static int __init init_acpi_pm_clocksource(void)
{
u32 value1, value2;
unsigned int i;
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;
}
printk(KERN_INFO "PM-Timer had no reasonable result:"
" 0x%#x - aborting.\n", value1);
return -ENODEV;
pm_good:
if (verify_pmtmr_rate() != 0)
return -ENODEV;
return clocksource_register(&clocksource_acpi_pm);
}
u32 acpi_pm_read_verified(void)
{
u32 v1 = 0, v2 = 0, v3 = 0;
do {
v1 = read_pmtmr();
v2 = read_pmtmr();
v3 = read_pmtmr();
} while (unlikely((v1 > v2 && v1 < v3) || (v2 > v3 && v2 < v1)
|| (v3 > v1 && v3 < v2)));
return v2;
}
static int __init cpufreq_test_tsc(void)
{
u32 now, then, diff;
u64 now_tsc, then_tsc, diff_tsc;
int i;
/*
*/
/* */
if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID) {
/* */
if (acpi_gbl_FADT.xpm_timer_block.space_id !=
ACPI_ADR_SPACE_SYSTEM_IO)
return 0;
pm_tmr_ioport = acpi_gbl_FADT.xpm_timer_block.address;
/*
*/
if (!pm_tmr_ioport)
pm_tmr_ioport = acpi_gbl_FADT.pm_timer_block;
} else {
/* */
pm_tmr_ioport = acpi_gbl_FADT.pm_timer_block;
}
printk(KERN_DEBUG "start--> \n");
then = read_pmtmr();
rdtscll(then_tsc);
for (i=0;i<20;i++) {
mdelay(100);
now = read_pmtmr();
rdtscll(now_tsc);
diff = (now - then) & 0xFFFFFF;
diff_tsc = now_tsc - then_tsc;
printk(KERN_DEBUG "t1: %08u t2: %08u diff_pmtmr: %08u diff_tsc: %016llu\n", then, now, diff, diff_tsc);
then = now;
then_tsc = now_tsc;
}
printk(KERN_DEBUG "<-- end \n");
return -ENODEV;
}
static int __init cpufreq_test_tsc(void)
{
u32 now, then, diff;
u64 now_tsc, then_tsc, diff_tsc;
int i;
/* the following code snipped is copied from arch/x86/kernel/acpi/boot.c
of Linux v2.6.25. */
/* detect the location of the ACPI PM Timer */
if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID) {
/* FADT rev. 2 */
if (acpi_gbl_FADT.xpm_timer_block.space_id !=
ACPI_ADR_SPACE_SYSTEM_IO)
return 0;
pm_tmr_ioport = acpi_gbl_FADT.xpm_timer_block.address;
/*
* "X" fields are optional extensions to the original V1.0
* fields, so we must selectively expand V1.0 fields if the
* corresponding X field is zero.
*/
if (!pm_tmr_ioport)
pm_tmr_ioport = acpi_gbl_FADT.pm_timer_block;
} else {
/* FADT rev. 1 */
pm_tmr_ioport = acpi_gbl_FADT.pm_timer_block;
}
printk(KERN_DEBUG "start--> \n");
then = read_pmtmr();
rdtscll(then_tsc);
for (i=0;i<20;i++) {
mdelay(100);
now = read_pmtmr();
rdtscll(now_tsc);
diff = (now - then) & 0xFFFFFF;
diff_tsc = now_tsc - then_tsc;
printk(KERN_DEBUG "t1: %08u t2: %08u diff_pmtmr: %08u diff_tsc: %016llu\n", then, now, diff, diff_tsc);
then = now;
then_tsc = now_tsc;
}
printk(KERN_DEBUG "<-- end \n");
return -ENODEV;
}
u32 acpi_pm_read_verified(void)
{
u32 v1 = 0, v2 = 0, v3 = 0;
/*
* It has been reported that because of various broken
* chipsets (ICH4, PIIX4 and PIIX4E) where the ACPI PM clock
* source is not latched, you must read it multiple
* times to ensure a safe value is read:
*/
do {
v1 = read_pmtmr();
v2 = read_pmtmr();
v3 = read_pmtmr();
} while (unlikely((v1 > v2 && v1 < v3) || (v2 > v3 && v2 < v1)
|| (v3 > v1 && v3 < v2)));
return v2;
}
/*
* 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 cycle_t acpi_pm_read(void)
{
return (cycle_t)read_pmtmr();
}
static cycle_t acpi_pm_read(struct clocksource *cs)
{
return (cycle_t)read_pmtmr();
}