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>

1 files changed, 32 insertions, 0 deletions

diff --git a/Documentation/sh/clk.txt b/Documentation/sh/clk.txt
new file mode 100644
index 000000000000..9aef710e9a4b
--- /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