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authorCodrin Ciubotariu <codrin.ciubotariu@freescale.com>2015-07-24 16:55:25 +0300
committerYork Sun <yorksun@freescale.com>2015-09-21 08:29:46 -0700
commit8756de2824e7c282afca59db3706aa5d473a7067 (patch)
tree391c5f2d2a91fe2a65c6558ef36934846e16271d /include
parent440873dfc44eec4f92c482068c8be4c9f900032f (diff)
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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>
Diffstat (limited to 'include')
-rw-r--r--include/bitfield.h32
1 files changed, 32 insertions, 0 deletions
diff --git a/include/bitfield.h b/include/bitfield.h
index b884c74..a59f3c2 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);
+}