arch/sh/kernel/cpu/sh3/clock-sh7709.c

   1 /*
   2  * arch/sh/kernel/cpu/sh3/clock-sh7709.c
   3  *
   4  * SH7709 support for the clock framework
   5  *
   6  *  Copyright (C) 2005  Andriy Skulysh
   7  *
   8  * Based on arch/sh/kernel/cpu/sh3/clock-sh7705.c
   9  *  Copyright (C) 2005  Paul Mundt
  10  *
  11  * This file is subject to the terms and conditions of the GNU General Public
  12  * License.  See the file "COPYING" in the main directory of this archive
  13  * for more details.
  14  */
  15 #include <linux/init.h>
  16 #include <linux/kernel.h>
  17 #include <asm/clock.h>
  18 #include <asm/freq.h>
  19 #include <asm/io.h>
  20
  21 static int stc_multipliers[] = { 1, 2, 4, 8, 3, 6, 1, 1 };
  22 static int ifc_divisors[]    = { 1, 2, 4, 1, 3, 1, 1, 1 };
  23 static int pfc_divisors[]    = { 1, 2, 4, 1, 3, 6, 1, 1 };
  24
  25 static void set_bus_parent(struct clk *clk)
  26 {
  27         struct clk *bus_clk = clk_get(NULL, "bus_clk");
  28         clk->parent = bus_clk;
  29         clk_put(bus_clk);
  30 }
  31
  32 static void master_clk_init(struct clk *clk)
  33 {
  34         int frqcr = ctrl_inw(FRQCR);
  35         int idx = ((frqcr & 0x2000) >> 11) | (frqcr & 0x0003);
  36
  37         clk->rate *= pfc_divisors[idx];
  38 }
  39
  40 static struct clk_ops sh7709_master_clk_ops = {
  41         .init           = master_clk_init,
  42 };
  43
  44 static void module_clk_recalc(struct clk *clk)
  45 {
  46         int frqcr = ctrl_inw(FRQCR);
  47         int idx = ((frqcr & 0x2000) >> 11) | (frqcr & 0x0003);
  48
  49         clk->rate = clk->parent->rate / pfc_divisors[idx];
  50 }
  51
  52 static struct clk_ops sh7709_module_clk_ops = {
  53 #ifdef CLOCK_MODE_0_1_2_7
  54         .init           = set_bus_parent,
  55 #endif
  56         .recalc         = module_clk_recalc,
  57 };
  58
  59 static void bus_clk_recalc(struct clk *clk)
  60 {
  61         int frqcr = ctrl_inw(FRQCR);
  62         int idx = (frqcr & 0x0080) ?
  63                 ((frqcr & 0x8000) >> 13) | ((frqcr & 0x0030) >> 4) : 1;
  64
  65         clk->rate = clk->parent->rate * stc_multipliers[idx];
  66 }
  67
  68 static struct clk_ops sh7709_bus_clk_ops = {
  69         .recalc         = bus_clk_recalc,
  70 };
  71
  72 static void cpu_clk_recalc(struct clk *clk)
  73 {
  74         int frqcr = ctrl_inw(FRQCR);
  75         int idx = ((frqcr & 0x4000) >> 12) | ((frqcr & 0x000c) >> 2);
  76
  77         clk->rate = clk->parent->rate / ifc_divisors[idx];
  78 }
  79
  80 static struct clk_ops sh7709_cpu_clk_ops = {
  81         .init           = set_bus_parent,
  82         .recalc         = cpu_clk_recalc,
  83 };
  84
  85 static struct clk_ops *sh7709_clk_ops[] = {
  86         &sh7709_master_clk_ops,
  87         &sh7709_module_clk_ops,
  88         &sh7709_bus_clk_ops,
  89         &sh7709_cpu_clk_ops,
  90 };
  91
  92 void __init arch_init_clk_ops(struct clk_ops **ops, int idx)
  93 {
  94         if (idx < ARRAY_SIZE(sh7709_clk_ops))
  95                 *ops = sh7709_clk_ops[idx];
  96 }