colibri_imx6: fix video stdout in default environment

[oweals/u-boot.git] / include / bitfield.h

diff --git a/include/bitfield.h b/include/bitfield.h
index ec4815c8e05179508c00cce24655acd7382ba62e..d3ceeedccda681b884f63422d0a49dc4804562c0 100644 (file)
--- a/include/bitfield.h
+++ b/include/bitfield.h
@@ -1,7 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * Copyright 2013 Broadcom Corporation.
- *
- * SPDX-License-Identifier:      GPL-2.0+
  */
 
 /*
@@ -27,10 +26,17 @@
  * old = bitfield_extract(old_reg_val, 10, 5);
  * new_reg_val = bitfield_replace(old_reg_val, 10, 5, new);
  *
+ * or
+ *
+ * mask = bitfield_mask(10, 5);
+ * old = bitfield_extract_by_mask(old_reg_val, mask);
+ * new_reg_val = bitfield_replace_by_mask(old_reg_val, mask, new);
+ *
  * The numbers 10 and 5 could for example come from data
  * tables which describe all bitfields in all registers.
  */
 
+#include <linux/bitops.h>
 #include <linux/types.h>
 
 /* Produces a mask of set bits covering a range of a uint value */
@@ -54,5 +60,31 @@ static inline uint bitfield_replace(uint reg_val, uint shift, uint width,
 {
        uint mask = bitfield_mask(shift, width);
 
-       return (reg_val & ~mask) | (bitfield_val << shift);
+       return (reg_val & ~mask) | ((bitfield_val << shift) & mask);
+}
+
+/* Produces a shift of the bitfield given a mask */
+static inline uint bitfield_shift(uint mask)
+{
+       return mask ? ffs(mask) - 1 : 0;
+}
+
+/* Extract the value of a bitfield found within a given register value */
+static inline uint bitfield_extract_by_mask(uint reg_val, uint mask)
+{
+       uint shift = bitfield_shift(mask);
+
+       return (reg_val & mask) >> shift;
+}
+
+/*
+ * Replace the value of a bitfield found within a given register value
+ * Returns the newly modified uint value with the replaced field.
+ */
+static inline uint bitfield_replace_by_mask(uint reg_val, uint mask,
+                                           uint bitfield_val)
+{
+       uint shift = bitfield_shift(mask);
+
+       return (reg_val & ~mask) | ((bitfield_val << shift) & mask);
 }