release/src-rt-6.x/linux/linux-2.6/arch/sh/kernel/cpu/sh4a/clock-sh73180.c

   1 /*
   2  * arch/sh/kernel/cpu/sh4a/clock-sh73180.c
   3  *
   4  * SH73180 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  * SH73180 uses a common set of divisors, so this is quite simple..
  27  */
  28 static int divisors[] = { 1, 2, 3, 4, 6, 8, 12, 16 };
  29
  30 static void master_clk_init(struct clk *clk)
  31 {
  32         clk->rate *= divisors[ctrl_inl(FRQCR) & 0x0007];
  33 }
  34
  35 static struct clk_ops sh73180_master_clk_ops = {
  36         .init           = master_clk_init,
  37 };
  38
  39 static void module_clk_recalc(struct clk *clk)
  40 {
  41         int idx = (ctrl_inl(FRQCR) & 0x0007);
  42         clk->rate = clk->parent->rate / divisors[idx];
  43 }
  44
  45 static struct clk_ops sh73180_module_clk_ops = {
  46         .recalc         = module_clk_recalc,
  47 };
  48
  49 static void bus_clk_recalc(struct clk *clk)
  50 {
  51         int idx = (ctrl_inl(FRQCR) >> 12) & 0x0007;
  52         clk->rate = clk->parent->rate / divisors[idx];
  53 }
  54
  55 static struct clk_ops sh73180_bus_clk_ops = {
  56         .recalc         = bus_clk_recalc,
  57 };
  58
  59 static void cpu_clk_recalc(struct clk *clk)
  60 {
  61         int idx = (ctrl_inl(FRQCR) >> 20) & 0x0007;
  62         clk->rate = clk->parent->rate / divisors[idx];
  63 }
  64
  65 static struct clk_ops sh73180_cpu_clk_ops = {
  66         .recalc         = cpu_clk_recalc,
  67 };
  68
  69 static struct clk_ops *sh73180_clk_ops[] = {
  70         &sh73180_master_clk_ops,
  71         &sh73180_module_clk_ops,
  72         &sh73180_bus_clk_ops,
  73         &sh73180_cpu_clk_ops,
  74 };
  75
  76 void __init arch_init_clk_ops(struct clk_ops **ops, int idx)
  77 {
  78         if (idx < ARRAY_SIZE(sh73180_clk_ops))
  79                 *ops = sh73180_clk_ops[idx];
  80 }
  81