[PATCH net-next v2 2/2] net: maxlinear: Add support for MxL LGM SoC

[Jack Ping CHNG <jchng@maxlinear.com>]

Introduce the build system integration and initial implementation for the
MaxLinear LGM SoC Ethernet driver. This patch adds Kconfig and Makefile
entries, the main driver source file, and documentation.

Signed-off-by: Jack Ping CHNG <jchng@maxlinear.com>
---
 .../device_drivers/ethernet/index.rst         |   1 +
 .../device_drivers/ethernet/maxlinear/mxl.rst |  61 ++++++
 MAINTAINERS                                   |   8 +
 drivers/net/ethernet/Kconfig                  |   1 +
 drivers/net/ethernet/Makefile                 |   1 +
 drivers/net/ethernet/maxlinear/Kconfig        |  15 ++
 drivers/net/ethernet/maxlinear/Makefile       |   6 +
 drivers/net/ethernet/maxlinear/mxl_eth.c      | 189 ++++++++++++++++++
 8 files changed, 282 insertions(+)
 create mode 100644 Documentation/networking/device_drivers/ethernet/maxlinear/mxl.rst
 create mode 100644 drivers/net/ethernet/maxlinear/Kconfig
 create mode 100644 drivers/net/ethernet/maxlinear/Makefile
 create mode 100644 drivers/net/ethernet/maxlinear/mxl_eth.c

diff --git a/Documentation/networking/device_drivers/ethernet/index.rst b/Documentation/networking/device_drivers/ethernet/index.rst
index 40ac552641a3..13d3cbc96e87 100644
--- a/Documentation/networking/device_drivers/ethernet/index.rst
+++ b/Documentation/networking/device_drivers/ethernet/index.rst
@@ -44,6 +44,7 @@ Contents:
    marvell/octeontx2
    marvell/octeon_ep
    marvell/octeon_ep_vf
+   maxlinear/mxl
    mellanox/mlx5/index
    meta/fbnic
    microsoft/netvsc
diff --git a/Documentation/networking/device_drivers/ethernet/maxlinear/mxl.rst b/Documentation/networking/device_drivers/ethernet/maxlinear/mxl.rst
new file mode 100644
index 000000000000..7954c47347e7
--- /dev/null
+++ b/Documentation/networking/device_drivers/ethernet/maxlinear/mxl.rst
@@ -0,0 +1,61 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===============================================
+MaxLinear Multi-MAC Network Processor (NP)
+===============================================
+
+Copyright(c) 2025 MaxLinear, Inc.
+
+Overview
+========
+
+This document describes the Linux driver for the MaxLinear Network Processor
+(NP), a high-performance controller supporting multiple MACs and
+advanced packet processing capabilities.
+
+The MaxLinear Network processor integrates programmable hardware accelerators
+for tasks such as Layer 2, 3, 4 forwarding, flow steering, and traffic shaping.
+It is designed to operate in high-throughput applications, including data
+center switching, virtualized environments, and telco infrastructure.
+
+Key Features
+============
+
+- Support for up to 4 independent 10 Gbit/s MAC interfaces
+- Full-duplex 10G operation
+- Multiqueue support for parallel RX/TX paths (per MAC)
+
+Supported Devices
+=================
+
+The driver supports the following MaxLinear NPU family devices:
+- MaxLinear LGM
+
+Each device supports multiple MACs and high-performance data pipelines managed
+through internal firmware and programmable engines.
+
+Kernel Configuration
+====================
+
+The driver is located in the menu structure at:
+
+  -> Device Drivers
+    -> Network device support
+      -> Ethernet driver support
+        -> MaxLinear NPU Ethernet driver
+
+Or set in your kernel config:
+  CONFIG_NET_VENDOR_MAXLINEAR=y
+  CONFIG_MAXLINEAR_ETH=y
+
+Maintainers
+===========
+
+See the MAINTAINERS file:
+
+    MAXLINEAR ETHERNET DRIVER
+    M: Jack Ping Chng <jchng@maxlinear.com>
+    L: netdev@vger.kernel.org
+    S: Supported
+    F: drivers/net/ethernet/maxlinear/
+
diff --git a/MAINTAINERS b/MAINTAINERS
index fe168477caa4..e4765bd73615 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -15102,6 +15102,14 @@ W:	https://linuxtv.org
 T:	git git://linuxtv.org/media.git
 F:	drivers/media/radio/radio-maxiradio*
 
