1 files changed, 78 insertions, 0 deletions
diff --git a/drivers/media/v4l2-core/v4l2-spi.c b/drivers/media/v4l2-core/v4l2-spi.c
new file mode 100644
index 000000000000..eadecdff7349
--- /dev/null
+++ b/drivers/media/v4l2-core/v4l2-spi.c
@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * v4l2-spi - SPI helpers for Video4Linux2
+ */
+
+#include <linux/module.h>
+#include <linux/spi/spi.h>
+#include <media/v4l2-common.h>
+#include <media/v4l2-device.h>
+
+void v4l2_spi_subdev_unregister(struct v4l2_subdev *sd)
+{
+	struct spi_device *spi = v4l2_get_subdevdata(sd);
+
+	if (spi && !spi->dev.of_node && !spi->dev.fwnode)
+		spi_unregister_device(spi);
+}
+
+void v4l2_spi_subdev_init(struct v4l2_subdev *sd, struct spi_device *spi,
+			  const struct v4l2_subdev_ops *ops)
+{
+	v4l2_subdev_init(sd, ops);
+	sd->flags |= V4L2_SUBDEV_FL_IS_SPI;
+	/* the owner is the same as the spi_device's driver owner */
+	sd->owner = spi->dev.driver->owner;
+	sd->dev = &spi->dev;
+	/* spi_device and v4l2_subdev point to one another */
+	v4l2_set_subdevdata(sd, spi);
+	spi_set_drvdata(spi, sd);
+	/* initialize name */
+	snprintf(sd->name, sizeof(sd->name), "%s %s",
+		 spi->dev.driver->name, dev_name(&spi->dev));
+}
+EXPORT_SYMBOL_GPL(v4l2_spi_subdev_init);
+
+struct v4l2_subdev *v4l2_spi_new_subdev(struct v4l2_device *v4l2_dev,
+					struct spi_master *master,
+					struct spi_board_info *info)
+{
+	struct v4l2_subdev *sd = NULL;
+	struct spi_device *spi = NULL;
+
+	if (!v4l2_dev)
+		return NULL;
+	if (info->modalias[0])
+		request_module(info->modalias);
+
+	spi = spi_new_device(master, info);
+
+	if (!spi || !spi->dev.driver)
+		goto error;
+
+	if (!try_module_get(spi->dev.driver->owner))
+		goto error;
+
+	sd = spi_get_drvdata(spi);
+
+	/*
+	 * Register with the v4l2_device which increases the module's
+	 * use count as well.
+	 */
+	if (v4l2_device_register_subdev(v4l2_dev, sd))
+		sd = NULL;
+
+	/* Decrease the module use count to match the first try_module_get. */
+	module_put(spi->dev.driver->owner);
+
+error:
+	/*
+	 * If we have a client but no subdev, then something went wrong and
+	 * we must unregister the client.
+	 */
+	if (!sd)
+		spi_unregister_device(spi);
+
+	return sd;
+}
+EXPORT_SYMBOL_GPL(v4l2_spi_new_subdev);