On Du, 2019-01-27 at 18:30 -0200, Renato Lui Geh wrote:
Previously, the AD7780 driver only supported gpio for the 'powerdown'
pin. This commit adds suppport for the 'gain' and 'filter' pin.
Signed-off-by: Renato Lui Geh <renatogeh@xxxxxxxxx>
Signed-off-by: Giuliano Belinassi <giuliano.belinassi@xxxxxx>
Co-developed-by: Giuliano Belinassi <giuliano.belinassi@xxxxxx>
---
Changes in v2:
ÂÂÂÂÂÂÂÂ- Filter reading changed to mHz
ÂÂÂÂÂÂÂÂ- Storing filter, gain and voltage to chip_info
Hi,
Comments inline.
Regards,
Stefan
I would name this array ad778x_odr_avail or something like that.
Âdrivers/staging/iio/adc/ad7780.cÂÂÂÂÂÂÂ| 103 ++++++++++++++++++++++---
Âinclude/linux/iio/adc/ad_sigma_delta.h |ÂÂÂ5 ++
Â2 files changed, 99 insertions(+), 9 deletions(-)
diff --git a/drivers/staging/iio/adc/ad7780.c
b/drivers/staging/iio/adc/ad7780.c
index c4a85789c2db..82394e31b168 100644
--- a/drivers/staging/iio/adc/ad7780.c
+++ b/drivers/staging/iio/adc/ad7780.c
@@ -39,6 +39,15 @@
Â#define AD7170_PATTERNÂÂÂÂÂÂÂÂÂ(AD7780_PAT0 | AD7170_PAT2)
Â#define AD7170_PATTERN_MASKÂÂÂÂ(AD7780_PAT0 | AD7780_PAT1 | AD7170_PAT2)
+#define AD7780_GAIN_GPIOÂÂÂÂÂÂÂ0
+#define AD7780_FILTER_GPIOÂÂÂÂÂ1
+
+#define AD7780_GAIN_MIDPOINTÂÂÂ64
+#define AD7780_FILTER_MIDPOINT 13350
+
+static const unsigned int ad778x_gain[2]ÂÂÂÂ= { 1, 128 };
+static const unsigned int ad778x_filter[2]ÂÂ= { 10000, 16700 };
We should also consider adding the option to read the available
sampling frequencies from user space, but let's leave this for another
commit.
+
Âstruct ad7780_chip_info {
ÂÂÂÂÂÂÂÂstruct iio_chan_specÂÂÂÂchannel;
ÂÂÂÂÂÂÂÂunsigned intÂÂÂÂÂÂÂÂÂÂÂÂpattern_mask;
@@ -50,7 +59,11 @@ struct ad7780_state {
ÂÂÂÂÂÂÂÂconst struct ad7780_chip_infoÂÂÂ*chip_info;
ÂÂÂÂÂÂÂÂstruct regulatorÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ*reg;
ÂÂÂÂÂÂÂÂstruct gpio_descÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ*powerdown_gpio;
-ÂÂÂÂÂÂÂunsigned intÂÂÂÂgain;
+ÂÂÂÂÂÂÂstruct gpio_descÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ*gain_gpio;
+ÂÂÂÂÂÂÂstruct gpio_descÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ*filter_gpio;
+ÂÂÂÂÂÂÂunsigned intÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂgain;
+ÂÂÂÂÂÂÂunsigned intÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂfilter;
Also, this could be renamed as odr.
