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authordmitry pervushin <dimka@nomadgs.com>2007-04-24 00:39:09 -0400
committerPaul Mundt <lethal@hera.kernel.org>2007-05-06 22:11:56 -0400
commit1929cb340b74904c130fdf3de3fe5bbedb68a5aa (patch)
tree2675de406fca78e6bfd5b29535bbb220a167bc2e /Documentation/sh
parent34a780a0afeb8f99c9ca9934f4cc0822541769c6 (diff)
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>
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1Clock framework on SuperH architecture
2
3The framework on SH extends existing API by the function clk_set_rate_ex,
4which prototype is as follows:
5
6 clk_set_rate_ex (struct clk *clk, unsigned long rate, int algo_id)
7
8The algo_id parameter is used to specify algorithm used to recalculate clocks,
9adjanced to clock, specified as first argument. It is assumed that algo_id==0
10means no changes to adjanced clock
11
12Internally, the clk_set_rate_ex forwards request to clk->ops->set_rate method,
13if it is present in ops structure. The method should set the clock rate and adjust
14all needed clocks according to the passed algo_id.
15Exact values for algo_id are machine-dependend. For the sh7722, the following
16values 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
31Each of these constants means relation between clocks that can be set via the FRQCR
32register