[CPUFREQ] AMD Elan SC520 cpufreq driver.
From: Sean Young <sean@mess.org>
Signed-off-by: Dave Jones <davej@redhat.com>
diff --git a/arch/i386/kernel/cpu/cpufreq/Kconfig b/arch/i386/kernel/cpu/cpufreq/Kconfig
index f25ffd7..0f1eb50 100644
--- a/arch/i386/kernel/cpu/cpufreq/Kconfig
+++ b/arch/i386/kernel/cpu/cpufreq/Kconfig
@@ -23,7 +23,7 @@
If in doubt, say N.
config ELAN_CPUFREQ
- tristate "AMD Elan"
+ tristate "AMD Elan SC400 and SC410"
select CPU_FREQ_TABLE
depends on X86_ELAN
---help---
@@ -38,6 +38,18 @@
If in doubt, say N.
+config SC520_CPUFREQ
+ tristate "AMD Elan SC520"
+ select CPU_FREQ_TABLE
+ depends on X86_ELAN
+ ---help---
+ This adds the CPUFreq driver for AMD Elan SC520 processor.
+
+ For details, take a look at <file:Documentation/cpu-freq/>.
+
+ If in doubt, say N.
+
+
config X86_POWERNOW_K6
tristate "AMD Mobile K6-2/K6-3 PowerNow!"
select CPU_FREQ_TABLE
diff --git a/arch/i386/kernel/cpu/cpufreq/Makefile b/arch/i386/kernel/cpu/cpufreq/Makefile
index a922e97..2e894f1 100644
--- a/arch/i386/kernel/cpu/cpufreq/Makefile
+++ b/arch/i386/kernel/cpu/cpufreq/Makefile
@@ -3,6 +3,7 @@
obj-$(CONFIG_X86_POWERNOW_K8) += powernow-k8.o
obj-$(CONFIG_X86_LONGHAUL) += longhaul.o
obj-$(CONFIG_ELAN_CPUFREQ) += elanfreq.o
+obj-$(CONFIG_SC520_CPUFREQ) += sc520_freq.o
obj-$(CONFIG_X86_LONGRUN) += longrun.o
obj-$(CONFIG_X86_GX_SUSPMOD) += gx-suspmod.o
obj-$(CONFIG_X86_SPEEDSTEP_ICH) += speedstep-ich.o
diff --git a/arch/i386/kernel/cpu/cpufreq/sc520_freq.c b/arch/i386/kernel/cpu/cpufreq/sc520_freq.c
new file mode 100644
index 0000000..ef457d5
--- /dev/null
+++ b/arch/i386/kernel/cpu/cpufreq/sc520_freq.c
@@ -0,0 +1,186 @@
+/*
+ * sc520_freq.c: cpufreq driver for the AMD Elan sc520
+ *
+ * Copyright (C) 2005 Sean Young <sean@mess.org>
+ *
+ * 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.
