
> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
> Cc: Vlad Dogaru <vlad.dogaru@intel.com>
> Cc: Christoph Mair <christoph.mair@gmail.com>
> Cc: Jonathan Cameron <jic23@kernel.org>
> Cc: Hartmut Knaack <knaack.h@gmx.de>
> Cc: Lars-Peter Clausen <lars@metafoo.de>
> Cc: Peter Meerwald <pmeerw@pmeerw.net>

Acked-by: Vlad Dogaru <vlad.dogaru@intel.com>

Thanks for addressing my comments.

> ---
> * v3
> - use single line comment style where possible suggested by Jonathan Cameron
> - remove double casts for calibration coefficients by using adequate data
>   types, suggested by Jonathan Cameron
> 
>  drivers/iio/pressure/Kconfig  |   5 +-
>  drivers/iio/pressure/bmp280.c | 367 ++++++++++++++++++++++++++++++++++++++++--
>  2 files changed, 356 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/iio/pressure/Kconfig b/drivers/iio/pressure/Kconfig
> index e8f60db..31e5d36 100644
> --- a/drivers/iio/pressure/Kconfig
> +++ b/drivers/iio/pressure/Kconfig
> @@ -6,11 +6,12 @@
>  menu "Pressure sensors"
>  
>  config BMP280
> -	tristate "Bosch Sensortec BMP280 pressure sensor driver"
> +	tristate "Bosch Sensortec BMP180 and BMP280 pressure sensor driver"
>  	depends on I2C
> +	depends on !(BMP085_I2C=y || BMP085_I2C=m)
>  	select REGMAP_I2C
>  	help
> -	 Say yes here to build support for Bosch Sensortec BMP280
> +	 Say yes here to build support for Bosch Sensortec BMP180 and BMP280
>  	 pressure and temperature sensor.
>  
>  	 To compile this driver as a module, choose M here: the module
> diff --git a/drivers/iio/pressure/bmp280.c b/drivers/iio/pressure/bmp280.c
> index a2602d8..dcf3b0a 100644
> --- a/drivers/iio/pressure/bmp280.c
> +++ b/drivers/iio/pressure/bmp280.c
> @@ -1,12 +1,15 @@
>  /*
>   * Copyright (c) 2014 Intel Corporation
>   *
> - * Driver for Bosch Sensortec BMP280 digital pressure sensor.
> + * Driver for Bosch Sensortec BMP180 and BMP280 digital pressure sensor.
>   *
>   * This program is free software; you can redistribute it and/or modify
>   * it under the terms of the GNU General Public License version 2 as
>   * published by the Free Software Foundation.
>   *
> + * Datasheet:
> + * https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BMP180-DS000-121.pdf
> + * https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BMP280-DS001-12.pdf
>   */
>  
>  #define pr_fmt(fmt) "bmp280: " fmt
> @@ -15,9 +18,11 @@
>  #include <linux/i2c.h>
>  #include <linux/acpi.h>
>  #include <linux/regmap.h>
> +#include <linux/delay.h>
>  #include <linux/iio/iio.h>
>  #include <linux/iio/sysfs.h>
>  
> +/* BMP280 specific registers */
>  #define BMP280_REG_TEMP_XLSB		0xFC
>  #define BMP280_REG_TEMP_LSB		0xFB
>  #define BMP280_REG_TEMP_MSB		0xFA
> @@ -26,10 +31,7 @@
>  #define BMP280_REG_PRESS_MSB		0xF7
>  
>  #define BMP280_REG_CONFIG		0xF5
> -#define BMP280_REG_CTRL_MEAS		0xF4
>  #define BMP280_REG_STATUS		0xF3
> -#define BMP280_REG_RESET		0xE0
> -#define BMP280_REG_ID			0xD0
>  
>  #define BMP280_REG_COMP_TEMP_START	0x88
>  #define BMP280_COMP_TEMP_REG_COUNT	6
> @@ -65,6 +67,28 @@
>  #define BMP280_MODE_FORCED		BIT(0)
>  #define BMP280_MODE_NORMAL		(BIT(1) | BIT(0))
>  
> +/* BMP180 specific registers */
> +#define BMP180_REG_OUT_XLSB		0xF8
> +#define BMP180_REG_OUT_LSB		0xF7
> +#define BMP180_REG_OUT_MSB		0xF6
> +
> +#define BMP180_REG_CALIB_START		0xAA
> +#define BMP180_REG_CALIB_COUNT		22
> +
> +#define BMP180_MEAS_SCO			BIT(5)
> +#define BMP180_MEAS_TEMP		(0x0E | BMP180_MEAS_SCO)
> +#define BMP180_MEAS_PRESS_X(oss)	((oss) << 6 | 0x14 | BMP180_MEAS_SCO)
> +#define BMP180_MEAS_PRESS_1X		BMP180_MEAS_PRESS_X(0)
> +#define BMP180_MEAS_PRESS_2X		BMP180_MEAS_PRESS_X(1)
> +#define BMP180_MEAS_PRESS_4X		BMP180_MEAS_PRESS_X(2)
> +#define BMP180_MEAS_PRESS_8X		BMP180_MEAS_PRESS_X(3)
> +
> +/* BMP180 and BMP280 common registers */
> +#define BMP280_REG_CTRL_MEAS		0xF4
> +#define BMP280_REG_RESET		0xE0
> +#define BMP280_REG_ID			0xD0
> +
> +#define BMP180_CHIP_ID			0x55
>  #define BMP280_CHIP_ID			0x58
>  #define BMP280_SOFT_RESET_VAL		0xB6
>  
> @@ -72,6 +96,7 @@ struct bmp280_data {
>  	struct i2c_client *client;
>  	struct mutex lock;
>  	struct regmap *regmap;
> +	const struct bmp280_chip_info *chip_info;
>  
>  	/*
>  	 * Carryover value from temperature conversion, used in pressure
> @@ -80,9 +105,17 @@ struct bmp280_data {
>  	s32 t_fine;
>  };
>  
> +struct bmp280_chip_info {
> +	const struct regmap_config *regmap_config;
> +
> +	int (*chip_config)(struct bmp280_data *);
> +	int (*read_temp)(struct bmp280_data *, int *);
> +	int (*read_press)(struct bmp280_data *, int *, int *);
> +};
> +
>  /*
>   * These enums are used for indexing into the array of compensation
> - * parameters.
> + * parameters for BMP280.
>   */
>  enum { T1, T2, T3 };
>  enum { P1, P2, P3, P4, P5, P6, P7, P8, P9 };
> @@ -290,10 +323,10 @@ static int bmp280_read_raw(struct iio_dev *indio_dev,
>  	case IIO_CHAN_INFO_PROCESSED:
>  		switch (chan->type) {
>  		case IIO_PRESSURE:
> -			ret = bmp280_read_press(data, val, val2);
> +			ret = data->chip_info->read_press(data, val, val2);
>  			break;
>  		case IIO_TEMP:
> -			ret = bmp280_read_temp(data, val);
> +			ret = data->chip_info->read_temp(data, val);
>  			break;
>  		default:
>  			ret = -EINVAL;
> @@ -315,7 +348,7 @@ static const struct iio_info bmp280_info = {
>  	.read_raw = &bmp280_read_raw,
>  };
>  
> -static int bmp280_chip_init(struct bmp280_data *data)
> +static int bmp280_chip_config(struct bmp280_data *data)
>  {
>  	int ret;
>  
> @@ -344,6 +377,296 @@ static int bmp280_chip_init(struct bmp280_data *data)
>  	return ret;
>  }
>  
> +static const struct bmp280_chip_info bmp280_chip_info = {
> +	.regmap_config = &bmp280_regmap_config,
> +	.chip_config = bmp280_chip_config,
> +	.read_temp = bmp280_read_temp,
> +	.read_press = bmp280_read_press,
> +};
> +
> +static bool bmp180_is_writeable_reg(struct device *dev, unsigned int reg)
> +{
> +	switch (reg) {
> +	case BMP280_REG_CTRL_MEAS:
> +	case BMP280_REG_RESET:
> +		return true;
> +	default:
> +		return false;
> +	};
> +}
> +
> +static bool bmp180_is_volatile_reg(struct device *dev, unsigned int reg)
> +{
> +	switch (reg) {
> +	case BMP180_REG_OUT_XLSB:
> +	case BMP180_REG_OUT_LSB:
> +	case BMP180_REG_OUT_MSB:
> +	case BMP280_REG_CTRL_MEAS:
> +		return true;
> +	default:
> +		return false;
> +	}
> +}
> +
> +static const struct regmap_config bmp180_regmap_config = {
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +
> +	.max_register = BMP180_REG_OUT_XLSB,
> +	.cache_type = REGCACHE_RBTREE,
> +
> +	.writeable_reg = bmp180_is_writeable_reg,
> +	.volatile_reg = bmp180_is_volatile_reg,
> +};
> +
> +static int bmp180_measure(struct bmp280_data *data, u8 ctrl_meas)
> +{
> +	int ret;
> +	const int conversion_time_max[] = { 4500, 7500, 13500, 25500 };
> +	unsigned int delay_us;
> +	unsigned int ctrl;
> +
> +	ret = regmap_write(data->regmap, BMP280_REG_CTRL_MEAS, ctrl_meas);
> +	if (ret)
> +		return ret;
> +
> +	if (ctrl_meas == BMP180_MEAS_TEMP)
> +		delay_us = 4500;
> +	else
> +		delay_us = conversion_time_max[ilog2(8)];
> +
> +	usleep_range(delay_us, delay_us + 1000);
> +
> +	ret = regmap_read(data->regmap, BMP280_REG_CTRL_MEAS, &ctrl);
> +	if (ret)
> +		return ret;
> +
> +	/* The value of this bit reset to "0" after conversion is complete */
