On Fri, Sep 12, 2014 at 10:00:13PM +0800, Hanjun Guo wrote:
Using the information presented by GTDT to initialize the arch timer (not memory-mapped).
Originally-by: Amit Daniel Kachhap amit.daniel@samsung.com Signed-off-by: Hanjun Guo hanjun.guo@linaro.org
arch/arm64/kernel/time.c | 7 ++ drivers/clocksource/arm_arch_timer.c | 117 ++++++++++++++++++++++++++++------ include/linux/clocksource.h | 6 ++ 3 files changed, 111 insertions(+), 19 deletions(-)
diff --git a/arch/arm64/kernel/time.c b/arch/arm64/kernel/time.c index 1a7125c..42f9195 100644 --- a/arch/arm64/kernel/time.c +++ b/arch/arm64/kernel/time.c @@ -35,6 +35,7 @@ #include <linux/delay.h> #include <linux/clocksource.h> #include <linux/clk-provider.h> +#include <linux/acpi.h> #include <clocksource/arm_arch_timer.h> @@ -72,6 +73,12 @@ void __init time_init(void) tick_setup_hrtimer_broadcast();
- /*
* Since ACPI or FDT will only one be available in the system,
* we can use acpi_generic_timer_init() here safely
*/
- acpi_generic_timer_init();
- arch_timer_rate = arch_timer_get_rate(); if (!arch_timer_rate) panic("Unable to initialise architected timer.\n");
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index 5163ec1..397783f 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -21,6 +21,7 @@ #include <linux/io.h> #include <linux/slab.h> #include <linux/sched_clock.h> +#include <linux/acpi.h> #include <asm/arch_timer.h> #include <asm/virt.h> @@ -338,8 +339,12 @@ arch_timer_detect_rate(void __iomem *cntbase, struct device_node *np) if (arch_timer_rate) return;
- /* Try to determine the frequency from the device tree or CNTFRQ */
- if (of_property_read_u32(np, "clock-frequency", &arch_timer_rate)) {
- /*
* Try to determine the frequency from the device tree or CNTFRQ,
* if ACPI is enabled, get the frequency from CNTFRQ ONLY.
*/
If ACPI is enabled, the tree won't have been unflattened and there wouldn't be a property to match. So I don't think the extra check is needed here.
If anything, add a check to make sure "np" is non-null instead.
- if (!acpi_disabled ||
if (cntbase) arch_timer_rate = readl_relaxed(cntbase + CNTFRQ); elseof_property_read_u32(np, "clock-frequency", &arch_timer_rate)) {
-Olof