From: Vivek Pernamitta <redacted>

Add support to configure a new client as Ethernet type over MHI by
setting "mhi_device_info.ethernet_if = true". Create a new Ethernet
interface named eth%d. This complements existing NET driver support.

Introduce IP_SW1, ETH0, and ETH1 network interfaces required for
M-plane, NETCONF, and S-plane components.

M-plane:
Implement DU M-Plane software for non-real-time O-RAN management
between O-DU and O-RU using NETCONF/YANG and O-RAN WG4 M-Plane YANG
models. Provide capability exchange, configuration management,
performance monitoring, and fault management per O-RAN.WG4.TS.MP.0-
R004-v18.00.

NETCONF:
Use NETCONF protocol for configuration operations such as fetching,
modifying, and deleting network device configurations.

S-plane:
Support frequency and time synchronization between O-DUs and O-RUs
using Synchronous Ethernet and IEEE 1588. Assume PTP transport over
L2 Ethernet (ITU-T G.8275.1) for full timing support; allow PTP over
UDP/IP (ITU-T G.8275.2) with reduced reliability. as per ORAN spec
O-RAN.WG4.CUS.0-R003-v12.00.

Signed-off-by: Vivek Pernamitta <redacted>
---
 drivers/net/mhi_net.c | 75 ++++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 62 insertions(+), 13 deletions(-)

diff --git a/drivers/net/mhi_net.c b/drivers/net/mhi_net.c
index ae169929a9d8e449b5a427993abf68e8d032fae2..fbec10c1ba9faf1ccf049b808e9d391800320989 100644
--- a/drivers/net/mhi_net.c
+++ b/drivers/net/mhi_net.c

@@ -4,6 +4,7 @@
  * Copyright (C) 2020 Linaro Ltd <loic.poulain@linaro.org>
  */

+#include <linux/etherdevice.h>
 #include <linux/if_arp.h>
 #include <linux/mhi.h>
 #include <linux/mod_devicetable.h>

@@ -38,10 +39,12 @@ struct mhi_net_dev {
        u32 rx_queue_sz;
        int msg_enable;
        unsigned int mru;
+       bool ethernet_if;
 };

 struct mhi_device_info {
        const char *netname;
+       bool ethernet_if;
 };

 static int mhi_ndo_open(struct net_device *ndev)

@@ -119,11 +122,29 @@ static void mhi_ndo_get_stats64(struct net_device *ndev,
        } while (u64_stats_fetch_retry(&mhi_netdev->stats.tx_syncp, start));
 }

+static int mhi_mac_address(struct net_device *dev, void *p)
+{
+       if (dev->type == ARPHRD_ETHER)
+               return eth_mac_addr(dev, p);
+
+       return 0;
+}
+
+static int mhi_validate_address(struct net_device *dev)
+{
+       if (dev->type == ARPHRD_ETHER)
+               return eth_validate_addr(dev);
+
+       return 0;
+}
+
 static const struct net_device_ops mhi_netdev_ops = {
        .ndo_open               = mhi_ndo_open,
        .ndo_stop               = mhi_ndo_stop,
        .ndo_start_xmit         = mhi_ndo_xmit,
        .ndo_get_stats64        = mhi_ndo_get_stats64,
+       .ndo_set_mac_address    = mhi_mac_address,
+       .ndo_validate_addr      = mhi_validate_address,
 };

 static void mhi_net_setup(struct net_device *ndev)

@@ -140,6 +161,13 @@ static void mhi_net_setup(struct net_device *ndev)
        ndev->tx_queue_len = 1000;
 }

+static void mhi_ethernet_setup(struct net_device *ndev)
+{
+       ndev->netdev_ops = &mhi_netdev_ops;
+       ether_setup(ndev);
+       ndev->max_mtu = ETH_MAX_MTU;
+}
+
 static struct sk_buff *mhi_net_skb_agg(struct mhi_net_dev *mhi_netdev,
                                       struct sk_buff *skb)
 {

@@ -209,16 +237,22 @@ static void mhi_net_dl_callback(struct mhi_device *mhi_dev,
                        mhi_netdev->skbagg_head = NULL;
                }

