IIO: ADC: add sigma delta modulator support

Add generic driver to support sigma delta modulators.
Typically, this device is hardware connected to
an IIO device in charge of the conversion. Devices are
bonded through the hardware consumer API.

Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 68 insertions, 0 deletions

diff --git a/drivers/iio/adc/sd_adc_modulator.c b/drivers/iio/adc/sd_adc_modulator.c
new file mode 100644
index 000000000000..560d8c7d9d86
--- /dev/null
+++ b/drivers/iio/adc/sd_adc_modulator.c
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Generic sigma delta modulator driver
+ *
+ * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
+ * Author: Arnaud Pouliquen <arnaud.pouliquen@st.com>.
+ */
+
+#include <linux/iio/iio.h>
+#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;
+
+static const struct iio_chan_spec iio_sd_mod_ch = {
+	.type = IIO_VOLTAGE,
+	.indexed = 1,
+	.scan_type = {
+		.sign = 'u',
+		.realbits = 1,
+		.shift = 0,
+	},
+};
+
+static int iio_sd_mod_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct iio_dev *iio;
+
+	iio = devm_iio_device_alloc(dev, 0);
+	if (!iio)
+		return -ENOMEM;
+
+	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);
+}
+
+static const struct of_device_id sd_adc_of_match[] = {
+	{ .compatible = "sd-modulator" },
+	{ .compatible = "ads1201" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, sd_adc_of_match);
+
+static struct platform_driver iio_sd_mod_adc = {
+	.driver = {
+		.name = "iio_sd_adc_mod",
+		.of_match_table = of_match_ptr(sd_adc_of_match),
+	},
+	.probe = iio_sd_mod_probe,
+};
+
+module_platform_driver(iio_sd_mod_adc);
+
+MODULE_DESCRIPTION("Basic sigma delta modulator");
+MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@st.com>");
+MODULE_LICENSE("GPL v2");