+MAXLINEAR ETHERNET DRIVER
+M:	Jack Ping Chng <jchng@maxlinear.com>
+L:	netdev@vger.kernel.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/net/mxl,lgm-eth.yaml
+F:	Documentation/networking/device_drivers/ethernet/maxlinear/mxl.rst
+F:	drivers/net/ethernet/maxlinear/mxl_eth.c
+
 MAXLINEAR ETHERNET PHY DRIVER
 M:	Xu Liang <lxu@maxlinear.com>
 L:	netdev@vger.kernel.org
diff --git a/drivers/net/ethernet/Kconfig b/drivers/net/ethernet/Kconfig
index f86d4557d8d7..3e94ff7922c8 100644
--- a/drivers/net/ethernet/Kconfig
+++ b/drivers/net/ethernet/Kconfig
@@ -121,6 +121,7 @@ config LANTIQ_XRX200
 source "drivers/net/ethernet/adi/Kconfig"
 source "drivers/net/ethernet/litex/Kconfig"
 source "drivers/net/ethernet/marvell/Kconfig"
+source "drivers/net/ethernet/maxlinear/Kconfig"
 source "drivers/net/ethernet/mediatek/Kconfig"
 source "drivers/net/ethernet/mellanox/Kconfig"
 source "drivers/net/ethernet/meta/Kconfig"
diff --git a/drivers/net/ethernet/Makefile b/drivers/net/ethernet/Makefile
index 67182339469a..760d598df197 100644
--- a/drivers/net/ethernet/Makefile
+++ b/drivers/net/ethernet/Makefile
@@ -58,6 +58,7 @@ obj-$(CONFIG_LANTIQ_ETOP) += lantiq_etop.o
 obj-$(CONFIG_LANTIQ_XRX200) += lantiq_xrx200.o
 obj-$(CONFIG_NET_VENDOR_LITEX) += litex/
 obj-$(CONFIG_NET_VENDOR_MARVELL) += marvell/
+obj-$(CONFIG_NET_VENDOR_MAXLINEAR) += maxlinear/
 obj-$(CONFIG_NET_VENDOR_MEDIATEK) += mediatek/
 obj-$(CONFIG_NET_VENDOR_MELLANOX) += mellanox/
 obj-$(CONFIG_NET_VENDOR_META) += meta/
diff --git a/drivers/net/ethernet/maxlinear/Kconfig b/drivers/net/ethernet/maxlinear/Kconfig
new file mode 100644
index 000000000000..b88cdd9675fb
--- /dev/null
+++ b/drivers/net/ethernet/maxlinear/Kconfig
@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config NET_VENDOR_MAXLINEAR
+	bool "MaxLinear devices"
+	help
+	  If you have a MaxLinear SoC with ethernet, say Y.
+
+if NET_VENDOR_MAXLINEAR
+
+config MXL_NPU
+	tristate "MaxLinear NPU Ethernet driver"
+	help
+	  This driver supports the MaxLinear NPU Ethernet.
+
+endif #NET_VENDOR_MAXLINEAR
+
diff --git a/drivers/net/ethernet/maxlinear/Makefile b/drivers/net/ethernet/maxlinear/Makefile
new file mode 100644
index 000000000000..0577b325494c
--- /dev/null
+++ b/drivers/net/ethernet/maxlinear/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for the MaxLinear network device drivers.
+#
+
+obj-$(CONFIG_MXL_NPU) += mxl_eth.o
diff --git a/drivers/net/ethernet/maxlinear/mxl_eth.c b/drivers/net/ethernet/maxlinear/mxl_eth.c
new file mode 100644
index 000000000000..093ad9b27a81
--- /dev/null
+++ b/drivers/net/ethernet/maxlinear/mxl_eth.c
@@ -0,0 +1,189 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2025  MaxLinear, Inc.
+ */
+#include <linux/clk.h>
+#include <linux/etherdevice.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+
+#define ETH_TX_TIMEOUT		(10 * HZ)
+#define MXL_NUM_TX_RING		8
+#define MXL_NUM_RX_RING		8
+#define MXL_NUM_PORT		2
+
+struct mxl_eth_drvdata {
+	struct net_device *ndevs[MXL_NUM_PORT];
+	struct clk *clks;
+};
+
+struct eth_priv {
+	struct platform_device *pdev;
+	struct device_node *np;
+};
+
+static int mxl_eth_open(struct net_device *ndev)
+{
+	netif_carrier_on(ndev);
+	netif_start_queue(ndev);
+	return 0;
+}
+
+static int mxl_eth_stop(struct net_device *ndev)
+{
+	netif_stop_queue(ndev);
+	netif_carrier_off(ndev);
+	return 0;
+}
+
