sh: SH7722 clock framework support.
This adds support for the SH7722 (MobileR) to the clock framework.
Signed-off-by: dmitry pervushin <dimka@nomadgs.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/Documentation/sh/clk.txt b/Documentation/sh/clk.txt
new file mode 100644
index 0000000..9aef710
--- /dev/null
+++ b/Documentation/sh/clk.txt
@@ -0,0 +1,32 @@
+Clock framework on SuperH architecture
+
+The framework on SH extends existing API by the function clk_set_rate_ex,
+which prototype is as follows:
+
+ clk_set_rate_ex (struct clk *clk, unsigned long rate, int algo_id)
+
+The algo_id parameter is used to specify algorithm used to recalculate clocks,
+adjanced to clock, specified as first argument. It is assumed that algo_id==0
+means no changes to adjanced clock
+
+Internally, the clk_set_rate_ex forwards request to clk->ops->set_rate method,
+if it is present in ops structure. The method should set the clock rate and adjust
+all needed clocks according to the passed algo_id.
+Exact values for algo_id are machine-dependend. For the sh7722, the following
+values are defined:
+
+ NO_CHANGE = 0,
+ IUS_N1_N1, /* I:U = N:1, U:Sh = N:1 */
+ IUS_322, /* I:U:Sh = 3:2:2 */
+ IUS_522, /* I:U:Sh = 5:2:2 */
+ IUS_N11, /* I:U:Sh = N:1:1 */
+ SB_N1, /* Sh:B = N:1 */
+ SB3_N1, /* Sh:B3 = N:1 */
+ SB3_32, /* Sh:B3 = 3:2 */
+ SB3_43, /* Sh:B3 = 4:3 */
+ SB3_54, /* Sh:B3 = 5:4 */
+ BP_N1, /* B:P = N:1 */
+ IP_N1 /* I:P = N:1 */
+
+Each of these constants means relation between clocks that can be set via the FRQCR
+register