Matthew Garrett wrote:
It appears to be implemented in the 900 and 901 BIOSes as well, so some
kind of limitation is probably needed. The best approach would probably
to check whether the CPU has the EST flag. Just do something like:
struct cpuinfo_x86 *cpu = &cpu_data(policy->cpu);
if (cpu->x86_vendor != X86_VENDOR_INTEL || cpu_has(cpu, X86_FEATURE_EST))
return -ENODEV
at the top of the cpufreq init code. That way you'll refuse to bind on
anything that implements speedstep and acpi-cpufreq can be used instead.
Sounds like a good idea - here's a new version with that check added:
--- kmod-eeepc-laptop-2.6.28rc5/eeepc-laptop.c 2008-11-20 09:24:41.000000000 +0000
+++ kmod-eeepc-laptop-cpufreq/eeepc-laptop.c 2008-12-07 15:54:07.000000000 +0000
@@ -25,6 +25,7 @@
#include <linux/fb.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
+#include <linux/cpufreq.h>
#include <acpi/acpi_drivers.h>
#include <acpi/acpi_bus.h>
#include <linux/uaccess.h>
@@ -731,6 +732,118 @@
};
/*
+ * Cpufreq
+ *
+ * Based on work by Cristiano P. <cris69@xxxxxxxxx>
+ */
+static struct cpufreq_frequency_table eeepc_cpufreq_table[] = {
+ {0, 630000},
+ {1, 900000},
+ {0, CPUFREQ_TABLE_END}
+};
+
+static unsigned int eeepc_cpufreq_get(unsigned int cpu)
+{
+ switch (get_acpi(CM_ASL_CPUFV)) {
+ case 0x200:
+ return 900000;
+ case 0x201:
+ return 630000;
+ }
+
+ return 0;
+}
+
+static void eeepc_cpufreq_set(unsigned int frequency)
+{
+ struct cpufreq_freqs freqs;
+
+ freqs.cpu = 0;
+ freqs.old = eeepc_cpufreq_get(0);
+ freqs.new = frequency;
+
+ cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
+
+ switch (frequency) {
+ case 900000:
+ set_acpi(CM_ASL_CPUFV, 0);
+ break;
+ case 630000:
+ set_acpi(CM_ASL_CPUFV, 1);
+ break;
+ }
+
+ cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+
+ return;
+}
+
+static int eeepc_cpufreq_verify(struct cpufreq_policy *policy)
+{
+ return cpufreq_frequency_table_verify(policy, eeepc_cpufreq_table);
+}
+
+static int eeepc_cpufreq_target (struct cpufreq_policy *policy,
+ unsigned int target_freq,
+ unsigned int relation)
+{
+ unsigned int newstate = 0;
+
+ if (cpufreq_frequency_table_target(policy, eeepc_cpufreq_table,
+ target_freq, relation, &newstate))
+ return -EINVAL;
+
+ eeepc_cpufreq_set(eeepc_cpufreq_table[newstate].frequency);
+
+ return 0;
+}
+
+static int eeepc_cpufreq_cpu_init(struct cpufreq_policy *policy)
+{
+ struct cpuinfo_x86 *cpu = &cpu_data(policy->cpu);
+
+ /* Defer to acpi-cpufreq if this CPU has SpeedStep support */
+ if (cpu->x86_vendor != X86_VENDOR_INTEL || cpu_has(cpu, X86_FEATURE_EST))
+ return -ENODEV;
+
+ if (get_acpi(CM_ASL_CPUFV) < 0)
+ return -ENODEV;
+
+ policy->cpuinfo.transition_latency = 1000000;
+ policy->cur = eeepc_cpufreq_get(policy->cpu);
+
+ if (cpufreq_frequency_table_cpuinfo(policy, eeepc_cpufreq_table))
+ return -EINVAL;
+
+ cpufreq_frequency_table_get_attr(eeepc_cpufreq_table, policy->cpu);
+
+ return 0;
+}
+
+static int eeepc_cpufreq_cpu_exit(struct cpufreq_policy *policy)
+{
+ cpufreq_frequency_table_put_attr(policy->cpu);
+
+ return 0;
+}
+
+static struct freq_attr *eeepc_cpufreq_attr[] = {
+ &cpufreq_freq_attr_scaling_available_freqs,
+ NULL,
+};
+
+static struct cpufreq_driver eeepc_cpufreq_driver = {
+ .verify = eeepc_cpufreq_verify,
+ .target = eeepc_cpufreq_target,
+ .init = eeepc_cpufreq_cpu_init,
+ .exit = eeepc_cpufreq_cpu_exit,
+ .get = eeepc_cpufreq_get,
+ .name = "eeepc",
+ .owner = THIS_MODULE,
+ .attr = eeepc_cpufreq_attr,
+};
+
+/*
* exit/init
*/
static void eeepc_backlight_exit(void)
@@ -759,10 +872,16 @@
eeepc_hwmon_device = NULL;
}
+static void eeepc_cpufreq_exit(void)
+{
+ cpufreq_unregister_driver(&eeepc_cpufreq_driver);
+}
+
static void __exit eeepc_laptop_exit(void)
{
eeepc_backlight_exit();
eeepc_hwmon_exit();
+ eeepc_cpufreq_exit();
acpi_bus_unregister_driver(&eeepc_hotk_driver);
sysfs_remove_group(&platform_device->dev.kobj,
&platform_attribute_group);
@@ -810,6 +929,11 @@
return result;
}
+static int eeepc_cpufreq_init(struct device *dev)
+{
+ return cpufreq_register_driver(&eeepc_cpufreq_driver);
+}
+
static int __init eeepc_laptop_init(void)
{
struct device *dev;
@@ -837,6 +961,9 @@
result = eeepc_hwmon_init(dev);
if (result)
goto fail_hwmon;
+ result = eeepc_cpufreq_init(dev);
+ if (result)
+ goto fail_cpufreq;
/* Register platform stuff */
result = platform_driver_register(&platform_driver);
if (result)
@@ -861,6 +988,8 @@
fail_platform_device1:
platform_driver_unregister(&platform_driver);
fail_platform_driver:
+ eeepc_cpufreq_exit();
+fail_cpufreq:
eeepc_hwmon_exit();
fail_hwmon:
eeepc_backlight_exit();
Tom
--
Tom Hughes (tom@xxxxxxxxxx)
http://www.compton.nu/
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