> +	if (ctrl & BMP180_MEAS_SCO)
> +		return -EIO;
> +
> +	return 0;
> +}
> +
> +static int bmp180_read_adc_temp(struct bmp280_data *data, int *val)
> +{
> +	int ret;
> +	__be16 tmp = 0;
> +
> +	ret = bmp180_measure(data, BMP180_MEAS_TEMP);
> +	if (ret)
> +		return ret;
> +
> +	ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB, (u8 *)&tmp, 2);
> +	if (ret)
> +		return ret;
> +
> +	*val = be16_to_cpu(tmp);
> +
> +	return 0;
> +}
> +
> +/*
> + * These enums are used for indexing into the array of calibration
> + * coefficients for BMP180.
> + */
> +enum { AC1, AC2, AC3, AC4, AC5, AC6, B1, B2, MB, MC, MD };
> +
> +struct bmp180_calib {
> +	s16 AC1;
> +	s16 AC2;
> +	s16 AC3;
> +	u16 AC4;
> +	u16 AC5;
> +	u16 AC6;
> +	s16 B1;
> +	s16 B2;
> +	s16 MB;
> +	s16 MC;
> +	s16 MD;
> +};
> +
> +static int bmp180_read_calib(struct bmp280_data *data,
> +			     struct bmp180_calib *calib)
> +{
> +	int ret;
> +	int i;
> +	__be16 buf[BMP180_REG_CALIB_COUNT / 2];
> +
> +	ret = regmap_bulk_read(data->regmap, BMP180_REG_CALIB_START, buf,
> +			       sizeof(buf));
> +
> +	if (ret < 0)
> +		return ret;
> +
> +	/* None of the words has the value 0 or 0xFFFF */
> +	for (i = 0; i < ARRAY_SIZE(buf); i++) {
> +		if (buf[i] == cpu_to_be16(0) || buf[i] == cpu_to_be16(0xffff))
> +			return -EIO;
> +	}
> +
> +	calib->AC1 = be16_to_cpu(buf[AC1]);
> +	calib->AC2 = be16_to_cpu(buf[AC2]);
> +	calib->AC3 = be16_to_cpu(buf[AC3]);
> +	calib->AC4 = be16_to_cpu(buf[AC4]);
> +	calib->AC5 = be16_to_cpu(buf[AC5]);
> +	calib->AC6 = be16_to_cpu(buf[AC6]);
> +	calib->B1 = be16_to_cpu(buf[B1]);
> +	calib->B2 = be16_to_cpu(buf[B2]);
> +	calib->MB = be16_to_cpu(buf[MB]);
> +	calib->MC = be16_to_cpu(buf[MC]);
> +	calib->MD = be16_to_cpu(buf[MD]);
> +
> +	return 0;
> +}
> +
> +/*
> + * Returns temperature in DegC, resolution is 0.1 DegC.
> + * t_fine carries fine temperature as global value.
> + *
> + * Taken from datasheet, Section 3.5, "Calculating pressure and temperature".
> + */
> +static s32 bmp180_compensate_temp(struct bmp280_data *data, s32 adc_temp)
> +{
> +	int ret;
> +	s32 x1, x2;
> +	struct bmp180_calib calib;
> +
> +	ret = bmp180_read_calib(data, &calib);
> +	if (ret < 0) {
> +		dev_err(&data->client->dev,
> +			"failed to read calibration coefficients\n");
> +		return ret;
> +	}
> +
> +	x1 = ((adc_temp - calib.AC6) * calib.AC5) >> 15;
> +	x2 = (calib.MC << 11) / (x1 + calib.MD);
> +	data->t_fine = x1 + x2;
> +
> +	return (data->t_fine + 8) >> 4;
> +}
> +
> +static int bmp180_read_temp(struct bmp280_data *data, int *val)
> +{
> +	int ret;
> +	s32 adc_temp, comp_temp;
> +
> +	ret = bmp180_read_adc_temp(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;
> +}
> +
> +static int bmp180_read_adc_press(struct bmp280_data *data, int *val)
> +{
> +	int ret;
> +	__be32 tmp = 0;
> +	u8 oss = ilog2(8);
> +
> +	ret = bmp180_measure(data, BMP180_MEAS_PRESS_X(oss));
> +	if (ret)
> +		return ret;
> +
> +	ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB, (u8 *)&tmp, 3);
> +	if (ret)
> +		return ret;
> +
> +	*val = (be32_to_cpu(tmp) >> 8) >> (8 - oss);
> +
> +	return 0;
> +}
> +
> +/*
> + * Returns pressure in Pa, resolution is 1 Pa.
> + *
> + * Taken from datasheet, Section 3.5, "Calculating pressure and temperature".
> + */
> +static u32 bmp180_compensate_press(struct bmp280_data *data, s32 adc_press)
> +{
> +	int ret;
> +	s32 x1, x2, x3, p;
> +	s32 b3, b6;
> +	u32 b4, b7;
> +	s32 oss = ilog2(8);
> +	struct bmp180_calib calib;
> +
> +	ret = bmp180_read_calib(data, &calib);
> +	if (ret < 0) {
> +		dev_err(&data->client->dev,
> +			"failed to read calibration coefficients\n");
> +		return ret;
> +	}
> +
> +	b6 = data->t_fine - 4000;
> +	x1 = (calib.B2 * (b6 * b6 >> 12)) >> 11;
> +	x2 = calib.AC2 * b6 >> 11;
> +	x3 = x1 + x2;
> +	b3 = ((((s32)calib.AC1 * 4 + x3) << oss) + 2) / 4;
> +	x1 = calib.AC3 * b6 >> 13;
> +	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);
> +	if (b7 < 0x80000000)
> +		p = (b7 * 2) / b4;
> +	else
> +		p = (b7 / b4) * 2;
> +
> +	x1 = (p >> 8) * (p >> 8);
> +	x1 = (x1 * 3038) >> 16;
> +	x2 = (-7357 * p) >> 16;
> +
> +	return p + ((x1 + x2 + 3791) >> 4);
> +}
> +
> +static int bmp180_read_press(struct bmp280_data *data,
> +			     int *val, int *val2)
> +{
> +	int ret;
> +	s32 adc_press;
> +	u32 comp_press;
> +
> +	/* Read and compensate temperature so we get a reading of t_fine. */
> +	ret = bmp180_read_temp(data, NULL);
> +	if (ret)
> +		return ret;
> +
> +	ret = bmp180_read_adc_press(data, &adc_press);
> +	if (ret)
> +		return ret;
> +
> +	comp_press = bmp180_compensate_press(data, adc_press);
> +
> +	*val = comp_press;
> +	*val2 = 1000;
> +
> +	return IIO_VAL_FRACTIONAL;
> +}
> +
> +static int bmp180_chip_config(struct bmp280_data *data)
> +{
> +	return 0;
> +}
> +
> +static const struct bmp280_chip_info bmp180_chip_info = {
> +	.regmap_config = &bmp180_regmap_config,
> +	.chip_config = bmp180_chip_config,
> +	.read_temp = bmp180_read_temp,
> +	.read_press = bmp180_read_press,
> +};
> +
>  static int bmp280_probe(struct i2c_client *client,
>  			const struct i2c_device_id *id)
>  {
> @@ -367,7 +690,19 @@ static int bmp280_probe(struct i2c_client *client,
>  	indio_dev->info = &bmp280_info;
>  	indio_dev->modes = INDIO_DIRECT_MODE;
>  
> -	data->regmap = devm_regmap_init_i2c(client, &bmp280_regmap_config);
> +	switch (id->driver_data) {
> +	case BMP180_CHIP_ID:
> +		data->chip_info = &bmp180_chip_info;
> +		break;
> +	case BMP280_CHIP_ID:
> +		data->chip_info = &bmp280_chip_info;
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	data->regmap = devm_regmap_init_i2c(client,
> +					data->chip_info->regmap_config);
>  	if (IS_ERR(data->regmap)) {
>  		dev_err(&client->dev, "failed to allocate register map\n");
>  		return PTR_ERR(data->regmap);
> @@ -376,13 +711,13 @@ static int bmp280_probe(struct i2c_client *client,
>  	ret = regmap_read(data->regmap, BMP280_REG_ID, &chip_id);
>  	if (ret < 0)
>  		return ret;
> -	if (chip_id != BMP280_CHIP_ID) {
> +	if (chip_id != id->driver_data) {
>  		dev_err(&client->dev, "bad chip id.  expected %x got %x\n",
>  			BMP280_CHIP_ID, chip_id);
>  		return -EINVAL;
>  	}
>  
> -	ret = bmp280_chip_init(data);
> +	ret = data->chip_info->chip_config(data);
>  	if (ret < 0)
>  		return ret;
>  
> @@ -390,13 +725,17 @@ static int bmp280_probe(struct i2c_client *client,
>  }
>  
>  static const struct acpi_device_id bmp280_acpi_match[] = {
> -	{"BMP0280", 0},
> +	{"BMP0280", BMP280_CHIP_ID },
> +	{"BMP0180", BMP180_CHIP_ID },
> +	{"BMP0085", BMP180_CHIP_ID },
>  	{ },
>  };
>  MODULE_DEVICE_TABLE(acpi, bmp280_acpi_match);
>  
>  static const struct i2c_device_id bmp280_id[] = {
> -	{"bmp280", 0},
> +	{"bmp280", BMP280_CHIP_ID },
> +	{"bmp180", BMP180_CHIP_ID },
> +	{"bmp085", BMP180_CHIP_ID },
>  	{ },
>  };
>  MODULE_DEVICE_TABLE(i2c, bmp280_id);
> @@ -412,5 +751,5 @@ static struct i2c_driver bmp280_driver = {
>  module_i2c_driver(bmp280_driver);
>  
>  MODULE_AUTHOR("Vlad Dogaru <vlad.dogaru@intel.com>");
> -MODULE_DESCRIPTION("Driver for Bosch Sensortec BMP280 pressure and temperature sensor");
> +MODULE_DESCRIPTION("Driver for Bosch Sensortec BMP180/BMP280 pressure and temperature sensor");
>  MODULE_LICENSE("GPL v2");
> -- 
> 2.5.0
> 

