arch/sh/kernel/cpu/sh3/clock-sh7705.c

   1 /*
   2  * arch/sh/kernel/cpu/sh3/clock-sh7705.c
   3  *
   4  * SH7705 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  * SH7705 uses the same divisors as the generic SH-3 case, it's just the
  27  * FRQCR layout that is a bit different..
  28  */
  29 static int stc_multipliers[] = { 1, 2, 3, 4, 6, 1, 1, 1 };
  30 static int ifc_divisors[]    = { 1, 2, 3, 4, 1, 1, 1, 1 };
  31 static int pfc_divisors[]    = { 1, 2, 3, 4, 6, 1, 1, 1 };
  32
  33 static void master_clk_init(struct clk *clk)
  34 {
  35         clk->rate *= pfc_divisors[__raw_readw(FRQCR) & 0x0003];
  36 }
  37
  38 static struct clk_ops sh7705_master_clk_ops = {
  39         .init           = master_clk_init,
  40 };
  41
  42 static unsigned long module_clk_recalc(struct clk *clk)
  43 {
  44         int idx = __raw_readw(FRQCR) & 0x0003;
  45         return clk->parent->rate / pfc_divisors[idx];
  46 }
  47
  48 static struct clk_ops sh7705_module_clk_ops = {
  49         .recalc         = module_clk_recalc,
  50 };
  51
  52 static unsigned long bus_clk_recalc(struct clk *clk)
  53 {
  54         int idx = (__raw_readw(FRQCR) & 0x0300) >> 8;
  55         return clk->parent->rate / stc_multipliers[idx];
  56 }
  57
  58 static struct clk_ops sh7705_bus_clk_ops = {
  59         .recalc         = bus_clk_recalc,
  60 };
  61
  62 static unsigned long cpu_clk_recalc(struct clk *clk)
  63 {
  64         int idx = (__raw_readw(FRQCR) & 0x0030) >> 4;
  65         return clk->parent->rate / ifc_divisors[idx];
  66 }
  67
  68 static struct clk_ops sh7705_cpu_clk_ops = {
  69         .recalc         = cpu_clk_recalc,
  70 };
  71
  72 static struct clk_ops *sh7705_clk_ops[] = {
  73         &sh7705_master_clk_ops,
  74         &sh7705_module_clk_ops,
  75         &sh7705_bus_clk_ops,
  76         &sh7705_cpu_clk_ops,
  77 };
  78
  79 void __init arch_init_clk_ops(struct clk_ops **ops, int idx)
  80 {
  81         if (idx < ARRAY_SIZE(sh7705_clk_ops))
  82                 *ops = sh7705_clk_ops[idx];
  83 }
  84