linux 2.6.16.38 w/ vs2.0.3-rc1

[linux-2.6.git] / arch / i386 / kernel / timers / timer_pm.c

diff --git a/arch/i386/kernel/timers/timer_pm.c b/arch/i386/kernel/timers/timer_pm.c
index 7aa63c9..264edaa 100644 (file)
--- a/arch/i386/kernel/timers/timer_pm.c
+++ b/arch/i386/kernel/timers/timer_pm.c
@@ -21,6 +21,14 @@
 #include <asm/io.h>
 #include <asm/arch_hooks.h>
 
+#include <linux/timex.h>
+#include "mach_timer.h"
+
+/* Number of PMTMR ticks expected during calibration run */
+#define PMTMR_TICKS_PER_SEC 3579545
+#define PMTMR_EXPECTED_RATE \
+  ((CALIBRATE_LATCH * (PMTMR_TICKS_PER_SEC >> 10)) / (CLOCK_TICK_RATE>>10))
+
 
 /* The I/O port the PMTMR resides at.
  * The location is detected during setup_arch(),
@@ -57,6 +65,33 @@ static inline u32 read_pmtmr(void)
        return v2 & ACPI_PM_MASK;
 }
 
+
+/*
+ * Some boards have the PMTMR running way too fast. We check
+ * the PMTMR rate against PIT channel 2 to catch these cases.
+ */
+static int verify_pmtmr_rate(void)
+{
+       u32 value1, value2;
+       unsigned long count, delta;
+
+       mach_prepare_counter();
+       value1 = read_pmtmr();
+       mach_countup(&count);
+       value2 = read_pmtmr();
+       delta = (value2 - value1) & ACPI_PM_MASK;
+
+       /* Check that the PMTMR delta is within 5% of what we expect */
+       if (delta < (PMTMR_EXPECTED_RATE * 19) / 20 ||
+           delta > (PMTMR_EXPECTED_RATE * 21) / 20) {
+               printk(KERN_INFO "PM-Timer running at invalid rate: %lu%% of normal - aborting.\n", 100UL * delta / PMTMR_EXPECTED_RATE);
+               return -1;
+       }
+
+       return 0;
+}
+
+
 static int init_pmtmr(char* override)
 {
        u32 value1, value2;
@@ -89,6 +124,9 @@ static int init_pmtmr(char* override)
        return -ENODEV;
 
 pm_good:
+       if (verify_pmtmr_rate() != 0)
+               return -ENODEV;
+
        init_cpu_khz();
        return 0;
 }
@@ -148,6 +186,14 @@ static void mark_offset_pmtmr(void)
        }
 }
 
+static int pmtmr_resume(void)
+{
+       write_seqlock(&monotonic_lock);
+       /* Assume this is the last mark offset time */
+       offset_tick = read_pmtmr();
+       write_sequnlock(&monotonic_lock);
+       return 0;
+}
 
 static unsigned long long monotonic_clock_pmtmr(void)
 {
@@ -202,15 +248,20 @@ static unsigned long get_offset_pmtmr(void)
 
 
 /* acpi timer_opts struct */
-struct timer_opts timer_pmtmr = {
+static struct timer_opts timer_pmtmr = {
        .name                   = "pmtmr",
-       .init                   = init_pmtmr,
        .mark_offset            = mark_offset_pmtmr,
        .get_offset             = get_offset_pmtmr,
        .monotonic_clock        = monotonic_clock_pmtmr,
        .delay                  = delay_pmtmr,
+       .read_timer             = read_timer_tsc,
+       .resume                 = pmtmr_resume,
 };
 
+struct init_timer_opts __initdata timer_pmtmr_init = {
+       .init = init_pmtmr,
+       .opts = &timer_pmtmr,
+};
 
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Dominik Brodowski <linux@brodo.de>");