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

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * arch/sh/kernel/cpu/sh3/clock-sh3.c
   4  *
   5  * Generic SH-3 support for the clock framework
   6  *
   7  *  Copyright (C) 2005  Paul Mundt
   8  *
   9  * FRQCR parsing hacked out of arch/sh/kernel/time.c
  10  *
  11  *  Copyright (C) 1999  Tetsuya Okada & Niibe Yutaka
  12  *  Copyright (C) 2000  Philipp Rumpf <prumpf@tux.org>
  13  *  Copyright (C) 2002, 2003, 2004  Paul Mundt
  14  *  Copyright (C) 2002  M. R. Brown  <mrbrown@linux-sh.org>
  15  */
  16 #include <linux/init.h>
  17 #include <linux/kernel.h>
  18 #include <asm/clock.h>
  19 #include <asm/freq.h>
  20 #include <asm/io.h>
  21
  22 static int stc_multipliers[] = { 1, 2, 3, 4, 6, 1, 1, 1 };
  23 static int ifc_divisors[]    = { 1, 2, 3, 4, 1, 1, 1, 1 };
  24 static int pfc_divisors[]    = { 1, 2, 3, 4, 6, 1, 1, 1 };
  25
  26 static void master_clk_init(struct clk *clk)
  27 {
  28         int frqcr = __raw_readw(FRQCR);
  29         int idx = ((frqcr & 0x2000) >> 11) | (frqcr & 0x0003);
  30
  31         clk->rate *= pfc_divisors[idx];
  32 }
  33
  34 static struct sh_clk_ops sh3_master_clk_ops = {
  35         .init           = master_clk_init,
  36 };
  37
  38 static unsigned long module_clk_recalc(struct clk *clk)
  39 {
  40         int frqcr = __raw_readw(FRQCR);
  41         int idx = ((frqcr & 0x2000) >> 11) | (frqcr & 0x0003);
  42
  43         return clk->parent->rate / pfc_divisors[idx];
  44 }
  45
  46 static struct sh_clk_ops sh3_module_clk_ops = {
  47         .recalc         = module_clk_recalc,
  48 };
  49
  50 static unsigned long bus_clk_recalc(struct clk *clk)
  51 {
  52         int frqcr = __raw_readw(FRQCR);
  53         int idx = ((frqcr & 0x8000) >> 13) | ((frqcr & 0x0030) >> 4);
  54
  55         return clk->parent->rate / stc_multipliers[idx];
  56 }
  57
  58 static struct sh_clk_ops sh3_bus_clk_ops = {
  59         .recalc         = bus_clk_recalc,
  60 };
  61
  62 static unsigned long cpu_clk_recalc(struct clk *clk)
  63 {
  64         int frqcr = __raw_readw(FRQCR);
  65         int idx = ((frqcr & 0x4000) >> 12) | ((frqcr & 0x000c) >> 2);
  66
  67         return clk->parent->rate / ifc_divisors[idx];
  68 }
  69
  70 static struct sh_clk_ops sh3_cpu_clk_ops = {
  71         .recalc         = cpu_clk_recalc,
  72 };
  73
  74 static struct sh_clk_ops *sh3_clk_ops[] = {
  75         &sh3_master_clk_ops,
  76         &sh3_module_clk_ops,
  77         &sh3_bus_clk_ops,
  78         &sh3_cpu_clk_ops,
  79 };
  80
  81 void __init arch_init_clk_ops(struct sh_clk_ops **ops, int idx)
  82 {
  83         if (idx < ARRAY_SIZE(sh3_clk_ops))
  84                 *ops = sh3_clk_ops[idx];
  85 }
  86