patch-2.3.35 linux/drivers/sbus/char/jsflash.c

• Lines: 416
• Date: Mon Dec 20 22:06:42 1999
• Orig file: v2.3.34/linux/drivers/sbus/char/jsflash.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.34/linux/drivers/sbus/char/jsflash.c linux/drivers/sbus/char/jsflash.c
@@ -0,0 +1,415 @@
+/*
+ * drivers/sbus/char/jsflash.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds	(drivers/char/mem.c)
+ *  Copyright (C) 1997  Eddie C. Dost		(drivers/sbus/char/flash.c)
+ *  Copyright (C) 1999  Pete Zaitcev
+ *
+ * This driver is used to program OS into a Flash SIMM on
+ * Krups and Espresso platforms.
+ *
+ * It is anticipated that programming an OS Flash will be a routine
+ * procedure. In the same time it is exeedingly dangerous because
+ * a user can program its OBP flash with OS image and effectively
+ * kill the machine.
+ *
+ * This driver uses an interface different from Eddie's flash.c
+ * as a silly safeguard.
+ *
+ * XXX The flash.c manipulates page caching characteristics in a certain
+ * dubious way; also it assumes that remap_page_range() can remap
+ * PCI bus locations, which may be false. ioremap() must be used
+ * instead. We should discuss this.
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/miscdevice.h>
+#include <linux/malloc.h>
+#include <linux/fcntl.h>
+#include <linux/poll.h>
+#include <linux/init.h>
+#if 0	/* P3 from mem.c */
+#include <linux/mm.h>
+#include <linux/vmalloc.h>
+#include <linux/mman.h>
+#include <linux/random.h>
+#include <linux/raw.h>
+#include <linux/capability.h>
+#endif
+
+#include <asm/uaccess.h>
+#include <asm/pgtable.h>
+#include <asm/io.h>
+#if 0	/* P3 from mem.c */
+#include <asm/system.h>
+#include <asm/sbus.h>
+#include <asm/ebus.h>
+#endif
+
+#include <asm/jsflash.h>		/* ioctl arguments. <linux/> ?? */
+#define JSFIDSZ		(sizeof(struct jsflash_ident_arg))
+#define JSFPRGSZ	(sizeof(struct jsflash_program_arg))
+
+/*
+ * Our device numbers have no business in system headers.
+ * The only thing a user knows is the device name /dev/jsflash.
+ */
+#define JSF_MINOR	178
+
+/*
+ * Access functions.
+ * We could ioremap(), but it's easier this way.
+ */
+static unsigned int jsf_inl(unsigned long addr)
+{
+	unsigned long retval;
+
+	__asm__ __volatile__("lda [%1] %2, %0\n\t" :
+				"=r" (retval) :
+				"r" (addr), "i" (ASI_M_BYPASS));
+        return retval;
+}
+
+static void jsf_outl(unsigned long addr, __u32 data)
+{
+
+	__asm__ __volatile__("sta %0, [%1] %2\n\t" : :
+				"r" (data), "r" (addr), "i" (ASI_M_BYPASS) :
+				"memory");
+}
+
+/*
+ * soft carrier
+ */
+struct jsflash {
+	unsigned long base;
+	unsigned long size;
+	unsigned long busy;		/* In use? */
+	struct jsflash_ident_arg id;
+};
+
+/*
+ * We do not map normal memory or obio as a safety precaution.
+ * But offsets are real, for ease of userland programming.
+ */
+#define JSF_BASE_TOP	0x30000000
+#define JSF_BASE_ALL	0x20000000
+
+#define JSF_BASE_JK	0x20400000
+
+/*
+ * Let's pretend we may have several of these...
+ */
+static struct jsflash jsf0;
+
+/*
+ * Wait for AMD to finish its embedded algorithm.
+ * We use the Toggle bit DQ6 (0x40) because it does not
+ * depend on the data value as /DATA bit DQ7 does.
+ *
+ * XXX Do we need any timeout here?
+ */
+static void jsf_wait(unsigned long p) {
+	unsigned int x1, x2;
+
+	for (;;) {
+		x1 = jsf_inl(p);
+		x2 = jsf_inl(p);
+		if ((x1 & 0x40404040) == (x2 & 0x40404040)) return;
+	}
+}
+
+/*
+ * Programming will only work if Flash is clean,
+ * we leave it to the programmer application.
