iio: pressure: bmp280: split driver in logical parts
This splits the BMP280 driver in three logical parts: the core driver
bmp280-core that only operated on a struct device * and a struct regmap *,
the regmap driver bmp280-regmap that can be shared between I2C and other
transports and the I2C module driver bmp280-i2c.
Cleverly bake all functionality into a single object bmp280.o so that
we still get the same module binary built for the device in the end,
without any fuzz exporting symbols to the left and right.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
new file mode 100644
index 0000000..83b96fe
--- /dev/null
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -0,0 +1,968 @@
+/*
+ * Copyright (c) 2014 Intel Corporation
+ *
+ * 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
+ * https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BME280_DS001-11.pdf
+ */
+
+#define pr_fmt(fmt) "bmp280: " fmt
+
+#include <linux/device.h>
+#include <linux/regmap.h>
+#include <linux/delay.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/gpio/consumer.h>
+#include <linux/regulator/consumer.h>
+
+#include "bmp280.h"
+
+struct bmp280_data {
+ struct device *dev;
+ struct mutex lock;
+ struct regmap *regmap;
+ const struct bmp280_chip_info *chip_info;
+ struct regulator *vddd;
+ struct regulator *vdda;
+ unsigned int start_up_time; /* in milliseconds */
+
+ /* log of base 2 of oversampling rate */
+ u8 oversampling_press;
+ u8 oversampling_temp;
+ u8 oversampling_humid;
+
+ /*
+ * Carryover value from temperature conversion, used in pressure
+ * calculation.
+ */
+ s32 t_fine;
+};
+
+struct bmp280_chip_info {
+ const int *oversampling_temp_avail;
+ int num_oversampling_temp_avail;
+
+ const int *oversampling_press_avail;
+ int num_oversampling_press_avail;
+
+ const int *oversampling_humid_avail;
+ int num_oversampling_humid_avail;
+
+ int (*chip_config)(struct bmp280_data *);
+ int (*read_temp)(struct bmp280_data *, int *);
+ int (*read_press)(struct bmp280_data *, int *, int *);
+ int (*read_humid)(struct bmp280_data *, int *, int *);
+};
+
+/*
+ * These enums are used for indexing into the array of compensation
+ * parameters for BMP280.
+ */
+enum { T1, T2, T3 };
+enum { P1, P2, P3, P4, P5, P6, P7, P8, P9 };
+
+static const struct iio_chan_spec bmp280_channels[] = {
+ {
+ .type = IIO_PRESSURE,
+ .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) |
+ BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+ },
+ {
+ .type = IIO_HUMIDITYRELATIVE,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
+ BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+ },
+};
+
+/*
+ * Returns humidity in percent, resolution is 0.01 percent. Output value of
+ * "47445" represents 47445/1024 = 46.333 %RH.
+ *
+ * Taken from BME280 datasheet, Section 4.2.3, "Compensation formula".
+ */
+
+static u32 bmp280_compensate_humidity(struct bmp280_data *data,
+ s32 adc_humidity)
+{
+ struct device *dev = data->dev;
+ unsigned int H1, H3, tmp;
+ int H2, H4, H5, H6, ret, var;
+
+ ret = regmap_read(data->regmap, BMP280_REG_COMP_H1, &H1);
+ if (ret < 0) {
+ dev_err(dev, "failed to read H1 comp value\n");
+ return ret;
+ }
+
+ ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H2, &tmp, 2);
+ if (ret < 0) {
+ dev_err(dev, "failed to read H2 comp value\n");
+ return ret;
+ }
+ H2 = sign_extend32(le16_to_cpu(tmp), 15);
+
+ ret = regmap_read(data->regmap, BMP280_REG_COMP_H3, &H3);
+ if (ret < 0) {
+ dev_err(dev, "failed to read H3 comp value\n");
+ return ret;
+ }
+
+ ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H4, &tmp, 2);
+ if (ret < 0) {
+ dev_err(dev, "failed to read H4 comp value\n");
+ return ret;
+ }
+ H4 = sign_extend32(((be16_to_cpu(tmp) >> 4) & 0xff0) |
+ (be16_to_cpu(tmp) & 0xf), 11);
+
+ ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H5, &tmp, 2);
+ if (ret < 0) {
+ dev_err(dev, "failed to read H5 comp value\n");
+ return ret;
+ }
+ H5 = sign_extend32(((le16_to_cpu(tmp) >> 4) & 0xfff), 11);
+
+ ret = regmap_read(data->regmap, BMP280_REG_COMP_H6, &tmp);
+ if (ret < 0) {
+ dev_err(dev, "failed to read H6 comp value\n");
+ return ret;
+ }
+ H6 = sign_extend32(tmp, 7);
+
+ var = ((s32)data->t_fine) - 76800;
+ var = ((((adc_humidity << 14) - (H4 << 20) - (H5 * var)) + 16384) >> 15)
+ * (((((((var * H6) >> 10) * (((var * H3) >> 11) + 32768)) >> 10)
+ + 2097152) * H2 + 8192) >> 14);
+ var -= ((((var >> 15) * (var >> 15)) >> 7) * H1) >> 4;
+
+ return var >> 12;
+};
+
+/*
+ * Returns temperature in DegC, resolution is 0.01 DegC. Output value of
+ * "5123" equals 51.23 DegC. t_fine carries fine temperature as global
+ * value.
