LXR linux/arch/sh/kernel/cpu/sh3/clock-sh7705.c

   1/*
   2 * arch/sh/kernel/cpu/sh3/clock-sh7705.c
   3 *
   4 * SH7705 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
  25/*
  26 * SH7705 uses the same divisors as the generic SH-3 case, it's just the
  27 * FRQCR layout that is a bit different..
  28 */
  29static int stc_multipliers[] = { 1, 2, 3, 4, 6, 1, 1, 1 };
  30static int ifc_divisors[]    = { 1, 2, 3, 4, 1, 1, 1, 1 };
  31static int pfc_divisors[]    = { 1, 2, 3, 4, 6, 1, 1, 1 };
  32
  33static void master_clk_init(struct clk *clk)
  34{
  35        clk->rate *= pfc_divisors[__raw_readw(FRQCR) & 0x0003];
  36}
  37
  38static struct sh_clk_ops sh7705_master_clk_ops = {
  39        .init           = master_clk_init,
  40};
  41
  42static unsigned long module_clk_recalc(struct clk *clk)
  43{
  44        int idx = __raw_readw(FRQCR) & 0x0003;
  45        return clk->parent->rate / pfc_divisors[idx];
  46}
  47
  48static struct sh_clk_ops sh7705_module_clk_ops = {
  49        .recalc         = module_clk_recalc,
  50};
  51
  52static unsigned long bus_clk_recalc(struct clk *clk)
  53{
  54        int idx = (__raw_readw(FRQCR) & 0x0300) >> 8;
  55        return clk->parent->rate / stc_multipliers[idx];
  56}
  57
  58static struct sh_clk_ops sh7705_bus_clk_ops = {
  59        .recalc         = bus_clk_recalc,
  60};
  61
  62static unsigned long cpu_clk_recalc(struct clk *clk)
  63{
  64        int idx = (__raw_readw(FRQCR) & 0x0030) >> 4;
  65        return clk->parent->rate / ifc_divisors[idx];
  66}
  67
  68static struct sh_clk_ops sh7705_cpu_clk_ops = {
  69        .recalc         = cpu_clk_recalc,
  70};
  71
  72static struct sh_clk_ops *sh7705_clk_ops[] = {
  73        &sh7705_master_clk_ops,
  74        &sh7705_module_clk_ops,
  75        &sh7705_bus_clk_ops,
  76        &sh7705_cpu_clk_ops,
  77};
  78
  79void __init arch_init_clk_ops(struct sh_clk_ops **ops, int idx)
  80{
  81        if (idx < ARRAY_SIZE(sh7705_clk_ops))
  82                *ops = sh7705_clk_ops[idx];
  83}
  84
  85