Linux Kernel  3.7.1
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clock-sh4.c
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1 /*
2  * arch/sh/kernel/cpu/sh4/clock-sh4.c
3  *
4  * Generic SH-4 support for the clock framework
5  *
6  * Copyright (C) 2005 Paul Mundt
7  *
8  * FRQCR parsing hacked out of arch/sh/kernel/time.c
9  *
10  * Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka
11  * Copyright (C) 2000 Philipp Rumpf <[email protected]>
12  * Copyright (C) 2002, 2003, 2004 Paul Mundt
13  * Copyright (C) 2002 M. R. Brown <[email protected]>
14  *
15  * This file is subject to the terms and conditions of the GNU General Public
16  * License. See the file "COPYING" in the main directory of this archive
17  * for more details.
18  */
19 #include <linux/init.h>
20 #include <linux/kernel.h>
21 #include <asm/clock.h>
22 #include <asm/freq.h>
23 #include <asm/io.h>
24 
25 static int ifc_divisors[] = { 1, 2, 3, 4, 6, 8, 1, 1 };
26 #define bfc_divisors ifc_divisors /* Same */
27 static int pfc_divisors[] = { 2, 3, 4, 6, 8, 2, 2, 2 };
28 
29 static void master_clk_init(struct clk *clk)
30 {
31  clk->rate *= pfc_divisors[__raw_readw(FRQCR) & 0x0007];
32 }
33 
34 static struct sh_clk_ops sh4_master_clk_ops = {
35  .init = master_clk_init,
36 };
37 
38 static unsigned long module_clk_recalc(struct clk *clk)
39 {
40  int idx = (__raw_readw(FRQCR) & 0x0007);
41  return clk->parent->rate / pfc_divisors[idx];
42 }
43 
44 static struct sh_clk_ops sh4_module_clk_ops = {
45  .recalc = module_clk_recalc,
46 };
47 
48 static unsigned long bus_clk_recalc(struct clk *clk)
49 {
50  int idx = (__raw_readw(FRQCR) >> 3) & 0x0007;
51  return clk->parent->rate / bfc_divisors[idx];
52 }
53 
54 static struct sh_clk_ops sh4_bus_clk_ops = {
55  .recalc = bus_clk_recalc,
56 };
57 
58 static unsigned long cpu_clk_recalc(struct clk *clk)
59 {
60  int idx = (__raw_readw(FRQCR) >> 6) & 0x0007;
61  return clk->parent->rate / ifc_divisors[idx];
62 }
63 
64 static struct sh_clk_ops sh4_cpu_clk_ops = {
65  .recalc = cpu_clk_recalc,
66 };
67 
68 static struct sh_clk_ops *sh4_clk_ops[] = {
69  &sh4_master_clk_ops,
70  &sh4_module_clk_ops,
71  &sh4_bus_clk_ops,
72  &sh4_cpu_clk_ops,
73 };
74 
75 void __init arch_init_clk_ops(struct sh_clk_ops **ops, int idx)
76 {
77  if (idx < ARRAY_SIZE(sh4_clk_ops))
78  *ops = sh4_clk_ops[idx];
79 }
80