spi: sh-msiof: ignore driver probing if it was MSIOF Sound

Renesas MSIOF (Clock-Synchronized Serial Interface with FIFO) can work as
both SPI and I2S. MSIOF-I2S will use Audio Graph Card/Card2 driver which
Of-Graph in DT.

MSIOF-SPI/I2S are using same DT compatible properties.
MSIOF-I2S         uses Of-Graph for Audio-Graph-Card/Card2,
MSIOF-SPI doesn't use  Of-Graph.

Check "port" node when driver probing

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/87wmbi2x0g.wl-kuninori.morimoto.gx@renesas.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: morimoto

drivers/spi/spi-sh-msiof.c

@@ -20,6 +20,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/of_graph.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/sh_dma.h>
@@ -1281,6 +1282,11 @@ static int sh_msiof_spi_probe(struct platform_device *pdev)
 	int i;
 	int ret;
 
+	/* Check whether MSIOF is used as I2S mode or SPI mode by checking "port" node */
+	struct device_node *port __free(device_node) = of_graph_get_next_port(dev->of_node, NULL);
+	if (port) /* It was MSIOF-I2S */
+		return -ENODEV;
+
 	chipdata = of_device_get_match_data(dev);
 	if (chipdata) {
 		info = sh_msiof_spi_parse_dt(dev);