+ *
+ * Taken from datasheet, Section 3.11.3, "Compensation formula".
+ */
+static s32 bmp280_compensate_temp(struct bmp280_data *data,
+ s32 adc_temp)
+{
+ int ret;
+ s32 var1, var2;
+ __le16 buf[BMP280_COMP_TEMP_REG_COUNT / 2];
+
+ ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_TEMP_START,
+ buf, BMP280_COMP_TEMP_REG_COUNT);
+ if (ret < 0) {
+ dev_err(data->dev,
+ "failed to read temperature calibration parameters\n");
+ return ret;
+ }
+
+ /*
+ * The double casts are necessary because le16_to_cpu returns an
+ * unsigned 16-bit value. Casting that value directly to a
+ * signed 32-bit will not do proper sign extension.
+ *
+ * Conversely, T1 and P1 are unsigned values, so they can be
+ * cast straight to the larger type.
+ */
+ var1 = (((adc_temp >> 3) - ((s32)le16_to_cpu(buf[T1]) << 1)) *
+ ((s32)(s16)le16_to_cpu(buf[T2]))) >> 11;
+ var2 = (((((adc_temp >> 4) - ((s32)le16_to_cpu(buf[T1]))) *
+ ((adc_temp >> 4) - ((s32)le16_to_cpu(buf[T1])))) >> 12) *
+ ((s32)(s16)le16_to_cpu(buf[T3]))) >> 14;
+ data->t_fine = var1 + var2;
+
+ return (data->t_fine * 5 + 128) >> 8;
+}
+
+/*
+ * Returns pressure in Pa as unsigned 32 bit integer in Q24.8 format (24
+ * integer bits and 8 fractional bits). Output value of "24674867"
+ * represents 24674867/256 = 96386.2 Pa = 963.862 hPa
+ *
+ * Taken from datasheet, Section 3.11.3, "Compensation formula".
+ */
+static u32 bmp280_compensate_press(struct bmp280_data *data,
+ s32 adc_press)
+{
+ int ret;
+ s64 var1, var2, p;
+ __le16 buf[BMP280_COMP_PRESS_REG_COUNT / 2];
+
+ ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_PRESS_START,
+ buf, BMP280_COMP_PRESS_REG_COUNT);
+ if (ret < 0) {
+ dev_err(data->dev,
+ "failed to read pressure calibration parameters\n");
+ return ret;
+ }
+
+ var1 = ((s64)data->t_fine) - 128000;
+ var2 = var1 * var1 * (s64)(s16)le16_to_cpu(buf[P6]);
+ var2 += (var1 * (s64)(s16)le16_to_cpu(buf[P5])) << 17;
+ var2 += ((s64)(s16)le16_to_cpu(buf[P4])) << 35;
+ var1 = ((var1 * var1 * (s64)(s16)le16_to_cpu(buf[P3])) >> 8) +
+ ((var1 * (s64)(s16)le16_to_cpu(buf[P2])) << 12);
+ var1 = ((((s64)1) << 47) + var1) * ((s64)le16_to_cpu(buf[P1])) >> 33;
+
+ if (var1 == 0)
+ return 0;
+
+ p = ((((s64)1048576 - adc_press) << 31) - var2) * 3125;
+ p = div64_s64(p, var1);
+ var1 = (((s64)(s16)le16_to_cpu(buf[P9])) * (p >> 13) * (p >> 13)) >> 25;
+ var2 = (((s64)(s16)le16_to_cpu(buf[P8])) * p) >> 19;
+ p = ((p + var1 + var2) >> 8) + (((s64)(s16)le16_to_cpu(buf[P7])) << 4);
+
+ return (u32)p;
+}
+
+static int bmp280_read_temp(struct bmp280_data *data,
+ int *val)
+{
+ int ret;
+ __be32 tmp = 0;
+ s32 adc_temp, comp_temp;
+
+ ret = regmap_bulk_read(data->regmap, BMP280_REG_TEMP_MSB,
+ (u8 *) &tmp, 3);
+ if (ret < 0) {
+ dev_err(data->dev, "failed to read temperature\n");
+ return ret;
+ }
+
+ adc_temp = be32_to_cpu(tmp) >> 12;
+ comp_temp = bmp280_compensate_temp(data, adc_temp);
+
+ /*
+ * val might be NULL if we're called by the read_press routine,
+ * who only cares about the carry over t_fine value.
