From: Fu Wei <fu.wei@xxxxxxxxxx>
This patch adds support for parsing arch timer in GTDT,
provides some kernel APIs to parse all the PPIs and
always-on info in GTDT and export them.
By this driver, we can simplify arm_arch_timer drivers, and
separate the ACPI GTDT knowledge from it.
Signed-off-by: Fu Wei <fu.wei@xxxxxxxxxx>
Signed-off-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
---
drivers/acpi/acpi_gtdt.c | 70 ++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/acpi.h | 6 +++++
2 files changed, 76 insertions(+)
diff --git a/drivers/acpi/acpi_gtdt.c b/drivers/acpi/acpi_gtdt.c
index 54d7644e..edb5a8c 100644
--- a/drivers/acpi/acpi_gtdt.c
+++ b/drivers/acpi/acpi_gtdt.c
@@ -16,6 +16,8 @@
#include <linux/kernel.h>
#include <linux/module.h>
+#include <clocksource/arm_arch_timer.h>
+
#undef pr_fmt
#define pr_fmt(fmt) "GTDT: " fmt
@@ -83,3 +85,71 @@ static int __init acpi_gtdt_desc_init(struct acpi_table_header *table)
return gtdt->platform_timer_count;
}
+
+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);
+}
+
+/*
+ * Map the PPIs of per-cpu arch_timer.
+ * @type: the type of PPI
+ * Returns 0 if error.
+ */
+int __init acpi_gtdt_map_ppi(int type)
+{
+ struct acpi_table_gtdt *gtdt = acpi_gtdt_desc.gtdt;
+
+ switch (type) {
+ case PHYS_SECURE_PPI:
+ return map_generic_timer_interrupt(gtdt->secure_el1_interrupt,
+ gtdt->secure_el1_flags);
+ case PHYS_NONSECURE_PPI:
+ return map_generic_timer_interrupt(gtdt->non_secure_el1_interrupt,
+ gtdt->non_secure_el1_flags);
+ case VIRT_PPI:
+ return map_generic_timer_interrupt(gtdt->virtual_timer_interrupt,
+ gtdt->virtual_timer_flags);
+
+ case HYP_PPI:
+ return map_generic_timer_interrupt(gtdt->non_secure_el2_interrupt,
+ gtdt->non_secure_el2_flags);
+ default:
+ pr_err("ppi type error.\n");
+ }
+
+ return 0;
+}
+
+/*
+ * acpi_gtdt_c3stop - got c3stop info from GTDT
+ *
+ * Returns 1 if the timer is powered in deep idle state, 0 otherwise.
+ */
+int __init acpi_gtdt_c3stop(void)
+{
+ struct acpi_table_gtdt *gtdt = acpi_gtdt_desc.gtdt;
+
+ return !(gtdt->non_secure_el1_flags & ACPI_GTDT_ALWAYS_ON);
+}
+
+int __init gtdt_arch_timer_init(struct acpi_table_header *table)
+{
+ if (table)
+ return acpi_gtdt_desc_init(table);
+
+ pr_err("table pointer error.\n");
+
+ return -EINVAL;
+}
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 288fac5..8439579 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -532,6 +532,12 @@ void acpi_walk_dep_device_list(acpi_handle handle);
struct platform_device *acpi_create_platform_device(struct acpi_device *);
#define ACPI_PTR(_ptr) (_ptr)
+#ifdef CONFIG_ACPI_GTDT
+int __init gtdt_arch_timer_init(struct acpi_table_header *table);
+int __init acpi_gtdt_map_ppi(int type);
+int __init acpi_gtdt_c3stop(void);
+#endif
+
#else /* !CONFIG_ACPI */
#define acpi_disabled 1
--
2.5.5
--
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