[PATCH 2/4] iio: adc: sd modulator: add scale support

Olivier Moysan
2020-02-04T10:11:13Z

Add scale support to sigma delta modulator.

Signed-off-by: Olivier Moysan <olivier.moysan@st.com>
---
drivers/iio/adc/sd_adc_modulator.c | 108 ++++++++++++++++++++++++++---
1 file changed, 100 insertions(+), 8 deletions(-)

diff --git a/drivers/iio/adc/sd_adc_modulator.c b/drivers/iio/adc/sd_adc_modulator.c
index 560d8c7d9d86..a83f35832050 100644
--- a/drivers/iio/adc/sd_adc_modulator.c
+++ b/drivers/iio/adc/sd_adc_modulator.c
@@ -10,8 +10,7 @@
#include <linux/iio/triggered_buffer.h>
#include <linux/module.h>
#include <linux/of_device.h>
-
-static const struct iio_info iio_sd_mod_iio_info;
+#include <linux/regulator/consumer.h>

static const struct iio_chan_spec iio_sd_mod_ch = {
.type = IIO_VOLTAGE,
@@ -21,34 +20,126 @@ static const struct iio_chan_spec iio_sd_mod_ch = {
.realbits = 1,
.shift = 0,
},
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
+};
+
+static const struct iio_chan_spec iio_sd_mod_ch_ads = {
+ .type = IIO_VOLTAGE,
+ .indexed = 1,
+ .scan_type = {
+ .sign = 'u',
+ .realbits = 1,
+ .shift = 0,
+ },
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
+ .differential = 1,
+};
+
+struct iio_sd_mod_priv {
+ struct regulator *vref;
+ int vref_mv;
+};
+
+static int iio_sd_mod_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val,
+ int *val2, long mask)
+{
+ struct iio_sd_mod_priv *priv = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_SCALE:
+ *val = priv->vref_mv;
+ *val2 = chan->scan_type.realbits;
+ return IIO_VAL_INT;
+ }
+
+ return -EINVAL;
+}
+
+static const struct iio_info iio_sd_mod_iio_info = {
+ .read_raw = iio_sd_mod_read_raw,
};

static int iio_sd_mod_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
+ struct iio_sd_mod_priv *priv;
struct iio_dev *iio;
+ int ret;

- iio = devm_iio_device_alloc(dev, 0);
+ iio = devm_iio_device_alloc(dev, sizeof(*priv));
if (!iio)
return -ENOMEM;

+ iio->channels = (const struct iio_chan_spec *)
+ of_device_get_match_data(&pdev->dev);
+
+ priv = iio_priv(iio);
+
iio->dev.parent = dev;
iio->dev.of_node = dev->of_node;
iio->name = dev_name(dev);
iio->info = &iio_sd_mod_iio_info;
iio->modes = INDIO_BUFFER_HARDWARE;
-
iio->num_channels = 1;
- iio->channels = &iio_sd_mod_ch;

platform_set_drvdata(pdev, iio);

- return devm_iio_device_register(&pdev->dev, iio);
+ priv->vref = devm_regulator_get_optional(dev, "vref");
+ if (IS_ERR(priv->vref)) {
+ ret = PTR_ERR(priv->vref);
+ if (ret != -ENODEV) {
+ if (ret != -EPROBE_DEFER)
+ dev_err(dev, "vref get failed, %d\n", ret);
+ return ret;
+ }
+ }
+
+ if (!IS_ERR(priv->vref)) {
+ ret = regulator_enable(priv->vref);
+ if (ret < 0) {
+ dev_err(dev, "vref enable failed %d\n", ret);
+ return ret;
+ }
+
+ ret = regulator_get_voltage(priv->vref);
+ if (ret < 0) {
+ dev_err(dev, "vref get failed, %d\n", ret);
+ goto err_regulator_disable;
+ }
+
+ priv->vref_mv = ret / 1000;
+ dev_dbg(dev, "vref+=%dmV\n", priv->vref_mv);
+ }
+
+ ret = devm_iio_device_register(&pdev->dev, iio);
+ if (ret < 0) {
+ dev_err(dev, "Failed to register sd-modulator, %d\n", ret);
+ goto err_regulator_disable;
+ }
+
+ return 0;
+
+err_regulator_disable:
+ regulator_disable(priv->vref);
+
+ return ret;
+}
+
+static int iio_sd_mod_remove(struct platform_device *pdev)
+{
+ struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+ struct iio_sd_mod_priv *priv = iio_priv(indio_dev);
+
+ if (priv->vref)
+ return regulator_disable(priv->vref);
+
+ return 0;
}

static const struct of_device_id sd_adc_of_match[] = {
- { .compatible = "sd-modulator" },
- { .compatible = "ads1201" },
+ { .compatible = "sd-modulator", .data = &iio_sd_mod_ch },
+ { .compatible = "ads1201", .data = &iio_sd_mod_ch_ads },
{ }
};
MODULE_DEVICE_TABLE(of, sd_adc_of_match);
@@ -59,6 +150,7 @@ static struct platform_driver iio_sd_mod_adc = {
.of_match_table = of_match_ptr(sd_adc_of_match),
},
.probe = iio_sd_mod_probe,
+ .remove = iio_sd_mod_remove,
};

module_platform_driver(iio_sd_mod_adc);
--
2.17.1