/* * File: arch/blackfin/mach-bf533/cpu.c * Based on: * Author: michael.kang@analog.com * * Created: * Description: clock scaling for the bf533 * * Modified: * Copyright 2004-2006 Analog Devices Inc. * * Bugs: Enter bugs at http://blackfin.uclinux.org/ * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, see the file COPYING, or write * to the Free Software Foundation, Inc., * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ #include <linux/kernel.h> #include <linux/types.h> #include <linux/init.h> #include <linux/cpufreq.h> #include <asm/dpmc.h> #include <linux/fs.h> #include <asm/bfin-global.h> /* CONFIG_CLKIN_HZ=11059200 */ #define VCO5 (CONFIG_CLKIN_HZ*45) /*497664000 */ #define VCO4 (CONFIG_CLKIN_HZ*36) /*398131200 */ #define VCO3 (CONFIG_CLKIN_HZ*27) /*298598400 */ #define VCO2 (CONFIG_CLKIN_HZ*18) /*199065600 */ #define VCO1 (CONFIG_CLKIN_HZ*9) /*99532800 */ #define VCO(x) VCO##x #define FREQ(x) {VCO(x),VCO(x)/4},{VCO(x),VCO(x)/2},{VCO(x),VCO(x)} /* frequency */ static struct cpufreq_frequency_table bf533_freq_table[] = { FREQ(1), FREQ(3), {VCO4, VCO4 / 2}, {VCO4, VCO4}, FREQ(5), {0, CPUFREQ_TABLE_END}, }; /* * dpmc_fops->ioctl() * static int dpmc_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) */ static int bf533_getfreq(unsigned int cpu) { unsigned long cclk_mhz, vco_mhz; /* The driver only support single cpu */ if (cpu == 0) dpmc_fops.ioctl(NULL, NULL, IOCTL_GET_CORECLOCK, &cclk_mhz); else cclk_mhz = -1; return cclk_mhz; } static int bf533_target(struct cpufreq_policy *policy, unsigned int target_freq, unsigned int relation) { unsigned long cclk_mhz; unsigned long vco_mhz; unsigned long flags; unsigned int index, vco_index; int i; struct cpufreq_freqs freqs; if (cpufreq_frequency_table_target(policy, bf533_freq_table, target_freq, relation, &index)) return -EINVAL; cclk_mhz = bf533_freq_table[index].frequency; vco_mhz = bf533_freq_table[index].index; dpmc_fops.ioctl(NULL, NULL, IOCTL_CHANGE_FREQUENCY, &vco_mhz); freqs.old = bf533_getfreq(0); freqs.new = cclk_mhz; freqs.cpu = 0; pr_debug("cclk begin change to cclk %d,vco=%d,index=%d,target=%d,oldfreq=%d\n", cclk_mhz, vco_mhz, index, target_freq, freqs.old); cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); local_irq_save(flags); dpmc_fops.ioctl(NULL, NULL, IOCTL_SET_CCLK, &cclk_mhz); local_irq_restore(flags); cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); vco_mhz = get_vco(); cclk_mhz = get_cclk(); return 0; } /* make sure that only the "userspace" governor is run -- anything else wouldn't make sense on * this platform, anyway. */ static int bf533_verify_speed(struct cpufreq_policy *policy) { return cpufreq_frequency_table_verify(policy, &bf533_freq_table); } static int __init __bf533_cpu_init(struct cpufreq_policy *policy) { int result; if (policy->cpu != 0) return -EINVAL; policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; /*Now ,only support one cpu */ policy->cur = bf533_getfreq(0); cpufreq_frequency_table_get_attr(bf533_freq_table, policy->cpu); return cpufreq_frequency_table_cpuinfo(policy, bf533_freq_table); } static struct freq_attr *bf533_freq_attr[] = { &cpufreq_freq_attr_scaling_available_freqs, NULL, }; static struct cpufreq_driver bf533_driver = { .verify = bf533_verify_speed, .target = bf533_target, .get = bf533_getfreq, .init = __bf533_cpu_init, .name = "bf533", .owner = THIS_MODULE, .attr = bf533_freq_attr, }; static int __init bf533_cpu_init(void) { return cpufreq_register_driver(&bf533_driver); } static void __exit bf533_cpu_exit(void) { cpufreq_unregister_driver(&bf533_driver); } MODULE_AUTHOR("Mickael Kang"); MODULE_DESCRIPTION("cpufreq driver for BF533 CPU"); MODULE_LICENSE("GPL"); module_init(bf533_cpu_init); module_exit(bf533_cpu_exit);