+ *
+ * Based on elanfreq.c
+ *
+ * 2005-03-30: - initial revision
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+
+#include <linux/delay.h>
+#include <linux/cpufreq.h>
+
+#include <asm/msr.h>
+#include <asm/timex.h>
+#include <asm/io.h>
+
+#define MMCR_BASE 0xfffef000 /* The default base address */
+#define OFFS_CPUCTL 0x2 /* CPU Control Register */
+
+static __u8 __iomem *cpuctl;
+
+#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "sc520_freq", msg)
+
+static struct cpufreq_frequency_table sc520_freq_table[] = {
+ {0x01, 100000},
+ {0x02, 133000},
+ {0, CPUFREQ_TABLE_END},
+};
+
+static unsigned int sc520_freq_get_cpu_frequency(unsigned int cpu)
+{
+ u8 clockspeed_reg = *cpuctl;
+
+ switch (clockspeed_reg & 0x03) {
+ default:
+ printk(KERN_ERR "sc520_freq: error: cpuctl register has unexpected value %02x\n", clockspeed_reg);
+ case 0x01:
+ return 100000;
+ case 0x02:
+ return 133000;
+ }
+}
+
+static void sc520_freq_set_cpu_state (unsigned int state)
+{
+
+ struct cpufreq_freqs freqs;
+ u8 clockspeed_reg;
+
+ freqs.old = sc520_freq_get_cpu_frequency(0);
+ freqs.new = sc520_freq_table[state].frequency;
+ freqs.cpu = 0; /* AMD Elan is UP */
+
+ cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
+
+ dprintk("attempting to set frequency to %i kHz\n",
+ sc520_freq_table[state].frequency);
+
+ local_irq_disable();
+
+ clockspeed_reg = *cpuctl & ~0x03;
+ *cpuctl = clockspeed_reg | sc520_freq_table[state].index;
+
+ local_irq_enable();
+
+ cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+};
+
+static int sc520_freq_verify (struct cpufreq_policy *policy)
+{
+ return cpufreq_frequency_table_verify(policy, &sc520_freq_table[0]);
+}
+
+static int sc520_freq_target (struct cpufreq_policy *policy,
+ unsigned int target_freq,
+ unsigned int relation)
+{
+ unsigned int newstate = 0;
+
+ if (cpufreq_frequency_table_target(policy, sc520_freq_table, target_freq, relation, &newstate))
+ return -EINVAL;
+
+ sc520_freq_set_cpu_state(newstate);
+
+ return 0;
+}
+
+
+/*
+ * Module init and exit code
+ */
+
+static int sc520_freq_cpu_init(struct cpufreq_policy *policy)
+{
+ struct cpuinfo_x86 *c = cpu_data;
+ int result;
+
+ /* capability check */
+ if (c->x86_vendor != X86_VENDOR_AMD ||
+ c->x86 != 4 || c->x86_model != 9)
+ return -ENODEV;
+
+ /* cpuinfo and default policy values */
+ policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
+ policy->cpuinfo.transition_latency = 1000000; /* 1ms */
+ policy->cur = sc520_freq_get_cpu_frequency(0);
+
+ result = cpufreq_frequency_table_cpuinfo(policy, sc520_freq_table);
+ if (result)
+ return (result);
+
+ cpufreq_frequency_table_get_attr(sc520_freq_table, policy->cpu);
+
+ return 0;
+}
+
+
+static int sc520_freq_cpu_exit(struct cpufreq_policy *policy)
+{
+ cpufreq_frequency_table_put_attr(policy->cpu);
+ return 0;
+}
+
+
+static struct freq_attr* sc520_freq_attr[] = {
+ &cpufreq_freq_attr_scaling_available_freqs,
+ NULL,
+};
+
+
+static struct cpufreq_driver sc520_freq_driver = {
+ .get = sc520_freq_get_cpu_frequency,
+ .verify = sc520_freq_verify,
+ .target = sc520_freq_target,
+ .init = sc520_freq_cpu_init,
+ .exit = sc520_freq_cpu_exit,
+ .name = "sc520_freq",
+ .owner = THIS_MODULE,
+ .attr = sc520_freq_attr,
+};
+
+
+static int __init sc520_freq_init(void)
+{
+ struct cpuinfo_x86 *c = cpu_data;
+
+ /* Test if we have the right hardware */
+ if(c->x86_vendor != X86_VENDOR_AMD ||
+ c->x86 != 4 || c->x86_model != 9) {
+ dprintk("no Elan SC520 processor found!\n");
+ return -ENODEV;
+ }
+ cpuctl = ioremap((unsigned long)(MMCR_BASE + OFFS_CPUCTL), 1);
+ if(!cpuctl) {
+ printk(KERN_ERR "sc520_freq: error: failed to remap memory\n");
+ return -ENOMEM;
+ }
+
+ return cpufreq_register_driver(&sc520_freq_driver);
+}
+
+
+static void __exit sc520_freq_exit(void)
+{
+ cpufreq_unregister_driver(&sc520_freq_driver);
+ iounmap(cpuctl);
+}
+
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Sean Young <sean@mess.org>");
+MODULE_DESCRIPTION("cpufreq driver for AMD's Elan sc520 CPU");
+
+module_init(sc520_freq_init);
+module_exit(sc520_freq_exit);
+