+ */
+ if (val) {
+ *val = comp_temp * 10;
+ return IIO_VAL_INT;
+ }
+
+ return 0;
+}
+
+static int bmp280_read_press(struct bmp280_data *data,
+ int *val, int *val2)
+{
+ int ret;
+ __be32 tmp = 0;
+ s32 adc_press;
+ u32 comp_press;
+
+ /* Read and compensate temperature so we get a reading of t_fine. */
+ ret = bmp280_read_temp(data, NULL);
+ if (ret < 0)
+ return ret;
+
+ ret = regmap_bulk_read(data->regmap, BMP280_REG_PRESS_MSB,
+ (u8 *) &tmp, 3);
+ if (ret < 0) {
+ dev_err(data->dev, "failed to read pressure\n");
+ return ret;
+ }
+
+ adc_press = be32_to_cpu(tmp) >> 12;
+ comp_press = bmp280_compensate_press(data, adc_press);
+
+ *val = comp_press;
+ *val2 = 256000;
+
+ return IIO_VAL_FRACTIONAL;
+}
+
+static int bmp280_read_humid(struct bmp280_data *data, int *val, int *val2)
+{
+ int ret;
+ __be16 tmp = 0;
+ s32 adc_humidity;
+ u32 comp_humidity;
+
+ /* Read and compensate temperature so we get a reading of t_fine. */
+ ret = bmp280_read_temp(data, NULL);
+ if (ret < 0)
+ return ret;
+
+ ret = regmap_bulk_read(data->regmap, BMP280_REG_HUMIDITY_MSB,
+ (u8 *) &tmp, 2);
+ if (ret < 0) {
+ dev_err(data->dev, "failed to read humidity\n");
+ return ret;
+ }
+
+ adc_humidity = be16_to_cpu(tmp);
+ comp_humidity = bmp280_compensate_humidity(data, adc_humidity);
+
+ *val = comp_humidity;
+ *val2 = 1024;
+
+ return IIO_VAL_FRACTIONAL;
+}
+
+static int bmp280_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ int ret;
+ struct bmp280_data *data = iio_priv(indio_dev);
+
+ mutex_lock(&data->lock);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_PROCESSED:
+ switch (chan->type) {
+ case IIO_HUMIDITYRELATIVE:
+ ret = data->chip_info->read_humid(data, val, val2);
+ break;
+ case IIO_PRESSURE:
+ ret = data->chip_info->read_press(data, val, val2);
+ break;
+ case IIO_TEMP:
+ ret = data->chip_info->read_temp(data, val);
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+ break;
+ case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+ switch (chan->type) {
+ case IIO_HUMIDITYRELATIVE:
+ *val = 1 << data->oversampling_humid;
+ ret = IIO_VAL_INT;
+ break;
+ 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;
+ }
+
+ mutex_unlock(&data->lock);
+
+ return ret;
+}
+
+static int bmp280_write_oversampling_ratio_humid(struct bmp280_data *data,
+ int val)
+{
+ int i;
+ const int *avail = data->chip_info->oversampling_humid_avail;
+ const int n = data->chip_info->num_oversampling_humid_avail;
+
+ for (i = 0; i < n; i++) {
+ if (avail[i] == val) {
+ data->oversampling_humid = ilog2(val);
+
+ return data->chip_info->chip_config(data);
+ }
+ }
+ return -EINVAL;
+}
+
+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_HUMIDITYRELATIVE:
+ ret = bmp280_write_oversampling_ratio_humid(data, val);
+ break;
+ 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,
+ osrs | BMP280_MODE_NORMAL);
+ if (ret < 0) {
+ dev_err(data->dev,
+ "failed to write ctrl_meas register\n");
+ return ret;
+ }
+
+ ret = regmap_update_bits(data->regmap, BMP280_REG_CONFIG,
+ BMP280_FILTER_MASK,
+ BMP280_FILTER_4X);
+ if (ret < 0) {
+ dev_err(data->dev,
+ "failed to write config register\n");
+ return ret;
+ }
+
+ return ret;
+}
+
+static const int bmp280_oversampling_avail[] = { 1, 2, 4, 8, 16 };
+
+static const struct bmp280_chip_info bmp280_chip_info = {
+ .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,
+};
+
+static int bme280_chip_config(struct bmp280_data *data)
+{
+ int ret = bmp280_chip_config(data);
+ u8 osrs = BMP280_OSRS_HUMIDITIY_X(data->oversampling_humid + 1);
+
+ if (ret < 0)
+ return ret;
+
+ return regmap_update_bits(data->regmap, BMP280_REG_CTRL_HUMIDITY,
+ BMP280_OSRS_HUMIDITY_MASK, osrs);
+}
+
+static const struct bmp280_chip_info bme280_chip_info = {
+ .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),
+
+ .oversampling_humid_avail = bmp280_oversampling_avail,
+ .num_oversampling_humid_avail = ARRAY_SIZE(bmp280_oversampling_avail),
+
+ .chip_config = bme280_chip_config,
