--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/devices/ccat/sram.c	Tue Oct 13 12:24:16 2015 +0200
@@ -0,0 +1,108 @@
+/**
+    Network Driver for Beckhoff CCAT communication controller
+    Copyright (C) 2015  Beckhoff Automation GmbH & Co. KG
+    Author: Patrick Bruenn <p.bruenn@beckhoff.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 of the License, 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.,
+    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include "module.h"
+#include <asm/io.h>
+#include <linux/fs.h>
+#include <linux/module.h>
+#include <linux/uaccess.h>
+
+#define CCAT_SRAM_DEVICES_MAX 4
+
+static ssize_t __sram_read(struct cdev_buffer *buffer, char __user * buf,
+			   size_t len, loff_t * off)
+{
+	memcpy_fromio(buffer->data, buffer->ccdev->ioaddr + *off, len);
+	if (copy_to_user(buf, buffer->data, len))
+		return -EFAULT;
+
+	*off += len;
+	return len;
+}
+
+static ssize_t ccat_sram_read(struct file *const f, char __user * buf,
+			      size_t len, loff_t * off)
+{
+	struct cdev_buffer *buffer = f->private_data;
+	const size_t iosize = buffer->ccdev->iosize;
+
+	if (*off >= iosize) {
+		return 0;
+	}
+
+	len = min(len, (size_t) (iosize - *off));
+
+	return __sram_read(buffer, buf, len, off);
+}
+
+static ssize_t ccat_sram_write(struct file *const f, const char __user * buf,
+			       size_t len, loff_t * off)
+{
+	struct cdev_buffer *const buffer = f->private_data;
+
+	if (*off + len > buffer->ccdev->iosize) {
+		return 0;
+	}
+
+	if (copy_from_user(buffer->data, buf, len)) {
+		return -EFAULT;
+	}
+
+	memcpy_toio(buffer->ccdev->ioaddr + *off, buffer->data, len);
+
+	*off += len;
+	return len;
+}
+
+static struct ccat_cdev dev_table[CCAT_SRAM_DEVICES_MAX];
+static struct ccat_class cdev_class = {
+	.instances = {0},
+	.count = CCAT_SRAM_DEVICES_MAX,
+	.devices = dev_table,
+	.name = "ccat_sram",
+	.fops = {
+		 .owner = THIS_MODULE,
+		 .open = ccat_cdev_open,
+		 .release = ccat_cdev_release,
+		 .read = ccat_sram_read,
+		 .write = ccat_sram_write,
+		 },
+};
+
+static int ccat_sram_probe(struct ccat_function *func)
+{
+	static const u8 NO_SRAM_CONNECTED = 0;
+	const u8 type = func->info.sram_width & 0x3;
+	const size_t iosize = (1 << func->info.sram_size);
+
+	pr_info("%s: 0x%04x rev: 0x%04x\n", __FUNCTION__, func->info.type,
+		func->info.rev);
+	if (type == NO_SRAM_CONNECTED) {
+		return -ENODEV;
+	}
+	return ccat_cdev_probe(func, &cdev_class, iosize);
+}
+
+struct ccat_driver sram_driver = {
+	.type = CCATINFO_SRAM,
+	.probe = ccat_sram_probe,
+	.remove = ccat_cdev_remove,
+	.cdev_class = &cdev_class,
+};