[PATCH 2/4] i2c: addition of client reg/unreg callbacks

Alain Volmat
2020-05-05T05:52:44Z

Addition of two callbacks reg_client and unreg_client that can be
implemented by adapter drivers in order to take action whenever a
client is being registered to it.

Signed-off-by: Alain Volmat <alain.volmat@st.com>
---
drivers/i2c/i2c-core-base.c | 11 +++++++++++
include/linux/i2c.h | 6 ++++++
2 files changed, 17 insertions(+)

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 2e4560671183..4c84c6264314 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -319,6 +319,12 @@ static int i2c_device_probe(struct device *dev)
if (!client)
return 0;

+ if (client->adapter->algo->reg_client) {
+ status = client->adapter->algo->reg_client(client);
+ if (status)
+ return status;
+ }
+
driver = to_i2c_driver(dev->driver);

client->irq = client->init_irq;
@@ -417,6 +423,8 @@ static int i2c_device_probe(struct device *dev)
put_sync_adapter:
if (client->flags & I2C_CLIENT_HOST_NOTIFY)
pm_runtime_put_sync(&client->adapter->dev);
+ if (client->adapter->algo->reg_client)
+ client->adapter->algo->unreg_client(client);

return status;
}
@@ -445,6 +453,9 @@ static int i2c_device_remove(struct device *dev)
if (client->flags & I2C_CLIENT_HOST_NOTIFY)
pm_runtime_put(&client->adapter->dev);

+ if (client->adapter->algo->unreg_client)
+ client->adapter->algo->unreg_client(client);
+
return status;
}

diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 45d36ba4826b..61b838caf454 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -509,6 +509,8 @@ i2c_register_board_info(int busnum, struct i2c_board_info const *info,
* so e.g. PMICs can be accessed very late before shutdown. Optional.
* @functionality: Return the flags that this algorithm/adapter pair supports
* from the ``I2C_FUNC_*`` flags.
+ * @reg_client: Callback informing that a new client is being registered
+ * @unreg_client: Callback informing that a client is being removed
* @reg_slave: Register given client to I2C slave mode of this adapter
* @unreg_slave: Unregister given client from I2C slave mode of this adapter
*
@@ -545,6 +547,10 @@ struct i2c_algorithm {
/* To determine what the adapter supports */
u32 (*functionality)(struct i2c_adapter *adap);

+ /* To inform the adapter of the probe/remove of a client */
+ int (*reg_client)(struct i2c_client *client);
+ void (*unreg_client)(struct i2c_client *client);
+
#if IS_ENABLED(CONFIG_I2C_SLAVE)
int (*reg_slave)(struct i2c_client *client);
int (*unreg_slave)(struct i2c_client *client);
--
2.17.1