diff options
Diffstat (limited to 'arch/blackfin/mach-bf548/cpu.c')
| -rw-r--r-- | arch/blackfin/mach-bf548/cpu.c | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/arch/blackfin/mach-bf548/cpu.c b/arch/blackfin/mach-bf548/cpu.c new file mode 100644 index 00000000000..4298a3ccfbf --- /dev/null +++ b/arch/blackfin/mach-bf548/cpu.c @@ -0,0 +1,159 @@ +/* + * File: arch/blackfin/mach-bf548/cpu.c + * Based on: + * Author: + * + * Created: + * Description: clock scaling for the bf54x + * + * Modified: + * Copyright 2004-2007 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=25000000 */ +#define VCO5 (CONFIG_CLKIN_HZ*45) +#define VCO4 (CONFIG_CLKIN_HZ*36) +#define VCO3 (CONFIG_CLKIN_HZ*27) +#define VCO2 (CONFIG_CLKIN_HZ*18) +#define VCO1 (CONFIG_CLKIN_HZ*9) +#define VCO(x) VCO##x + +#define MFREQ(x) {VCO(x),VCO(x)/4},{VCO(x),VCO(x)/2},{VCO(x),VCO(x)} +/* frequency */ +static struct cpufreq_frequency_table bf548_freq_table[] = { + MFREQ(1), + MFREQ(3), + {VCO4, VCO4 / 2}, {VCO4, VCO4}, + MFREQ(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 bf548_getfreq(unsigned int cpu) +{ + unsigned long cclk_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 bf548_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; + struct cpufreq_freqs freqs; + + if (cpufreq_frequency_table_target(policy, bf548_freq_table, target_freq, relation, &index)) + return -EINVAL; + + cclk_mhz = bf548_freq_table[index].frequency; + vco_mhz = bf548_freq_table[index].index; + + dpmc_fops.ioctl(NULL, NULL, IOCTL_CHANGE_FREQUENCY, &vco_mhz); + freqs.old = bf548_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 bf548_verify_speed(struct cpufreq_policy *policy) +{ + return cpufreq_frequency_table_verify(policy, &bf548_freq_table); +} + +static int __init __bf548_cpu_init(struct cpufreq_policy *policy) +{ + if (policy->cpu != 0) + return -EINVAL; + + policy->governor = CPUFREQ_DEFAULT_GOVERNOR; + + policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; + /*Now ,only support one cpu */ + policy->cur = bf548_getfreq(0); + cpufreq_frequency_table_get_attr(bf548_freq_table, policy->cpu); + return cpufreq_frequency_table_cpuinfo(policy, bf548_freq_table); +} + +static struct freq_attr *bf548_freq_attr[] = { + &cpufreq_freq_attr_scaling_available_freqs, + NULL, +}; + +static struct cpufreq_driver bf548_driver = { + .verify = bf548_verify_speed, + .target = bf548_target, + .get = bf548_getfreq, + .init = __bf548_cpu_init, + .name = "bf548", + .owner = THIS_MODULE, + .attr = bf548_freq_attr, +}; + +static int __init bf548_cpu_init(void) +{ + return cpufreq_register_driver(&bf548_driver); +} + +static void __exit bf548_cpu_exit(void) +{ + cpufreq_unregister_driver(&bf548_driver); +} + +MODULE_AUTHOR("Mickael Kang"); +MODULE_DESCRIPTION("cpufreq driver for BF548 CPU"); +MODULE_LICENSE("GPL"); + +module_init(bf548_cpu_init); +module_exit(bf548_cpu_exit); |