release/src-rt-6.x.4708/linux/linux-2.6.36/arch/sh/kernel/cpu/sh3/clock-sh7709.c

   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 master_clk_init(struct clk *clk)
  26 {
  27         int frqcr = __raw_readw(FRQCR);
  28         int idx = ((frqcr & 0x2000) >> 11) | (frqcr & 0x0003);
  29
  30         clk->rate *= pfc_divisors[idx];
  31 }
  32
  33 static struct clk_ops sh7709_master_clk_ops = {
  34         .init           = master_clk_init,
  35 };
  36
  37 static unsigned long module_clk_recalc(struct clk *clk)
  38 {
  39         int frqcr = __raw_readw(FRQCR);
  40         int idx = ((frqcr & 0x2000) >> 11) | (frqcr & 0x0003);
  41
  42         return clk->parent->rate / pfc_divisors[idx];
  43 }
  44
  45 static struct clk_ops sh7709_module_clk_ops = {
  46         .recalc         = module_clk_recalc,
  47 };
  48
  49 static unsigned long bus_clk_recalc(struct clk *clk)
  50 {
  51         int frqcr = __raw_readw(FRQCR);
  52         int idx = (frqcr & 0x0080) ?
  53                 ((frqcr & 0x8000) >> 13) | ((frqcr & 0x0030) >> 4) : 1;
  54
  55         return clk->parent->rate * stc_multipliers[idx];
  56 }
  57
  58 static struct clk_ops sh7709_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 clk_ops sh7709_cpu_clk_ops = {
  71         .recalc         = cpu_clk_recalc,
  72 };
  73
  74 static struct clk_ops *sh7709_clk_ops[] = {
  75         &sh7709_master_clk_ops,
  76         &sh7709_module_clk_ops,
  77         &sh7709_bus_clk_ops,
  78         &sh7709_cpu_clk_ops,
  79 };
  80
  81 void __init arch_init_clk_ops(struct clk_ops **ops, int idx)
  82 {
  83         if (idx < ARRAY_SIZE(sh7709_clk_ops))
  84                 *ops = sh7709_clk_ops[idx];
  85 }