LXR linux/arch/sh/kernel/cpu/sh4/clock-sh4.c

   1/*
   2 * arch/sh/kernel/cpu/sh4/clock-sh4.c
   3 *
   4 * Generic SH-4 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 <prumpf@tux.org>
  12 *  Copyright (C) 2002, 2003, 2004  Paul Mundt
  13 *  Copyright (C) 2002  M. R. Brown  <mrbrown@linux-sh.org>
  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
  25static int ifc_divisors[] = { 1, 2, 3, 4, 6, 8, 1, 1 };
  26#define bfc_divisors ifc_divisors       /* Same */
  27static int pfc_divisors[] = { 2, 3, 4, 6, 8, 2, 2, 2 };
  28
  29static void master_clk_init(struct clk *clk)
  30{
  31        clk->rate *= pfc_divisors[ctrl_inw(FRQCR) & 0x0007];
  32}
  33
  34static struct clk_ops sh4_master_clk_ops = {
  35        .init           = master_clk_init,
  36};
  37
  38static unsigned long module_clk_recalc(struct clk *clk)
  39{
  40        int idx = (ctrl_inw(FRQCR) & 0x0007);
  41        return clk->parent->rate / pfc_divisors[idx];
  42}
  43
  44static struct clk_ops sh4_module_clk_ops = {
  45        .recalc         = module_clk_recalc,
  46};
  47
  48static unsigned long bus_clk_recalc(struct clk *clk)
  49{
  50        int idx = (ctrl_inw(FRQCR) >> 3) & 0x0007;
  51        return clk->parent->rate / bfc_divisors[idx];
  52}
  53
  54static struct clk_ops sh4_bus_clk_ops = {
  55        .recalc         = bus_clk_recalc,
  56};
  57
  58static unsigned long cpu_clk_recalc(struct clk *clk)
  59{
  60        int idx = (ctrl_inw(FRQCR) >> 6) & 0x0007;
  61        return clk->parent->rate / ifc_divisors[idx];
  62}
  63
  64static struct clk_ops sh4_cpu_clk_ops = {
  65        .recalc         = cpu_clk_recalc,
  66};
  67
  68static struct clk_ops *sh4_clk_ops[] = {
  69        &sh4_master_clk_ops,
  70        &sh4_module_clk_ops,
  71        &sh4_bus_clk_ops,
  72        &sh4_cpu_clk_ops,
  73};
  74
  75void __init arch_init_clk_ops(struct clk_ops **ops, int idx)
  76{
  77        if (idx < ARRAY_SIZE(sh4_clk_ops))
  78                *ops = sh4_clk_ops[idx];
  79}
  80
  81