+ *
+ * AMD must be programmed one byte at a time;
+ * thus, Simple Tech SIMM must be written 4 bytes at a time.
+ *
+ * Write waits for the chip to become ready after the write
+ * was finished. This is done so that application would read
+ * consistent data after the write is done.
+ */
+static void jsf_write4(unsigned long fa, u32 data) {
+
+	jsf_outl(fa, 0xAAAAAAAA);		/* Unlock 1 Write 1 */
+	jsf_outl(fa, 0x55555555);		/* Unlock 1 Write 2 */
+	jsf_outl(fa, 0xA0A0A0A0);		/* Byte Program */
+	jsf_outl(fa, data);
+
+	jsf_wait(fa);
+}
+
+/*
+ * The memory devices use the full 32/64 bits of the offset, and so we cannot
+ * check against negative addresses: they are ok. The return value is weird,
+ * though, in that case (0).
+ *
+ * also note that seeking relative to the "end of file" isn't supported:
+ * it has no meaning, so it returns -EINVAL.
+ */
+static loff_t jsf_lseek(struct file * file, loff_t offset, int orig)
+{
+	switch (orig) {
+		case 0:
+			file->f_pos = offset;
+			return file->f_pos;
+		case 1:
+			file->f_pos += offset;
+			return file->f_pos;
+		default:
+			return -EINVAL;
+	}
+}
+
+/*
+ * P3: OS SIMM Cannot be read in other size but a 32bits word.
+ */
+static ssize_t jsf_read(struct file * file, char * buf, 
+    size_t togo, loff_t *ppos)
+{
+	unsigned long p = *ppos;
+	char *tmp = buf;
+
+	union byte4 {
+		char s[4];
+		unsigned int n;
+	} b;
+
+	if (verify_area(VERIFY_WRITE, buf, togo))
+		return -EFAULT; 
+
+	if (p < JSF_BASE_ALL || p >= JSF_BASE_TOP) {
+		return 0;
+	}
+
+	if ((p + togo) < p	/* wrap */
+	   || (p + togo) >= JSF_BASE_TOP) {
+		togo = JSF_BASE_TOP - p;
+	}
+
+	if (p < JSF_BASE_ALL && togo != 0) {
+		size_t x = JSF_BASE_ALL - p;
+		if (x > togo) x = togo;
+		clear_user(tmp, x);
+		tmp += x;
+		p += x;
+		togo -= x;
+	}
+
+	while (togo >= 4) {
+		togo -= 4;
+		b.n = jsf_inl(p);
+		copy_to_user(tmp, b.s, 4);
+		tmp += 4;
+		p += 4;
+	}
+
+	/*
+	 * XXX Small togo may remain if 1 byte is ordered.
+	 * It would be nice if we did a word size read and unpacked it.
+	 */
+
+	*ppos = p;
+	return tmp-buf;
+}
+
+static ssize_t jsf_write(struct file * file, const char * buf,
+    size_t count, loff_t *ppos)
+{
+	return -ENOSPC;
+}
+
+/*
+ */
+static int jsf_ioctl_erase(unsigned long arg)
+{
+	unsigned long p;
+
+	/* p = jsf0.base;	hits wrong bank */
+	p = 0x20400000;
+
+	jsf_outl(p, 0xAAAAAAAA);		/* Unlock 1 Write 1 */
+	jsf_outl(p, 0x55555555);		/* Unlock 1 Write 2 */
+	jsf_outl(p, 0x80808080);		/* Erase setup */
+	jsf_outl(p, 0xAAAAAAAA);		/* Unlock 2 Write 1 */
+	jsf_outl(p, 0x55555555);		/* Unlock 2 Write 2 */
+	jsf_outl(p, 0x10101010);		/* Chip erase */
+
+#if 0
+	/*
+	 * This code is ok, except that counter based timeout
+	 * has no place in this world. Let's just drop timeouts...
+	 */
+	{
+		int i;
+		__u32 x;
+		for (i = 0; i < 1000000; i++) {
+			x = jsf_inl(p);
+			if ((x & 0x80808080) == 0x80808080) break;
+		}
+		if ((x & 0x80808080) != 0x80808080) {
+			printk("jsf0: erase timeout with 0x%08x\n", x);
+		} else {
+			printk("jsf0: erase done with 0x%08x\n", x);
+		}
+	}
+#else
+	jsf_wait(p);
+#endif
+
+	return 0;
+}
+
+/*
+ * Program a block of flash.
