1 files changed, 256 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k6.c b/arch/x86/kernel/cpu/cpufreq/powernow-k6.c
new file mode 100644
index 0000000..f895240
--- /dev/null
+++ b/arch/x86/kernel/cpu/cpufreq/powernow-k6.c
@@ -0,0 +1,256 @@
+/*
+ *  This file was based upon code in Powertweak Linux (http://powertweak.sf.net)
+ *  (C) 2000-2003  Dave Jones, Arjan van de Ven, Janne Pänkälä, Dominik Brodowski.
+ *
+ *  Licensed under the terms of the GNU GPL License version 2.
+ *
+ *  BIG FAT DISCLAIMER: Work in progress code. Possibly *dangerous*
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/cpufreq.h>
+#include <linux/ioport.h>
+#include <linux/slab.h>
+
+#include <asm/msr.h>
+#include <asm/timex.h>
+#include <asm/io.h>
+
+
+#define POWERNOW_IOPORT 0xfff0         /* it doesn't matter where, as long
+					  as it is unused */
+
+static unsigned int                     busfreq;   /* FSB, in 10 kHz */
+static unsigned int                     max_multiplier;
+
+
+/* Clock ratio multiplied by 10 - see table 27 in AMD#23446 */
+static struct cpufreq_frequency_table clock_ratio[] = {
+	{45,  /* 000 -> 4.5x */ 0},
+	{50,  /* 001 -> 5.0x */ 0},
+	{40,  /* 010 -> 4.0x */ 0},
+	{55,  /* 011 -> 5.5x */ 0},
+	{20,  /* 100 -> 2.0x */ 0},
+	{30,  /* 101 -> 3.0x */ 0},
+	{60,  /* 110 -> 6.0x */ 0},
+	{35,  /* 111 -> 3.5x */ 0},
+	{0, CPUFREQ_TABLE_END}
+};
+
+
+/**
+ * powernow_k6_get_cpu_multiplier - returns the current FSB multiplier
+ *
+ *   Returns the current setting of the frequency multiplier. Core clock
+ * speed is frequency of the Front-Side Bus multiplied with this value.
+ */
+static int powernow_k6_get_cpu_multiplier(void)
+{
+	u64             invalue = 0;
+	u32             msrval;
+
+	msrval = POWERNOW_IOPORT + 0x1;
+	wrmsr(MSR_K6_EPMR, msrval, 0); /* enable the PowerNow port */
+	invalue=inl(POWERNOW_IOPORT + 0x8);
+	msrval = POWERNOW_IOPORT + 0x0;
+	wrmsr(MSR_K6_EPMR, msrval, 0); /* disable it again */
+
+	return clock_ratio[(invalue >> 5)&7].index;
+}
+
+
+/**
+ * powernow_k6_set_state - set the PowerNow! multiplier
+ * @best_i: clock_ratio[best_i] is the target multiplier
+ *
+ *   Tries to change the PowerNow! multiplier
+ */
+static void powernow_k6_set_state (unsigned int best_i)
+{
+	unsigned long           outvalue=0, invalue=0;
+	unsigned long           msrval;
+	struct cpufreq_freqs    freqs;
+
+	if (clock_ratio[best_i].index > max_multiplier) {
+		printk(KERN_ERR "cpufreq: invalid target frequency\n");
+		return;
+	}
+
+	freqs.old = busfreq * powernow_k6_get_cpu_multiplier();
+	freqs.new = busfreq * clock_ratio[best_i].index;
+	freqs.cpu = 0; /* powernow-k6.c is UP only driver */
+
+	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
+
+	/* we now need to transform best_i to the BVC format, see AMD#23446 */
+
+	outvalue = (1<<12) | (1<<10) | (1<<9) | (best_i<<5);
+
+	msrval = POWERNOW_IOPORT + 0x1;
+	wrmsr(MSR_K6_EPMR, msrval, 0); /* enable the PowerNow port */
+	invalue=inl(POWERNOW_IOPORT + 0x8);
+	invalue = invalue & 0xf;
+	outvalue = outvalue | invalue;
+	outl(outvalue ,(POWERNOW_IOPORT + 0x8));
+	msrval = POWERNOW_IOPORT + 0x0;
+	wrmsr(MSR_K6_EPMR, msrval, 0); /* disable it again */
+
+	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+
+	return;
+}
+
+
+/**
+ * powernow_k6_verify - verifies a new CPUfreq policy
+ * @policy: new policy
+ *
+ * Policy must be within lowest and highest possible CPU Frequency,
+ * and at least one possible state must be within min and max.