-               switch (skb->data[0] & 0xf0) {
-               case 0x40:
-                       skb->protocol = htons(ETH_P_IP);
-                       break;
-               case 0x60:
-                       skb->protocol = htons(ETH_P_IPV6);
-                       break;
-               default:
-                       skb->protocol = htons(ETH_P_MAP);
-                       break;
+               if (mhi_netdev->ethernet_if) {
+                       skb_copy_to_linear_data(skb, skb->data,
+                                               mhi_res->bytes_xferd);

+                       skb->protocol = eth_type_trans(skb, mhi_netdev->ndev);
+               } else {
+                       switch (skb->data[0] & 0xf0) {
+                       case 0x40:
+                               skb->protocol = htons(ETH_P_IP);
+                               break;
+                       case 0x60:
+                               skb->protocol = htons(ETH_P_IPV6);
+                               break;
+                       default:
+                               skb->protocol = htons(ETH_P_MAP);
+                               break;
+                       }
                }

                u64_stats_update_begin(&mhi_netdev->stats.rx_syncp);

@@ -301,11 +335,14 @@ static void mhi_net_rx_refill_work(struct work_struct *work)
                schedule_delayed_work(&mhi_netdev->rx_refill, HZ / 2);
 }

-static int mhi_net_newlink(struct mhi_device *mhi_dev, struct net_device *ndev)
+static int mhi_net_newlink(struct mhi_device *mhi_dev, struct net_device *ndev, bool eth_dev)
 {
        struct mhi_net_dev *mhi_netdev;
        int err;

+       if (eth_dev)
+               eth_hw_addr_random(ndev);
+
        mhi_netdev = netdev_priv(ndev);

        dev_set_drvdata(&mhi_dev->dev, mhi_netdev);

@@ -313,6 +350,7 @@ static int mhi_net_newlink(struct mhi_device *mhi_dev, struct net_device *ndev)
        mhi_netdev->mdev = mhi_dev;
        mhi_netdev->skbagg_head = NULL;
        mhi_netdev->mru = mhi_dev->mhi_cntrl->mru;
+       mhi_netdev->ethernet_if = eth_dev;

        INIT_DELAYED_WORK(&mhi_netdev->rx_refill, mhi_net_rx_refill_work);
        u64_stats_init(&mhi_netdev->stats.rx_syncp);

@@ -356,13 +394,14 @@ static int mhi_net_probe(struct mhi_device *mhi_dev,
        int err;

        ndev = alloc_netdev(sizeof(struct mhi_net_dev), info->netname,
-                           NET_NAME_PREDICTABLE, mhi_net_setup);
+                           NET_NAME_ENUM, info->ethernet_if ?
+                           mhi_ethernet_setup : mhi_net_setup);
        if (!ndev)
                return -ENOMEM;

        SET_NETDEV_DEV(ndev, &mhi_dev->dev);

-       err = mhi_net_newlink(mhi_dev, ndev);
+       err = mhi_net_newlink(mhi_dev, ndev, info->ethernet_if);
        if (err) {
                free_netdev(ndev);
                return err;

@@ -380,10 +419,17 @@ static void mhi_net_remove(struct mhi_device *mhi_dev)

 static const struct mhi_device_info mhi_hwip0 = {
        .netname = "mhi_hwip%d",
+       .ethernet_if = false,
 };

 static const struct mhi_device_info mhi_swip0 = {
        .netname = "mhi_swip%d",
+       .ethernet_if = false,
+};
+
+static const struct mhi_device_info mhi_eth0 = {
+       .netname = "eth%d",
+       .ethernet_if = true,
 };

 static const struct mhi_device_id mhi_net_id_table[] = {

@@ -391,6 +437,9 @@ static const struct mhi_device_id mhi_net_id_table[] = {
        { .chan = "IP_HW0", .driver_data = (kernel_ulong_t)&mhi_hwip0 },
        /* Software data PATH (to modem CPU) */
        { .chan = "IP_SW0", .driver_data = (kernel_ulong_t)&mhi_swip0 },
+       { .chan = "IP_SW1", .driver_data = (kernel_ulong_t)&mhi_swip0 },
+       { .chan = "IP_ETH0", .driver_data = (kernel_ulong_t)&mhi_eth0 },
+       { .chan = "IP_ETH1", .driver_data = (kernel_ulong_t)&mhi_eth0 },
        {}
 };
 MODULE_DEVICE_TABLE(mhi, mhi_net_id_table);

--

2.34.1