cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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v4l2-spi.c (1932B)

      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);