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path: root/drivers/net/mdio/mdio-mscc-miim.c
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Diffstat (limited to 'drivers/net/mdio/mdio-mscc-miim.c')
-rw-r--r--drivers/net/mdio/mdio-mscc-miim.c212
1 files changed, 212 insertions, 0 deletions
diff --git a/drivers/net/mdio/mdio-mscc-miim.c b/drivers/net/mdio/mdio-mscc-miim.c
new file mode 100644
index 000000000000..11f583fd4611
--- /dev/null
+++ b/drivers/net/mdio/mdio-mscc-miim.c
@@ -0,0 +1,212 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+/*
+ * Driver for the MDIO interface of Microsemi network switches.
+ *
+ * Author: Alexandre Belloni <alexandre.belloni@bootlin.com>
+ * Copyright (c) 2017 Microsemi Corporation
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/phy.h>
+#include <linux/platform_device.h>
+#include <linux/bitops.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/of_mdio.h>
+
+#define MSCC_MIIM_REG_STATUS 0x0
+#define MSCC_MIIM_STATUS_STAT_PENDING BIT(2)
+#define MSCC_MIIM_STATUS_STAT_BUSY BIT(3)
+#define MSCC_MIIM_REG_CMD 0x8
+#define MSCC_MIIM_CMD_OPR_WRITE BIT(1)
+#define MSCC_MIIM_CMD_OPR_READ BIT(2)
+#define MSCC_MIIM_CMD_WRDATA_SHIFT 4
+#define MSCC_MIIM_CMD_REGAD_SHIFT 20
+#define MSCC_MIIM_CMD_PHYAD_SHIFT 25
+#define MSCC_MIIM_CMD_VLD BIT(31)
+#define MSCC_MIIM_REG_DATA 0xC
+#define MSCC_MIIM_DATA_ERROR (BIT(16) | BIT(17))
+
+#define MSCC_PHY_REG_PHY_CFG 0x0
+#define PHY_CFG_PHY_ENA (BIT(0) | BIT(1) | BIT(2) | BIT(3))
+#define PHY_CFG_PHY_COMMON_RESET BIT(4)
+#define PHY_CFG_PHY_RESET (BIT(5) | BIT(6) | BIT(7) | BIT(8))
+#define MSCC_PHY_REG_PHY_STATUS 0x4
+
+struct mscc_miim_dev {
+ void __iomem *regs;
+ void __iomem *phy_regs;
+};
+
+/* When high resolution timers aren't built-in: we can't use usleep_range() as
+ * we would sleep way too long. Use udelay() instead.
+ */
+#define mscc_readl_poll_timeout(addr, val, cond, delay_us, timeout_us) \
+({ \
+ if (!IS_ENABLED(CONFIG_HIGH_RES_TIMERS)) \
+ readl_poll_timeout_atomic(addr, val, cond, delay_us, \
+ timeout_us); \
+ readl_poll_timeout(addr, val, cond, delay_us, timeout_us); \
+})
+
+static int mscc_miim_wait_ready(struct mii_bus *bus)
+{
+ struct mscc_miim_dev *miim = bus->priv;
+ u32 val;
+
+ return mscc_readl_poll_timeout(miim->regs + MSCC_MIIM_REG_STATUS, val,
+ !(val & MSCC_MIIM_STATUS_STAT_BUSY), 50,
+ 10000);
+}
+
+static int mscc_miim_wait_pending(struct mii_bus *bus)
+{
+ struct mscc_miim_dev *miim = bus->priv;
+ u32 val;
+
+ return mscc_readl_poll_timeout(miim->regs + MSCC_MIIM_REG_STATUS, val,
+ !(val & MSCC_MIIM_STATUS_STAT_PENDING),
+ 50, 10000);
+}
+
+static int mscc_miim_read(struct mii_bus *bus, int mii_id, int regnum)
+{
+ struct mscc_miim_dev *miim = bus->priv;
+ u32 val;
+ int ret;
+
+ ret = mscc_miim_wait_pending(bus);
+ if (ret)
+ goto out;
+
+ writel(MSCC_MIIM_CMD_VLD | (mii_id << MSCC_MIIM_CMD_PHYAD_SHIFT) |
+ (regnum << MSCC_MIIM_CMD_REGAD_SHIFT) | MSCC_MIIM_CMD_OPR_READ,
