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-rw-r--r--drivers/staging/iio/adc/ad7192.c149
1 files changed, 133 insertions, 16 deletions
diff --git a/drivers/staging/iio/adc/ad7192.c b/drivers/staging/iio/adc/ad7192.c
index 81ea2639c67c..e6b660489165 100644
--- a/drivers/staging/iio/adc/ad7192.c
+++ b/drivers/staging/iio/adc/ad7192.c
@@ -143,6 +143,10 @@
#define AD7192_EXT_FREQ_MHZ_MAX 5120000
#define AD7192_INT_FREQ_MHZ 4915200
+#define AD7192_NO_SYNC_FILTER 1
+#define AD7192_SYNC3_FILTER 3
+#define AD7192_SYNC4_FILTER 4
+
/* NOTE:
* The AD7190/2/5 features a dual use data out ready DOUT/RDY output.
* In order to avoid contentions on the SPI bus, it's therefore necessary
@@ -250,7 +254,7 @@ static int ad7192_of_clock_select(struct ad7192_state *st)
static int ad7192_setup(struct ad7192_state *st, struct device_node *np)
{
struct iio_dev *indio_dev = spi_get_drvdata(st->sd.spi);
- bool rej60_en, sinc3_en, refin2_en, chop_en;
+ bool rej60_en, refin2_en;
bool buf_en, bipolar, burnout_curr_en;
unsigned long long scale_uv;
int i, ret, id;
@@ -282,24 +286,12 @@ static int ad7192_setup(struct ad7192_state *st, struct device_node *np)
if (rej60_en)
st->mode |= AD7192_MODE_REJ60;
- sinc3_en = of_property_read_bool(np, "adi,sinc3-filter-enable");
- if (sinc3_en)
- st->mode |= AD7192_MODE_SINC3;
-
refin2_en = of_property_read_bool(np, "adi,refin2-pins-enable");
if (refin2_en && st->devid != ID_AD7195)
st->conf |= AD7192_CONF_REFSEL;
- chop_en = of_property_read_bool(np, "adi,chop-enable");
- if (chop_en) {
- st->conf |= AD7192_CONF_CHOP;
- if (sinc3_en)
- st->f_order = 3; /* SINC 3rd order */
- else
- st->f_order = 4; /* SINC 4th order */
- } else {
- st->f_order = 1;
- }
+ st->conf &= ~AD7192_CONF_CHOP;
+ st->f_order = AD7192_NO_SYNC_FILTER;
buf_en = of_property_read_bool(np, "adi,buffer-enable");
if (buf_en)
@@ -311,7 +303,7 @@ static int ad7192_setup(struct ad7192_state *st, struct device_node *np)
burnout_curr_en = of_property_read_bool(np,
"adi,burnout-currents-enable");
- if (burnout_curr_en && buf_en && !chop_en) {
+ if (burnout_curr_en && buf_en) {
st->conf |= AD7192_CONF_BURN;
} else if (burnout_curr_en) {
dev_warn(&st->sd.spi->dev,
@@ -409,6 +401,49 @@ static ssize_t ad7192_set(struct device *dev,
return ret ? ret : len;
}
+static void ad7192_get_available_filter_freq(struct ad7192_state *st,
+ int *freq)
+{
+ unsigned int fadc;
+
+ /* Formulas for filter at page 25 of the datasheet */
+ fadc = DIV_ROUND_CLOSEST(st->fclk,
+ AD7192_SYNC4_FILTER * AD7192_MODE_RATE(st->mode));
+ freq[0] = DIV_ROUND_CLOSEST(fadc * 240, 1024);
+
+ fadc = DIV_ROUND_CLOSEST(st->fclk,
+ AD7192_SYNC3_FILTER * AD7192_MODE_RATE(st->mode));
+ freq[1] = DIV_ROUND_CLOSEST(fadc * 240, 1024);
+
+ fadc = DIV_ROUND_CLOSEST(st->fclk, AD7192_MODE_RATE(st->mode));
+ freq[2] = DIV_ROUND_CLOSEST(fadc * 230, 1024);
+ freq[3] = DIV_ROUND_CLOSEST(fadc * 272, 1024);
+}
+
+static ssize_t ad7192_show_filter_avail(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct ad7192_state *st = iio_priv(indio_dev);
+ unsigned int freq_avail[4], i;
+ size_t len = 0;
+
+ ad7192_get_available_filter_freq(st, freq_avail);
+
+ for (i = 0; i < ARRAY_SIZE(freq_avail); i++)
+ len += scnprintf(buf + len, PAGE_SIZE - len,
+ "%d.%d ", freq_avail[i] / 1000,
+ freq_avail[i] % 1000);
+
+ buf[len - 1] = '\n';
+
+ return len;
+}
+
+static IIO_DEVICE_ATTR(filter_low_pass_3db_frequency_available,
+ 0444, ad7192_show_filter_avail, NULL, 0);
+
static IIO_DEVICE_ATTR(bridge_switch_en, 0644,
ad7192_show_bridge_switch, ad7192_set,
AD7192_REG_GPOCON);
@@ -418,6 +453,7 @@ static IIO_DEVICE_ATTR(ac_excitation_en, 0644,
AD7192_REG_MODE);
static struct attribute *ad7192_attributes[] = {
+ &iio_dev_attr_filter_low_pass_3db_frequency_available.dev_attr.attr,
&iio_dev_attr_bridge_switch_en.dev_attr.attr,
&iio_dev_attr_ac_excitation_en.dev_attr.attr,
NULL
@@ -428,6 +464,7 @@ static const struct attribute_group ad7192_attribute_group = {
};
static struct attribute *ad7195_attributes[] = {
+ &iio_dev_attr_filter_low_pass_3db_frequency_available.dev_attr.attr,
&iio_dev_attr_bridge_switch_en.dev_attr.attr,
NULL
};
@@ -441,6 +478,75 @@ static unsigned int ad7192_get_temp_scale(bool unipolar)
return unipolar ? 2815 * 2 : 2815;
}
+static int ad7192_set_3db_filter_freq(struct ad7192_state *st,
+ int val, int val2)
+{
+ int freq_avail[4], i, ret, freq;
+ unsigned int diff_new, diff_old;
+ int idx = 0;
+
+ diff_old = U32_MAX;
+ freq = val * 1000 + val2;
+
+ ad7192_get_available_filter_freq(st, freq_avail);
+
+ for (i = 0; i < ARRAY_SIZE(freq_avail); i++) {
+ diff_new = abs(freq - freq_avail[i]);
+ if (diff_new < diff_old) {
+ diff_old = diff_new;
+ idx = i;
+ }
+ }
+
+ switch (idx) {
+ case 0:
+ st->f_order = AD7192_SYNC4_FILTER;
+ st->mode &= ~AD7192_MODE_SINC3;
+
+ st->conf |= AD7192_CONF_CHOP;
+ break;
+ case 1:
+ st->f_order = AD7192_SYNC3_FILTER;
+ st->mode |= AD7192_MODE_SINC3;
+
+ st->conf |= AD7192_CONF_CHOP;
+ break;
+ case 2:
+ st->f_order = AD7192_NO_SYNC_FILTER;
+ st->mode &= ~AD7192_MODE_SINC3;
+
+ st->conf &= ~AD7192_CONF_CHOP;
+ break;
+ case 3:
+ st->f_order = AD7192_NO_SYNC_FILTER;
+ st->mode |= AD7192_MODE_SINC3;
+
+ st->conf &= ~AD7192_CONF_CHOP;
+ break;
+ }
+
+ ret = ad_sd_write_reg(&st->sd, AD7192_REG_MODE, 3, st->mode);
+ if (ret < 0)
+ return ret;
+
+ return ad_sd_write_reg(&st->sd, AD7192_REG_CONF, 3, st->conf);
+}
+
+static int ad7192_get_3db_filter_freq(struct ad7192_state *st)
+{
+ unsigned int fadc;
+
+ fadc = DIV_ROUND_CLOSEST(st->fclk,
+ st->f_order * AD7192_MODE_RATE(st->mode));
+
+ if (st->conf & AD7192_CONF_CHOP)
+ return DIV_ROUND_CLOSEST(fadc * 240, 1024);
+ if (st->mode & AD7192_MODE_SINC3)
+ return DIV_ROUND_CLOSEST(fadc * 272, 1024);
+ else
+ return DIV_ROUND_CLOSEST(fadc * 230, 1024);
+}
+
static int ad7192_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val,
@@ -481,6 +587,10 @@ static int ad7192_read_raw(struct iio_dev *indio_dev,
*val = st->fclk /
(st->f_order * 1024 * AD7192_MODE_RATE(st->mode));
return IIO_VAL_INT;
+ case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+ *val = ad7192_get_3db_filter_freq(st);
+ *val2 = 1000;
+ return IIO_VAL_FRACTIONAL;
}
return -EINVAL;
@@ -535,6 +645,9 @@ static int ad7192_write_raw(struct iio_dev *indio_dev,
st->mode |= AD7192_MODE_RATE(div);
ad_sd_write_reg(&st->sd, AD7192_REG_MODE, 3, st->mode);
break;
+ case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+ ret = ad7192_set_3db_filter_freq(st, val, val2 / 1000);
+ break;
default:
ret = -EINVAL;
}
@@ -553,6 +666,8 @@ static int ad7192_write_raw_get_fmt(struct iio_dev *indio_dev,
return IIO_VAL_INT_PLUS_NANO;
case IIO_CHAN_INFO_SAMP_FREQ:
return IIO_VAL_INT;
+ case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+ return IIO_VAL_INT_PLUS_MICRO;
default:
return -EINVAL;
}
@@ -653,6 +768,8 @@ static int ad7192_channels_config(struct iio_dev *indio_dev)
for (i = 0; i < indio_dev->num_channels; i++) {
*chan = channels[i];
+ chan->info_mask_shared_by_all |=
+ BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY);
if (chan->type != IIO_TEMP)
chan->info_mask_shared_by_type_available |=
BIT(IIO_CHAN_INFO_SCALE);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.