net: mdio: Move MDIO drivers into a new subdirectory

Move all the MDIO drivers and multiplexers into drivers/net/mdio.  The
mdio core is however left in the phy directory, due to mutual
dependencies between the MDIO core and the PHY core.

Take this opportunity to sort the Kconfig based on the menuconfig
strings, and move the multiplexers to the end with a separating
comment.

v2:
Fix typo in commit message

Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 363 insertions, 0 deletions

diff --git a/drivers/net/mdio/mdio-bcm-unimac.c b/drivers/net/mdio/mdio-bcm-unimac.c
new file mode 100644
index 000000000000..fbd36891ee64
--- /dev/null
+++ b/drivers/net/mdio/mdio-bcm-unimac.c
@@ -0,0 +1,363 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Broadcom UniMAC MDIO bus controller driver
+ *
+ * Copyright (C) 2014-2017 Broadcom
+ */
+
+#include <linux/kernel.h>
+#include <linux/phy.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <linux/clk.h>
+
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/of_mdio.h>
+
+#include <linux/platform_data/mdio-bcm-unimac.h>
+
+#define MDIO_CMD		0x00
+#define  MDIO_START_BUSY	(1 << 29)
+#define  MDIO_READ_FAIL		(1 << 28)
+#define  MDIO_RD		(2 << 26)
+#define  MDIO_WR		(1 << 26)
+#define  MDIO_PMD_SHIFT		21
+#define  MDIO_PMD_MASK		0x1F
+#define  MDIO_REG_SHIFT		16
+#define  MDIO_REG_MASK		0x1F
+
+#define MDIO_CFG		0x04
+#define  MDIO_C22		(1 << 0)
+#define  MDIO_C45		0
+#define  MDIO_CLK_DIV_SHIFT	4
+#define  MDIO_CLK_DIV_MASK	0x3F
+#define  MDIO_SUPP_PREAMBLE	(1 << 12)
+
+struct unimac_mdio_priv {
+	struct mii_bus		*mii_bus;
+	void __iomem		*base;
+	int (*wait_func)	(void *wait_func_data);
+	void			*wait_func_data;
+	struct clk		*clk;
+	u32			clk_freq;
+};
+
+static inline u32 unimac_mdio_readl(struct unimac_mdio_priv *priv, u32 offset)
+{
+	/* MIPS chips strapped for BE will automagically configure the
+	 * peripheral registers for CPU-native byte order.
+	 */
+	if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
+		return __raw_readl(priv->base + offset);
+	else
+		return readl_relaxed(priv->base + offset);
+}
+
+static inline void unimac_mdio_writel(struct unimac_mdio_priv *priv, u32 val,
+				      u32 offset)
+{
+	if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
+		__raw_writel(val, priv->base + offset);
+	else
+		writel_relaxed(val, priv->base + offset);
+}
+
+static inline void unimac_mdio_start(struct unimac_mdio_priv *priv)
+{
+	u32 reg;
+
+	reg = unimac_mdio_readl(priv, MDIO_CMD);
+	reg |= MDIO_START_BUSY;
+	unimac_mdio_writel(priv, reg, MDIO_CMD);
+}
+
+static inline unsigned int unimac_mdio_busy(struct unimac_mdio_priv *priv)
+{
+	return unimac_mdio_readl(priv, MDIO_CMD) & MDIO_START_BUSY;
+}
+
+static int unimac_mdio_poll(void *wait_func_data)
+{
+	struct unimac_mdio_priv *priv = wait_func_data;
+	unsigned int timeout = 1000;
+
+	do {
+		if (!unimac_mdio_busy(priv))
+			return 0;
+
+		usleep_range(1000, 2000);
+	} while (--timeout);
+
+	return -ETIMEDOUT;
+}
+
+static int unimac_mdio_read(struct mii_bus *bus, int phy_id, int reg)
+{
+	struct unimac_mdio_priv *priv = bus->priv;
+	int ret;
+	u32 cmd;
+
+	/* Prepare the read operation */
+	cmd = MDIO_RD | (phy_id << MDIO_PMD_SHIFT) | (reg << MDIO_REG_SHIFT);
+	unimac_mdio_writel(priv, cmd, MDIO_CMD);
+
+	/* Start MDIO transaction */
