drivers: smem: sandbox

Add Sandbox driver for SMEM. mostly stub operations.

Signed-off-by: Ramon Fried <ramon.fried@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/smem/Kconfig b/drivers/smem/Kconfig
index 6cf5a4e..7169d0f 100644
--- a/drivers/smem/Kconfig
+++ b/drivers/smem/Kconfig
@@ -3,6 +3,15 @@
 
 if SMEM
 
+config SANDBOX_SMEM
+    bool "Sandbox Shared Memory Manager (SMEM)"
+    depends on SANDBOX && DM
+    help
+      enable SMEM support for sandbox. This is an emulation of a real SMEM
+      manager.
+      The sandbox driver allocates a shared memory from the heap and
+      initialzies it on start.
+
 config MSM_SMEM
     bool "Qualcomm Shared Memory Manager (SMEM)"
     depends on DM
diff --git a/drivers/smem/Makefile b/drivers/smem/Makefile
index 605b8fc..af3e9b5 100644
--- a/drivers/smem/Makefile
+++ b/drivers/smem/Makefile
@@ -2,5 +2,6 @@
 #
 # Makefile for the U-Boot SMEM interface drivers
 
+obj-$(CONFIG_SANDBOX_SMEM) += sandbox_smem.o
 obj-$(CONFIG_SMEM) += smem-uclass.o
 obj-$(CONFIG_MSM_SMEM) += msm_smem.o
diff --git a/drivers/smem/sandbox_smem.c b/drivers/smem/sandbox_smem.c
new file mode 100644
index 0000000..7397e44
--- /dev/null
+++ b/drivers/smem/sandbox_smem.c
@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2018 Ramon Fried <ramon.fried@gmail.com>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <smem.h>
+#include <asm/test.h>
+
+static int sandbox_smem_alloc(unsigned int host,
+		unsigned int item, size_t size)
+{
+	return 0;
+}
+
+static void *sandbox_smem_get(unsigned int host,
+		unsigned int item, size_t *size)
+{
+	return NULL;
+}
+
+static int sandbox_smem_get_free_space(unsigned int host)
+{
+	return 0;
+}
+
+static const struct smem_ops sandbox_smem_ops = {
+	.alloc	= sandbox_smem_alloc,
+	.get	= sandbox_smem_get,
+	.get_free_space	= sandbox_smem_get_free_space,
+};
+
+static const struct udevice_id sandbox_smem_ids[] = {
+	{ .compatible = "sandbox,smem" },
+	{ }
+};
+
+U_BOOT_DRIVER(smem_sandbox) = {
+	.name		= "smem_sandbox",
+	.id		= UCLASS_SMEM,
+	.of_match	= sandbox_smem_ids,
+	.ops		= &sandbox_smem_ops,
+};