1 files changed, 118 insertions, 0 deletions

diff --git a/arch/powerpc/sysdev/mmio_nvram.c b/arch/powerpc/sysdev/mmio_nvram.c
new file mode 100644
index 000000000000..74e0d31a3559
--- /dev/null
+++ b/arch/powerpc/sysdev/mmio_nvram.c
@@ -0,0 +1,118 @@
+/*
+ * memory mapped NVRAM
+ *
+ * (C) Copyright IBM Corp. 2005
+ *
+ * Authors : Utz Bacher <utz.bacher@de.ibm.com>
+ *
+ * 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, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+#include <asm/machdep.h>
+#include <asm/nvram.h>
+#include <asm/prom.h>
+
+static void __iomem *mmio_nvram_start;
+static long mmio_nvram_len;
+static spinlock_t mmio_nvram_lock = SPIN_LOCK_UNLOCKED;
+
+static ssize_t mmio_nvram_read(char *buf, size_t count, loff_t *index)
+{
+        unsigned long flags;
+
+        if (*index >= mmio_nvram_len)
+                return 0;
+        if (*index + count > mmio_nvram_len)
+                count = mmio_nvram_len - *index;
+
+        spin_lock_irqsave(&mmio_nvram_lock, flags);
+
+        memcpy_fromio(buf, mmio_nvram_start + *index, count);
+
+        spin_unlock_irqrestore(&mmio_nvram_lock, flags);
+        
+        *index += count;
+        return count;
+}
+
+static ssize_t mmio_nvram_write(char *buf, size_t count, loff_t *index)
+{
+        unsigned long flags;
+
+        if (*index >= mmio_nvram_len)
+                return 0;
+        if (*index + count > mmio_nvram_len)
+                count = mmio_nvram_len - *index;
+
+        spin_lock_irqsave(&mmio_nvram_lock, flags);
+
+        memcpy_toio(mmio_nvram_start + *index, buf, count);
+
+        spin_unlock_irqrestore(&mmio_nvram_lock, flags);
+        
+        *index += count;
+        return count;
+}
+
+static ssize_t mmio_nvram_get_size(void)
+{
+        return mmio_nvram_len;
+}
+
+int __init mmio_nvram_init(void)
+{
+        struct device_node *nvram_node;
+        unsigned long *buffer;
+        int proplen;
+        unsigned long nvram_addr;
+        int ret;
+
+        ret = -ENODEV;
+        nvram_node = of_find_node_by_type(NULL, "nvram");
+        if (!nvram_node)
+                goto out;
+
+        ret = -EIO;
+        buffer = (unsigned long *)get_property(nvram_node, "reg", &proplen);
+        if (proplen != 2*sizeof(unsigned long))
+                goto out;
+
+        ret = -ENODEV;
+        nvram_addr = buffer[0];
+        mmio_nvram_len = buffer[1];
+        if ( (!mmio_nvram_len) || (!nvram_addr) )
+                goto out;
+
+        mmio_nvram_start = ioremap(nvram_addr, mmio_nvram_len);
+        if (!mmio_nvram_start)
+                goto out;
+
+        printk(KERN_INFO "mmio NVRAM, %luk mapped to %p\n",
+               mmio_nvram_len >> 10, mmio_nvram_start);
+
+        ppc_md.nvram_read       = mmio_nvram_read;
+        ppc_md.nvram_write      = mmio_nvram_write;
+        ppc_md.nvram_size       = mmio_nvram_get_size;
+
+out:
+        of_node_put(nvram_node);
+        return ret;
+}