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>

arch/Kconfig

@@ -123,6 +123,8 @@ config SANDBOX
 	imply DM_SOUND
 	imply PCI_SANDBOX_EP
 	imply PCH
+	imply PHYLIB
+	imply DM_MDIO
 
 config SH
 	bool "SuperH architecture"

arch/sandbox/dts/test.dts

@@ -823,6 +823,10 @@
 		dmas = <&dma 0>, <&dma 1>, <&dma 2>;
 		dma-names = "m2m", "tx0", "rx0";
 	};
+
+	mdio-test {
+		compatible = "sandbox,mdio";
+	};
 };
 
 #include "sandbox_pmic.dtsi"

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

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

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),
+};

test/dm/Makefile

@@ -62,4 +62,5 @@ obj-$(CONFIG_SOUND) += sound.o
 obj-$(CONFIG_TEE) += tee.o
 obj-$(CONFIG_VIRTIO_SANDBOX) += virtio.o
 obj-$(CONFIG_DMA) += dma.o
+obj-$(CONFIG_DM_MDIO) += mdio.o
 endif

test/dm/mdio.c

@@ -0,0 +1,53 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2019
+ * Alex Marginean, NXP
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <dm/test.h>
+#include <misc.h>
+#include <test/ut.h>
+#include <miiphy.h>
+
+/* macros copied over from mdio_sandbox.c */
+#define SANDBOX_PHY_ADDR	5
+#define SANDBOX_PHY_REG		0
+
+#define TEST_REG_VALUE		0xabcd
+
+static int dm_test_mdio(struct unit_test_state *uts)
+{
+	struct uclass *uc;
+	struct udevice *dev;
+	struct mdio_ops *ops;
+	u16 reg;
+
+	ut_assertok(uclass_get(UCLASS_MDIO, &uc));
+
+	ut_assertok(uclass_get_device_by_name(UCLASS_MDIO, "mdio-test", &dev));
+
+	ops = mdio_get_ops(dev);
+	ut_assertnonnull(ops);
+	ut_assertnonnull(ops->read);
+	ut_assertnonnull(ops->write);
+
+	ut_assertok(ops->write(dev, SANDBOX_PHY_ADDR, MDIO_DEVAD_NONE,
+			       SANDBOX_PHY_REG, TEST_REG_VALUE));
+	reg = ops->read(dev, SANDBOX_PHY_ADDR, MDIO_DEVAD_NONE,
+			SANDBOX_PHY_REG);
+	ut_asserteq(reg, TEST_REG_VALUE);
+
+	ut_assert(ops->read(dev, SANDBOX_PHY_ADDR + 1, MDIO_DEVAD_NONE,
+			    SANDBOX_PHY_REG) != 0);
+
+	ut_assertok(ops->reset(dev));
+	reg = ops->read(dev, SANDBOX_PHY_ADDR, MDIO_DEVAD_NONE,
+			SANDBOX_PHY_REG);
+	ut_asserteq(reg, 0);
+
+	return 0;
+}
+
+DM_TEST(dm_test_mdio, DM_TESTF_SCAN_FDT);