i2c: zx2967: use core to detect 'no zero length' quirk

And don't reimplement in the driver.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

drivers/i2c/busses/i2c-zx2967.c

@@ -281,9 +281,6 @@ static int zx2967_i2c_xfer_msg(struct zx2967_i2c *i2c,
 	int ret;
 	int i;
 
-	if (msg->len == 0)
-		return -EINVAL;
-
 	zx2967_i2c_flush_fifos(i2c);
 
 	i2c->cur_trans = msg->buf;
@@ -498,6 +495,10 @@ static const struct i2c_algorithm zx2967_i2c_algo = {
 	.functionality = zx2967_i2c_func,
 };
 
+static const struct i2c_adapter_quirks zx2967_i2c_quirks = {
+	.flags = I2C_AQ_NO_ZERO_LEN,
+};
+
 static const struct of_device_id zx2967_i2c_of_match[] = {
 	{ .compatible = "zte,zx296718-i2c", },
 	{ },
@@ -568,6 +569,7 @@ static int zx2967_i2c_probe(struct platform_device *pdev)
 	strlcpy(i2c->adap.name, "zx2967 i2c adapter",
 		sizeof(i2c->adap.name));
 	i2c->adap.algo = &zx2967_i2c_algo;
+	i2c->adap.quirks = &zx2967_i2c_quirks;
 	i2c->adap.nr = pdev->id;
 	i2c->adap.dev.parent = &pdev->dev;
 	i2c->adap.dev.of_node = pdev->dev.of_node;