[PATCH] Updated NatSemi SCx200 patches for Linux-2.5

This patch adds support for the National Semiconductor SCx200
processor family to Linux 2.5.

The patch consists of the following drivers:

  arch/i386/kernel/scx200.c -- give kernel access to the GPIO pins

  drivers/chars/scx200_gpio.c -- give userspace access to the GPIO pins
  drivers/chars/scx200_wdt.c -- watchdog timer driver

  drivers/i2c/scx200_i2c.c -- use any two GPIO pins as an I2C bus
  drivers/i2c/scx200_acb.c -- driver for the Access.BUS hardware

  drivers/mtd/maps/scx200_docflash.c -- driver for a CFI flash connected
                                      to the DOCCS pin

MAINTAINERS

@@ -1433,6 +1433,12 @@ M:	Kai.Makisara@metla.fi
 L:	linux-scsi@vger.kernel.org
 S:	Maintained
 
+SCx200 CPU SUPPORT
+P:	Christer Weinigel
+M:	christer@weinigel.se
+W:	http://www.weinigel.se
+S:	Supported
+
 SGI VISUAL WORKSTATION 320 AND 540
 P:	Bent Hagemark
 M:	bh@sgi.com

arch/i386/Config.help

@@ -1058,3 +1058,12 @@ CONFIG_SOFTWARE_SUSPEND
   absence of features.
 
   For more information take a look at Documentation/swsusp.txt.
+
+CONFIG_SCx200
+  This provides basic support for the National Semiconductor SCx200 
+  processor.  Right now this is just a driver for the GPIO pins.
+
+  If you don't know what to do here, say N.
+
+  This support is also available as a module.  If compiled as a
+  module, it will be called scx200.o.

arch/i386/config.in

@@ -293,6 +293,8 @@ else
    fi
 fi
 
+tristate 'NatSemi SCx200 support' CONFIG_SCx200
+
 source drivers/pci/Config.in
 
 bool 'EISA support' CONFIG_EISA

arch/i386/kernel/Makefile

@@ -29,4 +29,7 @@ obj-$(CONFIG_X86_NUMAQ)		+= numaq.o
 
 EXTRA_AFLAGS   := -traditional
 
+export-objs += scx200.o
+obj-$(CONFIG_SCx200)		+= scx200.o
+
 include $(TOPDIR)/Rules.make

arch/i386/kernel/scx200.c

+/* linux/arch/i386/kernel/scx200.c 
+
+   Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com>
+
+   National Semiconductor SCx200 support. */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+
+#include <linux/scx200.h>
+#include <linux/scx200.h>
+
+#define NAME "scx200"
+
+MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");
+MODULE_DESCRIPTION("NatSemi SCx200 Driver");
+MODULE_LICENSE("GPL");
+
+unsigned scx200_gpio_base = 0;
+long scx200_gpio_shadow[2];
+
+spinlock_t scx200_gpio_lock = SPIN_LOCK_UNLOCKED;
+static spinlock_t scx200_gpio_config_lock = SPIN_LOCK_UNLOCKED;
+
+u32 scx200_gpio_configure(int index, u32 mask, u32 bits)
+{
+	u32 config, new_config;
+	unsigned long flags;
+
+	spin_lock_irqsave(&scx200_gpio_config_lock, flags);
+
+	outl(index, scx200_gpio_base + 0x20);
+	config = inl(scx200_gpio_base + 0x24);
+
+	new_config = (config & mask) | bits;
+	outl(new_config, scx200_gpio_base + 0x24);
+
+	spin_unlock_irqrestore(&scx200_gpio_config_lock, flags);
+
+	return config;
+}
+
+void scx200_gpio_dump(unsigned index)
+{
+	u32 config = scx200_gpio_configure(index, ~0, 0);
+	printk(KERN_DEBUG "GPIO%02u: 0x%08lx", index, (unsigned long)config);
+	
+	if (config & 1) 
+		printk(" OE"); /* output enabled */
+	else
+		printk(" TS"); /* tristate */
+	if (config & 2) 
+		printk(" PP"); /* push pull */
+	else
+		printk(" OD"); /* open drain */
+	if (config & 4) 
+		printk(" PUE"); /* pull up enabled */
+	else
+		printk(" PUD"); /* pull up disabled */
+	if (config & 8) 
+		printk(" LOCKED"); /* locked */
+	if (config & 16) 
+		printk(" LEVEL"); /* level input */
+	else
+		printk(" EDGE"); /* edge input */
+	if (config & 32) 
+		printk(" HI"); /* trigger on rising edge */
+	else
+		printk(" LO"); /* trigger on falling edge */
+	if (config & 64) 
+		printk(" DEBOUNCE"); /* debounce */
+	printk("\n");
+}
+
+int __init scx200_init(void)
+{
+	struct pci_dev *bridge;
+	int bank;
+	unsigned base;
+
+	printk(KERN_INFO NAME ": NatSemi SCx200 Driver\n");
+
+	if ((bridge = pci_find_device(PCI_VENDOR_ID_NS, 
+				      PCI_DEVICE_ID_NS_SCx200_BRIDGE,
+				      NULL)) == NULL)
+		return -ENODEV;
+
+	base = pci_resource_start(bridge, 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);
+
+	return 0;
+}
+
+void __exit scx200_cleanup(void)
+{
+	release_region(scx200_gpio_base, SCx200_GPIO_SIZE);
+}
+
+module_init(scx200_init);
+module_exit(scx200_cleanup);
+
+EXPORT_SYMBOL(scx200_gpio_base);
+EXPORT_SYMBOL(scx200_gpio_shadow);
+EXPORT_SYMBOL(scx200_gpio_lock);
+EXPORT_SYMBOL(scx200_gpio_configure);
+EXPORT_SYMBOL(scx200_gpio_dump);
+
+/*
+    Local variables:
+        compile-command: "make -k -C ../../.. SUBDIRS=arch/i386/kernel modules"
+        c-basic-offset: 8
+    End:
+*/

drivers/char/Config.help

@@ -818,6 +818,12 @@ CONFIG_MIXCOMWD
   module, say M here and read <file:Documentation/modules.txt>.  Most
   people will say N.
 
+CONFIG_SCx200_WDT
+  Enable the built-in watchdog timer support on the National 
+  Semiconductor SCx200 processors.
+
+  If compiled as a module, it will be called scx200_watchdog.o.
+
 CONFIG_MACHZ_WDT
   If you are using a ZF Micro MachZ processor, say Y here, otherwise
   N.  This is the driver for the watchdog timer builtin on that
@@ -1021,3 +1027,9 @@ CONFIG_RAW_DRIVER
   Once bound, I/O against /dev/raw/rawN uses efficient zero-copy I/O. 
   See the raw(8) manpage for more details.
 
+CONFIG_SCx200_GPIO
+  Give userspace access to the GPIO pins on the National
+  Semiconductor SCx200 processors.
+
+  If compiled as a module, it will be called scx200_gpio.o.
+

drivers/char/Config.in

@@ -131,6 +131,7 @@ if [ "$CONFIG_WATCHDOG" != "n" ]; then
    tristate '  IB700 SBC Watchdog Timer' CONFIG_IB700_WDT
    tristate '  Intel i810 TCO timer / Watchdog' CONFIG_I810_TCO
    tristate '  Mixcom Watchdog' CONFIG_MIXCOMWD 
+   tristate '  NatSemi SCx200 Watchdog' CONFIG_SCx200_WDT
    tristate '  SBC-60XX Watchdog Timer' CONFIG_60XX_WDT
    tristate '  W83877F (EMACS) Watchdog Timer' CONFIG_W83877F_WDT
    tristate '  ZF MachZ Watchdog' CONFIG_MACHZ_WDT
@@ -193,6 +194,8 @@ if [ "$CONFIG_X86" = "y" ]; then
    tristate 'ACP Modem (Mwave) support' CONFIG_MWAVE
 fi
 
