iio: imu: st_lsm6dsx: add i3c basic support for LSM6DSO and LSM6DSR

For today the st_lsm6dsx driver support LSM6DSO and LSM6DSR sensor only in
spi and i2c mode.

The LSM6DSO and LSM6DSR are also i3c capable so let's give i3c support to
them.

Signed-off-by: Vitor Soares <vitor.soares@synopsys.com>
Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/imu/st_lsm6dsx/Kconfig

@@ -2,11 +2,12 @@
 
 config IIO_ST_LSM6DSX
 	tristate "ST_LSM6DSx driver for STM 6-axis IMU MEMS sensors"
-	depends on (I2C || SPI)
+	depends on (I2C || SPI || I3C)
 	select IIO_BUFFER
 	select IIO_KFIFO_BUF
 	select IIO_ST_LSM6DSX_I2C if (I2C)
 	select IIO_ST_LSM6DSX_SPI if (SPI_MASTER)
+	select IIO_ST_LSM6DSX_I3C if (I3C)
 	help
 	  Say yes here to build support for STMicroelectronics LSM6DSx imu
 	  sensor. Supported devices: lsm6ds3, lsm6ds3h, lsm6dsl, lsm6dsm,
@@ -24,3 +25,8 @@ config IIO_ST_LSM6DSX_SPI
 	tristate
 	depends on IIO_ST_LSM6DSX
 	select REGMAP_SPI
+
+config IIO_ST_LSM6DSX_I3C
+	tristate
+	depends on IIO_ST_LSM6DSX
+	select REGMAP_I3C

drivers/iio/imu/st_lsm6dsx/Makefile

@@ -5,3 +5,4 @@ st_lsm6dsx-y := st_lsm6dsx_core.o st_lsm6dsx_buffer.o \
 obj-$(CONFIG_IIO_ST_LSM6DSX) += st_lsm6dsx.o
 obj-$(CONFIG_IIO_ST_LSM6DSX_I2C) += st_lsm6dsx_i2c.o
 obj-$(CONFIG_IIO_ST_LSM6DSX_SPI) += st_lsm6dsx_spi.o
+obj-$(CONFIG_IIO_ST_LSM6DSX_I3C) += st_lsm6dsx_i3c.o

drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_i3c.c

@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018 Synopsys, Inc. and/or its affiliates.
+ *
+ * Author: Vitor Soares <vitor.soares@synopsys.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/i3c/device.h>
+#include <linux/i3c/master.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/regmap.h>
+
+#include "st_lsm6dsx.h"
+
+static const struct i3c_device_id st_lsm6dsx_i3c_ids[] = {
+	I3C_DEVICE(0x0104, 0x006C, (void *)ST_LSM6DSO_ID),
+	I3C_DEVICE(0x0104, 0x006B, (void *)ST_LSM6DSR_ID),
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(i3c, st_lsm6dsx_i3c_ids);
+
+static int st_lsm6dsx_i3c_probe(struct i3c_device *i3cdev)
+{
+	struct regmap_config st_lsm6dsx_i3c_regmap_config = {
+		.reg_bits = 8,
+		.val_bits = 8,
+	};
+	const struct i3c_device_id *id = i3c_device_match_id(i3cdev,
+							    st_lsm6dsx_i3c_ids);
+	struct regmap *regmap;
+
+	regmap = devm_regmap_init_i3c(i3cdev, &st_lsm6dsx_i3c_regmap_config);
+	if (IS_ERR(regmap)) {
+		dev_err(&i3cdev->dev, "Failed to register i3c regmap %d\n",
+			(int)PTR_ERR(regmap));
+		return PTR_ERR(regmap);
+	}
+
+	return st_lsm6dsx_probe(&i3cdev->dev, 0, (uintptr_t)id->data, regmap);
+}
+
+static struct i3c_driver st_lsm6dsx_driver = {
+	.driver = {
+		.name = "st_lsm6dsx_i3c",
+		.pm = &st_lsm6dsx_pm_ops,
+	},
+	.probe = st_lsm6dsx_i3c_probe,
+	.id_table = st_lsm6dsx_i3c_ids,
+};
+module_i3c_driver(st_lsm6dsx_driver);
+
+MODULE_AUTHOR("Vitor Soares <vitor.soares@synopsys.com>");
+MODULE_DESCRIPTION("STMicroelectronics st_lsm6dsx i3c driver");
+MODULE_LICENSE("GPL v2");