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
  25 static int ifc_divisors[] = { 1, 2, 3, 4, 6, 8, 1, 1 };
  26 #define bfc_divisors ifc_divisors       /* Same */
  27 static int pfc_divisors[] = { 2, 3, 4, 6, 8, 2, 2, 2 };
  28
  29 static void master_clk_init(struct clk *clk)
  30 {
  31         clk->rate *= pfc_divisors[__raw_readw(FRQCR) & 0x0007];
  32 }
  33
  34 static struct clk_ops sh4_master_clk_ops = {
  35         .init           = master_clk_init,
  36 };
  37
  38 static unsigned long module_clk_recalc(struct clk *clk)
  39 {
  40         int idx = (__raw_readw(FRQCR) & 0x0007);
  41         return clk->parent->rate / pfc_divisors[idx];
  42 }
  43
  44 static struct clk_ops sh4_module_clk_ops = {
  45         .recalc         = module_clk_recalc,
  46 };
  47
  48 static unsigned long bus_clk_recalc(struct clk *clk)
  49 {
  50         int idx = (__raw_readw(FRQCR) >> 3) & 0x0007;
  51         return clk->parent->rate / bfc_divisors[idx];
  52 }
  53
  54 static struct clk_ops sh4_bus_clk_ops = {
  55         .recalc         = bus_clk_recalc,
  56 };
  57
  58 static unsigned long cpu_clk_recalc(struct clk *clk)
  59 {
  60         int idx = (__raw_readw(FRQCR) >> 6) & 0x0007;
  61         return clk->parent->rate / ifc_divisors[idx];
  62 }
  63
  64 static struct clk_ops sh4_cpu_clk_ops = {
  65         .recalc         = cpu_clk_recalc,
  66 };
  67
  68 static 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
  75 void __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