patch-2.4.0-test3 linux/drivers/mtd/docprobe.c

• Lines: 271
• Date: Thu Jul 6 01:22:24 2000
• Orig file: v2.4.0-test2/linux/drivers/mtd/docprobe.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.0-test2/linux/drivers/mtd/docprobe.c linux/drivers/mtd/docprobe.c
@@ -0,0 +1,270 @@
+
+/* Linux driver for Disk-On-Chip devices    */
+/* Probe routines common to all DoC devices */
+/* (c) 1999 Machine Vision Holdings, Inc.   */
+/* Author: David Woodhouse <dwmw2@mvhi.com> */
+/* $Id: docprobe.c,v 1.8 2000/06/26 20:40:53 dwmw2 Exp $ */
+
+
+
+/* DOC_PASSIVE_PROBE:
+   In order to ensure that the BIOS checksum is correct at boot time, and 
+   hence that the onboard BIOS extension gets executed, the DiskOnChip 
+   goes into reset mode when it is read sequentially: all registers 
+   return 0xff until the chip is woken up again by writing to the 
+   DOCControl register. 
+
+   Unfortunately, this means that the probe for the DiskOnChip is unsafe, 
+   because one of the first things it does is write to where it thinks 
+   the DOCControl register should be - which may well be shared memory 
+   for another device. I've had machines which lock up when this is 
+   attempted. Hence the possibility to do a passive probe, which will fail 
+   to detect a chip in reset mode, but is at least guaranteed not to lock
+   the machine.
+
+   If you have this problem, uncomment the following line:
+#define DOC_PASSIVE_PROBE
+*/
+
+
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/kmod.h>
+#include <asm/errno.h>
+#include <asm/io.h>
+#include <asm/uaccess.h>
+#include <linux/miscdevice.h>
+#include <linux/pci.h>
+#include <linux/delay.h>
+#include <linux/malloc.h>
+#include <linux/sched.h>
+#include <linux/init.h>
+#include <linux/types.h>
+
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand.h>
+#include <linux/mtd/doc2000.h>
+
+/* Where to look for the devices? */
+
+#if defined (__alpha__) || defined(__i386__)
+static unsigned long __initdata doc_locations[] = { 
+		0xc8000, 0xca000, 0xcc000, 0xce000, 
+		0xd0000, 0xd2000, 0xd4000, 0xd6000,
+		0xd8000, 0xda000, 0xdc000, 0xde000, 
+		0xe0000, 0xe2000, 0xe4000, 0xe6000, 
+		0xe8000, 0xea000, 0xec000, 0xee000, 0 };
+#elif defined(__ppc__)
+static unsigned long __initdata doc_locations[] = {
+		0xe4000000, 0};
+#else 
+#warning Unknown architecture for DiskOnChip. No default probe locations defined
+#endif
+
+#ifdef CONFIG_MTD_DOC2000
+extern void DoC2k_init(struct mtd_info *);
+#endif
+#ifdef CONFIG_MTD_DOC2001
+extern void DoCMil_init(struct mtd_info *);
+#endif
+
+/* doccheck: Probe a given memory window to see if there's a DiskOnChip present */
+
+static inline int __init doccheck(unsigned long potential, unsigned long physadr)
+{
+	unsigned long window=potential;
+	unsigned char tmp, ChipID;
+#ifndef DOC_PASSIVE_PROBE
+	unsigned char tmp2;
+#endif
+
+	/* Routine copied from the Linux DOC driver */
+	
+	/* Check for 0x55 0xAA signature at beginning of window */
+	if (ReadDOC(window, Sig1) != 0x55 || ReadDOC(window, Sig2) != 0xaa)
+		return 0;
+
+#ifndef DOC_PASSIVE_PROBE	
+	/* It's not possible to cleanly detect the DiskOnChip - the
+	 * bootup procedure will put the device into reset mode, and
+	 * it's not possible to talk to it without actually writing
+	 * to the DOCControl register. So we store the current contents
+	 * of the DOCControl register's location, in case we later decide
+	 * that it's not a DiskOnChip, and want to put it back how we
+	 * found it. 
+	 */
+	tmp2 = ReadDOC(window, DOCControl);
+	
+	/* Reset the DiskOnChip ASIC */
+	WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_RESET, 
+		 window, DOCControl);
+	WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_RESET, 
+		 window, DOCControl);
+	
+	/* Enable the DiskOnChip ASIC */
+	WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_NORMAL, 
+		 window, DOCControl);
+	WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_NORMAL, 
+		 window, DOCControl);
+#endif /* !DOC_PASSIVE_PROBE */	
+
+	ChipID = ReadDOC(window, ChipID);
+  
+	switch (ChipID) {
+	case DOC_ChipID_Doc2k:
+		/* Check the TOGGLE bit in the ECC register */
+		tmp = ReadDOC(window, 2k_ECCStatus) & DOC_TOGGLE_BIT;
+		if ((ReadDOC(window, 2k_ECCStatus) & DOC_TOGGLE_BIT) != tmp)
+				return ChipID;
+		break;
+		
+	case DOC_ChipID_DocMil:
+		/* Check the TOGGLE bit in the ECC register */
+		tmp = ReadDOC(window, ECCConf) & DOC_TOGGLE_BIT;
+		if ((ReadDOC(window, ECCConf) & DOC_TOGGLE_BIT) != tmp)
+				return ChipID;
+		break;
+		
+	default:
+		printk(KERN_WARNING "Possible DiskOnChip with unknown ChipID %2.2X found at 0x%lx\n",
+		       ChipID, physadr);
+
+#ifndef DOC_PASSIVE_PROBE
+		/* Put back the contents of the DOCControl register, in case it's not
+		 * actually a DiskOnChip.
