[PATCH] Determine SCx200 CB address at run-time

The current SCx200 drivers use a fixed base address of 0x9000 for the
Configuration Block, but some systems (at least the Soekris net4801) uses a
base address of 0x6000.  This patch first tries the fixed address then - if
no configuration block could be found - tries the address written to the
Configuration Block Address Scratchpad register by the BIOS.
Signed-off-by: Henrik Brix Andersen <brix@gentoo.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/i386/kernel/scx200.c

@@ -13,6 +13,9 @@
 
 #include <linux/scx200.h>
 
+/* Verify that the configuration block really is there */
+#define scx200_cb_probe(base) (inw((base) + SCx200_CBA) == (base))
+
 #define NAME "scx200"
 
 MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");
@@ -22,9 +25,13 @@ MODULE_LICENSE("GPL");
 unsigned scx200_gpio_base = 0;
 long scx200_gpio_shadow[2];
 
+unsigned scx200_cb_base = 0;
+
 static struct pci_device_id scx200_tbl[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_SCx200_BRIDGE) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_SC1100_BRIDGE) },
+	{ PCI_DEVICE(PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_SCx200_XBUS)   },
+	{ PCI_DEVICE(PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_SC1100_XBUS)   },
 	{ },
 };
 MODULE_DEVICE_TABLE(pci,scx200_tbl);
@@ -45,22 +52,39 @@ static int __devinit scx200_probe(struct pci_dev *pdev, const struct pci_device_
 	int bank;
 	unsigned base;
 
-	base = pci_resource_start(pdev, 0);
-	printk(KERN_INFO NAME ": GPIO base 0x%x\n", base);
-
-	if (request_region(base, SCx200_GPIO_SIZE, "NatSemi SCx200 GPIO") == 0) {
-		printk(KERN_ERR NAME ": can't allocate I/O for GPIOs\n");
-		return -EBUSY;
+	if (pdev->device == PCI_DEVICE_ID_NS_SCx200_BRIDGE ||
+	    pdev->device == PCI_DEVICE_ID_NS_SC1100_BRIDGE) {
+		base = pci_resource_start(pdev, 0);
+		printk(KERN_INFO NAME ": GPIO base 0x%x\n", base);
+
+		if (request_region(base, SCx200_GPIO_SIZE, "NatSemi SCx200 GPIO") == 0) {
+			printk(KERN_ERR NAME ": can't allocate I/O for GPIOs\n");
+			return -EBUSY;
+		}
+
+		scx200_gpio_base = base;
+
+		/* read the current values driven on the GPIO signals */
+		for (bank = 0; bank < 2; ++bank)
+			scx200_gpio_shadow[bank] = inl(scx200_gpio_base + 0x10 * bank);
+
+	} else {
+		/* find the base of the Configuration Block */
+		if (scx200_cb_probe(SCx200_CB_BASE_FIXED)) {
+			scx200_cb_base = SCx200_CB_BASE_FIXED;
+		} else {
+			pci_read_config_dword(pdev, SCx200_CBA_SCRATCH, &base);
+			if (scx200_cb_probe(base)) {
+				scx200_cb_base = base;
+			} else {
+				printk(KERN_WARNING NAME ": Configuration Block not found\n");
+				return -ENODEV;
+			}
+		}
+		printk(KERN_INFO NAME ": Configuration Block base 0x%x\n", scx200_cb_base);
 	}
 
-	scx200_gpio_base = base;
-
-	/* read the current values driven on the GPIO signals */
-	for (bank = 0; bank < 2; ++bank)
-		scx200_gpio_shadow[bank] = inl(scx200_gpio_base + 0x10 * bank);
-
 	return 0;
-
 }
 
 u32 scx200_gpio_configure(int index, u32 mask, u32 bits)
@@ -134,6 +158,7 @@ EXPORT_SYMBOL(scx200_gpio_shadow);
 EXPORT_SYMBOL(scx200_gpio_lock);
 EXPORT_SYMBOL(scx200_gpio_configure);
 EXPORT_SYMBOL(scx200_gpio_dump);
+EXPORT_SYMBOL(scx200_cb_base);
 
 /*
     Local variables:

drivers/char/watchdog/Kconfig

@@ -268,12 +268,12 @@ config SC1200_WDT
 
 config SCx200_WDT
 	tristate "National Semiconductor SCx200 Watchdog"
-	depends on WATCHDOG && X86 && PCI
+	depends on WATCHDOG && SCx200 && PCI
 	help
 	  Enable the built-in watchdog timer support on the National
 	  Semiconductor SCx200 processors.
 