+ÂÂÂÂÂÂÂunsigned intÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂint_vref_mv;
ÂÂÂÂÂÂÂÂstruct ad_sigma_delta sd;
Â};
@@ -104,17 +117,65 @@ static int ad7780_read_raw(struct iio_dev
*indio_dev,
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂvoltage_uv = regulator_get_voltage(st->reg);
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂif (voltage_uv < 0)
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂreturn voltage_uv;
-ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ*val = (voltage_uv / 1000) * st->gain;
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂvoltage_uv /= 1000;
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ*val = voltage_uv * st->gain;
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ*val2 = chan->scan_type.realbits - 1;
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂst->int_vref_mv = voltage_uv;
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂreturn IIO_VAL_FRACTIONAL_LOG2;
ÂÂÂÂÂÂÂÂcase IIO_CHAN_INFO_OFFSET:
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ*val = -(1 << (chan->scan_type.realbits - 1));
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂreturn IIO_VAL_INT;
+ÂÂÂÂÂÂÂcase IIO_CHAN_INFO_SAMP_FREQ:
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ*val = st->filter;
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂreturn IIO_VAL_INT;
ÂÂÂÂÂÂÂÂ}
ÂÂÂÂÂÂÂÂreturn -EINVAL;
Â}
+static int ad7780_write_raw(struct iio_dev *indio_dev,
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂstruct iio_chan_spec const *chan,
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂint val,
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂint val2,
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂlong m)
+{
+ÂÂÂÂÂÂÂstruct ad7780_state *st = iio_priv(indio_dev);
+ÂÂÂÂÂÂÂconst struct ad7780_chip_info *chip_info = st->chip_info;
+ÂÂÂÂÂÂÂint vref, gain;
+ÂÂÂÂÂÂÂunsigned int full_scale;
+
+ÂÂÂÂÂÂÂif (!chip_info->is_ad778x)
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂreturn 0;
+
+ÂÂÂÂÂÂÂswitch (m) {
+ÂÂÂÂÂÂÂcase IIO_CHAN_INFO_SCALE:
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂif (val != 0)
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂreturn -EINVAL;
+
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂvref = st->int_vref_mv * 1000000LL;
From the datasheet, the VREF isÂÂ5 V, therefore your vref variable will
overflow. You probably needÂunsigned long long.
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂfull_scale = 1 << (chip_info->channel.scane_type.realbis
- 1);
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂgain = DIV_ROUND_CLOSEST(vref, full_scale);
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂgain = DIV_ROUND_CLOSEST(gain, val2);
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂst->gain = gain;
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂif (gain < AD7780_GAIN_MIDPOINT)
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂgain = 0;
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂelse
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂgain = 1;
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂgpiod_set_value(st->gain_gpio, gain);
+ÂÂÂÂÂÂÂbreak;
+ÂÂÂÂÂÂÂcase IIO_CHAN_INFO_SAMP_FREQ:
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂif (1000*val + val2/1000 < AD7780_FILTER_MIDPOINT)
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂval = 0;
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂelse
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂval = 1;
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂst->filter = ad778x_filter[val];
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂgpiod_set_value(st->filter_gpio, val);
+ÂÂÂÂÂÂÂbreak;
+ÂÂÂÂÂÂÂ}
+
+ÂÂÂÂÂÂÂreturn 0;
+}
+
Âstatic int ad7780_postprocess_sample(struct ad_sigma_delta *sigma_delta,
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂunsigned int raw_sample)
Â{
@@ -126,10 +187,8 @@ static int ad7780_postprocess_sample(struct
ad_sigma_delta *sigma_delta,
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂreturn -EIO;
ÂÂÂÂÂÂÂÂif (chip_info->is_ad778x) {
-ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂif (raw_sample & AD7780_GAIN)
-ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂst->gain = 1;
-ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂelse
-ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂst->gain = 128;
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂst->gain = ad778x_gain[raw_sample & AD7780_GAIN];
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂst->filter = ad778x_filter[raw_sample & AD7780_FILTER];
