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 <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 /*
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
master_clk_init(struct clk * clk)33 static void master_clk_init(struct clk *clk)
34 {
35 clk->rate *= pfc_divisors[__raw_readw(FRQCR) & 0x0003];
36 }
37
38 static struct clk_ops sh7705_master_clk_ops = {
39 .init = master_clk_init,
40 };
41
module_clk_recalc(struct clk * clk)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 clk_ops sh7705_module_clk_ops = {
49 .recalc = module_clk_recalc,
50 };
51
bus_clk_recalc(struct clk * clk)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 clk_ops sh7705_bus_clk_ops = {
59 .recalc = bus_clk_recalc,
60 };
61
cpu_clk_recalc(struct clk * clk)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 clk_ops sh7705_cpu_clk_ops = {
69 .recalc = cpu_clk_recalc,
70 };
71
72 static struct 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
arch_init_clk_ops(struct clk_ops ** ops,int idx)79 void __init arch_init_clk_ops(struct clk_ops **ops, int idx)
80 {
81 if (idx < ARRAY_SIZE(sh7705_clk_ops))
82 *ops = sh7705_clk_ops[idx];
83 }
84
85