+dep_tristate 'NatSemi SCx200 GPIO Support' CONFIG_SCx200_GPIO $CONFIG_SCx200
+
 tristate '  RAW driver (/dev/raw/rawN)' CONFIG_RAW_DRIVER
 
 endmenu

drivers/char/Makefile

@@ -75,6 +75,7 @@ obj-$(CONFIG_PPDEV) += ppdev.o
 obj-$(CONFIG_DZ) += dz.o
 obj-$(CONFIG_NWBUTTON) += nwbutton.o
 obj-$(CONFIG_NWFLASH) += nwflash.o
+obj-$(CONFIG_SCx200_GPIO) += scx200_gpio.o
 
 # Only one watchdog can succeed. We probe the hardware watchdog
 # drivers first, then the softdog driver.  This means if your hardware
@@ -86,6 +87,7 @@ obj-$(CONFIG_ACQUIRE_WDT) += acquirewdt.o
 obj-$(CONFIG_ADVANTECH_WDT) += advantechwdt.o
 obj-$(CONFIG_IB700_WDT) += ib700wdt.o
 obj-$(CONFIG_MIXCOMWD) += mixcomwd.o
+obj-$(CONFIG_SCx200_WDT) += scx200_wdt.o
 obj-$(CONFIG_60XX_WDT) += sbc60xxwdt.o
 obj-$(CONFIG_WDT) += wdt.o
 obj-$(CONFIG_WDTPCI) += wdt_pci.o

drivers/char/scx200_gpio.c

+/* linux/drivers/char/scx200_gpio.c 
+
+   National Semiconductor SCx200 GPIO driver.  Allows a user space
+   process to play with the GPIO pins.
+
+   Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com> */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <asm/uaccess.h>
+#include <asm/io.h>
+
+#include <linux/scx200_gpio.h>
+
+#define NAME "scx200_gpio"
+
+MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");
+MODULE_DESCRIPTION("NatSemi SCx200 GPIO Pin Driver");
+MODULE_LICENSE("GPL");
+
+static int major = 0;		/* default to dynamic major */
+MODULE_PARM(major, "i");
+MODULE_PARM_DESC(major, "Major device number");
+
+static ssize_t scx200_gpio_write(struct file *file, const char *data, 
+				 size_t len, loff_t *ppos)
+{
+	unsigned m = minor(file->f_dentry->d_inode->i_rdev);
+	size_t i;
+
+	if (ppos != &file->f_pos)
+		return -ESPIPE;
+
+	for (i = 0; i < len; ++i) {
+		char c;
+		if (get_user(c, data+i))
+			return -EFAULT;
+		switch (c)
+		{
+		case '0': 
+			scx200_gpio_set(m, 0); 
+			break;
+		case '1': 
+			scx200_gpio_set(m, 1); 
+			break;
+		case 'O':
+			printk(KERN_INFO NAME ": GPIO%d output enabled\n", m);
+			scx200_gpio_configure(m, ~1, 1);
+			break;
+		case 'o':
+			printk(KERN_INFO NAME ": GPIO%d output disabled\n", m);
+			scx200_gpio_configure(m, ~1, 0);
+			break;
+		case 'T':
+			printk(KERN_INFO NAME ": GPIO%d output is push pull\n", m);
+			scx200_gpio_configure(m, ~2, 2);
+			break;
+		case 't':
+			printk(KERN_INFO NAME ": GPIO%d output is open drain\n", m);
+			scx200_gpio_configure(m, ~2, 0);
+			break;
+		case 'P':
+			printk(KERN_INFO NAME ": GPIO%d pull up enabled\n", m);
+			scx200_gpio_configure(m, ~4, 4);
+			break;
+		case 'p':
+			printk(KERN_INFO NAME ": GPIO%d pull up disabled\n", m);
+			scx200_gpio_configure(m, ~4, 0);
+			break;
+		}
+	}
+
+	return len;
+}
+
+static ssize_t scx200_gpio_read(struct file *file, char *buf,
+				size_t len, loff_t *ppos)
+{
+	unsigned m = minor(file->f_dentry->d_inode->i_rdev);
+	int value;
+
+	if (ppos != &file->f_pos)
+		return -ESPIPE;
+
+	value = scx200_gpio_get(m);
+	if (put_user(value ? '1' : '0', buf))
+		return -EFAULT;
+	
+	return 1;
+}
+
+static int scx200_gpio_open(struct inode *inode, struct file *file)
+{
+	unsigned m = minor(inode->i_rdev);
+	if (m > 63)
+		return -EINVAL;
+	return 0;
+}
+
+static int scx200_gpio_release(struct inode *inode, struct file *file)
+{
+	return 0;
+}
+
+
+static struct file_operations scx200_gpio_fops = {
+	.owner   = THIS_MODULE,
+	.write   = scx200_gpio_write,
+	.read    = scx200_gpio_read,
+	.open    = scx200_gpio_open,
+	.release = scx200_gpio_release,
+};
+
+static int __init scx200_gpio_init(void)
+{
+	int r;
+
+	printk(KERN_DEBUG NAME ": NatSemi SCx200 GPIO Driver\n");
+
+	if (!scx200_gpio_present()) {
+		printk(KERN_ERR NAME ": no SCx200 gpio pins available\n");
+		return -ENODEV;
+	}
+
+	r = register_chrdev(major, NAME, &scx200_gpio_fops);
+	if (r < 0) {
+		printk(KERN_ERR NAME ": unable to register character device\n");
+		return r;
+	}
+	if (!major) {
+		major = r;
+		printk(KERN_DEBUG NAME ": got dynamic major %d\n", major);
+	}
+
+	return 0;
+}
+
+static void __exit scx200_gpio_cleanup(void)
+{
+	unregister_chrdev(major, NAME);
+}
+
+module_init(scx200_gpio_init);
+module_exit(scx200_gpio_cleanup);
+
+/*
+    Local variables:
+        compile-command: "make -k -C ../.. SUBDIRS=drivers/char modules"
+        c-basic-offset: 8
+    End:
+*/

