Linux Kernel  3.7.1
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
clock-sh3.c
Go to the documentation of this file.
1 /*
2  * arch/sh/kernel/cpu/sh3/clock-sh3.c
3  *
4  * Generic SH-3 support for the clock framework
5  *
6  * Copyright (C) 2005 Paul Mundt
7  *
8  * FRQCR parsing hacked out of arch/sh/kernel/time.c
9  *
10  * Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka
11  * Copyright (C) 2000 Philipp Rumpf <[email protected]>
12  * Copyright (C) 2002, 2003, 2004 Paul Mundt
13  * Copyright (C) 2002 M. R. Brown <[email protected]>
14  *
15  * This file is subject to the terms and conditions of the GNU General Public
16  * License. See the file "COPYING" in the main directory of this archive
17  * for more details.
18  */
19 #include <linux/init.h>
20 #include <linux/kernel.h>
21 #include <asm/clock.h>
22 #include <asm/freq.h>
23 #include <asm/io.h>
24 
25 static int stc_multipliers[] = { 1, 2, 3, 4, 6, 1, 1, 1 };
26 static int ifc_divisors[] = { 1, 2, 3, 4, 1, 1, 1, 1 };
27 static int pfc_divisors[] = { 1, 2, 3, 4, 6, 1, 1, 1 };
28 
29 static void master_clk_init(struct clk *clk)
30 {
31  int frqcr = __raw_readw(FRQCR);
32  int idx = ((frqcr & 0x2000) >> 11) | (frqcr & 0x0003);
33 
34  clk->rate *= pfc_divisors[idx];
35 }
36 
37 static struct sh_clk_ops sh3_master_clk_ops = {
38  .init = master_clk_init,
39 };
40 
41 static unsigned long module_clk_recalc(struct clk *clk)
42 {
43  int frqcr = __raw_readw(FRQCR);
44  int idx = ((frqcr & 0x2000) >> 11) | (frqcr & 0x0003);
45 
46  return clk->parent->rate / pfc_divisors[idx];
47 }
48 
49 static struct sh_clk_ops sh3_module_clk_ops = {
50  .recalc = module_clk_recalc,
51 };
52 
53 static unsigned long bus_clk_recalc(struct clk *clk)
54 {
55  int frqcr = __raw_readw(FRQCR);
56  int idx = ((frqcr & 0x8000) >> 13) | ((frqcr & 0x0030) >> 4);
57 
58  return clk->parent->rate / stc_multipliers[idx];
59 }
60 
61 static struct sh_clk_ops sh3_bus_clk_ops = {
62  .recalc = bus_clk_recalc,
63 };
64 
65 static unsigned long cpu_clk_recalc(struct clk *clk)
66 {
67  int frqcr = __raw_readw(FRQCR);
68  int idx = ((frqcr & 0x4000) >> 12) | ((frqcr & 0x000c) >> 2);
69 
70  return clk->parent->rate / ifc_divisors[idx];
71 }
72 
73 static struct sh_clk_ops sh3_cpu_clk_ops = {
74  .recalc = cpu_clk_recalc,
75 };
76 
77 static struct sh_clk_ops *sh3_clk_ops[] = {
78  &sh3_master_clk_ops,
79  &sh3_module_clk_ops,
80  &sh3_bus_clk_ops,
81  &sh3_cpu_clk_ops,
82 };
83 
84 void __init arch_init_clk_ops(struct sh_clk_ops **ops, int idx)
85 {
86  if (idx < ARRAY_SIZE(sh3_clk_ops))
87  *ops = sh3_clk_ops[idx];
88 }
89