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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 | /* * Cpufreq driver for the loongson-2 processors * * The 2E revision of loongson processor not support this feature. * * Copyright (C) 2006 - 2008 Lemote Inc. & Institute of Computing Technology * Author: Yanhua, yanh@lemote.com * * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/cpufreq.h> #include <linux/module.h> #include <linux/err.h> #include <linux/sched.h> /* set_cpus_allowed() */ #include <linux/delay.h> #include <linux/platform_device.h> #include <asm/clock.h> #include <asm/idle.h> #include <asm/mach-loongson64/loongson.h> static uint nowait; static void (*saved_cpu_wait) (void); static int loongson2_cpu_freq_notifier(struct notifier_block *nb, unsigned long val, void *data); static struct notifier_block loongson2_cpufreq_notifier_block = { .notifier_call = loongson2_cpu_freq_notifier }; static int loongson2_cpu_freq_notifier(struct notifier_block *nb, unsigned long val, void *data) { if (val == CPUFREQ_POSTCHANGE) current_cpu_data.udelay_val = loops_per_jiffy; return 0; } /* * Here we notify other drivers of the proposed change and the final change. */ static int loongson2_cpufreq_target(struct cpufreq_policy *policy, unsigned int index) { unsigned int freq; freq = ((cpu_clock_freq / 1000) * loongson2_clockmod_table[index].driver_data) / 8; /* setting the cpu frequency */ clk_set_rate(policy->clk, freq * 1000); return 0; } static int loongson2_cpufreq_cpu_init(struct cpufreq_policy *policy) { struct clk *cpuclk; int i; unsigned long rate; int ret; cpuclk = clk_get(NULL, "cpu_clk"); if (IS_ERR(cpuclk)) { pr_err("couldn't get CPU clk\n"); return PTR_ERR(cpuclk); } rate = cpu_clock_freq / 1000; if (!rate) { clk_put(cpuclk); return -EINVAL; } /* clock table init */ for (i = 2; (loongson2_clockmod_table[i].frequency != CPUFREQ_TABLE_END); i++) loongson2_clockmod_table[i].frequency = (rate * i) / 8; ret = clk_set_rate(cpuclk, rate * 1000); if (ret) { clk_put(cpuclk); return ret; } policy->clk = cpuclk; return cpufreq_generic_init(policy, &loongson2_clockmod_table[0], 0); } static int loongson2_cpufreq_exit(struct cpufreq_policy *policy) { clk_put(policy->clk); return 0; } static struct cpufreq_driver loongson2_cpufreq_driver = { .name = "loongson2", .init = loongson2_cpufreq_cpu_init, .verify = cpufreq_generic_frequency_table_verify, .target_index = loongson2_cpufreq_target, .get = cpufreq_generic_get, .exit = loongson2_cpufreq_exit, .attr = cpufreq_generic_attr, }; static const struct platform_device_id platform_device_ids[] = { { .name = "loongson2_cpufreq", }, {} }; MODULE_DEVICE_TABLE(platform, platform_device_ids); static struct platform_driver platform_driver = { .driver = { .name = "loongson2_cpufreq", }, .id_table = platform_device_ids, }; /* * This is the simple version of Loongson-2 wait, Maybe we need do this in * interrupt disabled context. */ static DEFINE_SPINLOCK(loongson2_wait_lock); static void loongson2_cpu_wait(void) { unsigned long flags; u32 cpu_freq; spin_lock_irqsave(&loongson2_wait_lock, flags); cpu_freq = LOONGSON_CHIPCFG(0); LOONGSON_CHIPCFG(0) &= ~0x7; /* Put CPU into wait mode */ LOONGSON_CHIPCFG(0) = cpu_freq; /* Restore CPU state */ spin_unlock_irqrestore(&loongson2_wait_lock, flags); local_irq_enable(); } static int __init cpufreq_init(void) { int ret; /* Register platform stuff */ ret = platform_driver_register(&platform_driver); if (ret) return ret; pr_info("Loongson-2F CPU frequency driver\n"); cpufreq_register_notifier(&loongson2_cpufreq_notifier_block, CPUFREQ_TRANSITION_NOTIFIER); ret = cpufreq_register_driver(&loongson2_cpufreq_driver); if (!ret && !nowait) { saved_cpu_wait = cpu_wait; cpu_wait = loongson2_cpu_wait; } return ret; } static void __exit cpufreq_exit(void) { if (!nowait && saved_cpu_wait) cpu_wait = saved_cpu_wait; cpufreq_unregister_driver(&loongson2_cpufreq_driver); cpufreq_unregister_notifier(&loongson2_cpufreq_notifier_block, CPUFREQ_TRANSITION_NOTIFIER); platform_driver_unregister(&platform_driver); } module_init(cpufreq_init); module_exit(cpufreq_exit); module_param(nowait, uint, 0644); MODULE_PARM_DESC(nowait, "Disable Loongson-2F specific wait"); MODULE_AUTHOR("Yanhua <yanh@lemote.com>"); MODULE_DESCRIPTION("cpufreq driver for Loongson2F"); MODULE_LICENSE("GPL"); |