// 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_controller *ctlr,
                                        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(ctlr, 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->owner))
                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);