ACPICA: Add support for LPIT table.

Adds header, disassembler, table compiler, and template support
for the Low Power Idle Table (LPIT).

Note that the disassembler and table compiler are not shipped in
the kernel.

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

include/acpi/actbl2.h

@@ -70,6 +70,7 @@
 #define ACPI_SIG_HPET           "HPET"	/* High Precision Event Timer table */
 #define ACPI_SIG_IBFT           "IBFT"	/* iSCSI Boot Firmware Table */
 #define ACPI_SIG_IVRS           "IVRS"	/* I/O Virtualization Reporting Structure */
+#define ACPI_SIG_LPIT           "LPIT"	/* Low Power Idle Table */
 #define ACPI_SIG_MCFG           "MCFG"	/* PCI Memory Mapped Configuration table */
 #define ACPI_SIG_MCHI           "MCHI"	/* Management Controller Host Interface table */
 #define ACPI_SIG_MTMR           "MTMR"	/* MID Timer table */
@@ -818,6 +819,70 @@ struct acpi_ivrs_memory {
 	u64 memory_length;
 };
 
+/*******************************************************************************
+ *
+ * LPIT - Low Power Idle Table
+ *
+ * Conforms to "ACPI Low Power Idle Table (LPIT) and _LPD Proposal (DRAFT)"
+ *
+ ******************************************************************************/
+
+struct acpi_table_lpit {
+	struct acpi_table_header header;	/* Common ACPI table header */
+};
+
+/* LPIT subtable header */
+
+struct acpi_lpit_header {
+	u32 type;		/* Subtable type */
+	u32 length;		/* Subtable length */
+	u16 unique_id;
+	u16 reserved;
+	u32 flags;
+};
+
+/* Values for subtable Type above */
+
+enum acpi_lpit_type {
+	ACPI_LPIT_TYPE_NATIVE_CSTATE = 0x00,
+	ACPI_LPIT_TYPE_SIMPLE_IO = 0x01
+};
+
+/* Masks for Flags field above  */
+
+#define ACPI_LPIT_STATE_DISABLED    (1)
+#define ACPI_LPIT_NO_COUNTER        (1<<1)
+
+/*
+ * LPIT subtables, correspond to Type in struct acpi_lpit_header
+ */
+
+/* 0x00: Native C-state instruction based LPI structure */
+
+struct acpi_lpit_native {
+	struct acpi_lpit_header header;
+	struct acpi_generic_address entry_trigger;
+	u32 residency;
+	u32 latency;
+	struct acpi_generic_address residency_counter;
+	u64 counter_frequency;
+};
+
+/* 0x01: Simple I/O based LPI structure */
+
+struct acpi_lpit_io {
+	struct acpi_lpit_header header;
+	struct acpi_generic_address entry_trigger;
+	u32 trigger_action;
+	u64 trigger_value;
+	u64 trigger_mask;
+	struct acpi_generic_address minimum_idle_state;
+	u32 residency;
+	u32 latency;
+	struct acpi_generic_address residency_counter;
+	u64 counter_frequency;
+};
+
 /*******************************************************************************
  *
  * MCFG - PCI Memory Mapped Configuration table and sub-table