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

   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 <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 stc_multipliers[] = { 1, 2, 3, 4, 6, 1, 1, 1 };
  26static int ifc_divisors[]    = { 1, 2, 3, 4, 1, 1, 1, 1 };
  27static int pfc_divisors[]    = { 1, 2, 3, 4, 6, 1, 1, 1 };
  28
  29static void master_clk_init(struct clk *clk)
  30{
  31        int frqcr = ctrl_inw(FRQCR);
  32        int idx = ((frqcr & 0x2000) >> 11) | (frqcr & 0x0003);
  33
  34        clk->rate *= pfc_divisors[idx];
  35}
  36
  37static struct clk_ops sh3_master_clk_ops = {
  38        .init           = master_clk_init,
  39};
  40
  41static unsigned long module_clk_recalc(struct clk *clk)
  42{
  43        int frqcr = ctrl_inw(FRQCR);
  44        int idx = ((frqcr & 0x2000) >> 11) | (frqcr & 0x0003);
  45
  46        return clk->parent->rate / pfc_divisors[idx];
  47}
  48
  49static struct clk_ops sh3_module_clk_ops = {
  50        .recalc         = module_clk_recalc,
  51};
  52
  53static unsigned long bus_clk_recalc(struct clk *clk)
  54{
  55        int frqcr = ctrl_inw(FRQCR);
  56        int idx = ((frqcr & 0x8000) >> 13) | ((frqcr & 0x0030) >> 4);
  57
  58        return clk->parent->rate / stc_multipliers[idx];
  59}
  60
  61static struct clk_ops sh3_bus_clk_ops = {
  62        .recalc         = bus_clk_recalc,
  63};
  64
  65static unsigned long cpu_clk_recalc(struct clk *clk)
  66{
  67        int frqcr = ctrl_inw(FRQCR);
  68        int idx = ((frqcr & 0x4000) >> 12) | ((frqcr & 0x000c) >> 2);
  69
  70        return clk->parent->rate / ifc_divisors[idx];
  71}
  72
  73static struct clk_ops sh3_cpu_clk_ops = {
  74        .recalc         = cpu_clk_recalc,
  75};
  76
  77static struct 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
  84void __init arch_init_clk_ops(struct clk_ops **ops, int idx)
  85{
  86        if (idx < ARRAY_SIZE(sh3_clk_ops))
  87                *ops = sh3_clk_ops[idx];
  88}
  89
  90