spi: sc18is602: Add OF device ID table

The driver doesn't have a struct of_device_id table but supported devices
are registered via Device Trees. This is working on the assumption that a
I2C device registered via OF will always match a legacy I2C device ID and
that the MODALIAS reported will always be of the form i2c:<device>.

But this could change in the future so the correct approach is to have an
OF device ID table if the devices are registered via OF.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-sc18is602.c

@@ -21,6 +21,7 @@
 #include <linux/i2c.h>
 #include <linux/delay.h>
 #include <linux/pm_runtime.h>
+#include <linux/of_device.h>
 #include <linux/of.h>
 #include <linux/platform_data/sc18is602.h>
 #include <linux/gpio/consumer.h>
@@ -271,7 +272,10 @@ static int sc18is602_probe(struct i2c_client *client,
 	hw->dev = dev;
 	hw->ctrl = 0xff;
 
-	hw->id = id->driver_data;
+	if (client->dev.of_node)
+		hw->id = (enum chips)of_device_get_match_data(&client->dev);
+	else
+		hw->id = id->driver_data;
 
 	switch (hw->id) {
 	case sc18is602:
@@ -323,9 +327,27 @@ static const struct i2c_device_id sc18is602_id[] = {
 };
 MODULE_DEVICE_TABLE(i2c, sc18is602_id);
 
+static const struct of_device_id sc18is602_of_match[] = {
+	{
+		.compatible = "nxp,sc18is602",
+		.data = (void *)sc18is602
+	},
+	{
+		.compatible = "nxp,sc18is602b",
+		.data = (void *)sc18is602b
+	},
+	{
+		.compatible = "nxp,sc18is603",
+		.data = (void *)sc18is603
+	},
+	{ },
+};
+MODULE_DEVICE_TABLE(of, sc18is602_of_match);
+
 static struct i2c_driver sc18is602_driver = {
 	.driver = {
 		.name = "sc18is602",
+		.of_match_table = of_match_ptr(sc18is602_of_match),
 	},
 	.probe = sc18is602_probe,
 	.id_table = sc18is602_id,