iio: adc: Add initial basic support for MAX22531 ADC

Signed-off-by: Abhinav Jain <[email protected]>

Author: psychild

drivers/iio/adc/Kconfig

@@ -1126,6 +1126,12 @@ config MAX1363
 	  To compile this driver as a module, choose M here: the module will be
 	  called max1363.
 
+config MAX22531
+        tristate "Analog Devices MAX22531 ADC Driver"
+        depends on SPI
+        help
+          Say yes here to build support for this driver.
+
 config MAX77541_ADC
 	tristate "Analog Devices MAX77541 ADC driver"
 	depends on MFD_MAX77541

drivers/iio/adc/Makefile

@@ -156,6 +156,7 @@ obj-$(CONFIG_MAX11205) += max11205.o
 obj-$(CONFIG_MAX11410) += max11410.o
 obj-$(CONFIG_MAX1241) += max1241.o
 obj-$(CONFIG_MAX1363) += max1363.o
+obj-$(CONFIG_MAX22531) += max22531.o
 obj-$(CONFIG_MAX77541_ADC) += max77541-adc.o
 obj-$(CONFIG_MAX9611) += max9611.o
 obj-$(CONFIG_MCP320X) += mcp320x.o

drivers/iio/adc/max22531.c

@@ -0,0 +1,85 @@
+#include <linux/module.h>
+#include <linux/spi/spi.h>
+#include <linux/iio/iio.h>
+
+enum max22531_id {
+	max22531,
+};
+
+struct max22531 {
+	struct spi_device *spi;
+	struct regulator *vref;
+};
+
+#define MAX22531_CHANNEL(ch)						\
+	{								\
+		.type = IIO_VOLTAGE,					\
+		.indexed = 1,						\
+		.channel = (ch),					\
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
+		.scan_index = ch,					\
+		.output = 0,						\
+	}
+
+static const struct iio_chan_spec max22531_channels[] = {
+	MAX22531_CHANNEL(0),
+	MAX22531_CHANNEL(1),
+	MAX22531_CHANNEL(2),
+	MAX22531_CHANNEL(3),
+	IIO_CHAN_SOFT_TIMESTAMP(2),
+};
+
+static const struct iio_info max22531_info = {
+};
+
+static int max22531_probe(struct spi_device *spi)
+{
+	pr_err("max22531: probe on\n");
+
+	struct max22531 *adc;
+	struct iio_dev *indio_dev;
+	const struct spi_device_id *id = spi_get_device_id(spi);
+
+	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
+	if (!indio_dev) {
+		pr_err("max22531: Failed to allocate memory for IIO device.\n");
+		return -ENOMEM;
+	}
+
+	adc = iio_priv(indio_dev);
+	adc->spi = spi;
+	
+	indio_dev->name = spi_get_device_id(spi)->name;
+	indio_dev->info = &max22531_info;
+	indio_dev->channels = max22531_channels;
+	indio_dev->num_channels = ARRAY_SIZE(max22531_channels);
+
+	return devm_iio_device_register(&spi->dev, indio_dev);
+}
+
+static const struct spi_device_id max22531_id[] = {
+	{ "max22531", max22531 },
+	{}
+};
+MODULE_DEVICE_TABLE(spi, max22531_id);
+
+static const struct of_device_id max22531_dt_ids[] = {
+	{ .compatible = "maxim,max22531" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, max22531_dt_ids);
+
+static struct spi_driver max22531_driver = {
+	.driver = {
+		.name = "max22531",
+		.of_match_table = max22531_dt_ids,
+	},
+	.probe = max22531_probe,
+	.id_table = max22531_id,
+};
+module_spi_driver(max22531_driver);
+
+MODULE_AUTHOR("Abhinav Jain <[email protected]>");
+MODULE_DESCRIPTION("MAX22531 ADC");
+MODULE_LICENSE("GPL v2");