i2c: core: add managed function for adding i2c adapters

mainline inclusion
from mainline-v5.12-rc7
07740c92
category: feature
bugzilla: 175140
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=07740c92ae57ca21204f1e0c6f59272cdf3190cc

---------------------------

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: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: NDmitry Osipenko <digetx@gmail.com>
Signed-off-by: NYicong Yang <yangyicong@hisilicon.com>
Signed-off-by: NWolfram Sang <wsa@kernel.org>
Reviewed-by: NJay Fang <f.fangjian@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/i2c/i2c-core-base.c

@@ -1702,6 +1702,32 @@ 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)
 {

include/linux/i2c.h

@@ -846,6 +846,8 @@ static inline void i2c_mark_adapter_resumed(struct i2c_adapter *adap)
  */
 #if IS_ENABLED(CONFIG_I2C)
 int i2c_add_adapter(struct i2c_adapter *adap);
+extern 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);