drivers/char/scx200_wdt.c

+/* linux/drivers/char/scx200_wdt.c 
+
+   National Semiconductor SCx200 Watchdog support
+
+   Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com>
+
+   Som code taken from:
+   National Semiconductor PC87307/PC97307 (ala SC1200) WDT driver
+   (c) Copyright 2002 Zwane Mwaikambo <zwane@commfireservices.com>
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The author(s) of this software shall not be held liable for damages
+   of any nature resulting due to the use of this software. This
+   software is provided AS-IS with no warranties. */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+#include <linux/pci.h>
+#include <asm/uaccess.h>
+#include <asm/io.h>
+
+#include <linux/scx200.h>
+
+#define NAME "scx200_wdt"
+
+MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");
+MODULE_DESCRIPTION("NatSemi SCx200 Watchdog Driver");
+MODULE_LICENSE("GPL");
+
+#ifndef CONFIG_WATCHDOG_NOWAYOUT
+#define CONFIG_WATCHDOG_NOWAYOUT 0
+#endif
+
+static int margin = 60;		/* in seconds */
+MODULE_PARM(margin, "i");
+MODULE_PARM_DESC(margin, "Watchdog margin in seconds");
+
+static int nowayout = CONFIG_WATCHDOG_NOWAYOUT;
+MODULE_PARM(nowayout, "i");
+MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");
+
+static u16 wdto_restart;
+static struct semaphore open_semaphore;
+static unsigned expect_close;
+
+/* Bits of the WDCNFG register */
+#define W_ENABLE 0x00fa		/* Enable watchdog */
+#define W_DISABLE 0x0000	/* Disable watchdog */
+
+/* The scaling factor for the timer, this depends on the value of W_ENABLE */
+#define W_SCALE (32768/1024)
+
+static void scx200_wdt_ping(void)
+{
+	outw(wdto_restart, SCx200_CB_BASE + SCx200_WDT_WDTO);
+}
+
+static void scx200_wdt_update_margin(void)
+{
+	printk(KERN_INFO NAME ": timer margin %d seconds\n", margin);
+	wdto_restart = margin * W_SCALE;
+}
+
+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);
+
+	scx200_wdt_ping();
+}
+
+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);
+}
+
+static int scx200_wdt_open(struct inode *inode, struct file *file)
+{
+        /* only allow one at a time */
+        if (down_trylock(&open_semaphore))
+                return -EBUSY;
+	scx200_wdt_enable();
+	expect_close = 0;
+
+	return 0;
+}
+
+static int scx200_wdt_release(struct inode *inode, struct file *file)
+{
+	if (!expect_close) {
+		printk(KERN_WARNING NAME ": watchdog device closed unexpectedly, will not disable the watchdog timer\n");
+	} else if (!nowayout) {
+		scx200_wdt_disable();
+	}
+        up(&open_semaphore);
+
+	return 0;
+}
+
+static int scx200_wdt_notify_sys(struct notifier_block *this, 
+				      unsigned long code, void *unused)
+{
+        if (code == SYS_HALT || code == SYS_POWER_OFF)
+		if (!nowayout)
+			scx200_wdt_disable();
+
+        return NOTIFY_DONE;
+}
+
+static struct notifier_block scx200_wdt_notifier =
+{
+        notifier_call: scx200_wdt_notify_sys
+};
+
+static ssize_t scx200_wdt_write(struct file *file, const char *data, 
+				     size_t len, loff_t *ppos)
+{
+	if (ppos != &file->f_pos)
+		return -ESPIPE;
+
+	/* check for a magic close character */
+	if (len) 
+	{
+		size_t i;
+
+		scx200_wdt_ping();
+
+		expect_close = 0;
+		for (i = 0; i < len; ++i) {
+			char c;
+			if (get_user(c, data+i))
+				return -EFAULT;
+			if (c == 'V')
+				expect_close = 1;
+		}
+
+		return len;
+	}
+
+	return 0;
+}
+
+static int scx200_wdt_ioctl(struct inode *inode, struct file *file,
+	unsigned int cmd, unsigned long arg)
+{
+	static struct watchdog_info ident = {
+		.identity = "NatSemi SCx200 Watchdog",
+		.firmware_version = 1, 
+		.options = (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING),
+	};
+	int new_margin;
+	
+	switch (cmd) {
+	default:
+		return -ENOTTY;
+	case WDIOC_GETSUPPORT:
+		if(copy_to_user((struct watchdog_info *)arg, &ident, 
+				sizeof(ident)))
+			return -EFAULT;
+		return 0;
+	case WDIOC_GETSTATUS:
+	case WDIOC_GETBOOTSTATUS:
+		if (put_user(0, (int *)arg))
+			return -EFAULT;
+		return 0;
+	case WDIOC_KEEPALIVE:
+		scx200_wdt_ping();
+		return 0;
+	case WDIOC_SETTIMEOUT:
+		if (get_user(new_margin, (int *)arg))
+			return -EFAULT;
+		if (new_margin < 1)
+			return -EINVAL;
+		margin = new_margin;
+		scx200_wdt_update_margin();
+		scx200_wdt_ping();
+	case WDIOC_GETTIMEOUT:
+		if (put_user(margin, (int *)arg))
+			return -EFAULT;
+		return 0;
+	}
+}
+
+static struct file_operations scx200_wdt_fops = {
+	.owner	 = THIS_MODULE,
+	.write   = scx200_wdt_write,
+	.ioctl   = scx200_wdt_ioctl,
+	.open    = scx200_wdt_open,
+	.release = scx200_wdt_release,
+};
+
+static struct miscdevice scx200_wdt_miscdev = {
+	.minor = WATCHDOG_MINOR,
+	.name  = NAME,
+	.fops  = &scx200_wdt_fops,
+};
+
+static int __init scx200_wdt_init(void)
+{
+	int r;
+
+	printk(KERN_DEBUG NAME ": NatSemi SCx200 Watchdog Driver\n");
+
+	/* First check that this really is a NatSemi SCx200 CPU */
+	if ((pci_find_device(PCI_VENDOR_ID_NS, 
+			     PCI_DEVICE_ID_NS_SCx200_BRIDGE,
+			     NULL)) == NULL)
+		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");
+		return -ENODEV;
+	}
+
+	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");
+		return -EBUSY;
+	}
+
+	scx200_wdt_update_margin();
+	scx200_wdt_disable();
+
+	sema_init(&open_semaphore, 1);
+
+	r = misc_register(&scx200_wdt_miscdev);
+	if (r)
+		return r;
+
+	r = register_reboot_notifier(&scx200_wdt_notifier);
+        if (r) {
+                printk(KERN_ERR NAME ": unable to register reboot notifier");
+		misc_deregister(&scx200_wdt_miscdev);
+                return r;
+        }
+
+	return 0;
+}
+
+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,
+		       SCx200_WDT_SIZE);
+}
+
+module_init(scx200_wdt_init);
+module_exit(scx200_wdt_cleanup);
+
+/*
+    Local variables:
+        compile-command: "make -k -C ../.. SUBDIRS=drivers/char modules"
+        c-basic-offset: 8
+    End:
+*/

drivers/i2c/Config.help

@@ -91,6 +91,28 @@ CONFIG_I2C_CHARDEV
   <file:Documentation/modules.txt>.
   The module will be called i2c-dev.o.
 
+CONFIG_SCx200_I2C
+  Enable the use of two GPIO pins of a SCx200 processor as an I2C bus.
+
+  If you don't know what to do here, say N.
+
+  If compiled as a module, it will be called scx200_i2c.o.
+
+CONFIG_SCx200_I2C_SCL
+  Enter the GPIO pin number used for the SCL signal.  This value can
+  also be specified with a module parameter.
+
+CONFIG_SCx200_I2C_SDA
+  Enter the GPIO pin number used for the SSA signal.  This value can
+  also be specified with a module parameter.
+
+CONFIG_SCx200_ACB
+  Enable the use of the ACCESS.bus controllers of a SCx200 processor.
+
+  If you don't know what to do here, say N.
+
+  If compiled as a module, it will be called scx200_acb.o.
+
 CONFIG_I2C_PROC
   This provides support for i2c device entries in the /proc filesystem.
   The entries will be found in /proc/sys/dev/sensors.

drivers/i2c/Config.in

@@ -13,6 +13,12 @@ if [ "$CONFIG_I2C" != "n" ]; then
       dep_tristate '  Philips style parallel port adapter' CONFIG_I2C_PHILIPSPAR $CONFIG_I2C_ALGOBIT $CONFIG_PARPORT
       dep_tristate '  ELV adapter' CONFIG_I2C_ELV $CONFIG_I2C_ALGOBIT
       dep_tristate '  Velleman K9000 adapter' CONFIG_I2C_VELLEMAN $CONFIG_I2C_ALGOBIT
+      dep_tristate '  NatSemi SCx200 I2C using GPIO pins' CONFIG_SCx200_I2C $CONFIG_SCx200 $CONFIG_I2C_ALGOBIT
+      if [ "$CONFIG_SCx200_I2C" != "n" ]; then
+         int  '    GPIO pin used for SCL' CONFIG_SCx200_I2C_SCL 12
+         int  '    GPIO pin used for SDA' CONFIG_SCx200_I2C_SDA 13
+      fi
+      dep_tristate '  NatSemi SCx200 ACCESS.bus' CONFIG_SCx200_ACB $CONFIG_I2C
    fi
 
    dep_tristate 'I2C PCF 8584 interfaces' CONFIG_I2C_ALGOPCF $CONFIG_I2C

drivers/i2c/Makefile

@@ -15,6 +15,8 @@ obj-$(CONFIG_I2C_ALGOPCF)	+= i2c-algo-pcf.o
 obj-$(CONFIG_I2C_ELEKTOR)	+= i2c-elektor.o
 obj-$(CONFIG_ITE_I2C_ALGO)	+= i2c-algo-ite.o
 obj-$(CONFIG_ITE_I2C_ADAP)	+= i2c-adap-ite.o
+obj-$(CONFIG_SCx200_I2C)	+= scx200_i2c.o
+obj-$(CONFIG_SCx200_ACB)	+= scx200_acb.o
 obj-$(CONFIG_I2C_PROC)		+= i2c-proc.o
 