Re: [PATCH v3 1/2] iio: pressure: bmp280: add support for BMP180

[Matt Ranostay]

On Sun, Apr 24, 2016 at 6:52 AM, Akinobu Mita <akinobu.mita@gmail.com> wrote:
> This adds support for the BMP180 to the bmp280 iio driver.
>
> The BMP180 has already been supported by misc/bmp085 driver but it
> doesn't use iio framework.  This change adds the kconfig dependency
> not to be selected both of them in order to avoid any issues.
>
> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
> Cc: Vlad Dogaru <vlad.dogaru@intel.com>
> Cc: Christoph Mair <christoph.mair@gmail.com>
> Cc: Jonathan Cameron <jic23@kernel.org>
> Cc: Hartmut Knaack <knaack.h@gmx.de>
> Cc: Lars-Peter Clausen <lars@metafoo.de>
> Cc: Peter Meerwald <pmeerw@pmeerw.net>
> ---
> * v3
> - use single line comment style where possible suggested by Jonathan Cameron
> - remove double casts for calibration coefficients by using adequate data
>   types, suggested by Jonathan Cameron
>
>  drivers/iio/pressure/Kconfig  |   5 +-
>  drivers/iio/pressure/bmp280.c | 367 ++++++++++++++++++++++++++++++++++++++++--
>  2 files changed, 356 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/iio/pressure/Kconfig b/drivers/iio/pressure/Kconfig
> index e8f60db..31e5d36 100644
> --- a/drivers/iio/pressure/Kconfig
> +++ b/drivers/iio/pressure/Kconfig
> @@ -6,11 +6,12 @@
>  menu "Pressure sensors"
>
>  config BMP280
> -       tristate "Bosch Sensortec BMP280 pressure sensor driver"
> +       tristate "Bosch Sensortec BMP180 and BMP280 pressure sensor driver"
>         depends on I2C
> +       depends on !(BMP085_I2C=y || BMP085_I2C=m)
>         select REGMAP_I2C
>         help
> -        Say yes here to build support for Bosch Sensortec BMP280
> +        Say yes here to build support for Bosch Sensortec BMP180 and BMP280
>          pressure and temperature sensor.
>
>          To compile this driver as a module, choose M here: the module
> diff --git a/drivers/iio/pressure/bmp280.c b/drivers/iio/pressure/bmp280.c
> index a2602d8..dcf3b0a 100644
> --- a/drivers/iio/pressure/bmp280.c
> +++ b/drivers/iio/pressure/bmp280.c
> @@ -1,12 +1,15 @@
>  /*
>   * Copyright (c) 2014 Intel Corporation
>   *
> - * Driver for Bosch Sensortec BMP280 digital pressure sensor.
> + * Driver for Bosch Sensortec BMP180 and BMP280 digital pressure sensor.
>   *
>   * This program is free software; you can redistribute it and/or modify
>   * it under the terms of the GNU General Public License version 2 as
>   * published by the Free Software Foundation.
>   *
> + * Datasheet:
> + * https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BMP180-DS000-121.pdf
> + * https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BMP280-DS001-12.pdf
>   */
>
>  #define pr_fmt(fmt) "bmp280: " fmt
> @@ -15,9 +18,11 @@
>  #include <linux/i2c.h>
>  #include <linux/acpi.h>
>  #include <linux/regmap.h>
> +#include <linux/delay.h>
>  #include <linux/iio/iio.h>
>  #include <linux/iio/sysfs.h>
>
> +/* BMP280 specific registers */
>  #define BMP280_REG_TEMP_XLSB           0xFC
>  #define BMP280_REG_TEMP_LSB            0xFB
>  #define BMP280_REG_TEMP_MSB            0xFA
> @@ -26,10 +31,7 @@
>  #define BMP280_REG_PRESS_MSB           0xF7
>
>  #define BMP280_REG_CONFIG              0xF5
> -#define BMP280_REG_CTRL_MEAS           0xF4
>  #define BMP280_REG_STATUS              0xF3
> -#define BMP280_REG_RESET               0xE0
> -#define BMP280_REG_ID                  0xD0
>
>  #define BMP280_REG_COMP_TEMP_START     0x88
>  #define BMP280_COMP_TEMP_REG_COUNT     6
> @@ -65,6 +67,28 @@
>  #define BMP280_MODE_FORCED             BIT(0)
>  #define BMP280_MODE_NORMAL             (BIT(1) | BIT(0))
>
> +/* BMP180 specific registers */
> +#define BMP180_REG_OUT_XLSB            0xF8
> +#define BMP180_REG_OUT_LSB             0xF7
> +#define BMP180_REG_OUT_MSB             0xF6
> +
> +#define BMP180_REG_CALIB_START         0xAA
> +#define BMP180_REG_CALIB_COUNT         22
> +
> +#define BMP180_MEAS_SCO                        BIT(5)
> +#define BMP180_MEAS_TEMP               (0x0E | BMP180_MEAS_SCO)
> +#define BMP180_MEAS_PRESS_X(oss)       ((oss) << 6 | 0x14 | BMP180_MEAS_SCO)
> +#define BMP180_MEAS_PRESS_1X           BMP180_MEAS_PRESS_X(0)
> +#define BMP180_MEAS_PRESS_2X           BMP180_MEAS_PRESS_X(1)
> +#define BMP180_MEAS_PRESS_4X           BMP180_MEAS_PRESS_X(2)
> +#define BMP180_MEAS_PRESS_8X           BMP180_MEAS_PRESS_X(3)
> +
> +/* BMP180 and BMP280 common registers */
> +#define BMP280_REG_CTRL_MEAS           0xF4
> +#define BMP280_REG_RESET               0xE0
> +#define BMP280_REG_ID                  0xD0
> +
> +#define BMP180_CHIP_ID                 0x55
>  #define BMP280_CHIP_ID                 0x58
>  #define BMP280_SOFT_RESET_VAL          0xB6
>
> @@ -72,6 +96,7 @@ struct bmp280_data {
>         struct i2c_client *client;
>         struct mutex lock;
>         struct regmap *regmap;
> +       const struct bmp280_chip_info *chip_info;
>
>         /*
>          * Carryover value from temperature conversion, used in pressure
> @@ -80,9 +105,17 @@ struct bmp280_data {
>         s32 t_fine;
>  };
>
> +struct bmp280_chip_info {
> +       const struct regmap_config *regmap_config;
> +
> +       int (*chip_config)(struct bmp280_data *);
> +       int (*read_temp)(struct bmp280_data *, int *);
> +       int (*read_press)(struct bmp280_data *, int *, int *);
> +};
> +
>  /*
>   * These enums are used for indexing into the array of compensation
> - * parameters.
> + * parameters for BMP280.
>   */
>  enum { T1, T2, T3 };
>  enum { P1, P2, P3, P4, P5, P6, P7, P8, P9 };
> @@ -290,10 +323,10 @@ static int bmp280_read_raw(struct iio_dev *indio_dev,
>         case IIO_CHAN_INFO_PROCESSED:
>                 switch (chan->type) {
>                 case IIO_PRESSURE:
> -                       ret = bmp280_read_press(data, val, val2);
> +                       ret = data->chip_info->read_press(data, val, val2);
>                         break;
>                 case IIO_TEMP:
> -                       ret = bmp280_read_temp(data, val);
> +                       ret = data->chip_info->read_temp(data, val);
>                         break;
>                 default:
>                         ret = -EINVAL;
> @@ -315,7 +348,7 @@ static const struct iio_info bmp280_info = {
>         .read_raw = &bmp280_read_raw,
>  };
>
> -static int bmp280_chip_init(struct bmp280_data *data)
> +static int bmp280_chip_config(struct bmp280_data *data)
>  {
>         int ret;
>
> @@ -344,6 +377,296 @@ static int bmp280_chip_init(struct bmp280_data *data)
>         return ret;
>  }
>
> +static const struct bmp280_chip_info bmp280_chip_info = {
> +       .regmap_config = &bmp280_regmap_config,
> +       .chip_config = bmp280_chip_config,
> +       .read_temp = bmp280_read_temp,
> +       .read_press = bmp280_read_press,
> +};
> +
> +static bool bmp180_is_writeable_reg(struct device *dev, unsigned int reg)
> +{
> +       switch (reg) {
> +       case BMP280_REG_CTRL_MEAS:
> +       case BMP280_REG_RESET:
> +               return true;
> +       default:
> +               return false;
> +       };
> +}
> +
> +static bool bmp180_is_volatile_reg(struct device *dev, unsigned int reg)
> +{
> +       switch (reg) {
> +       case BMP180_REG_OUT_XLSB:
> +       case BMP180_REG_OUT_LSB:
> +       case BMP180_REG_OUT_MSB:
> +       case BMP280_REG_CTRL_MEAS:
> +               return true;
> +       default:
> +               return false;
> +       }
> +}
> +
> +static const struct regmap_config bmp180_regmap_config = {
> +       .reg_bits = 8,
> +       .val_bits = 8,
> +
> +       .max_register = BMP180_REG_OUT_XLSB,
> +       .cache_type = REGCACHE_RBTREE,
> +
> +       .writeable_reg = bmp180_is_writeable_reg,
> +       .volatile_reg = bmp180_is_volatile_reg,
> +};
> +
> +static int bmp180_measure(struct bmp280_data *data, u8 ctrl_meas)
> +{
> +       int ret;
> +       const int conversion_time_max[] = { 4500, 7500, 13500, 25500 };
> +       unsigned int delay_us;
> +       unsigned int ctrl;
> +
> +       ret = regmap_write(data->regmap, BMP280_REG_CTRL_MEAS, ctrl_meas);
> +       if (ret)
> +               return ret;
> +
> +       if (ctrl_meas == BMP180_MEAS_TEMP)
> +               delay_us = 4500;
> +       else
> +               delay_us = conversion_time_max[ilog2(8)];
> +
> +       usleep_range(delay_us, delay_us + 1000);
> +
> +       ret = regmap_read(data->regmap, BMP280_REG_CTRL_MEAS, &ctrl);
> +       if (ret)
> +               return ret;
> +
> +       /* The value of this bit reset to "0" after conversion is complete */
> +       if (ctrl & BMP180_MEAS_SCO)
> +               return -EIO;
> +
> +       return 0;
> +}
> +
> +static int bmp180_read_adc_temp(struct bmp280_data *data, int *val)
> +{
> +       int ret;
> +       __be16 tmp = 0;
> +
> +       ret = bmp180_measure(data, BMP180_MEAS_TEMP);
> +       if (ret)
> +               return ret;
> +
> +       ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB, (u8 *)&tmp, 2);
> +       if (ret)
> +               return ret;
> +
> +       *val = be16_to_cpu(tmp);
> +
> +       return 0;
> +}
> +
> +/*
> + * These enums are used for indexing into the array of calibration
> + * coefficients for BMP180.
> + */
> +enum { AC1, AC2, AC3, AC4, AC5, AC6, B1, B2, MB, MC, MD };
> +
> +struct bmp180_calib {
> +       s16 AC1;
> +       s16 AC2;
> +       s16 AC3;
> +       u16 AC4;
> +       u16 AC5;
> +       u16 AC6;
> +       s16 B1;
> +       s16 B2;
> +       s16 MB;
> +       s16 MC;
> +       s16 MD;
> +};
> +
> +static int bmp180_read_calib(struct bmp280_data *data,
> +                            struct bmp180_calib *calib)
> +{
> +       int ret;
> +       int i;
> +       __be16 buf[BMP180_REG_CALIB_COUNT / 2];
> +
> +       ret = regmap_bulk_read(data->regmap, BMP180_REG_CALIB_START, buf,
> +                              sizeof(buf));
> +
> +       if (ret < 0)
> +               return ret;
> +
> +       /* None of the words has the value 0 or 0xFFFF */
> +       for (i = 0; i < ARRAY_SIZE(buf); i++) {
> +               if (buf[i] == cpu_to_be16(0) || buf[i] == cpu_to_be16(0xffff))
> +                       return -EIO;
> +       }
> +
> +       calib->AC1 = be16_to_cpu(buf[AC1]);
> +       calib->AC2 = be16_to_cpu(buf[AC2]);
> +       calib->AC3 = be16_to_cpu(buf[AC3]);
> +       calib->AC4 = be16_to_cpu(buf[AC4]);
> +       calib->AC5 = be16_to_cpu(buf[AC5]);
> +       calib->AC6 = be16_to_cpu(buf[AC6]);
> +       calib->B1 = be16_to_cpu(buf[B1]);
> +       calib->B2 = be16_to_cpu(buf[B2]);
> +       calib->MB = be16_to_cpu(buf[MB]);
> +       calib->MC = be16_to_cpu(buf[MC]);
> +       calib->MD = be16_to_cpu(buf[MD]);
> +
> +       return 0;
> +}
> +
> +/*
> + * Returns temperature in DegC, resolution is 0.1 DegC.
> + * t_fine carries fine temperature as global value.
> + *
> + * Taken from datasheet, Section 3.5, "Calculating pressure and temperature".
> + */
> +static s32 bmp180_compensate_temp(struct bmp280_data *data, s32 adc_temp)
> +{
> +       int ret;
> +       s32 x1, x2;
> +       struct bmp180_calib calib;
> +
> +       ret = bmp180_read_calib(data, &calib);
> +       if (ret < 0) {
> +               dev_err(&data->client->dev,
> +                       "failed to read calibration coefficients\n");
> +               return ret;
> +       }
> +
> +       x1 = ((adc_temp - calib.AC6) * calib.AC5) >> 15;
> +       x2 = (calib.MC << 11) / (x1 + calib.MD);
> +       data->t_fine = x1 + x2;
> +
> +       return (data->t_fine + 8) >> 4;
> +}
> +
> +static int bmp180_read_temp(struct bmp280_data *data, int *val)
> +{
> +       int ret;
> +       s32 adc_temp, comp_temp;
> +
> +       ret = bmp180_read_adc_temp(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;
> +}
> +
> +static int bmp180_read_adc_press(struct bmp280_data *data, int *val)
> +{
> +       int ret;
> +       __be32 tmp = 0;
> +       u8 oss = ilog2(8);
> +
> +       ret = bmp180_measure(data, BMP180_MEAS_PRESS_X(oss));
> +       if (ret)
> +               return ret;
> +
> +       ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB, (u8 *)&tmp, 3);
> +       if (ret)
> +               return ret;
> +
> +       *val = (be32_to_cpu(tmp) >> 8) >> (8 - oss);
> +
> +       return 0;
> +}
> +
> +/*
> + * Returns pressure in Pa, resolution is 1 Pa.
> + *
> + * Taken from datasheet, Section 3.5, "Calculating pressure and temperature".
> + */
> +static u32 bmp180_compensate_press(struct bmp280_data *data, s32 adc_press)
> +{
> +       int ret;
> +       s32 x1, x2, x3, p;
> +       s32 b3, b6;
> +       u32 b4, b7;
> +       s32 oss = ilog2(8);
> +       struct bmp180_calib calib;
> +
> +       ret = bmp180_read_calib(data, &calib);
> +       if (ret < 0) {
> +               dev_err(&data->client->dev,
> +                       "failed to read calibration coefficients\n");
> +               return ret;
> +       }
> +
> +       b6 = data->t_fine - 4000;
> +       x1 = (calib.B2 * (b6 * b6 >> 12)) >> 11;
> +       x2 = calib.AC2 * b6 >> 11;
> +       x3 = x1 + x2;
> +       b3 = ((((s32)calib.AC1 * 4 + x3) << oss) + 2) / 4;
> +       x1 = calib.AC3 * b6 >> 13;
> +       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);
> +       if (b7 < 0x80000000)
> +               p = (b7 * 2) / b4;
> +       else
> +               p = (b7 / b4) * 2;
> +
> +       x1 = (p >> 8) * (p >> 8);
> +       x1 = (x1 * 3038) >> 16;
> +       x2 = (-7357 * p) >> 16;
> +
> +       return p + ((x1 + x2 + 3791) >> 4);
> +}
> +
> +static int bmp180_read_press(struct bmp280_data *data,
> +                            int *val, int *val2)
> +{
> +       int ret;
> +       s32 adc_press;
> +       u32 comp_press;
> +
> +       /* Read and compensate temperature so we get a reading of t_fine. */
> +       ret = bmp180_read_temp(data, NULL);
> +       if (ret)
> +               return ret;
> +
> +       ret = bmp180_read_adc_press(data, &adc_press);
> +       if (ret)
> +               return ret;
> +
> +       comp_press = bmp180_compensate_press(data, adc_press);
> +
> +       *val = comp_press;
> +       *val2 = 1000;
> +
> +       return IIO_VAL_FRACTIONAL;
> +}
> +
> +static int bmp180_chip_config(struct bmp280_data *data)
> +{
> +       return 0;
> +}
> +
> +static const struct bmp280_chip_info bmp180_chip_info = {
> +       .regmap_config = &bmp180_regmap_config,
> +       .chip_config = bmp180_chip_config,
> +       .read_temp = bmp180_read_temp,
> +       .read_press = bmp180_read_press,
> +};
> +
>  static int bmp280_probe(struct i2c_client *client,
>                         const struct i2c_device_id *id)
>  {
> @@ -367,7 +690,19 @@ static int bmp280_probe(struct i2c_client *client,
>         indio_dev->info = &bmp280_info;
>         indio_dev->modes = INDIO_DIRECT_MODE;
>
> -       data->regmap = devm_regmap_init_i2c(client, &bmp280_regmap_config);
> +       switch (id->driver_data) {
> +       case BMP180_CHIP_ID:
> +               data->chip_info = &bmp180_chip_info;
> +               break;
> +       case BMP280_CHIP_ID:
> +               data->chip_info = &bmp280_chip_info;
> +               break;
> +       default:
> +               return -EINVAL;
> +       }
> +
> +       data->regmap = devm_regmap_init_i2c(client,
> +                                       data->chip_info->regmap_config);
>         if (IS_ERR(data->regmap)) {
>                 dev_err(&client->dev, "failed to allocate register map\n");
>                 return PTR_ERR(data->regmap);
> @@ -376,13 +711,13 @@ static int bmp280_probe(struct i2c_client *client,
>         ret = regmap_read(data->regmap, BMP280_REG_ID, &chip_id);
>         if (ret < 0)
>                 return ret;
> -       if (chip_id != BMP280_CHIP_ID) {
> +       if (chip_id != id->driver_data) {
>                 dev_err(&client->dev, "bad chip id.  expected %x got %x\n",
>                         BMP280_CHIP_ID, chip_id);

