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path: root/drivers/net/mdio/mdio-bcm-unimac.c
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Diffstat (limited to 'drivers/net/mdio/mdio-bcm-unimac.c')
-rw-r--r--drivers/net/mdio/mdio-bcm-unimac.c363
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);