1 files changed, 73 insertions, 0 deletions
diff --git a/drivers/misc/mem.c b/drivers/misc/mem.c
new file mode 100644
index 0000000000..6dd7f687c9
--- /dev/null
+++ b/drivers/misc/mem.c
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2011 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
+ */
+
+#include <common.h>
+#include <driver.h>
+#include <init.h>
+
+static struct cdev_operations memops = {
+	.read  = mem_read,
+	.write = mem_write,
+	.memmap = generic_memmap_rw,
+};
+
+static int mem_probe(struct device_d *dev)
+{
+	struct cdev *cdev;
+
+	cdev = xzalloc(sizeof (*cdev));
+	dev->priv = cdev;
+
+	cdev->name = (char*)dev->resource[0].name;
+	if (dev->resource[0].start == 0 && dev->resource[0].end == ~0) {
+		/*
+		 * Special case for /dev/mem. We can't express it's size as it's
+		 * outside of our address range. Set DEVFS_IS_CHARACTER_DEV to
+		 * bypass size checks.
+		 */
+		cdev->size = 0;
+		cdev->flags = DEVFS_IS_CHARACTER_DEV;
+	} else {
+		cdev->size = resource_size(&dev->resource[0]);
+	}
+
+	cdev->ops = &memops;
+	cdev->dev = dev;
+
+	devfs_create(cdev);
+
+	return 0;
+}
+
+static struct driver_d mem_drv = {
+	.name  = "mem",
+	.probe = mem_probe,
+};
+
+static int mem_init(void)
+{
+	struct device_d *dev;
+	struct resource res = {
+		.start = 0,
+		.end = ~0,
+		.flags = IORESOURCE_MEM,
+		.name = "mem",
+	};
+	int ret;
+
+	dev = device_alloc("mem", DEVICE_ID_DYNAMIC);
+	if (!dev)
+		return -ENOMEM;
+
+	dev->resource = xmemdup(&res, sizeof(res));
+	dev->num_resources = 1;
+
+	ret = platform_device_register(dev);
+	if (ret)
+		return ret;
+
+	return platform_driver_register(&mem_drv);
+}
+device_initcall(mem_init);