i2c: piix4: Move i2c_piix4 macros and structures to common header

Add a separate header file to relocate the common code from the i2c_piix4
driver, allowing the AMD ASF driver to utilize the same code.

Update the MAINTAINERS file to include information about the new common
header file.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Co-developed-by: Sanket Goswami <Sanket.Goswami@amd.com>
Signed-off-by: Sanket Goswami <Sanket.Goswami@amd.com>
Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>

Author: Shyam Sundar S K

MAINTAINERS

@@ -10723,7 +10723,7 @@ F:	drivers/i2c/busses/i2c-i801.c
 F:	drivers/i2c/busses/i2c-isch.c
 F:	drivers/i2c/busses/i2c-nforce2-s4985.c
 F:	drivers/i2c/busses/i2c-nforce2.c
-F:	drivers/i2c/busses/i2c-piix4.c
+F:	drivers/i2c/busses/i2c-piix4.*
 F:	drivers/i2c/busses/i2c-sis5595.c
 F:	drivers/i2c/busses/i2c-sis630.c
 F:	drivers/i2c/busses/i2c-sis96x.c

drivers/i2c/busses/i2c-piix4.c

@@ -35,20 +35,7 @@
 #include <linux/acpi.h>
 #include <linux/io.h>
 
-
-/* PIIX4 SMBus address offsets */
-#define SMBHSTSTS	(0 + piix4_smba)
-#define SMBHSLVSTS	(1 + piix4_smba)
-#define SMBHSTCNT	(2 + piix4_smba)
-#define SMBHSTCMD	(3 + piix4_smba)
-#define SMBHSTADD	(4 + piix4_smba)
-#define SMBHSTDAT0	(5 + piix4_smba)
-#define SMBHSTDAT1	(6 + piix4_smba)
-#define SMBBLKDAT	(7 + piix4_smba)
-#define SMBSLVCNT	(8 + piix4_smba)
-#define SMBSHDWCMD	(9 + piix4_smba)
-#define SMBSLVEVT	(0xA + piix4_smba)
-#define SMBSLVDAT	(0xC + piix4_smba)
+#include "i2c-piix4.h"
 
 /* count for request_region */
 #define SMBIOSIZE	9
@@ -70,7 +57,6 @@
 #define PIIX4_BYTE		0x04
 #define PIIX4_BYTE_DATA		0x08
 #define PIIX4_WORD_DATA		0x0C
-#define PIIX4_BLOCK_DATA	0x14
 
 /* Multi-port constants */
 #define PIIX4_MAX_ADAPTERS	4
@@ -160,11 +146,6 @@ static const char *piix4_main_port_names_sb800[PIIX4_MAX_ADAPTERS] = {
 };
 static const char *piix4_aux_port_name_sb800 = " port 1";
 
-struct sb800_mmio_cfg {
-	void __iomem *addr;
-	bool use_mmio;
-};
-
 struct i2c_piix4_adapdata {
 	unsigned short smba;
 

drivers/i2c/busses/i2c-piix4.h

@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * PIIX4/SB800 SMBus Interfaces
+ *
+ * Copyright (c) 2024, Advanced Micro Devices, Inc.
+ * All Rights Reserved.
+ *
+ * Authors: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
+ *	    Sanket Goswami <Sanket.Goswami@amd.com>
+ */
+
+#ifndef I2C_PIIX4_H
+#define I2C_PIIX4_H
+
+#include <linux/types.h>
+
+/* PIIX4 SMBus address offsets */
+#define SMBHSTSTS	(0x00 + piix4_smba)
+#define SMBHSLVSTS	(0x01 + piix4_smba)
+#define SMBHSTCNT	(0x02 + piix4_smba)
+#define SMBHSTCMD	(0x03 + piix4_smba)
+#define SMBHSTADD	(0x04 + piix4_smba)
+#define SMBHSTDAT0	(0x05 + piix4_smba)
+#define SMBHSTDAT1	(0x06 + piix4_smba)
+#define SMBBLKDAT	(0x07 + piix4_smba)
+#define SMBSLVCNT	(0x08 + piix4_smba)
+#define SMBSHDWCMD	(0x09 + piix4_smba)
+#define SMBSLVEVT	(0x0A + piix4_smba)
+#define SMBSLVDAT	(0x0C + piix4_smba)
+
+/* PIIX4 constants */
+#define PIIX4_BLOCK_DATA	0x14
+
+struct sb800_mmio_cfg {
+	void __iomem *addr;
+	bool use_mmio;
+};
+
+#endif /* I2C_PIIX4_H */