+	unimac_mdio_start(priv);
+
+	ret = priv->wait_func(priv->wait_func_data);
+	if (ret)
+		return ret;
+
+	cmd = unimac_mdio_readl(priv, MDIO_CMD);
+
+	/* Some broken devices are known not to release the line during
+	 * turn-around, e.g: Broadcom BCM53125 external switches, so check for
+	 * that condition here and ignore the MDIO controller read failure
+	 * indication.
+	 */
+	if (!(bus->phy_ignore_ta_mask & 1 << phy_id) && (cmd & MDIO_READ_FAIL))
+		return -EIO;
+
+	return cmd & 0xffff;
+}
+
+static int unimac_mdio_write(struct mii_bus *bus, int phy_id,
+			     int reg, u16 val)
+{
+	struct unimac_mdio_priv *priv = bus->priv;
+	u32 cmd;
+
+	/* Prepare the write operation */
+	cmd = MDIO_WR | (phy_id << MDIO_PMD_SHIFT) |
+		(reg << MDIO_REG_SHIFT) | (0xffff & val);
+	unimac_mdio_writel(priv, cmd, MDIO_CMD);
+
+	unimac_mdio_start(priv);
+
+	return priv->wait_func(priv->wait_func_data);
+}
+
+/* Workaround for integrated BCM7xxx Gigabit PHYs which have a problem with
+ * their internal MDIO management controller making them fail to successfully
+ * be read from or written to for the first transaction.  We insert a dummy
+ * BMSR read here to make sure that phy_get_device() and get_phy_id() can
+ * correctly read the PHY MII_PHYSID1/2 registers and successfully register a
+ * PHY device for this peripheral.
+ *
+ * Once the PHY driver is registered, we can workaround subsequent reads from
+ * there (e.g: during system-wide power management).
+ *
+ * bus->reset is invoked before mdiobus_scan during mdiobus_register and is
+ * therefore the right location to stick that workaround. Since we do not want
+ * to read from non-existing PHYs, we either use bus->phy_mask or do a manual
+ * Device Tree scan to limit the search area.
+ */
+static int unimac_mdio_reset(struct mii_bus *bus)
+{
+	struct device_node *np = bus->dev.of_node;
+	struct device_node *child;
+	u32 read_mask = 0;
+	int addr;
+
+	if (!np) {
+		read_mask = ~bus->phy_mask;
+	} else {
+		for_each_available_child_of_node(np, child) {
+			addr = of_mdio_parse_addr(&bus->dev, child);
+			if (addr < 0)
+				continue;
+
+			read_mask |= 1 << addr;
+		}
+	}
+
+	for (addr = 0; addr < PHY_MAX_ADDR; addr++) {
+		if (read_mask & 1 << addr) {
+			dev_dbg(&bus->dev, "Workaround for PHY @ %d\n", addr);
+			mdiobus_read(bus, addr, MII_BMSR);
+		}
+	}
+
+	return 0;
+}
+
+static void unimac_mdio_clk_set(struct unimac_mdio_priv *priv)
+{
+	unsigned long rate;
+	u32 reg, div;
+
+	/* Keep the hardware default values */
+	if (!priv->clk_freq)
+		return;
+
+	if (!priv->clk)
+		rate = 250000000;
+	else
+		rate = clk_get_rate(priv->clk);
+
+	div = (rate / (2 * priv->clk_freq)) - 1;
+	if (div & ~MDIO_CLK_DIV_MASK) {
+		pr_warn("Incorrect MDIO clock frequency, ignoring\n");
+		return;
+	}
+
+	/* The MDIO clock is the reference clock (typicaly 250Mhz) divided by
+	 * 2 x (MDIO_CLK_DIV + 1)
+	 */
+	reg = unimac_mdio_readl(priv, MDIO_CFG);
+	reg &= ~(MDIO_CLK_DIV_MASK << MDIO_CLK_DIV_SHIFT);
+	reg |= div << MDIO_CLK_DIV_SHIFT;
+	unimac_mdio_writel(priv, reg, MDIO_CFG);
+}
+
+static int unimac_mdio_probe(struct platform_device *pdev)
+{
+	struct unimac_mdio_pdata *pdata = pdev->dev.platform_data;
+	struct unimac_mdio_priv *priv;
+	struct device_node *np;
+	struct mii_bus *bus;
+	struct resource *r;
+	int ret;
+
