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clock-sh7705.c
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1 /*
2  * arch/sh/kernel/cpu/sh3/clock-sh7705.c
3  *
4  * SH7705 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 /*
26  * SH7705 uses the same divisors as the generic SH-3 case, it's just the
27  * FRQCR layout that is a bit different..
28  */
29 static int stc_multipliers[] = { 1, 2, 3, 4, 6, 1, 1, 1 };
30 static int ifc_divisors[] = { 1, 2, 3, 4, 1, 1, 1, 1 };
31 static int pfc_divisors[] = { 1, 2, 3, 4, 6, 1, 1, 1 };
32 
33 static void master_clk_init(struct clk *clk)
34 {
35  clk->rate *= pfc_divisors[__raw_readw(FRQCR) & 0x0003];
36 }
37 
38 static struct sh_clk_ops sh7705_master_clk_ops = {
39  .init = master_clk_init,
40 };
41 
42 static unsigned long module_clk_recalc(struct clk *clk)
43 {
44  int idx = __raw_readw(FRQCR) & 0x0003;
45  return clk->parent->rate / pfc_divisors[idx];
46 }
47 
48 static struct sh_clk_ops sh7705_module_clk_ops = {
49  .recalc = module_clk_recalc,
50 };
51 
52 static unsigned long bus_clk_recalc(struct clk *clk)
53 {
54  int idx = (__raw_readw(FRQCR) & 0x0300) >> 8;
55  return clk->parent->rate / stc_multipliers[idx];
56 }
57 
58 static struct sh_clk_ops sh7705_bus_clk_ops = {
59  .recalc = bus_clk_recalc,
60 };
61 
62 static unsigned long cpu_clk_recalc(struct clk *clk)
63 {
64  int idx = (__raw_readw(FRQCR) & 0x0030) >> 4;
65  return clk->parent->rate / ifc_divisors[idx];
66 }
67 
68 static struct sh_clk_ops sh7705_cpu_clk_ops = {
69  .recalc = cpu_clk_recalc,
70 };
71 
72 static struct sh_clk_ops *sh7705_clk_ops[] = {
73  &sh7705_master_clk_ops,
74  &sh7705_module_clk_ops,
75  &sh7705_bus_clk_ops,
76  &sh7705_cpu_clk_ops,
77 };
78 
79 void __init arch_init_clk_ops(struct sh_clk_ops **ops, int idx)
80 {
81  if (idx < ARRAY_SIZE(sh7705_clk_ops))
82  *ops = sh7705_clk_ops[idx];
83 }
84