BMP280_CHIP_ID should be id->driver_data as well

>                 return -EINVAL;
>         }
>
> -       ret = bmp280_chip_init(data);
> +       ret = data->chip_info->chip_config(data);
>         if (ret < 0)
>                 return ret;
>
> @@ -390,13 +725,17 @@ static int bmp280_probe(struct i2c_client *client,
>  }
>
>  static const struct acpi_device_id bmp280_acpi_match[] = {
> -       {"BMP0280", 0},
> +       {"BMP0280", BMP280_CHIP_ID },
> +       {"BMP0180", BMP180_CHIP_ID },
> +       {"BMP0085", BMP180_CHIP_ID },
>         { },
>  };
>  MODULE_DEVICE_TABLE(acpi, bmp280_acpi_match);
>
>  static const struct i2c_device_id bmp280_id[] = {
> -       {"bmp280", 0},
> +       {"bmp280", BMP280_CHIP_ID },
> +       {"bmp180", BMP180_CHIP_ID },
> +       {"bmp085", BMP180_CHIP_ID },
>         { },
>  };
>  MODULE_DEVICE_TABLE(i2c, bmp280_id);
> @@ -412,5 +751,5 @@ static struct i2c_driver bmp280_driver = {
>  module_i2c_driver(bmp280_driver);
>
>  MODULE_AUTHOR("Vlad Dogaru <vlad.dogaru@intel.com>");
> -MODULE_DESCRIPTION("Driver for Bosch Sensortec BMP280 pressure and temperature sensor");
> +MODULE_DESCRIPTION("Driver for Bosch Sensortec BMP180/BMP280 pressure and temperature sensor");
>  MODULE_LICENSE("GPL v2");
> --
> 2.5.0
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-iio" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH v3 1/2] iio: pressure: bmp280: add support for BMP180

[Akinobu Mita]

2016-04-27 12:21 GMT+09:00 Matt Ranostay <mranostay@gmail.com>:
>> @@ -376,13 +711,13 @@ static int bmp280_probe(struct i2c_client *client,
>>         ret = regmap_read(data->regmap, BMP280_REG_ID, &chip_id);
>>         if (ret < 0)
>>                 return ret;
>> -       if (chip_id != BMP280_CHIP_ID) {
>> +       if (chip_id != id->driver_data) {
>>                 dev_err(&client->dev, "bad chip id.  expected %x got %x\n",
>>                         BMP280_CHIP_ID, chip_id);
>
> BMP280_CHIP_ID should be id->driver_data as well

Good catch!  I'll prepare a fix.

[PATCH v3 2/2] iio: pressure: bmp280: add ability to control oversampling rate

[Akinobu Mita]

This adds ability to control the oversampling ratio of the temperature
and pressure measurement for both bmp180 and bmp280.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Vlad Dogaru <vlad.dogaru@intel.com>
Cc: Christoph Mair <christoph.mair@gmail.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Peter Meerwald <pmeerw@pmeerw.net>
---
* v3
- fix oversampling register setting for bmp280, spotted by Vlad Dogaru

 drivers/iio/pressure/bmp280.c | 203 ++++++++++++++++++++++++++++++++++++++----
 1 file changed, 185 insertions(+), 18 deletions(-)

diff --git a/drivers/iio/pressure/bmp280.c b/drivers/iio/pressure/bmp280.c
index dcf3b0a..2f1498e 100644
--- a/drivers/iio/pressure/bmp280.c
+++ b/drivers/iio/pressure/bmp280.c
@@ -48,19 +48,21 @@
 
 #define BMP280_OSRS_TEMP_MASK		(BIT(7) | BIT(6) | BIT(5))
 #define BMP280_OSRS_TEMP_SKIP		0
-#define BMP280_OSRS_TEMP_1X		BIT(5)
-#define BMP280_OSRS_TEMP_2X		BIT(6)
-#define BMP280_OSRS_TEMP_4X		(BIT(6) | BIT(5))
-#define BMP280_OSRS_TEMP_8X		BIT(7)
-#define BMP280_OSRS_TEMP_16X		(BIT(7) | BIT(5))
+#define BMP280_OSRS_TEMP_X(osrs_t)	((osrs_t) << 5)
+#define BMP280_OSRS_TEMP_1X		BMP280_OSRS_TEMP_X(1)
+#define BMP280_OSRS_TEMP_2X		BMP280_OSRS_TEMP_X(2)
+#define BMP280_OSRS_TEMP_4X		BMP280_OSRS_TEMP_X(3)
+#define BMP280_OSRS_TEMP_8X		BMP280_OSRS_TEMP_X(4)
+#define BMP280_OSRS_TEMP_16X		BMP280_OSRS_TEMP_X(5)
 
 #define BMP280_OSRS_PRESS_MASK		(BIT(4) | BIT(3) | BIT(2))
 #define BMP280_OSRS_PRESS_SKIP		0
-#define BMP280_OSRS_PRESS_1X		BIT(2)
-#define BMP280_OSRS_PRESS_2X		BIT(3)
-#define BMP280_OSRS_PRESS_4X		(BIT(3) | BIT(2))
-#define BMP280_OSRS_PRESS_8X		BIT(4)
-#define BMP280_OSRS_PRESS_16X		(BIT(4) | BIT(2))
+#define BMP280_OSRS_PRESS_X(osrs_p)	((osrs_p) << 2)
+#define BMP280_OSRS_PRESS_1X		BMP280_OSRS_PRESS_X(1)
+#define BMP280_OSRS_PRESS_2X		BMP280_OSRS_PRESS_X(2)
+#define BMP280_OSRS_PRESS_4X		BMP280_OSRS_PRESS_X(3)
+#define BMP280_OSRS_PRESS_8X		BMP280_OSRS_PRESS_X(4)
+#define BMP280_OSRS_PRESS_16X		BMP280_OSRS_PRESS_X(5)
 
 #define BMP280_MODE_MASK		(BIT(1) | BIT(0))
 #define BMP280_MODE_SLEEP		0
@@ -98,6 +100,10 @@ struct bmp280_data {
 	struct regmap *regmap;
 	const struct bmp280_chip_info *chip_info;
 
+	/* log of base 2 of oversampling rate */
+	u8 oversampling_press;
+	u8 oversampling_temp;
+
 	/*
 	 * Carryover value from temperature conversion, used in pressure
 	 * calculation.
@@ -108,6 +114,12 @@ struct bmp280_data {
 struct bmp280_chip_info {
 	const struct regmap_config *regmap_config;
 
+	const int *oversampling_temp_avail;
+	int num_oversampling_temp_avail;
+
+	const int *oversampling_press_avail;
+	int num_oversampling_press_avail;
+
 	int (*chip_config)(struct bmp280_data *);
 	int (*read_temp)(struct bmp280_data *, int *);
 	int (*read_press)(struct bmp280_data *, int *, int *);
@@ -123,11 +135,13 @@ enum { P1, P2, P3, P4, P5, P6, P7, P8, P9 };
 static const struct iio_chan_spec bmp280_channels[] = {
 	{
 		.type = IIO_PRESSURE,
-		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
+				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
 	},
 	{
 		.type = IIO_TEMP,
-		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
+				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
 	},
 };
 
@@ -333,6 +347,21 @@ static int bmp280_read_raw(struct iio_dev *indio_dev,
 			break;
 		}
 		break;
+	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+		switch (chan->type) {
+		case IIO_PRESSURE:
+			*val = 1 << data->oversampling_press;
+			ret = IIO_VAL_INT;
+			break;
+		case IIO_TEMP:
+			*val = 1 << data->oversampling_temp;
+			ret = IIO_VAL_INT;
+			break;
+		default:
+			ret = -EINVAL;
+			break;
+		}
+		break;
 	default:
 		ret = -EINVAL;
 		break;
@@ -343,22 +372,135 @@ static int bmp280_read_raw(struct iio_dev *indio_dev,
 	return ret;
 }
 
+static int bmp280_write_oversampling_ratio_temp(struct bmp280_data *data,
+					       int val)
+{
+	int i;
+	const int *avail = data->chip_info->oversampling_temp_avail;
+	const int n = data->chip_info->num_oversampling_temp_avail;
+
+	for (i = 0; i < n; i++) {
+		if (avail[i] == val) {
+			data->oversampling_temp = ilog2(val);
+
+			return data->chip_info->chip_config(data);
+		}
+	}
+	return -EINVAL;
+}
+
+static int bmp280_write_oversampling_ratio_press(struct bmp280_data *data,
+					       int val)
+{
+	int i;
+	const int *avail = data->chip_info->oversampling_press_avail;
+	const int n = data->chip_info->num_oversampling_press_avail;
+
+	for (i = 0; i < n; i++) {
+		if (avail[i] == val) {
+			data->oversampling_press = ilog2(val);
+
+			return data->chip_info->chip_config(data);
+		}
+	}
+	return -EINVAL;
+}
+
+static int bmp280_write_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan,
+			    int val, int val2, long mask)
+{
+	int ret = 0;
+	struct bmp280_data *data = iio_priv(indio_dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+		mutex_lock(&data->lock);
+		switch (chan->type) {
+		case IIO_PRESSURE:
+			ret = bmp280_write_oversampling_ratio_press(data, val);
+			break;
+		case IIO_TEMP:
+			ret = bmp280_write_oversampling_ratio_temp(data, val);
+			break;
+		default:
+			ret = -EINVAL;
+			break;
+		}
+		mutex_unlock(&data->lock);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return ret;
+}
+
+static ssize_t bmp280_show_avail(char *buf, const int *vals, const int n)
+{
+	size_t len = 0;
+	int i;
+
+	for (i = 0; i < n; i++)
+		len += scnprintf(buf + len, PAGE_SIZE - len, "%d ", vals[i]);
+
+	buf[len - 1] = '\n';
+
+	return len;
+}
+
+static ssize_t bmp280_show_temp_oversampling_avail(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct bmp280_data *data = iio_priv(dev_to_iio_dev(dev));
+
+	return bmp280_show_avail(buf, data->chip_info->oversampling_temp_avail,
+				 data->chip_info->num_oversampling_temp_avail);
+}
+
+static ssize_t bmp280_show_press_oversampling_avail(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct bmp280_data *data = iio_priv(dev_to_iio_dev(dev));
+
+	return bmp280_show_avail(buf, data->chip_info->oversampling_press_avail,
+				 data->chip_info->num_oversampling_press_avail);
+}
+
+static IIO_DEVICE_ATTR(in_temp_oversampling_ratio_available,
+	S_IRUGO, bmp280_show_temp_oversampling_avail, NULL, 0);
+
+static IIO_DEVICE_ATTR(in_pressure_oversampling_ratio_available,
+	S_IRUGO, bmp280_show_press_oversampling_avail, NULL, 0);
+
+static struct attribute *bmp280_attributes[] = {
+	&iio_dev_attr_in_temp_oversampling_ratio_available.dev_attr.attr,
+	&iio_dev_attr_in_pressure_oversampling_ratio_available.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group bmp280_attrs_group = {
+	.attrs = bmp280_attributes,
+};
+
 static const struct iio_info bmp280_info = {
 	.driver_module = THIS_MODULE,
 	.read_raw = &bmp280_read_raw,
+	.write_raw = &bmp280_write_raw,
+	.attrs = &bmp280_attrs_group,
 };
 
 static int bmp280_chip_config(struct bmp280_data *data)
 {
 	int ret;
+	u8 osrs = BMP280_OSRS_TEMP_X(data->oversampling_temp + 1) |
+		  BMP280_OSRS_PRESS_X(data->oversampling_press + 1);
 
 	ret = regmap_update_bits(data->regmap, BMP280_REG_CTRL_MEAS,
 				 BMP280_OSRS_TEMP_MASK |
 				 BMP280_OSRS_PRESS_MASK |
 				 BMP280_MODE_MASK,
-				 BMP280_OSRS_TEMP_2X |
-				 BMP280_OSRS_PRESS_16X |
-				 BMP280_MODE_NORMAL);
+				 osrs | BMP280_MODE_NORMAL);
 	if (ret < 0) {
 		dev_err(&data->client->dev,
 			"failed to write ctrl_meas register\n");
@@ -377,8 +519,17 @@ static int bmp280_chip_config(struct bmp280_data *data)
 	return ret;
 }
 
