x86: qemu: Enable legacy IDE I/O ports decode

QEMU always decode legacy IDE I/O ports on PIIX chipset. However Linux ata_piix
driver does sanity check to see whether legacy ports decode is turned on.
To make Linux ata_piix driver happy, turn on the decode via IDE_TIMING register.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/x86/include/asm/arch-qemu/device.h b/arch/x86/include/asm/arch-qemu/device.h
new file mode 100644
index 0000000..2a8d460
--- /dev/null
+++ b/arch/x86/include/asm/arch-qemu/device.h
@@ -0,0 +1,19 @@
+/*
+ * Copyright (C) 2015, Bin Meng <bmeng.cn@gmail.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef _QEMU_DEVICE_H_
+#define _QEMU_DEVICE_H_
+
+#include <pci.h>
+
+#define QEMU_I440FX	PCI_BDF(0, 0, 0)
+#define PIIX_ISA	PCI_BDF(0, 1, 0)
+#define PIIX_IDE	PCI_BDF(0, 1, 1)
+#define PIIX_USB	PCI_BDF(0, 1, 2)
+
+#define QEMU_Q35	PCI_BDF(0, 0, 0)
+
+#endif /* _QEMU_DEVICE_H_ */
diff --git a/arch/x86/include/asm/arch-qemu/qemu.h b/arch/x86/include/asm/arch-qemu/qemu.h
index 7a9901d..5cbffff 100644
--- a/arch/x86/include/asm/arch-qemu/qemu.h
+++ b/arch/x86/include/asm/arch-qemu/qemu.h
@@ -13,6 +13,11 @@
 #define PAM_NUM			7
 #define PAM_RW			0x33
 
+/* IDE Timing Register */
+#define IDE0_TIM		0x40
+#define IDE1_TIM		0x42
+#define IDE_DECODE_EN		0x8000
+
 /* I/O Ports */
 #define CMOS_ADDR_PORT		0x70
 #define CMOS_DATA_PORT		0x71