diff options
Diffstat (limited to 'sys/contrib/dev/acpica/hwtimer.c')
| -rw-r--r-- | sys/contrib/dev/acpica/hwtimer.c | 60 |
1 files changed, 41 insertions, 19 deletions
diff --git a/sys/contrib/dev/acpica/hwtimer.c b/sys/contrib/dev/acpica/hwtimer.c index 52139ed..fbe61d4 100644 --- a/sys/contrib/dev/acpica/hwtimer.c +++ b/sys/contrib/dev/acpica/hwtimer.c @@ -2,7 +2,7 @@ /****************************************************************************** * * Name: hwtimer.c - ACPI Power Management Timer Interface - * $Revision: 5 $ + * $Revision: 9 $ * *****************************************************************************/ @@ -118,7 +118,7 @@ #include "acpi.h" #include "achware.h" -#define _COMPONENT HARDWARE +#define _COMPONENT ACPI_HARDWARE MODULE_NAME ("hwtimer") @@ -138,8 +138,19 @@ ACPI_STATUS AcpiGetTimerResolution ( UINT32 *Resolution) { + ACPI_STATUS Status; + FUNCTION_TRACE ("AcpiGetTimerResolution"); + + /* Ensure that ACPI has been initialized */ + + ACPI_IS_INITIALIZATION_COMPLETE (Status); + if (ACPI_FAILURE (Status)) + { + return_ACPI_STATUS (Status); + } + if (!Resolution) { return_ACPI_STATUS (AE_BAD_PARAMETER); @@ -174,8 +185,19 @@ ACPI_STATUS AcpiGetTimer ( UINT32 *Ticks) { + ACPI_STATUS Status; + FUNCTION_TRACE ("AcpiGetTimer"); + + /* Ensure that ACPI has been initialized */ + + ACPI_IS_INITIALIZATION_COMPLETE (Status); + if (ACPI_FAILURE (Status)) + { + return_ACPI_STATUS (Status); + } + if (!Ticks) { return_ACPI_STATUS (AE_BAD_PARAMETER); @@ -195,20 +217,20 @@ AcpiGetTimer ( * EndTicks * TimeElapsed * - * RETURN: TimeElapsed + * RETURN: TimeElapsed * * DESCRIPTION: Computes the time elapsed (in microseconds) between two * PM Timer time stamps, taking into account the possibility of - * rollovers, the timer resolution, and timer frequency. - * - * The PM Timer's clock ticks at roughly 3.6 times per + * rollovers, the timer resolution, and timer frequency. + * + * The PM Timer's clock ticks at roughly 3.6 times per * _microsecond_, and its clock continues through Cx state * transitions (unlike many CPU timestamp counters) -- making it * a versatile and accurate timer. * - * Note that this function accomodates only a single timer + * Note that this function accomodates only a single timer * rollover. Thus for 24-bit timers, this function should only - * be used for calculating durations less than ~4.6 seconds + * be used for calculating durations less than ~4.6 seconds * (~20 hours for 32-bit timers). * ******************************************************************************/ @@ -227,12 +249,12 @@ AcpiGetTimerDuration ( FUNCTION_TRACE ("AcpiGetTimerDuration"); - if (!TimeElapsed) + if (!TimeElapsed) { return_ACPI_STATUS (AE_BAD_PARAMETER); } - /* + /* * Compute Tick Delta: * ------------------- * Handle (max one) timer rollovers on 24- versus 32-bit timers. @@ -241,7 +263,7 @@ AcpiGetTimerDuration ( { DeltaTicks = EndTicks - StartTicks; } - else if (StartTicks > EndTicks) + else if (StartTicks > EndTicks) { /* 24-bit Timer */ if (0 == AcpiGbl_FADT->TmrValExt) @@ -249,7 +271,7 @@ AcpiGetTimerDuration ( DeltaTicks = (((0x00FFFFFF - StartTicks) + EndTicks) & 0x00FFFFFF); } /* 32-bit Timer */ - else + else { DeltaTicks = (0xFFFFFFFF - StartTicks) + EndTicks; } @@ -260,17 +282,17 @@ AcpiGetTimerDuration ( return_ACPI_STATUS (AE_OK); } - /* + /* * Compute Duration: * ----------------- - * Since certain compilers (gcc/Linux, argh!) don't support 64-bit - * divides in kernel-space we have to do some trickery to preserve + * Since certain compilers (gcc/Linux, argh!) don't support 64-bit + * divides in kernel-space we have to do some trickery to preserve * accuracy while using 32-bit math. * - * TODO: Change to use 64-bit math when supported. - * + * TBD: Change to use 64-bit math when supported. + * * The process is as follows: - * 1. Compute the number of seconds by dividing Delta Ticks by + * 1. Compute the number of seconds by dividing Delta Ticks by * the timer frequency. * 2. Compute the number of milliseconds in the remainder from step #1 * by multiplying by 1000 and then dividing by the timer frequency. @@ -278,7 +300,7 @@ AcpiGetTimerDuration ( * by multiplying by 1000 and then dividing by the timer frequency. * 4. Add the results from steps 1, 2, and 3 to get the total duration. * - * Example: The time elapsed for DeltaTicks = 0xFFFFFFFF should be + * Example: The time elapsed for DeltaTicks = 0xFFFFFFFF should be * 1199864031 microseconds. This is computed as follows: * Step #1: Seconds = 1199; Remainder = 3092840 * Step #2: Milliseconds = 864; Remainder = 113120 |
