1 files changed, 78 insertions, 137 deletions

diff --git a/arch/sh/kernel/cpufreq.c b/arch/sh/kernel/cpufreq.c
index 47abf6e49dfb..e61890217c50 100644
--- a/arch/sh/kernel/cpufreq.c
+++ b/arch/sh/kernel/cpufreq.c
@@ -3,89 +3,46 @@
  *
  * 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/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
-
-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 +52,109 @@ 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");
-