+static const int bmp280_oversampling_avail[] = { 1, 2, 4, 8, 16 };
+
 static const struct bmp280_chip_info bmp280_chip_info = {
 	.regmap_config = &bmp280_regmap_config,
+
+	.oversampling_temp_avail = bmp280_oversampling_avail,
+	.num_oversampling_temp_avail = ARRAY_SIZE(bmp280_oversampling_avail),
+
+	.oversampling_press_avail = bmp280_oversampling_avail,
+	.num_oversampling_press_avail = ARRAY_SIZE(bmp280_oversampling_avail),
+
 	.chip_config = bmp280_chip_config,
 	.read_temp = bmp280_read_temp,
 	.read_press = bmp280_read_press,
@@ -433,7 +584,7 @@ static int bmp180_measure(struct bmp280_data *data, u8 ctrl_meas)
 	if (ctrl_meas == BMP180_MEAS_TEMP)
 		delay_us = 4500;
 	else
-		delay_us = conversion_time_max[ilog2(8)];
+		delay_us = conversion_time_max[data->oversampling_press];
 
 	usleep_range(delay_us, delay_us + 1000);
 
@@ -573,7 +724,7 @@ static int bmp180_read_adc_press(struct bmp280_data *data, int *val)
 {
 	int ret;
 	__be32 tmp = 0;
-	u8 oss = ilog2(8);
+	u8 oss = data->oversampling_press;
 
 	ret = bmp180_measure(data, BMP180_MEAS_PRESS_X(oss));
 	if (ret)
@@ -599,7 +750,7 @@ static u32 bmp180_compensate_press(struct bmp280_data *data, s32 adc_press)
 	s32 x1, x2, x3, p;
 	s32 b3, b6;
 	u32 b4, b7;
-	s32 oss = ilog2(8);
+	s32 oss = data->oversampling_press;
 	struct bmp180_calib calib;
 
 	ret = bmp180_read_calib(data, &calib);
@@ -660,8 +811,20 @@ static int bmp180_chip_config(struct bmp280_data *data)
 	return 0;
 }
 
+static const int bmp180_oversampling_temp_avail[] = { 1 };
+static const int bmp180_oversampling_press_avail[] = { 1, 2, 4, 8 };
+
 static const struct bmp280_chip_info bmp180_chip_info = {
 	.regmap_config = &bmp180_regmap_config,
+
+	.oversampling_temp_avail = bmp180_oversampling_temp_avail,
+	.num_oversampling_temp_avail =
+		ARRAY_SIZE(bmp180_oversampling_temp_avail),
+
+	.oversampling_press_avail = bmp180_oversampling_press_avail,
+	.num_oversampling_press_avail =
+		ARRAY_SIZE(bmp180_oversampling_press_avail),
+
 	.chip_config = bmp180_chip_config,
 	.read_temp = bmp180_read_temp,
 	.read_press = bmp180_read_press,
@@ -693,9 +856,13 @@ static int bmp280_probe(struct i2c_client *client,
 	switch (id->driver_data) {
 	case BMP180_CHIP_ID:
 		data->chip_info = &bmp180_chip_info;
+		data->oversampling_press = ilog2(8);
+		data->oversampling_temp = ilog2(1);
 		break;
 	case BMP280_CHIP_ID:
 		data->chip_info = &bmp280_chip_info;
+		data->oversampling_press = ilog2(16);
+		data->oversampling_temp = ilog2(2);
 		break;
 	default:
 		return -EINVAL;
-- 
2.5.0

Re: [PATCH v3 2/2] iio: pressure: bmp280: add ability to control oversampling rate

[Matt Ranostay]

On Sun, Apr 24, 2016 at 6:52 AM, Akinobu Mita <akinobu.mita@gmail.com> wrote:
> This adds ability to control the oversampling ratio of the temperature
> and pressure measurement for both bmp180 and bmp280.
>
> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
> Cc: Vlad Dogaru <vlad.dogaru@intel.com>
> Cc: Christoph Mair <christoph.mair@gmail.com>
> Cc: Jonathan Cameron <jic23@kernel.org>
> Cc: Hartmut Knaack <knaack.h@gmx.de>
> Cc: Lars-Peter Clausen <lars@metafoo.de>
> Cc: Peter Meerwald <pmeerw@pmeerw.net>
> ---
> * v3
> - fix oversampling register setting for bmp280, spotted by Vlad Dogaru
>
>  drivers/iio/pressure/bmp280.c | 203 ++++++++++++++++++++++++++++++++++++++----
>  1 file changed, 185 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/iio/pressure/bmp280.c b/drivers/iio/pressure/bmp280.c
> index dcf3b0a..2f1498e 100644
> --- a/drivers/iio/pressure/bmp280.c
> +++ b/drivers/iio/pressure/bmp280.c
> @@ -48,19 +48,21 @@
>
>  #define BMP280_OSRS_TEMP_MASK          (BIT(7) | BIT(6) | BIT(5))
>  #define BMP280_OSRS_TEMP_SKIP          0
> -#define BMP280_OSRS_TEMP_1X            BIT(5)
> -#define BMP280_OSRS_TEMP_2X            BIT(6)
> -#define BMP280_OSRS_TEMP_4X            (BIT(6) | BIT(5))
> -#define BMP280_OSRS_TEMP_8X            BIT(7)
> -#define BMP280_OSRS_TEMP_16X           (BIT(7) | BIT(5))
> +#define BMP280_OSRS_TEMP_X(osrs_t)     ((osrs_t) << 5)
> +#define BMP280_OSRS_TEMP_1X            BMP280_OSRS_TEMP_X(1)
> +#define BMP280_OSRS_TEMP_2X            BMP280_OSRS_TEMP_X(2)
> +#define BMP280_OSRS_TEMP_4X            BMP280_OSRS_TEMP_X(3)
> +#define BMP280_OSRS_TEMP_8X            BMP280_OSRS_TEMP_X(4)
> +#define BMP280_OSRS_TEMP_16X           BMP280_OSRS_TEMP_X(5)
>
>  #define BMP280_OSRS_PRESS_MASK         (BIT(4) | BIT(3) | BIT(2))
>  #define BMP280_OSRS_PRESS_SKIP         0
> -#define BMP280_OSRS_PRESS_1X           BIT(2)
> -#define BMP280_OSRS_PRESS_2X           BIT(3)
> -#define BMP280_OSRS_PRESS_4X           (BIT(3) | BIT(2))
> -#define BMP280_OSRS_PRESS_8X           BIT(4)
> -#define BMP280_OSRS_PRESS_16X          (BIT(4) | BIT(2))
> +#define BMP280_OSRS_PRESS_X(osrs_p)    ((osrs_p) << 2)
> +#define BMP280_OSRS_PRESS_1X           BMP280_OSRS_PRESS_X(1)
> +#define BMP280_OSRS_PRESS_2X           BMP280_OSRS_PRESS_X(2)
> +#define BMP280_OSRS_PRESS_4X           BMP280_OSRS_PRESS_X(3)
> +#define BMP280_OSRS_PRESS_8X           BMP280_OSRS_PRESS_X(4)
> +#define BMP280_OSRS_PRESS_16X          BMP280_OSRS_PRESS_X(5)
>
>  #define BMP280_MODE_MASK               (BIT(1) | BIT(0))
>  #define BMP280_MODE_SLEEP              0
> @@ -98,6 +100,10 @@ struct bmp280_data {
>         struct regmap *regmap;
>         const struct bmp280_chip_info *chip_info;
>
> +       /* log of base 2 of oversampling rate */
> +       u8 oversampling_press;
> +       u8 oversampling_temp;
> +
>         /*
>          * Carryover value from temperature conversion, used in pressure
>          * calculation.
> @@ -108,6 +114,12 @@ struct bmp280_data {
>  struct bmp280_chip_info {
>         const struct regmap_config *regmap_config;
>
> +       const int *oversampling_temp_avail;
> +       int num_oversampling_temp_avail;
> +
> +       const int *oversampling_press_avail;
> +       int num_oversampling_press_avail;

You declare oversampling_press_avail and num_ oversampling_press_avail twice!

