spi: Initialize cs_gpio and cs_gpios with -ENOENT

The return value from of_get_named_gpio is -ENOENT when the given index
matches a hole in the "cs-gpios" property phandle list. However, the
default value of cs_gpio in struct spi_device and entries of cs_gpios in
struct spi_master is -EINVAL, which is documented to indicate that a
GPIO line should not be used for the given spi_device.

This sets the default value of cs_gpio in struct spi_device and entries
of cs_gpios in struct spi_master to -ENOENT. Thus, -ENOENT is the only
value used to indicate that no GPIO line should be used.

Signed-off-by: Andreas Larsson <andreas@gaisler.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 004b10f..bcca66c 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -334,7 +334,7 @@
 	spi->dev.parent = &master->dev;
 	spi->dev.bus = &spi_bus_type;
 	spi->dev.release = spidev_release;
-	spi->cs_gpio = -EINVAL;
+	spi->cs_gpio = -ENOENT;
 	device_initialize(&spi->dev);
 	return spi;
 }
@@ -1079,7 +1079,7 @@
 		return -ENOMEM;
 
 	for (i = 0; i < master->num_chipselect; i++)
-		cs[i] = -EINVAL;
+		cs[i] = -ENOENT;
 
 	for (i = 0; i < nb; i++)
 		cs[i] = of_get_named_gpio(np, "cs-gpios", i);