[PATCH v4 3/5] iio: adc: ad7380: do not store osr in private data structure

Julien Stephan
2025-01-08T12:49:47Z

Since regmap cache is now enabled, we don't need to store the
oversampling ratio in the private data structure.

Reviewed-by: David Lechner <dlechner@baylibre.com>
Signed-off-by: Julien Stephan <jstephan@baylibre.com>
---
drivers/iio/adc/ad7380.c | 79 +++++++++++++++++++++++++++++++++++++++---------
1 file changed, 65 insertions(+), 14 deletions(-)

diff --git a/drivers/iio/adc/ad7380.c b/drivers/iio/adc/ad7380.c
index b97d2978289e92ad502cd6a67de43d2b51cdab56..a532de4422082df8503454d66fc49f75b52cff68 100644
--- a/drivers/iio/adc/ad7380.c
+++ b/drivers/iio/adc/ad7380.c
@@ -582,7 +582,6 @@ struct ad7380_state {
const struct ad7380_chip_info *chip_info;
struct spi_device *spi;
struct regmap *regmap;
- unsigned int oversampling_ratio;
bool resolution_boost_enabled;
unsigned int ch;
bool seq;
@@ -710,6 +709,36 @@ static int ad7380_debugfs_reg_access(struct iio_dev *indio_dev, u32 reg,
return ret;
}

+/**
+ * ad7380_regval_to_osr - convert OSR register value to ratio
+ * @regval: register value to check
+ *
+ * Returns: the ratio corresponding to the OSR register. If regval is not in
+ * bound, return 1 (oversampling disabled)
+ *
+ */
+static int ad7380_regval_to_osr(unsigned int regval)
+{
+ if (regval >= ARRAY_SIZE(ad7380_oversampling_ratios))
+ return 1;
+
+ return ad7380_oversampling_ratios[regval];
+}
+
+static int ad7380_get_osr(struct ad7380_state *st, int *val)
+{
+ u32 tmp;
+ int ret;
+
+ ret = regmap_read(st->regmap, AD7380_REG_ADDR_CONFIG1, &tmp);
+ if (ret)
+ return ret;
+
+ *val = ad7380_regval_to_osr(FIELD_GET(AD7380_CONFIG1_OSR, tmp));
+
+ return 0;
+}
+
/*
* When switching channel, the ADC require an additional settling time.
* According to the datasheet, data is value on the third CS low. We already
@@ -725,11 +754,15 @@ static int ad7380_set_ch(struct ad7380_state *st, unsigned int ch)
.unit = SPI_DELAY_UNIT_NSECS,
}
};
- int ret;
+ int oversampling_ratio, ret;

if (st->ch == ch)
return 0;

+ ret = ad7380_get_osr(st, &oversampling_ratio);
+ if (ret)
+ return ret;
+
ret = regmap_update_bits(st->regmap,
AD7380_REG_ADDR_CONFIG1,
AD7380_CONFIG1_CH,
@@ -740,9 +773,9 @@ static int ad7380_set_ch(struct ad7380_state *st, unsigned int ch)

st->ch = ch;

- if (st->oversampling_ratio > 1)
+ if (oversampling_ratio > 1)
xfer.delay.value = T_CONVERT_0_NS +
- T_CONVERT_X_NS * (st->oversampling_ratio - 1) *
+ T_CONVERT_X_NS * (oversampling_ratio - 1) *
st->chip_info->num_simult_channels / AD7380_NUM_SDO_LINES;

return spi_sync_transfer(st->spi, &xfer, 1);
@@ -753,20 +786,25 @@ static int ad7380_set_ch(struct ad7380_state *st, unsigned int ch)
* @st: device instance specific state
* @scan_type: current scan type
*/
-static void ad7380_update_xfers(struct ad7380_state *st,
+static int ad7380_update_xfers(struct ad7380_state *st,
const struct iio_scan_type *scan_type)
{
struct spi_transfer *xfer = st->seq ? st->seq_xfer : st->normal_xfer;
unsigned int t_convert = T_CONVERT_NS;
+ int oversampling_ratio, ret;

