+/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Copyright 2013 Broadcom Corporation.
- *
- * SPDX-License-Identifier: GPL-2.0+
*/
/*
* 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 */
{
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);
}