--- /dev/null
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright 2019-2021 NXP Semiconductors
+ */
+
+#ifndef __DSA_H__
+#define __DSA_H__
+
+#include <phy.h>
+#include <net.h>
+
+/**
+ * DSA stands for Distributed Switch Architecture and it is infrastructure
+ * intended to support drivers for Switches that rely on an intermediary
+ * Ethernet device for I/O. These switches may support cascading allowing
+ * them to be arranged as a tree.
+ * DSA is documented in detail in the Linux kernel documentation under
+ * Documentation/networking/dsa/dsa.txt
+ * The network layout of such a switch is shown below:
+ *
+ * |------|
+ * | eth0 | <--- master eth device (regular eth driver)
+ * |------|
+ * ^ |
+ * tag added by switch -->| |
+ * | |
+ * | |<-- tag added by DSA driver
+ * | v
+ * |--------------------------------------|
+ * | | CPU port | | <-- DSA (switch) device
+ * | ------------ | (DSA driver)
+ * | _________ _________ _________ |
+ * | | port0 | | port1 | ... | portn | | <-- ports as eth devices
+ * |-+-------+--+-------+-------+-------+-| ('dsa-port' eth driver)
+ *
+ * In U-Boot the intent is to allow access to front panel ports (shown at the
+ * bottom of the picture) through the master Ethernet dev (eth0 in the picture).
+ * Front panel ports are presented as regular Ethernet devices in U-Boot and
+ * they are expected to support the typical networking commands.
+ * In general DSA switches require the use of tags, extra headers added both by
+ * software on Tx and by the switch on Rx. These tags carry at a minimum port
+ * information and switch information for cascaded set-ups.
+ * In U-Boot these tags are inserted and parsed by the DSA switch driver, the
+ * class code helps with headroom/tailroom for the extra headers.
+ *
+ * TODO:
+ * - handle switch cascading, for now U-Boot only supports stand-alone switches.
+ * - Add support to probe DSA switches connected to a MDIO bus, this is needed
+ * to convert switch drivers that are now under drivers/net/phy.
+ */
+
+#define DSA_PORT_NAME_LENGTH 16
+
+/* Maximum number of ports each DSA device can have */
+#define DSA_MAX_PORTS 12
+
+/**
+ * struct dsa_ops - DSA operations
+ *
+ * @port_enable: Initialize a switch port for I/O.
+ * @port_disable: Disable I/O for a port.
+ * @xmit: Insert the DSA tag for transmission.
+ * DSA drivers receive a copy of the packet with headroom and
+ * tailroom reserved and set to 0. 'packet' points to headroom
+ * and 'length' is updated to include both head and tailroom.
+ * @rcv: Process the DSA tag on reception and return the port index
+ * from the h/w provided tag. Return the index via 'portp'.
+ * 'packet' and 'length' describe the frame as received from
+ * master including any additional headers.
+ */
+struct dsa_ops {
+ int (*port_enable)(struct udevice *dev, int port,
+ struct phy_device *phy);
+ void (*port_disable)(struct udevice *dev, int port,
+ struct phy_device *phy);
+ int (*xmit)(struct udevice *dev, int port, void *packet, int length);
+ int (*rcv)(struct udevice *dev, int *portp, void *packet, int length);
+};
+
+#define dsa_get_ops(dev) ((struct dsa_ops *)(dev)->driver->ops)
+
+/**
+ * struct dsa_port_pdata - DSA port platform data
+ *
+ * @phy: PHY device associated with this port.
+ * The uclass code attempts to set this field for all ports except CPU
+ * port, based on DT information. It may be NULL.
+ * @index: Port index in the DSA switch, set by the uclass code.
+ * @name: Name of the port Eth device. If a label property is present in the
+ * port DT node, it is used as name.
+ */
+struct dsa_port_pdata {
+ struct phy_device *phy;
+ u32 index;
+ char name[DSA_PORT_NAME_LENGTH];
+};
+
+/**
+ * struct dsa_pdata - Per-device platform data for DSA DM
+ *
+ * @num_ports: Number of ports the device has, must be <= DSA_MAX_PORTS.