> +
>         int (*chip_config)(struct bmp280_data *);
>         int (*read_temp)(struct bmp280_data *, int *);
>         int (*read_press)(struct bmp280_data *, int *, int *);
> @@ -123,11 +135,13 @@ enum { P1, P2, P3, P4, P5, P6, P7, P8, P9 };
>  static const struct iio_chan_spec bmp280_channels[] = {
>         {
>                 .type = IIO_PRESSURE,
> -               .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
> +               .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
> +                                     BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
>         },
>         {
>                 .type = IIO_TEMP,
> -               .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
> +               .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
> +                                     BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
>         },
>  };
>
> @@ -333,6 +347,21 @@ static int bmp280_read_raw(struct iio_dev *indio_dev,
>                         break;
>                 }
>                 break;
> +       case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
> +               switch (chan->type) {
> +               case IIO_PRESSURE:
> +                       *val = 1 << data->oversampling_press;
> +                       ret = IIO_VAL_INT;
> +                       break;
> +               case IIO_TEMP:
> +                       *val = 1 << data->oversampling_temp;
> +                       ret = IIO_VAL_INT;
> +                       break;
> +               default:
> +                       ret = -EINVAL;
> +                       break;
> +               }
> +               break;
>         default:
>                 ret = -EINVAL;
>                 break;
> @@ -343,22 +372,135 @@ static int bmp280_read_raw(struct iio_dev *indio_dev,
>         return ret;
>  }
>
> +static int bmp280_write_oversampling_ratio_temp(struct bmp280_data *data,
> +                                              int val)
> +{
> +       int i;
> +       const int *avail = data->chip_info->oversampling_temp_avail;
> +       const int n = data->chip_info->num_oversampling_temp_avail;
> +
> +       for (i = 0; i < n; i++) {
> +               if (avail[i] == val) {
> +                       data->oversampling_temp = ilog2(val);
> +
> +                       return data->chip_info->chip_config(data);
> +               }
> +       }
> +       return -EINVAL;
> +}
> +
> +static int bmp280_write_oversampling_ratio_press(struct bmp280_data *data,
> +                                              int val)
> +{
> +       int i;
> +       const int *avail = data->chip_info->oversampling_press_avail;
> +       const int n = data->chip_info->num_oversampling_press_avail;
> +
> +       for (i = 0; i < n; i++) {
> +               if (avail[i] == val) {
> +                       data->oversampling_press = ilog2(val);
> +
> +                       return data->chip_info->chip_config(data);
> +               }
> +       }
> +       return -EINVAL;
> +}
> +
> +static int bmp280_write_raw(struct iio_dev *indio_dev,
> +                           struct iio_chan_spec const *chan,
> +                           int val, int val2, long mask)
> +{
> +       int ret = 0;
> +       struct bmp280_data *data = iio_priv(indio_dev);
> +
> +       switch (mask) {
> +       case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
> +               mutex_lock(&data->lock);
> +               switch (chan->type) {
> +               case IIO_PRESSURE:
> +                       ret = bmp280_write_oversampling_ratio_press(data, val);
> +                       break;
> +               case IIO_TEMP:
> +                       ret = bmp280_write_oversampling_ratio_temp(data, val);
> +                       break;
> +               default:
> +                       ret = -EINVAL;
> +                       break;
> +               }
> +               mutex_unlock(&data->lock);
> +               break;
> +       default:
> +               return -EINVAL;
> +       }
> +
> +       return ret;
> +}
> +
> +static ssize_t bmp280_show_avail(char *buf, const int *vals, const int n)
> +{
> +       size_t len = 0;
> +       int i;
> +
> +       for (i = 0; i < n; i++)
> +               len += scnprintf(buf + len, PAGE_SIZE - len, "%d ", vals[i]);
> +
> +       buf[len - 1] = '\n';
> +
> +       return len;
> +}
> +
> +static ssize_t bmp280_show_temp_oversampling_avail(struct device *dev,
> +                               struct device_attribute *attr, char *buf)
> +{
> +       struct bmp280_data *data = iio_priv(dev_to_iio_dev(dev));
> +
> +       return bmp280_show_avail(buf, data->chip_info->oversampling_temp_avail,
> +                                data->chip_info->num_oversampling_temp_avail);
> +}
> +
> +static ssize_t bmp280_show_press_oversampling_avail(struct device *dev,
> +                               struct device_attribute *attr, char *buf)
> +{
> +       struct bmp280_data *data = iio_priv(dev_to_iio_dev(dev));
> +
> +       return bmp280_show_avail(buf, data->chip_info->oversampling_press_avail,
> +                                data->chip_info->num_oversampling_press_avail);
> +}
> +
> +static IIO_DEVICE_ATTR(in_temp_oversampling_ratio_available,
> +       S_IRUGO, bmp280_show_temp_oversampling_avail, NULL, 0);
> +
> +static IIO_DEVICE_ATTR(in_pressure_oversampling_ratio_available,
> +       S_IRUGO, bmp280_show_press_oversampling_avail, NULL, 0);
> +
> +static struct attribute *bmp280_attributes[] = {
> +       &iio_dev_attr_in_temp_oversampling_ratio_available.dev_attr.attr,
> +       &iio_dev_attr_in_pressure_oversampling_ratio_available.dev_attr.attr,
> +       NULL,
> +};
> +
> +static const struct attribute_group bmp280_attrs_group = {
> +       .attrs = bmp280_attributes,
> +};
> +
>  static const struct iio_info bmp280_info = {
>         .driver_module = THIS_MODULE,
>         .read_raw = &bmp280_read_raw,
> +       .write_raw = &bmp280_write_raw,
> +       .attrs = &bmp280_attrs_group,
>  };
>
>  static int bmp280_chip_config(struct bmp280_data *data)
>  {
>         int ret;
> +       u8 osrs = BMP280_OSRS_TEMP_X(data->oversampling_temp + 1) |
> +                 BMP280_OSRS_PRESS_X(data->oversampling_press + 1);
>
>         ret = regmap_update_bits(data->regmap, BMP280_REG_CTRL_MEAS,
>                                  BMP280_OSRS_TEMP_MASK |
>                                  BMP280_OSRS_PRESS_MASK |
>                                  BMP280_MODE_MASK,
> -                                BMP280_OSRS_TEMP_2X |
> -                                BMP280_OSRS_PRESS_16X |
> -                                BMP280_MODE_NORMAL);
> +                                osrs | BMP280_MODE_NORMAL);
>         if (ret < 0) {
>                 dev_err(&data->client->dev,
>                         "failed to write ctrl_meas register\n");
> @@ -377,8 +519,17 @@ static int bmp280_chip_config(struct bmp280_data *data)
>         return ret;
>  }
>
> +static const int bmp280_oversampling_avail[] = { 1, 2, 4, 8, 16 };
> +
>  static const struct bmp280_chip_info bmp280_chip_info = {
>         .regmap_config = &bmp280_regmap_config,
> +
> +       .oversampling_temp_avail = bmp280_oversampling_avail,
> +       .num_oversampling_temp_avail = ARRAY_SIZE(bmp280_oversampling_avail),
> +
> +       .oversampling_press_avail = bmp280_oversampling_avail,
> +       .num_oversampling_press_avail = ARRAY_SIZE(bmp280_oversampling_avail),
> +
>         .chip_config = bmp280_chip_config,
>         .read_temp = bmp280_read_temp,
>         .read_press = bmp280_read_press,
> @@ -433,7 +584,7 @@ static int bmp180_measure(struct bmp280_data *data, u8 ctrl_meas)
>         if (ctrl_meas == BMP180_MEAS_TEMP)
>                 delay_us = 4500;
>         else
> -               delay_us = conversion_time_max[ilog2(8)];
> +               delay_us = conversion_time_max[data->oversampling_press];
>
>         usleep_range(delay_us, delay_us + 1000);
>
> @@ -573,7 +724,7 @@ static int bmp180_read_adc_press(struct bmp280_data *data, int *val)
>  {
>         int ret;
>         __be32 tmp = 0;
> -       u8 oss = ilog2(8);
> +       u8 oss = data->oversampling_press;
>
>         ret = bmp180_measure(data, BMP180_MEAS_PRESS_X(oss));
>         if (ret)
> @@ -599,7 +750,7 @@ static u32 bmp180_compensate_press(struct bmp280_data *data, s32 adc_press)
>         s32 x1, x2, x3, p;
>         s32 b3, b6;
>         u32 b4, b7;
> -       s32 oss = ilog2(8);
> +       s32 oss = data->oversampling_press;
>         struct bmp180_calib calib;
>
>         ret = bmp180_read_calib(data, &calib);
> @@ -660,8 +811,20 @@ static int bmp180_chip_config(struct bmp280_data *data)
>         return 0;
>  }
>
> +static const int bmp180_oversampling_temp_avail[] = { 1 };
> +static const int bmp180_oversampling_press_avail[] = { 1, 2, 4, 8 };
> +
>  static const struct bmp280_chip_info bmp180_chip_info = {
>         .regmap_config = &bmp180_regmap_config,
> +
> +       .oversampling_temp_avail = bmp180_oversampling_temp_avail,
> +       .num_oversampling_temp_avail =
> +               ARRAY_SIZE(bmp180_oversampling_temp_avail),
> +
> +       .oversampling_press_avail = bmp180_oversampling_press_avail,
> +       .num_oversampling_press_avail =
> +               ARRAY_SIZE(bmp180_oversampling_press_avail),
> +
>         .chip_config = bmp180_chip_config,
>         .read_temp = bmp180_read_temp,
>         .read_press = bmp180_read_press,
> @@ -693,9 +856,13 @@ static int bmp280_probe(struct i2c_client *client,
>         switch (id->driver_data) {
>         case BMP180_CHIP_ID:
>                 data->chip_info = &bmp180_chip_info;
> +               data->oversampling_press = ilog2(8);
> +               data->oversampling_temp = ilog2(1);
>                 break;
>         case BMP280_CHIP_ID:
>                 data->chip_info = &bmp280_chip_info;
> +               data->oversampling_press = ilog2(16);
> +               data->oversampling_temp = ilog2(2);
>                 break;
>         default:
>                 return -EINVAL;
> --
> 2.5.0
>
> --
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> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH v3 2/2] iio: pressure: bmp280: add ability to control oversampling rate

[Matt Ranostay]

Ah nm misread that :)

