xref: /openbmc/linux/arch/sh/kernel/cpu/sh3/clock-sh3.c (revision c4f7ac64)
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 
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 
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 
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 
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 
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