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| author | dmitry pervushin <dimka@nomadgs.com> | 2007-04-24 06:39:09 +0200 |
|---|---|---|
| committer | Paul Mundt <lethal@hera.kernel.org> | 2007-05-07 04:11:56 +0200 |
| commit | 1929cb340b74904c130fdf3de3fe5bbedb68a5aa (patch) | |
| tree | 2675de406fca78e6bfd5b29535bbb220a167bc2e /Documentation/sh/clk.txt | |
| parent | sh: hp6xx pata_platform support. (diff) | |
| download | linux-1929cb340b74904c130fdf3de3fe5bbedb68a5aa.tar.xz linux-1929cb340b74904c130fdf3de3fe5bbedb68a5aa.zip | |
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>
Diffstat (limited to 'Documentation/sh/clk.txt')
| -rw-r--r-- | Documentation/sh/clk.txt | 32 |
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 |