-	  If compiled as a module, it will be called scx200_watchdog.
+	  If compiled as a module, it will be called scx200_wdt.
 
 config 60XX_WDT
 	tristate "SBC-60XX Watchdog Timer"

drivers/char/watchdog/scx200_wdt.c

@@ -4,7 +4,7 @@
 
    Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com>
 
-   Som code taken from:
+   Some code taken from:
    National Semiconductor PC87307/PC97307 (ala SC1200) WDT driver
    (c) Copyright 2002 Zwane Mwaikambo <zwane@commfireservices.com>
 
@@ -64,7 +64,7 @@ static char expect_close;
 
 static void scx200_wdt_ping(void)
 {
-	outw(wdto_restart, SCx200_CB_BASE + SCx200_WDT_WDTO);
+	outw(wdto_restart, scx200_cb_base + SCx200_WDT_WDTO);
 }
 
 static void scx200_wdt_update_margin(void)
@@ -78,9 +78,9 @@ static void scx200_wdt_enable(void)
 	printk(KERN_DEBUG NAME ": enabling watchdog timer, wdto_restart = %d\n",
 	       wdto_restart);
 
-	outw(0, SCx200_CB_BASE + SCx200_WDT_WDTO);
-	outb(SCx200_WDT_WDSTS_WDOVF, SCx200_CB_BASE + SCx200_WDT_WDSTS);
-	outw(W_ENABLE, SCx200_CB_BASE + SCx200_WDT_WDCNFG);
+	outw(0, scx200_cb_base + SCx200_WDT_WDTO);
+	outb(SCx200_WDT_WDSTS_WDOVF, scx200_cb_base + SCx200_WDT_WDSTS);
+	outw(W_ENABLE, scx200_cb_base + SCx200_WDT_WDCNFG);
 
 	scx200_wdt_ping();
 }
@@ -89,9 +89,9 @@ static void scx200_wdt_disable(void)
 {
 	printk(KERN_DEBUG NAME ": disabling watchdog timer\n");
 
-	outw(0, SCx200_CB_BASE + SCx200_WDT_WDTO);
-	outb(SCx200_WDT_WDSTS_WDOVF, SCx200_CB_BASE + SCx200_WDT_WDSTS);
-	outw(W_DISABLE, SCx200_CB_BASE + SCx200_WDT_WDCNFG);
+	outw(0, scx200_cb_base + SCx200_WDT_WDTO);
+	outb(SCx200_WDT_WDSTS_WDOVF, scx200_cb_base + SCx200_WDT_WDSTS);
+	outw(W_DISABLE, scx200_cb_base + SCx200_WDT_WDCNFG);
 }
 
 static int scx200_wdt_open(struct inode *inode, struct file *file)
@@ -217,28 +217,14 @@ static struct miscdevice scx200_wdt_miscdev = {
 static int __init scx200_wdt_init(void)
 {
 	int r;
-	static struct pci_device_id ns_sc[] = {
-		{ PCI_DEVICE(PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_SCx200_BRIDGE) },
-		{ PCI_DEVICE(PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_SC1100_BRIDGE) },
-		{ },
-	};
 
 	printk(KERN_DEBUG NAME ": NatSemi SCx200 Watchdog Driver\n");
 
-	/*
-	 * First check that this really is a NatSemi SCx200 CPU or a Geode
-	 * SC1100 processor
-	 */
-	if (!pci_dev_present(ns_sc))
-		return -ENODEV;
-
-	/* More sanity checks, verify that the configuration block is there */
-	if (!scx200_cb_probe(SCx200_CB_BASE)) {
-		printk(KERN_WARNING NAME ": no configuration block found\n");
+	/* check that we have found the configuration block */
+	if (!scx200_cb_present())
 		return -ENODEV;
-	}
 
-	if (!request_region(SCx200_CB_BASE + SCx200_WDT_OFFSET,
+	if (!request_region(scx200_cb_base + SCx200_WDT_OFFSET,
 			    SCx200_WDT_SIZE,
 			    "NatSemi SCx200 Watchdog")) {
 		printk(KERN_WARNING NAME ": watchdog I/O region busy\n");
@@ -252,7 +238,7 @@ static int __init scx200_wdt_init(void)
 
 	r = misc_register(&scx200_wdt_miscdev);
 	if (r) {
-		release_region(SCx200_CB_BASE + SCx200_WDT_OFFSET,
+		release_region(scx200_cb_base + SCx200_WDT_OFFSET,
 				SCx200_WDT_SIZE);
 		return r;
 	}
@@ -261,7 +247,7 @@ static int __init scx200_wdt_init(void)
 	if (r) {
 		printk(KERN_ERR NAME ": unable to register reboot notifier");
 		misc_deregister(&scx200_wdt_miscdev);
-		release_region(SCx200_CB_BASE + SCx200_WDT_OFFSET,
+		release_region(scx200_cb_base + SCx200_WDT_OFFSET,
 				SCx200_WDT_SIZE);
 		return r;
 	}
@@ -273,7 +259,7 @@ static void __exit scx200_wdt_cleanup(void)
 {
 	unregister_reboot_notifier(&scx200_wdt_notifier);
 	misc_deregister(&scx200_wdt_miscdev);
-	release_region(SCx200_CB_BASE + SCx200_WDT_OFFSET,
+	release_region(scx200_cb_base + SCx200_WDT_OFFSET,
 		       SCx200_WDT_SIZE);
 }
 

