[PATCH v5 04/11] staging: iio: ad7780: add filter reading to ad778x

Renato Lui Geh
2019-03-16T02:13:49Z

This patch adds the new feature of reading the filter odr value for
ad778x chips. This value is stored in the chip's state struct whenever a
read or write call is performed on the chip's driver.

This feature requires sharing SAMP_FREQ. Since the ad717x does not have
a filter option, the driver only shares the relevant info mask for the
ad778x family.

Signed-off-by: Renato Lui Geh <renatogeh@gmail.com>
---
Changes in v4:
- As mentioned in the previous patch, this was originally as part of
the 'add gain & filter gpio support' patch
Changes in v5:
- Moved ad778x_odr_avail declaration from GPIO patch to this one

drivers/staging/iio/adc/ad7780.c | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/drivers/staging/iio/adc/ad7780.c b/drivers/staging/iio/adc/ad7780.c
index fbcc0d3345ca..8ff74427d975 100644
--- a/drivers/staging/iio/adc/ad7780.c
+++ b/drivers/staging/iio/adc/ad7780.c
@@ -42,7 +42,8 @@
#define AD7780_GAIN_MIDPOINT 64
#define AD7780_FILTER_MIDPOINT 13350

-static const unsigned int ad778x_gain[2] = { 1, 128 };
+static const unsigned int ad778x_gain[2] = { 1, 128 };
+static const unsigned int ad778x_odr_avail[2] = { 10000, 16700 };

struct ad7780_chip_info {
struct iio_chan_spec channel;
@@ -58,6 +59,7 @@ struct ad7780_state {
struct gpio_desc *gain_gpio;
struct gpio_desc *filter_gpio;
unsigned int gain;
+ unsigned int odr;
unsigned int int_vref_mv;

struct ad_sigma_delta sd;
@@ -120,6 +122,9 @@ static int ad7780_read_raw(struct iio_dev *indio_dev,
case IIO_CHAN_INFO_OFFSET:
*val = -(1 << (chan->scan_type.realbits - 1));
return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ *val = st->odr;
+ return IIO_VAL_INT;
default:
break;
}
@@ -162,6 +167,7 @@ static int ad7780_write_raw(struct iio_dev *indio_dev,
val = 0;
else
val = 1;
+ st->odr = ad778x_odr_avail[val];
gpiod_set_value(st->filter_gpio, val);
break;
default:
@@ -181,8 +187,10 @@ static int ad7780_postprocess_sample(struct ad_sigma_delta *sigma_delta,
((raw_sample & chip_info->pattern_mask) != chip_info->pattern))
return -EIO;

- if (chip_info->is_ad778x)
+ if (chip_info->is_ad778x) {
st->gain = ad778x_gain[raw_sample & AD7780_GAIN];
+ st->odr = ad778x_odr_avail[raw_sample & AD7780_FILTER];
+ }

return 0;
}
@@ -194,17 +202,19 @@ static const struct ad_sigma_delta_info ad7780_sigma_delta_info = {
};

#define AD7780_CHANNEL(bits, wordsize) \
+ AD_SD_CHANNEL(1, 0, 0, bits, 32, wordsize - bits)
+#define AD7170_CHANNEL(bits, wordsize) \
AD_SD_CHANNEL_NO_SAMP_FREQ(1, 0, 0, bits, 32, wordsize - bits)

static const struct ad7780_chip_info ad7780_chip_info_tbl[] = {
[ID_AD7170] = {
- .channel = AD7780_CHANNEL(12, 24),
+ .channel = AD7170_CHANNEL(12, 24),
.pattern = AD7170_PATTERN,
.pattern_mask = AD7170_PATTERN_MASK,
.is_ad778x = false,
},
[ID_AD7171] = {
- .channel = AD7780_CHANNEL(16, 24),
+ .channel = AD7170_CHANNEL(16, 24),
.pattern = AD7170_PATTERN,
.pattern_mask = AD7170_PATTERN_MASK,
.is_ad778x = false,
--
2.21.0