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>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
arch/arm64/Kconfig | 1 +
drivers/acpi/arm64/Kconfig | 3 +
drivers/acpi/arm64/Makefile | 1 +
drivers/acpi/arm64/gtdt.c | 152 ++++++++++++++++++++++++++++++++++++++++++++
drivers/clocksource/Kconfig | 1 -
include/linux/acpi.h | 6 ++
6 files changed, 163 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index bc3f00f..0607728 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -2,6 +2,7 @@ config ARM64
def_bool y
select ACPI_CCA_REQUIRED if ACPI
select ACPI_GENERIC_GSI if ACPI
+ select ACPI_GTDT if ACPI
select ACPI_REDUCED_HARDWARE_ONLY if ACPI
select ACPI_MCFG if ACPI
select ARCH_HAS_DEVMEM_IS_ALLOWED
diff --git a/drivers/acpi/arm64/Kconfig b/drivers/acpi/arm64/Kconfig
index 4616da4..5a6f80f 100644
--- a/drivers/acpi/arm64/Kconfig
+++ b/drivers/acpi/arm64/Kconfig
@@ -4,3 +4,6 @@
config ACPI_IORT
bool
+
+config ACPI_GTDT
+ bool
diff --git a/drivers/acpi/arm64/Makefile b/drivers/acpi/arm64/Makefile
index 72331f2..1017def 100644
--- a/drivers/acpi/arm64/Makefile
+++ b/drivers/acpi/arm64/Makefile
@@ -1 +1,2 @@
obj-$(CONFIG_ACPI_IORT) += iort.o
+obj-$(CONFIG_ACPI_GTDT) += gtdt.o
diff --git a/drivers/acpi/arm64/gtdt.c b/drivers/acpi/arm64/gtdt.c
new file mode 100644
index 0000000..b24844d
--- /dev/null
+++ b/drivers/acpi/arm64/gtdt.c
@@ -0,0 +1,152 @@
+/*
+ * ARM Specific GTDT table Support
+ *
+ * Copyright (C) 2016, Linaro Ltd.
+ * Author: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
+ * Fu Wei <fu.wei@xxxxxxxxxx>
+ * Hanjun Guo <hanjun.guo@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/acpi.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+
+#include <clocksource/arm_arch_timer.h>
+
+#undef pr_fmt
+#define pr_fmt(fmt) "ACPI GTDT: " fmt
+
+struct acpi_gtdt_descriptor {
+ struct acpi_table_gtdt *gtdt;
+ void *platform_timer_start;
+ void *gtdt_end;
+};
+
+static struct acpi_gtdt_descriptor acpi_gtdt_desc __initdata;
+
+static inline void *next_platform_timer(void *platform_timer)
+{
+ struct acpi_gtdt_header *gh = platform_timer;
+
+ platform_timer += gh->length;
+ if (platform_timer < acpi_gtdt_desc.gtdt_end)
+ return platform_timer;
+
+ return NULL;
+}
+
+#define for_each_platform_timer(_g) \
+ for (_g = acpi_gtdt_desc.platform_timer_start; _g; \
+ _g = next_platform_timer(_g))
+
+static inline bool is_timer_block(void *platform_timer)
+{
+ struct acpi_gtdt_header *gh = platform_timer;
+
+ return gh->type == ACPI_GTDT_TYPE_TIMER_BLOCK;
+}
+
+static inline bool is_watchdog(void *platform_timer)
+{
+ struct acpi_gtdt_header *gh = platform_timer;
+
+ return gh->type == ACPI_GTDT_TYPE_WATCHDOG;
+}
+
+static int __init map_gt_gsi(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_gt_gsi(gtdt->secure_el1_interrupt,
+ gtdt->secure_el1_flags);
+ case PHYS_NONSECURE_PPI:
+ return map_gt_gsi(gtdt->non_secure_el1_interrupt,
+ gtdt->non_secure_el1_flags);
+ case VIRT_PPI:
+ return map_gt_gsi(gtdt->virtual_timer_interrupt,
+ gtdt->virtual_timer_flags);
+
+ case HYP_PPI:
+ return map_gt_gsi(gtdt->non_secure_el2_interrupt,
+ gtdt->non_secure_el2_flags);
+ default:
+ pr_err("Failed to map timer interrupt: invalid type.\n");
+ }
+
+ return 0;
+}
+
+/*
+ * acpi_gtdt_c3stop - got c3stop info from GTDT
+ *
+ * Returns 1 if the timer is powered in deep idle state, 0 otherwise.
+ */
+bool __init acpi_gtdt_c3stop(void)
+{
+ struct acpi_table_gtdt *gtdt = acpi_gtdt_desc.gtdt;
+
+ return !(gtdt->non_secure_el1_flags & ACPI_GTDT_ALWAYS_ON);
+}
+
+/*
+ * Get some basic info from GTDT table, and init the global variables above
+ * for all timers initialization of Generic Timer.
+ * This function does some validation on GTDT table.
+ */
+int __init acpi_gtdt_init(struct acpi_table_header *table)
+{
+ void *start;
+ struct acpi_table_gtdt *gtdt;
+
+ gtdt = container_of(table, struct acpi_table_gtdt, header);
+
+ acpi_gtdt_desc.gtdt = gtdt;
+ acpi_gtdt_desc.gtdt_end = (void *)table + table->length;
+
+ if (table->revision < 2) {
+ pr_debug("Revision:%d doesn't support Platform Timers.\n",
+ table->revision);
+ return 0;
+ }
+
+ if (!gtdt->platform_timer_count) {
+ pr_debug("No Platform Timer.\n");
+ return 0;
+ }
+
+ start = (void *)gtdt + gtdt->platform_timer_offset;
+ if (start < (void *)table + sizeof(struct acpi_table_gtdt)) {
+ pr_err(FW_BUG "Failed to retrieve timer info from firmware: invalid data.\n");
+ return -EINVAL;
+ }
+ acpi_gtdt_desc.platform_timer_start = start;
+
+ return gtdt->platform_timer_count;
+}
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index 5677886..b58d259 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -285,7 +285,6 @@ config CLKSRC_MPS2
config ARM_ARCH_TIMER
bool
select CLKSRC_OF if OF
- select CLKSRC_ACPI if ACPI
config ARM_ARCH_TIMER_EVTSTREAM
bool "Enable ARM architected timer event stream generation by default"
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index c5eaf2f..e2f9841 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -567,6 +567,12 @@ enum acpi_reconfig_event {
int acpi_reconfig_notifier_register(struct notifier_block *nb);
int acpi_reconfig_notifier_unregister(struct notifier_block *nb);
+#ifdef CONFIG_ACPI_GTDT
+int acpi_gtdt_init(struct acpi_table_header *table);
+int acpi_gtdt_map_ppi(int type);
+bool acpi_gtdt_c3stop(void);
+#endif
+
#else /* !CONFIG_ACPI */
#define acpi_disabled 1
--
2.7.4
--
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