1 files changed, 159 insertions, 0 deletions
diff --git a/drivers/char/generic_nvram.c b/drivers/char/generic_nvram.c
new file mode 100644
index 000000000..14e728fbb
--- /dev/null
+++ b/drivers/char/generic_nvram.c
@@ -0,0 +1,159 @@
+/*
+ * Generic /dev/nvram driver for architectures providing some
+ * "generic" hooks, that is :
+ *
+ * nvram_read_byte, nvram_write_byte, nvram_sync, nvram_get_size
+ *
+ * Note that an additional hook is supported for PowerMac only
+ * for getting the nvram "partition" informations
+ *
+ */
+
+#define NVRAM_VERSION "1.1"
+
+#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/init.h>
+#include <linux/mutex.h>
+#include <linux/pagemap.h>
+#include <linux/uaccess.h>
+#include <asm/nvram.h>
+#ifdef CONFIG_PPC_PMAC
+#include <asm/machdep.h>
+#endif
+
+#define NVRAM_SIZE	8192
+
+static DEFINE_MUTEX(nvram_mutex);
+static ssize_t nvram_len;
+
+static loff_t nvram_llseek(struct file *file, loff_t offset, int origin)
+{
+	return generic_file_llseek_size(file, offset, origin,
+					MAX_LFS_FILESIZE, nvram_len);
+}
+
+static ssize_t read_nvram(struct file *file, char __user *buf,
+			  size_t count, loff_t *ppos)
+{
+	unsigned int i;
+	char __user *p = buf;
+
+	if (!access_ok(VERIFY_WRITE, buf, count))
+		return -EFAULT;
+	if (*ppos >= nvram_len)
+		return 0;
+	for (i = *ppos; count > 0 && i < nvram_len; ++i, ++p, --count)
+		if (__put_user(nvram_read_byte(i), p))
+			return -EFAULT;
+	*ppos = i;
+	return p - buf;
+}
+
+static ssize_t write_nvram(struct file *file, const char __user *buf,
+			   size_t count, loff_t *ppos)
+{
+	unsigned int i;
+	const char __user *p = buf;
+	char c;
+
+	if (!access_ok(VERIFY_READ, buf, count))
+		return -EFAULT;
+	if (*ppos >= nvram_len)
+		return 0;
+	for (i = *ppos; count > 0 && i < nvram_len; ++i, ++p, --count) {
+		if (__get_user(c, p))
+			return -EFAULT;
+		nvram_write_byte(c, i);
+	}
+	*ppos = i;
+	return p - buf;
+}
+
+static int nvram_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	switch(cmd) {
+#ifdef CONFIG_PPC_PMAC
+	case OBSOLETE_PMAC_NVRAM_GET_OFFSET:
+		printk(KERN_WARNING "nvram: Using obsolete PMAC_NVRAM_GET_OFFSET ioctl\n");
+	case IOC_NVRAM_GET_OFFSET: {
+		int part, offset;
+
+		if (!machine_is(powermac))
+			return -EINVAL;
+		if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0)
+			return -EFAULT;
+		if (part < pmac_nvram_OF || part > pmac_nvram_NR)
+			return -EINVAL;
+		offset = pmac_get_partition(part);
+		if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0)
+			return -EFAULT;
+		break;
+	}
+#endif /* CONFIG_PPC_PMAC */
+	case IOC_NVRAM_SYNC:
+		nvram_sync();
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static long nvram_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	int ret;
+
+	mutex_lock(&nvram_mutex);
+	ret = nvram_ioctl(file, cmd, arg);
+	mutex_unlock(&nvram_mutex);
+
+	return ret;
+}
+
+const struct file_operations nvram_fops = {
+	.owner		= THIS_MODULE,
+	.llseek		= nvram_llseek,
+	.read		= read_nvram,
+	.write		= write_nvram,
+	.unlocked_ioctl	= nvram_unlocked_ioctl,
+};
+
+static struct miscdevice nvram_dev = {
+	NVRAM_MINOR,
+	"nvram",
+	&nvram_fops
+};
+
+int __init nvram_init(void)
+{
+	int ret = 0;
+
+	printk(KERN_INFO "Generic non-volatile memory driver v%s\n",
+		NVRAM_VERSION);
+	ret = misc_register(&nvram_dev);
+	if (ret != 0)
+		goto out;
+
+	nvram_len = nvram_get_size();
+	if (nvram_len < 0)
+		nvram_len = NVRAM_SIZE;
+
+out:
+	return ret;
+}
+
+void __exit nvram_cleanup(void)
+{
+        misc_deregister( &nvram_dev );
+}
+
+module_init(nvram_init);
+module_exit(nvram_cleanup);
+MODULE_LICENSE("GPL");