1/* 2 * linux/arch/arm/mach-realview/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/clk.h> 17#include <linux/mutex.h> 18 19#include <asm/semaphore.h> 20#include <asm/hardware/icst307.h> 21 22#include "clock.h" 23 24static LIST_HEAD(clocks); 25static DEFINE_MUTEX(clocks_mutex); 26 27struct clk *clk_get(struct device *dev, const char *id) 28{ 29 struct clk *p, *clk = ERR_PTR(-ENOENT); 30 31 mutex_lock(&clocks_mutex); 32 list_for_each_entry(p, &clocks, node) { 33 if (strcmp(id, p->name) == 0 && try_module_get(p->owner)) { 34 clk = p; 35 break; 36 } 37 } 38 mutex_unlock(&clocks_mutex); 39 40 return clk; 41} 42EXPORT_SYMBOL(clk_get); 43 44void clk_put(struct clk *clk) 45{ 46 module_put(clk->owner); 47} 48EXPORT_SYMBOL(clk_put); 49 50int clk_enable(struct clk *clk) 51{ 52 return 0; 53} 54EXPORT_SYMBOL(clk_enable); 55 56void clk_disable(struct clk *clk) 57{ 58} 59EXPORT_SYMBOL(clk_disable); 60 61unsigned long clk_get_rate(struct clk *clk) 62{ 63 return clk->rate; 64} 65EXPORT_SYMBOL(clk_get_rate); 66 67long clk_round_rate(struct clk *clk, unsigned long rate) 68{ 69 return rate; 70} 71EXPORT_SYMBOL(clk_round_rate); 72 73int clk_set_rate(struct clk *clk, unsigned long rate) 74{ 75 int ret = -EIO; 76 77 if (clk->setvco) { 78 struct icst307_vco vco; 79 80 vco = icst307_khz_to_vco(clk->params, rate / 1000); 81 clk->rate = icst307_khz(clk->params, vco) * 1000; 82 83 printk("Clock %s: setting VCO reg params: S=%d R=%d V=%d\n", 84 clk->name, vco.s, vco.r, vco.v); 85 86 clk->setvco(clk, vco); 87 ret = 0; 88 } 89 return ret; 90} 91EXPORT_SYMBOL(clk_set_rate); 92 93/* 94 * These are fixed clocks. 95 */ 96static struct clk kmi_clk = { 97 .name = "KMIREFCLK", 98 .rate = 24000000, 99}; 100 101static struct clk uart_clk = { 102 .name = "UARTCLK", 103 .rate = 24000000, 104}; 105 106static struct clk mmci_clk = { 107 .name = "MCLK", 108 .rate = 33000000, 109}; 110 111int clk_register(struct clk *clk) 112{ 113 mutex_lock(&clocks_mutex); 114 list_add(&clk->node, &clocks); 115 mutex_unlock(&clocks_mutex); 116 return 0; 117} 118EXPORT_SYMBOL(clk_register); 119 120void clk_unregister(struct clk *clk) 121{ 122 mutex_lock(&clocks_mutex); 123 list_del(&clk->node); 124 mutex_unlock(&clocks_mutex); 125} 126EXPORT_SYMBOL(clk_unregister); 127 128static int __init clk_init(void) 129{ 130 clk_register(&kmi_clk); 131 clk_register(&uart_clk); 132 clk_register(&mmci_clk); 133 return 0; 134} 135arch_initcall(clk_init); 136