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 11 void 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 31 void 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(sd->name, sizeof(sd->name), "%s%s %d-%04x", devname, postfix, 41 i2c_adapter_id(client->adapter), client->addr); 42 } 43 EXPORT_SYMBOL_GPL(v4l2_i2c_subdev_set_name); 44 45 void 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, client); 55 i2c_set_clientdata(client, sd); 56 v4l2_i2c_subdev_set_name(sd, client, NULL, NULL); 57 } 58 EXPORT_SYMBOL_GPL(v4l2_i2c_subdev_init); 59 60 /* Load an i2c sub-device. */ 61 struct 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_probed_device(adapter, info, probe_addrs, 78 NULL); 79 else 80 client = i2c_new_device(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 (!client || !client->dev.driver) 92 goto error; 93 94 /* Lock the module so we can safely get the v4l2_subdev pointer */ 95 if (!try_module_get(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(client->dev.driver->owner); 107 108 error: 109 /* 110 * If we have a client but no subdev, then something went wrong and 111 * we must unregister the client. 112 */ 113 if (client && !sd) 114 i2c_unregister_device(client); 115 return sd; 116 } 117 EXPORT_SYMBOL_GPL(v4l2_i2c_new_subdev_board); 118 119 struct 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 } 138 EXPORT_SYMBOL_GPL(v4l2_i2c_new_subdev); 139 140 /* Return i2c client address of v4l2_subdev. */ 141 unsigned 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 } 147 EXPORT_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 */ 153 const 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 } 184 EXPORT_SYMBOL_GPL(v4l2_i2c_tuner_addrs); 185