drivers/mtd/maps/Kconfig

@@ -159,7 +159,7 @@ config MTD_VMAX
 
 config MTD_SCx200_DOCFLASH
 	tristate "Flash device mapped with DOCCS on NatSemi SCx200"
-	depends on X86 && MTD_CFI && MTD_PARTITIONS
+	depends on SCx200 && MTD_CFI && MTD_PARTITIONS
 	help
 	  Enable support for a flash chip mapped using the DOCCS signal on a
 	  National Semiconductor SCx200 processor.

drivers/mtd/maps/scx200_docflash.c

@@ -92,17 +92,16 @@ static int __init init_scx200_docflash(void)
 				      PCI_DEVICE_ID_NS_SCx200_BRIDGE,
 				      NULL)) == NULL)
 		return -ENODEV;
-	
-	if (!scx200_cb_probe(SCx200_CB_BASE)) {
-		printk(KERN_WARNING NAME ": no configuration block found\n");
+
+	/* check that we have found the configuration block */
+	if (!scx200_cb_present())
 		return -ENODEV;
-	}
 
 	if (probe) {
 		/* Try to use the present flash mapping if any */
 		pci_read_config_dword(bridge, SCx200_DOCCS_BASE, &base);
 		pci_read_config_dword(bridge, SCx200_DOCCS_CTRL, &ctrl);
-		pmr = inl(SCx200_CB_BASE + SCx200_PMR);
+		pmr = inl(scx200_cb_base + SCx200_PMR);
 
 		if (base == 0
 		    || (ctrl & 0x07000000) != 0x07000000
@@ -155,14 +154,14 @@ static int __init init_scx200_docflash(void)
 		
 		pci_write_config_dword(bridge, SCx200_DOCCS_BASE, docmem.start);
 		pci_write_config_dword(bridge, SCx200_DOCCS_CTRL, ctrl);
-		pmr = inl(SCx200_CB_BASE + SCx200_PMR);
+		pmr = inl(scx200_cb_base + SCx200_PMR);
 		
 		if (width == 8) {
 			pmr &= ~(1<<6);
 		} else {
 			pmr |= (1<<6);
 		}
-		outl(pmr, SCx200_CB_BASE + SCx200_PMR);
+		outl(pmr, scx200_cb_base + SCx200_PMR);
 	}
 	
        	printk(KERN_INFO NAME ": DOCCS mapped at 0x%lx-0x%lx, width %d\n", 

include/linux/pci_ids.h

@@ -397,6 +397,8 @@
 #define PCI_DEVICE_ID_NS_SCx200_VIDEO	0x0504
 #define PCI_DEVICE_ID_NS_SCx200_XBUS	0x0505
 #define PCI_DEVICE_ID_NS_SC1100_BRIDGE	0x0510
+#define PCI_DEVICE_ID_NS_SC1100_SMI	0x0511
+#define PCI_DEVICE_ID_NS_SC1100_XBUS	0x0515
 #define PCI_DEVICE_ID_NS_87410		0xd001
 
 #define PCI_VENDOR_ID_TSENG		0x100c

include/linux/scx200.h

@@ -7,6 +7,10 @@
 
 /* Interesting stuff for the National Semiconductor SCx200 CPU */
 
+extern unsigned scx200_cb_base;
+
+#define scx200_cb_present() (scx200_cb_base!=0)
+
 /* F0 PCI Header/Bridge Configuration Registers */
 #define SCx200_DOCCS_BASE 0x78	/* DOCCS Base Address Register */
 #define SCx200_DOCCS_CTRL 0x7c	/* DOCCS Control Register */
@@ -15,7 +19,7 @@
 #define SCx200_GPIO_SIZE 0x2c	/* Size of GPIO register block */
 
 /* General Configuration Block */
-#define SCx200_CB_BASE 0x9000	/* Base fixed at 0x9000 according to errata */
+#define SCx200_CB_BASE_FIXED 0x9000	/* Base fixed at 0x9000 according to errata? */
 
 /* Watchdog Timer */
 #define SCx200_WDT_OFFSET 0x00	/* offset within configuration block */
@@ -44,9 +48,7 @@
 #define SCx200_IID 0x3c		/* IA On a Chip Identification Number Reg */
 #define SCx200_REV 0x3d		/* Revision Register */
 #define SCx200_CBA 0x3e		/* Configuration Base Address Register */
-
-/* Verify that the configuration block really is there */
-#define scx200_cb_probe(base) (inw((base) + SCx200_CBA) == (base))
+#define SCx200_CBA_SCRATCH 0x64	/* Configuration Base Address Scratchpad */
 
 /*
     Local variables: