tile-srom: allow the driver to be built as a module

The code was already configured that way, but the Kconfig
file didn't support requesting it.

A buglet caused a null pointer deref when unloading the
module, but this commit also corrects that issue.

Signed-off-by: Chris Metcalf <cmetcalf@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 3 insertions, 2 deletions

diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index dc4f35ad19d0..c17604f8c7c1 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -577,7 +577,7 @@ config DEVPORT
 source "drivers/s390/char/Kconfig"
 
 config TILE_SROM
-        bool "Character-device access via hypervisor to the Tilera SPI ROM"
+        tristate "Character-device access via hypervisor to the Tilera SPI ROM"
         depends on TILE
         default y
         ---help---
diff --git a/drivers/char/tile-srom.c b/drivers/char/tile-srom.c
index 398800edb2cc..3d4cca64b2d4 100644
--- a/drivers/char/tile-srom.c
+++ b/drivers/char/tile-srom.c
@@ -312,7 +312,8 @@ ATTRIBUTE_GROUPS(srom_dev);
 
 static char *srom_devnode(struct device *dev, umode_t *mode)
 {
-        *mode = S_IRUGO | S_IWUSR;
+        if (mode)
+                *mode = 0644;
         return kasprintf(GFP_KERNEL, "srom/%s", dev_name(dev));
 }