release/src-rt-6.x.4708/linux/linux-2.6.36/arch/sh/kernel/cpu/sh4a/clock-sh7763.c

   1 /*
   2  * arch/sh/kernel/cpu/sh4a/clock-sh7763.c
   3  *
   4  * SH7763 support for the clock framework
   5  *
   6  *  Copyright (C) 2005  Paul Mundt
   7  *  Copyright (C) 2007  Yoshihiro Shimoda
   8  *
   9  * This file is subject to the terms and conditions of the GNU General Public
  10  * License.  See the file "COPYING" in the main directory of this archive
  11  * for more details.
  12  */
  13 #include <linux/init.h>
  14 #include <linux/kernel.h>
  15 #include <linux/io.h>
  16 #include <asm/clkdev.h>
  17 #include <asm/clock.h>
  18 #include <asm/freq.h>
  19 #include <asm/io.h>
  20
  21 static int bfc_divisors[] = { 1, 1, 1, 8, 1, 1, 1, 1 };
  22 static int p0fc_divisors[] = { 1, 1, 1, 8, 1, 1, 1, 1 };
  23 static int cfc_divisors[] = { 1, 1, 4, 1, 1, 1, 1, 1 };
  24
  25 static void master_clk_init(struct clk *clk)
  26 {
  27         clk->rate *= p0fc_divisors[(__raw_readl(FRQCR) >> 4) & 0x07];
  28 }
  29
  30 static struct clk_ops sh7763_master_clk_ops = {
  31         .init           = master_clk_init,
  32 };
  33
  34 static unsigned long module_clk_recalc(struct clk *clk)
  35 {
  36         int idx = ((__raw_readl(FRQCR) >> 4) & 0x07);
  37         return clk->parent->rate / p0fc_divisors[idx];
  38 }
  39
  40 static struct clk_ops sh7763_module_clk_ops = {
  41         .recalc         = module_clk_recalc,
  42 };
  43
  44 static unsigned long bus_clk_recalc(struct clk *clk)
  45 {
  46         int idx = ((__raw_readl(FRQCR) >> 16) & 0x07);
  47         return clk->parent->rate / bfc_divisors[idx];
  48 }
  49
  50 static struct clk_ops sh7763_bus_clk_ops = {
  51         .recalc         = bus_clk_recalc,
  52 };
  53
  54 static struct clk_ops sh7763_cpu_clk_ops = {
  55         .recalc         = followparent_recalc,
  56 };
  57
  58 static struct clk_ops *sh7763_clk_ops[] = {
  59         &sh7763_master_clk_ops,
  60         &sh7763_module_clk_ops,
  61         &sh7763_bus_clk_ops,
  62         &sh7763_cpu_clk_ops,
  63 };
  64
  65 void __init arch_init_clk_ops(struct clk_ops **ops, int idx)
  66 {
  67         if (idx < ARRAY_SIZE(sh7763_clk_ops))
  68                 *ops = sh7763_clk_ops[idx];
  69 }
  70
  71 static unsigned long shyway_clk_recalc(struct clk *clk)
  72 {
  73         int idx = ((__raw_readl(FRQCR) >> 20) & 0x07);
  74         return clk->parent->rate / cfc_divisors[idx];
  75 }
  76
  77 static struct clk_ops sh7763_shyway_clk_ops = {
  78         .recalc         = shyway_clk_recalc,
  79 };
  80
  81 static struct clk sh7763_shyway_clk = {
  82         .flags          = CLK_ENABLE_ON_INIT,
  83         .ops            = &sh7763_shyway_clk_ops,
  84 };
  85
  86 /*
  87  * Additional SH7763-specific on-chip clocks that aren't already part of the
  88  * clock framework
  89  */
  90 static struct clk *sh7763_onchip_clocks[] = {
  91         &sh7763_shyway_clk,
  92 };
  93
  94 #define CLKDEV_CON_ID(_id, _clk) { .con_id = _id, .clk = _clk }
  95
  96 static struct clk_lookup lookups[] = {
  97         /* main clocks */
  98         CLKDEV_CON_ID("shyway_clk", &sh7763_shyway_clk),
  99 };
 100
 101 int __init arch_clk_init(void)
 102 {
 103         struct clk *clk;
 104         int i, ret = 0;
 105
 106         cpg_clk_init();
 107
 108         clk = clk_get(NULL, "master_clk");
 109         for (i = 0; i < ARRAY_SIZE(sh7763_onchip_clocks); i++) {
 110                 struct clk *clkp = sh7763_onchip_clocks[i];
 111
 112                 clkp->parent = clk;
 113                 ret |= clk_register(clkp);
 114         }
 115
 116         clk_put(clk);
 117
 118         clkdev_add_table(lookups, ARRAY_SIZE(lookups));
 119
 120         return ret;
 121 }