The PCH (Peripheral 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 <s...@chromium.org>
---
arch/x86/cpu/ivybridge/Makefile | 1 +
arch/x86/cpu/ivybridge/cpu.c | 12 ++++++++
arch/x86/cpu/ivybridge/lpc.c | 48 +++++++++++++++++++++++++++++
arch/x86/dts/link.dts | 3 +-
arch/x86/include/asm/arch-ivybridge/pch.h | 48 +++++++++++++++++++++++++++++
doc/device-tree-bindings/misc/intel-lpc.txt | 23 ++++++++++++++
6 files changed, 134 insertions(+), 1 deletion(-)
create mode 100644 arch/x86/cpu/ivybridge/lpc.c
create mode 100644 arch/x86/include/asm/arch-ivybridge/pch.h
create mode 100644 doc/device-tree-bindings/misc/intel-lpc.txt
diff --git a/arch/x86/cpu/ivybridge/Makefile b/arch/x86/cpu/ivybridge/Makefile
index dbcd4bd..ce16697 100644
--- a/arch/x86/cpu/ivybridge/Makefile
+++ b/arch/x86/cpu/ivybridge/Makefile
@@ -6,4 +6,5 @@
obj-y += car.o
obj-y += cpu.o
+obj-y += lpc.o
obj-y += sdram.o
diff --git a/arch/x86/cpu/ivybridge/cpu.c b/arch/x86/cpu/ivybridge/cpu.c
index 06f4d68..04708fb 100644
--- a/arch/x86/cpu/ivybridge/cpu.c
+++ b/arch/x86/cpu/ivybridge/cpu.c
@@ -11,14 +11,19 @@
*/
#include <common.h>
+#include <errno.h>
+#include <fdtdec.h>
#include <asm/post.h>
#include <asm/processor.h>
+#include <asm/arch/pch.h>
DECLARE_GLOBAL_DATA_PTR;
int arch_cpu_init(void)
{
+ const void *blob = gd->fdt_blob;
struct pci_controller *hose;
+ int node;
int ret;
post_code(POST_CPU_INIT);
@@ -32,6 +37,13 @@ int arch_cpu_init(void)
if (ret)
return ret;
+ node = fdtdec_next_compatible(blob, 0, COMPAT_INTEL_LPC);
+ if (node < 0)
+ return -ENOENT;
+ ret = lpc_early_init(gd->fdt_blob, node, PCH_LPC_DEV);
+ if (ret)
+ return ret;
+
return 0;
}
diff --git a/arch/x86/cpu/ivybridge/lpc.c b/arch/x86/cpu/ivybridge/lpc.c
new file mode 100644
index 0000000..621ef2c
--- /dev/null
+++ b/arch/x86/cpu/ivybridge/lpc.c
@@ -0,0 +1,48 @@
+/*
+ * From coreboot southbridge/intel/bd82x6x/lpc.c
+ *
+ * Copyright (C) 2008-2009 coresystems GmbH
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#include <common.h>
+#include <errno.h>
+#include <fdtdec.h>
+#include <pci.h>
+#include <asm/pci.h>
+#include <asm/arch/pch.h>
+
+int lpc_early_init(const void *blob, int node, pci_dev_t dev)
+{
+ struct reg_info {
+ u32 base;
+ u32 size;
+ } values[4], *ptr;
+ int count;
+ int i;
+
+ count = fdtdec_get_int_array_count(blob, node, "gen-dec",
+ (u32 *)values, sizeof(values) / sizeof(u32));
+ if (count < 0)
+ return -EINVAL;
+
+ /* Set COM1/COM2 decode range */
+ pci_write_config16(dev, LPC_IO_DEC, 0x0010);
+
+ /* Enable PS/2 Keyboard/Mouse, EC areas and COM1 */
+ pci_write_config16(dev, LPC_EN, KBC_LPC_EN | MC_LPC_EN |
+ GAMEL_LPC_EN | COMA_LPC_EN);
+
+ /* Write all registers but use 0 if we run out of data */
+ count = count * sizeof(u32) / sizeof(values[0]);
+ for (i = 0, ptr = values; i < ARRAY_SIZE(values); i++, ptr++) {
+ u32 reg = 0;
+
+ if (i < count)
+ reg = ptr->base | PCI_COMMAND_IO | (ptr->size << 16);
+ pci_write_config32(dev, LPC_GENX_DEC(i), reg);
+ }
+
+ return 0;
+}
diff --git a/arch/x86/dts/link.dts b/arch/x86/dts/link.dts
index f2fcb39..2e91631 100644
--- a/arch/x86/dts/link.dts
+++ b/arch/x86/dts/link.dts
@@ -53,9 +53,10 @@
compatible = "intel,lpc";
#address-cells = <1>;
#size-cells = <1>;
+ reg = <0x204 1 0x200 1 0x880 0x80>;
+ gen-dec = <0x800 0xfc 0x900 0xfc>;
cros-ec@200 {
compatible = "google,cros-ec";
- reg = <0x204 1 0x200 1 0x880 0x80>;
/* This describes the flash memory within the EC */
#address-cells = <1>;
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
diff --git a/doc/device-tree-bindings/misc/intel-lpc.txt
b/doc/device-tree-bindings/misc/intel-lpc.txt
new file mode 100644
index 0000000..7e1b389
--- /dev/null
+++ b/doc/device-tree-bindings/misc/intel-lpc.txt
@@ -0,0 +1,23 @@
+Intel LPC Device Binding
+========================
+
+The device tree node which describes the operation of the Intel Low Pin
+Count device is as follows:
+
+Required properties :
+- compatible = "intel,lpc"
+- gen-dec : Specifies the values for the gen-dec registers. Up to four cell
+ pairs can be provided - the first of each pair is the base address and
+ the second is the size. These are written into the GENx_DEC registers of
+ the LPC device
+
+
+Example
+-------
+
+lpc {
+ compatible = "intel,lpc";
+ #address-cells = <1>;
+ #size-cells = <1>;
+ gen-dec = <0x800 0xfc 0x900 0xfc>;
+};
--
2.1.0.rc2.206.gedb03e5
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