clocksource: add common i8253 PIT clocksource
[linux-2.6.git] / drivers / clocksource / acpi_pm.c
index 3df3384..effe797 100644 (file)
 
 #include <linux/acpi_pmtmr.h>
 #include <linux/clocksource.h>
+#include <linux/timex.h>
 #include <linux/errno.h>
 #include <linux/init.h>
 #include <linux/pci.h>
+#include <linux/delay.h>
 #include <asm/io.h>
 
 /*
@@ -56,12 +58,7 @@ u32 acpi_pm_read_verified(void)
        return v2;
 }
 
-static cycle_t acpi_pm_read_slow(void)
-{
-       return (cycle_t)acpi_pm_read_verified();
-}
-
-static cycle_t acpi_pm_read(void)
+static cycle_t acpi_pm_read(struct clocksource *cs)
 {
        return (cycle_t)read_pmtmr();
 }
@@ -71,10 +68,7 @@ static struct clocksource clocksource_acpi_pm = {
        .rating         = 200,
        .read           = acpi_pm_read,
        .mask           = (cycle_t)ACPI_PM_MASK,
-       .mult           = 0, /*to be calculated*/
-       .shift          = 22,
        .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
-
 };
 
 
@@ -87,6 +81,11 @@ static int __init acpi_pm_good_setup(char *__str)
 }
 __setup("acpi_pm_good", acpi_pm_good_setup);
 
+static cycle_t acpi_pm_read_slow(struct clocksource *cs)
+{
+       return (cycle_t)acpi_pm_read_verified();
+}
+
 static inline void acpi_pm_need_workaround(void)
 {
        clocksource_acpi_pm.read = acpi_pm_read_slow;
@@ -142,7 +141,7 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SERVERWORKS, PCI_DEVICE_ID_SERVERWORKS_LE,
 #endif
 
 #ifndef CONFIG_X86_64
-#include "mach_timer.h"
+#include <asm/mach_timer.h>
 #define PMTMR_EXPECTED_RATE \
   ((CALIBRATE_LATCH * (PMTMR_TICKS_PER_SEC >> 10)) / (CLOCK_TICK_RATE>>10))
 /*
@@ -151,13 +150,13 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SERVERWORKS, PCI_DEVICE_ID_SERVERWORKS_LE,
  */
 static int verify_pmtmr_rate(void)
 {
-       u32 value1, value2;
+       cycle_t value1, value2;
        unsigned long count, delta;
 
        mach_prepare_counter();
-       value1 = read_pmtmr();
+       value1 = clocksource_acpi_pm.read(&clocksource_acpi_pm);
        mach_countup(&count);
-       value2 = read_pmtmr();
+       value2 = clocksource_acpi_pm.read(&clocksource_acpi_pm);
        delta = (value2 - value1) & ACPI_PM_MASK;
 
        /* Check that the PMTMR delta is within 5% of what we expect */
@@ -175,40 +174,52 @@ static int verify_pmtmr_rate(void)
 #define verify_pmtmr_rate() (0)
 #endif
 
+/* Number of monotonicity checks to perform during initialization */
+#define ACPI_PM_MONOTONICITY_CHECKS 10
+/* Number of reads we try to get two different values */
+#define ACPI_PM_READ_CHECKS 10000
+
 static int __init init_acpi_pm_clocksource(void)
 {
-       u32 value1, value2;
-       unsigned int i;
+       cycle_t value1, value2;
+       unsigned int i, j = 0;
 
        if (!pmtmr_ioport)
                return -ENODEV;
 
-       clocksource_acpi_pm.mult = clocksource_hz2mult(PMTMR_TICKS_PER_SEC,
-                                               clocksource_acpi_pm.shift);
-
        /* "verify" this timing source: */
-       value1 = read_pmtmr();
-       for (i = 0; i < 10000; i++) {
-               value2 = read_pmtmr();
-               if (value2 == value1)
-                       continue;
-               if (value2 > value1)
-                       goto pm_good;
-               if ((value2 < value1) && ((value2) < 0xFFF))
-                       goto pm_good;
-               printk(KERN_INFO "PM-Timer had inconsistent results:"
-                       " 0x%#x, 0x%#x - aborting.\n", value1, value2);
-               return -EINVAL;
+       for (j = 0; j < ACPI_PM_MONOTONICITY_CHECKS; j++) {
+               udelay(100 * j);
+               value1 = clocksource_acpi_pm.read(&clocksource_acpi_pm);
+               for (i = 0; i < ACPI_PM_READ_CHECKS; i++) {
+                       value2 = clocksource_acpi_pm.read(&clocksource_acpi_pm);
+                       if (value2 == value1)
+                               continue;
+                       if (value2 > value1)
+                               break;
+                       if ((value2 < value1) && ((value2) < 0xFFF))
+                               break;
+                       printk(KERN_INFO "PM-Timer had inconsistent results:"
+                              " 0x%#llx, 0x%#llx - aborting.\n",
+                              value1, value2);
+                       pmtmr_ioport = 0;
+                       return -EINVAL;
+               }
+               if (i == ACPI_PM_READ_CHECKS) {
+                       printk(KERN_INFO "PM-Timer failed consistency check "
+                              " (0x%#llx) - aborting.\n", value1);
+                       pmtmr_ioport = 0;
+                       return -ENODEV;
+               }
        }
-       printk(KERN_INFO "PM-Timer had no reasonable result:"
-                       " 0x%#x - aborting.\n", value1);
-       return -ENODEV;
 
-pm_good:
-       if (verify_pmtmr_rate() != 0)
+       if (verify_pmtmr_rate() != 0){
+               pmtmr_ioport = 0;
                return -ENODEV;
+       }
 
-       return clocksource_register(&clocksource_acpi_pm);
+       return clocksource_register_hz(&clocksource_acpi_pm,
+                                               PMTMR_TICKS_PER_SEC);
 }
 
 /* We use fs_initcall because we want the PCI fixups to have run