+ * Very simple because we can do it byte by byte anyway.
+ */
+static int jsf_ioctl_program(unsigned long arg)
+{
+	struct jsflash_program_arg abuf;
+	char *uptr;
+	unsigned long p;
+	unsigned int togo;
+	union {
+		unsigned int n;
+		char s[4];
+	} b;
+
+	if (verify_area(VERIFY_READ, (void *)arg, JSFPRGSZ))
+		return -EFAULT; 
+	copy_from_user(&abuf, (char *)arg, JSFPRGSZ);
+	p = abuf.off;
+	togo = abuf.size;
+	if ((togo & 3) || (p & 3)) return -EINVAL;
+
+	uptr = (char *) abuf.data;
+	if (verify_area(VERIFY_READ, uptr, togo))
+		return -EFAULT;
+	while (togo != 0) {
+		--togo;
+		copy_from_user(&b.s[0], uptr, 4);
+		jsf_write4(p, b.n);
+		p += 4;
+		uptr += 4;
+	}
+
+	return 0;
+}
+
+static int jsf_ioctl(struct inode *inode, struct file *f, unsigned int cmd,
+    unsigned long arg)
+{
+	int error = -ENOTTY;
+
+	switch (cmd) {
+	case JSFLASH_IDENT:
+		if (verify_area(VERIFY_WRITE, (void *)arg, JSFIDSZ))
+			return -EFAULT; 
+		copy_to_user(arg, &jsf0.id, JSFIDSZ);
+		error = 0;
+		break;
+	case JSFLASH_ERASE:
+		error = jsf_ioctl_erase(arg);
+		break;
+	case JSFLASH_PROGRAM:
+		error = jsf_ioctl_program(arg);
+		break;
+	}
+
+	return error;
+}
+
+static int jsf_mmap(struct file * file, struct vm_area_struct * vma)
+{
+	return -ENXIO;
+}
+
+static int jsf_open(struct inode * inode, struct file * filp)
+{
+
+	if (jsf0.base == 0) return -ENXIO;
+	if (test_and_set_bit(0, (void *)&jsf0.busy) != 0)
+		return -EBUSY;
+
+	MOD_INC_USE_COUNT;
+	return 0;	/* XXX What security? */
+}
+
+static int jsf_release(struct inode *inode, struct file *file)
+{
+
+	MOD_DEC_USE_COUNT;
+
+	jsf0.busy = 0;
+	return 0;
+}
+
+static struct file_operations jsf_fops = {
+	jsf_lseek,
+	jsf_read,
+	jsf_write,
+	NULL,		/* readdir */
+	NULL,		/* poll */
+	jsf_ioctl,
+	jsf_mmap,
+	jsf_open,
+	NULL,		/* flush */
+	jsf_release,
+	NULL		/* fsync */
+};
+
+static struct miscdevice jsf_dev = { JSF_MINOR, "jsflash", &jsf_fops };
+
+EXPORT_NO_SYMBOLS;
+
+#ifdef MODULE
+int init_module(void)
+#else
+int /* __init */ jsflash_init(void)
+#endif
+{
+	int rc;
+
+	/* extern enum sparc_cpu sparc_cpu_model; */ /* in <asm/system.h> */
+	if (sparc_cpu_model == sun4m && jsf0.base == 0) {
+		/* XXX Autodetect */
+		/*
+		 * We do not want to use PROM properties;
+		 * They are faked by PROLL anyways.
+		 */
+		jsf0.base = JSF_BASE_JK;
+		jsf0.size = 0x00800000;		/* 8M */
+
+		jsf0.id.off = JSF_BASE_ALL;
+		jsf0.id.size = 0x01000000;	/* 16M - all segments */
+		strcpy(jsf0.id.name, "Krups_all");
+
+		printk("Espresso Flash @0x%lx\n", jsf0.base);
+	}
+
+	if ((rc = misc_register(&jsf_dev)) != 0) {
+		printk(KERN_ERR "jsf: unable to get misc minor %d\n",
+		    JSF_MINOR);
+		jsf0.base = 0;
+		return rc;
+	}
+	return 0;
+}
+
+#ifdef MODULE
+void cleanup_module(void)
+{
+
+	/* for (all probed units) {  } */
+	if (jsf0.busy)
+		printk("jsf0: cleaning busy unit\n");
+	jsf0.base = 0;
+	jsf0.busy = 0;
+
+	misc_deregister(&jsf_dev);
+}
+#endif