On Wed, 11 Aug 2021 18:18:02 -0300 Lucas Stankus <lucas.p.stankus@xxxxxxxxx> wrote: > ADXL313 is a small, thin, low power, 3-axis accelerometer with high > resolution measurement up to +/-4g. It includes an integrated 32-level > FIFO and has activity and inactivity sensing capabilities. > > Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/ADXL313.pdf > Signed-off-by: Lucas Stankus <lucas.p.stankus@xxxxxxxxx> > Reviewed-by: Alexandru Ardelean <ardeleanalex@xxxxxxxxx> Hi Lucas, I took another close look at this and I would like you to not use scan_index as you are here. It has a meaning tightly coupled to 'scans' which only exist as a concept once you have buffered mode. The preferred way to get channel specific values is to use addr and add a level of indirection (so a lookup structure of some type). A few more trivial things to add to what Andy raised inline below. Jonathan ... > +#endif /* _ADXL313_H_ */ > diff --git a/drivers/iio/accel/adxl313_core.c b/drivers/iio/accel/adxl313_core.c > new file mode 100644 > index 000000000000..8f3d4f5281c4 > --- /dev/null > +++ b/drivers/iio/accel/adxl313_core.c > @@ -0,0 +1,331 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * ADXL313 3-Axis Digital Accelerometer > + * > + * Copyright (c) 2021 Lucas Stankus <lucas.p.stankus@xxxxxxxxx> > + * > + * Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/ADXL313.pdf > + */ > + > +#include <linux/bitfield.h> > +#include <linux/iio/iio.h> > +#include <linux/module.h> > +#include <linux/regmap.h> > + > +#include "adxl313.h" > + > +const struct regmap_range adxl313_readable_reg_range[] = { > + regmap_reg_range(ADXL313_REG_DEVID0, ADXL313_REG_XID), > + regmap_reg_range(ADXL313_REG_SOFT_RESET, ADXL313_REG_SOFT_RESET), > + regmap_reg_range(ADXL313_REG_OFS_AXIS(0), ADXL313_REG_OFS_AXIS(2)), > + regmap_reg_range(ADXL313_REG_THRESH_ACT, ADXL313_REG_ACT_INACT_CTL), > + regmap_reg_range(ADXL313_REG_BW_RATE, ADXL313_REG_FIFO_STATUS) > +}; > + > +const struct regmap_access_table adxl313_readable_regs_table = { > + .yes_ranges = adxl313_readable_reg_range, > + .n_yes_ranges = ARRAY_SIZE(adxl313_readable_reg_range) > +}; > +EXPORT_SYMBOL_GPL(adxl313_readable_regs_table); > + > +const struct regmap_range adxl313_writable_reg_range[] = { > + regmap_reg_range(ADXL313_REG_SOFT_RESET, ADXL313_REG_SOFT_RESET), > + regmap_reg_range(ADXL313_REG_OFS_AXIS(0), ADXL313_REG_OFS_AXIS(2)), > + regmap_reg_range(ADXL313_REG_THRESH_ACT, ADXL313_REG_ACT_INACT_CTL), > + regmap_reg_range(ADXL313_REG_BW_RATE, ADXL313_REG_INT_MAP), > + regmap_reg_range(ADXL313_REG_DATA_FORMAT, ADXL313_REG_DATA_FORMAT), > + regmap_reg_range(ADXL313_REG_FIFO_CTL, ADXL313_REG_FIFO_CTL) > +}; > + > +const struct regmap_access_table adxl313_writable_regs_table = { > + .yes_ranges = adxl313_writable_reg_range, > + .n_yes_ranges = ARRAY_SIZE(adxl313_writable_reg_range) > +}; > +EXPORT_SYMBOL_GPL(adxl313_writable_regs_table); > + > +struct adxl313_data { > + struct regmap *regmap; > + struct mutex lock; /* lock to protect transf_buf */ > + __le16 transf_buf ____cacheline_aligned; > +}; > + > +static const int adxl313_odr_freqs[][2] = { > + [0] = { 6, 250000 }, > + [1] = { 12, 500000 }, > + [2] = { 25, 0 }, > + [3] = { 50, 0 }, > + [4] = { 100, 0 }, > + [5] = { 200, 0 }, > + [6] = { 400, 0 }, > + [7] = { 800, 0 }, > + [8] = { 1600, 0 }, > + [9] = { 3200, 0 }, > +}; > + > +#define ADXL313_ACCEL_CHANNEL(index, addr, axis) { \ > + .type = IIO_ACCEL, \ > + .address = addr, \ > + .modified = 1, \ > + .channel2 = IIO_MOD_##axis, \ > + .