*
* 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;
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");
-
projects / linux-2.6 / commitdiff