diff mbox series

[v2,6/6] iio: adc: ad7124: Implement system calibration

Message ID 5ee955a72e6f5226233053a883e8897ae325b568.1739902968.git.u.kleine-koenig@baylibre.com (mailing list archive)
State New
Headers show
Series iio: adc: ad{4130,7124,7173}: A few fixes and ad7124 calibration | expand

Commit Message

Uwe Kleine-König Feb. 18, 2025, 6:31 p.m. UTC
Allow triggering both zero-scale and full-scale calibration via sysfs in
the same way as it's done for ad7173.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
---
 drivers/iio/adc/ad7124.c | 141 ++++++++++++++++++++++++++++++++++-----
 1 file changed, 124 insertions(+), 17 deletions(-)

Comments

David Lechner Feb. 18, 2025, 7:37 p.m. UTC | #1
On 2/18/25 12:31 PM, Uwe Kleine-König wrote:
> Allow triggering both zero-scale and full-scale calibration via sysfs in
> the same way as it's done for ad7173.
> 
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
> ---

...

> +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);
> +	struct ad7124_channel *ch = &st->channels[chan->channel];
> +	struct device *dev = &st->sd.spi->dev;
> +	bool sys_calib;
> +	int ret, mode;
> +
> +	ret = kstrtobool(buf, &sys_calib);
> +	if (ret)
> +		return ret;
> +
> +	mode = ch->syscalib_mode;
> +	if (sys_calib) {

Could save some indent by inverting the if and doing early return.

> +		if (mode == AD7124_SYSCALIB_ZERO_SCALE) {

Probably should claim direct mode here to prevent calibration during
a buffered read or other operation (this seems to be missing from
other ad_sigma_delta driver calibrations functions as well).

> +			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 len;
> +}
> +
diff mbox series

Patch

diff --git a/drivers/iio/adc/ad7124.c b/drivers/iio/adc/ad7124.c
index 5c2e5a518af3..ad14503e9797 100644
--- a/drivers/iio/adc/ad7124.c
+++ b/drivers/iio/adc/ad7124.c
@@ -4,6 +4,9 @@ 
  *
  * Copyright 2018 Analog Devices Inc.
  */
+
+#define DEBUG
+
 #include <linux/bitfield.h>
 #include <linux/bitops.h>
 #include <linux/clk.h>
@@ -181,6 +184,7 @@  struct ad7124_channel {
 	struct ad7124_channel_config cfg;
 	unsigned int ain;
 	unsigned int slot;
+	u8 syscalib_mode;
 };
 
 struct ad7124_state {
@@ -202,23 +206,6 @@  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 +890,126 @@  static int ad7124_check_chip_id(struct ad7124_state *st)
 	return 0;
 }
 
+enum {
+	AD7124_SYSCALIB_ZERO_SCALE,
+	AD7124_SYSCALIB_FULL_SCALE,
+};
+
+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);
+	struct ad7124_channel *ch = &st->channels[chan->channel];
+	struct device *dev = &st->sd.spi->dev;
+	bool sys_calib;
+	int ret, mode;
+
+	ret = kstrtobool(buf, &sys_calib);
+	if (ret)
+		return ret;
+
+	mode = ch->syscalib_mode;
+	if (sys_calib) {
+		if (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 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