diff options
author | Max Krummenacher <max.krummenacher@toradex.com> | 2024-02-29 21:24:13 +0100 |
---|---|---|
committer | Max Krummenacher <max.krummenacher@toradex.com> | 2024-02-29 21:24:26 +0100 |
commit | 99e9ab88844a2a2e1c048264315eb0d72eb0bf88 (patch) | |
tree | 0d89b05b1816b8cac1be77ac9b3c297762502e67 /drivers/iio/afe/iio-rescale.c | |
parent | 756e3199ba82d68ba07e5acf555d13aaa1da3da1 (diff) | |
parent | d761b18f6bc83bce94251467e3c0974243318456 (diff) |
Merge remote-tracking branch 'fslc/5.15-2.2.x-imx' into toradex_5.15-2.2.x-imx
Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
Conflicts:
drivers/gpu/drm/bridge/lontium-lt8912b.c
drivers/usb/dwc3/drd.c
Diffstat (limited to 'drivers/iio/afe/iio-rescale.c')
-rw-r--r-- | drivers/iio/afe/iio-rescale.c | 162 |
1 files changed, 123 insertions, 39 deletions
diff --git a/drivers/iio/afe/iio-rescale.c b/drivers/iio/afe/iio-rescale.c index cc28713b0dc8..ea0a39882eb2 100644 --- a/drivers/iio/afe/iio-rescale.c +++ b/drivers/iio/afe/iio-rescale.c @@ -3,43 +3,91 @@ * IIO rescale driver * * Copyright (C) 2018 Axentia Technologies AB + * Copyright (C) 2022 Liam Beguin <liambeguin@gmail.com> * * Author: Peter Rosin <peda@axentia.se> */ #include <linux/err.h> #include <linux/gcd.h> -#include <linux/iio/consumer.h> -#include <linux/iio/iio.h> #include <linux/module.h> #include <linux/of.h> #include <linux/of_device.h> #include <linux/platform_device.h> #include <linux/property.h> -struct rescale; +#include <linux/iio/afe/rescale.h> +#include <linux/iio/consumer.h> +#include <linux/iio/iio.h> -struct rescale_cfg { - enum iio_chan_type type; - int (*props)(struct device *dev, struct rescale *rescale); -}; +int rescale_process_scale(struct rescale *rescale, int scale_type, + int *val, int *val2) +{ + s64 tmp; -struct rescale { - const struct rescale_cfg *cfg; - struct iio_channel *source; - struct iio_chan_spec chan; - struct iio_chan_spec_ext_info *ext_info; - bool chan_processed; - s32 numerator; - s32 denominator; -}; + switch (scale_type) { + case IIO_VAL_FRACTIONAL: + *val *= rescale->numerator; + *val2 *= rescale->denominator; + return scale_type; + case IIO_VAL_INT: + *val *= rescale->numerator; + if (rescale->denominator == 1) + return scale_type; + *val2 = rescale->denominator; + return IIO_VAL_FRACTIONAL; + case IIO_VAL_FRACTIONAL_LOG2: + tmp = (s64)*val * 1000000000LL; + tmp = div_s64(tmp, rescale->denominator); + tmp *= rescale->numerator; + tmp = div_s64(tmp, 1000000000LL); + *val = tmp; + return scale_type; + default: + return -EOPNOTSUPP; + } +} + +int rescale_process_offset(struct rescale *rescale, int scale_type, + int scale, int scale2, int schan_off, + int *val, int *val2) +{ + s64 tmp, tmp2; + + switch (scale_type) { + case IIO_VAL_FRACTIONAL: + tmp = (s64)rescale->offset * scale2; + *val = div_s64(tmp, scale) + schan_off; + return IIO_VAL_INT; + case IIO_VAL_INT: + *val = div_s64(rescale->offset, scale) + schan_off; + return IIO_VAL_INT; + case IIO_VAL_FRACTIONAL_LOG2: + tmp = (s64)rescale->offset * (1 << scale2); + *val = div_s64(tmp, scale) + schan_off; + return IIO_VAL_INT; + case IIO_VAL_INT_PLUS_NANO: + tmp = (s64)rescale->offset * 1000000000LL; + tmp2 = ((s64)scale * 1000000000LL) + scale2; + *val = div64_s64(tmp, tmp2) + schan_off; + return IIO_VAL_INT; + case IIO_VAL_INT_PLUS_MICRO: + tmp = (s64)rescale->offset * 1000000LL; + tmp2 = ((s64)scale * 1000000LL) + scale2; + *val = div64_s64(tmp, tmp2) + schan_off; + return IIO_VAL_INT; + default: + return -EOPNOTSUPP; + } +} static int