net: mdio: Add BCM6368 MDIO mux bus controller

This controller is present on BCM6318, BCM6328, BCM6362, BCM6368 and BCM63268
SoCs.

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/mdio/Kconfig b/drivers/net/mdio/Kconfig
index a10cc460d7cf8cb34f2e014e498e86d0bc62efb5..d06e06f5e31ab4c81bbcb4766169bf2d3f3cf93e 100644 (file)
--- a/drivers/net/mdio/Kconfig
+++ b/drivers/net/mdio/Kconfig
@@ -200,6 +200,17 @@ config MDIO_BUS_MUX_MESON_G12A
          the amlogic g12a SoC. The multiplexers connects either the external
          or the internal MDIO bus to the parent bus.
 
+config MDIO_BUS_MUX_BCM6368
+       tristate "Broadcom BCM6368 MDIO bus multiplexers"
+       depends on OF && OF_MDIO && (BMIPS_GENERIC || COMPILE_TEST)
+       select MDIO_BUS_MUX
+       default BMIPS_GENERIC
+       help
+         This module provides a driver for MDIO bus multiplexers found in
+         BCM6368 based Broadcom SoCs. This multiplexer connects one of several
+         child MDIO bus to a parent bus. Buses could be internal as well as
+         external and selection logic lies inside the same multiplexer.
+
 config MDIO_BUS_MUX_BCM_IPROC
        tristate "Broadcom iProc based MDIO bus multiplexers"
        depends on OF && OF_MDIO && (ARCH_BCM_IPROC || COMPILE_TEST)

diff --git a/drivers/net/mdio/Makefile b/drivers/net/mdio/Makefile
index 5c498dde463ffcdde75b8fe0151785a64ecb9591..c3ec0ef989df4263168b79c2989d224fc7fbbc0d 100644 (file)
--- a/drivers/net/mdio/Makefile
+++ b/drivers/net/mdio/Makefile
@@ -22,6 +22,7 @@ obj-$(CONFIG_MDIO_THUNDER)            += mdio-thunder.o
 obj-$(CONFIG_MDIO_XGENE)               += mdio-xgene.o
 
 obj-$(CONFIG_MDIO_BUS_MUX)             += mdio-mux.o
+obj-$(CONFIG_MDIO_BUS_MUX_BCM6368)     += mdio-mux-bcm6368.o
 obj-$(CONFIG_MDIO_BUS_MUX_BCM_IPROC)   += mdio-mux-bcm-iproc.o
 obj-$(CONFIG_MDIO_BUS_MUX_GPIO)                += mdio-mux-gpio.o
 obj-$(CONFIG_MDIO_BUS_MUX_MESON_G12A)  += mdio-mux-meson-g12a.o