 # This is needed for automatic patch generation: sensors code starts here

drivers/i2c/scx200_acb.c

+/*  linux/drivers/i2c/scx200_acb.c 
+
+    Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com>
+
+    National Semiconductor SCx200 ACCESS.bus support
+    
+    Based on i2c-keywest.c which is:
+        Copyright (c) 2001 Benjamin Herrenschmidt <benh@kernel.crashing.org>
+        Copyright (c) 2000 Philip Edelbrock <phil@stimpy.netroedge.com>
+    
+    This program is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License as
+    published by the Free Software Foundation; either version 2 of the
+    License, or (at your option) any later version.
+   
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    General Public License for more details.
+   
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+#include <linux/smp_lock.h>
+#include <linux/pci.h>
+#include <asm/io.h>
+
+#include <linux/scx200.h>
+
+#define NAME "scx200_acb"
+
+MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");
+MODULE_DESCRIPTION("NatSemi SCx200 ACCESS.bus Driver");
+MODULE_LICENSE("GPL");
+
+#define MAX_DEVICES 4
+static int base[MAX_DEVICES] = { 0x840 };
+MODULE_PARM(base, "1-4i");
+MODULE_PARM_DESC(base, "Base addresses for the ACCESS.bus controllers");
+
+#define DEBUG 0
+
+#if DEBUG
+#define DBG(x...) printk(KERN_DEBUG NAME ": " x)
+#else
+#define DBG(x...)
+#endif
+
+/* The hardware supports interrupt driven mode too, but I haven't
+   implemented that. */
+#define POLLED_MODE 1
+#define POLL_TIMEOUT (HZ)
+
+enum scx200_acb_state {
+	state_idle,
+	state_address,
+	state_command,
+	state_repeat_start,
+	state_quick,
+	state_read,
+	state_write,
+};
+
+static const char *scx200_acb_state_name[] = {
+	"idle",
+	"address",
+	"command",
+	"repeat_start",
+	"quick",
+	"read",
+	"write",
+};
+
+/* Physical interface */
+struct scx200_acb_iface
+{
+	struct scx200_acb_iface *next;
+	struct i2c_adapter adapter;
+	unsigned base;
+	struct semaphore sem;
+
+	/* State machine data */
+	enum scx200_acb_state state;
+	int result;
+	u8 address_byte;
+	u8 command;
+	u8 *ptr;
+	char needs_reset;
+	unsigned len;
+};
+
+/* Register Definitions */
+#define ACBSDA		(iface->base + 0)
+#define ACBST		(iface->base + 1)
+#define    ACBST_SDAST		0x40 /* SDA Status */
+#define    ACBST_BER		0x20 
+#define    ACBST_NEGACK		0x10 /* Negative Acknowledge */
+#define    ACBST_STASTR		0x08 /* Stall After Start */
+#define    ACBST_MASTER		0x02
+#define ACBCST		(iface->base + 2)
+#define    ACBCST_BB		0x02
+#define ACBCTL1		(iface->base + 3)
+#define    ACBCTL1_STASTRE	0x80
+#define    ACBCTL1_NMINTE	0x40
+#define	   ACBCTL1_ACK		0x10
+#define	   ACBCTL1_STOP		0x02
+#define	   ACBCTL1_START	0x01
+#define ACBADDR		(iface->base + 4)
+#define ACBCTL2		(iface->base + 5)
+#define    ACBCTL2_ENABLE	0x01
+
+/************************************************************************/
+
+static void scx200_acb_machine(struct scx200_acb_iface *iface, u8 status)
+{
+	const char *errmsg;
+
+	DBG("state %s, status = 0x%02x\n", 
+	    scx200_acb_state_name[iface->state], status);
+
+	if (status & ACBST_BER) {
+		errmsg = "bus error";
+		goto error;
+	}
+	if (!(status & ACBST_MASTER)) {
+		errmsg = "not master";
+		goto error;
+	}
+	if (status & ACBST_NEGACK)
+		goto negack;
+
+	switch (iface->state) {
+	case state_idle:
+		printk(KERN_WARNING NAME ": %s, interrupt in idle state\n", 
+		       iface->adapter.name);
+		break;
+
+	case state_address:
+		/* Do a pointer write first */
+		outb(iface->address_byte & ~1, ACBSDA);
+
+		iface->state = state_command;
+		break;
+
+	case state_command:
+		outb(iface->command, ACBSDA);
+
+		if (iface->address_byte & 1)
+			iface->state = state_repeat_start;
+		else
+			iface->state = state_write;
+		break;
+
+	case state_repeat_start:
+		outb(inb(ACBCTL1) | ACBCTL1_START, ACBCTL1);
+		/* fallthrough */
+		
+	case state_quick:
+		if (iface->address_byte & 1) {
+			if (iface->len == 1) 
+				outb(inb(ACBCTL1) | ACBCTL1_ACK, ACBCTL1);
+			else
+				outb(inb(ACBCTL1) & ~ACBCTL1_ACK, ACBCTL1);
+			outb(iface->address_byte, ACBSDA);
+
+			iface->state = state_read;
+		} else {
+			outb(iface->address_byte, ACBSDA);
+
+			iface->state = state_write;
+		}
+		break;
+
+	case state_read:
+		/* Set ACK if receiving the last byte */
+		if (iface->len == 1)
+			outb(inb(ACBCTL1) | ACBCTL1_ACK, ACBCTL1);
+		else
+			outb(inb(ACBCTL1) & ~ACBCTL1_ACK, ACBCTL1);
+
+		*iface->ptr++ = inb(ACBSDA);
+		--iface->len;
+
+		if (iface->len == 0) {
+			iface->result = 0;
+			iface->state = state_idle;
+			outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
+		}
+
+		break;
+
+	case state_write:
+		if (iface->len == 0) {
+			iface->result = 0;
+			iface->state = state_idle;
+			outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
+			break;
+		}
+		
+		outb(*iface->ptr++, ACBSDA);
+		--iface->len;
+		
+		break;
+	}
+
+	return;
+
+ negack:
+	DBG("negative acknowledge in state %s\n", 
+	    scx200_acb_state_name[iface->state]);
+
+	iface->state = state_idle;
+	iface->result = -ENXIO;
+
+	outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
+	outb(ACBST_STASTR | ACBST_NEGACK, ACBST);
+	return;
+
+ error:
+	printk(KERN_ERR NAME ": %s, %s in state %s\n", iface->adapter.name, 
+	       errmsg, scx200_acb_state_name[iface->state]);
+
+	iface->state = state_idle;
+	iface->result = -EIO;
+	iface->needs_reset = 1;
+}
+
+static void scx200_acb_timeout(struct scx200_acb_iface *iface) 
+{
+	printk(KERN_ERR NAME ": %s, timeout in state %s\n", 
+	       iface->adapter.name, scx200_acb_state_name[iface->state]);
+
+	iface->state = state_idle;
+	iface->result = -EIO;
+	iface->needs_reset = 1;
+}
+
+#ifdef POLLED_MODE
+static void scx200_acb_poll(struct scx200_acb_iface *iface)
+{
+	u8 status = 0;
+	unsigned long timeout;
+
+	timeout = jiffies + POLL_TIMEOUT;
+	while (time_before(jiffies, timeout)) {
+		status = inb(ACBST);
+		if ((status & (ACBST_SDAST|ACBST_BER|ACBST_NEGACK)) != 0) {
+			scx200_acb_machine(iface, status);
+			return;
+		}
+		schedule_timeout(HZ/100+1);
+	}
+
+	scx200_acb_timeout(iface);
+}
+#endif /* POLLED_MODE */
+
+static void scx200_acb_reset(struct scx200_acb_iface *iface)
+{
+	/* Disable the ACCESS.bus device and Configure the SCL
+           frequency: 16 clock cycles */
+	outb(0x70, ACBCTL2);
+	/* Polling mode */
+	outb(0, ACBCTL1);
+	/* Disable slave address */
+	outb(0, ACBADDR);
+	/* Enable the ACCESS.bus device */
+	outb(inb(ACBCTL2) | ACBCTL2_ENABLE, ACBCTL2);
+	/* Free STALL after START */
+	outb(inb(ACBCTL1) & ~(ACBCTL1_STASTRE | ACBCTL1_NMINTE), ACBCTL1);
+	/* Send a STOP */
+	outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
