diff options
| author | Luca Ceresoli <luca@lucaceresoli.net> | 2022-04-13 00:59:20 +0530 |
|---|---|---|
| committer | Vignesh Raghavendra <vigneshr@ti.com> | 2022-05-31 13:57:33 +0530 |
| commit | c0310e2d8c4fd7df44bc194a295314dd104df623 (patch) | |
| tree | d3a672a00cd0d9f5b9bcd30d5c5d9af4f74609ae | |
| parent | 7d6c29ee9f2ff21927e430ffbe937ab96f5ed8e5 (diff) | |
i2c: core: let adapters be notified of client attach/detach
An adapter might need to know when a new device is about to be
added. This will soon bee needed to implement an "I2C address
translator" (ATR for short), a device that propagates I2C transactions
with a different slave address (an "alias" address). An ATR driver
needs to know when a slave is being added to find a suitable alias and
program the device translation map.
Add an attach/detach callback pair to allow adapter drivers to be
notified of clients being added and removed.
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
| -rw-r--r-- | drivers/i2c/i2c-core-base.c | 18 | ||||
| -rw-r--r-- | include/linux/i2c.h | 16 |
2 files changed, 33 insertions, 1 deletions
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c index bdce6d3e5327..7fab4214dc93 100644 --- a/drivers/i2c/i2c-core-base.c +++ b/drivers/i2c/i2c-core-base.c @@ -921,15 +921,23 @@ i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *inf } } + if (adap->attach_ops && + adap->attach_ops->attach_client && + adap->attach_ops->attach_client(adap, info, client) != 0) + goto out_free_props; + status = device_register(&client->dev); if (status) - goto out_free_props; + goto out_detach_client; dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n", client->name, dev_name(&client->dev)); return client; +out_detach_client: + if (adap->attach_ops && adap->attach_ops->detach_client) + adap->attach_ops->detach_client(adap, client); out_free_props: if (info->properties) device_remove_properties(&client->dev); @@ -952,9 +960,17 @@ EXPORT_SYMBOL_GPL(i2c_new_client_device); */ void i2c_unregister_device(struct i2c_client *client) { + struct i2c_adapter *adap; + if (IS_ERR_OR_NULL(client)) return; + adap = client->adapter; + + if (adap->attach_ops && + adap->attach_ops->detach_client) + adap->attach_ops->detach_client(adap, client); + if (client->dev.of_node) { of_node_clear_flag(client->dev.of_node, OF_POPULATED); of_node_put(client->dev.of_node); diff --git a/include/linux/i2c.h b/include/linux/i2c.h index a670ae129f4b..752f049faae9 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -561,6 +561,21 @@ struct i2c_lock_operations { }; /** + * struct i2c_attach_operations - callbacks to notify client attach/detach + * @attach_client: Notify of new client being attached + * @detach_client: Notify of new client being detached + * + * Both ops are optional. + */ +struct i2c_attach_operations { + int (*attach_client)(struct i2c_adapter *adapter, + const struct i2c_board_info *info, + const struct i2c_client *client); + void (*detach_client)(struct i2c_adapter *adapter, + const struct i2c_client *client); +}; + +/** * struct i2c_timings - I2C timing information * @bus_freq_hz: the bus frequency in Hz * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification @@ -702,6 +717,7 @@ struct i2c_adapter { /* data fields that are valid for all devices */ const struct i2c_lock_operations *lock_ops; + const struct i2c_attach_operations *attach_ops; struct rt_mutex bus_lock; struct rt_mutex mux_lock; |