[PATCH v7 4/9] acpi/arm64: Add GTDT table parse driver

[fu.wei@linaro.org (fu.wei at linaro.org)]

From: Fu Wei <fu.wei@linaro.org>

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@linaro.org>
Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
---
 drivers/acpi/Kconfig           |   5 ++
 drivers/acpi/Makefile          |   1 +
 drivers/acpi/arm64/Kconfig     |  15 ++++
 drivers/acpi/arm64/Makefile    |   1 +
 drivers/acpi/arm64/acpi_gtdt.c | 170 +++++++++++++++++++++++++++++++++++++++++
 include/linux/acpi.h           |   6 ++
 6 files changed, 198 insertions(+)

diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index b7e2e77..1cdc7d2 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -521,4 +521,9 @@ config XPOWER_PMIC_OPREGION
 
 endif
 
+if ARM64
+source "drivers/acpi/arm64/Kconfig"
+
+endif
+
 endif	# ACPI
diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index 251ce85..1a94ff7 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -99,5 +99,6 @@ obj-$(CONFIG_ACPI_EXTLOG)	+= acpi_extlog.o
 obj-$(CONFIG_PMIC_OPREGION)	+= pmic/intel_pmic.o
 obj-$(CONFIG_CRC_PMIC_OPREGION) += pmic/intel_pmic_crc.o
 obj-$(CONFIG_XPOWER_PMIC_OPREGION) += pmic/intel_pmic_xpower.o
+obj-$(CONFIG_ARM64)	+= arm64/
 
 video-objs			+= acpi_video.o video_detect.o
diff --git a/drivers/acpi/arm64/Kconfig b/drivers/acpi/arm64/Kconfig
new file mode 100644
index 0000000..ff5c253
--- /dev/null
+++ b/drivers/acpi/arm64/Kconfig
@@ -0,0 +1,15 @@
+#
+# ACPI Configuration for ARM64
+#
+
+menu "The ARM64-specific ACPI Support"
+
+config ACPI_GTDT
+	bool "ACPI GTDT table Support"
+	help
+	  GTDT (Generic Timer Description Table) provides information
+	  for per-processor timers and Platform (memory-mapped) timers
+	  for ARM platforms. Select this option to provide information
+	  needed for the timers init.
+
+endmenu
diff --git a/drivers/acpi/arm64/Makefile b/drivers/acpi/arm64/Makefile
new file mode 100644
index 0000000..466de6b
--- /dev/null
+++ b/drivers/acpi/arm64/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_ACPI_GTDT)		+= acpi_gtdt.o
diff --git a/drivers/acpi/arm64/acpi_gtdt.c b/drivers/acpi/arm64/acpi_gtdt.c
new file mode 100644
index 0000000..9ee977d
--- /dev/null
+++ b/drivers/acpi/arm64/acpi_gtdt.c
@@ -0,0 +1,170 @@
+/*
+ * ARM Specific GTDT table Support
+ *
+ * Copyright (C) 2016, Linaro Ltd.
+ * Author: Daniel Lezcano <daniel.lezcano@linaro.org>
+ *         Fu Wei <fu.wei@linaro.org>
+ *         Hanjun Guo <hanjun.guo@linaro.org>
+ *
+ * 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 <linux/module.h>
+
+#include <clocksource/arm_arch_timer.h>
+
+#undef pr_fmt
+#define pr_fmt(fmt) "GTDT: " fmt
+
+typedef struct {
+	struct acpi_table_gtdt *gtdt;
+	void *platform_timer_start;
+	void *gtdt_end;
+} acpi_gtdt_desc_t;
+
+static acpi_gtdt_desc_t 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;
+
+	if (gh->type == ACPI_GTDT_TYPE_TIMER_BLOCK)
+		return true;
+
+	return false;
+}
+
+static inline bool is_watchdog(void *platform_timer)
+{
+	struct acpi_gtdt_header *gh = platform_timer;
+
+	if (gh->type == ACPI_GTDT_TYPE_WATCHDOG)
+		return true;
+
+	return false;
+}
+
+/*
+ * 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.
+ */
+static int __init acpi_gtdt_desc_init(struct acpi_table_header *table)
+{
+	struct acpi_table_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_info("Revision:%d doesn't support Platform Timers.\n",
+			table->revision);
+		return 0;
+	}
+
+	if (!gtdt->platform_timer_count) {
+		pr_info("No Platform Timer.\n");
+		return 0;
+	}
+
+	acpi_gtdt_desc.platform_timer_start = (void *)gtdt +
+					      gtdt->platform_timer_offset;
+	if (acpi_gtdt_desc.platform_timer_start <
+	    (void *)table + sizeof(struct acpi_table_gtdt)) {
+		pr_err(FW_BUG "Platform Timer pointer error.\n");
+		acpi_gtdt_desc.platform_timer_start = NULL;
+		return -EINVAL;
+	}
+
+	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