+ .read_temp = bmp280_read_temp,
+ .read_press = bmp280_read_press,
+ .read_humid = bmp280_read_humid,
+};
+
+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[data->oversampling_press];
+
+ 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->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 = data->oversampling_press;
+
+ ret = bmp180_measure(data, BMP180_MEAS_PRESS_X(oss));
+ if (ret)
+ return ret;
+
+ ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB, (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 = data->oversampling_press;
+ struct bmp180_calib calib;
+
+ ret = bmp180_read_calib(data, &calib);
+ if (ret < 0) {
+ dev_err(data->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 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 = {
+ .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,
+};
+
+int bmp280_common_probe(struct device *dev,
+ struct regmap *regmap,
+ unsigned int chip,
+ const char *name)
+{
+ int ret;
+ struct iio_dev *indio_dev;
+ struct bmp280_data *data;
+ unsigned int chip_id;
+ struct gpio_desc *gpiod;
+
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ data = iio_priv(indio_dev);
+ mutex_init(&data->lock);
+ data->dev = dev;
+
+ indio_dev->dev.parent = dev;
+ indio_dev->name = name;
+ indio_dev->channels = bmp280_channels;
+ indio_dev->info = &bmp280_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+
+ switch (chip) {
+ case BMP180_CHIP_ID:
+ indio_dev->num_channels = 2;
+ data->chip_info = &bmp180_chip_info;
+ data->oversampling_press = ilog2(8);
+ data->oversampling_temp = ilog2(1);
+ data->start_up_time = 10;
+ break;
+ case BMP280_CHIP_ID:
+ indio_dev->num_channels = 2;
+ data->chip_info = &bmp280_chip_info;
+ data->oversampling_press = ilog2(16);
+ data->oversampling_temp = ilog2(2);
+ data->start_up_time = 2;
+ break;
+ case BME280_CHIP_ID:
+ indio_dev->num_channels = 3;
+ data->chip_info = &bme280_chip_info;
+ data->oversampling_press = ilog2(16);
+ data->oversampling_humid = ilog2(16);
+ data->oversampling_temp = ilog2(2);
+ data->start_up_time = 2;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /* Bring up regulators */
+ data->vddd = devm_regulator_get(dev, "vddd");
+ if (IS_ERR(data->vddd)) {
+ dev_err(dev, "failed to get VDDD regulator\n");
+ return PTR_ERR(data->vddd);
+ }
+ ret = regulator_enable(data->vddd);
+ if (ret) {
+ dev_err(dev, "failed to enable VDDD regulator\n");
+ return ret;
+ }
+ data->vdda = devm_regulator_get(dev, "vdda");
+ if (IS_ERR(data->vdda)) {
+ dev_err(dev, "failed to get VDDA regulator\n");
+ ret = PTR_ERR(data->vddd);
+ goto out_disable_vddd;
+ }
+ ret = regulator_enable(data->vdda);
+ if (ret) {
+ dev_err(dev, "failed to enable VDDA regulator\n");
+ goto out_disable_vddd;
+ }
+ /* Wait to make sure we started up properly */
+ mdelay(data->start_up_time);
+
+ /* Bring chip out of reset if there is an assigned GPIO line */
+ gpiod = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
+ /* Deassert the signal */
+ if (!IS_ERR(gpiod)) {
+ dev_info(dev, "release reset\n");
+ gpiod_set_value(gpiod, 0);
+ }
+
+ data->regmap = regmap;
+ ret = regmap_read(regmap, BMP280_REG_ID, &chip_id);
+ if (ret < 0)
+ goto out_disable_vdda;
+ if (chip_id != chip) {
+ dev_err(dev, "bad chip id: expected %x got %x\n",
+ chip, chip_id);
+ ret = -EINVAL;
+ goto out_disable_vdda;
+ }
+
+ ret = data->chip_info->chip_config(data);
+ if (ret < 0)
+ goto out_disable_vdda;
+
+ dev_set_drvdata(dev, indio_dev);
+
+ ret = iio_device_register(indio_dev);
+ if (ret)
+ goto out_disable_vdda;
+
+ return 0;
+
+out_disable_vdda:
+ regulator_disable(data->vdda);
+out_disable_vddd:
+ regulator_disable(data->vddd);
+ return ret;
+}
+
+int bmp280_common_remove(struct device *dev)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct bmp280_data *data = iio_priv(indio_dev);
+
+ iio_device_unregister(indio_dev);
+ regulator_disable(data->vdda);
+ regulator_disable(data->vddd);
+ return 0;
+}