1/* 2 * linux/arch/arm/mach-versatile/clock.c 3 * 4 * Copyright (C) 2004 ARM Limited. 5 * Written by Deep Blue Solutions Limited. 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 */ 11#include <linux/module.h> 12#include <linux/kernel.h> 13#include <linux/list.h> 14#include <linux/errno.h> 15#include <linux/err.h> 16#include <linux/string.h> 17#include <linux/clk.h> 18#include <linux/mutex.h> 19 20#include <asm/semaphore.h> 21#include <asm/hardware/icst307.h> 22 23#include "clock.h" 24 25static LIST_HEAD(clocks); 26static DEFINE_MUTEX(clocks_mutex); 27 28struct clk *clk_get(struct device *dev, const char *id) 29{ 30 struct clk *p, *clk = ERR_PTR(-ENOENT); 31 32 mutex_lock(&clocks_mutex); 33 list_for_each_entry(p, &clocks, node) { 34 if (strcmp(id, p->name) == 0 && try_module_get(p->owner)) { 35 clk = p; 36 break; 37 } 38 } 39 mutex_unlock(&clocks_mutex); 40 41 return clk; 42} 43EXPORT_SYMBOL(clk_get); 44 45void clk_put(struct clk *clk) 46{ 47 module_put(clk->owner); 48} 49EXPORT_SYMBOL(clk_put); 50 51int clk_enable(struct clk *clk) 52{ 53 return 0; 54} 55EXPORT_SYMBOL(clk_enable); 56 57void clk_disable(struct clk *clk) 58{ 59} 60EXPORT_SYMBOL(clk_disable); 61 62unsigned long clk_get_rate(struct clk *clk) 63{ 64 return clk->rate; 65} 66EXPORT_SYMBOL(clk_get_rate); 67 68long clk_round_rate(struct clk *clk, unsigned long rate) 69{ 70 return rate; 71} 72EXPORT_SYMBOL(clk_round_rate); 73 74int clk_set_rate(struct clk *clk, unsigned long rate) 75{ 76 int ret = -EIO; 77 78 if (clk->setvco) { 79 struct icst307_vco vco; 80 81 vco = icst307_khz_to_vco(clk->params, rate / 1000); 82 clk->rate = icst307_khz(clk->params, vco) * 1000; 83 84 printk("Clock %s: setting VCO reg params: S=%d R=%d V=%d\n", 85 clk->name, vco.s, vco.r, vco.v); 86 87 clk->setvco(clk, vco); 88 ret = 0; 89 } 90 return ret; 91} 92EXPORT_SYMBOL(clk_set_rate); 93 94/* 95 * These are fixed clocks. 96 */ 97static struct clk kmi_clk = { 98 .name = "KMIREFCLK", 99 .rate = 24000000, 100}; 101 102static struct clk uart_clk = { 103 .name = "UARTCLK", 104 .rate = 24000000, 105}; 106 107static struct clk mmci_clk = { 108 .name = "MCLK", 109 .rate = 33000000, 110}; 111 112int clk_register(struct clk *clk) 113{ 114 mutex_lock(&clocks_mutex); 115 list_add(&clk->node, &clocks); 116 mutex_unlock(&clocks_mutex); 117 return 0; 118} 119EXPORT_SYMBOL(clk_register); 120 121void clk_unregister(struct clk *clk) 122{ 123 mutex_lock(&clocks_mutex); 124 list_del(&clk->node); 125 mutex_unlock(&clocks_mutex); 126} 127EXPORT_SYMBOL(clk_unregister); 128 129static int __init clk_init(void) 130{ 131 clk_register(&kmi_clk); 132 clk_register(&uart_clk); 133 clk_register(&mmci_clk); 134 return 0; 135} 136arch_initcall(clk_init); 137