+ * This number is extracted from the DT 'ports' node of this
+ * DSA device, and it counts the CPU port and all the other
+ * port subnodes including the disabled ones.
+ * @cpu_port: Index of the switch port linked to the master Ethernet.
+ * The uclass code sets this based on DT information.
+ * @master_node: OF node of the host Ethernet controller.
+ * @cpu_port_node: DT node of the switch's CPU port.
+ */
+struct dsa_pdata {
+ int num_ports;
+ u32 cpu_port;
+ ofnode master_node;
+ ofnode cpu_port_node;
+};
+
+/**
+ * dsa_set_tagging() - Configure the headroom and/or tailroom sizes
+ *
+ * The DSA class code allocates headroom and tailroom on Tx before
+ * calling the DSA driver's xmit function.
+ * All drivers must call this at probe time.
+ *
+ * @dev: DSA device pointer
+ * @headroom: Size, in bytes, of headroom needed for the DSA tag.
+ * @tailroom: Size, in bytes, of tailroom needed for the DSA tag.
+ * Total headroom and tailroom size should not exceed
+ * DSA_MAX_OVR.
+ * @return 0 if OK, -ve on error
+ */
+int dsa_set_tagging(struct udevice *dev, ushort headroom, ushort tailroom);
+
+/* DSA helpers */
+
+/**
+ * dsa_get_master() - Return a reference to the master Ethernet device
+ *
+ * Can be called at driver probe time or later.
+ *
+ * @dev: DSA device pointer
+ * @return Master Eth 'udevice' pointer if OK, NULL on error
+ */
+struct udevice *dsa_get_master(struct udevice *dev);
+
+/**
+ * dsa_port_get_pdata() - Helper that returns the platdata of an active
+ * (non-CPU) DSA port device.
+ *
+ * Can be called at driver probe time or later.
+ *
+ * @pdev: DSA port device pointer
+ * @return 'dsa_port_pdata' pointer if OK, NULL on error
+ */
+static inline struct dsa_port_pdata *
+ dsa_port_get_pdata(struct udevice *pdev)
+{
+ struct eth_pdata *eth = dev_get_plat(pdev);
+
+ if (!eth)
+ return NULL;
+
+ return eth->priv_pdata;
+}
+
+#endif /* __DSA_H__ */
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2019-2021 NXP
+ */
+
+#include <net/dsa.h>
+#include <dm/lists.h>
+#include <dm/device_compat.h>
+#include <dm/device-internal.h>
+#include <dm/uclass-internal.h>
+#include <linux/bitmap.h>
+#include <miiphy.h>
+
+#define DSA_PORT_CHILD_DRV_NAME "dsa-port"
+
+/* per-device internal state structure */
+struct dsa_priv {
+ struct phy_device *cpu_port_fixed_phy;
+ struct udevice *master_dev;
+ int num_ports;
+ u32 cpu_port;
+ int headroom;
+ int tailroom;
+};
+
+/* external API */
+int dsa_set_tagging(struct udevice *dev, ushort headroom, ushort tailroom)
+{
+ struct dsa_priv *priv;
+
+ if (!dev || !dev_get_uclass_priv(dev))
+ return -ENODEV;
+
+ if (headroom + tailroom > DSA_MAX_OVR)
+ return -EINVAL;
+
+ priv = dev_get_uclass_priv(dev);
+
+ if (headroom > 0)
+ priv->headroom = headroom;
+ if (tailroom > 0)
+ priv->tailroom = tailroom;
+
+ return 0;
+}
+
+/* returns the DSA master Ethernet device */
+struct udevice *dsa_get_master(struct udevice *dev)
+{
+ struct dsa_priv *priv = dev_get_uclass_priv(dev);
+
+ if (!priv)
+ return NULL;
+
+ return priv->master_dev;
+}
+
+/*
+ * Start the desired port, the CPU port and the master Eth interface.
