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linux-next/Documentation/sh/clk.txt
Matt LaPlante d91958815d Documentation cleanup: trivial misspelling, punctuation, and grammar corrections.
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 12:00:06 -07:00

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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-dependent. 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