[PATCH] spi: make spi_bus_type const

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

Now that the driver core can properly handle constant struct bus_type,
move the spi_bus_type variable to be a constant structure as well,
placing it into read-only memory which can not be modified at runtime.

Cc: Mark Brown <broonie@kernel.org>
Cc: linux-spi@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/spi/spi.c       | 2 +-
 include/linux/spi/spi.h | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 8ead7acb99f3..6e962befc450 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -459,7 +459,7 @@ static void spi_shutdown(struct device *dev)
 	}
 }
 
-struct bus_type spi_bus_type = {
+const struct bus_type spi_bus_type = {
 	.name		= "spi",
 	.dev_groups	= spi_dev_groups,
 	.match		= spi_match_device,
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index 255a0562aea5..f6c157dee55d 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -33,7 +33,7 @@ struct spi_message;
  * INTERFACES between SPI master-side drivers and SPI slave protocol handlers,
  * and SPI infrastructure.
  */
-extern struct bus_type spi_bus_type;
+extern const struct bus_type spi_bus_type;
 
 /**
  * struct spi_statistics - statistics for spi transfers
-- 
2.43.0