iio: gyro: fxas21002c: add spi driver

Add driver to talk over spi to a fxas21002c gyroscope device and use
the core as main controller.

Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/gyro/Kconfig

@@ -78,7 +78,8 @@ config FXAS21002C
        select IIO_BUFFER
        select IIO_TRIGGERED_BUFFER
        select FXAS21002C_I2C if (I2C)
-       depends on I2C
+       select FXAS21002C_SPI if (SPI)
+       depends on (I2C || SPI_MASTER)
        help
          Say yes here to build support for NXP FXAS21002C Tri-axis Gyro
          Sensor driver connected via I2C or SPI.
@@ -90,6 +91,10 @@ config FXAS21002C_I2C
        tristate
        select REGMAP_I2C
 
+config FXAS21002C_SPI
+       tristate
+       select REGMAP_SPI
+
 config HID_SENSOR_GYRO_3D
 	depends on HID_SENSOR_HUB
 	select IIO_BUFFER

drivers/iio/gyro/Makefile

@@ -14,6 +14,7 @@ obj-$(CONFIG_BMG160_I2C) += bmg160_i2c.o
 obj-$(CONFIG_BMG160_SPI) += bmg160_spi.o
 obj-$(CONFIG_FXAS21002C) += fxas21002c_core.o
 obj-$(CONFIG_FXAS21002C_I2C) += fxas21002c_i2c.o
+obj-$(CONFIG_FXAS21002C_SPI) += fxas21002c_spi.o
 
 obj-$(CONFIG_HID_SENSOR_GYRO_3D) += hid-sensor-gyro-3d.o
 

drivers/iio/gyro/fxas21002c_spi.c

@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for NXP Fxas21002c Gyroscope - SPI
+ *
+ * Copyright (C) 2019 Linaro Ltd.
+ */
+
+#include <linux/err.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/spi/spi.h>
+
+#include "fxas21002c.h"
+
+static const struct regmap_config fxas21002c_regmap_spi_conf = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = FXAS21002C_REG_CTRL3,
+};
+
+static int fxas21002c_spi_probe(struct spi_device *spi)
+{
+	const struct spi_device_id *id = spi_get_device_id(spi);
+	struct regmap *regmap;
+
+	regmap = devm_regmap_init_spi(spi, &fxas21002c_regmap_spi_conf);
+	if (IS_ERR(regmap)) {
+		dev_err(&spi->dev, "Failed to register spi regmap: %ld\n",
+			PTR_ERR(regmap));
+		return PTR_ERR(regmap);
+	}
+
+	return fxas21002c_core_probe(&spi->dev, regmap, spi->irq, id->name);
+}
+
+static int fxas21002c_spi_remove(struct spi_device *spi)
+{
+	fxas21002c_core_remove(&spi->dev);
+
+	return 0;
+}
+
+static const struct spi_device_id fxas21002c_spi_id[] = {
+	{ "fxas21002c", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, fxas21002c_spi_id);
+
+static const struct of_device_id fxas21002c_spi_of_match[] = {
+	{ .compatible = "nxp,fxas21002c", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, fxas21002c_spi_of_match);
+
+static struct spi_driver fxas21002c_spi_driver = {
+	.driver = {
+		.name = "fxas21002c_spi",
+		.pm = &fxas21002c_pm_ops,
+		.of_match_table = fxas21002c_spi_of_match,
+	},
+	.probe		= fxas21002c_spi_probe,
+	.remove		= fxas21002c_spi_remove,
+	.id_table	= fxas21002c_spi_id,
+};
+module_spi_driver(fxas21002c_spi_driver);
+
+MODULE_AUTHOR("Rui Miguel Silva <rui.silva@linaro.org>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("FXAS21002C SPI Gyro driver");