+ */
+static int powernow_k6_verify(struct cpufreq_policy *policy)
+{
+	return cpufreq_frequency_table_verify(policy, &clock_ratio[0]);
+}
+
+
+/**
+ * powernow_k6_setpolicy - sets a new CPUFreq policy
+ * @policy: new policy
+ * @target_freq: the target frequency
+ * @relation: how that frequency relates to achieved frequency (CPUFREQ_RELATION_L or CPUFREQ_RELATION_H)
+ *
+ * sets a new CPUFreq policy
+ */
+static int powernow_k6_target (struct cpufreq_policy *policy,
+			       unsigned int target_freq,
+			       unsigned int relation)
+{
+	unsigned int    newstate = 0;
+
+	if (cpufreq_frequency_table_target(policy, &clock_ratio[0], target_freq, relation, &newstate))
+		return -EINVAL;
+
+	powernow_k6_set_state(newstate);
+
+	return 0;
+}
+
+
+static int powernow_k6_cpu_init(struct cpufreq_policy *policy)
+{
+	unsigned int i;
+	int result;
+
+	if (policy->cpu != 0)
+		return -ENODEV;
+
+	/* get frequencies */
+	max_multiplier = powernow_k6_get_cpu_multiplier();
+	busfreq = cpu_khz / max_multiplier;
+
+	/* table init */
+	for (i=0; (clock_ratio[i].frequency != CPUFREQ_TABLE_END); i++) {
+		if (clock_ratio[i].index > max_multiplier)
+			clock_ratio[i].frequency = CPUFREQ_ENTRY_INVALID;
+		else
+			clock_ratio[i].frequency = busfreq * clock_ratio[i].index;
+	}
+
+	/* cpuinfo and default policy values */
+	policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
+	policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
+	policy->cur = busfreq * max_multiplier;
+
+	result = cpufreq_frequency_table_cpuinfo(policy, clock_ratio);
+	if (result)
+		return (result);
+
+	cpufreq_frequency_table_get_attr(clock_ratio, policy->cpu);
+
+	return 0;
+}
+
+
+static int powernow_k6_cpu_exit(struct cpufreq_policy *policy)
+{
+	unsigned int i;
+	for (i=0; i<8; i++) {
+		if (i==max_multiplier)
+			powernow_k6_set_state(i);
+	}
+	cpufreq_frequency_table_put_attr(policy->cpu);
+	return 0;
+}
+
+static unsigned int powernow_k6_get(unsigned int cpu)
+{
+	return busfreq * powernow_k6_get_cpu_multiplier();
+}
+
+static struct freq_attr* powernow_k6_attr[] = {
+	&cpufreq_freq_attr_scaling_available_freqs,
+	NULL,
+};
+
+static struct cpufreq_driver powernow_k6_driver = {
+	.verify		= powernow_k6_verify,
+	.target		= powernow_k6_target,
+	.init		= powernow_k6_cpu_init,
+	.exit		= powernow_k6_cpu_exit,
+	.get		= powernow_k6_get,
+	.name		= "powernow-k6",
+	.owner		= THIS_MODULE,
+	.attr		= powernow_k6_attr,
+};
+
+
+/**
+ * powernow_k6_init - initializes the k6 PowerNow! CPUFreq driver
+ *
+ *   Initializes the K6 PowerNow! support. Returns -ENODEV on unsupported
+ * devices, -EINVAL or -ENOMEM on problems during initiatization, and zero
+ * on success.
+ */
+static int __init powernow_k6_init(void)
+{
+	struct cpuinfo_x86      *c = cpu_data;
+
+	if ((c->x86_vendor != X86_VENDOR_AMD) || (c->x86 != 5) ||
+		((c->x86_model != 12) && (c->x86_model != 13)))
+		return -ENODEV;
+
+	if (!request_region(POWERNOW_IOPORT, 16, "PowerNow!")) {
+		printk("cpufreq: PowerNow IOPORT region already used.\n");
+		return -EIO;
+	}
+
+	if (cpufreq_register_driver(&powernow_k6_driver)) {
+		release_region (POWERNOW_IOPORT, 16);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+
+/**
+ * powernow_k6_exit - unregisters AMD K6-2+/3+ PowerNow! support
+ *
+ *   Unregisters AMD K6-2+ / K6-3+ PowerNow! support.
+ */
+static void __exit powernow_k6_exit(void)
+{
+	cpufreq_unregister_driver(&powernow_k6_driver);
+	release_region (POWERNOW_IOPORT, 16);
+}
+
+
+MODULE_AUTHOR ("Arjan van de Ven <arjanv@redhat.com>, Dave Jones <davej@codemonkey.org.uk>, Dominik Brodowski <linux@brodo.de>");
+MODULE_DESCRIPTION ("PowerNow! driver for AMD K6-2+ / K6-3+ processors.");
+MODULE_LICENSE ("GPL");
+
+module_init(powernow_k6_init);
+module_exit(powernow_k6_exit);