+	/* Clear BER, NEGACK and STASTR bits */
+	outb(ACBST_BER | ACBST_NEGACK | ACBST_STASTR, ACBST);
+	/* Clear BB bit */
+	outb(inb(ACBCST) | ACBCST_BB, ACBCST);
+}
+
+static s32 scx200_acb_smbus_xfer(struct i2c_adapter *adapter,
+				u16 address, unsigned short flags,	
+				char rw, u8 command, int size, 
+				union i2c_smbus_data *data)
+{
+	struct scx200_acb_iface *iface = adapter->data;
+	int len;
+	u8 *buffer;
+	u16 cur_word;
+	int rc;
+
+	switch (size) {
+	case I2C_SMBUS_QUICK:
+	    	len = 0;
+	    	buffer = NULL;
+	    	break;
+	case I2C_SMBUS_BYTE:
+		if (rw == I2C_SMBUS_READ) {
+			len = 1;
+			buffer = &data->byte;
+		} else {
+			len = 1;
+			buffer = &command;
+		}
+	    	break;
+	case I2C_SMBUS_BYTE_DATA:
+	    	len = 1;
+	    	buffer = &data->byte;
+	    	break;
+	case I2C_SMBUS_WORD_DATA:
+		len = 2;
+	    	cur_word = cpu_to_le16(data->word);
+	    	buffer = (u8 *)&cur_word;
+		break;
+	case I2C_SMBUS_BLOCK_DATA:
+	    	len = data->block[0];
+	    	buffer = &data->block[1];
+		break;
+	default:
+	    	return -EINVAL;
+	}
+
+	DBG("size=%d, address=0x%x, command=0x%x, len=%d, read=%d\n",
+	    size, address, command, len, rw == I2C_SMBUS_READ);
+
+	if (!len && rw == I2C_SMBUS_READ) {
+		printk(KERN_WARNING NAME ": %s, zero length read\n", 
+		       adapter->name);
+		return -EINVAL;
+	}
+
+	if (len && !buffer) {
+		printk(KERN_WARNING NAME ": %s, nonzero length but no buffer\n", adapter->name);
+		return -EFAULT;
+	}
+
+	down(&iface->sem);
+
+	iface->address_byte = address<<1;
+	if (rw == I2C_SMBUS_READ)
+		iface->address_byte |= 1;
+	iface->command = command;
+	iface->ptr = buffer;
+	iface->len = len;
+	iface->result = -EINVAL;
+	iface->needs_reset = 0;
+
+	outb(inb(ACBCTL1) | ACBCTL1_START, ACBCTL1);
+
+	if (size == I2C_SMBUS_QUICK || size == I2C_SMBUS_BYTE)
+		iface->state = state_quick;
+	else
+		iface->state = state_address;
+
+#ifdef POLLED_MODE
+	while (iface->state != state_idle)
+		scx200_acb_poll(iface);
+#else /* POLLED_MODE */
+#error Interrupt driven mode not implemented
+#endif /* POLLED_MODE */	
+
+	if (iface->needs_reset)
+		scx200_acb_reset(iface);
+
+	rc = iface->result;
+
+	up(&iface->sem);
+
+	if (rc == 0 && size == I2C_SMBUS_WORD_DATA && rw == I2C_SMBUS_READ)
+	    	data->word = le16_to_cpu(cur_word);
+
+#if DEBUG
+	printk(KERN_DEBUG NAME ": transfer done, result: %d", rc);
+	if (buffer) {
+		int i;
+		printk(" data:");
+		for (i = 0; i < len; ++i)
+			printk(" %02x", buffer[i]);
+	}
+	printk("\n");
+#endif
+
+	return rc;
+}
+
+static u32 scx200_acb_func(struct i2c_adapter *adapter)
+{
+	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
+	       I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
+	       I2C_FUNC_SMBUS_BLOCK_DATA;
+}
+
+static int scx200_acb_reg(struct i2c_client *client)
+{
+	return 0;
+}
+
+static int scx200_acb_unreg(struct i2c_client *client)
+{
+	return 0;
+}
+
+static void scx200_acb_inc_use(struct i2c_adapter *adapter)
+{
+	MOD_INC_USE_COUNT;
+}
+
+static void scx200_acb_dec_use(struct i2c_adapter *adapter)
+{
+	MOD_DEC_USE_COUNT;
+}
+
+/* For now, we only handle combined mode (smbus) */
+static struct i2c_algorithm scx200_acb_algorithm = {
+	name:		"NatSemi SCx200 ACCESS.bus",
+	id:		I2C_ALGO_SMBUS,
+	smbus_xfer:	scx200_acb_smbus_xfer,
+	functionality:	scx200_acb_func,
+};
+
+struct scx200_acb_iface *scx200_acb_list;
+
+int scx200_acb_probe(struct scx200_acb_iface *iface)
+{
+	u8 val;
+
+	/* Disable the ACCESS.bus device and Configure the SCL
+           frequency: 16 clock cycles */
+	outb(0x70, ACBCTL2);
+
+	if (inb(ACBCTL2) != 0x70) {
+		DBG("ACBCTL2 readback failed\n");
+		return -ENXIO;
+	}
+
+	outb(inb(ACBCTL1) | ACBCTL1_NMINTE, ACBCTL1);
+
+	val = inb(ACBCTL1);
+	if (val) {
+		DBG("disabled, but ACBCTL1=0x%02x\n", val);
+		return -ENXIO;
+	}
+
+	outb(inb(ACBCTL2) | ACBCTL2_ENABLE, ACBCTL2);
+
+	outb(inb(ACBCTL1) | ACBCTL1_NMINTE, ACBCTL1);
+
+	val = inb(ACBCTL1);
+	if ((val & ACBCTL1_NMINTE) != ACBCTL1_NMINTE) {
+		DBG("enabled, but NMINTE won't be set, ACBCTL1=0x%02x\n", val);
+		return -ENXIO;
+	}
+
+	return 0;
+}
+
+static int  __init scx200_acb_create(int base, int index)
+{
+	struct scx200_acb_iface *iface;
+	struct i2c_adapter *adapter;
+	int rc = 0;
+	char description[64];
+
+	iface = kmalloc(sizeof(*iface), GFP_KERNEL);
+	if (!iface) {
+		printk(KERN_ERR NAME ": can't allocate memory\n");
+		rc = -ENOMEM;
+		goto errout;
+	}
+
+	memset(iface, 0, sizeof(*iface));
+	adapter = &iface->adapter;
+	adapter->data = iface;
+	sprintf(adapter->name, "SCx200 ACB%d", index);
+	adapter->id = I2C_ALGO_SMBUS;
+	adapter->algo = &scx200_acb_algorithm;
+	adapter->inc_use = scx200_acb_inc_use;
+	adapter->dec_use = scx200_acb_dec_use;
+	adapter->client_register = scx200_acb_reg;
+	adapter->client_unregister = scx200_acb_unreg;
+
+	init_MUTEX(&iface->sem);
+
+	sprintf(description, "NatSemi SCx200 ACCESS.bus [%s]", adapter->name);
+	if (request_region(base, 8, description) == 0) {
+		printk(KERN_ERR NAME ": %s, can't allocate io 0x%x-0x%x\n", 
+		       adapter->name, base, base + 8-1);
+		rc = -EBUSY;
+		goto errout;
+	}
+	iface->base = base;
+
+	rc = scx200_acb_probe(iface);
+	if (rc) {
+		printk(KERN_WARNING NAME ": %s, probe failed\n", adapter->name);
+		goto errout;
+	}
+
+	scx200_acb_reset(iface);
+
+	if (i2c_add_adapter(adapter) < 0) {
+		printk(KERN_ERR NAME ": %s, failed to register\n", adapter->name);
+		rc = -ENODEV;
+		goto errout;
+	}
+
+	lock_kernel();
+	iface->next = scx200_acb_list;
+	scx200_acb_list = iface;
+	unlock_kernel();
+
+	return 0;
+
+ errout:
+	if (iface) {
+		if (iface->base)
+			release_region(iface->base, 8);
+		kfree(iface);
+	}
+	return rc;
+}
+
+static int __init scx200_acb_init(void)
+{
+	int i;
+	int rc;
+
+	printk(KERN_DEBUG NAME ": NatSemi SCx200 ACCESS.bus Driver\n");
+
+	/* Verify that this really is a SCx200 processor */
+	if (pci_find_device(PCI_VENDOR_ID_NS,
+			    PCI_DEVICE_ID_NS_SCx200_BRIDGE,
+			    NULL) == NULL)
+		return -ENODEV;
+
+	rc = -ENXIO;
+	for (i = 0; i < MAX_DEVICES; ++i) {
+		if (base[i] > 0)
+			rc = scx200_acb_create(base[i], i);
+	}
+	if (scx200_acb_list)
+		return 0;
+	return rc;
+}
+
+static void __exit scx200_acb_cleanup(void)
+{
+	struct scx200_acb_iface *iface;
+	lock_kernel();
+	while ((iface = scx200_acb_list) != NULL) {
+		scx200_acb_list = iface->next;
+		unlock_kernel();
+
+		i2c_del_adapter(&iface->adapter);
+		release_region(iface->base, 8);
+		kfree(iface);
+		lock_kernel();
+	}
+	unlock_kernel();
+}
+
+module_init(scx200_acb_init);
+module_exit(scx200_acb_cleanup);
+
+/*
+    Local variables:
+        compile-command: "make -k -C ../.. SUBDIRS=drivers/i2c modules"
+        c-basic-offset: 8
+    End:
+*/
+

