release/src-rt-6.x.4708/linux/linux-2.6.36/arch/sh/kernel/cpu/sh5/clock-sh5.c

   1 /*
   2  * arch/sh/kernel/cpu/sh5/clock-sh5.c
   3  *
   4  * SH-5 support for the clock framework
   5  *
   6  *  Copyright (C) 2008  Paul Mundt
   7  *
   8  * This file is subject to the terms and conditions of the GNU General Public
   9  * License.  See the file "COPYING" in the main directory of this archive
  10  * for more details.
  11  */
  12 #include <linux/init.h>
  13 #include <linux/kernel.h>
  14 #include <asm/clock.h>
  15 #include <asm/io.h>
  16
  17 static int ifc_table[] = { 2, 4, 6, 8, 10, 12, 16, 24 };
  18
  19 /* Clock, Power and Reset Controller */
  20 #define CPRC_BLOCK_OFF  0x01010000
  21 #define CPRC_BASE       (PHYS_PERIPHERAL_BLOCK + CPRC_BLOCK_OFF)
  22
  23 static unsigned long cprc_base;
  24
  25 static void master_clk_init(struct clk *clk)
  26 {
  27         int idx = (__raw_readl(cprc_base + 0x00) >> 6) & 0x0007;
  28         clk->rate *= ifc_table[idx];
  29 }
  30
  31 static struct clk_ops sh5_master_clk_ops = {
  32         .init           = master_clk_init,
  33 };
  34
  35 static unsigned long module_clk_recalc(struct clk *clk)
  36 {
  37         int idx = (__raw_readw(cprc_base) >> 12) & 0x0007;
  38         return clk->parent->rate / ifc_table[idx];
  39 }
  40
  41 static struct clk_ops sh5_module_clk_ops = {
  42         .recalc         = module_clk_recalc,
  43 };
  44
  45 static unsigned long bus_clk_recalc(struct clk *clk)
  46 {
  47         int idx = (__raw_readw(cprc_base) >> 3) & 0x0007;
  48         return clk->parent->rate / ifc_table[idx];
  49 }
  50
  51 static struct clk_ops sh5_bus_clk_ops = {
  52         .recalc         = bus_clk_recalc,
  53 };
  54
  55 static unsigned long cpu_clk_recalc(struct clk *clk)
  56 {
  57         int idx = (__raw_readw(cprc_base) & 0x0007);
  58         return clk->parent->rate / ifc_table[idx];
  59 }
  60
  61 static struct clk_ops sh5_cpu_clk_ops = {
  62         .recalc         = cpu_clk_recalc,
  63 };
  64
  65 static struct clk_ops *sh5_clk_ops[] = {
  66         &sh5_master_clk_ops,
  67         &sh5_module_clk_ops,
  68         &sh5_bus_clk_ops,
  69         &sh5_cpu_clk_ops,
  70 };
  71
  72 void __init arch_init_clk_ops(struct clk_ops **ops, int idx)
  73 {
  74         cprc_base = (unsigned long)ioremap_nocache(CPRC_BASE, 1024);
  75         BUG_ON(!cprc_base);
  76
  77         if (idx < ARRAY_SIZE(sh5_clk_ops))
  78                 *ops = sh5_clk_ops[idx];
  79 }