From 8756de2824e7c282afca59db3706aa5d473a7067 Mon Sep 17 00:00:00 2001
From: Codrin Ciubotariu <codrin.ciubotariu@freescale.com>
Date: Fri, 24 Jul 2015 16:55:25 +0300
Subject: [PATCH] include/bitfield: Add new bitfield operations
These new operations allow manipulation of bitfields
within a word by using a mask instead of width and
shift values to extract/replace the bitfields.
Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@freescale.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
Reviewed-by: York Sun <yorksun@freescale.com>
---
include/bitfield.h | 32 ++++++++++++++++++++++++++++++++
1 file changed, 32 insertions(+)
diff --git a/include/bitfield.h b/include/bitfield.h
index b884c74600..a59f3c279a 100644
--- a/include/bitfield.h
+++ b/include/bitfield.h
@@ -27,6 +27,12 @@
* 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.
*/
@@ -56,3 +62,29 @@ static inline uint bitfield_replace(uint reg_val, uint shift, uint width,
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);
+}
--
2.39.5