xref: /openbmc/linux/arch/sh/kernel/cpu/sh4/clock-sh4.c (revision da1d9caf)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * arch/sh/kernel/cpu/sh4/clock-sh4.c
4  *
5  * Generic SH-4 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 ifc_divisors[] = { 1, 2, 3, 4, 6, 8, 1, 1 };
23 #define bfc_divisors ifc_divisors	/* Same */
24 static int pfc_divisors[] = { 2, 3, 4, 6, 8, 2, 2, 2 };
25 
26 static void master_clk_init(struct clk *clk)
27 {
28 	clk->rate *= pfc_divisors[__raw_readw(FRQCR) & 0x0007];
29 }
30 
31 static struct sh_clk_ops sh4_master_clk_ops = {
32 	.init		= master_clk_init,
33 };
34 
35 static unsigned long module_clk_recalc(struct clk *clk)
36 {
37 	int idx = (__raw_readw(FRQCR) & 0x0007);
38 	return clk->parent->rate / pfc_divisors[idx];
39 }
40 
41 static struct sh_clk_ops sh4_module_clk_ops = {
42 	.recalc		= module_clk_recalc,
43 };
44 
45 static unsigned long bus_clk_recalc(struct clk *clk)
46 {
47 	int idx = (__raw_readw(FRQCR) >> 3) & 0x0007;
48 	return clk->parent->rate / bfc_divisors[idx];
49 }
50 
51 static struct sh_clk_ops sh4_bus_clk_ops = {
52 	.recalc		= bus_clk_recalc,
53 };
54 
55 static unsigned long cpu_clk_recalc(struct clk *clk)
56 {
57 	int idx = (__raw_readw(FRQCR) >> 6) & 0x0007;
58 	return clk->parent->rate / ifc_divisors[idx];
59 }
60 
61 static struct sh_clk_ops sh4_cpu_clk_ops = {
62 	.recalc		= cpu_clk_recalc,
63 };
64 
65 static struct sh_clk_ops *sh4_clk_ops[] = {
66 	&sh4_master_clk_ops,
67 	&sh4_module_clk_ops,
68 	&sh4_bus_clk_ops,
69 	&sh4_cpu_clk_ops,
70 };
71 
72 void __init arch_init_clk_ops(struct sh_clk_ops **ops, int idx)
73 {
74 	if (idx < ARRAY_SIZE(sh4_clk_ops))
75 		*ops = sh4_clk_ops[idx];
76 }
77 
78