1 /*
2 * arch/sh/kernel/cpu/sh3/clock-sh3.c
3 *
4 * Generic SH-3 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 <prumpf@tux.org>
12 * Copyright (C) 2002, 2003, 2004 Paul Mundt
13 * Copyright (C) 2002 M. R. Brown <mrbrown@linux-sh.org>
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 stc_multipliers[] = { 1, 2, 3, 4, 6, 1, 1, 1 };
26 static int ifc_divisors[] = { 1, 2, 3, 4, 1, 1, 1, 1 };
27 static int pfc_divisors[] = { 1, 2, 3, 4, 6, 1, 1, 1 };
28
master_clk_init(struct clk * clk)29 static void master_clk_init(struct clk *clk)
30 {
31 int frqcr = __raw_readw(FRQCR);
32 int idx = ((frqcr & 0x2000) >> 11) | (frqcr & 0x0003);
33
34 clk->rate *= pfc_divisors[idx];
35 }
36
37 static struct sh_clk_ops sh3_master_clk_ops = {
38 .init = master_clk_init,
39 };
40
module_clk_recalc(struct clk * clk)41 static unsigned long module_clk_recalc(struct clk *clk)
42 {
43 int frqcr = __raw_readw(FRQCR);
44 int idx = ((frqcr & 0x2000) >> 11) | (frqcr & 0x0003);
45
46 return clk->parent->rate / pfc_divisors[idx];
47 }
48
49 static struct sh_clk_ops sh3_module_clk_ops = {
50 .recalc = module_clk_recalc,
51 };
52
bus_clk_recalc(struct clk * clk)53 static unsigned long bus_clk_recalc(struct clk *clk)
54 {
55 int frqcr = __raw_readw(FRQCR);
56 int idx = ((frqcr & 0x8000) >> 13) | ((frqcr & 0x0030) >> 4);
57
58 return clk->parent->rate / stc_multipliers[idx];
59 }
60
61 static struct sh_clk_ops sh3_bus_clk_ops = {
62 .recalc = bus_clk_recalc,
63 };
64
cpu_clk_recalc(struct clk * clk)65 static unsigned long cpu_clk_recalc(struct clk *clk)
66 {
67 int frqcr = __raw_readw(FRQCR);
68 int idx = ((frqcr & 0x4000) >> 12) | ((frqcr & 0x000c) >> 2);
69
70 return clk->parent->rate / ifc_divisors[idx];
71 }
72
73 static struct sh_clk_ops sh3_cpu_clk_ops = {
74 .recalc = cpu_clk_recalc,
75 };
76
77 static struct sh_clk_ops *sh3_clk_ops[] = {
78 &sh3_master_clk_ops,
79 &sh3_module_clk_ops,
80 &sh3_bus_clk_ops,
81 &sh3_cpu_clk_ops,
82 };
83
arch_init_clk_ops(struct sh_clk_ops ** ops,int idx)84 void __init arch_init_clk_ops(struct sh_clk_ops **ops, int idx)
85 {
86 if (idx < ARRAY_SIZE(sh3_clk_ops))
87 *ops = sh3_clk_ops[idx];
88 }
89
90