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

   1 /*
   2  * arch/sh/kernel/cpu/sh3/clock-sh3.c
   3  *
   4  * Generic SH-3 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 stc_multipliers[] = { 1, 2, 3, 4, 6, 1, 1, 1 };
  26 static int ifc_divisors[]    = { 1, 2, 3, 4, 1, 1, 1, 1 };
  27 static int pfc_divisors[]    = { 1, 2, 3, 4, 6, 1, 1, 1 };
  28
  29 static void master_clk_init(struct clk *clk)
  30 {
  31         int frqcr = __raw_readw(FRQCR);
  32         int idx = ((frqcr & 0x2000) >> 11) | (frqcr & 0x0003);
  33
  34         clk->rate *= pfc_divisors[idx];
  35 }
  36
  37 static struct clk_ops sh3_master_clk_ops = {
  38         .init           = master_clk_init,
  39 };
  40
  41 static unsigned long module_clk_recalc(struct clk *clk)
  42 {
  43         int frqcr = __raw_readw(FRQCR);
  44         int idx = ((frqcr & 0x2000) >> 11) | (frqcr & 0x0003);
  45
  46         return clk->parent->rate / pfc_divisors[idx];
  47 }
  48
  49 static struct clk_ops sh3_module_clk_ops = {
  50         .recalc         = module_clk_recalc,
  51 };
  52
  53 static unsigned long bus_clk_recalc(struct clk *clk)
  54 {
  55         int frqcr = __raw_readw(FRQCR);
  56         int idx = ((frqcr & 0x8000) >> 13) | ((frqcr & 0x0030) >> 4);
  57
  58         return clk->parent->rate / stc_multipliers[idx];
  59 }
  60
  61 static struct clk_ops sh3_bus_clk_ops = {
  62         .recalc         = bus_clk_recalc,
  63 };
  64
  65 static unsigned long cpu_clk_recalc(struct clk *clk)
  66 {
  67         int frqcr = __raw_readw(FRQCR);
  68         int idx = ((frqcr & 0x4000) >> 12) | ((frqcr & 0x000c) >> 2);
  69
  70         return clk->parent->rate / ifc_divisors[idx];
  71 }
  72
  73 static struct clk_ops sh3_cpu_clk_ops = {
  74         .recalc         = cpu_clk_recalc,
  75 };
  76
  77 static struct clk_ops *sh3_clk_ops[] = {
  78         &sh3_master_clk_ops,
  79         &sh3_module_clk_ops,
  80         &sh3_bus_clk_ops,
  81         &sh3_cpu_clk_ops,
  82 };
  83
  84 void __init arch_init_clk_ops(struct clk_ops **ops, int idx)
  85 {
  86         if (idx < ARRAY_SIZE(sh3_clk_ops))
  87                 *ops = sh3_clk_ops[idx];
  88 }
  89