diff options
Diffstat (limited to 'drivers/iio/pressure/bmp280-core.c')
| -rw-r--r-- | drivers/iio/pressure/bmp280-core.c | 1174 |
1 files changed, 1174 insertions, 0 deletions
diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c new file mode 100644 index 000000000..919a338d9 --- /dev/null +++ b/drivers/iio/pressure/bmp280-core.c @@ -0,0 +1,1174 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2010 Christoph Mair <christoph.mair@gmail.com> + * Copyright (c) 2012 Bosch Sensortec GmbH + * Copyright (c) 2012 Unixphere AB + * Copyright (c) 2014 Intel Corporation + * Copyright (c) 2016 Linus Walleij <linus.walleij@linaro.org> + * + * Driver for Bosch Sensortec BMP180 and BMP280 digital pressure sensor. + * + * 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/module.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 <linux/interrupt.h> +#include <linux/irq.h> /* For irq_get_irq_data() */ +#include <linux/completion.h> +#include <linux/pm_runtime.h> +#include <linux/random.h> + +#include "bmp280.h" + +/* + * 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; +}; + +/* See datasheet Section 4.2.2. */ +struct bmp280_calib { + u16 T1; + s16 T2; + s16 T3; + u16 P1; + s16 P2; + s16 P3; + s16 P4; + s16 P5; + s16 P6; + s16 P7; + s16 P8; + s16 P9; + u8 H1; + s16 H2; + u8 H3; + s16 H4; + s16 H5; + s8 H6; +}; + +static const char *const bmp280_supply_names[] = { + "vddd", "vdda" +}; + +#define BMP280_NUM_SUPPLIES ARRAY_SIZE(bmp280_supply_names) + +struct bmp280_data { + struct device *dev; + struct mutex lock; + struct regmap *regmap; + struct completion done; + bool use_eoc; + const struct bmp280_chip_info *chip_info; + union { + struct bmp180_calib bmp180; + struct bmp280_calib bmp280; + } calib; + struct regulator_bulk_data supplies[BMP280_NUM_SUPPLIES]; + unsigned int start_up_time; /* in microseconds */ + + /* 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), + }, +}; + +static int bmp280_read_calib(struct bmp280_data *data, + struct bmp280_calib *calib, + unsigned int chip) +{ + int ret; + unsigned int tmp; + __le16 l16; + __be16 b16; + struct device *dev = data->dev; + __le16 t_buf[BMP280_COMP_TEMP_REG_COUNT / 2]; + __le16 p_buf[BMP280_COMP_PRESS_REG_COUNT / 2]; + + /* Read temperature calibration values. */ + ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_TEMP_START, + t_buf, BMP280_COMP_TEMP_REG_COUNT); + if (ret < 0) { + dev_err(data->dev, + "failed to read temperature calibration parameters\n"); + return ret; + } + + /* Toss the temperature calibration data into the entropy pool */ + add_device_randomness(t_buf, sizeof(t_buf)); + + calib->T1 = le16_to_cpu(t_buf[T1]); + calib->T2 = le16_to_cpu(t_buf[T2]); + calib->T3 = le16_to_cpu(t_buf[T3]); + + /* Read pressure calibration values. */ + ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_PRESS_START, + p_buf, BMP280_COMP_PRESS_REG_COUNT); + if (ret < 0) { + dev_err(data->dev, + "failed to read pressure calibration parameters\n"); + return ret; + } + + /* Toss the pressure calibration data into the entropy pool */ + add_device_randomness(p_buf, sizeof(p_buf)); + + calib->P1 = le16_to_cpu(p_buf[P1]); + calib->P2 = le16_to_cpu(p_buf[P2]); + calib->P3 = le16_to_cpu(p_buf[P3]); + calib->P4 = le16_to_cpu(p_buf[P4]); + calib->P5 = le16_to_cpu(p_buf[P5]); + calib->P6 = le16_to_cpu(p_buf[P6]); + calib->P7 = le16_to_cpu(p_buf[P7]); + calib->P8 = le16_to_cpu(p_buf[P8]); + calib->P9 = le16_to_cpu(p_buf[P9]); + + /* + * Read humidity calibration values. + * Due