1 files changed, 95 insertions, 0 deletions
diff --git a/src/soc/intel/baytrail/int15.c b/src/soc/intel/baytrail/int15.c
new file mode 100644
index 0000000000..62abbc11a6
--- /dev/null
+++ b/src/soc/intel/baytrail/int15.c
@@ -0,0 +1,95 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <arch/interrupt.h>
+#include <console/console.h>
+#include <soc/int15.h>
+#include <x86emu/x86emu.h>
+
+static int int15_handler(void)
+{
+	int res = 1;
+
+	printk(BIOS_DEBUG, "%s: AX=%04x BX=%04x CX=%04x DX=%04x\n",
+	       __func__, X86_AX, X86_BX, X86_CX, X86_DX);
+
+	switch (X86_AX) {
+	case 0x5f34:
+		/*
+		 * Set Panel Fitting Hook:
+		 *  bit 2 = Graphics Stretching
+		 *  bit 1 = Text Stretching
+		 *  bit 0 = Centering (do not set with bit1 or bit2)
+		 *  0     = video BIOS default
+		 */
+		X86_AX = 0x005f;
+		X86_CX = 0x0001;
+		res = 1;
+		break;
+	case 0x5f35:
+		/*
+		 * Boot Display Device Hook:
+		 *  bit 0 = CRT
+		 *  bit 1 = TV
+		 *  bit 2 = EFP (HDMI)
+		 *  bit 3 = LFP (eDP)*
+		 *  bit 4 = CRT2
+		 *  bit 5 = TV2
+		 *  bit 6 = EFP2
+		 *  bit 7 = LFP2
+		 */
+		X86_AX = 0x005f;
+		X86_CX = 0x0008;
+		res = 1;
+		break;
+	case 0x5f51:
+		/*
+		 * Hook to select active LFP configuration:
+		 *  00h = No LVDS, VBIOS does not enable LVDS
+		 *  01h = Int-LVDS, LFP driven by integrated LVDS decoder
+		 *  02h = SVDO-LVDS, LFP driven by SVDO decoder
+		 *  03h = eDP, LFP Driven by Int-DisplayPort encoder
+		 */
+		X86_AX = 0x005f;
+		X86_CX = 0x0003;
+		res = 1;
+		break;
+	case 0x5f70:
+		switch ((X86_CX >> 8) & 0xff) {
+		case 0:
+			/* Get Mux */
+			X86_AX = 0x005f;
+			X86_CX = 0x0000;
+			res = 1;
+			break;
+		case 1:
+			/* Set Mux */
+			X86_AX = 0x005f;
+			X86_CX = 0x0000;
+			res = 1;
+			break;
+		case 2:
+			/* Get SG/Non-SG mode */
+			X86_AX = 0x005f;
+			X86_CX = 0x0000;
+			res = 1;
+			break;
+		default:
+			/* Interrupt was not handled */
+			printk(BIOS_DEBUG,
+			       "Unknown INT15 5f70 function: 0x%02x\n",
+				((X86_CX >> 8) & 0xff));
+			break;
+		}
+		break;
+
+	default:
+		printk(BIOS_DEBUG, "Unknown INT15 function %04x!\n", X86_AX);
+		break;
+	}
+	return res;
+}
+
+void install_baytrail_vga_int15_handler(void)
+{
+	mainboard_interrupt_handlers(0x15, &int15_handler);
+}