ÂÂÂÂÂÂÂÂ}
ÂÂÂÂÂÂÂÂreturn 0;
@@ -141,18 +200,20 @@ static const struct ad_sigma_delta_info
ad7780_sigma_delta_info = {
ÂÂÂÂÂÂÂÂ.has_registers = false,
Â};
-#define AD7780_CHANNEL(bits, wordsize) \
+#define AD7170_CHANNEL(bits, wordsize) \
ÂÂÂÂÂÂÂÂAD_SD_CHANNEL_NO_SAMP_FREQ(1, 0, 0, bits, 32, wordsize - bits)
+#define AD7780_CHANNEL(bits, wordsize) \
+ÂÂÂÂÂÂÂAD_SD_CHANNEL_GAIN_FILTER(1, 0, 0, bits, 32, wordsize - bits)
Âstatic const struct ad7780_chip_info ad7780_chip_info_tbl[] = {
ÂÂÂÂÂÂÂÂ[ID_AD7170] = {
-ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ.channel = AD7780_CHANNEL(12, 24),
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ.channel = AD7170_CHANNEL(12, 24),
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ.pattern = AD7170_PATTERN,
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ.pattern_mask = AD7170_PATTERN_MASK,
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ.is_ad778x = false,
ÂÂÂÂÂÂÂÂ},
ÂÂÂÂÂÂÂÂ[ID_AD7171] = {
-ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ.channel = AD7780_CHANNEL(16, 24),
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ.channel = AD7170_CHANNEL(16, 24),
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ.pattern = AD7170_PATTERN,
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ.pattern_mask = AD7170_PATTERN_MASK,
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ.is_ad778x = false,
@@ -173,6 +234,7 @@ static const struct ad7780_chip_info
ad7780_chip_info_tbl[] = {
Âstatic const struct iio_info ad7780_info = {
ÂÂÂÂÂÂÂÂ.read_raw = ad7780_read_raw,
+ÂÂÂÂÂÂÂ.write_raw = ad7780_write_raw,
Â};
Âstatic int ad7780_probe(struct spi_device *spi)
@@ -222,6 +284,29 @@ static int ad7780_probe(struct spi_device *spi)
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂgoto error_disable_reg;
ÂÂÂÂÂÂÂÂ}
+ÂÂÂÂÂÂÂif (st->chip_info->is_ad778x) {
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂst->gain_gpio = devm_gpiod_get_optional(&spi->dev,
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ"gain",
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂGPIOD_OUT_HIGH);
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂif (IS_ERR(st->gain_gpio)) {
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂret = PTR_ERR(st->gain_gpio);
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂdev_err(&spi->dev, "Failed to request gain GPIO:
%d\n",
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂret);
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂgoto error_disable_reg;
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ}
+
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂst->filter_gpio = devm_gpiod_get_optional(&spi->dev,
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ"filter",
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂGPIOD_OUT_HIGH)
;
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂif (IS_ERR(st->filter_gpio)) {
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂret = PTR_ERR(st->filter_gpio);
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂdev_err(&spi->dev,
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ"Failed to request filter GPIO: %d\n",
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂret);
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂgoto error_disable_reg;
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ}
+ÂÂÂÂÂÂÂ}
+
ÂÂÂÂÂÂÂÂret = ad_sd_setup_buffer_and_trigger(indio_dev);
ÂÂÂÂÂÂÂÂif (ret)
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂgoto error_disable_reg;
diff --git a/include/linux/iio/adc/ad_sigma_delta.h
b/include/linux/iio/adc/ad_sigma_delta.h
index 7e84351fa2c0..c01da869de83 100644
--- a/include/linux/iio/adc/ad_sigma_delta.h
+++ b/include/linux/iio/adc/ad_sigma_delta.h
@@ -176,6 +176,11 @@ int ad_sd_validate_trigger(struct iio_dev
*indio_dev, struct iio_trigger *trig);
ÂÂÂÂÂÂÂÂ__AD_SD_CHANNEL(_si, _channel, -1, _address, _bits, \
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ_storagebits, _shift, NULL, IIO_VOLTAGE, 0)
+#define AD_SD_CHANNEL_GAIN_FILTER(_si, _channel, _address, _bits, \
+ÂÂÂÂÂÂÂ_storagebits, _shift) \
+ÂÂÂÂÂÂÂ__AD_SD_CHANNEL(_si, _channel, -1, _address, _bits, \
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ_storagebits, _shift, NULL, IIO_VOLTAGE,
BIT(IIO_CHAN_INFO_RAW))
+
Do you need to define a new macro?
Â#define AD_SD_TEMP_CHANNEL(_si, _address, _bits, _storagebits, _shift) \
ÂÂÂÂÂÂÂÂ__AD_SD_CHANNEL(_si, 0, -1, _address, _bits, \
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ_storagebits, _shift, NULL, IIO_TEMP, \
--
2.20.1