to some odd register addressing we cannot just + * do a big bulk read. Instead, we have to read each Hx + * value separately and sometimes do some bit shifting... + * Humidity data is only available on BME280. + */ + if (chip != BME280_CHIP_ID) + return 0; + + ret = regmap_read(data->regmap, BMP280_REG_COMP_H1, &tmp); + if (ret < 0) { + dev_err(dev, "failed to read H1 comp value\n"); + return ret; + } + calib->H1 = tmp; + + ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H2, &l16, 2); + if (ret < 0) { + dev_err(dev, "failed to read H2 comp value\n"); + return ret; + } + calib->H2 = sign_extend32(le16_to_cpu(l16), 15); + + ret = regmap_read(data->regmap, BMP280_REG_COMP_H3, &tmp); + if (ret < 0) { + dev_err(dev, "failed to read H3 comp value\n"); + return ret; + } + calib->H3 = tmp; + + ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H4, &b16, 2); + if (ret < 0) { + dev_err(dev, "failed to read H4 comp value\n"); + return ret; + } + calib->H4 = sign_extend32(((be16_to_cpu(b16) >> 4) & 0xff0) | + (be16_to_cpu(b16) & 0xf), 11); + + ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H5, &l16, 2); + if (ret < 0) { + dev_err(dev, "failed to read H5 comp value\n"); + return ret; + } + calib->H5 = sign_extend32(((le16_to_cpu(l16) >> 4) & 0xfff), 11); + + 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; + } + calib->H6 = sign_extend32(tmp, 7); + + return 0; +} +/* + * 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) +{ + s32 var; + struct bmp280_calib *calib = &data->calib.bmp280; + + var = ((s32)data->t_fine) - (s32)76800; + var = ((((adc_humidity << 14) - (calib->H4 << 20) - (calib->H5 * var)) + + (s32)16384) >> 15) * (((((((var * calib->H6) >> 10) + * (((var * (s32)calib->H3) >> 11) + (s32)32768)) >> 10) + + (s32)2097152) * calib->H2 + 8192) >> 14); + var -= ((((var >> 15) * (var >> 15)) >> 7) * (s32)calib->H1) >> 4; + + var = clamp_val(var, 0, 419430400); + + 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) +{ + s32 var1, var2; + struct bmp280_calib *calib = &data->calib.bmp280; + + var1 = (((adc_temp >> 3) - ((s32)calib->T1 << 1)) * + ((s32)calib->T2)) >> 11; + var2 = (((((adc_temp >> 4) - ((s32)calib->T1)) * + ((adc_temp >> 4) - ((s32)calib->T1))) >> 12) * + ((s32)calib->T3)) >> 14; + 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) +{ + s64 var1, var2, p; + struct bmp280_calib *calib = &data->calib.bmp280; + + var1 = ((s64)data->t_fine) - 128000; + var2 = var1 * var1 * (s64)calib->P6; + var2 += (var1 * (s64)calib->P5) << 17; + var2 += ((s64)calib->P4) << 35; + var1 = ((var1 * var1 * (s64)calib->P3) >> 8) + + ((var1 * (s64)calib->P2) << 12); + var1 = ((((s64)1) << 47) + var1) * ((s64)calib->P1) >> 33; + + if (var1 == 0) + return 0; + + p = ((((s64)1048576 - adc_press) << 31) - var2) * 3125; + p = div64_s64(p, var1); + var1 = (((s64)calib->P9) * (p >> 13) * (p >> 13)) >> 25; + var2 = ((s64)(calib->P8) * p) >> 19; + p = ((p + var1 + var2) >> 8) + (((s64)calib->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, &tmp, 3); + if (ret < 0) { + dev_err(data->dev, "failed to read temperature\n"); + return ret; + } + + adc_temp = be32_to_cpu(tmp) >> 12; + if (adc_temp == BMP280_TEMP_SKIPPED) { + /* reading was skipped */ + dev_err(data->dev, "reading temperature skipped\n"); + return -EIO; + } + comp_temp = bmp280_compensate_temp(data, adc_temp); + + /* + * val might be NULL if we're called by the read_press routine, + * who only cares about the carry over t_fine value. + */ + if (val) { + *val = comp_temp * 10; + return IIO_VAL_INT; + } + + return 0; +} + +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, &tmp, 3); + if (ret < 0) { + dev_err(data->dev, "failed to read pressure\n"); + return ret; + } + + adc_press = be32_to_cpu(tmp) >> 12; + if (adc_press == BMP280_PRESS_SKIPPED) { + /* reading was skipped */ + dev_err(data->dev, "reading pressure skipped\n"); + return -EIO; + } + comp_press = bmp280_compensate_press(data, adc_press); + + *val = comp_press; + *val2 = 256000; + + return IIO_VAL_FRACTIONAL; +} + +static int bmp280_read_humid(struct bmp280_data *data, int *val, int *val2) +{ + __be16 tmp; + int ret; + 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, &tmp, 2); + if (ret < 0) { + dev_err(data->dev, "failed to read humidity\n"); + return ret; + } + + adc_humidity = be16_to_cpu(tmp); + if (adc_humidity == BMP280_HUMIDITY_SKIPPED) { + /* reading was skipped */ + dev_err(data->dev, "reading humidity skipped\n"); + return -EIO; + } + comp_humidity = bmp280_compensate_humidity(data, adc_humidity); + + *val = comp_humidity * 1000 / 1024; + + return IIO_VAL_INT; +} + +static int bmp280_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + int ret; + struct bmp280_data *data = iio_priv(indio_dev); + + pm_runtime_get_sync(data->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); + pm_runtime_mark_last_busy(data->dev); + pm_runtime_put_autosuspend(data->dev); + + 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: + pm_runtime_get_sync(data->dev); + 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); + pm_runtime_mark_last_busy(data->dev); + pm_runtime_put_autosuspend(data->dev); + break; + default: + return -EINVAL; + } + + return ret; +} + +static int bmp280_read_avail(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + const int **vals, int *type, int *length, + long mask) +{ + struct bmp280_data *data = iio_priv(indio_dev); + + switch (mask) { + case IIO_CHAN_INFO_OVERSAMPLING_RATIO: + switch (chan->type) { + case IIO_PRESSURE: + *vals = data->chip_info->oversampling_press_avail; + *length = data->chip_info->num_oversampling_press_avail; + break; + case IIO_TEMP: + *vals = data->chip_info->oversampling_temp_avail; + *length = data->chip_info->num_oversampling_temp_avail; + break; + default: + return -EINVAL; + } + *type = IIO_VAL_INT; + return IIO_AVAIL_LIST; + default: + return -EINVAL; + } +} + +static const struct iio_info bmp280_info = { + .read_raw = &bmp280_read_raw, + .read_avail = &bmp280_read_avail, + .write_raw = &bmp280_write_raw, +}; + +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_write_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; + u8 osrs = BMP280_OSRS_HUMIDITIY_X(data->oversampling_humid + 1); + + /* + * Oversampling of humidity must be set before oversampling of + * temperature/pressure is set to become effective. + */ + ret = regmap_update_bits(data->regmap, BMP280_REG_CTRL_HUMIDITY, + BMP280_OSRS_HUMIDITY_MASK, osrs); + + if (ret < 0) + return ret; + + return bmp280_chip_config(data); +} + +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; + + if (data->use_eoc) + reinit_completion(&data->done); + + ret = regmap_write(data->regmap, BMP280_REG_CTRL_MEAS, ctrl_meas); + if (ret) + return ret; + + if (data->use_eoc) { + /* + * If we have a completion interrupt, use it, wait up to + * 100ms. The longest conversion time listed is 76.5 ms for + * advanced resolution mode. + */ + ret = wait_for_completion_timeout(&data->done, + 1 + msecs_to_jiffies(100)); + if (!ret) + dev_err(data->dev, "timeout waiting for completion\n"); + } else { + 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) +{ + __be16 tmp; + int ret; + + ret = bmp180_measure(data, BMP180_MEAS_TEMP); + if (ret) + return ret; + + ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB, &tmp, 2); + if (ret) + return ret; + + *val = be16_to_cpu(tmp); + + return 0; +} + +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; + } + + /* Toss the calibration data into the entropy pool */ + add_device_randomness(buf, sizeof(buf)); + + calib->AC1 = be16_to_cpu(buf[AC1]); + calib->AC2 = be16_to_cpu(buf[AC2]); + calib->AC3 = be16_to_cpu(buf[AC3]); + calib->AC4 = be16_to_cpu(buf[AC4]); + calib->AC5 = be16_to_cpu(buf[AC5]); + calib->AC6 = be16_to_cpu(buf[AC6]); + calib->B1 = be16_to_cpu(buf[B1]); + calib->B2 = be16_to_cpu(buf[B2]); + calib->MB = be16_to_cpu(buf[MB]); + calib->MC = be16_to_cpu(buf[MC]); + calib->MD = be16_to_cpu(buf[MD]); + + 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) +{ + s32 x1, x2; + struct bmp180_calib *calib = &data->calib.bmp180; + + 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, &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) +{ + s32 x1, x2, x3, p; + s32 b3, b6; + u32 b4, b7; + s32 oss = data->oversampling_press; + struct bmp180_calib *calib = &data->calib.bmp180; + + 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, +}; + +static irqreturn_t bmp085_eoc_irq(int irq, void *d) +{ + struct bmp280_data *data = d; + + complete(&data->done); + + return IRQ_HANDLED; +} + +static int bmp085_fetch_eoc_irq(struct device *dev, + const char *name, + int irq, + struct bmp280_data *data) +{ + unsigned long irq_trig; + int ret; + + irq_trig = irqd_get_trigger_type(irq_get_irq_data(irq)); + if (irq_trig != IRQF_TRIGGER_RISING) { + dev_err(dev, "non-rising trigger given for EOC interrupt, trying to enforce it\n"); + irq_trig = IRQF_TRIGGER_RISING; + } + + init_completion(&data->done); + + ret = devm_request_threaded_irq(dev, + irq, + bmp085_eoc_irq, + NULL, + irq_trig, + name, + data); + if (ret) { + /* Bail out without IRQ but keep the driver in place */ + dev_err(dev, "unable to request DRDY IRQ\n"); + return 0; + } + + data->use_eoc = true; + return 0; +} + +static void bmp280_pm_disable(void *data) +{ + struct device *dev = data; + + pm_runtime_get_sync(dev); + pm_runtime_put_noidle(dev); + pm_runtime_disable(dev); +} + +static void bmp280_regulators_disable(void *data) +{ + struct regulator_bulk_data *supplies = data; + + regulator_bulk_disable(BMP280_NUM_SUPPLIES, supplies); +} + +int bmp280_common_probe(struct device *dev, + struct regmap *regmap, + unsigned int chip, + const char *name, + int irq) +{ + 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->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 = 10000; + break; + case BMP280_CHIP_ID: + indio_dev->num_channels = 2; + data->chip_info = &bmp280_chip_info; + data->oversampling_press = ilog2(16); + data->oversampling_temp = ilog2(2); + data->start_up_time = 2000; + break; + case BME280_CHIP_ID: + indio_dev->num_channels = 3; + data->chip_info = &bme280_chip_info; + data->oversampling_press = ilog2(16); + data->oversampling_humid = ilog2(16); + data->oversampling_temp = ilog2(2); + data->start_up_time = 2000; + break; + default: + return -EINVAL; + } + + /* Bring up regulators */ + regulator_bulk_set_supply_names(data->supplies, + bmp280_supply_names, + BMP280_NUM_SUPPLIES); + + ret = devm_regulator_bulk_get(dev, + BMP280_NUM_SUPPLIES, data->supplies); + if (ret) { + dev_err(dev, "failed to get regulators\n"); + return ret; + } + + ret = regulator_bulk_enable(BMP280_NUM_SUPPLIES, data->supplies); + if (ret) { + dev_err(dev, "failed to enable regulators\n"); + return ret; + } + + ret = devm_add_action_or_reset(dev, bmp280_regulators_disable, + data->supplies); + if (ret) + return ret; + + /* Wait to make sure we started up properly */ + usleep_range(data->start_up_time, data->start_up_time + 100); + + /* Bring chip out of reset if there is an assigned GPIO line */ + gpiod = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH); + /* Deassert the signal */ + if (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) + return ret; + if (chip_id != chip) { + dev_err(dev, "bad chip id: expected %x got %x\n", + chip, chip_id); + return -EINVAL; + } + + ret = data->chip_info->chip_config(data); + if (ret < 0) + return ret; + + dev_set_drvdata(dev, indio_dev); + + /* + * Some chips have calibration parameters "programmed into the devices' + * non-volatile memory during production". Let's read them out at probe + * time once. They will not change. + */ + if (chip_id == BMP180_CHIP_ID) { + ret = bmp180_read_calib(data, &data->calib.bmp180); + if (ret < 0) { + dev_err(data->dev, + "failed to read calibration coefficients\n"); + return ret; + } + } else if (chip_id == BMP280_CHIP_ID || chip_id == BME280_CHIP_ID) { + ret = bmp280_read_calib(data, &data->calib.bmp280, chip_id); + if (ret < 0) { + dev_err(data->dev, + "failed to read calibration coefficients\n"); + return ret; + } + } + + /* + * Attempt to grab an optional EOC IRQ - only the BMP085 has this + * however as it happens, the BMP085 shares the chip ID of BMP180 + * so we look for an IRQ if we have that. + */ + if (irq > 0 && (chip_id == BMP180_CHIP_ID)) { + ret = bmp085_fetch_eoc_irq(dev, name, irq, data); + if (ret) + return ret; + } + + /* Enable runtime PM */ + pm_runtime_get_noresume(dev); + pm_runtime_set_active(dev); + pm_runtime_enable(dev); + /* + * Set autosuspend to two orders of magnitude larger than the + * start-up time. + */ + pm_runtime_set_autosuspend_delay(dev, data->start_up_time / 10); + pm_runtime_use_autosuspend(dev); + pm_runtime_put(dev); + + ret = devm_add_action_or_reset(dev, bmp280_pm_disable, dev); + if (ret) + return ret; + + return devm_iio_device_register(dev, indio_dev); +} +EXPORT_SYMBOL(bmp280_common_probe); + +#ifdef CONFIG_PM +static int bmp280_runtime_suspend(struct device *dev) +{ + struct iio_dev *indio_dev = dev_get_drvdata(dev); + struct bmp280_data *data = iio_priv(indio_dev); + + return regulator_bulk_disable(BMP280_NUM_SUPPLIES, data->supplies); +} + +static int bmp280_runtime_resume(struct device *dev) +{ + struct iio_dev *indio_dev = dev_get_drvdata(dev); + struct bmp280_data *data = iio_priv(indio_dev); + int ret; + + ret = regulator_bulk_enable(BMP280_NUM_SUPPLIES, data->supplies); + if (ret) + return ret; + usleep_range(data->start_up_time, data->start_up_time + 100); + return data->chip_info->chip_config(data); +} +#endif /* CONFIG_PM */ + +const struct dev_pm_ops bmp280_dev_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, + pm_runtime_force_resume) + SET_RUNTIME_PM_OPS(bmp280_runtime_suspend, + bmp280_runtime_resume, NULL) +}; +EXPORT_SYMBOL(bmp280_dev_pm_ops); + +MODULE_AUTHOR("Vlad Dogaru <vlad.dogaru@intel.com>"); +MODULE_DESCRIPTION("Driver for Bosch Sensortec BMP180/BMP280 pressure and temperature sensor"); +MODULE_LICENSE("GPL v2"); |