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_controller *ctlr,
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(ctlr, 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