patch-2.4.19 linux-2.4.19/arch/ppc64/kernel/nvram.c

• Lines: 141
• Date: Fri Aug 2 17:39:43 2002
• Orig file: linux-2.4.18/arch/ppc64/kernel/nvram.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.18/arch/ppc64/kernel/nvram.c linux-2.4.19/arch/ppc64/kernel/nvram.c
@@ -0,0 +1,140 @@
+/*
+ *  c 2001 PPC 64 Team, IBM Corp
+ *
+ *      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.
+ *
+ * /dev/nvram driver for PPC64
+ *
+ * This perhaps should live in drivers/char
+ */
+
+#include <linux/module.h>
+
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/miscdevice.h>
+#include <linux/fcntl.h>
+#include <linux/nvram.h>
+#include <linux/init.h>
+#include <asm/uaccess.h>
+#include <asm/nvram.h>
+#include <asm/rtas.h>
+#include <asm/prom.h>
+
+static unsigned int rtas_nvram_size;
+static unsigned int nvram_fetch, nvram_store;
+static char nvram_buf[4];	/* assume this is in the first 4GB */
+
+static loff_t nvram_llseek(struct file *file, loff_t offset, int origin)
+{
+	switch (origin) {
+	case 1:
+		offset += file->f_pos;
+		break;
+	case 2:
+		offset += rtas_nvram_size;
+		break;
+	}
+	if (offset < 0)
+		return -EINVAL;
+	file->f_pos = offset;
+	return file->f_pos;
+}
+
+
+static ssize_t read_nvram(struct file *file, char *buf,
+			  size_t count, loff_t *ppos)
+{
+	unsigned int i;
+	unsigned long len;
+	char *p = buf;
+
+	if (verify_area(VERIFY_WRITE, buf, count))
+		return -EFAULT;
+	if (*ppos >= rtas_nvram_size)
+		return 0;
+	for (i = *ppos; count > 0 && i < rtas_nvram_size; ++i, ++p, --count) {
+		if ((rtas_call(nvram_fetch, 3, 2, &len, i, __pa(nvram_buf), 1) != 0) ||
+		    len != 1)
+			return -EIO;
+		if (__put_user(nvram_buf[0], p))
+			return -EFAULT;
+	}
+	*ppos = i;
+	return p - buf;
+}
+
+static ssize_t write_nvram(struct file *file, const char *buf,
+			   size_t count, loff_t *ppos)
+{
+	unsigned int i;
+	unsigned long len;
+	const char *p = buf;
+	char c;
+
+	if (verify_area(VERIFY_READ, buf, count))
+		return -EFAULT;
+	if (*ppos >= rtas_nvram_size)
+		return 0;
+	for (i = *ppos; count > 0 && i < rtas_nvram_size; ++i, ++p, --count) {
+		if (__get_user(c, p))
+			return -EFAULT;
+		nvram_buf[0] = c;
+		if ((rtas_call(nvram_store, 3, 2, &len, i, __pa(nvram_buf), 1) != 0) ||
+		    len != 1)
+			return -EIO;
+	}
+	*ppos = i;
+	return p - buf;
+}
+
+static int nvram_ioctl(struct inode *inode, struct file *file,
+	unsigned int cmd, unsigned long arg)
+{
+	return -EINVAL;
+}
+
+struct file_operations nvram_fops = {
+	owner:		THIS_MODULE,
+	llseek:		nvram_llseek,
+	read:		read_nvram,
+	write:		write_nvram,
+	ioctl:		nvram_ioctl,
+};
+
+static struct miscdevice nvram_dev = {
+	NVRAM_MINOR,
+	"nvram",
+	&nvram_fops
+};
+
+int __init nvram_init(void)
+{
+	struct device_node *nvram;
+	unsigned int *nbytes_p, proplen;
+	if ((nvram = find_type_devices("nvram")) != NULL) {
+		nbytes_p = (unsigned int *)get_property(nvram, "#bytes", &proplen);
+		if (nbytes_p && proplen == sizeof(unsigned int)) {
+			rtas_nvram_size = *nbytes_p;
+		}
+	}
+	nvram_fetch = rtas_token("nvram-fetch");
+	nvram_store = rtas_token("nvram-store");
+	printk(KERN_INFO "PPC64 nvram contains %d bytes\n", rtas_nvram_size);
+
+	misc_register(&nvram_dev);
+	return 0;
+}
+
+void __exit nvram_cleanup(void)
+{
+        misc_deregister( &nvram_dev );
+}
+
+module_init(nvram_init);
+module_exit(nvram_cleanup);
+MODULE_LICENSE("GPL");