1/* 2 * File: arch/blackfin/mach-bf537/cpu.c 3 * Based on: 4 * Author: michael.kang@analog.com 5 * 6 * Created: 7 * Description: clock scaling for the bf537 8 * 9 * Modified: 10 * Copyright 2004-2006 Analog Devices Inc. 11 * 12 * Bugs: Enter bugs at http://blackfin.uclinux.org/ 13 * 14 * This program is free software; you can redistribute it and/or modify 15 * it under the terms of the GNU General Public License as published by 16 * the Free Software Foundation; either version 2 of the License, or 17 * (at your option) any later version. 18 * 19 * This program is distributed in the hope that it will be useful, 20 * but WITHOUT ANY WARRANTY; without even the implied warranty of 21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 22 * GNU General Public License for more details. 23 * 24 * You should have received a copy of the GNU General Public License 25 * along with this program; if not, see the file COPYING, or write 26 * to the Free Software Foundation, Inc., 27 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 28 */ 29 30#include <linux/kernel.h> 31#include <linux/types.h> 32#include <linux/init.h> 33#include <linux/cpufreq.h> 34#include <asm/dpmc.h> 35#include <linux/fs.h> 36#include <asm/bfin-global.h> 37 38/* CONFIG_CLKIN_HZ=11059200 */ 39#define VCO5 (CONFIG_CLKIN_HZ*45) /*497664000 */ 40#define VCO4 (CONFIG_CLKIN_HZ*36) /*398131200 */ 41#define VCO3 (CONFIG_CLKIN_HZ*27) /*298598400 */ 42#define VCO2 (CONFIG_CLKIN_HZ*18) /*199065600 */ 43#define VCO1 (CONFIG_CLKIN_HZ*9) /*99532800 */ 44#define VCO(x) VCO##x 45 46#define MFREQ(x) {VCO(x),VCO(x)/4},{VCO(x),VCO(x)/2},{VCO(x),VCO(x)} 47/* frequency */ 48static struct cpufreq_frequency_table bf537_freq_table[] = { 49 MFREQ(1), 50 MFREQ(3), 51 {VCO4, VCO4 / 2}, {VCO4, VCO4}, 52 MFREQ(5), 53 {0, CPUFREQ_TABLE_END}, 54}; 55 56/* 57 * dpmc_fops->ioctl() 58 * static int dpmc_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) 59 */ 60static int bf537_getfreq(unsigned int cpu) 61{ 62 unsigned long cclk_mhz; 63 64 /* The driver only support single cpu */ 65 if (cpu == 0) 66 dpmc_fops.ioctl(NULL, NULL, IOCTL_GET_CORECLOCK, &cclk_mhz); 67 else 68 cclk_mhz = -1; 69 70 return cclk_mhz; 71} 72 73static int bf537_target(struct cpufreq_policy *policy, 74 unsigned int target_freq, unsigned int relation) 75{ 76 unsigned long cclk_mhz; 77 unsigned long vco_mhz; 78 unsigned long flags; 79 unsigned int index; 80 struct cpufreq_freqs freqs; 81 82 if (cpufreq_frequency_table_target(policy, bf537_freq_table, target_freq, relation, &index)) 83 return -EINVAL; 84 85 cclk_mhz = bf537_freq_table[index].frequency; 86 vco_mhz = bf537_freq_table[index].index; 87 88 dpmc_fops.ioctl(NULL, NULL, IOCTL_CHANGE_FREQUENCY, &vco_mhz); 89 freqs.old = bf537_getfreq(0); 90 freqs.new = cclk_mhz; 91 freqs.cpu = 0; 92 93 pr_debug("cclk begin change to cclk %d,vco=%d,index=%d,target=%d,oldfreq=%d\n", 94 cclk_mhz, vco_mhz, index, target_freq, freqs.old); 95 96 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); 97 local_irq_save(flags); 98 dpmc_fops.ioctl(NULL, NULL, IOCTL_SET_CCLK, &cclk_mhz); 99 local_irq_restore(flags); 100 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); 101 102 vco_mhz = get_vco(); 103 cclk_mhz = get_cclk(); 104 return 0; 105} 106 107/* make sure that only the "userspace" governor is run -- anything else wouldn't make sense on 108 * this platform, anyway. 109 */ 110static int bf537_verify_speed(struct cpufreq_policy *policy) 111{ 112 return cpufreq_frequency_table_verify(policy, &bf537_freq_table); 113} 114 115static int __init __bf537_cpu_init(struct cpufreq_policy *policy) 116{ 117 if (policy->cpu != 0) 118 return -EINVAL; 119 120 policy->governor = CPUFREQ_DEFAULT_GOVERNOR; 121 122 policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; 123 /*Now ,only support one cpu */ 124 policy->cur = bf537_getfreq(0); 125 cpufreq_frequency_table_get_attr(bf537_freq_table, policy->cpu); 126 return cpufreq_frequency_table_cpuinfo(policy, bf537_freq_table); 127} 128 129static struct freq_attr *bf537_freq_attr[] = { 130 &cpufreq_freq_attr_scaling_available_freqs, 131 NULL, 132}; 133 134static struct cpufreq_driver bf537_driver = { 135 .verify = bf537_verify_speed, 136 .target = bf537_target, 137 .get = bf537_getfreq, 138 .init = __bf537_cpu_init, 139 .name = "bf537", 140 .owner = THIS_MODULE, 141 .attr = bf537_freq_attr, 142}; 143 144static int __init bf537_cpu_init(void) 145{ 146 return cpufreq_register_driver(&bf537_driver); 147} 148 149static void __exit bf537_cpu_exit(void) 150{ 151 cpufreq_unregister_driver(&bf537_driver); 152} 153 154MODULE_AUTHOR("Mickael Kang"); 155MODULE_DESCRIPTION("cpufreq driver for BF537 CPU"); 156MODULE_LICENSE("GPL"); 157 158module_init(bf537_cpu_init); 159module_exit(bf537_cpu_exit); 160