On Fri, Jan 17, 2014 at 12:25:11PM +0000, Hanjun Guo wrote:
> ACPI GTDT (Generic Timer Description Table) contains information for
> arch timer initialization, this patch use this table to probe arm timer.
>
> GTDT table is used for ARM/ARM64 only, please refer to chapter 5.2.24
> of ACPI 5.0 spec for detailed inforamtion
>
> Signed-off-by: Amit Daniel Kachhap <amit.daniel@xxxxxxxxxxx>
> Signed-off-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
> ---
> drivers/clocksource/arm_arch_timer.c | 100 +++++++++++++++++++++++++++++-----
> 1 file changed, 85 insertions(+), 15 deletions(-)
[...]
> +static void __init register_arch_interrupt(u32 interrupt, u32 flags,
> + int *arch_timer_ppi)
> +{
> + int trigger, polarity;
> +
> + if (!interrupt || !arch_timer_ppi)
> + return;
> +
> + trigger = (flags & ACPI_GTDT_INTERRUPT_MODE) ? ACPI_EDGE_SENSITIVE
> + : ACPI_LEVEL_SENSITIVE;
> +
> + polarity = (flags & ACPI_GTDT_INTERRUPT_POLARITY) ? ACPI_ACTIVE_LOW
> + : ACPI_ACTIVE_HIGH;
> +
> + *arch_timer_ppi = acpi_register_gsi(NULL, interrupt, trigger,
> + polarity);
> +}
Why does this take a pointer to the irq rather than returning the irq
(as with irq_of_parse_and_map)?
This looks awfully generic. Are the timer interrupts encoded specially
or is this useful for parsing other interrupts?
> +
> +static int __init acpi_parse_gtdt(struct acpi_table_header *table)
> +{
> + struct acpi_table_gtdt *gtdt;
> +
> + gtdt = (struct acpi_table_gtdt *)table;
> + if (!gtdt)
> + return -EINVAL;
> +
> + arch_timer_rate = arch_timer_get_cntfrq();
> +
> + if (!arch_timer_rate) {
> + pr_warn("arch_timer: Could not get frequency from CNTFREG\n");
s/CNTFREG/CNTFREQ/
This is probably worth a pr_err at least, the system is unlikely to get
very far if the timers don't work.
Thanks,
Mark.
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