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);