+ * TODO: if cascaded we may need to _start ports in other switches too
+ */
+static int dsa_port_start(struct udevice *pdev)
+{
+ struct udevice *dev = dev_get_parent(pdev);
+ struct dsa_priv *priv = dev_get_uclass_priv(dev);
+ struct udevice *master = dsa_get_master(dev);
+ struct dsa_ops *ops = dsa_get_ops(dev);
+ int err;
+
+ if (!priv)
+ return -ENODEV;
+
+ if (!master) {
+ dev_err(pdev, "DSA master Ethernet device not found!\n");
+ return -EINVAL;
+ }
+
+ if (ops->port_enable) {
+ struct dsa_port_pdata *port_pdata;
+
+ port_pdata = dev_get_parent_plat(pdev);
+ err = ops->port_enable(dev, port_pdata->index,
+ port_pdata->phy);
+ if (err)
+ return err;
+
+ err = ops->port_enable(dev, priv->cpu_port,
+ priv->cpu_port_fixed_phy);
+ if (err)
+ return err;
+ }
+
+ return eth_get_ops(master)->start(master);
+}
+
+/* Stop the desired port, the CPU port and the master Eth interface */
+static void dsa_port_stop(struct udevice *pdev)
+{
+ struct udevice *dev = dev_get_parent(pdev);
+ struct dsa_priv *priv = dev_get_uclass_priv(dev);
+ struct udevice *master = dsa_get_master(dev);
+ struct dsa_ops *ops = dsa_get_ops(dev);
+
+ if (!priv)
+ return;
+
+ if (ops->port_disable) {
+ struct dsa_port_pdata *port_pdata;
+
+ port_pdata = dev_get_parent_plat(pdev);
+ ops->port_disable(dev, port_pdata->index, port_pdata->phy);
+ ops->port_disable(dev, priv->cpu_port, NULL);
+ }
+
+ /*
+ * stop master only if it's active, don't probe it otherwise.
+ * Under normal usage it would be active because we're using it, but
+ * during tear-down it may have been removed ahead of us.
+ */
+ if (master && device_active(master))
+ eth_get_ops(master)->stop(master);
+}
+
+/*
+ * Insert a DSA tag and call master Ethernet send on the resulting packet
+ * We copy the frame to a stack buffer where we have reserved headroom and
+ * tailroom space. Headroom and tailroom are set to 0.
+ */
+static int dsa_port_send(struct udevice *pdev, void *packet, int length)
+{
+ struct udevice *dev = dev_get_parent(pdev);
+ struct dsa_priv *priv = dev_get_uclass_priv(dev);
+ int head = priv->headroom, tail = priv->tailroom;
+ struct udevice *master = dsa_get_master(dev);
+ struct dsa_ops *ops = dsa_get_ops(dev);
+ uchar dsa_packet_tmp[PKTSIZE_ALIGN];
+ struct dsa_port_pdata *port_pdata;
+ int err;
+
+ if (!master)
+ return -EINVAL;
+
+ if (length + head + tail > PKTSIZE_ALIGN)
+ return -EINVAL;
+
+ memset(dsa_packet_tmp, 0, head);
+ memset(dsa_packet_tmp + head + length, 0, tail);
+ memcpy(dsa_packet_tmp + head, packet, length);
+ length += head + tail;
+ /* copy back to preserve original buffer alignment */
+ memcpy(packet, dsa_packet_tmp, length);
+
+ port_pdata = dev_get_parent_plat(pdev);
+ err = ops->xmit(dev, port_pdata->index, packet, length);
+ if (err)
+ return err;
+
+ return eth_get_ops(master)->send(master, packet, length);
+}
+
+/* Receive a frame from master Ethernet, process it and pass it on */
+static int dsa_port_recv(struct udevice *pdev, int flags, uchar **packetp)
+{
+ struct udevice *dev = dev_get_parent(pdev);
+ struct dsa_priv *priv = dev_get_uclass_priv(dev);
+ int head = priv->headroom, tail = priv->tailroom;
+ struct udevice *master = dsa_get_master(dev);
+ struct dsa_ops *ops = dsa_get_ops(dev);
+ struct dsa_port_pdata *port_pdata;
+ int length, port_index, err;
+
+ if (!master)
+ return -EINVAL;
+
+ length = eth_get_ops(master)->recv(master, flags, packetp);
+ if (length <= 0)
+ return length;
+
+ /*
+ * If we receive frames from a different port or frames that DSA driver
+ * doesn't like we discard them here.
