sh: pfc: Verify pin type encoding size at build time.

The encoding is tightly packed, and future changes (such as
pinconf-generic support) can easily lead to a situation where we violate
the encoding constraints and trample data bit/reg bits. This plugs in
some sanity checks by way of a BUILD_BUG_ON() to blow up if we fail to
fit.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/sh/pfc.c b/drivers/sh/pfc.c
index 8a9ae09603d6..ce4579ebd602 100644
--- a/drivers/sh/pfc.c
+++ b/drivers/sh/pfc.c
@@ -549,6 +549,11 @@ int register_sh_pfc(struct sh_pfc *pfc)
         int (*initroutine)(struct sh_pfc *) = NULL;
         int ret;
 
+        /*
+         * Ensure that the type encoding fits
+         */
+        BUILD_BUG_ON(PINMUX_FLAG_TYPE > ((1 << PINMUX_FLAG_DBIT_SHIFT) - 1));
+
         if (sh_pfc)
                 return -EBUSY;