From 62979904b0037430ecc7d8b682f684adced1340f Mon Sep 17 00:00:00 2001 From: Akinobu Mita Date: Sun, 24 Apr 2016 22:52:11 +0900 Subject: [PATCH] iio: pressure: bmp280: add ability to control oversampling rate This adds ability to control the oversampling ratio of the temperature and pressure measurement for both bmp180 and bmp280. Signed-off-by: Akinobu Mita Acked-by: Vlad Dogaru Cc: Christoph Mair Signed-off-by: Jonathan Cameron --- 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 dcf3b0ae2b87..2f1498e12bb2 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; -- 2.30.2