+ * In case of discard we return with no frame and expect to be called
+ * again instead of looping here, so upper layer can deal with timeouts.
+ */
+ port_pdata = dev_get_parent_plat(pdev);
+ err = ops->rcv(dev, &port_index, *packetp, length);
+ if (err || port_index != port_pdata->index || (length <= head + tail)) {
+ if (eth_get_ops(master)->free_pkt)
+ eth_get_ops(master)->free_pkt(master, *packetp, length);
+ return -EAGAIN;
+ }
+
+ /*
+ * We move the pointer over headroom here to avoid a copy. If free_pkt
+ * gets called we move the pointer back before calling master free_pkt.
+ */
+ *packetp += head;
+
+ return length - head - tail;
+}
+
+static int dsa_port_free_pkt(struct udevice *pdev, uchar *packet, int length)
+{
+ struct udevice *dev = dev_get_parent(pdev);
+ struct udevice *master = dsa_get_master(dev);
+ struct dsa_priv *priv;
+
+ if (!master)
+ return -EINVAL;
+
+ priv = dev_get_uclass_priv(dev);
+ if (eth_get_ops(master)->free_pkt) {
+ /* return the original pointer and length to master Eth */
+ packet -= priv->headroom;
+ length += priv->headroom - priv->tailroom;
+
+ return eth_get_ops(master)->free_pkt(master, packet, length);
+ }
+
+ return 0;
+}
+
+static int dsa_port_of_to_pdata(struct udevice *pdev)
+{
+ struct dsa_port_pdata *port_pdata;
+ struct dsa_pdata *dsa_pdata;
+ struct eth_pdata *eth_pdata;
+ struct udevice *dev;
+ const char *label;
+ u32 index;
+ int err;
+
+ if (!pdev)
+ return -ENODEV;
+
+ err = ofnode_read_u32(dev_ofnode(pdev), "reg", &index);
+ if (err)
+ return err;
+
+ dev = dev_get_parent(pdev);
+ dsa_pdata = dev_get_uclass_plat(dev);
+
+ port_pdata = dev_get_parent_plat(pdev);
+ port_pdata->index = index;
+
+ label = ofnode_read_string(dev_ofnode(pdev), "label");
+ if (label)
+ strncpy(port_pdata->name, label, DSA_PORT_NAME_LENGTH);
+
+ eth_pdata = dev_get_plat(pdev);
+ eth_pdata->priv_pdata = port_pdata;
+
+ dev_dbg(pdev, "port %d node %s\n", port_pdata->index,
+ ofnode_get_name(dev_ofnode(pdev)));
+
+ return 0;
+}
+
+static const struct eth_ops dsa_port_ops = {
+ .start = dsa_port_start,
+ .send = dsa_port_send,
+ .recv = dsa_port_recv,
+ .stop = dsa_port_stop,
+ .free_pkt = dsa_port_free_pkt,
+};
+
+static int dsa_port_probe(struct udevice *pdev)
+{
+ struct udevice *dev = dev_get_parent(pdev);
+ struct eth_pdata *eth_pdata, *master_pdata;
+ unsigned char env_enetaddr[ARP_HLEN];
+ struct dsa_port_pdata *port_pdata;
+ struct dsa_priv *dsa_priv;
+ struct udevice *master;
+
+ port_pdata = dev_get_parent_plat(pdev);
+ dsa_priv = dev_get_uclass_priv(dev);
+
+ port_pdata->phy = dm_eth_phy_connect(pdev);
+ if (!port_pdata->phy)
+ return -ENODEV;
+
+ /*
+ * Inherit port's hwaddr from the DSA master, unless the port already
+ * has a unique MAC address specified in the environment.
