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authorHanjun Guo <hanjun.guo@linaro.org>2015-03-24 17:02:50 +0300
committerWill Deacon <will.deacon@arm.com>2015-03-26 18:13:07 +0300
commitb09ca1ecf6d499d5a33f978c905d2fbcc79b55d9 (patch)
treea9b807414433367bcf647a38d7d3e5623e236ace /drivers/clocksource/arm_arch_timer.c
parentd60fc3892c4de4a25658786f941690462c5a5bab (diff)
downloadlinux-b09ca1ecf6d499d5a33f978c905d2fbcc79b55d9.tar.xz
clocksource / arch_timer: Parse GTDT to initialize arch timer
Using the information presented by GTDT (Generic Timer Description Table) to initialize the arch timer (not memory-mapped). CC: Daniel Lezcano <daniel.lezcano@linaro.org> CC: Thomas Gleixner <tglx@linutronix.de> Originally-by: Amit Daniel Kachhap <amit.daniel@samsung.com> Tested-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com> Tested-by: Yijing Wang <wangyijing@huawei.com> Tested-by: Mark Langsdorf <mlangsdo@redhat.com> Tested-by: Jon Masters <jcm@redhat.com> Tested-by: Timur Tabi <timur@codeaurora.org> Tested-by: Robert Richter <rrichter@cavium.com> Acked-by: Robert Richter <rrichter@cavium.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Reviewed-by: Grant Likely <grant.likely@linaro.org> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'drivers/clocksource/arm_arch_timer.c')
-rw-r--r--drivers/clocksource/arm_arch_timer.c132
1 files changed, 105 insertions, 27 deletions
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index a3025e7ae35f..ea62fc79e1e8 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -22,6 +22,7 @@
#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>
@@ -371,8 +372,12 @@ 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)) {
if (cntbase)
arch_timer_rate = readl_relaxed(cntbase + CNTFRQ);
else
@@ -691,28 +696,8 @@ 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
@@ -731,13 +716,39 @@ 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);
static void __init arch_timer_mem_init(struct device_node *np)
{
@@ -804,3 +815,70 @@ static void __init arch_timer_mem_init(struct device_node *np)
}
CLOCKSOURCE_OF_DECLARE(armv7_arch_timer_mem, "arm,armv7-timer-mem",
arch_timer_mem_init);
+
+#ifdef CONFIG_ACPI
+static int __init map_generic_timer_interrupt(u32 interrupt, u32 flags)
+{
+ int trigger, polarity;
+
+ if (!interrupt)
+ return 0;
+
+ trigger = (flags & ACPI_GTDT_INTERRUPT_MODE) ? ACPI_EDGE_SENSITIVE
+ : ACPI_LEVEL_SENSITIVE;
+
+ polarity = (flags & ACPI_GTDT_INTERRUPT_POLARITY) ? ACPI_ACTIVE_LOW
+ : ACPI_ACTIVE_HIGH;
+
+ return acpi_register_gsi(NULL, interrupt, trigger, polarity);
+}
+
+/* Initialize per-processor generic timer */
+static int __init arch_timer_acpi_init(struct acpi_table_header *table)
+{
+ struct acpi_table_gtdt *gtdt;
+
+ if (arch_timers_present & ARCH_CP15_TIMER) {
+ pr_warn("arch_timer: already initialized, skipping\n");
+ return -EINVAL;
+ }
+
+ gtdt = container_of(table, struct acpi_table_gtdt, header);
+
+ arch_timers_present |= ARCH_CP15_TIMER;
+
+ arch_timer_ppi[PHYS_SECURE_PPI] =
+ map_generic_timer_interrupt(gtdt->secure_el1_interrupt,
+ gtdt->secure_el1_flags);
+
+ arch_timer_ppi[PHYS_NONSECURE_PPI] =
+ map_generic_timer_interrupt(gtdt->non_secure_el1_interrupt,
+ gtdt->non_secure_el1_flags);
+
+ arch_timer_ppi[VIRT_PPI] =
+ map_generic_timer_interrupt(gtdt->virtual_timer_interrupt,
+ gtdt->virtual_timer_flags);
+
+ arch_timer_ppi[HYP_PPI] =
+ map_generic_timer_interrupt(gtdt->non_secure_el2_interrupt,
+ gtdt->non_secure_el2_flags);
+
+ /* Get the frequency from CNTFRQ */
+ arch_timer_detect_rate(NULL, NULL);
+
+ /* Always-on capability */
+ arch_timer_c3stop = !(gtdt->non_secure_el1_flags & ACPI_GTDT_ALWAYS_ON);
+
+ arch_timer_init();
+ return 0;
+}
+
+/* Initialize all the generic timers presented in GTDT */
+void __init acpi_generic_timer_init(void)
+{
+ if (acpi_disabled)
+ return;
+
+ acpi_table_parse(ACPI_SIG_GTDT, arch_timer_acpi_init);
+}
+#endif