1 files changed, 120 insertions, 0 deletions
diff --git a/drivers/iio/common/st_sensors/st_sensors_spi.c b/drivers/iio/common/st_sensors/st_sensors_spi.c
new file mode 100644
index 000000000..63e302c3f
--- /dev/null
+++ b/drivers/iio/common/st_sensors/st_sensors_spi.c
@@ -0,0 +1,120 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * STMicroelectronics sensors spi library driver
+ *
+ * Copyright 2012-2013 STMicroelectronics Inc.
+ *
+ * Denis Ciocca <denis.ciocca@st.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/iio/iio.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/spi/spi.h>
+
+#include <linux/iio/common/st_sensors_spi.h>
+
+#define ST_SENSORS_SPI_MULTIREAD	0xc0
+
+static const struct regmap_config st_sensors_spi_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+};
+
+static const struct regmap_config st_sensors_spi_regmap_multiread_bit_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.read_flag_mask = ST_SENSORS_SPI_MULTIREAD,
+};
+
+/*
+ * st_sensors_is_spi_3_wire() - check if SPI 3-wire mode has been selected
+ * @spi: spi device reference.
+ *
+ * Return: true if SPI 3-wire mode is selected, false otherwise.
+ */
+static bool st_sensors_is_spi_3_wire(struct spi_device *spi)
+{
+	struct st_sensors_platform_data *pdata;
+	struct device *dev = &spi->dev;
+
+	if (device_property_read_bool(dev, "spi-3wire"))
+		return true;
+
+	pdata = dev_get_platdata(dev);
+	if (pdata && pdata->spi_3wire)
+		return true;
+
+	return false;
+}
+
+/*
+ * st_sensors_configure_spi_3_wire() - configure SPI 3-wire if needed
+ * @spi: spi device reference.
+ * @settings: sensor specific settings reference.
+ *
+ * Return: 0 on success, else a negative error code.
+ */
+static int st_sensors_configure_spi_3_wire(struct spi_device *spi,
+					   struct st_sensor_settings *settings)
+{
+	if (settings->sim.addr) {
+		u8 buffer[] = {
+			settings->sim.addr,
+			settings->sim.value
+		};
+
+		return spi_write(spi, buffer, 2);
+	}
+
+	return 0;
+}
+
+/*
+ * st_sensors_spi_configure() - configure SPI interface
+ * @indio_dev: IIO device reference.
+ * @spi: spi device reference.
+ *
+ * Return: 0 on success, else a negative error code.
+ */
+int st_sensors_spi_configure(struct iio_dev *indio_dev,
+			     struct spi_device *spi)
+{
+	struct st_sensor_data *sdata = iio_priv(indio_dev);
+	const struct regmap_config *config;
+	int err;
+
+	if (st_sensors_is_spi_3_wire(spi)) {
+		err = st_sensors_configure_spi_3_wire(spi,
+						      sdata->sensor_settings);
+		if (err < 0)
+			return err;
+	}
+
+	if (sdata->sensor_settings->multi_read_bit)
+		config = &st_sensors_spi_regmap_multiread_bit_config;
+	else
+		config = &st_sensors_spi_regmap_config;
+
+	sdata->regmap = devm_regmap_init_spi(spi, config);
+	if (IS_ERR(sdata->regmap)) {
+		dev_err(&spi->dev, "Failed to register spi regmap (%ld)\n",
+			PTR_ERR(sdata->regmap));
+		return PTR_ERR(sdata->regmap);
+	}
+
+	spi_set_drvdata(spi, indio_dev);
+
+	indio_dev->name = spi->modalias;
+
+	sdata->irq = spi->irq;
+
+	return 0;
+}
+EXPORT_SYMBOL_NS(st_sensors_spi_configure, IIO_ST_SENSORS);
+
+MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
+MODULE_DESCRIPTION("STMicroelectronics ST-sensors spi driver");
+MODULE_LICENSE("GPL v2");