On Wed, Jan 29, 2014 at 05:32:30PM -0500, Tom Rini wrote:
On Mon, Jan 27, 2014 at 10:53:26AM -0800, Darwin Rambo wrote:
Add bcm281xx architecture support code including a clock framework and chip reset. Define register block base addresses for the bcm281xx architecture and create an empty gpio header file required when CONFIG_CMD_GPIO is set.
[snip]
+/* Bitfield operations */
+/* Produces a mask of set bits covering a range of a 32-bit value */ +static inline u32 bitfield_mask(u32 shift, u32 width) +{
- return ((1 << width) - 1) << shift;
+}
+/* Extract the value of a bitfield found within a given register value */ +static inline u32 bitfield_extract(u32 reg_val, u32 shift, u32 width) +{
- return (reg_val & bitfield_mask(shift, width)) >> shift;
+}
+/* Replace the value of a bitfield found within a given register value */ +static inline u32 bitfield_replace(u32 reg_val, u32 shift, u32 width, u32 val) +{
- u32 mask = bitfield_mask(shift, width);
- return (reg_val & ~mask) | (val << shift);
+}
This all feels horribly generic, isn't there some linux header we've already got that I can't think off of the top of my head that gives us these kind of functions?
To add to what Darwin mentioned about bitops.h being insufficient...
The equivalent kernel implementations are wrapped up in the regmap/regmap-mmio helpers. That implementation is *very* heavyweight, and IMHO simply not appropriate for U-Boot (and often not useful in the kernel as well). A homegrown generic set of inline ops would seem to be ideal for U-Boot.
-Matt