test: dm: add MDIO test

A very simple test for DM_MDIO, mimicks a register write/read through the
sandbox bus to a dummy PHY.

Signed-off-by: Alex Marginean <alexm.osslist@gmail.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>

1 files changed, 92 insertions, 0 deletions

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),
+};