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Documentation / sh / clk.txt

Based on kernel version 2.6.26. Page generated on 2008-07-16 21:13 EST.

1	Clock framework on SuperH architecture
2	
3	The framework on SH extends existing API by the function clk_set_rate_ex,
4	which prototype is as follows:
5	
6	    clk_set_rate_ex (struct clk *clk, unsigned long rate, int algo_id)
7	
8	The algo_id parameter is used to specify algorithm used to recalculate clocks,
9	adjanced to clock, specified as first argument. It is assumed that algo_id==0
10	means no changes to adjanced clock
11	
12	Internally, the clk_set_rate_ex forwards request to clk->ops->set_rate method,
13	if it is present in ops structure. The method should set the clock rate and adjust
14	all needed clocks according to the passed algo_id.
15	Exact values for algo_id are machine-dependend. For the sh7722, the following
16	values are defined:
17	
18		NO_CHANGE	= 0,
19		IUS_N1_N1,	/* I:U = N:1, U:Sh = N:1 */
20		IUS_322,	/* I:U:Sh = 3:2:2	 */
21		IUS_522,	/* I:U:Sh = 5:2:2 	 */
22		IUS_N11,	/* I:U:Sh = N:1:1	 */
23		SB_N1,		/* Sh:B = N:1		 */
24		SB3_N1,		/* Sh:B3 = N:1		 */
25		SB3_32,		/* Sh:B3 = 3:2		 */
26		SB3_43,		/* Sh:B3 = 4:3		 */
27		SB3_54,		/* Sh:B3 = 5:4		 */
28		BP_N1,		/* B:P	 = N:1		 */
29		IP_N1		/* I:P	 = N:1		 */
30	
31	Each of these constants means relation between clocks that can be set via the FRQCR
32	register
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