diff options
Diffstat (limited to 'arch/sh')
| -rw-r--r-- | arch/sh/Kconfig | 2 | ||||
| -rw-r--r-- | arch/sh/kernel/cpufreq.c | 214 |
2 files changed, 81 insertions, 135 deletions
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig index 2a9682e1306..ddfd358a67c 100644 --- a/arch/sh/Kconfig +++ b/arch/sh/Kconfig @@ -475,7 +475,7 @@ source "drivers/cpufreq/Kconfig" config SH_CPU_FREQ tristate "SuperH CPU Frequency driver" - depends on CPU_FREQ && CPU_SH4 && BROKEN + depends on CPU_FREQ select CPU_FREQ_TABLE help This adds the cpufreq driver for SuperH. At present, only diff --git a/arch/sh/kernel/cpufreq.c b/arch/sh/kernel/cpufreq.c index 47abf6e49df..675118d6aea 100644 --- a/arch/sh/kernel/cpufreq.c +++ b/arch/sh/kernel/cpufreq.c @@ -3,89 +3,51 @@ * * cpufreq driver for the SuperH processors. * - * Copyright (C) 2002, 2003, 2004, 2005 Paul Mundt + * Copyright (C) 2002 - 2007 Paul Mundt * Copyright (C) 2002 M. R. Brown * - * 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. + * Clock framework bits from arch/avr32/mach-at32ap/cpufreq.c + * + * Copyright (C) 2004-2007 Atmel Corporation + * + * 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. */ #include <linux/types.h> #include <linux/cpufreq.h> #include <linux/kernel.h> #include <linux/module.h> -#include <linux/slab.h> #include <linux/init.h> -#include <linux/delay.h> +#include <linux/err.h> #include <linux/cpumask.h> #include <linux/smp.h> #include <linux/sched.h> /* set_cpus_allowed() */ - +#include <linux/io.h> +#include <linux/clk.h> #include <asm/processor.h> #include <asm/watchdog.h> #include <asm/freq.h> -#include <asm/io.h> - -/* - * For SuperH, each policy change requires that we change the IFC, BFC, and - * PFC at the same time. Here we define sane values that won't trash the - * system. - * - * Note the max set is computed at runtime, we use the divisors that we booted - * with to setup our maximum operating frequencies. - */ -struct clock_set { - unsigned int ifc; - unsigned int bfc; - unsigned int pfc; -} clock_sets[] = { -#if defined(CONFIG_CPU_SH3) || defined(CONFIG_CPU_SH2) - { 0, 0, 0 }, /* not implemented yet */ -#elif defined(CONFIG_CPU_SH4) - { 4, 8, 8 }, /* min - IFC: 1/4, BFC: 1/8, PFC: 1/8 */ - { 1, 2, 2 }, /* max - IFC: 1, BFC: 1/2, PFC: 1/2 */ -#endif -}; - -#define MIN_CLOCK_SET 0 -#define MAX_CLOCK_SET (ARRAY_SIZE(clock_sets) - 1) - -/* - * For the time being, we only support two frequencies, which in turn are - * aimed at the POWERSAVE and PERFORMANCE policies, which in turn are derived - * directly from the respective min/max clock sets. Technically we could - * support a wider range of frequencies, but these vary far too much for each - * CPU subtype (and we'd have to construct a frequency table for each subtype). - * - * Maybe something to implement in the future.. - */ -#define SH_FREQ_MAX 0 -#define SH_FREQ_MIN 1 +#include <asm/clock.h> -static struct cpufreq_frequency_table sh_freqs[] = { - { SH_FREQ_MAX, 0 }, - { SH_FREQ_MIN, 0 }, - { 0, CPUFREQ_TABLE_END }, -}; +static struct clk *cpuclk; -static void sh_cpufreq_update_clocks(unsigned int set) +static unsigned int sh_cpufreq_get(unsigned