/*
* In the case of oversampling, conversion time is higher than in normal
* mode. Technically T_CONVERT_X_NS is lower for some chips, but we use
* the maximum value for simplicity for now.
*/
- if (st->oversampling_ratio > 1)
+ ret = ad7380_get_osr(st, &oversampling_ratio);
+ if (ret)
+ return ret;
+
+ if (oversampling_ratio > 1)
t_convert = T_CONVERT_0_NS + T_CONVERT_X_NS *
- (st->oversampling_ratio - 1) *
+ (oversampling_ratio - 1) *
st->chip_info->num_simult_channels / AD7380_NUM_SDO_LINES;

if (st->seq) {
@@ -779,7 +817,7 @@ static void ad7380_update_xfers(struct ad7380_state *st,
st->chip_info->num_simult_channels;
xfer[3].rx_buf = xfer[2].rx_buf + xfer[2].len;
/* Additional delay required here when oversampling is enabled */
- if (st->oversampling_ratio > 1)
+ if (oversampling_ratio > 1)
xfer[2].delay.value = t_convert;
else
xfer[2].delay.value = 0;
@@ -791,6 +829,8 @@ static void ad7380_update_xfers(struct ad7380_state *st,
xfer[1].len = BITS_TO_BYTES(scan_type->storagebits) *
st->chip_info->num_simult_channels;
}
+
+ return 0;
}

static int ad7380_triggered_buffer_preenable(struct iio_dev *indio_dev)
@@ -798,6 +838,7 @@ static int ad7380_triggered_buffer_preenable(struct iio_dev *indio_dev)
struct ad7380_state *st = iio_priv(indio_dev);
const struct iio_scan_type *scan_type;
struct spi_message *msg = &st->normal_msg;
+ int ret;

/*
* Currently, we always read all channels at the same time. The scan_type
@@ -809,7 +850,6 @@ static int ad7380_triggered_buffer_preenable(struct iio_dev *indio_dev)

if (st->chip_info->has_mux) {
unsigned int index;
- int ret;

/*
* Depending on the requested scan_mask and current state,
@@ -840,7 +880,9 @@ static int ad7380_triggered_buffer_preenable(struct iio_dev *indio_dev)

}

- ad7380_update_xfers(st, scan_type);
+ ret = ad7380_update_xfers(st, scan_type);
+ if (ret)
+ return ret;

return spi_optimize_message(st->spi, msg);
}
@@ -913,7 +955,9 @@ static int ad7380_read_direct(struct ad7380_state *st, unsigned int scan_index,
return ret;
}

- ad7380_update_xfers(st, scan_type);
+ ret = ad7380_update_xfers(st, scan_type);
+ if (ret)
+ return ret;

ret = spi_sync(st->spi, &st->normal_msg);
if (ret < 0)
@@ -991,7 +1035,16 @@ static int ad7380_read_raw(struct iio_dev *indio_dev,

return IIO_VAL_INT;
case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
- *val = st->oversampling_ratio;
+ ret = iio_device_claim_direct_mode(indio_dev);
+ if (ret)
+ return ret;
+
+ ret = ad7380_get_osr(st, val);
+
+ iio_device_release_direct_mode(indio_dev);
+
+ if (ret)
+ return ret;

return IIO_VAL_INT;
default:
@@ -1058,7 +1111,6 @@ static int ad7380_set_oversampling_ratio(struct ad7380_state *st, int val)
if (ret)
return ret;

- st->oversampling_ratio = val;
st->resolution_boost_enabled = boost;

/*
@@ -1134,7 +1186,6 @@ static int ad7380_init(struct ad7380_state *st, bool external_ref_en)
}

/* This is the default value after reset. */
- st->oversampling_ratio = 1;
st->ch = 0;
st->seq = false;

--
2.47.1