增加龙芯1c的硬件SPI相关接口

1 files changed, 43 insertions, 0 deletions

diff --git a/bsp/ls1cdev/libraries/ls1c_public.c b/bsp/ls1cdev/libraries/ls1c_public.c
index a04f68a877..3e57e9a50a 100644
--- a/bsp/ls1cdev/libraries/ls1c_public.c
+++ b/bsp/ls1cdev/libraries/ls1c_public.c
@@ -137,3 +137,46 @@ int ls1c_ffs(int x)
 }
 
 
+/*
+ * fls - find last (most-significant) bit set
+ * @x: the word to search
+ *
+ * This is defined the same way as ffs.
+ * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
+ */
+int ls1c_fls(int x)
+{
+    int r = 32;
+
+    if (!x)
+        return 0;
+    if (!(x & 0xffff0000u))
+    {
+        x <<= 16;
+        r -= 16;
+    }
+    if (!(x & 0xff000000u))
+    {
+        x <<= 8;
+        r -= 8;
+    }
+    if (!(x & 0xf0000000u))
+    {
+        x <<= 4;
+        r -= 4;
+    }
+    if (!(x & 0xc0000000u))
+    {
+        x <<= 2;
+        r -= 2;
+    }
+    if (!(x & 0x80000000u))
+    {
+        x <<= 1;
+        r -= 1;
+    }
+
+    return r;
+}
+
+