rescale_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { struct rescale *rescale = iio_priv(indio_dev); - s64 tmp; + int scale, scale2; + int schan_off = 0; int ret; switch (mask) { @@ -65,27 +113,58 @@ static int rescale_read_raw(struct iio_dev *indio_dev, } else { ret = iio_read_channel_scale(rescale->source, val, val2); } - switch (ret) { - case IIO_VAL_FRACTIONAL: - *val *= rescale->numerator; - *val2 *= rescale->denominator; - return ret; - case IIO_VAL_INT: - *val *= rescale->numerator; - if (rescale->denominator == 1) - return ret; - *val2 = rescale->denominator; - return IIO_VAL_FRACTIONAL; - case IIO_VAL_FRACTIONAL_LOG2: - tmp = (s64)*val * 1000000000LL; - tmp = div_s64(tmp, rescale->denominator); - tmp *= rescale->numerator; - tmp = div_s64(tmp, 1000000000LL); - *val = tmp; - return ret; - default: - return -EOPNOTSUPP; + return rescale_process_scale(rescale, ret, val, val2); + case IIO_CHAN_INFO_OFFSET: + /* + * Processed channels are scaled 1-to-1 and source offset is + * already taken into account. + * + * In other cases, real world measurement are expressed as: + * + * schan_scale * (raw + schan_offset) + * + * Given that the rescaler parameters are applied recursively: + * + * rescaler_scale * (schan_scale * (raw + schan_offset) + + * rescaler_offset) + * + * Or, + * + * (rescaler_scale * schan_scale) * (raw + + * (schan_offset + rescaler_offset / schan_scale) + * + * Thus, reusing the original expression the parameters exposed + * to userspace are: + * + * scale = schan_scale * rescaler_scale + * offset = schan_offset + rescaler_offset / schan_scale + */ + if (rescale->chan_processed) { + *val = rescale->offset; + return IIO_VAL_INT; + } + + if (iio_channel_has_info(rescale->source->channel, + IIO_CHAN_INFO_OFFSET)) { + ret = iio_read_channel_offset(rescale->source, + &schan_off, NULL); + if (ret != IIO_VAL_INT) + return ret < 0 ? ret : -EOPNOTSUPP; + } + + if (iio_channel_has_info(rescale->source->channel, + IIO_CHAN_INFO_SCALE)) { + ret = iio_read_channel_scale(rescale->source, &scale, &scale2); + return rescale_process_offset(rescale, ret, scale, scale2, + schan_off, val, val2); } + + /* + * If we get here we have no scale so scale 1:1 but apply + * rescaler and offset, if any. + */ + return rescale_process_offset(rescale, IIO_VAL_FRACTIONAL, 1, 1, + schan_off, val, val2); default: return -EINVAL; } @@ -149,8 +228,9 @@ static int rescale_configure_channel(struct device *dev, chan->type = rescale->cfg->type; if (iio_channel_has_info(schan, IIO_CHAN_INFO_RAW) && - iio_channel_has_info(schan, IIO_CHAN_INFO_SCALE)) { - dev_info(dev, "using raw+scale source channel\n"); + (iio_channel_has_info(schan, IIO_CHAN_INFO_SCALE) || + iio_channel_has_info(schan, IIO_CHAN_INFO_OFFSET))) { + dev_info(dev, "using raw+scale/offset source channel\n"); } else if (iio_channel_has_info(schan, IIO_CHAN_INFO_PROCESSED)) { dev_info(dev, "using processed channel\n"); rescale->chan_processed = true; @@ -162,6 +242,9 @@ static int rescale_configure_channel(struct device *dev, chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE); + if (rescale->offset) + chan->info_mask_separate |= BIT(IIO_CHAN_INFO_OFFSET); + /* * Using .read_avail() is fringe to begin with and makes no sense * whatsoever for processed channels, so we make sure that this cannot @@ -326,6 +409,7 @@ static int rescale_probe(struct platform_device *pdev) rescale->cfg = of_device_get_match_data(dev); rescale->numerator = 1; rescale->denominator = 1; + rescale->offset = 0; ret = rescale->cfg->props(dev, rescale); if (ret) |