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

79 lines
1.9 KiB
C

// 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);