From d4e61f505b8fd8662142b6e27ef443f88f73176e Mon Sep 17 00:00:00 2001
From: Bin Meng <bmeng.cn@gmail.com>
Date: Sat, 7 May 2016 07:46:14 -0700
Subject: [PATCH] x86: irq: Enable SCI on IRQ9

By default SCI is disabled after power on. ACTL is the register to
enable SCI and route it to PIC/APIC. To support both ACPI in PIC
mode and APIC mode, configure SCI to use IRQ9.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Tested-by: Stefan Roese <sr@denx.de>
---
 arch/x86/cpu/irq.c                            | 22 +++++++++++++++++++
 arch/x86/include/asm/irq.h                    |  4 ++++
 .../misc/intel,irq-router.txt                 |  5 +++++
 3 files changed, 31 insertions(+)

diff --git a/arch/x86/cpu/irq.c b/arch/x86/cpu/irq.c
index 7586fc2b0c..86183b034e 100644
--- a/arch/x86/cpu/irq.c
+++ b/arch/x86/cpu/irq.c
@@ -147,6 +147,9 @@ static int create_pirq_routing_table(struct udevice *dev)
 		priv->ibase &= ~0xf;
 	}
 
+	priv->actl_8bit = fdtdec_get_bool(blob, node, "intel,actl-8bit");
+	priv->actl_addr = fdtdec_get_int(blob, node, "intel,actl-addr", 0);
+
 	cell = fdt_getprop(blob, node, "intel,pirq-routing", &len);
 	if (!cell || len % sizeof(struct pirq_routing))
 		return -EINVAL;
@@ -216,6 +219,22 @@ static int create_pirq_routing_table(struct udevice *dev)
 	return 0;
 }
 
+static void irq_enable_sci(struct udevice *dev)
+{
+	struct irq_router *priv = dev_get_priv(dev);
+
+	if (priv->actl_8bit) {
+		/* Bit7 must be turned on to enable ACPI */
+		dm_pci_write_config8(dev->parent, priv->actl_addr, 0x80);
+	} else {
+		/* Write 0 to enable SCI on IRQ9 */
+		if (priv->config == PIRQ_VIA_PCI)
+			dm_pci_write_config32(dev->parent, priv->actl_addr, 0);
+		else
+			writel(0, priv->ibase + priv->actl_addr);
+	}
+}
+
 int irq_router_common_init(struct udevice *dev)
 {
 	int ret;
@@ -229,6 +248,9 @@ int irq_router_common_init(struct udevice *dev)
 	pirq_route_irqs(dev, pirq_routing_table->slots,
 			get_irq_slot_count(pirq_routing_table));
 
+	if (IS_ENABLED(CONFIG_GENERATE_ACPI_TABLE))
+		irq_enable_sci(dev);
+
 	return 0;
 }
 
diff --git a/arch/x86/include/asm/irq.h b/arch/x86/include/asm/irq.h
index 5b9e673763..ddb529e581 100644
--- a/arch/x86/include/asm/irq.h
+++ b/arch/x86/include/asm/irq.h
@@ -34,6 +34,8 @@ enum pirq_config {
  *		IRQ N is available to be routed
  * @lb_bdf:	irq router's PCI bus/device/function number encoding
  * @ibase:	IBASE register block base address
+ * @actl_8bit:	ACTL register width is 8-bit (for ICH series chipset)
+ * @actl_addr:	ACTL register offset
  */
 struct irq_router {
 	int config;
@@ -41,6 +43,8 @@ struct irq_router {
 	u16 irq_mask;
 	u32 bdf;
 	u32 ibase;
+	bool actl_8bit;
+	int actl_addr;
 };
 
 struct pirq_routing {
diff --git a/doc/device-tree-bindings/misc/intel,irq-router.txt b/doc/device-tree-bindings/misc/intel,irq-router.txt
index e4d8ead2ee..04ad34654c 100644
--- a/doc/device-tree-bindings/misc/intel,irq-router.txt
+++ b/doc/device-tree-bindings/misc/intel,irq-router.txt
@@ -14,6 +14,11 @@ Required properties :
       "ibase": IRQ routing is in the memory-mapped IBASE register block
 - intel,ibase-offset : IBASE register offset in the interrupt router's PCI
     configuration space, required only if intel,pirq-config = "ibase".
+- intel,actl-8bit : If ACTL (ACPI control) register width is 8-bit, this must
+    be specified. The 8-bit ACTL register is seen on ICH series chipset, like
+    ICH9/Panther Point/etc. On Atom chipset it is a 32-bit register.
+- intel,actl-addr : ACTL (ACPI control) register offset. ACTL can be either
+    in the interrupt router's PCI configuration space, or IBASE.
 - intel,pirq-link : Specifies the PIRQ link information with two cells. The
     first cell is the register offset that controls the first PIRQ link routing.
     The second cell is the total number of PIRQ links the router supports.