int cpu) { - current_cpu_data.cpu_clock = current_cpu_data.master_clock / clock_sets[set].ifc; - current_cpu_data.bus_clock = current_cpu_data.master_clock / clock_sets[set].bfc; - current_cpu_data.module_clock = current_cpu_data.master_clock / clock_sets[set].pfc; - current_cpu_data.loops_per_jiffy = loops_per_jiffy; + return (clk_get_rate(cpuclk) + 500) / 1000; } -/* XXX: This needs to be split out per CPU and CPU subtype. */ /* * Here we notify other drivers of the proposed change and the final change. */ -static int sh_cpufreq_setstate(unsigned int cpu, unsigned int set) +static int sh_cpufreq_target(struct cpufreq_policy *policy, + unsigned int target_freq, + unsigned int relation) { - unsigned short frqcr = ctrl_inw(FRQCR); + unsigned int cpu = policy->cpu; cpumask_t cpus_allowed; struct cpufreq_freqs freqs; + long freq; if (!cpu_online(cpu)) return -ENODEV; @@ -95,125 +57,109 @@ static int sh_cpufreq_setstate(unsigned int cpu, unsigned int set) BUG_ON(smp_processor_id() != cpu); - freqs.cpu = cpu; - freqs.old = current_cpu_data.cpu_clock / 1000; - freqs.new = (current_cpu_data.master_clock / clock_sets[set].ifc) / 1000; + /* Convert target_freq from kHz to Hz */ + freq = clk_round_rate(cpuclk, target_freq * 1000); - cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); -#if defined(CONFIG_CPU_SH3) - frqcr |= (newstate & 0x4000) << 14; - frqcr |= (newstate & 0x000c) << 2; -#elif defined(CONFIG_CPU_SH4) - /* - * FRQCR.PLL2EN is 1, we need to allow the PLL to stabilize by - * initializing the WDT. - */ - if (frqcr & (1 << 9)) { - __u8 csr; - - /* - * Set the overflow period to the highest available, - * in this case a 1/4096 division ratio yields a 5.25ms - * overflow period. See asm-sh/watchdog.h for more - * information and a range of other divisors. - */ - csr = sh_wdt_read_csr(); - csr |= WTCSR_CKS_4096; - sh_wdt_write_csr(csr); - - sh_wdt_write_cnt(0); - } - frqcr &= 0x0e00; /* Clear ifc, bfc, pfc */ - frqcr |= get_ifc_value(clock_sets[set].ifc) << 6; - frqcr |= get_bfc_value(clock_sets[set].bfc) << 3; - frqcr |= get_pfc_value(clock_sets[set].pfc); -#endif - ctrl_outw(frqcr, FRQCR); - sh_cpufreq_update_clocks(set); + if (freq < (policy->min * 1000) || freq > (policy->max * 1000)) + return -EINVAL; + + pr_debug("cpufreq: requested frequency %u Hz\n", target_freq * 1000); + freqs.cpu = cpu; + freqs.old = sh_cpufreq_get(cpu); + freqs.new = (freq + 500) / 1000; + freqs.flags = 0; + + cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); set_cpus_allowed(current, cpus_allowed); + clk_set_rate(cpuclk, freq); cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); + pr_debug("cpufreq: set frequency %lu Hz\n", freq); + return 0; } static int sh_cpufreq_cpu_init(struct cpufreq_policy *policy) { - unsigned int min_freq, max_freq; - unsigned int ifc, bfc, pfc; + printk(KERN_INFO "cpufreq: SuperH CPU frequency driver.