Commit 72fc2c7f authored Jul 24, 2012 by Laurent Pinchart Committed by Jean Delvare Jul 24, 2012

i2c: Fall back to emulated SMBus if the operation isn't supported natively



Adapter drivers might support only a subset of the SMBus operations
natively. Those drivers currently have to manually emulate unsupported
operations using I2C.

Make the i2c_smbus_xfer() function fall back to
i2c_smbus_xfer_emulated() when the adapter's .smbus_xfer() operation
returns -EOPNOTSUPP, like it already does when the .smbus_xfer()
operation isn't available at all.

[JD: Minor optimization.]

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

parent d47726c5

drivers/i2c/i2c-core.c

+10 −4

Original line number	Diff line number	Diff line
		@@ -2140,11 +2140,17 @@ s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags,
		break;
		}
		i2c_unlock_adapter(adapter);
		} else
		res = i2c_smbus_xfer_emulated(adapter, addr, flags, read_write,
		command, protocol, data);

		if (res != -EOPNOTSUPP \|\| !adapter->algo->master_xfer)
		return res;
		/*
		* Fall back to i2c_smbus_xfer_emulated if the adapter doesn't
		* implement native support for the SMBus operation.
		*/
		}

		return i2c_smbus_xfer_emulated(adapter, addr, flags, read_write,
		command, protocol, data);
		}
		EXPORT_SYMBOL(i2c_smbus_xfer);

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