+	np = pdev->dev.of_node;
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!r)
+		return -EINVAL;
+
+	/* Just ioremap, as this MDIO block is usually integrated into an
+	 * Ethernet MAC controller register range
+	 */
+	priv->base = devm_ioremap(&pdev->dev, r->start, resource_size(r));
+	if (!priv->base) {
+		dev_err(&pdev->dev, "failed to remap register\n");
+		return -ENOMEM;
+	}
+
+	priv->clk = devm_clk_get_optional(&pdev->dev, NULL);
+	if (IS_ERR(priv->clk))
+		return PTR_ERR(priv->clk);
+
+	ret = clk_prepare_enable(priv->clk);
+	if (ret)
+		return ret;
+
+	if (of_property_read_u32(np, "clock-frequency", &priv->clk_freq))
+		priv->clk_freq = 0;
+
+	unimac_mdio_clk_set(priv);
+
+	priv->mii_bus = mdiobus_alloc();
+	if (!priv->mii_bus) {
+		ret = -ENOMEM;
+		goto out_clk_disable;
+	}
+
+	bus = priv->mii_bus;
+	bus->priv = priv;
+	if (pdata) {
+		bus->name = pdata->bus_name;
+		priv->wait_func = pdata->wait_func;
+		priv->wait_func_data = pdata->wait_func_data;
+		bus->phy_mask = ~pdata->phy_mask;
+	} else {
+		bus->name = "unimac MII bus";
+		priv->wait_func_data = priv;
+		priv->wait_func = unimac_mdio_poll;
+	}
+	bus->parent = &pdev->dev;
+	bus->read = unimac_mdio_read;
+	bus->write = unimac_mdio_write;
+	bus->reset = unimac_mdio_reset;
+	snprintf(bus->id, MII_BUS_ID_SIZE, "%s-%d", pdev->name, pdev->id);
+
+	ret = of_mdiobus_register(bus, np);
+	if (ret) {
+		dev_err(&pdev->dev, "MDIO bus registration failed\n");
+		goto out_mdio_free;
+	}
+
+	platform_set_drvdata(pdev, priv);
+
+	dev_info(&pdev->dev, "Broadcom UniMAC MDIO bus\n");
+
+	return 0;
+
+out_mdio_free:
+	mdiobus_free(bus);
+out_clk_disable:
+	clk_disable_unprepare(priv->clk);
+	return ret;
+}
+
+static int unimac_mdio_remove(struct platform_device *pdev)
+{
+	struct unimac_mdio_priv *priv = platform_get_drvdata(pdev);
+
+	mdiobus_unregister(priv->mii_bus);
+	mdiobus_free(priv->mii_bus);
+	clk_disable_unprepare(priv->clk);
+
+	return 0;
+}
+
+static int __maybe_unused unimac_mdio_suspend(struct device *d)
+{
+	struct unimac_mdio_priv *priv = dev_get_drvdata(d);
+
+	clk_disable_unprepare(priv->clk);
+
+	return 0;
+}
+
+static int __maybe_unused unimac_mdio_resume(struct device *d)
+{
+	struct unimac_mdio_priv *priv = dev_get_drvdata(d);
+	int ret;
+
+	ret = clk_prepare_enable(priv->clk);
+	if (ret)
+		return ret;
+
+	unimac_mdio_clk_set(priv);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(unimac_mdio_pm_ops,
+			 unimac_mdio_suspend, unimac_mdio_resume);
+
+static const struct of_device_id unimac_mdio_ids[] = {
+	{ .compatible = "brcm,genet-mdio-v5", },
+	{ .compatible = "brcm,genet-mdio-v4", },
+	{ .compatible = "brcm,genet-mdio-v3", },
+	{ .compatible = "brcm,genet-mdio-v2", },
+	{ .compatible = "brcm,genet-mdio-v1", },
+	{ .compatible = "brcm,unimac-mdio", },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, unimac_mdio_ids);
+
+static struct platform_driver unimac_mdio_driver = {
+	.driver = {
+		.name = UNIMAC_MDIO_DRV_NAME,
+		.of_match_table = unimac_mdio_ids,
+		.pm = &unimac_mdio_pm_ops,
+	},
+	.probe	= unimac_mdio_probe,
+	.remove	= unimac_mdio_remove,
+};
+module_platform_driver(unimac_mdio_driver);
+
+MODULE_AUTHOR("Broadcom Corporation");
+MODULE_DESCRIPTION("Broadcom UniMAC MDIO bus controller");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" UNIMAC_MDIO_DRV_NAME);