+#define SANDBOX_I2C_TEST_ADDR 0x59
+
+#define SANDBOX_PCI_VENDOR_ID 0x1234
+#define SANDBOX_PCI_DEVICE_ID 0x5678
+#define SANDBOX_PCI_CLASS_CODE PCI_CLASS_CODE_COMM
+#define SANDBOX_PCI_CLASS_SUB_CODE PCI_CLASS_SUB_CODE_COMM_SERIAL
+
+#define PCI_CAP_ID_PM_OFFSET 0x50
+#define PCI_CAP_ID_EXP_OFFSET 0x60
+#define PCI_CAP_ID_MSIX_OFFSET 0x70
+
+#define PCI_EXT_CAP_ID_ERR_OFFSET 0x100
+#define PCI_EXT_CAP_ID_VC_OFFSET 0x200
+#define PCI_EXT_CAP_ID_DSN_OFFSET 0x300
+
+/* Useful for PCI_VDEVICE() macro */
+#define PCI_VENDOR_ID_SANDBOX SANDBOX_PCI_VENDOR_ID
+#define SWAP_CASE_DRV_DATA 0x55aa
+
+#define SANDBOX_CLK_RATE 32768
+
+/* System controller driver data */
+enum {
+ SYSCON0 = 32,
+ SYSCON1,
+
+ SYSCON_COUNT
+};
+
+/**
+ * sandbox_i2c_set_test_mode() - set test mode for running unit tests
+ *
+ * See sandbox_i2c_xfer() for the behaviour changes.
+ *
+ * @bus: sandbox I2C bus to adjust
+ * @test_mode: true to select test mode, false to run normally
+ */
+void sandbox_i2c_set_test_mode(struct udevice *bus, bool test_mode);