+static int mxl_eth_start_xmit(struct sk_buff *skb, struct net_device *ndev)
+{
+	dev_kfree_skb(skb);
+	return NETDEV_TX_OK;
+}
+
+static const struct net_device_ops mxl_eth_netdev_ops = {
+	.ndo_open       = mxl_eth_open,
+	.ndo_stop       = mxl_eth_stop,
+	.ndo_start_xmit = mxl_eth_start_xmit,
+};
+
+static int mxl_eth_create_ndev(struct platform_device *pdev,
+			       struct device_node *np,
+			       struct net_device **ndev_out)
+{
+	struct net_device *ndev;
+	struct eth_priv *priv;
+	int ret;
+
+	ndev = devm_alloc_etherdev_mqs(&pdev->dev, sizeof(struct eth_priv),
+				       MXL_NUM_TX_RING, MXL_NUM_RX_RING);
+	if (!ndev) {
+		dev_err(&pdev->dev, "alloc_etherdev_mq failed\n");
+		return -ENOMEM;
+	}
+
+	ndev->netdev_ops = &mxl_eth_netdev_ops;
+	ndev->watchdog_timeo = ETH_TX_TIMEOUT;
+	ndev->max_mtu = ETH_FRAME_LEN;
+	ndev->min_mtu = ETH_MIN_MTU;
+	SET_NETDEV_DEV(ndev, &pdev->dev);
+
+	priv = netdev_priv(ndev);
+	priv->pdev = pdev;
+	priv->np = np;
+
+	ret = register_netdev(ndev);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register net device\n");
+		return ret;
+	}
+
+	*ndev_out = ndev;
+	return 0;
+}
+
+static void mxl_eth_cleanup(struct mxl_eth_drvdata *drvdata)
+{
+	int i;
+
+	for (i = 0; i < MXL_NUM_PORT && drvdata->ndevs[i]; i++) {
+		unregister_netdev(drvdata->ndevs[i]);
+		drvdata->ndevs[i] = NULL;
+	}
+}
+
+static int mxl_eth_probe(struct platform_device *pdev)
+{
+	struct mxl_eth_drvdata *drvdata;
+	struct reset_control *rst;
+	struct net_device *ndev;
+	struct device_node *np;
+	int ret, i;
+
+	drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL);
+	if (!drvdata)
+		return -ENOMEM;
+
+	drvdata->clks = devm_clk_get_enabled(&pdev->dev, "ethif");
+	if (IS_ERR(drvdata->clks))
+		return dev_err_probe(&pdev->dev, PTR_ERR(drvdata->clks),
+				     "failed to get/enable clock\n");
+
+	rst = devm_reset_control_get_optional(&pdev->dev, NULL);
+	if (IS_ERR(rst)) {
+		dev_err(&pdev->dev,
+			"failed to get optional reset control: %ld\n",
+			PTR_ERR(rst));
+		ret = PTR_ERR(rst);
+		goto err_cleanup;
+	}
+
+	if (rst) {
+		ret = reset_control_assert(rst);
+		if (ret)
+			goto err_cleanup;
+
+		udelay(1);
+
+		ret = reset_control_deassert(rst);
+		if (ret)
+			goto err_cleanup;
+	}
+
+	platform_set_drvdata(pdev, drvdata);
+
+	i = 0;
+	for_each_available_child_of_node(pdev->dev.of_node, np) {
+		if (!of_device_is_compatible(np, "mxl,eth-mac"))
+			continue;
+
+		ret = mxl_eth_create_ndev(pdev, np, &ndev);
+		if (ret)
+			goto err_cleanup;
+
+		drvdata->ndevs[i++] = ndev;
+		if (i >= MXL_NUM_PORT)
+			break;
+	}
+
+	return 0;
+
+err_cleanup:
+	mxl_eth_cleanup(drvdata);
+	return ret;
+}
+
+static void mxl_eth_remove(struct platform_device *pdev)
+{
+	struct mxl_eth_drvdata *drvdata = platform_get_drvdata(pdev);
+
+	mxl_eth_cleanup(drvdata);
+}
+
+/* Device Tree match table */
+static const struct of_device_id mxl_eth_of_match[] = {
+	{ .compatible = "mxl,lgm-eth" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, mxl_eth_of_match);
+
+/* Platform driver struct */
+static struct platform_driver mxl_eth_drv = {
+	.probe    = mxl_eth_probe,
+	.remove   = mxl_eth_remove,
+	.driver = {
+		.name = KBUILD_MODNAME,
+		.of_match_table = mxl_eth_of_match,
+	},
+};
+
+module_platform_driver(mxl_eth_drv);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Ethernet driver for MxL SoC");
-- 
2.34.1