185 lines · c
1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * v4l2-i2c - I2C helpers for Video4Linux24 */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 client17 * explicitly. We cannot rely on18 * i2c_del_adapter to always unregister19 * clients for us, since if the i2c bus is a20 * platform bus, then it is never deleted.21 *22 * Device tree or ACPI based devices must not23 * be unregistered as they have not been24 * registered by us, and would not be25 * 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(sd->name, sizeof(sd->name), "%s%s %d-%04x", devname, postfix,41 i2c_adapter_id(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, client);55 i2c_set_clientdata(client, 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_subdev62*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(adapter, info, probe_addrs,78 NULL);79 else80 client = i2c_new_client_device(adapter, info);81 82 /*83 * Note: by loading the module first we are certain that c->driver84 * will be set if the driver was found. If the module was not loaded85 * 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 finally87 * loaded. This delay-load mechanism doesn't work if other drivers88 * want to use the i2c device, so explicitly loading the module89 * 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(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's101 * use count as well.102 */103 if (__v4l2_device_register_subdev(v4l2_dev, sd, sd->owner))104 sd = NULL;105 /* Decrease the module use count to match the first try_module_get. */106 module_put(client->dev.driver->owner);107 108error:109 /*110 * If we have a client but no subdev, then something went wrong and111 * we must unregister the client.112 */113 if (!IS_ERR(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 and129 * 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 tuner151 * 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#endif159 0x60,160 I2C_CLIENT_END161 };162 static const unsigned short demod_addrs[] = {163 0x42, 0x43, 0x4a, 0x4b,164 I2C_CLIENT_END165 };166 static const unsigned short tv_addrs[] = {167 0x42, 0x43, 0x4a, 0x4b, /* tda8290 */168 0x60, 0x61, 0x62, 0x63, 0x64,169 I2C_CLIENT_END170 };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