[U-Boot] [PATCH 02/22] x86: acpi: Add Kconfig option and header file for ACPI resume

[Bin Meng]

This introduces a Kconfig option for ACPI S3 resume, as well as a
header file to include anything related to ACPI S3 resume.

Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
---

 arch/x86/Kconfig               | 12 +++++++++
 arch/x86/include/asm/acpi_s3.h | 58 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 70 insertions(+)
 create mode 100644 arch/x86/include/asm/acpi_s3.h

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index dfdd756..7ea9148 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -571,6 +571,18 @@ config GENERATE_ACPI_TABLE
 
 endmenu
 
+config HAVE_ACPI_RESUME
+	bool "Enable ACPI S3 resume"
+	help
+	  Select this to enable ACPI S3 resume. S3 is an ACPI defined sleeping
+	  state where all system context is lost except system memory. U-Boot
+	  is responsible for restore the machine state as it is before sleep.
+	  It needs restore the memory controller, not overwriting memory which
+	  is not marked as reserved. For the peripherals which lose their
+	  registers, U-Boot needs to write the original value. When everything
+	  is done, U-Boot needs to find out the wakeup vector provided by OSes
+	  and jump there.
+
 config MAX_PIRQ_LINKS
 	int
 	default 8
diff --git a/arch/x86/include/asm/acpi_s3.h b/arch/x86/include/asm/acpi_s3.h
new file mode 100644
index 0000000..6fbfc3e
--- /dev/null
+++ b/arch/x86/include/asm/acpi_s3.h
@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) 2017, Bin Meng <bmeng.cn at gmail.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef __ASM_ACPI_S3_H__
+#define __ASM_ACPI_S3_H__
+
+/* PM1_STATUS register */
+#define WAK_STS		(1 << 15)
+#define PCIEXPWAK_STS	(1 << 14)
+#define RTC_STS		(1 << 10)
+#define SLPBTN_STS	(1 << 9)
+#define PWRBTN_STS	(1 << 8)
+#define GBL_STS		(1 << 5)
+#define BM_STS		(1 << 4)
+#define TMR_STS		(1 << 0)
+
+/* PM1_CNT register */
+#define SLP_EN		(1 << 13)
+#define SLP_TYP_SHIFT	10
+#define SLP_TYP		(7 << SLP_TYP_SHIFT)
+#define SLP_TYP_S0	0
+#define SLP_TYP_S1	1
+#define SLP_TYP_S3	5
+#define SLP_TYP_S4	6
+#define SLP_TYP_S5	7
+
+enum acpi_sleep_state {
+	ACPI_S0,
+	ACPI_S1,
+	ACPI_S2,
+	ACPI_S3,
+	ACPI_S4,
+	ACPI_S5,
+};
+
+/* Given the provided PM1 control register return the ACPI sleep type */
+static inline enum acpi_sleep_state acpi_sleep_from_pm1(u32 pm1_cnt)
+{
+	switch ((pm1_cnt & SLP_TYP) >> SLP_TYP_SHIFT) {
+	case SLP_TYP_S0:
+		return ACPI_S0;
+	case SLP_TYP_S1:
+		return ACPI_S1;
+	case SLP_TYP_S3:
+		return ACPI_S3;
+	case SLP_TYP_S4:
+		return ACPI_S4;
+	case SLP_TYP_S5:
+		return ACPI_S5;
+	}
+
+	return -1;
+}
+
+#endif /* __ASM_ACPI_S3_H__ */
-- 
2.9.2