xref: /openbmc/linux/arch/sh/kernel/cpu/sh3/clock-sh7705.c (revision 7f877908)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * arch/sh/kernel/cpu/sh3/clock-sh7705.c
4  *
5  * SH7705 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 /*
23  * SH7705 uses the same divisors as the generic SH-3 case, it's just the
24  * FRQCR layout that is a bit different..
25  */
26 static int stc_multipliers[] = { 1, 2, 3, 4, 6, 1, 1, 1 };
27 static int ifc_divisors[]    = { 1, 2, 3, 4, 1, 1, 1, 1 };
28 static int pfc_divisors[]    = { 1, 2, 3, 4, 6, 1, 1, 1 };
29 
30 static void master_clk_init(struct clk *clk)
31 {
32 	clk->rate *= pfc_divisors[__raw_readw(FRQCR) & 0x0003];
33 }
34 
35 static struct sh_clk_ops sh7705_master_clk_ops = {
36 	.init		= master_clk_init,
37 };
38 
39 static unsigned long module_clk_recalc(struct clk *clk)
40 {
41 	int idx = __raw_readw(FRQCR) & 0x0003;
42 	return clk->parent->rate / pfc_divisors[idx];
43 }
44 
45 static struct sh_clk_ops sh7705_module_clk_ops = {
46 	.recalc		= module_clk_recalc,
47 };
48 
49 static unsigned long bus_clk_recalc(struct clk *clk)
50 {
51 	int idx = (__raw_readw(FRQCR) & 0x0300) >> 8;
52 	return clk->parent->rate / stc_multipliers[idx];
53 }
54 
55 static struct sh_clk_ops sh7705_bus_clk_ops = {
56 	.recalc		= bus_clk_recalc,
57 };
58 
59 static unsigned long cpu_clk_recalc(struct clk *clk)
60 {
61 	int idx = (__raw_readw(FRQCR) & 0x0030) >> 4;
62 	return clk->parent->rate / ifc_divisors[idx];
63 }
64 
65 static struct sh_clk_ops sh7705_cpu_clk_ops = {
66 	.recalc		= cpu_clk_recalc,
67 };
68 
69 static struct sh_clk_ops *sh7705_clk_ops[] = {
70 	&sh7705_master_clk_ops,
71 	&sh7705_module_clk_ops,
72 	&sh7705_bus_clk_ops,
73 	&sh7705_cpu_clk_ops,
74 };
75 
76 void __init arch_init_clk_ops(struct sh_clk_ops **ops, int idx)
77 {
78 	if (idx < ARRAY_SIZE(sh7705_clk_ops))
79 		*ops = sh7705_clk_ops[idx];
80 }
81 
82