test: dm: add a test for MDIO MUX DM uclass

Adds a test using a makeshift MDIO MUX.  The test is based on the existing
MDIO test.  It uses the last emulated PHY register to verify MUX selection.

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

3 files changed, 108 insertions, 0 deletions

diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index 0dc26ac254..403df5e960 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -46,6 +46,16 @@ config MDIO_SANDBOX
 
 	  This driver is used in for testing in test/dm/mdio.c
 
+config MDIO_MUX_SANDBOX
+	depends on DM_MDIO_MUX && MDIO_SANDBOX
+	default y
+	bool "Sandbox: Mocked MDIO-MUX driver"
+	help
+	  This driver implements dummy select/deselect ops mimicking a MUX on
+	  the MDIO bux.  It uses mdio_sandbox driver as parent MDIO.
+
+	  This driver is used 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 40038427db..3c473b205d 100644
--- a/drivers/net/Makefile
+++ b/drivers/net/Makefile
@@ -37,6 +37,7 @@ obj-$(CONFIG_LAN91C96) += lan91c96.o
 obj-$(CONFIG_LPC32XX_ETH) += lpc32xx_eth.o
 obj-$(CONFIG_MACB) += macb.o
 obj-$(CONFIG_MCFFEC) += mcffec.o mcfmii.o
+obj-$(CONFIG_MDIO_MUX_SANDBOX) += mdio_mux_sandbox.o
 obj-$(CONFIG_MPC8XX_FEC) += mpc8xx_fec.o
 obj-$(CONFIG_MT7628_ETH) += mt7628-eth.o
 obj-$(CONFIG_MVGBE) += mvgbe.o
diff --git a/drivers/net/mdio_mux_sandbox.c b/drivers/net/mdio_mux_sandbox.c
new file mode 100644
index 0000000000..3dba4d18a1
--- /dev/null
+++ b/drivers/net/mdio_mux_sandbox.c
@@ -0,0 +1,97 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2019
+ * Alex Marginean, NXP
+ */
+
+#include <dm.h>
+#include <errno.h>
+#include <miiphy.h>
+
+/* macros copied over from mdio_sandbox.c */
+#define SANDBOX_PHY_ADDR	5
+#define SANDBOX_PHY_REG_CNT	2
+
+struct mdio_mux_sandbox_priv {
+	int enabled;
+	int sel;
+};
+
+static int mdio_mux_sandbox_mark_selection(struct udevice *dev, int sel)
+{
+	struct udevice *mdio;
+	struct mdio_ops *ops;
+	int err;
+
+	/*
+	 * find the sandbox parent mdio and write a register on the PHY there
+	 * so the mux test can verify selection.
+	 */
+	err = uclass_get_device_by_name(UCLASS_MDIO, "mdio-test", &mdio);
+	if (err)
+		return err;
+	ops = mdio_get_ops(mdio);
+	return ops->write(mdio, SANDBOX_PHY_ADDR, MDIO_DEVAD_NONE,
+			  SANDBOX_PHY_REG_CNT - 1, (u16)sel);
+}
+
+static int mdio_mux_sandbox_select(struct udevice *dev, int cur, int sel)
+{
+	struct mdio_mux_sandbox_priv *priv = dev_get_priv(dev);
+
+	if (!priv->enabled)
+		return -ENODEV;
+
+	if (cur != priv->sel)
+		return -EINVAL;
+
+	priv->sel = sel;
+	mdio_mux_sandbox_mark_selection(dev, priv->sel);
+
+	return 0;
+}
+
+static int mdio_mux_sandbox_deselect(struct udevice *dev, int sel)
+{
+	struct mdio_mux_sandbox_priv *priv = dev_get_priv(dev);
+
+	if (!priv->enabled)
+		return -ENODEV;
+
+	if (sel != priv->sel)
+		return -EINVAL;
+
+	priv->sel = -1;
+	mdio_mux_sandbox_mark_selection(dev, priv->sel);
+
+	return 0;
+}
+
+static const struct mdio_mux_ops mdio_mux_sandbox_ops = {
+	.select = mdio_mux_sandbox_select,
+	.deselect = mdio_mux_sandbox_deselect,
+};
+
+static int mdio_mux_sandbox_probe(struct udevice *dev)
+{
+	struct mdio_mux_sandbox_priv *priv = dev_get_priv(dev);
+
+	priv->enabled = 1;
+	priv->sel = -1;
+
+	return 0;
+}
+
+static const struct udevice_id mdio_mux_sandbox_ids[] = {
+	{ .compatible = "sandbox,mdio-mux" },
+	{ }
+};
+
+U_BOOT_DRIVER(mdio_mux_sandbox) = {
+	.name		= "mdio_mux_sandbox",
+	.id		= UCLASS_MDIO_MUX,
+	.of_match	= mdio_mux_sandbox_ids,
+	.probe		= mdio_mux_sandbox_probe,
+	.ops		= &mdio_mux_sandbox_ops,
+	.priv_auto_alloc_size = sizeof(struct mdio_mux_sandbox_priv),
+};