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), \ > + .info_mask_shared_by_type_available = \ > + BIT(IIO_CHAN_INFO_SAMP_FREQ), \ > + .scan_index = index, \ I'm not in general keen on seeing scan_index being set in a driver that isn't providing a buffer. Whilst some of the scan_type can have valid meaning without buffering, scan_index should not. The use you are making of it here, should use addr. So put a channel enum value into addr and use that to look up both the _raw address to read and anything else channel specific. That will give more consistent code than you currently have with a mixture of addr and scan_index being used depending on the particular thing being read about the channel. > + .scan_type = { \ > + .sign = 's', \ > + .realbits = 13, \ > + .storagebits = 16, \ > + .endianness = IIO_LE, \ sign, storagebits and endianness are things that are only likely to matter once buffered supported is added (where they relect the datalayout). For now please drop setting them at all. > + }, \ > +} > + > +static const struct iio_chan_spec adxl313_channels[] = { > + ADXL313_ACCEL_CHANNEL(0, ADXL313_REG_DATAX, X), > + ADXL313_ACCEL_CHANNEL(1, ADXL313_REG_DATAY, Y), > + ADXL313_ACCEL_CHANNEL(2, ADXL313_REG_DATAZ, Z), > +}; > + > +static int adxl313_set_odr(struct adxl313_data *data, > + unsigned int freq1, unsigned int freq2) > +{ > + unsigned int i; > + > + for (i = 0; i < ARRAY_SIZE(adxl313_odr_freqs); i++) { > + if (adxl313_odr_freqs[i][0] == freq1 && > + adxl313_odr_freqs[i][1] == freq2) > + break; > + } > + > + if (i == ARRAY_SIZE(adxl313_odr_freqs)) > + return -EINVAL; > + > + return regmap_update_bits(data->regmap, ADXL313_REG_BW_RATE, > + ADXL313_RATE_MSK, > + FIELD_PREP(ADXL313_RATE_MSK, > + ADXL313_RATE_BASE + i)); > +} > + > +static int adxl313_read_axis(struct adxl313_data *data, > + struct iio_chan_spec const *chan) > +{ > + int ret; > + > + mutex_lock(&data->lock); > + > + ret = regmap_bulk_read(data->regmap, > + chan->address, > + &data->transf_buf, 2); sizeof(data->trasf_buf) > + if (ret) > + goto unlock_ret; > + > + ret = le16_to_cpu(data->transf_buf); > + > +unlock_ret: > + mutex_unlock(&data->lock); > + return ret; > +} > + > +static int adxl313_read_freq_avail(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + const int **vals, int *type, int *length, > + long mask) > +{ > + switch (mask) { > + case IIO_CHAN_INFO_SAMP_FREQ: > + *vals = (const int *)adxl313_odr_freqs; > + *length = ARRAY_SIZE(adxl313_odr_freqs) * 2; > + *type = IIO_VAL_INT_PLUS_MICRO; > + return IIO_AVAIL_LIST; > + default: > + return -EINVAL; > + } > +} > + > +static int adxl313_read_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int *val, int *val2, long mask) > +{ > + struct adxl313_data *data = iio_priv(indio_dev); > + unsigned int regval; > + int ret; > + > + switch (mask) { > + case IIO_CHAN_INFO_RAW: > + ret = adxl313_read_axis(data, chan); > + if (ret < 0) > + return ret; > + > + *val = sign_extend32(ret, chan->scan_type.realbits - 1); > + return IIO_VAL_INT; > + case IIO_CHAN_INFO_SCALE: > + /* > + * Scale for any g range is given in datasheet as > + * 1024 LSB/g = 0.0009765625 * 9.80665 = 0.009576806640625 m/s^2 > + */ > + *val = 0; > + *val2 = 9576806; > + return IIO_VAL_INT_PLUS_NANO; > + case IIO_CHAN_INFO_CALIBBIAS: > + ret = regmap_read(data->regmap, > + ADXL313_REG_OFS_AXIS(chan->scan_index), As mentioned above, don't use scan_index for this purpose. There is no particular reason the scan_index for a given channel won't be changed in future as part of some layout optimization etc. addr is for this purpose and often contains an enum value to that gives a driver specific index of channels, then used to do things like you are doing here. > + ®val); > + if (ret) > + return ret; > + > + /* > + * 8-bit resolution at +/- 0.5g, that is 4x accel data scale > + * factor at full resolution > + */ > + *val = sign_extend32(regval, 7) * 4; > + return IIO_VAL_INT; > + case IIO_CHAN_INFO_SAMP_FREQ: > + ret = regmap_read(data->regmap, ADXL313_REG_BW_RATE, ®val); > + if (ret) > + return ret; > + > + ret = FIELD_GET(ADXL313_RATE_MSK, regval) - ADXL313_RATE_BASE; > + *val = adxl313_odr_freqs[ret][0]; > + *val2 = adxl313_odr_freqs[ret][1]; > + return IIO_VAL_INT_PLUS_MICRO; > + default: > + return -EINVAL; > + } > +} > + > +static int adxl313_write_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int val, int val2, long mask) > +{ > + struct adxl313_data *data = iio_priv(indio_dev); > + > + switch (mask) { > + case IIO_CHAN_INFO_CALIBBIAS: > + /* > + * 8-bit resolution at +/- 0.5g, that is 4x accel data scale > + * factor at