+		 */
+		WriteDOC(tmp2, window, DOCControl);
+#endif
+		return 0;
+	}
+
+	printk(KERN_WARNING "DiskOnChip failed TOGGLE test, dropping.\n");
+
+#ifndef DOC_PASSIVE_PROBE
+	/* Put back the contents of the DOCControl register: it's not a DiskOnChip */
+	WriteDOC(tmp2, window, DOCControl);
+#endif
+	return 0;
+}   
+
+
+static void DoC_Probe(unsigned long physadr)
+{
+	unsigned long docptr;
+	struct DiskOnChip *this;
+	struct mtd_info *mtd;
+	int ChipID;
+	char namebuf[15];
+	char *name = namebuf;
+	void (*initroutine)(struct mtd_info *) = NULL;
+	int initroutinedynamic = 0;
+
+	docptr = (unsigned long)ioremap(physadr, 0x2000);
+	
+	if (!docptr)
+		return;
+	
+	if ((ChipID = doccheck(docptr, physadr))) {
+		
+		mtd = kmalloc(sizeof(struct DiskOnChip) + sizeof(struct mtd_info), GFP_KERNEL);
+
+		if (!mtd) {
+			printk("Cannot allocate memory for data structures. Dropping.\n");
+			iounmap((void *)docptr);
+			return;
+		}
+		
+		this = (struct DiskOnChip *)(&mtd[1]);
+		
+		memset((char *)mtd,0, sizeof(struct mtd_info));
+		memset((char *)this, 0, sizeof(struct DiskOnChip));
+
+		mtd->priv = this;
+		this->virtadr = docptr;
+		this->physadr = physadr;
+		this->ChipID = ChipID;
+		sprintf(namebuf, "with ChipID %2.2X", ChipID);
+		
+		switch(ChipID) {
+		case DOC_ChipID_Doc2k:
+			name="2000";
+#ifdef CONFIG_MTD_DOC2000
+			initroutine = &DoC2k_init;
+#elif CONFIG_MODULES
+			initroutinedynamic=1;
+			initroutine = (void *)get_module_symbol(NULL, "DoC2k_init");
+#ifdef CONFIG_KMOD
+			if (!initroutine) {
+				request_module("doc2000");
+				initroutine = (void *)get_module_symbol("doc2000", "DoC2k_init");
+			}
+#endif /* CONFIG_KMOD */
+#endif
+			break;
+
+		case DOC_ChipID_DocMil:
+			name="Millennium";
+#ifdef CONFIG_MTD_DOC2001
+			initroutine = &DocMil_init;
+#elif CONFIG_MODULES
+			initroutinedynamic=1;
+			initroutine = (void *)get_module_symbol(NULL, "DoCMil_init");
+#ifdef CONFIG_KMOD
+			if (!initroutine) {
+				request_module("doc2001");
+				initroutine = (void *)get_module_symbol("doc2001", "DoCMil_init");
+			}
+#endif /* CONFIG_KMOD */
+#endif
+			break;
+		}
+		if (initroutine) {
+			(*initroutine)(mtd);
+#if defined(CONFIG_MODULES) && LINUX_VERSION_CODE >= 0x20400
+			if (initroutinedynamic)
+				put_module_symbol(initroutine);
+#endif
+			return;
+		}
+		printk("Cannot find driver for DiskOnChip %s at 0x%X\n", name, physadr);
+	}
+	iounmap((void *)docptr);
+}
+
+
+/****************************************************************************
+ *
+ * Module stuff
+ *
+ ****************************************************************************/
+
+#if LINUX_VERSION_CODE < 0x20300
+#ifdef MODULE
+#define init_doc init_module
+#endif
+#define __exit
+#endif
+
+int __init init_doc(void)
+{
+	int i;
+	
+	printk(KERN_NOTICE "M-Systems DiskOnChip driver. (C) 1999 Machine Vision Holdings, Inc.\n");
+#ifdef PRERELEASE
+	printk(KERN_INFO "$Id: docprobe.c,v 1.8 2000/06/26 20:40:53 dwmw2 Exp $\n");
+#endif
+	
+	for (i=0; doc_locations[i]; i++) {
+		DoC_Probe(doc_locations[i]);
+	}
+	
+	return 0;
+	
+}
+
+
+#if LINUX_VERSION_CODE > 0x20300
+module_init(init_doc);
+#endif
+