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 <linux/property.h>
9 #include <media/v4l2-common.h>
10 #include <media/v4l2-device.h>
11
v4l2_i2c_subdev_unregister(struct v4l2_subdev * sd)12 void v4l2_i2c_subdev_unregister(struct v4l2_subdev *sd)
13 {
14 struct i2c_client *client = v4l2_get_subdevdata(sd);
15
16 /*
17 * We need to unregister the i2c client
18 * explicitly. We cannot rely on
19 * i2c_del_adapter to always unregister
20 * clients for us, since if the i2c bus is a
21 * platform bus, then it is never deleted.
22 *
23 * Device tree or ACPI based devices must not
24 * be unregistered as they have not been
25 * registered by us, and would not be
26 * re-created by just probing the V4L2 driver.
27 */
28 if (client && !dev_fwnode(&client->dev))
29 i2c_unregister_device(client);
30 }
31
v4l2_i2c_subdev_set_name(struct v4l2_subdev * sd,struct i2c_client * client,const char * devname,const char * postfix)32 void v4l2_i2c_subdev_set_name(struct v4l2_subdev *sd,
33 struct i2c_client *client,
34 const char *devname, const char *postfix)
35 {
36 if (!devname)
37 devname = client->dev.driver->name;
38 if (!postfix)
39 postfix = "";
40
41 snprintf(sd->name, sizeof(sd->name), "%s%s %d-%04x", devname, postfix,
42 i2c_adapter_id(client->adapter), client->addr);
43 }
44 EXPORT_SYMBOL_GPL(v4l2_i2c_subdev_set_name);
45
v4l2_i2c_subdev_init(struct v4l2_subdev * sd,struct i2c_client * client,const struct v4l2_subdev_ops * ops)46 void v4l2_i2c_subdev_init(struct v4l2_subdev *sd, struct i2c_client *client,
47 const struct v4l2_subdev_ops *ops)
48 {
49 v4l2_subdev_init(sd, ops);
50 sd->flags |= V4L2_SUBDEV_FL_IS_I2C;
51 /* the owner is the same as the i2c_client's driver owner */
52 sd->owner = client->dev.driver->owner;
53 sd->dev = &client->dev;
54 /* i2c_client and v4l2_subdev point to one another */
55 v4l2_set_subdevdata(sd, client);
56 i2c_set_clientdata(client, sd);
57 v4l2_i2c_subdev_set_name(sd, client, NULL, NULL);
58 }
59 EXPORT_SYMBOL_GPL(v4l2_i2c_subdev_init);
60
61 /* Load an i2c sub-device. */
62 struct v4l2_subdev
v4l2_i2c_new_subdev_board(struct v4l2_device * v4l2_dev,struct i2c_adapter * adapter,struct i2c_board_info * info,const unsigned short * probe_addrs)63 *v4l2_i2c_new_subdev_board(struct v4l2_device *v4l2_dev,
64 struct i2c_adapter *adapter,
65 struct i2c_board_info *info,
66 const unsigned short *probe_addrs)
67 {
68 struct v4l2_subdev *sd = NULL;
69 struct i2c_client *client;
70
71 if (!v4l2_dev)
72 return NULL;
73
74 request_module(I2C_MODULE_PREFIX "%s", info->type);
75
76 /* Create the i2c client */
77 if (info->addr == 0 && probe_addrs)
78 client = i2c_new_scanned_device(adapter, info, probe_addrs,
79 NULL);
80 else
81 client = i2c_new_client_device(adapter, info);
82
83 /*
84 * Note: by loading the module first we are certain that c->driver
85 * will be set if the driver was found. If the module was not loaded
86 * first, then the i2c core tries to delay-load the module for us,
87 * and then c->driver is still NULL until the module is finally
88 * loaded. This delay-load mechanism doesn't work if other drivers
89 * want to use the i2c device, so explicitly loading the module
90 * is the best alternative.
91 */
92 if (!i2c_client_has_driver(client))
93 goto error;
94
95 /* Lock the module so we can safely get the v4l2_subdev pointer */
96 if (!try_module_get(client->dev.driver->owner))
97 goto error;
98 sd = i2c_get_clientdata(client);
99
100 /*
101 * Register with the v4l2_device which increases the module's
102 * use count as well.
103 */
104 if (__v4l2_device_register_subdev(v4l2_dev, sd, sd->owner))
105 sd = NULL;
106 /* Decrease the module use count to match the first try_module_get. */
107 module_put(client->dev.driver->owner);
108
109 error:
110 /*
111 * If we have a client but no subdev, then something went wrong and
112 * we must unregister the client.
113 */
114 if (!IS_ERR(client) && !sd)
115 i2c_unregister_device(client);
116 return sd;
117 }
118 EXPORT_SYMBOL_GPL(v4l2_i2c_new_subdev_board);
119
v4l2_i2c_new_subdev(struct v4l2_device * v4l2_dev,struct i2c_adapter * adapter,const char * client_type,u8 addr,const unsigned short * probe_addrs)120 struct v4l2_subdev *v4l2_i2c_new_subdev(struct v4l2_device *v4l2_dev,
121 struct i2c_adapter *adapter,
122 const char *client_type,
123 u8 addr,
124 const unsigned short *probe_addrs)
125 {
126 struct i2c_board_info info;
127
128 /*
129 * Setup the i2c board info with the device type and
130 * the device address.
131 */
132 memset(&info, 0, sizeof(info));
133 strscpy(info.type, client_type, sizeof(info.type));
134 info.addr = addr;
135
136 return v4l2_i2c_new_subdev_board(v4l2_dev, adapter, &info,
137 probe_addrs);
138 }
139 EXPORT_SYMBOL_GPL(v4l2_i2c_new_subdev);
140
141 /* Return i2c client address of v4l2_subdev. */
v4l2_i2c_subdev_addr(struct v4l2_subdev * sd)142 unsigned short v4l2_i2c_subdev_addr(struct v4l2_subdev *sd)
143 {
144 struct i2c_client *client = v4l2_get_subdevdata(sd);
145
146 return client ? client->addr : I2C_CLIENT_END;
147 }
148 EXPORT_SYMBOL_GPL(v4l2_i2c_subdev_addr);
149
150 /*
151 * Return a list of I2C tuner addresses to probe. Use only if the tuner
152 * addresses are unknown.
153 */
v4l2_i2c_tuner_addrs(enum v4l2_i2c_tuner_type type)154 const unsigned short *v4l2_i2c_tuner_addrs(enum v4l2_i2c_tuner_type type)
155 {
156 static const unsigned short radio_addrs[] = {
157 #if IS_ENABLED(CONFIG_MEDIA_TUNER_TEA5761)
158 0x10,
159 #endif
160 0x60,
161 I2C_CLIENT_END
162 };
163 static const unsigned short demod_addrs[] = {
164 0x42, 0x43, 0x4a, 0x4b,
165 I2C_CLIENT_END
166 };
167 static const unsigned short tv_addrs[] = {
168 0x42, 0x43, 0x4a, 0x4b, /* tda8290 */
169 0x60, 0x61, 0x62, 0x63, 0x64,
170 I2C_CLIENT_END
171 };
172
173 switch (type) {
174 case ADDRS_RADIO:
175 return radio_addrs;
176 case ADDRS_DEMOD:
177 return demod_addrs;
178 case ADDRS_TV:
179 return tv_addrs;
180 case ADDRS_TV_WITH_DEMOD:
181 return tv_addrs + 4;
182 }
183 return NULL;
184 }
185 EXPORT_SYMBOL_GPL(v4l2_i2c_tuner_addrs);
186