3 files changed, 103 insertions, 0 deletions
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index 6fba5a84dd..635f8d72c2 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -24,6 +24,16 @@ config DM_MDIO
 	  This is currently implemented in net/mdio-uclass.c
 	  Look in include/miiphy.h for details.
 
+config MDIO_SANDBOX
+	depends on DM_MDIO && SANDBOX
+	default y
+	bool "Sandbox: Mocked MDIO driver"
+	help
+	  This driver implements dummy read/write/reset MDIO functions mimicking
+	  a bus with a single PHY.
+
+	  This driver is used in for testing in test/dm/mdio.c
+
 menuconfig NETDEVICES
 	bool "Network device support"
 	depends on NET
diff --git a/drivers/net/Makefile b/drivers/net/Makefile
index 8d02a37896..40038427db 100644
--- a/drivers/net/Makefile
+++ b/drivers/net/Makefile
@@ -77,3 +77,4 @@ obj-y += ti/
 obj-$(CONFIG_MEDIATEK_ETH) += mtk_eth.o
 obj-y += mscc_eswitch/
 obj-$(CONFIG_HIGMACV300_ETH) += higmacv300.o
+obj-$(CONFIG_MDIO_SANDBOX) += mdio_sandbox.o
diff --git a/drivers/net/mdio_sandbox.c b/drivers/net/mdio_sandbox.c
new file mode 100644
index 0000000000..07515e078c
--- /dev/null
+++ b/drivers/net/mdio_sandbox.c
@@ -0,0 +1,92 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2019
+ * Alex Marginean, NXP
+ */
+
+#include <dm.h>
+#include <errno.h>
+#include <miiphy.h>
+
+#define SANDBOX_PHY_ADDR	5
+#define SANDBOX_PHY_REG		0
+
+struct mdio_sandbox_priv {
+	int enabled;
+	u16 reg;
+};
+
+static int mdio_sandbox_read(struct udevice *dev, int addr, int devad, int reg)
+{
+	struct mdio_sandbox_priv *priv = dev_get_priv(dev);
+
+	if (!priv->enabled)
+		return -ENODEV;
+
+	if (addr != SANDBOX_PHY_ADDR)
+		return -ENODEV;
+	if (devad != MDIO_DEVAD_NONE)
+		return -ENODEV;
+	if (reg != SANDBOX_PHY_REG)
+		return -ENODEV;
+
+	return priv->reg;
+}
+
+static int mdio_sandbox_write(struct udevice *dev, int addr, int devad, int reg,
+			      u16 val)
+{
+	struct mdio_sandbox_priv *priv = dev_get_priv(dev);
+
+	if (!priv->enabled)
+		return -ENODEV;
+
+	if (addr != SANDBOX_PHY_ADDR)
+		return -ENODEV;
+	if (devad != MDIO_DEVAD_NONE)
+		return -ENODEV;
+	if (reg != SANDBOX_PHY_REG)
+		return -ENODEV;
+
+	priv->reg = val;
+
+	return 0;
+}
+
+static int mdio_sandbox_reset(struct udevice *dev)
+{
+	struct mdio_sandbox_priv *priv = dev_get_priv(dev);
+
+	priv->reg = 0;
+
+	return 0;
+}
+
+static const struct mdio_ops mdio_sandbox_ops = {
+	.read = mdio_sandbox_read,
+	.write = mdio_sandbox_write,
+	.reset = mdio_sandbox_reset,
+};
+
+static int mdio_sandbox_probe(struct udevice *dev)
+{
+	struct mdio_sandbox_priv *priv = dev_get_priv(dev);
+
+	priv->enabled = 1;
+
+	return 0;
+}
+
+static const struct udevice_id mdio_sandbox_ids[] = {
+	{ .compatible = "sandbox,mdio" },
+	{ }
+};
+
+U_BOOT_DRIVER(mdio_sandbox) = {
+	.name		= "mdio_sandbox",
+	.id		= UCLASS_MDIO,
+	.of_match	= mdio_sandbox_ids,
+	.probe		= mdio_sandbox_probe,
+	.ops		= &mdio_sandbox_ops,
+	.priv_auto_alloc_size = sizeof(struct mdio_sandbox_priv),
+};