[coreboot-gerrit] New patch to review for coreboot: intel/fsp_broadwell_de: Do not use hard coded SCI IRQ for ACPI

[Werner Zeh (werner.zeh@siemens.com)]

Werner Zeh (werner.zeh at siemens.com) just uploaded a new patch set to gerrit, which you can find at https://review.coreboot.org/15548

-gerrit

commit 16efb9d129ad2d025f0cdc1326a34422ec584c94
Author: Werner Zeh <werner.zeh at siemens.com>
Date:   Wed Jul 6 12:58:57 2016 +0200

    intel/fsp_broadwell_de: Do not use hard coded SCI IRQ for ACPI
    
    The SCI interrupt can be routed to different IRQs using ACPI control
    register. Instead of using hard coded IRQ9 for ACPI table generation
    read back the register and return the used IRQ number. This way SCI IRQ
    can be modified (e.g. for a given mainboard) and ACPI tables will
    remain consistent.
    
    Change-Id: I534fc69eb1df28cd8d733d1ac6b2081d2dcf7511
    Signed-off-by: Werner Zeh <werner.zeh at siemens.com>
---
 src/soc/intel/fsp_broadwell_de/acpi.c            | 30 +++++++++++++++++++++++-
 src/soc/intel/fsp_broadwell_de/include/soc/irq.h | 10 ++++++++
 2 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/src/soc/intel/fsp_broadwell_de/acpi.c b/src/soc/intel/fsp_broadwell_de/acpi.c
index afa4048..1e08868 100644
--- a/src/soc/intel/fsp_broadwell_de/acpi.c
+++ b/src/soc/intel/fsp_broadwell_de/acpi.c
@@ -78,7 +78,35 @@ static acpi_cstate_t cstate_map[] = {
 
 static int acpi_sci_irq(void)
 {
-	return 9;
+	uint8_t actl = 0;
+	static uint8_t sci_irq = 0;
+	device_t dev = dev_find_slot(0, PCI_DEVFN(LPC_DEV, LPC_FUNC));
+
+	/* If this function was already called, just return the stored value. */
+	if (sci_irq)
+		return sci_irq;
+	/* Get contents of ACPI control register. */
+	actl = pci_read_config8(dev, ACPI_CNTL_OFFSET) & SCIS_MASK;
+	/* Determine how SCI is routed. */
+	switch (actl) {
+	case SCIS_IRQ9:
+	case SCIS_IRQ10:
+	case SCIS_IRQ11:
+		sci_irq = actl + 9;
+		break;
+	case SCIS_IRQ20:
+	case SCIS_IRQ21:
+	case SCIS_IRQ22:
+	case SCIS_IRQ23:
+		sci_irq = actl - SCIS_IRQ20 + 20;
+		break;
+	default:
+		printk(BIOS_DEBUG, "Invalid SCI route! Defaulting to IRQ9.\n");
+		sci_irq = 9;
+		break;
+	}
+	printk(BIOS_DEBUG, "SCI is IRQ%d\n", sci_irq);
+	return sci_irq;
 }
 
 void acpi_create_intel_hpet(acpi_hpet_t *hpet)
diff --git a/src/soc/intel/fsp_broadwell_de/include/soc/irq.h b/src/soc/intel/fsp_broadwell_de/include/soc/irq.h
index ea04326..1344f3b 100644
--- a/src/soc/intel/fsp_broadwell_de/include/soc/irq.h
+++ b/src/soc/intel/fsp_broadwell_de/include/soc/irq.h
@@ -51,6 +51,16 @@
 #define PIRQG 6
 #define PIRQH 7
 
+#define ACPI_CNTL_OFFSET	0x44
+#define SCIS_MASK		0x07
+#define SCIS_IRQ9		0x00
+#define SCIS_IRQ10		0x01
+#define SCIS_IRQ11		0x02
+#define SCIS_IRQ20		0x04
+#define SCIS_IRQ21		0x05
+#define SCIS_IRQ22		0x06
+#define SCIS_IRQ23		0x07
+
 /* In each mainboard directory there should exist a header file irqroute.h that
  * defines the PCI_DEV_PIRQ_ROUTES and PIRQ_PIC_ROUTES macros which
  * consist of PCI_DEV_PIRQ_ROUTE and PIRQ_PIC entries. */