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
v4l2_spi_subdev_unregister(struct v4l2_subdev * sd)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
v4l2_spi_subdev_init(struct v4l2_subdev * sd,struct spi_device * spi,const struct v4l2_subdev_ops * ops)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
v4l2_spi_new_subdev(struct v4l2_device * v4l2_dev,struct spi_master * master,struct spi_board_info * info)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);
79