Commit df1f2e14 authored by Uwe Kleine-König's avatar Uwe Kleine-König Committed by Jonathan Cameron
Browse files

iio: adc: ad7124: Implement system calibration 



Allow triggering both zero-scale and full-scale calibration via sysfs in
the same way as it's done for ad7173.

Signed-off-by: default avatarUwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://patch.msgid.link/20250303114659.1672695-18-u.kleine-koenig@baylibre.com


Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 47036a03

drivers/iio/adc/ad7124.c

+135 −17
Original line number Diff line number Diff line
@@ -181,6 +181,7 @@ struct ad7124_channel { 
	struct ad7124_channel_config cfg;

	unsigned int ain;

	unsigned int slot;

	u8 syscalib_mode;

};



struct ad7124_state {
@@ -202,23 +203,6 @@ struct ad7124_state { 
	DECLARE_KFIFO(live_cfgs_fifo, struct ad7124_channel_config *, AD7124_MAX_CONFIGS);

};



static const struct iio_chan_spec ad7124_channel_template = {

	.type = IIO_VOLTAGE,

	.indexed = 1,

	.differential = 1,

	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |

		BIT(IIO_CHAN_INFO_SCALE) |

		BIT(IIO_CHAN_INFO_OFFSET) |

		BIT(IIO_CHAN_INFO_SAMP_FREQ) |

		BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),

	.scan_type = {

		.sign = 'u',

		.realbits = 24,

		.storagebits = 32,

		.endianness = IIO_BE,

	},

};



static struct ad7124_chip_info ad7124_chip_info_tbl[] = {

	[ID_AD7124_4] = {

		.name = "ad7124-4",
@@ -903,6 +887,140 @@ static int ad7124_check_chip_id(struct ad7124_state *st) 
	return 0;

}



enum {

	AD7124_SYSCALIB_ZERO_SCALE,

	AD7124_SYSCALIB_FULL_SCALE,

};



static int ad7124_syscalib_locked(struct ad7124_state *st, const struct iio_chan_spec *chan)

{

	struct device *dev = &st->sd.spi->dev;

	struct ad7124_channel *ch = &st->channels[chan->channel];

	int ret;



	if (ch->syscalib_mode == AD7124_SYSCALIB_ZERO_SCALE) {

		ch->cfg.calibration_offset = 0x800000;



		ret = ad_sd_calibrate(&st->sd, AD7124_MODE_CAL_SYS_ZERO,

				      chan->address);

		if (ret < 0)

			return ret;



		ret = ad_sd_read_reg(&st->sd, AD7124_OFFSET(ch->cfg.cfg_slot), 3,

				     &ch->cfg.calibration_offset);

		if (ret < 0)

			return ret;



		dev_dbg(dev, "offset for channel %d after zero-scale calibration: 0x%x\n",

			chan->channel, ch->cfg.calibration_offset);

	} else {

		ch->cfg.calibration_gain = st->gain_default;



		ret = ad_sd_calibrate(&st->sd, AD7124_MODE_CAL_SYS_FULL,

				      chan->address);

		if (ret < 0)

			return ret;



		ret = ad_sd_read_reg(&st->sd, AD7124_GAIN(ch->cfg.cfg_slot), 3,

				     &ch->cfg.calibration_gain);

		if (ret < 0)

			return ret;



		dev_dbg(dev, "gain for channel %d after full-scale calibration: 0x%x\n",

			chan->channel, ch->cfg.calibration_gain);

	}



	return 0;

}



static ssize_t ad7124_write_syscalib(struct iio_dev *indio_dev,

				     uintptr_t private,

				     const struct iio_chan_spec *chan,

				     const char *buf, size_t len)

{

	struct ad7124_state *st = iio_priv(indio_dev);

	bool sys_calib;

	int ret;



	ret = kstrtobool(buf, &sys_calib);

	if (ret)

		return ret;



	if (!sys_calib)

		return len;



	if (!iio_device_claim_direct(indio_dev))

		return -EBUSY;



	ret = ad7124_syscalib_locked(st, chan);



	iio_device_release_direct(indio_dev);



	return ret ?: len;

}



static const char * const ad7124_syscalib_modes[] = {

	[AD7124_SYSCALIB_ZERO_SCALE] = "zero_scale",

	[AD7124_SYSCALIB_FULL_SCALE] = "full_scale",

};



static int ad7124_set_syscalib_mode(struct iio_dev *indio_dev,

				    const struct iio_chan_spec *chan,

				    unsigned int mode)

{

	struct ad7124_state *st = iio_priv(indio_dev);



	st->channels[chan->channel].syscalib_mode = mode;



	return 0;

}



static int ad7124_get_syscalib_mode(struct iio_dev *indio_dev,

				    const struct iio_chan_spec *chan)

{

	struct ad7124_state *st = iio_priv(indio_dev);



	return st->channels[chan->channel].syscalib_mode;

}



static const struct iio_enum ad7124_syscalib_mode_enum = {

	.items = ad7124_syscalib_modes,

	.num_items = ARRAY_SIZE(ad7124_syscalib_modes),

	.set = ad7124_set_syscalib_mode,

	.get = ad7124_get_syscalib_mode

};



static const struct iio_chan_spec_ext_info ad7124_calibsys_ext_info[] = {

	{

		.name = "sys_calibration",

		.write = ad7124_write_syscalib,

		.shared = IIO_SEPARATE,

	},

	IIO_ENUM("sys_calibration_mode", IIO_SEPARATE,

		 &ad7124_syscalib_mode_enum),

	IIO_ENUM_AVAILABLE("sys_calibration_mode", IIO_SHARED_BY_TYPE,

			   &ad7124_syscalib_mode_enum),

	{ }

};



static const struct iio_chan_spec ad7124_channel_template = {

	.type = IIO_VOLTAGE,

	.indexed = 1,

	.differential = 1,

	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |

		BIT(IIO_CHAN_INFO_SCALE) |

		BIT(IIO_CHAN_INFO_OFFSET) |

		BIT(IIO_CHAN_INFO_SAMP_FREQ) |

		BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),

	.scan_type = {

		.sign = 'u',

		.realbits = 24,

		.storagebits = 32,

		.endianness = IIO_BE,

	},

	.ext_info = ad7124_calibsys_ext_info,

};



/*

 * Input specifiers 8 - 15 are explicitly reserved for ad7124-4

 * while they are fine for ad7124-8. Values above 31 don't fit