LXR linux/drivers/media/v4l2-core/v4l2-spi.c

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * v4l2-spi - SPI helpers for Video4Linux2
   4 */
   5
   6#include <linux/module.h>
   7#include <linux/spi/spi.h>
   8#include <media/v4l2-common.h>
   9#include <media/v4l2-device.h>
  10
  11void v4l2_spi_subdev_unregister(struct v4l2_subdev *sd)
  12{
  13        struct spi_device *spi = v4l2_get_subdevdata(sd);
  14
  15        if (spi && !spi->dev.of_node && !spi->dev.fwnode)
  16                spi_unregister_device(spi);
  17}
  18
  19void v4l2_spi_subdev_init(struct v4l2_subdev *sd, struct spi_device *spi,
  20                          const struct v4l2_subdev_ops *ops)
  21{
  22        v4l2_subdev_init(sd, ops);
  23        sd->flags |= V4L2_SUBDEV_FL_IS_SPI;
  24        /* the owner is the same as the spi_device's driver owner */
  25        sd->owner = spi->dev.driver->owner;
  26        sd->dev = &spi->dev;
  27        /* spi_device and v4l2_subdev point to one another */
  28        v4l2_set_subdevdata(sd, spi);
  29        spi_set_drvdata(spi, sd);
  30        /* initialize name */
  31        snprintf(sd->name, sizeof(sd->name), "%s %s",
  32                 spi->dev.driver->name, dev_name(&spi->dev));
  33}
  34EXPORT_SYMBOL_GPL(v4l2_spi_subdev_init);
  35
  36struct v4l2_subdev *v4l2_spi_new_subdev(struct v4l2_device *v4l2_dev,
  37                                        struct spi_master *master,
  38                                        struct spi_board_info *info)
  39{
  40        struct v4l2_subdev *sd = NULL;
  41        struct spi_device *spi = NULL;
  42
  43        if (!v4l2_dev)
  44                return NULL;
  45        if (info->modalias[0])
  46                request_module(info->modalias);
  47
  48        spi = spi_new_device(master, info);
  49
  50        if (!spi || !spi->dev.driver)
  51                goto error;
  52
  53        if (!try_module_get(spi->dev.driver->owner))
  54                goto error;
  55
  56        sd = spi_get_drvdata(spi);
  57
  58        /*
  59         * Register with the v4l2_device which increases the module's
  60         * use count as well.
  61         */
  62        if (v4l2_device_register_subdev(v4l2_dev, sd))
  63                sd = NULL;
  64
  65        /* Decrease the module use count to match the first try_module_get. */
  66        module_put(spi->dev.driver->owner);
  67
  68error:
  69        /*
  70         * If we have a client but no subdev, then something went wrong and
  71         * we must unregister the client.
  72         */
  73        if (!sd)
  74                spi_unregister_device(spi);
  75
  76        return sd;
  77}
  78EXPORT_SYMBOL_GPL(v4l2_spi_new_subdev);
  79