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
  11 void 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
  19 void 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 }
  34 EXPORT_SYMBOL_GPL(v4l2_spi_subdev_init);
  35
  36 struct 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
  68 error:
  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 }
  78 EXPORT_SYMBOL_GPL(v4l2_spi_new_subdev);