On Sun, Apr 24, 2016 at 2:38 PM, Matt Ranostay <mranostay@gmail.com> wrote:
> On Sun, Apr 24, 2016 at 6:52 AM, Akinobu Mita <akinobu.mita@gmail.com> wrote:
>> This adds ability to control the oversampling ratio of the temperature
>> and pressure measurement for both bmp180 and bmp280.
>>
>> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
>> Cc: Vlad Dogaru <vlad.dogaru@intel.com>
>> Cc: Christoph Mair <christoph.mair@gmail.com>
>> Cc: Jonathan Cameron <jic23@kernel.org>
>> Cc: Hartmut Knaack <knaack.h@gmx.de>
>> Cc: Lars-Peter Clausen <lars@metafoo.de>
>> Cc: Peter Meerwald <pmeerw@pmeerw.net>
>> ---
>> * v3
>> - fix oversampling register setting for bmp280, spotted by Vlad Dogaru
>>
>>  drivers/iio/pressure/bmp280.c | 203 ++++++++++++++++++++++++++++++++++++++----
>>  1 file changed, 185 insertions(+), 18 deletions(-)
>>
>> diff --git a/drivers/iio/pressure/bmp280.c b/drivers/iio/pressure/bmp280.c
>> index dcf3b0a..2f1498e 100644
>> --- a/drivers/iio/pressure/bmp280.c
>> +++ b/drivers/iio/pressure/bmp280.c
>> @@ -48,19 +48,21 @@
>>
>>  #define BMP280_OSRS_TEMP_MASK          (BIT(7) | BIT(6) | BIT(5))
>>  #define BMP280_OSRS_TEMP_SKIP          0
>> -#define BMP280_OSRS_TEMP_1X            BIT(5)
>> -#define BMP280_OSRS_TEMP_2X            BIT(6)
>> -#define BMP280_OSRS_TEMP_4X            (BIT(6) | BIT(5))
>> -#define BMP280_OSRS_TEMP_8X            BIT(7)
>> -#define BMP280_OSRS_TEMP_16X           (BIT(7) | BIT(5))
>> +#define BMP280_OSRS_TEMP_X(osrs_t)     ((osrs_t) << 5)
>> +#define BMP280_OSRS_TEMP_1X            BMP280_OSRS_TEMP_X(1)
>> +#define BMP280_OSRS_TEMP_2X            BMP280_OSRS_TEMP_X(2)
>> +#define BMP280_OSRS_TEMP_4X            BMP280_OSRS_TEMP_X(3)
>> +#define BMP280_OSRS_TEMP_8X            BMP280_OSRS_TEMP_X(4)
>> +#define BMP280_OSRS_TEMP_16X           BMP280_OSRS_TEMP_X(5)
>>
>>  #define BMP280_OSRS_PRESS_MASK         (BIT(4) | BIT(3) | BIT(2))
>>  #define BMP280_OSRS_PRESS_SKIP         0
>> -#define BMP280_OSRS_PRESS_1X           BIT(2)
>> -#define BMP280_OSRS_PRESS_2X           BIT(3)
>> -#define BMP280_OSRS_PRESS_4X           (BIT(3) | BIT(2))
>> -#define BMP280_OSRS_PRESS_8X           BIT(4)
>> -#define BMP280_OSRS_PRESS_16X          (BIT(4) | BIT(2))
>> +#define BMP280_OSRS_PRESS_X(osrs_p)    ((osrs_p) << 2)
>> +#define BMP280_OSRS_PRESS_1X           BMP280_OSRS_PRESS_X(1)
>> +#define BMP280_OSRS_PRESS_2X           BMP280_OSRS_PRESS_X(2)
>> +#define BMP280_OSRS_PRESS_4X           BMP280_OSRS_PRESS_X(3)
>> +#define BMP280_OSRS_PRESS_8X           BMP280_OSRS_PRESS_X(4)
>> +#define BMP280_OSRS_PRESS_16X          BMP280_OSRS_PRESS_X(5)
>>
>>  #define BMP280_MODE_MASK               (BIT(1) | BIT(0))
>>  #define BMP280_MODE_SLEEP              0
>> @@ -98,6 +100,10 @@ struct bmp280_data {
>>         struct regmap *regmap;
>>         const struct bmp280_chip_info *chip_info;
>>
>> +       /* log of base 2 of oversampling rate */
>> +       u8 oversampling_press;
>> +       u8 oversampling_temp;
>> +
>>         /*
>>          * Carryover value from temperature conversion, used in pressure
>>          * calculation.
>> @@ -108,6 +114,12 @@ struct bmp280_data {
>>  struct bmp280_chip_info {
>>         const struct regmap_config *regmap_config;
>>
>> +       const int *oversampling_temp_avail;
>> +       int num_oversampling_temp_avail;
>> +
>> +       const int *oversampling_press_avail;
>> +       int num_oversampling_press_avail;
>
> You declare oversampling_press_avail and num_ oversampling_press_avail twice!
>
>> +
>>         int (*chip_config)(struct bmp280_data *);
>>         int (*read_temp)(struct bmp280_data *, int *);
>>         int (*read_press)(struct bmp280_data *, int *, int *);
>> @@ -123,11 +135,13 @@ enum { P1, P2, P3, P4, P5, P6, P7, P8, P9 };
>>  static const struct iio_chan_spec bmp280_channels[] = {
>>         {
>>                 .type = IIO_PRESSURE,
>> -               .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
>> +               .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
>> +                                     BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
>>         },
>>         {
>>                 .type = IIO_TEMP,
>> -               .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
>> +               .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
>> +                                     BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
>>         },
>>  };
>>
>> @@ -333,6 +347,21 @@ static int bmp280_read_raw(struct iio_dev *indio_dev,
>>                         break;
>>                 }
>>                 break;
>> +       case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
>> +               switch (chan->type) {
>> +               case IIO_PRESSURE:
>> +                       *val = 1 << data->oversampling_press;
>> +                       ret = IIO_VAL_INT;
>> +                       break;
>> +               case IIO_TEMP:
>> +                       *val = 1 << data->oversampling_temp;
>> +                       ret = IIO_VAL_INT;
>> +                       break;
>> +               default:
>> +                       ret = -EINVAL;
>> +                       break;
>> +               }
>> +               break;
>>         default:
>>                 ret = -EINVAL;
>>                 break;
>> @@ -343,22 +372,135 @@ static int bmp280_read_raw(struct iio_dev *indio_dev,
>>         return ret;
>>  }
>>
>> +static int bmp280_write_oversampling_ratio_temp(struct bmp280_data *data,
>> +                                              int val)
>> +{
>> +       int i;
>> +       const int *avail = data->chip_info->oversampling_temp_avail;
>> +       const int n = data->chip_info->num_oversampling_temp_avail;
>> +
>> +       for (i = 0; i < n; i++) {
>> +               if (avail[i] == val) {
>> +                       data->oversampling_temp = ilog2(val);
>> +
>> +                       return data->chip_info->chip_config(data);
>> +               }
>> +       }
>> +       return -EINVAL;
>> +}
>> +
>> +static int bmp280_write_oversampling_ratio_press(struct bmp280_data *data,
>> +                                              int val)
>> +{
>> +       int i;
>> +       const int *avail = data->chip_info->oversampling_press_avail;
>> +       const int n = data->chip_info->num_oversampling_press_avail;
>> +
>> +       for (i = 0; i < n; i++) {
>> +               if (avail[i] == val) {
>> +                       data->oversampling_press = ilog2(val);
>> +
>> +                       return data->chip_info->chip_config(data);
>> +               }
>> +       }
>> +       return -EINVAL;
>> +}
>> +
>> +static int bmp280_write_raw(struct iio_dev *indio_dev,
>> +                           struct iio_chan_spec const *chan,
>> +                           int val, int val2, long mask)
>> +{
>> +       int ret = 0;
>> +       struct bmp280_data *data = iio_priv(indio_dev);
>> +
>> +       switch (mask) {
>> +       case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
>> +               mutex_lock(&data->lock);
>> +               switch (chan->type) {
>> +               case IIO_PRESSURE:
>> +                       ret = bmp280_write_oversampling_ratio_press(data, val);
>> +                       break;
>> +               case IIO_TEMP:
>> +                       ret = bmp280_write_oversampling_ratio_temp(data, val);
>> +                       break;
>> +               default:
>> +                       ret = -EINVAL;
>> +                       break;
>> +               }
>> +               mutex_unlock(&data->lock);
>> +               break;
>> +       default:
>> +               return -EINVAL;
>> +       }
>> +
>> +       return ret;
>> +}
>> +
>> +static ssize_t bmp280_show_avail(char *buf, const int *vals, const int n)
>> +{
>> +       size_t len = 0;
>> +       int i;
>> +
>> +       for (i = 0; i < n; i++)
>> +               len += scnprintf(buf + len, PAGE_SIZE - len, "%d ", vals[i]);
>> +
>> +       buf[len - 1] = '\n';
>> +
>> +       return len;
>> +}
>> +
>> +static ssize_t bmp280_show_temp_oversampling_avail(struct device *dev,
>> +                               struct device_attribute *attr, char *buf)
>> +{
>> +       struct bmp280_data *data = iio_priv(dev_to_iio_dev(dev));
>> +
>> +       return bmp280_show_avail(buf, data->chip_info->oversampling_temp_avail,
>> +                                data->chip_info->num_oversampling_temp_avail);
>> +}
>> +
>> +static ssize_t bmp280_show_press_oversampling_avail(struct device *dev,
>> +                               struct device_attribute *attr, char *buf)
>> +{
>> +       struct bmp280_data *data = iio_priv(dev_to_iio_dev(dev));
>> +
>> +       return bmp280_show_avail(buf, data->chip_info->oversampling_press_avail,
>> +                                data->chip_info->num_oversampling_press_avail);
>> +}
>> +
>> +static IIO_DEVICE_ATTR(in_temp_oversampling_ratio_available,
>> +       S_IRUGO, bmp280_show_temp_oversampling_avail, NULL, 0);
>> +
>> +static IIO_DEVICE_ATTR(in_pressure_oversampling_ratio_available,
>> +       S_IRUGO, bmp280_show_press_oversampling_avail, NULL, 0);
>> +
>> +static struct attribute *bmp280_attributes[] = {
>> +       &iio_dev_attr_in_temp_oversampling_ratio_available.dev_attr.attr,
>> +       &iio_dev_attr_in_pressure_oversampling_ratio_available.dev_attr.attr,
>> +       NULL,
>> +};
>> +
>> +static const struct attribute_group bmp280_attrs_group = {
>> +       .attrs = bmp280_attributes,
>> +};
>> +
>>  static const struct iio_info bmp280_info = {
>>         .driver_module = THIS_MODULE,
>>         .read_raw = &bmp280_read_raw,
>> +       .write_raw = &bmp280_write_raw,
>> +       .attrs = &bmp280_attrs_group,
>>  };
>>
>>  static int bmp280_chip_config(struct bmp280_data *data)
>>  {
>>         int ret;
>> +       u8 osrs = BMP280_OSRS_TEMP_X(data->oversampling_temp + 1) |
>> +                 BMP280_OSRS_PRESS_X(data->oversampling_press + 1);
>>
>>         ret = regmap_update_bits(data->regmap, BMP280_REG_CTRL_MEAS,
>>                                  BMP280_OSRS_TEMP_MASK |
>>                                  BMP280_OSRS_PRESS_MASK |
>>                                  BMP280_MODE_MASK,
>> -                                BMP280_OSRS_TEMP_2X |
>> -                                BMP280_OSRS_PRESS_16X |
>> -                                BMP280_MODE_NORMAL);
>> +                                osrs | BMP280_MODE_NORMAL);
>>         if (ret < 0) {
>>                 dev_err(&data->client->dev,
>>                         "failed to write ctrl_meas register\n");
>> @@ -377,8 +519,17 @@ static int bmp280_chip_config(struct bmp280_data *data)
>>         return ret;
>>  }
>>
>> +static const int bmp280_oversampling_avail[] = { 1, 2, 4, 8, 16 };
>> +
>>  static const struct bmp280_chip_info bmp280_chip_info = {
>>         .regmap_config = &bmp280_regmap_config,
>> +
>> +       .oversampling_temp_avail = bmp280_oversampling_avail,
>> +       .num_oversampling_temp_avail = ARRAY_SIZE(bmp280_oversampling_avail),
>> +
>> +       .oversampling_press_avail = bmp280_oversampling_avail,
>> +       .num_oversampling_press_avail = ARRAY_SIZE(bmp280_oversampling_avail),
>> +
>>         .chip_config = bmp280_chip_config,
>>         .read_temp = bmp280_read_temp,
>>         .read_press = bmp280_read_press,
>> @@ -433,7 +584,7 @@ static int bmp180_measure(struct bmp280_data *data, u8 ctrl_meas)
>>         if (ctrl_meas == BMP180_MEAS_TEMP)
>>                 delay_us = 4500;
>>         else
>> -               delay_us = conversion_time_max[ilog2(8)];
>> +               delay_us = conversion_time_max[data->oversampling_press];
>>
>>         usleep_range(delay_us, delay_us + 1000);
>>
>> @@ -573,7 +724,7 @@ static int bmp180_read_adc_press(struct bmp280_data *data, int *val)
>>  {
>>         int ret;
>>         __be32 tmp = 0;
>> -       u8 oss = ilog2(8);
>> +       u8 oss = data->oversampling_press;
>>
>>         ret = bmp180_measure(data, BMP180_MEAS_PRESS_X(oss));
>>         if (ret)
>> @@ -599,7 +750,7 @@ static u32 bmp180_compensate_press(struct bmp280_data *data, s32 adc_press)
>>         s32 x1, x2, x3, p;
>>         s32 b3, b6;
>>         u32 b4, b7;
>> -       s32 oss = ilog2(8);
>> +       s32 oss = data->oversampling_press;
>>         struct bmp180_calib calib;
>>
>>         ret = bmp180_read_calib(data, &calib);
>> @@ -660,8 +811,20 @@ static int bmp180_chip_config(struct bmp280_data *data)
>>         return 0;
>>  }
>>
>> +static const int bmp180_oversampling_temp_avail[] = { 1 };
>> +static const int bmp180_oversampling_press_avail[] = { 1, 2, 4, 8 };
>> +
>>  static const struct bmp280_chip_info bmp180_chip_info = {
>>         .regmap_config = &bmp180_regmap_config,
>> +
>> +       .oversampling_temp_avail = bmp180_oversampling_temp_avail,
>> +       .num_oversampling_temp_avail =
>> +               ARRAY_SIZE(bmp180_oversampling_temp_avail),
>> +
>> +       .oversampling_press_avail = bmp180_oversampling_press_avail,
>> +       .num_oversampling_press_avail =
>> +               ARRAY_SIZE(bmp180_oversampling_press_avail),
>> +
>>         .chip_config = bmp180_chip_config,
>>         .read_temp = bmp180_read_temp,
>>         .read_press = bmp180_read_press,
>> @@ -693,9 +856,13 @@ static int bmp280_probe(struct i2c_client *client,
>>         switch (id->driver_data) {
>>         case BMP180_CHIP_ID:
>>                 data->chip_info = &bmp180_chip_info;
>> +               data->oversampling_press = ilog2(8);
>> +               data->oversampling_temp = ilog2(1);
>>                 break;
>>         case BMP280_CHIP_ID:
>>                 data->chip_info = &bmp280_chip_info;
>> +               data->oversampling_press = ilog2(16);
>> +               data->oversampling_temp = ilog2(2);
>>                 break;
>>         default:
>>                 return -EINVAL;
>> --
>> 2.5.0
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-iio" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH v3 2/2] iio: pressure: bmp280: add ability to control oversampling rate

[Vlad Dogaru]

On Sun, Apr 24, 2016 at 10:52:11PM +0900, Akinobu Mita wrote:
> This adds ability to control the oversampling ratio of the temperature
> and pressure measurement for both bmp180 and bmp280.
> 
> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
> Cc: Vlad Dogaru <vlad.dogaru@intel.com>
> Cc: Christoph Mair <christoph.mair@gmail.com>
> Cc: Jonathan Cameron <jic23@kernel.org>
> Cc: Hartmut Knaack <knaack.h@gmx.de>
> Cc: Lars-Peter Clausen <lars@metafoo.de>
> Cc: Peter Meerwald <pmeerw@pmeerw.net>

