1 /* 2 * arch/sh/kernel/cpu/sh3/clock-sh3.c 3 * 4 * Generic SH-3 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 static int stc_multipliers[] = { 1, 2, 3, 4, 6, 1, 1, 1 }; 26 static int ifc_divisors[] = { 1, 2, 3, 4, 1, 1, 1, 1 }; 27 static int pfc_divisors[] = { 1, 2, 3, 4, 6, 1, 1, 1 }; 28 29 static void master_clk_init(struct clk *clk) 30 { 31 int frqcr = __raw_readw(FRQCR); 32 int idx = ((frqcr & 0x2000) >> 11) | (frqcr & 0x0003); 33 34 clk->rate *= pfc_divisors[idx]; 35 } 36 37 static struct sh_clk_ops sh3_master_clk_ops = { 38 .init = master_clk_init, 39 }; 40 41 static unsigned long module_clk_recalc(struct clk *clk) 42 { 43 int frqcr = __raw_readw(FRQCR); 44 int idx = ((frqcr & 0x2000) >> 11) | (frqcr & 0x0003); 45 46 return clk->parent->rate / pfc_divisors[idx]; 47 } 48 49 static struct sh_clk_ops sh3_module_clk_ops = { 50 .recalc = module_clk_recalc, 51 }; 52 53 static unsigned long bus_clk_recalc(struct clk *clk) 54 { 55 int frqcr = __raw_readw(FRQCR); 56 int idx = ((frqcr & 0x8000) >> 13) | ((frqcr & 0x0030) >> 4); 57 58 return clk->parent->rate / stc_multipliers[idx]; 59 } 60 61 static struct sh_clk_ops sh3_bus_clk_ops = { 62 .recalc = bus_clk_recalc, 63 }; 64 65 static unsigned long cpu_clk_recalc(struct clk *clk) 66 { 67 int frqcr = __raw_readw(FRQCR); 68 int idx = ((frqcr & 0x4000) >> 12) | ((frqcr & 0x000c) >> 2); 69 70 return clk->parent->rate / ifc_divisors[idx]; 71 } 72 73 static struct sh_clk_ops sh3_cpu_clk_ops = { 74 .recalc = cpu_clk_recalc, 75 }; 76 77 static struct sh_clk_ops *sh3_clk_ops[] = { 78 &sh3_master_clk_ops, 79 &sh3_module_clk_ops, 80 &sh3_bus_clk_ops, 81 &sh3_cpu_clk_ops, 82 }; 83 84 void __init arch_init_clk_ops(struct sh_clk_ops **ops, int idx) 85 { 86 if (idx < ARRAY_SIZE(sh3_clk_ops)) 87 *ops = sh3_clk_ops[idx]; 88 } 89 90