x86: quark: Add routines to access message bus registers

In the Quark SoC, some chipset commands are accomplished by utilizing
the internal message network within the host bridge (D0:F0). Accesses
to this network are accomplished by populating the message control
register (MCR), Message Control Register eXtension (MCRX) and the
message data register (MDR).

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>

arch/x86/cpu/quark/msg_port.c

@@ -0,0 +1,77 @@
+/*
+ * Copyright (C) 2015, Bin Meng <bmeng.cn@gmail.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <pci.h>
+#include <asm/arch/device.h>
+#include <asm/arch/msg_port.h>
+
+void msg_port_setup(int op, int port, int reg)
+{
+	pci_write_config_dword(QUARK_HOST_BRIDGE, MSG_CTRL_REG,
+			       (((op) << 24) | ((port) << 16) |
+			       (((reg) << 8) & 0xff00) | MSG_BYTE_ENABLE));
+}
+
+u32 msg_port_read(u8 port, u32 reg)
+{
+	u32 value;
+
+	pci_write_config_dword(QUARK_HOST_BRIDGE, MSG_CTRL_EXT_REG,
+			       reg & 0xffffff00);
+	msg_port_setup(MSG_OP_READ, port, reg);
+	pci_read_config_dword(QUARK_HOST_BRIDGE, MSG_DATA_REG, &value);
+
+	return value;
+}
+
+void msg_port_write(u8 port, u32 reg, u32 value)
+{
+	pci_write_config_dword(QUARK_HOST_BRIDGE, MSG_DATA_REG, value);
+	pci_write_config_dword(QUARK_HOST_BRIDGE, MSG_CTRL_EXT_REG,
+			       reg & 0xffffff00);
+	msg_port_setup(MSG_OP_WRITE, port, reg);
+}
+
+u32 msg_port_alt_read(u8 port, u32 reg)
+{
+	u32 value;
+
+	pci_write_config_dword(QUARK_HOST_BRIDGE, MSG_CTRL_EXT_REG,
+			       reg & 0xffffff00);
+	msg_port_setup(MSG_OP_ALT_READ, port, reg);
+	pci_read_config_dword(QUARK_HOST_BRIDGE, MSG_DATA_REG, &value);
+
+	return value;
+}
+
+void msg_port_alt_write(u8 port, u32 reg, u32 value)
+{
+	pci_write_config_dword(QUARK_HOST_BRIDGE, MSG_DATA_REG, value);
+	pci_write_config_dword(QUARK_HOST_BRIDGE, MSG_CTRL_EXT_REG,
+			       reg & 0xffffff00);
+	msg_port_setup(MSG_OP_ALT_WRITE, port, reg);
+}
+
+u32 msg_port_io_read(u8 port, u32 reg)
+{
+	u32 value;
+
+	pci_write_config_dword(QUARK_HOST_BRIDGE, MSG_CTRL_EXT_REG,
+			       reg & 0xffffff00);
+	msg_port_setup(MSG_OP_IO_READ, port, reg);
+	pci_read_config_dword(QUARK_HOST_BRIDGE, MSG_DATA_REG, &value);
+
+	return value;
+}
+
+void msg_port_io_write(u8 port, u32 reg, u32 value)
+{
+	pci_write_config_dword(QUARK_HOST_BRIDGE, MSG_DATA_REG, value);
+	pci_write_config_dword(QUARK_HOST_BRIDGE, MSG_CTRL_EXT_REG,
+			       reg & 0xffffff00);
+	msg_port_setup(MSG_OP_IO_WRITE, port, reg);
+}

arch/x86/include/asm/arch-quark/msg_port.h

@@ -0,0 +1,106 @@
+/*
+ * Copyright (C) 2015, Bin Meng <bmeng.cn@gmail.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef _QUARK_MSG_PORT_H_
+#define _QUARK_MSG_PORT_H_
+
+/*
+ * In the Quark SoC, some chipset commands are accomplished by utilizing
+ * the internal message network within the host bridge (D0:F0). Accesses
+ * to this network are accomplished by populating the message control
+ * register (MCR), Message Control Register eXtension (MCRX) and the
+ * message data register (MDR).
+ */
+#define MSG_CTRL_REG		0xd0	/* Message Control Register */
+#define MSG_DATA_REG		0xd4	/* Message Data Register */
+#define MSG_CTRL_EXT_REG	0xd8	/* Message Control Register EXT */
+
+/* Normal Read/Write OpCodes */
+#define MSG_OP_READ		0x10
+#define MSG_OP_WRITE		0x11
+
+/* Alternative Read/Write OpCodes */
+#define MSG_OP_ALT_READ		0x06
+#define MSG_OP_ALT_WRITE	0x07
+
+/* IO Read/Write OpCodes */
+#define MSG_OP_IO_READ		0x02
+#define MSG_OP_IO_WRITE		0x03
+
+/* All byte enables */
+#define MSG_BYTE_ENABLE		0xf0
+
+#ifndef __ASSEMBLY__
+
+/**
+ * msg_port_setup - set up the message port control register
+ *
+ * @op:     message bus access opcode
+ * @port:   port number on the message bus
+ * @reg:    register number within a port
+ */
+void msg_port_setup(int op, int port, int reg);
+
+/**
+ * msg_port_read - read a message port register using normal opcode
+ *
+ * @port:   port number on the message bus
+ * @reg:    register number within a port
+ *
+ * @return: message port register value
+ */
+u32 msg_port_read(u8 port, u32 reg);
+
+/**
+ * msg_port_write - write a message port register using normal opcode
+ *
+ * @port:   port number on the message bus
+ * @reg:    register number within a port
+ * @value:  register value to write
+ */
+void msg_port_write(u8 port, u32 reg, u32 value);
+
+/**
+ * msg_port_alt_read - read a message port register using alternative opcode
+ *
+ * @port:   port number on the message bus
+ * @reg:    register number within a port
+ *
+ * @return: message port register value
+ */
+u32 msg_port_alt_read(u8 port, u32 reg);
+
+/**
+ * msg_port_alt_write - write a message port register using alternative opcode
+ *
+ * @port:   port number on the message bus
+ * @reg:    register number within a port
+ * @value:  register value to write
+ */
+void msg_port_alt_write(u8 port, u32 reg, u32 value);
+
+/**
+ * msg_port_io_read - read a message port register using I/O opcode
+ *
+ * @port:   port number on the message bus
+ * @reg:    register number within a port
+ *
+ * @return: message port register value
+ */
+u32 msg_port_io_read(u8 port, u32 reg);
+
+/**
+ * msg_port_io_write - write a message port register using I/O opcode
+ *
+ * @port:   port number on the message bus
+ * @reg:    register number within a port
+ * @value:  register value to write
+ */
+void msg_port_io_write(u8 port, u32 reg, u32 value);
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* _QUARK_MSG_PORT_H_ */