160 lines
4.4 KiB
C
160 lines
4.4 KiB
C
/*
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* File: arch/blackfin/mach-bf537/cpu.c
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* Based on:
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* Author: michael.kang@analog.com
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*
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* Created:
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* Description: clock scaling for the bf537
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*
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* Modified:
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* Copyright 2004-2006 Analog Devices Inc.
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*
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* Bugs: Enter bugs at http://blackfin.uclinux.org/
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, see the file COPYING, or write
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* to the Free Software Foundation, Inc.,
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* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include <linux/kernel.h>
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#include <linux/types.h>
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#include <linux/init.h>
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#include <linux/cpufreq.h>
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#include <asm/dpmc.h>
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#include <linux/fs.h>
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#include <asm/bfin-global.h>
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/* CONFIG_CLKIN_HZ=11059200 */
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#define VCO5 (CONFIG_CLKIN_HZ*45) /*497664000 */
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#define VCO4 (CONFIG_CLKIN_HZ*36) /*398131200 */
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#define VCO3 (CONFIG_CLKIN_HZ*27) /*298598400 */
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#define VCO2 (CONFIG_CLKIN_HZ*18) /*199065600 */
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#define VCO1 (CONFIG_CLKIN_HZ*9) /*99532800 */
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#define VCO(x) VCO##x
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#define MFREQ(x) {VCO(x),VCO(x)/4},{VCO(x),VCO(x)/2},{VCO(x),VCO(x)}
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/* frequency */
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static struct cpufreq_frequency_table bf537_freq_table[] = {
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MFREQ(1),
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MFREQ(3),
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{VCO4, VCO4 / 2}, {VCO4, VCO4},
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MFREQ(5),
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{0, CPUFREQ_TABLE_END},
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};
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/*
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* dpmc_fops->ioctl()
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* static int dpmc_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
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*/
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static int bf537_getfreq(unsigned int cpu)
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{
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unsigned long cclk_mhz;
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/* The driver only support single cpu */
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if (cpu == 0)
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dpmc_fops.ioctl(NULL, NULL, IOCTL_GET_CORECLOCK, &cclk_mhz);
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else
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cclk_mhz = -1;
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return cclk_mhz;
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}
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static int bf537_target(struct cpufreq_policy *policy,
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unsigned int target_freq, unsigned int relation)
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{
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unsigned long cclk_mhz;
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unsigned long vco_mhz;
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unsigned long flags;
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unsigned int index;
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struct cpufreq_freqs freqs;
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if (cpufreq_frequency_table_target(policy, bf537_freq_table, target_freq, relation, &index))
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return -EINVAL;
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cclk_mhz = bf537_freq_table[index].frequency;
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vco_mhz = bf537_freq_table[index].index;
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dpmc_fops.ioctl(NULL, NULL, IOCTL_CHANGE_FREQUENCY, &vco_mhz);
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freqs.old = bf537_getfreq(0);
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freqs.new = cclk_mhz;
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freqs.cpu = 0;
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pr_debug("cclk begin change to cclk %d,vco=%d,index=%d,target=%d,oldfreq=%d\n",
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cclk_mhz, vco_mhz, index, target_freq, freqs.old);
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cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
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local_irq_save(flags);
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dpmc_fops.ioctl(NULL, NULL, IOCTL_SET_CCLK, &cclk_mhz);
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local_irq_restore(flags);
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cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
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vco_mhz = get_vco();
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cclk_mhz = get_cclk();
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return 0;
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}
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/* make sure that only the "userspace" governor is run -- anything else wouldn't make sense on
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* this platform, anyway.
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*/
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static int bf537_verify_speed(struct cpufreq_policy *policy)
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{
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return cpufreq_frequency_table_verify(policy, &bf537_freq_table);
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}
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static int __init __bf537_cpu_init(struct cpufreq_policy *policy)
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{
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if (policy->cpu != 0)
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return -EINVAL;
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policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
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policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
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/*Now ,only support one cpu */
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policy->cur = bf537_getfreq(0);
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cpufreq_frequency_table_get_attr(bf537_freq_table, policy->cpu);
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return cpufreq_frequency_table_cpuinfo(policy, bf537_freq_table);
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}
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static struct freq_attr *bf537_freq_attr[] = {
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&cpufreq_freq_attr_scaling_available_freqs,
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NULL,
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};
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static struct cpufreq_driver bf537_driver = {
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.verify = bf537_verify_speed,
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.target = bf537_target,
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.get = bf537_getfreq,
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.init = __bf537_cpu_init,
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.name = "bf537",
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.owner = THIS_MODULE,
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.attr = bf537_freq_attr,
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};
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static int __init bf537_cpu_init(void)
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{
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return cpufreq_register_driver(&bf537_driver);
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}
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static void __exit bf537_cpu_exit(void)
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{
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cpufreq_unregister_driver(&bf537_driver);
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}
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MODULE_AUTHOR("Mickael Kang");
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MODULE_DESCRIPTION("cpufreq driver for BF537 CPU");
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MODULE_LICENSE("GPL");
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module_init(bf537_cpu_init);
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module_exit(bf537_cpu_exit);
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