x86: ivybridge: Add early LPC init so that serial works
The PCH (Platform Controller Hub) includes an LPC (Low Pin Count) device
which provides a serial port. This is accessible on Chromebooks, so enable
it early in the boot process.
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/x86/include/asm/arch-ivybridge/pch.h b/arch/x86/include/asm/arch-ivybridge/pch.h
new file mode 100644
index 0000000..26ddeab
--- /dev/null
+++ b/arch/x86/include/asm/arch-ivybridge/pch.h
@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) 2014 Google, Inc
+ *
+ * From Coreboot src/southbridge/intel/bd82x6x/pch.h
+ *
+ * Copyright (C) 2008-2009 coresystems GmbH
+ * Copyright (C) 2012 The Chromium OS Authors. All rights reserved.
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#ifndef _ASM_ARCH_PCH_H
+#define _ASM_ARCH_PCH_H
+
+#include <pci.h>
+
+/* PCI Configuration Space (D31:F0): LPC */
+#define PCH_LPC_DEV PCI_BDF(0, 0x1f, 0)
+
+#define LPC_IO_DEC 0x80 /* IO Decode Ranges Register */
+#define LPC_EN 0x82 /* LPC IF Enables Register */
+#define CNF2_LPC_EN (1 << 13) /* 0x4e/0x4f */
+#define CNF1_LPC_EN (1 << 12) /* 0x2e/0x2f */
+#define MC_LPC_EN (1 << 11) /* 0x62/0x66 */
+#define KBC_LPC_EN (1 << 10) /* 0x60/0x64 */
+#define GAMEH_LPC_EN (1 << 9) /* 0x208/0x20f */
+#define GAMEL_LPC_EN (1 << 8) /* 0x200/0x207 */
+#define FDD_LPC_EN (1 << 3) /* LPC_IO_DEC[12] */
+#define LPT_LPC_EN (1 << 2) /* LPC_IO_DEC[9:8] */
+#define COMB_LPC_EN (1 << 1) /* LPC_IO_DEC[6:4] */
+#define COMA_LPC_EN (1 << 0) /* LPC_IO_DEC[3:2] */
+#define LPC_GEN1_DEC 0x84 /* LPC IF Generic Decode Range 1 */
+#define LPC_GEN2_DEC 0x88 /* LPC IF Generic Decode Range 2 */
+#define LPC_GEN3_DEC 0x8c /* LPC IF Generic Decode Range 3 */
+#define LPC_GEN4_DEC 0x90 /* LPC IF Generic Decode Range 4 */
+#define LPC_GENX_DEC(x) (0x84 + 4 * (x))
+
+/**
+ * lpc_early_init() - set up LPC serial ports and other early things
+ *
+ * @blob: Device tree blob
+ * @node: Offset of LPC node
+ * @dev: PCH PCI device containing the LPC
+ * @return 0 if OK, -ve on error
+ */
+int lpc_early_init(const void *blob, int node, pci_dev_t dev);
+
+#endif