arch/sh/kernel/cpu/sh4a/clock-sh7757.c

   1 /*
   2  * arch/sh/kernel/cpu/sh4/clock-sh7757.c
   3  *
   4  * SH7757 support for the clock framework
   5  *
   6  *  Copyright (C) 2009  Renesas Solutions Corp.
   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 <linux/io.h>
  15 #include <asm/clock.h>
  16 #include <asm/freq.h>
  17
  18 static int ifc_divisors[] = { 2, 1, 4, 1, 1, 8, 1, 1,
  19                               16, 1, 1, 32, 1, 1, 1, 1 };
  20 static int sfc_divisors[] = { 2, 1, 4, 1, 1, 8, 1, 1,
  21                               16, 1, 1, 32, 1, 1, 1, 1 };
  22 static int bfc_divisors[] = { 2, 1, 4, 1, 1, 8, 1, 1,
  23                               16, 1, 1, 32, 1, 1, 1, 1 };
  24 static int p1fc_divisors[] = { 2, 1, 4, 1, 1, 8, 1, 1,
  25                                16, 1, 1, 32, 1, 1, 1, 1 };
  26
  27 static void master_clk_init(struct clk *clk)
  28 {
  29         clk->rate = CONFIG_SH_PCLK_FREQ * 16;
  30 }
  31
  32 static struct clk_ops sh7757_master_clk_ops = {
  33         .init           = master_clk_init,
  34 };
  35
  36 static void module_clk_recalc(struct clk *clk)
  37 {
  38         int idx = ctrl_inl(FRQCR) & 0x0000000f;
  39         clk->rate = clk->parent->rate / p1fc_divisors[idx];
  40 }
  41
  42 static struct clk_ops sh7757_module_clk_ops = {
  43         .recalc         = module_clk_recalc,
  44 };
  45
  46 static void bus_clk_recalc(struct clk *clk)
  47 {
  48         int idx = (ctrl_inl(FRQCR) >> 8) & 0x0000000f;
  49         clk->rate = clk->parent->rate / bfc_divisors[idx];
  50 }
  51
  52 static struct clk_ops sh7757_bus_clk_ops = {
  53         .recalc         = bus_clk_recalc,
  54 };
  55
  56 static void cpu_clk_recalc(struct clk *clk)
  57 {
  58         int idx = (ctrl_inl(FRQCR) >> 20) & 0x0000000f;
  59         clk->rate = clk->parent->rate / ifc_divisors[idx];
  60 }
  61
  62 static struct clk_ops sh7757_cpu_clk_ops = {
  63         .recalc         = cpu_clk_recalc,
  64 };
  65
  66 static struct clk_ops *sh7757_clk_ops[] = {
  67         &sh7757_master_clk_ops,
  68         &sh7757_module_clk_ops,
  69         &sh7757_bus_clk_ops,
  70         &sh7757_cpu_clk_ops,
  71 };
  72
  73 void __init arch_init_clk_ops(struct clk_ops **ops, int idx)
  74 {
  75         if (idx < ARRAY_SIZE(sh7757_clk_ops))
  76                 *ops = sh7757_clk_ops[idx];
  77 }
  78
  79 static void shyway_clk_recalc(struct clk *clk)
  80 {
  81         int idx = (ctrl_inl(FRQCR) >> 12) & 0x0000000f;
  82         clk->rate = clk->parent->rate / sfc_divisors[idx];
  83 }
  84
  85 static struct clk_ops sh7757_shyway_clk_ops = {
  86         .recalc         = shyway_clk_recalc,
  87 };
  88
  89 static struct clk sh7757_shyway_clk = {
  90         .name           = "shyway_clk",
  91         .flags          = CLK_ENABLE_ON_INIT,
  92         .ops            = &sh7757_shyway_clk_ops,
  93 };
  94
  95 /*
  96  * Additional sh7757-specific on-chip clocks that aren't already part of the
  97  * clock framework
  98  */
  99 static struct clk *sh7757_onchip_clocks[] = {
 100         &sh7757_shyway_clk,
 101 };
 102
 103 static int __init sh7757_clk_init(void)
 104 {
 105         struct clk *clk = clk_get(NULL, "master_clk");
 106         int i;
 107
 108         for (i = 0; i < ARRAY_SIZE(sh7757_onchip_clocks); i++) {
 109                 struct clk *clkp = sh7757_onchip_clocks[i];
 110
 111                 clkp->parent = clk;
 112                 clk_register(clkp);
 113                 clk_enable(clkp);
 114         }
 115
 116         /*
 117          * Now that we have the rest of the clocks registered, we need to
 118          * force the parent clock to propagate so that these clocks will
 119          * automatically figure out their rate. We cheat by handing the
 120          * parent clock its current rate and forcing child propagation.
 121          */
 122         clk_set_rate(clk, clk_get_rate(clk));
 123
 124         clk_put(clk);
 125
 126         return 0;
 127 }
 128
 129 arch_initcall(sh7757_clk_init);
 130