1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * v4l2-i2c - I2C helpers for Video4Linux2
4 */
5
6#include <linux/i2c.h>
7#include <linux/module.h>
8#include <media/v4l2-common.h>
9#include <media/v4l2-device.h>
10
11void v4l2_i2c_subdev_unregister(struct v4l2_subdev *sd)
12{
13 struct i2c_client *client = v4l2_get_subdevdata(sd);
14
15 /*
16 * We need to unregister the i2c client
17 * explicitly. We cannot rely on
18 * i2c_del_adapter to always unregister
19 * clients for us, since if the i2c bus is a
20 * platform bus, then it is never deleted.
21 *
22 * Device tree or ACPI based devices must not
23 * be unregistered as they have not been
24 * registered by us, and would not be
25 * re-created by just probing the V4L2 driver.
26 */
27 if (client && !client->dev.of_node && !client->dev.fwnode)
28 i2c_unregister_device(client);
29}
30
31void v4l2_i2c_subdev_set_name(struct v4l2_subdev *sd,
32 struct i2c_client *client,
33 const char *devname, const char *postfix)
34{
35 if (!devname)
36 devname = client->dev.driver->name;
37 if (!postfix)
38 postfix = "";
39
40 snprintf(buf: sd->name, size: sizeof(sd->name), fmt: "%s%s %d-%04x", devname, postfix,
41 i2c_adapter_id(adap: client->adapter), client->addr);
42}
43EXPORT_SYMBOL_GPL(v4l2_i2c_subdev_set_name);
44
45void v4l2_i2c_subdev_init(struct v4l2_subdev *sd, struct i2c_client *client,
46 const struct v4l2_subdev_ops *ops)
47{
48 v4l2_subdev_init(sd, ops);
49 sd->flags |= V4L2_SUBDEV_FL_IS_I2C;
50 /* the owner is the same as the i2c_client's driver owner */
51 sd->owner = client->dev.driver->owner;
52 sd->dev = &client->dev;
53 /* i2c_client and v4l2_subdev point to one another */
54 v4l2_set_subdevdata(sd, p: client);
55 i2c_set_clientdata(client, data: sd);
56 v4l2_i2c_subdev_set_name(sd, client, NULL, NULL);
57}
58EXPORT_SYMBOL_GPL(v4l2_i2c_subdev_init);
59
60/* Load an i2c sub-device. */
61struct v4l2_subdev
62*v4l2_i2c_new_subdev_board(struct v4l2_device *v4l2_dev,
63 struct i2c_adapter *adapter,
64 struct i2c_board_info *info,
65 const unsigned short *probe_addrs)
66{
67 struct v4l2_subdev *sd = NULL;
68 struct i2c_client *client;
69
70 if (!v4l2_dev)
71 return NULL;
72
73 request_module(I2C_MODULE_PREFIX "%s", info->type);
74
75 /* Create the i2c client */
76 if (info->addr == 0 && probe_addrs)
77 client = i2c_new_scanned_device(adap: adapter, info, addr_list: probe_addrs,
78 NULL);
79 else
80 client = i2c_new_client_device(adap: adapter, info);
81
82 /*
83 * Note: by loading the module first we are certain that c->driver
84 * will be set if the driver was found. If the module was not loaded
85 * first, then the i2c core tries to delay-load the module for us,
86 * and then c->driver is still NULL until the module is finally
87 * loaded. This delay-load mechanism doesn't work if other drivers
88 * want to use the i2c device, so explicitly loading the module
89 * is the best alternative.
90 */
91 if (!i2c_client_has_driver(client))
92 goto error;
93
94 /* Lock the module so we can safely get the v4l2_subdev pointer */
95 if (!try_module_get(module: client->dev.driver->owner))
96 goto error;
97 sd = i2c_get_clientdata(client);
98
99 /*
100 * Register with the v4l2_device which increases the module's
101 * use count as well.
102 */
103 if (v4l2_device_register_subdev(v4l2_dev, sd))
104 sd = NULL;
105 /* Decrease the module use count to match the first try_module_get. */
106 module_put(module: client->dev.driver->owner);
107
108error:
109 /*
110 * If we have a client but no subdev, then something went wrong and
111 * we must unregister the client.
112 */
113 if (!IS_ERR(ptr: client) && !sd)
114 i2c_unregister_device(client);
115 return sd;
116}
117EXPORT_SYMBOL_GPL(v4l2_i2c_new_subdev_board);
118
119struct v4l2_subdev *v4l2_i2c_new_subdev(struct v4l2_device *v4l2_dev,
120 struct i2c_adapter *adapter,
121 const char *client_type,
122 u8 addr,
123 const unsigned short *probe_addrs)
124{
125 struct i2c_board_info info;
126
127 /*
128 * Setup the i2c board info with the device type and
129 * the device address.
130 */
131 memset(&info, 0, sizeof(info));
132 strscpy(info.type, client_type, sizeof(info.type));
133 info.addr = addr;
134
135 return v4l2_i2c_new_subdev_board(v4l2_dev, adapter, &info,
136 probe_addrs);
137}
138EXPORT_SYMBOL_GPL(v4l2_i2c_new_subdev);
139
140/* Return i2c client address of v4l2_subdev. */
141unsigned short v4l2_i2c_subdev_addr(struct v4l2_subdev *sd)
142{
143 struct i2c_client *client = v4l2_get_subdevdata(sd);
144
145 return client ? client->addr : I2C_CLIENT_END;
146}
147EXPORT_SYMBOL_GPL(v4l2_i2c_subdev_addr);
148
149/*
150 * Return a list of I2C tuner addresses to probe. Use only if the tuner
151 * addresses are unknown.
152 */
153const unsigned short *v4l2_i2c_tuner_addrs(enum v4l2_i2c_tuner_type type)
154{
155 static const unsigned short radio_addrs[] = {
156#if IS_ENABLED(CONFIG_MEDIA_TUNER_TEA5761)
157 0x10,
158#endif
159 0x60,
160 I2C_CLIENT_END
161 };
162 static const unsigned short demod_addrs[] = {
163 0x42, 0x43, 0x4a, 0x4b,
164 I2C_CLIENT_END
165 };
166 static const unsigned short tv_addrs[] = {
167 0x42, 0x43, 0x4a, 0x4b, /* tda8290 */
168 0x60, 0x61, 0x62, 0x63, 0x64,
169 I2C_CLIENT_END
170 };
171
172 switch (type) {
173 case ADDRS_RADIO:
174 return radio_addrs;
175 case ADDRS_DEMOD:
176 return demod_addrs;
177 case ADDRS_TV:
178 return tv_addrs;
179 case ADDRS_TV_WITH_DEMOD:
180 return tv_addrs + 4;
181 }
182 return NULL;
183}
184EXPORT_SYMBOL_GPL(v4l2_i2c_tuner_addrs);
185

source code of linux/drivers/media/v4l2-core/v4l2-i2c.c