1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * arch/sh/kernel/cpu/sh3/clock-sh3.c
4 *
5 * Generic SH-3 support for the clock framework
6 *
7 * Copyright (C) 2005 Paul Mundt
8 *
9 * FRQCR parsing hacked out of arch/sh/kernel/time.c
10 *
11 * Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka
12 * Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>
13 * Copyright (C) 2002, 2003, 2004 Paul Mundt
14 * Copyright (C) 2002 M. R. Brown <mrbrown@linux-sh.org>
15 */
16 #include <linux/init.h>
17 #include <linux/kernel.h>
18 #include <asm/clock.h>
19 #include <asm/freq.h>
20 #include <asm/io.h>
21
22 static int stc_multipliers[] = { 1, 2, 3, 4, 6, 1, 1, 1 };
23 static int ifc_divisors[] = { 1, 2, 3, 4, 1, 1, 1, 1 };
24 static int pfc_divisors[] = { 1, 2, 3, 4, 6, 1, 1, 1 };
25
master_clk_init(struct clk * clk)26 static void master_clk_init(struct clk *clk)
27 {
28 int frqcr = __raw_readw(FRQCR);
29 int idx = ((frqcr & 0x2000) >> 11) | (frqcr & 0x0003);
30
31 clk->rate *= pfc_divisors[idx];
32 }
33
34 static struct sh_clk_ops sh3_master_clk_ops = {
35 .init = master_clk_init,
36 };
37
module_clk_recalc(struct clk * clk)38 static unsigned long module_clk_recalc(struct clk *clk)
39 {
40 int frqcr = __raw_readw(FRQCR);
41 int idx = ((frqcr & 0x2000) >> 11) | (frqcr & 0x0003);
42
43 return clk->parent->rate / pfc_divisors[idx];
44 }
45
46 static struct sh_clk_ops sh3_module_clk_ops = {
47 .recalc = module_clk_recalc,
48 };
49
bus_clk_recalc(struct clk * clk)50 static unsigned long bus_clk_recalc(struct clk *clk)
51 {
52 int frqcr = __raw_readw(FRQCR);
53 int idx = ((frqcr & 0x8000) >> 13) | ((frqcr & 0x0030) >> 4);
54
55 return clk->parent->rate / stc_multipliers[idx];
56 }
57
58 static struct sh_clk_ops sh3_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 frqcr = __raw_readw(FRQCR);
65 int idx = ((frqcr & 0x4000) >> 12) | ((frqcr & 0x000c) >> 2);
66
67 return clk->parent->rate / ifc_divisors[idx];
68 }
69
70 static struct sh_clk_ops sh3_cpu_clk_ops = {
71 .recalc = cpu_clk_recalc,
72 };
73
74 static struct sh_clk_ops *sh3_clk_ops[] = {
75 &sh3_master_clk_ops,
76 &sh3_module_clk_ops,
77 &sh3_bus_clk_ops,
78 &sh3_cpu_clk_ops,
79 };
80
arch_init_clk_ops(struct sh_clk_ops ** ops,int idx)81 void __init arch_init_clk_ops(struct sh_clk_ops **ops, int idx)
82 {
83 if (idx < ARRAY_SIZE(sh3_clk_ops))
84 *ops = sh3_clk_ops[idx];
85 }
86
87