xref: /openbmc/linux/arch/sh/kernel/cpu/sh3/clock-sh7709.c (revision 643d1f7f)
1 /*
2  * arch/sh/kernel/cpu/sh3/clock-sh7709.c
3  *
4  * SH7709 support for the clock framework
5  *
6  *  Copyright (C) 2005  Andriy Skulysh
7  *
8  * Based on arch/sh/kernel/cpu/sh3/clock-sh7705.c
9  *  Copyright (C) 2005  Paul Mundt
10  *
11  * This file is subject to the terms and conditions of the GNU General Public
12  * License.  See the file "COPYING" in the main directory of this archive
13  * for more details.
14  */
15 #include <linux/init.h>
16 #include <linux/kernel.h>
17 #include <asm/clock.h>
18 #include <asm/freq.h>
19 #include <asm/io.h>
20 
21 static int stc_multipliers[] = { 1, 2, 4, 8, 3, 6, 1, 1 };
22 static int ifc_divisors[]    = { 1, 2, 4, 1, 3, 1, 1, 1 };
23 static int pfc_divisors[]    = { 1, 2, 4, 1, 3, 6, 1, 1 };
24 
25 static void set_bus_parent(struct clk *clk)
26 {
27 	struct clk *bus_clk = clk_get(NULL, "bus_clk");
28 	clk->parent = bus_clk;
29 	clk_put(bus_clk);
30 }
31 
32 static void master_clk_init(struct clk *clk)
33 {
34 	int frqcr = ctrl_inw(FRQCR);
35 	int idx = ((frqcr & 0x2000) >> 11) | (frqcr & 0x0003);
36 
37 	clk->rate *= pfc_divisors[idx];
38 }
39 
40 static struct clk_ops sh7709_master_clk_ops = {
41 	.init		= master_clk_init,
42 };
43 
44 static void module_clk_recalc(struct clk *clk)
45 {
46 	int frqcr = ctrl_inw(FRQCR);
47 	int idx = ((frqcr & 0x2000) >> 11) | (frqcr & 0x0003);
48 
49 	clk->rate = clk->parent->rate / pfc_divisors[idx];
50 }
51 
52 static struct clk_ops sh7709_module_clk_ops = {
53 #ifdef CLOCK_MODE_0_1_2_7
54 	.init		= set_bus_parent,
55 #endif
56 	.recalc		= module_clk_recalc,
57 };
58 
59 static void bus_clk_recalc(struct clk *clk)
60 {
61 	int frqcr = ctrl_inw(FRQCR);
62 	int idx = (frqcr & 0x0080) ?
63 		((frqcr & 0x8000) >> 13) | ((frqcr & 0x0030) >> 4) : 1;
64 
65 	clk->rate = clk->parent->rate * stc_multipliers[idx];
66 }
67 
68 static struct clk_ops sh7709_bus_clk_ops = {
69 	.recalc		= bus_clk_recalc,
70 };
71 
72 static void cpu_clk_recalc(struct clk *clk)
73 {
74 	int frqcr = ctrl_inw(FRQCR);
75 	int idx = ((frqcr & 0x4000) >> 12) | ((frqcr & 0x000c) >> 2);
76 
77 	clk->rate = clk->parent->rate / ifc_divisors[idx];
78 }
79 
80 static struct clk_ops sh7709_cpu_clk_ops = {
81 	.init		= set_bus_parent,
82 	.recalc		= cpu_clk_recalc,
83 };
84 
85 static struct clk_ops *sh7709_clk_ops[] = {
86 	&sh7709_master_clk_ops,
87 	&sh7709_module_clk_ops,
88 	&sh7709_bus_clk_ops,
89 	&sh7709_cpu_clk_ops,
90 };
91 
92 void __init arch_init_clk_ops(struct clk_ops **ops, int idx)
93 {
94 	if (idx < ARRAY_SIZE(sh7709_clk_ops))
95 		*ops = sh7709_clk_ops[idx];
96 }
97