drivers/i2c/scx200_i2c.c

+/* linux/drivers/i2c/scx200_i2c.c 
+
+   Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com>
+
+   National Semiconductor SCx200 I2C bus on GPIO pins
+
+   Based on i2c-velleman.c Copyright (C) 1995-96, 2000 Simon G. Vogl
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+   
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.		     
+*/
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+#include <linux/i2c-algo-bit.h>
+#include <asm/io.h>
+
+#include <linux/scx200_gpio.h>
+
+#define NAME "scx200_i2c"
+
+MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");
+MODULE_DESCRIPTION("NatSemi SCx200 I2C Driver");
+MODULE_LICENSE("GPL");
+
+MODULE_PARM(scl, "i");
+MODULE_PARM_DESC(scl, "GPIO line for SCL");
+MODULE_PARM(sda, "i");
+MODULE_PARM_DESC(sda, "GPIO line for SDA");
+
+static int scl = CONFIG_SCx200_I2C_SCL;
+static int sda = CONFIG_SCx200_I2C_SDA;
+
+static void scx200_i2c_setscl(void *data, int state)
+{
+	scx200_gpio_set(scl, state);
+}
+
+static void scx200_i2c_setsda(void *data, int state)
+{
+	scx200_gpio_set(sda, state);
+} 
+
+static int scx200_i2c_getscl(void *data)
+{
+	return scx200_gpio_get(scl);
+}
+
+static int scx200_i2c_getsda(void *data)
+{
+	return scx200_gpio_get(sda);
+}
+
+static int scx200_i2c_reg(struct i2c_client *client)
+{
+	return 0;
+}
+
+static int scx200_i2c_unreg(struct i2c_client *client)
+{
+	return 0;
+}
+
+static void scx200_i2c_inc_use(struct i2c_adapter *adap)
+{
+	MOD_INC_USE_COUNT;
+}
+
+static void scx200_i2c_dec_use(struct i2c_adapter *adap)
+{
+	MOD_DEC_USE_COUNT;
+}
+
+/* ------------------------------------------------------------------------
+ * Encapsulate the above functions in the correct operations structure.
+ * This is only done when more than one hardware adapter is supported.
+ */
+
+static struct i2c_algo_bit_data scx200_i2c_data = {
+	NULL,
+	scx200_i2c_setsda,
+	scx200_i2c_setscl,
+	scx200_i2c_getsda,
+	scx200_i2c_getscl,
+	10, 10, 100,		/* waits, timeout */
+};
+
+static struct i2c_adapter scx200_i2c_ops = {
+	.name              = "NatSemi SCx200 I2C",
+	.id		   = I2C_HW_B_VELLE,
+	.algo_data	   = &scx200_i2c_data,
+	.inc_use	   = scx200_i2c_inc_use,
+	.dec_use	   = scx200_i2c_dec_use,
+	.client_register   = scx200_i2c_reg,
+	.client_unregister = scx200_i2c_unreg,
+};
+
+int scx200_i2c_init(void)
+{
+	printk(KERN_DEBUG NAME ": NatSemi SCx200 I2C Driver\n");
+
+	if (!scx200_gpio_present()) {
+		printk(KERN_ERR NAME ": no SCx200 gpio pins available\n");
+		return -ENODEV;
+	}
+
+	printk(KERN_DEBUG NAME ": SCL=GPIO%02u, SDA=GPIO%02u\n", 
+	       scl, sda);
+
+	if (scl == -1 || sda == -1 || scl == sda) {
+		printk(KERN_ERR NAME ": scl and sda must be specified\n");
+		return -EINVAL;
+	}
+
+	/* Configure GPIOs as open collector outputs */
+	scx200_gpio_configure(scl, ~2, 5);
+	scx200_gpio_configure(sda, ~2, 5);
+
+	if (i2c_bit_add_bus(&scx200_i2c_ops) < 0) {
+		printk(KERN_ERR NAME ": adapter %s registration failed\n", 
+		       scx200_i2c_ops.name);
+		return -ENODEV;
+	}
+	
+	return 0;
+}
+
+void scx200_i2c_cleanup(void)
+{
+	i2c_bit_del_bus(&scx200_i2c_ops);
+}
+
+module_init(scx200_i2c_init);
+module_exit(scx200_i2c_cleanup);
+
+/*
+    Local variables:
+        compile-command: "make -k -C ../.. SUBDIRS=drivers/i2c modules"
+        c-basic-offset: 8
+    End:
+*/

drivers/mtd/maps/Config.help

@@ -127,6 +127,14 @@ CONFIG_MTD_MIXMEM
   you probably want to enable this mapping driver. More info is at
   <http://www.itc.hu/>.
 
+CONFIG_MTD_SCx200_DOCFLASH
+  Enable support for a flash chip mapped using the DOCCS signal on a
+  National Semiconductor SCx200 processor.
+
+  If you don't know what to do here, say N.
+
+  If compiled as a module, it will be called scx200_docflash.o.
+
 CONFIG_MTD_OCTAGON
   This provides a 'mapping' driver which supports the way in which
   the flash chips are connected in the Octagon-5066 Single Board

drivers/mtd/maps/Config.in

@@ -26,6 +26,7 @@ if [ "$CONFIG_X86" = "y" ]; then
    dep_tristate '  JEDEC Flash device mapped on Mixcom piggyback card' CONFIG_MTD_MIXMEM $CONFIG_MTD_JEDEC
    dep_tristate '  JEDEC Flash device mapped on Octagon 5066 SBC' CONFIG_MTD_OCTAGON $CONFIG_MTD_JEDEC
    dep_tristate '  JEDEC Flash device mapped on Tempustech VMAX SBC301' CONFIG_MTD_VMAX $CONFIG_MTD_JEDEC
+   dep_tristate '  Flash device mapped with DOCCS on NatSemi SCx200' CONFIG_MTD_SCx200_DOCFLASH $CONFIG_MTD_CFI
    dep_tristate '  BIOS flash chip on Intel L440GX boards' CONFIG_MTD_L440GX $CONFIG_MTD_JEDEC
 fi
 

