release/src-rt-6.x/linux/linux-2.6/arch/sh/kernel/cpu/sh4a/clock-sh7785.c

   1 /*
   2  * arch/sh/kernel/cpu/sh4a/clock-sh7785.c
   3  *
   4  * SH7785 support for the clock framework
   5  *
   6  *  Copyright (C) 2007  Paul Mundt
   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 <asm/clock.h>
  15 #include <asm/freq.h>
  16 #include <asm/io.h>
  17
  18 static int ifc_divisors[] = { 1, 2, 4, 6 };
  19 static int ufc_divisors[] = { 1, 1, 4, 6 };
  20 static int sfc_divisors[] = { 1, 1, 4, 6 };
  21 static int bfc_divisors[] = { 1, 1, 1, 1, 1, 12, 16, 18,
  22                              24, 32, 36, 48, 1, 1, 1, 1 };
  23 static int mfc_divisors[] = { 1, 1, 4, 6 };
  24 static int pfc_divisors[] = { 1, 1, 1, 1, 1, 1, 1, 18,
  25                               24, 32, 36, 48, 1, 1, 1, 1 };
  26
  27 static void master_clk_init(struct clk *clk)
  28 {
  29         clk->rate *= 36;
  30 }
  31
  32 static struct clk_ops sh7785_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(FRQMR1) & 0x000f);
  39         clk->rate = clk->parent->rate / pfc_divisors[idx];
  40 }
  41
  42 static struct clk_ops sh7785_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(FRQMR1) >> 16) & 0x000f);
  49         clk->rate = clk->parent->rate / bfc_divisors[idx];
  50 }
  51
  52 static struct clk_ops sh7785_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(FRQMR1) >> 28) & 0x0003);
  59         clk->rate = clk->parent->rate / ifc_divisors[idx];
  60 }
  61
  62 static struct clk_ops sh7785_cpu_clk_ops = {
  63         .recalc         = cpu_clk_recalc,
  64 };
  65
  66 static struct clk_ops *sh7785_clk_ops[] = {
  67         &sh7785_master_clk_ops,
  68         &sh7785_module_clk_ops,
  69         &sh7785_bus_clk_ops,
  70         &sh7785_cpu_clk_ops,
  71 };
  72
  73 void __init arch_init_clk_ops(struct clk_ops **ops, int idx)
  74 {
  75         if (idx < ARRAY_SIZE(sh7785_clk_ops))
  76                 *ops = sh7785_clk_ops[idx];
  77 }
  78
  79 static void shyway_clk_recalc(struct clk *clk)
  80 {
  81         int idx = ((ctrl_inl(FRQMR1) >> 20) & 0x0003);
  82         clk->rate = clk->parent->rate / sfc_divisors[idx];
  83 }
  84
  85 static struct clk_ops sh7785_shyway_clk_ops = {
  86         .recalc         = shyway_clk_recalc,
  87 };
  88
  89 static struct clk sh7785_shyway_clk = {
  90         .name           = "shyway_clk",
  91         .flags          = CLK_ALWAYS_ENABLED,
  92         .ops            = &sh7785_shyway_clk_ops,
  93 };
  94
  95 static void ddr_clk_recalc(struct clk *clk)
  96 {
  97         int idx = ((ctrl_inl(FRQMR1) >> 12) & 0x0003);
  98         clk->rate = clk->parent->rate / mfc_divisors[idx];
  99 }
 100
 101 static struct clk_ops sh7785_ddr_clk_ops = {
 102         .recalc         = ddr_clk_recalc,
 103 };
 104
 105 static struct clk sh7785_ddr_clk = {
 106         .name           = "ddr_clk",
 107         .flags          = CLK_ALWAYS_ENABLED,
 108         .ops            = &sh7785_ddr_clk_ops,
 109 };
 110
 111 static void ram_clk_recalc(struct clk *clk)
 112 {
 113         int idx = ((ctrl_inl(FRQMR1) >> 24) & 0x0003);
 114         clk->rate = clk->parent->rate / ufc_divisors[idx];
 115 }
 116
 117 static struct clk_ops sh7785_ram_clk_ops = {
 118         .recalc         = ram_clk_recalc,
 119 };
 120
 121 static struct clk sh7785_ram_clk = {
 122         .name           = "ram_clk",
 123         .flags          = CLK_ALWAYS_ENABLED,
 124         .ops            = &sh7785_ram_clk_ops,
 125 };
 126
 127 /*
 128  * Additional SH7785-specific on-chip clocks that aren't already part of the
 129  * clock framework
 130  */
 131 static struct clk *sh7785_onchip_clocks[] = {
 132         &sh7785_shyway_clk,
 133         &sh7785_ddr_clk,
 134         &sh7785_ram_clk,
 135 };
 136
 137 static int __init sh7785_clk_init(void)
 138 {
 139         struct clk *clk = clk_get(NULL, "master_clk");
 140         int i;
 141
 142         for (i = 0; i < ARRAY_SIZE(sh7785_onchip_clocks); i++) {
 143                 struct clk *clkp = sh7785_onchip_clocks[i];
 144
 145                 clkp->parent = clk;
 146                 clk_register(clkp);
 147                 clk_enable(clkp);
 148         }
 149
 150         /*
 151          * Now that we have the rest of the clocks registered, we need to
 152          * force the parent clock to propagate so that these clocks will
 153          * automatically figure out their rate. We cheat by handing the
 154          * parent clock its current rate and forcing child propagation.
 155          */
 156         clk_set_rate(clk, clk_get_rate(clk));
 157
 158         clk_put(clk);
 159
 160         return 0;
 161 }
 162 arch_initcall(sh7785_clk_init);