1 /* 2 * arch/sh/kernel/cpu/sh4/clock-shx3.c 3 * 4 * SH-X3 support for the clock framework 5 * 6 * Copyright (C) 2006-2007 Renesas Technology Corp. 7 * Copyright (C) 2006-2007 Renesas Solutions Corp. 8 * Copyright (C) 2006-2007 Paul Mundt 9 * 10 * This file is subject to the terms and conditions of the GNU General Public 11 * License. See the file "COPYING" in the main directory of this archive 12 * for more details. 13 */ 14 #include <linux/init.h> 15 #include <linux/kernel.h> 16 #include <asm/clock.h> 17 #include <asm/freq.h> 18 #include <asm/io.h> 19 20 static int ifc_divisors[] = { 1, 2, 4 ,6 }; 21 static int bfc_divisors[] = { 1, 1, 1, 1, 1, 12, 16, 18, 24, 32, 36, 48 }; 22 static int pfc_divisors[] = { 1, 1, 1, 1, 1, 1, 1, 18, 24, 32, 36, 48 }; 23 static int cfc_divisors[] = { 1, 1, 4, 6 }; 24 25 #define IFC_POS 28 26 #define IFC_MSK 0x0003 27 #define BFC_MSK 0x000f 28 #define PFC_MSK 0x000f 29 #define CFC_MSK 0x0003 30 #define BFC_POS 16 31 #define PFC_POS 0 32 #define CFC_POS 20 33 34 static void master_clk_init(struct clk *clk) 35 { 36 clk->rate *= pfc_divisors[(ctrl_inl(FRQCR) >> PFC_POS) & PFC_MSK]; 37 } 38 39 static struct clk_ops shx3_master_clk_ops = { 40 .init = master_clk_init, 41 }; 42 43 static void module_clk_recalc(struct clk *clk) 44 { 45 int idx = ((ctrl_inl(FRQCR) >> PFC_POS) & PFC_MSK); 46 clk->rate = clk->parent->rate / pfc_divisors[idx]; 47 } 48 49 static struct clk_ops shx3_module_clk_ops = { 50 .recalc = module_clk_recalc, 51 }; 52 53 static void bus_clk_recalc(struct clk *clk) 54 { 55 int idx = ((ctrl_inl(FRQCR) >> BFC_POS) & BFC_MSK); 56 clk->rate = clk->parent->rate / bfc_divisors[idx]; 57 } 58 59 static struct clk_ops shx3_bus_clk_ops = { 60 .recalc = bus_clk_recalc, 61 }; 62 63 static void cpu_clk_recalc(struct clk *clk) 64 { 65 int idx = ((ctrl_inl(FRQCR) >> IFC_POS) & IFC_MSK); 66 clk->rate = clk->parent->rate / ifc_divisors[idx]; 67 } 68 69 static struct clk_ops shx3_cpu_clk_ops = { 70 .recalc = cpu_clk_recalc, 71 }; 72 73 static struct clk_ops *shx3_clk_ops[] = { 74 &shx3_master_clk_ops, 75 &shx3_module_clk_ops, 76 &shx3_bus_clk_ops, 77 &shx3_cpu_clk_ops, 78 }; 79 80 void __init arch_init_clk_ops(struct clk_ops **ops, int idx) 81 { 82 if (idx < ARRAY_SIZE(shx3_clk_ops)) 83 *ops = shx3_clk_ops[idx]; 84 } 85 86 static void shyway_clk_recalc(struct clk *clk) 87 { 88 int idx = ((ctrl_inl(FRQCR) >> CFC_POS) & CFC_MSK); 89 clk->rate = clk->parent->rate / cfc_divisors[idx]; 90 } 91 92 static struct clk_ops shx3_shyway_clk_ops = { 93 .recalc = shyway_clk_recalc, 94 }; 95 96 static struct clk shx3_shyway_clk = { 97 .name = "shyway_clk", 98 .flags = CLK_ALWAYS_ENABLED, 99 .ops = &shx3_shyway_clk_ops, 100 }; 101 102 /* 103 * Additional SHx3-specific on-chip clocks that aren't already part of the 104 * clock framework 105 */ 106 static struct clk *shx3_onchip_clocks[] = { 107 &shx3_shyway_clk, 108 }; 109 110 static int __init shx3_clk_init(void) 111 { 112 struct clk *clk = clk_get(NULL, "master_clk"); 113 int i; 114 115 for (i = 0; i < ARRAY_SIZE(shx3_onchip_clocks); i++) { 116 struct clk *clkp = shx3_onchip_clocks[i]; 117 118 clkp->parent = clk; 119 clk_register(clkp); 120 clk_enable(clkp); 121 } 122 123 /* 124 * Now that we have the rest of the clocks registered, we need to 125 * force the parent clock to propagate so that these clocks will 126 * automatically figure out their rate. We cheat by handing the 127 * parent clock its current rate and forcing child propagation. 128 */ 129 clk_set_rate(clk, clk_get_rate(clk)); 130 131 clk_put(clk); 132 133 return 0; 134 } 135 arch_initcall(shx3_clk_init); 136