\n"); if (!cpu_online(policy->cpu)) return -ENODEV; - /* Update our maximum clock set */ - get_current_frequency_divisors(&ifc, &bfc, &pfc); - clock_sets[MAX_CLOCK_SET].ifc = ifc; - clock_sets[MAX_CLOCK_SET].bfc = bfc; - clock_sets[MAX_CLOCK_SET].pfc = pfc; - - /* Convert from Hz to kHz */ - max_freq = current_cpu_data.cpu_clock / 1000; - min_freq = (current_cpu_data.master_clock / clock_sets[MIN_CLOCK_SET].ifc) / 1000; - - sh_freqs[SH_FREQ_MAX].frequency = max_freq; - sh_freqs[SH_FREQ_MIN].frequency = min_freq; + cpuclk = clk_get(NULL, "cpu_clk"); + if (IS_ERR(cpuclk)) { + printk(KERN_ERR "cpufreq: couldn't get CPU clk\n"); + return PTR_ERR(cpuclk); + } /* cpuinfo and default policy values */ - policy->governor = CPUFREQ_DEFAULT_GOVERNOR; + policy->cpuinfo.min_freq = (clk_round_rate(cpuclk, 1) + 500) / 1000; + policy->cpuinfo.max_freq = (clk_round_rate(cpuclk, ~0UL) + 500) / 1000; policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; - policy->cur = max_freq; - return cpufreq_frequency_table_cpuinfo(policy, &sh_freqs[0]); -} + policy->governor = CPUFREQ_DEFAULT_GOVERNOR; + policy->cur = sh_cpufreq_get(policy->cpu); + policy->min = policy->cpuinfo.min_freq; + policy->max = policy->cpuinfo.max_freq; -static int sh_cpufreq_verify(struct cpufreq_policy *policy) -{ - return cpufreq_frequency_table_verify(policy, &sh_freqs[0]); -} -static int sh_cpufreq_target(struct cpufreq_policy *policy, - unsigned int target_freq, - unsigned int relation) -{ - unsigned int set, idx = 0; + /* + * Catch the cases where the clock framework hasn't been wired up + * properly to support scaling. + */ + if (unlikely(policy->min == policy->max)) { + printk(KERN_ERR "cpufreq: clock framework rate rounding " + "not supported on this CPU.\n"); - if (cpufreq_frequency_table_target(policy, &sh_freqs[0], target_freq, relation, &idx)) + clk_put(cpuclk); return -EINVAL; + } - set = (idx == SH_FREQ_MIN) ? MIN_CLOCK_SET : MAX_CLOCK_SET; + printk(KERN_INFO "cpufreq: Frequencies - Minimum %u.%03u MHz, " + "Maximum %u.%03u MHz.\n", + policy->min / 1000, policy->min % 1000, + policy->max / 1000, policy->max % 1000); - sh_cpufreq_setstate(policy->cpu, set); + return 0; +} +static int sh_cpufreq_verify(struct cpufreq_policy *policy) +{ + cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq, + policy->cpuinfo.max_freq); + return 0; +} + +static int sh_cpufreq_exit(struct cpufreq_policy *policy) +{ + clk_put(cpuclk); return 0; } static struct cpufreq_driver sh_cpufreq_driver = { .owner = THIS_MODULE, - .name = "SH cpufreq", + .name = "sh", .init = sh_cpufreq_cpu_init, .verify = sh_cpufreq_verify, .target = sh_cpufreq_target, + .get = sh_cpufreq_get, + .exit = sh_cpufreq_exit, }; -static int __init sh_cpufreq_init(void) +static int __init sh_cpufreq_module_init(void) { - if (!current_cpu_data.cpu_clock) - return -EINVAL; - if (cpufreq_register_driver(&sh_cpufreq_driver)) - return -EINVAL; - - return 0; + return cpufreq_register_driver(&sh_cpufreq_driver); } -static void __exit sh_cpufreq_exit(void) +static void __exit sh_cpufreq_module_exit(void) { cpufreq_unregister_driver(&sh_cpufreq_driver); } -module_init(sh_cpufreq_init); -module_exit(sh_cpufreq_exit); +module_init(sh_cpufreq_module_init); +module_exit(sh_cpufreq_module_exit); MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>"); MODULE_DESCRIPTION("cpufreq driver for SuperH"); MODULE_LICENSE("GPL"); - |