x86: baytrail: acpi: Add APIs for determining/clearing sleep state

This adds APIs for determining previous sleep state from ACPI I/O
registers, as well as clearing sleep state on BayTrail SoC.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Stefan Roese <sr@denx.de>

arch/x86/cpu/baytrail/acpi.c

@@ -8,7 +8,9 @@
 #include <cpu.h>
 #include <dm.h>
 #include <dm/uclass-internal.h>
+#include <asm/acpi_s3.h>
 #include <asm/acpi_table.h>
+#include <asm/io.h>
 #include <asm/ioapic.h>
 #include <asm/mpspec.h>
 #include <asm/tables.h>
@@ -187,3 +189,48 @@ void acpi_create_gnvs(struct acpi_global_nvs *gnvs)
 	else
 		gnvs->iuart_en = 0;
 }
+
+#ifdef CONFIG_HAVE_ACPI_RESUME
+/*
+ * The following two routines are called at a very early stage, even before
+ * FSP 2nd phase API fsp_init() is called. Registers off ACPI_BASE_ADDRESS
+ * and PMC_BASE_ADDRESS are accessed, so we need make sure the base addresses
+ * of these two blocks are programmed by either U-Boot or FSP.
+ *
+ * It has been verified that 1st phase API (see arch/x86/lib/fsp/fsp_car.S)
+ * on Intel BayTrail SoC already initializes these two base addresses so
+ * we are safe to access these registers here.
+ */
+
+enum acpi_sleep_state chipset_prev_sleep_state(void)
+{
+	u32 pm1_sts;
+	u32 pm1_cnt;
+	u32 gen_pmcon1;
+	enum acpi_sleep_state prev_sleep_state = ACPI_S0;
+
+	/* Read Power State */
+	pm1_sts = inw(ACPI_BASE_ADDRESS + PM1_STS);
+	pm1_cnt = inl(ACPI_BASE_ADDRESS + PM1_CNT);
+	gen_pmcon1 = readl(PMC_BASE_ADDRESS + GEN_PMCON1);
+
+	debug("PM1_STS = 0x%x PM1_CNT = 0x%x GEN_PMCON1 = 0x%x\n",
+	      pm1_sts, pm1_cnt, gen_pmcon1);
+
+	if (pm1_sts & WAK_STS)
+		prev_sleep_state = acpi_sleep_from_pm1(pm1_cnt);
+
+	if (gen_pmcon1 & (PWR_FLR | SUS_PWR_FLR))
+		prev_sleep_state = ACPI_S5;
+
+	return prev_sleep_state;
+}
+
+void chipset_clear_sleep_state(void)
+{
+	u32 pm1_cnt;
+
+	pm1_cnt = inl(ACPI_BASE_ADDRESS + PM1_CNT);
+	outl(pm1_cnt & ~(SLP_TYP), ACPI_BASE_ADDRESS + PM1_CNT);
+}
+#endif

arch/x86/include/asm/arch-baytrail/iomap.h

@@ -35,6 +35,27 @@
 #define PMC_BASE_ADDRESS		0xfed03000
 #define PMC_BASE_SIZE			0x400
 
+#define GEN_PMCON1			0x20
+#define  UART_EN			(1 << 24)
+#define  DISB				(1 << 23)
+#define  MEM_SR				(1 << 21)
+#define  SRS				(1 << 20)
+#define  CTS				(1 << 19)
+#define  MS4V				(1 << 18)
+#define  PWR_FLR			(1 << 16)
+#define  PME_B0_S5_DIS			(1 << 15)
+#define  SUS_PWR_FLR			(1 << 14)
+#define  WOL_EN_OVRD			(1 << 13)
+#define  DIS_SLP_X_STRCH_SUS_UP		(1 << 12)
+#define  GEN_RST_STS			(1 <<  9)
+#define  RPS				(1 <<  2)
+#define  AFTERG3_EN			(1 <<  0)
+#define GEN_PMCON2			0x24
+#define  SLPSX_STR_POL_LOCK		(1 << 18)
+#define  BIOS_PCI_EXP_EN		(1 << 10)
+#define  PWRBTN_LVL			(1 <<  9)
+#define  SMI_LOCK			(1 <<  4)
+
 /* Power Management Unit */
 #define PUNIT_BASE_ADDRESS		0xfed05000
 #define PUNIT_BASE_SIZE			0x800
@@ -62,6 +83,9 @@
 #define ACPI_BASE_ADDRESS		0x0400
 #define ACPI_BASE_SIZE			0x80
 
+#define PM1_STS				0x00
+#define PM1_CNT				0x04
+
 #define GPIO_BASE_ADDRESS		0x0500
 #define GPIO_BASE_SIZE			0x100