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path: root/drivers/macintosh/nvram.c
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Diffstat (limited to 'drivers/macintosh/nvram.c')
-rw-r--r--drivers/macintosh/nvram.c131
1 files changed, 131 insertions, 0 deletions
diff --git a/drivers/macintosh/nvram.c b/drivers/macintosh/nvram.c
new file mode 100644
index 00000000000..30791875fc9
--- /dev/null
+++ b/drivers/macintosh/nvram.c
@@ -0,0 +1,131 @@
+/*
+ * /dev/nvram driver for Power Macintosh.
+ */
+
+#define NVRAM_VERSION "1.0"
+
+#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 <linux/smp_lock.h>
+#include <asm/uaccess.h>
+#include <asm/nvram.h>
+
+#define NVRAM_SIZE 8192
+
+static loff_t nvram_llseek(struct file *file, loff_t offset, int origin)
+{
+ lock_kernel();
+ switch (origin) {
+ case 1:
+ offset += file->f_pos;
+ break;
+ case 2:
+ offset += NVRAM_SIZE;
+ break;
+ }
+ if (offset < 0) {
+ unlock_kernel();
+ return -EINVAL;
+ }
+ file->f_pos = offset;
+ unlock_kernel();
+ return file->f_pos;
+}
+
+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_SIZE)
+ return 0;
+ for (i = *ppos; count > 0 && i < NVRAM_SIZE; ++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_SIZE)
+ return 0;
+ for (i = *ppos; count > 0 && i < NVRAM_SIZE; ++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 inode *inode, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ switch(cmd) {
+ case PMAC_NVRAM_GET_OFFSET:
+ {
+ int part, offset;
+ 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;
+ }
+
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+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)
+{
+ printk(KERN_INFO "Macintosh non-volatile memory driver v%s\n",
+ NVRAM_VERSION);
+ return misc_register(&nvram_dev);
+}
+
+void __exit nvram_cleanup(void)
+{
+ misc_deregister( &nvram_dev );
+}
+
+module_init(nvram_init);
+module_exit(nvram_cleanup);
+MODULE_LICENSE("GPL");