patch-2.4.6 linux/drivers/mtd/devices/docprobe.c

• Lines: 286
• Date: Tue Jun 12 10:30:27 2001
• Orig file: v2.4.5/linux/drivers/mtd/devices/docprobe.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.5/linux/drivers/mtd/devices/docprobe.c linux/drivers/mtd/devices/docprobe.c
@@ -0,0 +1,285 @@
+
+/* Linux driver for Disk-On-Chip devices			*/
+/* Probe routines common to all DoC devices			*/
+/* (c) 1999 Machine Vision Holdings, Inc.			*/
+/* Author: David Woodhouse <dwmw2@infradead.org>		*/
+/* $Id: docprobe.c,v 1.27 2001/06/03 19:06:09 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
+*/
+
+
+/* DOC_SINGLE_DRIVER:
+   Millennium driver has been merged into DOC2000 driver.
+
+   The newly-merged driver doesn't appear to work for writing. It's the
+   same with the DiskOnChip 2000 and the Millennium. If you have a 
+   Millennium and you want write support to work, remove the definition
+   of DOC_SINGLE_DRIVER below to use the old doc2001-specific driver.
+
+   Otherwise, it's left on in the hope that it'll annoy someone with
+   a Millennium enough that they go through and work out what the 
+   difference is :)
+*/
+#define DOC_SINGLE_DRIVER
+
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/module.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/slab.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? */
+#ifndef CONFIG_MTD_DOCPROBE_ADDRESS
+#define CONFIG_MTD_DOCPROBE_ADDRESS 0
+#endif
+
+
+static unsigned long doc_config_location = CONFIG_MTD_DOCPROBE_ADDRESS;
+MODULE_PARM(doc_config_location, "l");
+
+
+static unsigned long __initdata doc_locations[] = {
+#if defined (__alpha__) || defined(__i386__)
+#ifdef CONFIG_MTD_DOCPROBE_HIGH
+	0xfffc8000, 0xfffca000, 0xfffcc000, 0xfffce000, 
+	0xfffd0000, 0xfffd2000, 0xfffd4000, 0xfffd6000,
+	0xfffd8000, 0xfffda000, 0xfffdc000, 0xfffde000, 
+	0xfffe0000, 0xfffe2000, 0xfffe4000, 0xfffe6000, 
+	0xfffe8000, 0xfffea000, 0xfffec000, 0xfffee000,
+#else /*  CONFIG_MTD_DOCPROBE_HIGH */
+	0xc8000, 0xca000, 0xcc000, 0xce000, 
+	0xd0000, 0xd2000, 0xd4000, 0xd6000,
+	0xd8000, 0xda000, 0xdc000, 0xde000, 
+	0xe0000, 0xe2000, 0xe4000, 0xe6000, 
+	0xe8000, 0xea000, 0xec000, 0xee000,
+#endif /*  CONFIG_MTD_DOCPROBE_HIGH */
+#elif defined(__ppc__)
+	0xe4000000,
+#elif defined(CONFIG_MOMENCO_OCELOT)
+	0x2f000000,
+#else
+#warning Unknown architecture for DiskOnChip. No default probe locations defined
+#endif
+	0 };
+
+/* 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 */
+
+#ifdef CONFIG_MTD_DOCPROBE_55AA
+	/* Check for 0x55 0xAA signature at beginning of window,
+	   this is no longer true once we remove the IPL (for Millennium */
+	if (ReadDOC(window, Sig1) != 0x55 || ReadDOC(window, Sig2) != 0xaa)
+		return 0;
+#endif /* CONFIG_MTD_DOCPROBE_55AA */
+
+#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:
+#ifndef CONFIG_MTD_DOCPROBE_55AA
+		printk(KERN_WARNING "Possible DiskOnChip with unknown ChipID %2.2X found at 0x%lx\n",
+		       ChipID, physadr);
+#endif
+#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 __init DoC_Probe(unsigned long physadr)
+{
+	unsigned long docptr;
+	struct DiskOnChip *this;
+	struct mtd_info *mtd;
+	int ChipID;
+	char namebuf[15];
+	char *name = namebuf;
+	char *im_funcname = NULL;
+	char *im_modname = NULL;
+	void (*initroutine)(struct mtd_info *) = NULL;
+
+	docptr = (unsigned long)ioremap(physadr, DOC_IOREMAP_LEN);
+	
+	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";
+			im_funcname = "DoC2k_init";
+			im_modname = "doc2000";
+			break;
+			
+		case DOC_ChipID_DocMil:
+			name="Millennium";
+#ifdef DOC_SINGLE_DRIVER
+			im_funcname = "DoC2k_init";
+			im_modname = "doc2000";
+#else
+			im_funcname = "DoCMil_init";
+			im_modname = "doc2001";
+#endif /* DOC_SINGLE_DRIVER */
+			break;
+		}
+
+		if (im_funcname)
+			initroutine = inter_module_get_request(im_funcname, im_modname);
+
+		if (initroutine) {
+			(*initroutine)(mtd);
+			inter_module_put(im_funcname);
+			return;
+		}
+		printk("Cannot find driver for DiskOnChip %s at 0x%lX\n", name, physadr);
+	}
+	iounmap((void *)docptr);
+}
+
+
+/****************************************************************************
+ *
+ * Module stuff
+ *
+ ****************************************************************************/
+
+#if LINUX_VERSION_CODE < 0x20212 && defined(MODULE)
+#define init_doc init_module
+#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 1.27 2001/06/03 19:06:09 dwmw2 Exp $\n");
+#endif
+	if (doc_config_location) {
+		printk("Using configured probe address 0x%lx\n", doc_config_location);
+		DoC_Probe(doc_config_location);
+	} else {
+		for (i=0; doc_locations[i]; i++) {
+			DoC_Probe(doc_locations[i]);
+		}
+	}
+	/* So it looks like we've been used and we get unloaded */
+	MOD_INC_USE_COUNT;
+	MOD_DEC_USE_COUNT;
+	return 0;
+	
+}
+
+module_init(init_doc);
+