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staging: iio: ad7780: add gain & filter gpio support

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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@gmail.com>
Signed-off-by: Giuliano Belinassi <giuliano.belinassi@usp.br>
Co-developed-by: Giuliano Belinassi <giuliano.belinassi@usp.br>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Renato Lui Geh 2019-03-15 23:12:27 -03:00 committed by Jonathan Cameron
parent caeffabc36
commit 9085daa4ab
1 changed files with 96 additions and 18 deletions
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112
drivers/staging/iio/adc/ad7780.c
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@ -39,6 +39,9 @@
#define AD7170_PATTERN (AD7780_PAT0 | AD7170_PAT2)
#define AD7170_PATTERN_MASK (AD7780_PAT0 | AD7780_PAT1 | AD7170_PAT2)
#define AD7780_GAIN_MIDPOINT 64
#define AD7780_FILTER_MIDPOINT 13350
struct ad7780_chip_info {
struct iio_chan_spec channel;
unsigned int pattern_mask;
@ -50,7 +53,10 @@ struct ad7780_state {
const struct ad7780_chip_info *chip_info;
struct regulator *reg;
struct gpio_desc *powerdown_gpio;
struct gpio_desc *gain_gpio;
struct gpio_desc *filter_gpio;
unsigned int gain;
unsigned int int_vref_mv;
struct ad_sigma_delta sd;
};
@ -104,8 +110,10 @@ static int ad7780_read_raw(struct iio_dev *indio_dev,
voltage_uv = regulator_get_voltage(st->reg);
if (voltage_uv < 0)
return voltage_uv;
*val = (voltage_uv / 1000) * st->gain;
voltage_uv /= 1000;
*val = voltage_uv * st->gain;
*val2 = chan->scan_type.realbits - 1;
st->int_vref_mv = voltage_uv;
return IIO_VAL_FRACTIONAL_LOG2;
case IIO_CHAN_INFO_OFFSET:
*val = -(1 << (chan->scan_type.realbits - 1));
@ -115,6 +123,50 @@ static int ad7780_read_raw(struct iio_dev *indio_dev,
return -EINVAL;
}
static int ad7780_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val,
int val2,
long m)
{
struct ad7780_state *st = iio_priv(indio_dev);
const struct ad7780_chip_info *chip_info = st->chip_info;
unsigned long long vref;
unsigned int full_scale, gain;
if (!chip_info->is_ad778x)
return -EINVAL;
switch (m) {
case IIO_CHAN_INFO_SCALE:
if (val != 0)
return -EINVAL;
vref = st->int_vref_mv * 1000000LL;
full_scale = 1 << (chip_info->channel.scan_type.realbits - 1);
gain = DIV_ROUND_CLOSEST_ULL(vref, full_scale);
gain = DIV_ROUND_CLOSEST(gain, val2);
st->gain = gain;
if (gain < AD7780_GAIN_MIDPOINT)
gain = 0;
else
gain = 1;
gpiod_set_value(st->gain_gpio, gain);
break;
case IIO_CHAN_INFO_SAMP_FREQ:
if (1000*val + val2/1000 < AD7780_FILTER_MIDPOINT)
val = 0;
else
val = 1;
gpiod_set_value(st->filter_gpio, val);
break;
default:
break;
}
return 0;
}
static int ad7780_postprocess_sample(struct ad_sigma_delta *sigma_delta,
unsigned int raw_sample)
{
@ -125,13 +177,6 @@ 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 (raw_sample & AD7780_GAIN)
st->gain = 1;
else
st->gain = 128;
}
return 0;
}
@ -173,8 +218,47 @@ static const struct ad7780_chip_info ad7780_chip_info_tbl[] = {
static const struct iio_info ad7780_info = {
.read_raw = ad7780_read_raw,
.write_raw = ad7780_write_raw,
};
static int ad7780_init_gpios(struct device *dev, struct ad7780_state *st)
{
int ret;
st->powerdown_gpio = devm_gpiod_get_optional(dev,
"powerdown",
GPIOD_OUT_LOW);
if (IS_ERR(st->powerdown_gpio)) {
ret = PTR_ERR(st->powerdown_gpio);
dev_err(dev, "Failed to request powerdown GPIO: %d\n", ret);
return ret;
}
if (!st->chip_info->is_ad778x)
return 0;
st->gain_gpio = devm_gpiod_get_optional(dev,
"adi,gain",
GPIOD_OUT_HIGH);
if (IS_ERR(st->gain_gpio)) {
ret = PTR_ERR(st->gain_gpio);
dev_err(dev, "Failed to request gain GPIO: %d\n", ret);
return ret;
}
st->filter_gpio = devm_gpiod_get_optional(dev,
"adi,filter",
GPIOD_OUT_HIGH);
if (IS_ERR(st->filter_gpio)) {
ret = PTR_ERR(st->filter_gpio);
dev_err(dev, "Failed to request filter GPIO: %d\n", ret);
return ret;
}
return 0;
}
static int ad7780_probe(struct spi_device *spi)
{
struct ad7780_state *st;
@ -212,15 +296,9 @@ static int ad7780_probe(struct spi_device *spi)
indio_dev->num_channels = 1;
indio_dev->info = &ad7780_info;
st->powerdown_gpio = devm_gpiod_get_optional(&spi->dev,
"powerdown",
GPIOD_OUT_LOW);
if (IS_ERR(st->powerdown_gpio)) {
ret = PTR_ERR(st->powerdown_gpio);
dev_err(&spi->dev, "Failed to request powerdown GPIO: %d\n",
ret);
goto error_disable_reg;
}
ret = ad7780_init_gpios(&spi->dev, st);
if (ret)
goto error_cleanup_buffer_and_trigger;
ret = ad_sd_setup_buffer_and_trigger(indio_dev);
if (ret)