+ miim->regs + MSCC_MIIM_REG_CMD);
+
+ ret = mscc_miim_wait_ready(bus);
+ if (ret)
+ goto out;
+
+ val = readl(miim->regs + MSCC_MIIM_REG_DATA);
+ if (val & MSCC_MIIM_DATA_ERROR) {
+ ret = -EIO;
+ goto out;
+ }
+
+ ret = val & 0xFFFF;
+out:
+ return ret;
+}
+
+static int mscc_miim_write(struct mii_bus *bus, int mii_id,
+ int regnum, u16 value)
+{
+ struct mscc_miim_dev *miim = bus->priv;
+ int ret;
+
+ ret = mscc_miim_wait_pending(bus);
+ if (ret < 0)
+ goto out;
+
+ writel(MSCC_MIIM_CMD_VLD | (mii_id << MSCC_MIIM_CMD_PHYAD_SHIFT) |
+ (regnum << MSCC_MIIM_CMD_REGAD_SHIFT) |
+ (value << MSCC_MIIM_CMD_WRDATA_SHIFT) |
+ MSCC_MIIM_CMD_OPR_WRITE,
+ miim->regs + MSCC_MIIM_REG_CMD);
+
+out:
+ return ret;
+}
+
+static int mscc_miim_reset(struct mii_bus *bus)
+{
+ struct mscc_miim_dev *miim = bus->priv;
+
+ if (miim->phy_regs) {
+ writel(0, miim->phy_regs + MSCC_PHY_REG_PHY_CFG);
+ writel(0x1ff, miim->phy_regs + MSCC_PHY_REG_PHY_CFG);
+ mdelay(500);
+ }
+
+ return 0;
+}
+
+static int mscc_miim_probe(struct platform_device *pdev)
+{
+ struct resource *res;
+ struct mii_bus *bus;
+ struct mscc_miim_dev *dev;
+ int ret;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ return -ENODEV;
+
+ bus = devm_mdiobus_alloc_size(&pdev->dev, sizeof(*dev));
+ if (!bus)
+ return -ENOMEM;
+
+ bus->name = "mscc_miim";
+ bus->read = mscc_miim_read;
+ bus->write = mscc_miim_write;
+ bus->reset = mscc_miim_reset;
+ snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(&pdev->dev));
+ bus->parent = &pdev->dev;
+
+ dev = bus->priv;
+ dev->regs = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(dev->regs)) {
+ dev_err(&pdev->dev, "Unable to map MIIM registers\n");
+ return PTR_ERR(dev->regs);
+ }
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+ if (res) {
+ dev->phy_regs = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(dev->phy_regs)) {
+ dev_err(&pdev->dev, "Unable to map internal phy registers\n");
+ return PTR_ERR(dev->phy_regs);
+ }
+ }
+
+ ret = of_mdiobus_register(bus, pdev->dev.of_node);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Cannot register MDIO bus (%d)\n", ret);
+ return ret;
+ }
+
+ platform_set_drvdata(pdev, bus);
+
+ return 0;
+}
+
+static int mscc_miim_remove(struct platform_device *pdev)
+{
+ struct mii_bus *bus = platform_get_drvdata(pdev);
+
+ mdiobus_unregister(bus);
+
+ return 0;
+}
+
+static const struct of_device_id mscc_miim_match[] = {
+ { .compatible = "mscc,ocelot-miim" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, mscc_miim_match);
+
+static struct platform_driver mscc_miim_driver = {
+ .probe = mscc_miim_probe,
+ .remove = mscc_miim_remove,
+ .driver = {
+ .name = "mscc-miim",
+ .of_match_table = mscc_miim_match,
+ },
+};
+
+module_platform_driver(mscc_miim_driver);
+
+MODULE_DESCRIPTION("Microsemi MIIM driver");
+MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
+MODULE_LICENSE("Dual MIT/GPL");