Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/net/phy/mdio-aspeed.c b/drivers/net/phy/mdio-aspeed.c
new file mode 100644
index 0000000..cad8205
--- /dev/null
+++ b/drivers/net/phy/mdio-aspeed.c
@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Copyright (C) 2019 IBM Corp. */
+
+#include <linux/bitfield.h>
+#include <linux/delay.h>
+#include <linux/iopoll.h>
+#include <linux/mdio.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_mdio.h>
+#include <linux/phy.h>
+#include <linux/platform_device.h>
+
+#define DRV_NAME "mdio-aspeed"
+
+#define ASPEED_MDIO_CTRL		0x0
+#define   ASPEED_MDIO_CTRL_FIRE		BIT(31)
+#define   ASPEED_MDIO_CTRL_ST		BIT(28)
+#define     ASPEED_MDIO_CTRL_ST_C45	0
+#define     ASPEED_MDIO_CTRL_ST_C22	1
+#define   ASPEED_MDIO_CTRL_OP		GENMASK(27, 26)
+#define     MDIO_C22_OP_WRITE		0b01
+#define     MDIO_C22_OP_READ		0b10
+#define   ASPEED_MDIO_CTRL_PHYAD	GENMASK(25, 21)
+#define   ASPEED_MDIO_CTRL_REGAD	GENMASK(20, 16)
+#define   ASPEED_MDIO_CTRL_MIIWDATA	GENMASK(15, 0)
+
+#define ASPEED_MDIO_DATA		0x4
+#define   ASPEED_MDIO_DATA_MDC_THRES	GENMASK(31, 24)
+#define   ASPEED_MDIO_DATA_MDIO_EDGE	BIT(23)
+#define   ASPEED_MDIO_DATA_MDIO_LATCH	GENMASK(22, 20)
+#define   ASPEED_MDIO_DATA_IDLE		BIT(16)
+#define   ASPEED_MDIO_DATA_MIIRDATA	GENMASK(15, 0)
+
+#define ASPEED_MDIO_INTERVAL_US		100
+#define ASPEED_MDIO_TIMEOUT_US		(ASPEED_MDIO_INTERVAL_US * 10)
+
+struct aspeed_mdio {
+	void __iomem *base;
+};
+
+static int aspeed_mdio_read(struct mii_bus *bus, int addr, int regnum)
+{
+	struct aspeed_mdio *ctx = bus->priv;
+	u32 ctrl;
+	u32 data;
+	int rc;
+
+	dev_dbg(&bus->dev, "%s: addr: %d, regnum: %d\n", __func__, addr,
+		regnum);
+
+	/* Just clause 22 for the moment */
+	if (regnum & MII_ADDR_C45)
+		return -EOPNOTSUPP;
+
+	ctrl = ASPEED_MDIO_CTRL_FIRE
+		| FIELD_PREP(ASPEED_MDIO_CTRL_ST, ASPEED_MDIO_CTRL_ST_C22)
+		| FIELD_PREP(ASPEED_MDIO_CTRL_OP, MDIO_C22_OP_READ)
+		| FIELD_PREP(ASPEED_MDIO_CTRL_PHYAD, addr)
+		| FIELD_PREP(ASPEED_MDIO_CTRL_REGAD, regnum);
+
+	iowrite32(ctrl, ctx->base + ASPEED_MDIO_CTRL);
+
+	rc = readl_poll_timeout(ctx->base + ASPEED_MDIO_DATA, data,
+				data & ASPEED_MDIO_DATA_IDLE,
+				ASPEED_MDIO_INTERVAL_US,
+				ASPEED_MDIO_TIMEOUT_US);
+	if (rc < 0)
+		return rc;
+
+	return FIELD_GET(ASPEED_MDIO_DATA_MIIRDATA, data);
+}
+
+static int aspeed_mdio_write(struct mii_bus *bus, int addr, int regnum, u16 val)
+{
+	struct aspeed_mdio *ctx = bus->priv;
+	u32 ctrl;
+
+	dev_dbg(&bus->dev, "%s: addr: %d, regnum: %d, val: 0x%x\n",
+		__func__, addr, regnum, val);
+
+	/* Just clause 22 for the moment */
+	if (regnum & MII_ADDR_C45)
+		return -EOPNOTSUPP;
+
+	ctrl = ASPEED_MDIO_CTRL_FIRE
+		| FIELD_PREP(ASPEED_MDIO_CTRL_ST, ASPEED_MDIO_CTRL_ST_C22)
+		| FIELD_PREP(ASPEED_MDIO_CTRL_OP, MDIO_C22_OP_WRITE)
+		| FIELD_PREP(ASPEED_MDIO_CTRL_PHYAD, addr)
+		| FIELD_PREP(ASPEED_MDIO_CTRL_REGAD, regnum)
+		| FIELD_PREP(ASPEED_MDIO_CTRL_MIIWDATA, val);
+
+	iowrite32(ctrl, ctx->base + ASPEED_MDIO_CTRL);
+
+	return readl_poll_timeout(ctx->base + ASPEED_MDIO_CTRL, ctrl,
+				  !(ctrl & ASPEED_MDIO_CTRL_FIRE),
+				  ASPEED_MDIO_INTERVAL_US,
+				  ASPEED_MDIO_TIMEOUT_US);
+}
+
+static int aspeed_mdio_probe(struct platform_device *pdev)
+{
+	struct aspeed_mdio *ctx;
+	struct mii_bus *bus;
+	int rc;
+
+	bus = devm_mdiobus_alloc_size(&pdev->dev, sizeof(*ctx));
+	if (!bus)
+		return -ENOMEM;
+
+	ctx = bus->priv;
+	ctx->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(ctx->base))
+		return PTR_ERR(ctx->base);
+
+	bus->name = DRV_NAME;
+	snprintf(bus->id, MII_BUS_ID_SIZE, "%s%d", pdev->name, pdev->id);
+	bus->parent = &pdev->dev;
+	bus->read = aspeed_mdio_read;
+	bus->write = aspeed_mdio_write;
+
+	rc = of_mdiobus_register(bus, pdev->dev.of_node);
+	if (rc) {
+		dev_err(&pdev->dev, "Cannot register MDIO bus!\n");
+		return rc;
+	}
+
+	platform_set_drvdata(pdev, bus);
+
+	return 0;
+}
+
+static int aspeed_mdio_remove(struct platform_device *pdev)
+{
+	mdiobus_unregister(platform_get_drvdata(pdev));
+
+	return 0;
+}
+
+static const struct of_device_id aspeed_mdio_of_match[] = {
+	{ .compatible = "aspeed,ast2600-mdio", },
+	{ },
+};
+
+static struct platform_driver aspeed_mdio_driver = {
+	.driver = {
+		.name = DRV_NAME,
+		.of_match_table = aspeed_mdio_of_match,
+	},
+	.probe = aspeed_mdio_probe,
+	.remove = aspeed_mdio_remove,
+};
+
+module_platform_driver(aspeed_mdio_driver);
+
+MODULE_AUTHOR("Andrew Jeffery <andrew@aj.id.au>");
+MODULE_LICENSE("GPL");