drivers/mtd/maps/Makefile

@@ -24,6 +24,7 @@ obj-$(CONFIG_MTD_SC520CDP)	+= sc520cdp.o
 obj-$(CONFIG_MTD_NETSC520)	+= netsc520.o
 obj-$(CONFIG_MTD_SUN_UFLASH)    += sun_uflash.o
 obj-$(CONFIG_MTD_VMAX)		+= vmax301.o
+obj-$(CONFIG_MTD_SCx200_DOCFLASH)+= scx200_docflash.o
 obj-$(CONFIG_MTD_DBOX2)		+= dbox2-flash.o
 obj-$(CONFIG_MTD_OCELOT)	+= ocelot.o
 obj-$(CONFIG_MTD_SOLUTIONENGINE)+= solutionengine.o

drivers/mtd/maps/scx200_docflash.c

+/* linux/drivers/mtd/maps/scx200_docflash.c 
+
+   Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com>
+
+   National Semiconductor SCx200 flash mapped with DOCCS
+*/
+
+#include <linux/module.h>
+#include <linux/config.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <asm/io.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/map.h>
+#include <linux/mtd/partitions.h>
+
+#include <linux/pci.h>
+#include <linux/scx200.h>
+
+#define NAME "scx200_docflash"
+
+MODULE_AUTHOR("Christer Weinigel <wingel@hack.org>");
+MODULE_DESCRIPTION("NatSemi SCx200 DOCCS Flash Driver");
+MODULE_LICENSE("GPL");
+
+/* Set this to one if you want to partition the flash */
+#define PARTITION 1
+
+MODULE_PARM(probe, "i");
+MODULE_PARM_DESC(probe, "Probe for a BIOS mapping");
+MODULE_PARM(size, "i");
+MODULE_PARM_DESC(size, "Size of the flash mapping");
+MODULE_PARM(width, "i");
+MODULE_PARM_DESC(width, "Data width of the flash mapping (8/16)");
+MODULE_PARM(flashtype, "s");
+MODULE_PARM_DESC(flashtype, "Type of MTD probe to do");
+
+static int probe = 0;		/* Don't autoprobe */
+static unsigned size = 0x1000000; /* 16 MB the whole ISA address space */
+static unsigned width = 8;	/* Default to 8 bits wide */
+static char *flashtype = "cfi_probe";
+
+static struct resource docmem = {
+	.flags = IORESOURCE_MEM,
+	.name  = "NatSemi SCx200 DOCCS Flash",
+};
+
+static struct mtd_info *mymtd;
+
+#if PARTITION
+static struct mtd_partition partition_info[] = {
+	{ 
+		.name   = "DOCCS Boot kernel", 
+		.offset = 0, 
+		.size   = 0xc0000
+	},
+	{ 
+		.name   = "DOCCS Low BIOS", 
+		.offset = 0xc0000, 
+		.size   = 0x40000
+	},
+	{ 
+		.name   = "DOCCS File system", 
+		.offset = 0x100000, 
+		.size   = ~0	/* calculate from flash size */
+	},
+	{ 
+		.name   = "DOCCS High BIOS", 
+		.offset = ~0, 	/* calculate from flash size */
+		.size   = 0x80000
+	},
+};
+#define NUM_PARTITIONS (sizeof(partition_info)/sizeof(partition_info[0]))
+#endif
+
+static __u8 scx200_docflash_read8(struct map_info *map, unsigned long ofs)
+{
+	return __raw_readb(map->map_priv_1 + ofs);
+}
+
+static __u16 scx200_docflash_read16(struct map_info *map, unsigned long ofs)
+{
+	return __raw_readw(map->map_priv_1 + ofs);
+}
+
+static void scx200_docflash_copy_from(struct map_info *map, void *to, unsigned long from, ssize_t len)
+{
+	memcpy_fromio(to, map->map_priv_1 + from, len);
+}
+
+static void scx200_docflash_write8(struct map_info *map, __u8 d, unsigned long adr)
+{
+	__raw_writeb(d, map->map_priv_1 + adr);
+	mb();
+}
+
+static void scx200_docflash_write16(struct map_info *map, __u16 d, unsigned long adr)
+{
+	__raw_writew(d, map->map_priv_1 + adr);
+	mb();
+}
+
+static void scx200_docflash_copy_to(struct map_info *map, unsigned long to, const void *from, ssize_t len)
+{
+	memcpy_toio(map->map_priv_1 + to, from, len);
+}
+
+static struct map_info scx200_docflash_map = {
+	.name      = "NatSemi SCx200 DOCCS Flash",
+	.read8     = scx200_docflash_read8,
+	.read16    = scx200_docflash_read16,
+	.copy_from = scx200_docflash_copy_from,
+	.write8    = scx200_docflash_write8,
+	.write16   = scx200_docflash_write16,
+	.copy_to   = scx200_docflash_copy_to
+};
+
+int __init init_scx200_docflash(void)
+{
+	unsigned u;
+	unsigned base;
+	unsigned ctrl;
+	unsigned pmr;
+	struct pci_dev *bridge;
+
+	printk(KERN_DEBUG NAME ": NatSemi SCx200 DOCCS Flash Driver\n");
+
+	if ((bridge = pci_find_device(PCI_VENDOR_ID_NS, 
+				      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");
+		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);
+
+		if (base == 0
+		    || (ctrl & 0x07000000) != 0x07000000
+		    || (ctrl & 0x0007ffff) == 0)
+			return -ENODEV;
+
+		size = ((ctrl&0x1fff)<<13) + (1<<13);
+
+		for (u = size; u > 1; u >>= 1)
+			;
+		if (u != 1)
+			return -ENODEV;
+
+		if (pmr & (1<<6))
+			width = 16;
+		else
+			width = 8;
+
+		docmem.start = base;
+		docmem.end = base + size;
+
+		if (request_resource(&iomem_resource, &docmem)) {
+			printk(KERN_ERR NAME ": unable to allocate memory for flash mapping\n");
+			return -ENOMEM;
+		}
+	} else {
+		for (u = size; u > 1; u >>= 1)
+			;
+		if (u != 1) {
+			printk(KERN_ERR NAME ": invalid size for flash mapping\n");
+			return -EINVAL;
+		}
+		
+		if (width != 8 && width != 16) {
+			printk(KERN_ERR NAME ": invalid bus width for flash mapping\n");
+			return -EINVAL;
+		}
+		
+		if (allocate_resource(&iomem_resource, &docmem, 
+				      size,
+				      0xc0000000, 0xffffffff, 
+				      size, NULL, NULL)) {
+			printk(KERN_ERR NAME ": unable to allocate memory for flash mapping\n");
+			return -ENOMEM;
+		}
+		
+		ctrl = 0x07000000 | ((size-1) >> 13);
+
+		printk(KERN_INFO "DOCCS BASE=0x%08lx, CTRL=0x%08lx\n", (long)docmem.start, (long)ctrl);
+		
+		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);
+		
+		if (width == 8) {
+			pmr &= ~(1<<6);
+		} else {
+			pmr |= (1<<6);
+		}
+		outl(pmr, SCx200_CB_BASE + SCx200_PMR);
+	}
+	
+       	printk(KERN_INFO NAME ": DOCCS mapped at 0x%lx-0x%lx, width %d\n", 
+	       docmem.start, docmem.end, width);
+
+	scx200_docflash_map.size = size;
+	if (width == 8)
+		scx200_docflash_map.buswidth = 1;
+	else
+		scx200_docflash_map.buswidth = 2;
+
+	scx200_docflash_map.map_priv_1 = (unsigned long)ioremap(docmem.start, scx200_docflash_map.size);
+	if (!scx200_docflash_map.map_priv_1) {
+		printk(KERN_ERR NAME ": failed to ioremap the flash\n");
+		release_resource(&docmem);
+		return -EIO;
+	}
+
+	mymtd = do_map_probe(flashtype, &scx200_docflash_map);
+	if (!mymtd) {
+		printk(KERN_ERR NAME ": unable to detect flash\n");
+		iounmap((void *)scx200_docflash_map.map_priv_1);
+		release_resource(&docmem);
+		return -ENXIO;
+	}
+
+	if (size < mymtd->size)
+		printk(KERN_WARNING NAME ": warning, flash mapping is smaller than flash size\n");
+
+	mymtd->module = THIS_MODULE;
+
+#if PARTITION
+	partition_info[3].offset = mymtd->size-partition_info[3].size;
+	partition_info[2].size = partition_info[3].offset-partition_info[2].offset;
+	add_mtd_partitions(mymtd, partition_info, NUM_PARTITIONS);
+#else
+	add_mtd_device(mymtd);
+#endif
+	return 0;
+}
+
+static void __exit cleanup_scx200_docflash(void)
+{
+	if (mymtd) {
+#if PARTITION
+		del_mtd_partitions(mymtd);
+#else
+		del_mtd_device(mymtd);
+#endif
+		map_destroy(mymtd);
+	}
+	if (scx200_docflash_map.map_priv_1) {
+		iounmap((void *)scx200_docflash_map.map_priv_1);
+		release_resource(&docmem);
+	}
+}
+
+module_init(init_scx200_docflash);
+module_exit(cleanup_scx200_docflash);
+
+/*
+    Local variables:
+        compile-command: "make -k -C ../../.. SUBDIRS=drivers/mtd/maps modules"
+        c-basic-offset: 8
+    End:
+*/

