On 1/4/15, 04:55, "Hanjun Guo" hanjun.guo@linaro.org wrote:
Using the information presented by GTDT to initialize the arch timer (not memory-mapped).
Originally-by: Amit Daniel Kachhap amit.daniel@samsung.com Tested-by: Suravee Suthikulpanit Suravee.Suthikulpanit@amd.com Signed-off-by: Hanjun Guo hanjun.guo@linaro.org
arch/arm64/kernel/time.c | 7 ++ drivers/clocksource/arm_arch_timer.c | 132 ++++++++++++++++++++++++++++------- include/linux/clocksource.h | 6 ++ 3 files changed, 118 insertions(+), 27 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 6a79fc4..612f2a0 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> @@ -370,8 +371,12 @@ 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_disabled ||
of_property_read_u32(np, "clock-frequency", &arch_timer_rate)) {@@ -690,28 +695,8 @@ static void __init arch_timer_common_init(void) arch_timer_arch_init(); }
-static void __init arch_timer_init(struct device_node *np) +static void __init arch_timer_init(void) {
- int i;
- if (arch_timers_present & ARCH_CP15_TIMER) {
pr_warn("arch_timer: multiple nodes in dt, skipping\n");return;- }
- arch_timers_present |= ARCH_CP15_TIMER;
- for (i = PHYS_SECURE_PPI; i < MAX_TIMER_PPI; i++)
arch_timer_ppi[i] = irq_of_parse_and_map(np, i);- arch_timer_detect_rate(NULL, np);
- /*
* If we cannot rely on firmware initializing the timer registers then* we should use the physical timers instead.*/- if (IS_ENABLED(CONFIG_ARM) &&
of_property_read_bool(np, "arm,cpu-registers-not-fw-configured"))arch_timer_use_virtual = false;- /*
- If HYP mode is available, we know that the physical timer
- has been configured to be accessible from PL1. Use it, so
@@ -730,13 +715,39 @@ static void __init arch_timer_init(struct device_node *np) } }
- arch_timer_c3stop = !of_property_read_bool(np, "always-on");
- arch_timer_register(); arch_timer_common_init();
} -CLOCKSOURCE_OF_DECLARE(armv7_arch_timer, "arm,armv7-timer", arch_timer_init); -CLOCKSOURCE_OF_DECLARE(armv8_arch_timer, "arm,armv8-timer", arch_timer_init);
+static void __init arch_timer_of_init(struct device_node *np) +{
- int i;
- if (arch_timers_present & ARCH_CP15_TIMER) {
pr_warn("arch_timer: multiple nodes in dt, skipping\n");return;- }
- arch_timers_present |= ARCH_CP15_TIMER;
- for (i = PHYS_SECURE_PPI; i < MAX_TIMER_PPI; i++)
arch_timer_ppi[i] = irq_of_parse_and_map(np, i);- arch_timer_detect_rate(NULL, np);
- arch_timer_c3stop = !of_property_read_bool(np, "always-on");
- /*
* If we cannot rely on firmware initializing the timer registers then* we should use the physical timers instead.*/- if (IS_ENABLED(CONFIG_ARM) &&
of_property_read_bool(np, "arm,cpu-registers-not-fw-configured"))arch_timer_use_virtual = false;- arch_timer_init();
+} +CLOCKSOURCE_OF_DECLARE(armv7_arch_timer, "arm,armv7-timer", arch_timer_of_init); +CLOCKSOURCE_OF_DECLARE(armv8_arch_timer, "arm,armv8-timer", arch_timer_of_init);
Hanjun,
FYI, it seems that the tree that you have rebased the patch series has an issue determining clocksource in ARM64 introduced by this commit.
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=0 b46b8a718c6e90910a1b1b0fe797be3c167e186
Here is the fix from Catalin that already went upstream:
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/drive rs/clocksource/arm_arch_timer.c?id=d6ad36913083d683aad4e02e53580c995f1a6ede
Thanks,
Suravee