Acked-by: Vlad Dogaru <vlad.dogaru@intel.com>

> ---
> * v3
> - fix oversampling register setting for bmp280, spotted by Vlad Dogaru
> 
>  drivers/iio/pressure/bmp280.c | 203 ++++++++++++++++++++++++++++++++++++++----
>  1 file changed, 185 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/iio/pressure/bmp280.c b/drivers/iio/pressure/bmp280.c
> index dcf3b0a..2f1498e 100644
> --- a/drivers/iio/pressure/bmp280.c
> +++ b/drivers/iio/pressure/bmp280.c
> @@ -48,19 +48,21 @@
>  
>  #define BMP280_OSRS_TEMP_MASK		(BIT(7) | BIT(6) | BIT(5))
>  #define BMP280_OSRS_TEMP_SKIP		0
> -#define BMP280_OSRS_TEMP_1X		BIT(5)
> -#define BMP280_OSRS_TEMP_2X		BIT(6)
> -#define BMP280_OSRS_TEMP_4X		(BIT(6) | BIT(5))
> -#define BMP280_OSRS_TEMP_8X		BIT(7)
> -#define BMP280_OSRS_TEMP_16X		(BIT(7) | BIT(5))
> +#define BMP280_OSRS_TEMP_X(osrs_t)	((osrs_t) << 5)
> +#define BMP280_OSRS_TEMP_1X		BMP280_OSRS_TEMP_X(1)
> +#define BMP280_OSRS_TEMP_2X		BMP280_OSRS_TEMP_X(2)
> +#define BMP280_OSRS_TEMP_4X		BMP280_OSRS_TEMP_X(3)
> +#define BMP280_OSRS_TEMP_8X		BMP280_OSRS_TEMP_X(4)
> +#define BMP280_OSRS_TEMP_16X		BMP280_OSRS_TEMP_X(5)
>  
>  #define BMP280_OSRS_PRESS_MASK		(BIT(4) | BIT(3) | BIT(2))
>  #define BMP280_OSRS_PRESS_SKIP		0
> -#define BMP280_OSRS_PRESS_1X		BIT(2)
> -#define BMP280_OSRS_PRESS_2X		BIT(3)
> -#define BMP280_OSRS_PRESS_4X		(BIT(3) | BIT(2))
> -#define BMP280_OSRS_PRESS_8X		BIT(4)
> -#define BMP280_OSRS_PRESS_16X		(BIT(4) | BIT(2))
> +#define BMP280_OSRS_PRESS_X(osrs_p)	((osrs_p) << 2)
> +#define BMP280_OSRS_PRESS_1X		BMP280_OSRS_PRESS_X(1)
> +#define BMP280_OSRS_PRESS_2X		BMP280_OSRS_PRESS_X(2)
> +#define BMP280_OSRS_PRESS_4X		BMP280_OSRS_PRESS_X(3)
> +#define BMP280_OSRS_PRESS_8X		BMP280_OSRS_PRESS_X(4)
> +#define BMP280_OSRS_PRESS_16X		BMP280_OSRS_PRESS_X(5)
>  
>  #define BMP280_MODE_MASK		(BIT(1) | BIT(0))
>  #define BMP280_MODE_SLEEP		0
> @@ -98,6 +100,10 @@ struct bmp280_data {
>  	struct regmap *regmap;
>  	const struct bmp280_chip_info *chip_info;
>  
> +	/* log of base 2 of oversampling rate */
> +	u8 oversampling_press;
> +	u8 oversampling_temp;
> +
>  	/*
>  	 * Carryover value from temperature conversion, used in pressure
>  	 * calculation.
> @@ -108,6 +114,12 @@ struct bmp280_data {
>  struct bmp280_chip_info {
>  	const struct regmap_config *regmap_config;
>  
> +	const int *oversampling_temp_avail;
> +	int num_oversampling_temp_avail;
> +
> +	const int *oversampling_press_avail;
> +	int num_oversampling_press_avail;
> +
>  	int (*chip_config)(struct bmp280_data *);
>  	int (*read_temp)(struct bmp280_data *, int *);
>  	int (*read_press)(struct bmp280_data *, int *, int *);
> @@ -123,11 +135,13 @@ enum { P1, P2, P3, P4, P5, P6, P7, P8, P9 };
>  static const struct iio_chan_spec bmp280_channels[] = {
>  	{
>  		.type = IIO_PRESSURE,
> -		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
> +				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
>  	},
>  	{
>  		.type = IIO_TEMP,
> -		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
> +				      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
>  	},
>  };
>  
> @@ -333,6 +347,21 @@ static int bmp280_read_raw(struct iio_dev *indio_dev,
>  			break;
>  		}
>  		break;
> +	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
> +		switch (chan->type) {
> +		case IIO_PRESSURE:
> +			*val = 1 << data->oversampling_press;
> +			ret = IIO_VAL_INT;
> +			break;
> +		case IIO_TEMP:
> +			*val = 1 << data->oversampling_temp;
> +			ret = IIO_VAL_INT;
> +			break;
> +		default:
> +			ret = -EINVAL;
> +			break;
> +		}
> +		break;
>  	default:
>  		ret = -EINVAL;
>  		break;
> @@ -343,22 +372,135 @@ static int bmp280_read_raw(struct iio_dev *indio_dev,
>  	return ret;
>  }
>  
> +static int bmp280_write_oversampling_ratio_temp(struct bmp280_data *data,
> +					       int val)
> +{
> +	int i;
> +	const int *avail = data->chip_info->oversampling_temp_avail;
> +	const int n = data->chip_info->num_oversampling_temp_avail;
> +
> +	for (i = 0; i < n; i++) {
> +		if (avail[i] == val) {
> +			data->oversampling_temp = ilog2(val);
> +
> +			return data->chip_info->chip_config(data);
> +		}
> +	}
> +	return -EINVAL;
> +}
> +
> +static int bmp280_write_oversampling_ratio_press(struct bmp280_data *data,
> +					       int val)
> +{
> +	int i;
> +	const int *avail = data->chip_info->oversampling_press_avail;
> +	const int n = data->chip_info->num_oversampling_press_avail;
> +
> +	for (i = 0; i < n; i++) {
> +		if (avail[i] == val) {
> +			data->oversampling_press = ilog2(val);
> +
> +			return data->chip_info->chip_config(data);
> +		}
> +	}
> +	return -EINVAL;
> +}
> +
> +static int bmp280_write_raw(struct iio_dev *indio_dev,
> +			    struct iio_chan_spec const *chan,
> +			    int val, int val2, long mask)
> +{
> +	int ret = 0;
> +	struct bmp280_data *data = iio_priv(indio_dev);
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
> +		mutex_lock(&data->lock);
> +		switch (chan->type) {
> +		case IIO_PRESSURE:
> +			ret = bmp280_write_oversampling_ratio_press(data, val);
> +			break;
> +		case IIO_TEMP:
> +			ret = bmp280_write_oversampling_ratio_temp(data, val);
> +			break;
> +		default:
> +			ret = -EINVAL;
> +			break;
> +		}
> +		mutex_unlock(&data->lock);
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	return ret;
> +}
> +
> +static ssize_t bmp280_show_avail(char *buf, const int *vals, const int n)
> +{
> +	size_t len = 0;
> +	int i;
> +
> +	for (i = 0; i < n; i++)
> +		len += scnprintf(buf + len, PAGE_SIZE - len, "%d ", vals[i]);
> +
> +	buf[len - 1] = '\n';
> +
> +	return len;
> +}
> +
> +static ssize_t bmp280_show_temp_oversampling_avail(struct device *dev,
> +				struct device_attribute *attr, char *buf)
> +{
> +	struct bmp280_data *data = iio_priv(dev_to_iio_dev(dev));
> +
> +	return bmp280_show_avail(buf, data->chip_info->oversampling_temp_avail,
> +				 data->chip_info->num_oversampling_temp_avail);
> +}
> +
> +static ssize_t bmp280_show_press_oversampling_avail(struct device *dev,
> +				struct device_attribute *attr, char *buf)
> +{
> +	struct bmp280_data *data = iio_priv(dev_to_iio_dev(dev));
> +
> +	return bmp280_show_avail(buf, data->chip_info->oversampling_press_avail,
> +				 data->chip_info->num_oversampling_press_avail);
> +}
> +
> +static IIO_DEVICE_ATTR(in_temp_oversampling_ratio_available,
> +	S_IRUGO, bmp280_show_temp_oversampling_avail, NULL, 0);
> +
> +static IIO_DEVICE_ATTR(in_pressure_oversampling_ratio_available,
> +	S_IRUGO, bmp280_show_press_oversampling_avail, NULL, 0);
> +
> +static struct attribute *bmp280_attributes[] = {
> +	&iio_dev_attr_in_temp_oversampling_ratio_available.dev_attr.attr,
> +	&iio_dev_attr_in_pressure_oversampling_ratio_available.dev_attr.attr,
> +	NULL,
> +};
> +
> +static const struct attribute_group bmp280_attrs_group = {
> +	.attrs = bmp280_attributes,
> +};
> +
>  static const struct iio_info bmp280_info = {
>  	.driver_module = THIS_MODULE,
>  	.read_raw = &bmp280_read_raw,
> +	.write_raw = &bmp280_write_raw,
> +	.attrs = &bmp280_attrs_group,
>  };
>  
>  static int bmp280_chip_config(struct bmp280_data *data)
>  {
>  	int ret;
> +	u8 osrs = BMP280_OSRS_TEMP_X(data->oversampling_temp + 1) |
> +		  BMP280_OSRS_PRESS_X(data->oversampling_press + 1);
>  
>  	ret = regmap_update_bits(data->regmap, BMP280_REG_CTRL_MEAS,
>  				 BMP280_OSRS_TEMP_MASK |
>  				 BMP280_OSRS_PRESS_MASK |
>  				 BMP280_MODE_MASK,
> -				 BMP280_OSRS_TEMP_2X |
> -				 BMP280_OSRS_PRESS_16X |
> -				 BMP280_MODE_NORMAL);
> +				 osrs | BMP280_MODE_NORMAL);
>  	if (ret < 0) {
>  		dev_err(&data->client->dev,
>  			"failed to write ctrl_meas register\n");
> @@ -377,8 +519,17 @@ static int bmp280_chip_config(struct bmp280_data *data)
>  	return ret;
>  }
>  
> +static const int bmp280_oversampling_avail[] = { 1, 2, 4, 8, 16 };
> +
>  static const struct bmp280_chip_info bmp280_chip_info = {
>  	.regmap_config = &bmp280_regmap_config,
> +
> +	.oversampling_temp_avail = bmp280_oversampling_avail,
> +	.num_oversampling_temp_avail = ARRAY_SIZE(bmp280_oversampling_avail),
> +
> +	.oversampling_press_avail = bmp280_oversampling_avail,
> +	.num_oversampling_press_avail = ARRAY_SIZE(bmp280_oversampling_avail),
> +
>  	.chip_config = bmp280_chip_config,
>  	.read_temp = bmp280_read_temp,
>  	.read_press = bmp280_read_press,
> @@ -433,7 +584,7 @@ static int bmp180_measure(struct bmp280_data *data, u8 ctrl_meas)
>  	if (ctrl_meas == BMP180_MEAS_TEMP)
>  		delay_us = 4500;
>  	else
> -		delay_us = conversion_time_max[ilog2(8)];
> +		delay_us = conversion_time_max[data->oversampling_press];
>  
>  	usleep_range(delay_us, delay_us + 1000);
>  
> @@ -573,7 +724,7 @@ static int bmp180_read_adc_press(struct bmp280_data *data, int *val)
>  {
>  	int ret;
>  	__be32 tmp = 0;
> -	u8 oss = ilog2(8);
> +	u8 oss = data->oversampling_press;
>  
>  	ret = bmp180_measure(data, BMP180_MEAS_PRESS_X(oss));
>  	if (ret)
> @@ -599,7 +750,7 @@ static u32 bmp180_compensate_press(struct bmp280_data *data, s32 adc_press)
>  	s32 x1, x2, x3, p;
>  	s32 b3, b6;
>  	u32 b4, b7;
> -	s32 oss = ilog2(8);
> +	s32 oss = data->oversampling_press;
>  	struct bmp180_calib calib;
>  
>  	ret = bmp180_read_calib(data, &calib);
> @@ -660,8 +811,20 @@ static int bmp180_chip_config(struct bmp280_data *data)
>  	return 0;
>  }
>  
> +static const int bmp180_oversampling_temp_avail[] = { 1 };
> +static const int bmp180_oversampling_press_avail[] = { 1, 2, 4, 8 };
> +
>  static const struct bmp280_chip_info bmp180_chip_info = {
>  	.regmap_config = &bmp180_regmap_config,
> +
> +	.oversampling_temp_avail = bmp180_oversampling_temp_avail,
> +	.num_oversampling_temp_avail =
> +		ARRAY_SIZE(bmp180_oversampling_temp_avail),
> +
> +	.oversampling_press_avail = bmp180_oversampling_press_avail,
> +	.num_oversampling_press_avail =
> +		ARRAY_SIZE(bmp180_oversampling_press_avail),
> +
>  	.chip_config = bmp180_chip_config,
>  	.read_temp = bmp180_read_temp,
>  	.read_press = bmp180_read_press,
> @@ -693,9 +856,13 @@ static int bmp280_probe(struct i2c_client *client,
>  	switch (id->driver_data) {
>  	case BMP180_CHIP_ID:
>  		data->chip_info = &bmp180_chip_info;
> +		data->oversampling_press = ilog2(8);
> +		data->oversampling_temp = ilog2(1);
>  		break;
>  	case BMP280_CHIP_ID:
>  		data->chip_info = &bmp280_chip_info;
> +		data->oversampling_press = ilog2(16);
> +		data->oversampling_temp = ilog2(2);
>  		break;
>  	default:
>  		return -EINVAL;
> -- 
> 2.5.0
> 

Re: [PATCH v3 0/2] iio: pressure: bmp280: add support for BMP180 and oversampling rate control

[Jonathan Cameron]

On 24/04/16 14:52, Akinobu Mita wrote:
> This series includes two patches: one that adds support for the BMP180
> chip, and the second which adds configuration for the oversampling ratio
> for both BMP180 and BMP280.
Both patches look good to me.  Will let them sit on the list until Vlad
has a chance to take another look and give an Ack / reviewed-by if he
is happy.

Thanks,

Jonathan
> 
> * v3
> - use single line comment style where possible suggested by Jonathan Cameron
> - remove double casts for calibration coefficients by using adequate data
>   types, suggested by Jonathan Cameron
> - fix oversampling register setting for bmp280, spotted by Vlad Dogaru
> 
> * v2
> - split into two patches
> - add error check for reading calibration data.
> - s/be16_to_cpu(0)/cpu_to_be16(0)/
> - default pressure oversampling ratio for bmp180 from x1 to x8
> - add kconfig dependency to not select if bmp085-i2c is enabled
> - create bmp280_chip_info includes all elements depending on the chip
> - add ACPI ids for bmp180
> 
> Akinobu Mita (2):
>   iio: pressure: bmp280: add support for BMP180
>   iio: pressure: bmp280: add ability to control oversampling rate
> 
>  drivers/iio/pressure/Kconfig  |   5 +-
>  drivers/iio/pressure/bmp280.c | 564 +++++++++++++++++++++++++++++++++++++++---
>  2 files changed, 538 insertions(+), 31 deletions(-)
>