diff options
Diffstat (limited to 'drivers/iio/accel/adxl345_core.c')
| -rw-r--r-- | drivers/iio/accel/adxl345_core.c | 140 |
1 files changed, 127 insertions, 13 deletions
diff --git a/drivers/iio/accel/adxl345_core.c b/drivers/iio/accel/adxl345_core.c index 7251d0e63d74..780f87f72338 100644 --- a/drivers/iio/accel/adxl345_core.c +++ b/drivers/iio/accel/adxl345_core.c @@ -6,21 +6,35 @@ * This file is subject to the terms and conditions of version 2 of * the GNU General Public License. See the file COPYING in the main * directory of this archive for more details. + * + * Datasheet: http://www.analog.com/media/en/technical-documentation/data-sheets/ADXL345.pdf */ #include <linux/module.h> #include <linux/regmap.h> #include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> #include "adxl345.h" #define ADXL345_REG_DEVID 0x00 +#define ADXL345_REG_OFSX 0x1e +#define ADXL345_REG_OFSY 0x1f +#define ADXL345_REG_OFSZ 0x20 +#define ADXL345_REG_OFS_AXIS(index) (ADXL345_REG_OFSX + (index)) +#define ADXL345_REG_BW_RATE 0x2C #define ADXL345_REG_POWER_CTL 0x2D #define ADXL345_REG_DATA_FORMAT 0x31 #define ADXL345_REG_DATAX0 0x32 #define ADXL345_REG_DATAY0 0x34 #define ADXL345_REG_DATAZ0 0x36 +#define ADXL345_REG_DATA_AXIS(index) \ + (ADXL345_REG_DATAX0 + (index) * sizeof(__le16)) + +#define ADXL345_BW_RATE GENMASK(3, 0) +#define ADXL345_BASE_RATE_NANO_HZ 97656250LL +#define NHZ_PER_HZ 1000000000LL #define ADXL345_POWER_CTL_MEASURE BIT(3) #define ADXL345_POWER_CTL_STANDBY 0x00 @@ -42,24 +56,33 @@ */ static const int adxl345_uscale = 38300; +/* + * The Datasheet lists a resolution of Resolution is ~49 mg per LSB. That's + * ~480mm/s**2 per LSB. + */ +static const int adxl375_uscale = 480000; + struct adxl345_data { struct regmap *regmap; u8 data_range; + enum adxl345_device_type type; }; -#define ADXL345_CHANNEL(reg, axis) { \ +#define ADXL345_CHANNEL(index, axis) { \ .type = IIO_ACCEL, \ .modified = 1, \ .channel2 = IIO_MOD_##axis, \ - .address = reg, \ - .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ - .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ + .address = index, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ + BIT(IIO_CHAN_INFO_CALIBBIAS), \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \ + BIT(IIO_CHAN_INFO_SAMP_FREQ), \ } static const struct iio_chan_spec adxl345_channels[] = { - ADXL345_CHANNEL(ADXL345_REG_DATAX0, X), - ADXL345_CHANNEL(ADXL345_REG_DATAY0, Y), - ADXL345_CHANNEL(ADXL345_REG_DATAZ0, Z), + ADXL345_CHANNEL(0, X), + ADXL345_CHANNEL(1, Y), + ADXL345_CHANNEL(2, Z), }; static int adxl345_read_raw(struct iio_dev *indio_dev, @@ -67,7 +90,9 @@ static int adxl345_read_raw(struct iio_dev *indio_dev, int *val, int *val2, long mask) { struct adxl345_data *data = iio_priv(indio_dev); - __le16 regval; + __le16 accel; + long long samp_freq_nhz; + unsigned int regval; int ret; switch (mask) { @@ -77,29 +102,117 @@ static int adxl345_read_raw(struct iio_dev *indio_dev, * ADXL345_REG_DATA(X0/Y0/Z0) contain the least significant byte * and ADXL345_REG_DATA(X0/Y0/Z0) + 1 the most significant byte */ - ret = regmap_bulk_read(data->regmap, chan->address, ®val, - sizeof(regval)); + ret = regmap_bulk_read(data->regmap, + ADXL345_REG_DATA_AXIS(chan->address), + &accel, sizeof(accel)); if (ret < 0) return ret; - *val = sign_extend32(le16_to_cpu(regval), 12); + *val = sign_extend32(le16_to_cpu(accel), 12); return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: *val = 0; - *val2 = adxl345_uscale; + switch (data->type) { + case ADXL345: + *val2 = adxl345_uscale; + break; + case ADXL375: + *val2 = adxl375_uscale; + break; + } return IIO_VAL_INT_PLUS_MICRO; + case IIO_CHAN_INFO_CALIBBIAS: + ret = regmap_read(data->regmap, + ADXL345_REG_OFS_AXIS(chan->address), ®val); + if (ret < 0) + return ret; + /* + * 8-bit resolution at +/- 2g, that is 4x accel data scale + * factor + */ + *val = sign_extend32(regval, 7) * 4; + + return IIO_VAL_INT; + case IIO_CHAN_INFO_SAMP_FREQ: + ret = regmap_read(data->regmap, ADXL345_REG_BW_RATE, ®val); + if (ret < 0) + return ret; + + samp_freq_nhz = ADXL345_BASE_RATE_NANO_HZ << + (regval & ADXL345_BW_RATE); + *val = div_s64_rem(samp_freq_nhz, NHZ_PER_HZ, val2); + + return IIO_VAL_INT_PLUS_NANO; } return -EINVAL; } +static int adxl345_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + struct adxl345_data *data = iio_priv(indio_dev); + s64 n; + + switch (mask) { + case IIO_CHAN_INFO_CALIBBIAS: + /* + * 8-bit resolution at +/- 2g, that is 4x accel data scale + * factor + */ + return regmap_write(data->regmap, + ADXL345_REG_OFS_AXIS(chan->address), + val / 4); + case IIO_CHAN_INFO_SAMP_FREQ: + n = div_s64(val * NHZ_PER_HZ + val2, ADXL345_BASE_RATE_NANO_HZ); + + return regmap_update_bits(data->regmap, ADXL345_REG_BW_RATE, + ADXL345_BW_RATE, + clamp_val(ilog2(n), 0, + ADXL345_BW_RATE)); + } + + return -EINVAL; +} + +static int adxl345_write_raw_get_fmt(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + long mask) +{ + switch (mask) { + case IIO_CHAN_INFO_CALIBBIAS: + return IIO_VAL_INT; + case IIO_CHAN_INFO_SAMP_FREQ: + return IIO_VAL_INT_PLUS_NANO; + default: + return -EINVAL; + } +} + +static IIO_CONST_ATTR_SAMP_FREQ_AVAIL( +"0.09765625 0.1953125 0.390625 0.78125 1.5625 3.125 6.25 12.5 25 50 100 200 400 800 1600 3200" +); + +static struct attribute *adxl345_attrs[] = { + &iio_const_attr_sampling_frequency_available.dev_attr.attr, + NULL, +}; + +static const struct attribute_group adxl345_attrs_group = { + .attrs = adxl345_attrs, +}; + static const struct iio_info adxl345_info = { + .attrs = &adxl345_attrs_group, .read_raw = adxl345_read_raw, + .write_raw = adxl345_write_raw, + .write_raw_get_fmt = adxl345_write_raw_get_fmt, }; int adxl345_core_probe(struct device *dev, struct regmap *regmap, - const char *name) + enum adxl345_device_type type, const char *name) { struct adxl345_data *data; struct iio_dev *indio_dev; @@ -125,6 +238,7 @@ int adxl345_core_probe(struct device *dev, struct regmap *regmap, data = iio_priv(indio_dev); dev_set_drvdata(dev, indio_dev); data->regmap = regmap; + data->type = type; /* Enable full-resolution mode */ data->data_range = ADXL345_DATA_FORMAT_FULL_RES; |