include/linux/pci_ids.h

@@ -288,6 +288,12 @@
 #define PCI_DEVICE_ID_NS_87560_USB	0x0012
 #define PCI_DEVICE_ID_NS_83815		0x0020
 #define PCI_DEVICE_ID_NS_83820		0x0022
+#define PCI_DEVICE_ID_NS_SCx200_BRIDGE	0x0500
+#define PCI_DEVICE_ID_NS_SCx200_SMI	0x0501
+#define PCI_DEVICE_ID_NS_SCx200_IDE	0x0502
+#define PCI_DEVICE_ID_NS_SCx200_AUDIO	0x0503
+#define PCI_DEVICE_ID_NS_SCx200_VIDEO	0x0504
+#define PCI_DEVICE_ID_NS_SCx200_XBUS	0x0505
 #define PCI_DEVICE_ID_NS_87410		0xd001
 
 #define PCI_VENDOR_ID_TSENG		0x100c

include/linux/scx200.h

+/* linux/include/linux/scx200.h
+
+   Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com>
+
+   Defines for the National Semiconductor SCx200 Processors
+*/
+
+/* Interesting stuff for the National Semiconductor SCx200 CPU */
+
+/* F0 PCI Header/Bridge Configuration Registers */
+#define SCx200_DOCCS_BASE 0x78	/* DOCCS Base Address Register */
+#define SCx200_DOCCS_CTRL 0x7c	/* DOCCS Control Register */
+
+/* GPIO Register Block */
+#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 */
+
+/* Watchdog Timer */
+#define SCx200_WDT_OFFSET 0x00	/* offset within configuration block */
+#define SCx200_WDT_SIZE 0x05	/* size */
+
+#define SCx200_WDT_WDTO 0x00	/* Time-Out Register */
+#define SCx200_WDT_WDCNFG 0x02	/* Configuration Register */
+#define SCx200_WDT_WDSTS 0x04	/* Status Register */
+#define SCx200_WDT_WDSTS_WDOVF (1<<0) /* Overflow bit */
+
+/* High Resolution Timer */
+#define SCx200_TIMER_OFFSET 0x08
+#define SCx200_TIMER_SIZE 0x05
+
+/* Clock Generators */
+#define SCx200_CLOCKGEN_OFFSET 0x10
+#define SCx200_CLOCKGEN_SIZE 0x10
+
+/* Pin Multiplexing and Miscellaneous Configuration Registers */
+#define SCx200_MISC_OFFSET 0x30
+#define SCx200_MISC_SIZE 0x10
+
+#define SCx200_PMR 0x30		/* Pin Multiplexing Register */
+#define SCx200_MCR 0x34		/* Miscellaneous Configuration Register */
+#define SCx200_INTSEL 0x38	/* Interrupt Selection Register */
+#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))
+
+/*
+    Local variables:
+        compile-command: "make -C ../.. bzImage modules"
+        c-basic-offset: 8
+    End:
+*/

include/linux/scx200_gpio.h

+#include <linux/spinlock.h>
+
+u32 scx200_gpio_configure(int index, u32 set, u32 clear);
+void scx200_gpio_dump(unsigned index);
+
+extern unsigned scx200_gpio_base;
+extern spinlock_t scx200_gpio_lock;
+extern long scx200_gpio_shadow[2];
+
+#define scx200_gpio_present() (scx200_gpio_base!=0)
+
+/* Definitions to make sure I do the same thing in all functions */
+#define __SCx200_GPIO_BANK unsigned bank = index>>5
+#define __SCx200_GPIO_IOADDR unsigned short ioaddr = scx200_gpio_base+0x10*bank
+#define __SCx200_GPIO_SHADOW long *shadow = scx200_gpio_shadow+bank
+#define __SCx200_GPIO_INDEX index &= 31
+
+#define __SCx200_GPIO_OUT __asm__ __volatile__("outsl":"=mS" (shadow):"d" (ioaddr), "0" (shadow))
+
+/* returns the value of the GPIO pin */
+
+static inline int scx200_gpio_get(int index) {
+	__SCx200_GPIO_BANK;
+	__SCx200_GPIO_IOADDR + 0x04;
+	__SCx200_GPIO_INDEX;
+		
+	return (inl(ioaddr) & (1<<index)) ? 1 : 0;
+}
+
+/* return the value driven on the GPIO signal (the value that will be
+   driven if the GPIO is configured as an output, it might not be the
+   state of the GPIO right now if the GPIO is configured as an input) */
+
+static inline int scx200_gpio_current(int index) {
+        __SCx200_GPIO_BANK;
+	__SCx200_GPIO_INDEX;
+		
+	return (scx200_gpio_shadow[bank] & (1<<index)) ? 1 : 0;
+}
+
+/* drive the GPIO signal high */
+
+static inline void scx200_gpio_set_high(int index) {
+	__SCx200_GPIO_BANK;
+	__SCx200_GPIO_IOADDR;
+	__SCx200_GPIO_SHADOW;
+	__SCx200_GPIO_INDEX;
+	set_bit(index, shadow);
+	__SCx200_GPIO_OUT;
+}
+
+/* drive the GPIO signal low */
+
+static inline void scx200_gpio_set_low(int index) {
+	__SCx200_GPIO_BANK;
+	__SCx200_GPIO_IOADDR;
+	__SCx200_GPIO_SHADOW;
+	__SCx200_GPIO_INDEX;
+	clear_bit(index, shadow);
+	__SCx200_GPIO_OUT;
+}
+
+/* drive the GPIO signal to state */
+
+static inline void scx200_gpio_set(int index, int state) {
+	__SCx200_GPIO_BANK;
+	__SCx200_GPIO_IOADDR;
+	__SCx200_GPIO_SHADOW;
+	__SCx200_GPIO_INDEX;
+	if (state)
+		set_bit(index, shadow);
+	else
+		clear_bit(index, shadow);
+	__SCx200_GPIO_OUT;
+}
+
+/* toggle the GPIO signal */
+static inline void scx200_gpio_change(int index) {
+	__SCx200_GPIO_BANK;
+	__SCx200_GPIO_IOADDR;
+	__SCx200_GPIO_SHADOW;
+	__SCx200_GPIO_INDEX;
+	change_bit(index, shadow);
+	__SCx200_GPIO_OUT;
+}
+
+#undef __SCx200_GPIO_BANK
+#undef __SCx200_GPIO_IOADDR
+#undef __SCx200_GPIO_SHADOW
+#undef __SCx200_GPIO_INDEX
+#undef __SCx200_GPIO_OUT
+
+/*
+    Local variables:
+        compile-command: "make -C ../.. bzImage modules"
+        c-basic-offset: 8
+    End:
+*/