[PATCH v6 1/5] i2c: core: add managed function for adding i2c adapters

From: Yicong Yang
Date: Wed Mar 31 2021 - 09:39:58 EST


Some I2C controller drivers will only unregister the I2C
adapter in their .remove() callback, which can be done
by simply using a managed variant to add the I2C adapter.

So add the managed functions for adding the I2C adapter.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Reviewed-by: Dmitry Osipenko <digetx@xxxxxxxxx>
Signed-off-by: Yicong Yang <yangyicong@xxxxxxxxxxxxx>
---
drivers/i2c/i2c-core-base.c | 26 ++++++++++++++++++++++++++
include/linux/i2c.h | 1 +
2 files changed, 27 insertions(+)

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 63ebf72..de9402c 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -1703,6 +1703,32 @@ void i2c_del_adapter(struct i2c_adapter *adap)
}
EXPORT_SYMBOL(i2c_del_adapter);

+static void devm_i2c_del_adapter(void *adapter)
+{
+ i2c_del_adapter(adapter);
+}
+
+/**
+ * devm_i2c_add_adapter - device-managed variant of i2c_add_adapter()
+ * @dev: managing device for adding this I2C adapter
+ * @adapter: the adapter to add
+ * Context: can sleep
+ *
+ * Add adapter with dynamic bus number, same with i2c_add_adapter()
+ * but the adapter will be auto deleted on driver detach.
+ */
+int devm_i2c_add_adapter(struct device *dev, struct i2c_adapter *adapter)
+{
+ int ret;
+
+ ret = i2c_add_adapter(adapter);
+ if (ret)
+ return ret;
+
+ return devm_add_action_or_reset(dev, devm_i2c_del_adapter, adapter);
+}
+EXPORT_SYMBOL_GPL(devm_i2c_add_adapter);
+
static void i2c_parse_timing(struct device *dev, char *prop_name, u32 *cur_val_p,
u32 def_val, bool use_def)
{
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 5662265..10bd0b0 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -844,6 +844,7 @@ static inline void i2c_mark_adapter_resumed(struct i2c_adapter *adap)
*/
#if IS_ENABLED(CONFIG_I2C)
int i2c_add_adapter(struct i2c_adapter *adap);
+int devm_i2c_add_adapter(struct device *dev, struct i2c_adapter *adapter);
void i2c_del_adapter(struct i2c_adapter *adap);
int i2c_add_numbered_adapter(struct i2c_adapter *adap);

--
2.8.1