diff --git a/drivers/net/mdio/mdio-mux-bcm6368.c b/drivers/net/mdio/mdio-mux-bcm6368.c
new file mode 100644 (file)
index 0000000..6dcbf98
--- /dev/null
+++ b/drivers/net/mdio/mdio-mux-bcm6368.c
@@ -0,0 +1,184 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Broadcom BCM6368 mdiomux bus controller driver
+ *
+ * Copyright (C) 2021 Álvaro Fernández Rojas <noltari@gmail.com>
+ */
+
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mdio-mux.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/of_mdio.h>
+#include <linux/phy.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+
+#define MDIOC_REG              0x0
+#define MDIOC_EXT_MASK         BIT(16)
+#define MDIOC_REG_SHIFT                20
+#define MDIOC_PHYID_SHIFT      25
+#define MDIOC_RD_MASK          BIT(30)
+#define MDIOC_WR_MASK          BIT(31)
+
+#define MDIOD_REG              0x4
+
+struct bcm6368_mdiomux_desc {
+       void *mux_handle;
+       void __iomem *base;
+       struct device *dev;
+       struct mii_bus *mii_bus;
+       int ext_phy;
+};
+
+static int bcm6368_mdiomux_read(struct mii_bus *bus, int phy_id, int loc)
+{
+       struct bcm6368_mdiomux_desc *md = bus->priv;
+       uint32_t reg;
+       int ret;
+
+       __raw_writel(0, md->base + MDIOC_REG);
+
+       reg = MDIOC_RD_MASK |
+             (phy_id << MDIOC_PHYID_SHIFT) |
+             (loc << MDIOC_REG_SHIFT);
+       if (md->ext_phy)
+               reg |= MDIOC_EXT_MASK;
+
+       __raw_writel(reg, md->base + MDIOC_REG);
+       udelay(50);
+       ret = __raw_readw(md->base + MDIOD_REG);
+
+       return ret;
+}
+
+static int bcm6368_mdiomux_write(struct mii_bus *bus, int phy_id, int loc,
+                                uint16_t val)
+{
+       struct bcm6368_mdiomux_desc *md = bus->priv;
+       uint32_t reg;
+
+       __raw_writel(0, md->base + MDIOC_REG);
+
+       reg = MDIOC_WR_MASK |
+             (phy_id << MDIOC_PHYID_SHIFT) |
+             (loc << MDIOC_REG_SHIFT);
+       if (md->ext_phy)
+               reg |= MDIOC_EXT_MASK;
+       reg |= val;
+
+       __raw_writel(reg, md->base + MDIOC_REG);
+       udelay(50);
+
+       return 0;
+}
+
+static int bcm6368_mdiomux_switch_fn(int current_child, int desired_child,
+                                    void *data)
+{
+       struct bcm6368_mdiomux_desc *md = data;
+
+       md->ext_phy = desired_child;
+
+       return 0;
+}
+
+static int bcm6368_mdiomux_probe(struct platform_device *pdev)
+{
+       struct bcm6368_mdiomux_desc *md;
+       struct mii_bus *bus;
+       struct resource *res;
+       int rc;
+
+       md = devm_kzalloc(&pdev->dev, sizeof(*md), GFP_KERNEL);
+       if (!md)
+               return -ENOMEM;
+       md->dev = &pdev->dev;
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       if (!res)
+               return -EINVAL;
+
+       /*
+        * Just ioremap, as this MDIO block is usually integrated into an
+        * Ethernet MAC controller register range
+        */
+       md->base = devm_ioremap(&pdev->dev, res->start, resource_size(res));
+       if (!md->base) {
+               dev_err(&pdev->dev, "failed to ioremap register\n");
+               return -ENOMEM;
+       }
+
+       md->mii_bus = devm_mdiobus_alloc(&pdev->dev);
+       if (!md->mii_bus) {
+               dev_err(&pdev->dev, "mdiomux bus alloc failed\n");
+               return ENOMEM;
+       }
+
+       bus = md->mii_bus;
+       bus->priv = md;
+       bus->name = "BCM6368 MDIO mux bus";
+       snprintf(bus->id, MII_BUS_ID_SIZE, "%s-%d", pdev->name, pdev->id);
+       bus->parent = &pdev->dev;
+       bus->read = bcm6368_mdiomux_read;
+       bus->write = bcm6368_mdiomux_write;
+       bus->phy_mask = 0x3f;
+       bus->dev.of_node = pdev->dev.of_node;
+
+       rc = mdiobus_register(bus);
+       if (rc) {
+               dev_err(&pdev->dev, "mdiomux registration failed\n");
+               return rc;
+       }
+
+       platform_set_drvdata(pdev, md);
+
+       rc = mdio_mux_init(md->dev, md->dev->of_node,
+                          bcm6368_mdiomux_switch_fn, &md->mux_handle, md,
+                          md->mii_bus);
+       if (rc) {
+               dev_info(md->dev, "mdiomux initialization failed\n");
+               goto out_register;
+       }
+
+       dev_info(&pdev->dev, "Broadcom BCM6368 MDIO mux bus\n");
+
+       return 0;
+
+out_register:
+       mdiobus_unregister(bus);
+       return rc;
+}
+
+static int bcm6368_mdiomux_remove(struct platform_device *pdev)
+{
+       struct bcm6368_mdiomux_desc *md = platform_get_drvdata(pdev);
+
+       mdio_mux_uninit(md->mux_handle);
+       mdiobus_unregister(md->mii_bus);
+
+       return 0;
+}
+
+static const struct of_device_id bcm6368_mdiomux_ids[] = {
+       { .compatible = "brcm,bcm6368-mdio-mux", },
+       { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, bcm6368_mdiomux_ids);
+
+static struct platform_driver bcm6368_mdiomux_driver = {
+       .driver = {
+               .name = "bcm6368-mdio-mux",
+               .of_match_table = bcm6368_mdiomux_ids,
+       },
+       .probe  = bcm6368_mdiomux_probe,
+       .remove = bcm6368_mdiomux_remove,
+};
+module_platform_driver(bcm6368_mdiomux_driver);
+
+MODULE_AUTHOR("Álvaro Fernández Rojas <noltari@gmail.com>");
+MODULE_DESCRIPTION("BCM6368 mdiomux bus controller driver");
+MODULE_LICENSE("GPL v2");