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path: root/drivers/cpufreq/integrator-cpufreq.c
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Diffstat (limited to 'drivers/cpufreq/integrator-cpufreq.c')
-rw-r--r--drivers/cpufreq/integrator-cpufreq.c220
1 files changed, 220 insertions, 0 deletions
diff --git a/drivers/cpufreq/integrator-cpufreq.c b/drivers/cpufreq/integrator-cpufreq.c
new file mode 100644
index 0000000..f7c99df
--- /dev/null
+++ b/drivers/cpufreq/integrator-cpufreq.c
@@ -0,0 +1,220 @@
+/*
+ * Copyright (C) 2001-2002 Deep Blue Solutions Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * CPU support functions
+ */
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/cpufreq.h>
+#include <linux/sched.h>
+#include <linux/smp.h>
+#include <linux/init.h>
+#include <linux/io.h>
+
+#include <mach/hardware.h>
+#include <mach/platform.h>
+#include <asm/mach-types.h>
+#include <asm/hardware/icst.h>
+
+static struct cpufreq_driver integrator_driver;
+
+#define CM_ID __io_address(INTEGRATOR_HDR_ID)
+#define CM_OSC __io_address(INTEGRATOR_HDR_OSC)
+#define CM_STAT __io_address(INTEGRATOR_HDR_STAT)
+#define CM_LOCK __io_address(INTEGRATOR_HDR_LOCK)
+
+static const struct icst_params lclk_params = {
+ .ref = 24000000,
+ .vco_max = ICST525_VCO_MAX_5V,
+ .vco_min = ICST525_VCO_MIN,
+ .vd_min = 8,
+ .vd_max = 132,
+ .rd_min = 24,
+ .rd_max = 24,
+ .s2div = icst525_s2div,
+ .idx2s = icst525_idx2s,
+};
+
+static const struct icst_params cclk_params = {
+ .ref = 24000000,
+ .vco_max = ICST525_VCO_MAX_5V,
+ .vco_min = ICST525_VCO_MIN,
+ .vd_min = 12,
+ .vd_max = 160,
+ .rd_min = 24,
+ .rd_max = 24,
+ .s2div = icst525_s2div,
+ .idx2s = icst525_idx2s,
+};
+
+/*
+ * Validate the speed policy.
+ */
+static int integrator_verify_policy(struct cpufreq_policy *policy)
+{
+ struct icst_vco vco;
+
+ cpufreq_verify_within_limits(policy,
+ policy->cpuinfo.min_freq,
+ policy->cpuinfo.max_freq);
+
+ vco = icst_hz_to_vco(&cclk_params, policy->max * 1000);
+ policy->max = icst_hz(&cclk_params, vco) / 1000;
+
+ vco = icst_hz_to_vco(&cclk_params, policy->min * 1000);
+ policy->min = icst_hz(&cclk_params, vco) / 1000;
+
+ cpufreq_verify_within_limits(policy,
+ policy->cpuinfo.min_freq,
+ policy->cpuinfo.max_freq);
+
+ return 0;
+}
+
+
+static int integrator_set_target(struct cpufreq_policy *policy,
+ unsigned int target_freq,
+ unsigned int relation)
+{
+ cpumask_t cpus_allowed;
+ int cpu = policy->cpu;
+ struct icst_vco vco;
+ struct cpufreq_freqs freqs;
+ u_int cm_osc;
+
+ /*
+ * Save this threads cpus_allowed mask.
+ */
+ cpus_allowed = current->cpus_allowed;
+
+ /*
+ * Bind to the specified CPU. When this call returns,
+ * we should be running on the right CPU.
+ */
+ set_cpus_allowed(current, cpumask_of_cpu(cpu));
+ BUG_ON(cpu != smp_processor_id());
+
+ /* get current setting */
+ cm_osc = __raw_readl(CM_OSC);
+
+ if (machine_is_integrator()) {
+ vco.s = (cm_osc >> 8) & 7;
+ } else if (machine_is_cintegrator()) {
+ vco.s = 1;
+ }
+ vco.v = cm_osc & 255;
+ vco.r = 22;
+ freqs.old = icst_hz(&cclk_params, vco) / 1000;
+
+ /* icst_hz_to_vco rounds down -- so we need the next
+ * larger freq in case of CPUFREQ_RELATION_L.
+ */
+ if (relation == CPUFREQ_RELATION_L)
+ target_freq += 999;
+ if (target_freq > policy->max)
+ target_freq = policy->max;
+ vco = icst_hz_to_vco(&cclk_params, target_freq * 1000);
+ freqs.new = icst_hz(&cclk_params, vco) / 1000;
+
+ if (freqs.old == freqs.new) {
+ set_cpus_allowed(current, cpus_allowed);
+ return 0;
+ }
+
+ cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
+
+ cm_osc = __raw_readl(CM_OSC);
+
+ if (machine_is_integrator()) {
+ cm_osc &= 0xfffff800;
+ cm_osc |= vco.s << 8;
+ } else if (machine_is_cintegrator()) {
+ cm_osc &= 0xffffff00;
+ }
+ cm_osc |= vco.v;
+
+ __raw_writel(0xa05f, CM_LOCK);
+ __raw_writel(cm_osc, CM_OSC);
+ __raw_writel(0, CM_LOCK);
+
+ /*
+ * Restore the CPUs allowed mask.
+ */
+ set_cpus_allowed(current, cpus_allowed);
+
+ cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
+
+ return 0;
+}
+
+static unsigned int integrator_get(unsigned int cpu)
+{
+ cpumask_t cpus_allowed;
+ unsigned int current_freq;
+ u_int cm_osc;
+ struct icst_vco vco;
+
+ cpus_allowed = current->cpus_allowed;
+
+ set_cpus_allowed(current, cpumask_of_cpu(cpu));
+ BUG_ON(cpu != smp_processor_id());
+
+ /* detect memory etc. */
+ cm_osc = __raw_readl(CM_OSC);
+
+ if (machine_is_integrator()) {
+ vco.s = (cm_osc >> 8) & 7;
+ } else {
+ vco.s = 1;
+ }
+ vco.v = cm_osc & 255;
+ vco.r = 22;
+
+ current_freq = icst_hz(&cclk_params, vco) / 1000; /* current freq */
+
+ set_cpus_allowed(current, cpus_allowed);
+
+ return current_freq;
+}
+
+static int integrator_cpufreq_init(struct cpufreq_policy *policy)
+{
+
+ /* set default policy and cpuinfo */
+ policy->cpuinfo.max_freq = 160000;
+ policy->cpuinfo.min_freq = 12000;
+ policy->cpuinfo.transition_latency = 1000000; /* 1 ms, assumed */
+ policy->cur = policy->min = policy->max = integrator_get(policy->cpu);
+
+ return 0;
+}
+
+static struct cpufreq_driver integrator_driver = {
+ .verify = integrator_verify_policy,
+ .target = integrator_set_target,
+ .get = integrator_get,
+ .init = integrator_cpufreq_init,
+ .name = "integrator",
+};
+
+static int __init integrator_cpu_init(void)
+{
+ return cpufreq_register_driver(&integrator_driver);
+}
+
+static void __exit integrator_cpu_exit(void)
+{
+ cpufreq_unregister_driver(&integrator_driver);
+}
+
+MODULE_AUTHOR ("Russell M. King");
+MODULE_DESCRIPTION ("cpufreq driver for ARM Integrator CPUs");
+MODULE_LICENSE ("GPL");
+
+module_init(integrator_cpu_init);
+module_exit(integrator_cpu_exit);