staging: iio: ad7780: add gain & filter gpio support
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>hifive-unleashed-5.2
Renato Lui Geh
Jonathan Cameron
parent
caeffabc36
commit
9085daa4ab
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@ -39,6 +39,9 @@
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#define AD7170_PATTERN (AD7780_PAT0 | AD7170_PAT2)
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#define AD7170_PATTERN_MASK (AD7780_PAT0 | AD7780_PAT1 | AD7170_PAT2)
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#define AD7780_GAIN_MIDPOINT 64
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#define AD7780_FILTER_MIDPOINT 13350
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struct ad7780_chip_info {
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struct iio_chan_spec channel;
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unsigned int pattern_mask;
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@ -50,7 +53,10 @@ struct ad7780_state {
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const struct ad7780_chip_info *chip_info;
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struct regulator *reg;
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struct gpio_desc *powerdown_gpio;
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unsigned int gain;
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struct gpio_desc *gain_gpio;
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struct gpio_desc *filter_gpio;
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unsigned int gain;
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unsigned int int_vref_mv;
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struct ad_sigma_delta sd;
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};
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@ -104,8 +110,10 @@ static int ad7780_read_raw(struct iio_dev *indio_dev,
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voltage_uv = regulator_get_voltage(st->reg);
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if (voltage_uv < 0)
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return voltage_uv;
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*val = (voltage_uv / 1000) * st->gain;
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voltage_uv /= 1000;
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*val = voltage_uv * st->gain;
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*val2 = chan->scan_type.realbits - 1;
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st->int_vref_mv = voltage_uv;
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return IIO_VAL_FRACTIONAL_LOG2;
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case IIO_CHAN_INFO_OFFSET:
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*val = -(1 << (chan->scan_type.realbits - 1));
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@ -115,6 +123,50 @@ static int ad7780_read_raw(struct iio_dev *indio_dev,
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return -EINVAL;
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}
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static int ad7780_write_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int val,
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int val2,
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long m)
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{
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struct ad7780_state *st = iio_priv(indio_dev);
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const struct ad7780_chip_info *chip_info = st->chip_info;
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unsigned long long vref;
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unsigned int full_scale, gain;
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if (!chip_info->is_ad778x)
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return -EINVAL;
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switch (m) {
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case IIO_CHAN_INFO_SCALE:
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if (val != 0)
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return -EINVAL;
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vref = st->int_vref_mv * 1000000LL;
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full_scale = 1 << (chip_info->channel.scan_type.realbits - 1);
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gain = DIV_ROUND_CLOSEST_ULL(vref, full_scale);
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gain = DIV_ROUND_CLOSEST(gain, val2);
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st->gain = gain;
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if (gain < AD7780_GAIN_MIDPOINT)
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gain = 0;
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else
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gain = 1;
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gpiod_set_value(st->gain_gpio, gain);
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break;
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case IIO_CHAN_INFO_SAMP_FREQ:
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if (1000*val + val2/1000 < AD7780_FILTER_MIDPOINT)
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val = 0;
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else
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val = 1;
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gpiod_set_value(st->filter_gpio, val);
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break;
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default:
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break;
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}
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return 0;
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}
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static int ad7780_postprocess_sample(struct ad_sigma_delta *sigma_delta,
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unsigned int raw_sample)
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{
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@ -125,13 +177,6 @@ static int ad7780_postprocess_sample(struct ad_sigma_delta *sigma_delta,
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((raw_sample & chip_info->pattern_mask) != chip_info->pattern))
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return -EIO;
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if (chip_info->is_ad778x) {
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if (raw_sample & AD7780_GAIN)
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st->gain = 1;
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else
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st->gain = 128;
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}
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return 0;
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}
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@ -173,8 +218,47 @@ static const struct ad7780_chip_info ad7780_chip_info_tbl[] = {
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static const struct iio_info ad7780_info = {
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.read_raw = ad7780_read_raw,
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.write_raw = ad7780_write_raw,
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};
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static int ad7780_init_gpios(struct device *dev, struct ad7780_state *st)
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{
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int ret;
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st->powerdown_gpio = devm_gpiod_get_optional(dev,
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"powerdown",
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GPIOD_OUT_LOW);
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if (IS_ERR(st->powerdown_gpio)) {
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ret = PTR_ERR(st->powerdown_gpio);
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dev_err(dev, "Failed to request powerdown GPIO: %d\n", ret);
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return ret;
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}
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if (!st->chip_info->is_ad778x)
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return 0;
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st->gain_gpio = devm_gpiod_get_optional(dev,
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"adi,gain",
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GPIOD_OUT_HIGH);
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if (IS_ERR(st->gain_gpio)) {
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ret = PTR_ERR(st->gain_gpio);
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dev_err(dev, "Failed to request gain GPIO: %d\n", ret);
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return ret;
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}
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st->filter_gpio = devm_gpiod_get_optional(dev,
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"adi,filter",
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GPIOD_OUT_HIGH);
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if (IS_ERR(st->filter_gpio)) {
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ret = PTR_ERR(st->filter_gpio);
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dev_err(dev, "Failed to request filter GPIO: %d\n", ret);
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return ret;
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}
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return 0;
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}
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static int ad7780_probe(struct spi_device *spi)
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{
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struct ad7780_state *st;
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@ -212,15 +296,9 @@ static int ad7780_probe(struct spi_device *spi)
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indio_dev->num_channels = 1;
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indio_dev->info = &ad7780_info;
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st->powerdown_gpio = devm_gpiod_get_optional(&spi->dev,
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"powerdown",
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GPIOD_OUT_LOW);
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if (IS_ERR(st->powerdown_gpio)) {
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ret = PTR_ERR(st->powerdown_gpio);
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dev_err(&spi->dev, "Failed to request powerdown GPIO: %d\n",
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ret);
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goto error_disable_reg;
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}
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ret = ad7780_init_gpios(&spi->dev, st);
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if (ret)
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goto error_cleanup_buffer_and_trigger;
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ret = ad_sd_setup_buffer_and_trigger(indio_dev);
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if (ret)
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