full resolution > + */ > + if (clamp_val(val, -128 * 4, 127 * 4) != val) > + return -EINVAL; > + > + return regmap_write(data->regmap, > + ADXL313_REG_OFS_AXIS(chan->scan_index), > + val / 4); > + case IIO_CHAN_INFO_SAMP_FREQ: > + return adxl313_set_odr(data, val, val2); > + default: > + return -EINVAL; > + } > +} > + > +static const struct iio_info adxl313_info = { > + .read_raw = adxl313_read_raw, > + .write_raw = adxl313_write_raw, > + .read_avail = adxl313_read_freq_avail > +}; > + > +static int adxl313_setup(struct device *dev, struct adxl313_data *data, > + int (*interface_specific_setup)(struct device *, > + struct regmap *)) > +{ > + unsigned int regval; > + int ret; > + > + /* Ensures the device is in a consistent state after start up */ > + ret = regmap_write(data->regmap, ADXL313_REG_SOFT_RESET, > + ADXL313_SOFT_RESET); > + if (ret) > + return ret; > + > + if (interface_specific_setup) { > + ret = interface_specific_setup(dev, data->regmap); > + if (ret) > + return ret; > + } > + > + ret = regmap_read(data->regmap, ADXL313_REG_DEVID0, ®val); > + if (ret) > + return ret; > + > + if (regval != ADXL313_DEVID0) { > + dev_err(dev, "Invalid manufacturer ID: 0x%02x\n", regval); > + return -ENODEV; > + } > + > + ret = regmap_read(data->regmap, ADXL313_REG_DEVID1, ®val); > + if (ret) > + return ret; > + > + if (regval != ADXL313_DEVID1) { > + dev_err(dev, "Invalid mems ID: 0x%02x\n", regval); > + return -ENODEV; > + } > + > + ret = regmap_read(data->regmap, ADXL313_REG_PARTID, ®val); > + if (ret) > + return ret; > + > + if (regval != ADXL313_PARTID) { > + dev_err(dev, "Invalid device ID: 0x%02x\n", regval); > + return -ENODEV; > + } > + > + /* Sets the range to +/- 4g */ > + ret = regmap_update_bits(data->regmap, ADXL313_REG_DATA_FORMAT, > + ADXL313_RANGE_MSK, > + FIELD_PREP(ADXL313_RANGE_MSK, > + ADXL313_RANGE_4G)); > + if (ret) > + return ret; > + > + /* Enables full resolution */ > + ret = regmap_update_bits(data->regmap, ADXL313_REG_DATA_FORMAT, > + ADXL313_FULL_RES, ADXL313_FULL_RES); > + if (ret) > + return ret; > + > + /* Enables measurement mode */ > + return regmap_update_bits(data->regmap, ADXL313_REG_POWER_CTL, > + ADXL313_POWER_CTL_MSK, > + ADXL313_MEASUREMENT_MODE); > +} > + > +int adxl313_core_probe(struct device *dev, > + struct regmap *regmap, > + const char *name, > + int (*interface_specific_setup)(struct device *, > + struct regmap *)) > +{ > + struct adxl313_data *data; > + struct iio_dev *indio_dev; > + int ret; > + > + indio_dev = devm_iio_device_alloc(dev, sizeof(*data)); > + if (!indio_dev) > + return -ENOMEM; > + > + data = iio_priv(indio_dev); > + data->regmap = regmap; > + mutex_init(&data->lock); > + > + indio_dev->name = name; > + indio_dev->info = &adxl313_info; > + indio_dev->modes = INDIO_DIRECT_MODE; > + indio_dev->channels = adxl313_channels; > + indio_dev->num_channels = ARRAY_SIZE(adxl313_channels); > + > + ret = adxl313_setup(dev, data, interface_specific_setup); > + if (ret) { > + dev_err(dev, "ADXL313 setup failed\n"); > + return ret; > + } > + > + return devm_iio_device_register(dev, indio_dev); > +} > +EXPORT_SYMBOL_GPL(adxl313_core_probe); > + > +MODULE_AUTHOR("Lucas Stankus <lucas.p.stankus@xxxxxxxxx>"); > +MODULE_DESCRIPTION("ADXL313 3-Axis Digital Accelerometer core driver"); > +MODULE_LICENSE("GPL v2"); > diff --git a/drivers/iio/accel/adxl313_spi.c b/drivers/iio/accel/adxl313_spi.c > new file mode 100644 > index 000000000000..4d625b1753a5 > --- /dev/null > +++ b/drivers/iio/accel/adxl313_spi.c > @@ -0,0 +1,91 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * ADXL313 3-Axis Digital Accelerometer > + * > + * Copyright (c) 2021 Lucas Stankus <lucas.p.stankus@xxxxxxxxx> > + * > + * Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/ADXL313.pdf > + */ > + > +#include <linux/module.h> > +#include <linux/regmap.h> > +#include <linux/spi/spi.h> Seeing as you are going to be doing a v4, please add explicit includes for mod_devicetable.h which contains the of_device_id struct definition. Same for the i2c driver. > + > +#include "adxl313.h" > + ...