+ */
+ eth_env_get_enetaddr_by_index("eth", dev_seq(pdev), env_enetaddr);
+ if (!is_zero_ethaddr(env_enetaddr))
+ return 0;
+
+ master = dsa_get_master(dev);
+ if (!master)
+ return 0;
+
+ master_pdata = dev_get_plat(master);
+ eth_pdata = dev_get_plat(pdev);
+ memcpy(eth_pdata->enetaddr, master_pdata->enetaddr, ARP_HLEN);
+ eth_env_set_enetaddr_by_index("eth", dev_seq(pdev),
+ master_pdata->enetaddr);
+
+ return 0;
+}
+
+static int dsa_port_remove(struct udevice *pdev)
+{
+ struct udevice *dev = dev_get_parent(pdev);
+ struct dsa_port_pdata *port_pdata;
+ struct dsa_priv *dsa_priv;
+
+ port_pdata = dev_get_parent_plat(pdev);
+ dsa_priv = dev_get_uclass_priv(dev);
+
+ port_pdata->phy = NULL;
+
+ return 0;
+}
+
+U_BOOT_DRIVER(dsa_port) = {
+ .name = DSA_PORT_CHILD_DRV_NAME,
+ .id = UCLASS_ETH,
+ .ops = &dsa_port_ops,
+ .probe = dsa_port_probe,
+ .remove = dsa_port_remove,
+ .of_to_plat = dsa_port_of_to_pdata,
+ .plat_auto = sizeof(struct eth_pdata),
+};
+
+/*
+ * This function mostly deals with pulling information out of the device tree
+ * into the pdata structure.
+ * It goes through the list of switch ports, registers an eth device for each
+ * front panel port and identifies the cpu port connected to master eth device.
+ * TODO: support cascaded switches
+ */
+static int dsa_post_bind(struct udevice *dev)
+{
+ struct dsa_pdata *pdata = dev_get_uclass_plat(dev);
+ ofnode node = dev_ofnode(dev), pnode;
+ int i, err, first_err = 0;
+
+ if (!pdata || !ofnode_valid(node))
+ return -ENODEV;
+
+ pdata->master_node = ofnode_null();
+
+ node = ofnode_find_subnode(node, "ports");
+ if (!ofnode_valid(node))
+ node = ofnode_find_subnode(node, "ethernet-ports");
+ if (!ofnode_valid(node)) {
+ dev_err(dev, "ports node is missing under DSA device!\n");
+ return -EINVAL;
+ }
+
+ pdata->num_ports = ofnode_get_child_count(node);
+ if (pdata->num_ports <= 0 || pdata->num_ports > DSA_MAX_PORTS) {
+ dev_err(dev, "invalid number of ports (%d)\n",
+ pdata->num_ports);
+ return -EINVAL;
+ }
+
+ /* look for the CPU port */
+ ofnode_for_each_subnode(pnode, node) {
+ u32 ethernet;
+
+ if (ofnode_read_u32(pnode, "ethernet", ðernet))
+ continue;
+
+ pdata->master_node = ofnode_get_by_phandle(ethernet);
+ pdata->cpu_port_node = pnode;
+ break;
+ }
+
+ if (!ofnode_valid(pdata->master_node)) {
+ dev_err(dev, "master eth node missing!\n");
+ return -EINVAL;
+ }
+
+ if (ofnode_read_u32(pnode, "reg", &pdata->cpu_port)) {
+ dev_err(dev, "CPU port node not valid!\n");
+ return -EINVAL;
+ }
+
+ dev_dbg(dev, "master node %s on port %d\n",
+ ofnode_get_name(pdata->master_node), pdata->cpu_port);
+
+ for (i = 0; i < pdata->num_ports; i++) {
+ char name[DSA_PORT_NAME_LENGTH];
+ struct udevice *pdev;
+
+ /*
+ * If this is the CPU port don't register it as an ETH device,
+ * we skip it on purpose since I/O to/from it from the CPU
+ * isn't useful.
+ */
+ if (i == pdata->cpu_port)
+ continue;
+
+ /*
+ * Set up default port names. If present, DT port labels
+ * will override the default port names.
+ */
+ snprintf(name, DSA_PORT_NAME_LENGTH, "%s@%d", dev->name, i);
+
+ ofnode_for_each_subnode(pnode, node) {
+ u32 reg;
+
+ if (ofnode_read_u32(pnode, "reg", ®))
+ continue;
+
+ if (reg == i)
+ break;
+ }
+
+ /*
+ * skip registration if port id not found or if the port
+ * is explicitly disabled in DT
+ */
+ if (!ofnode_valid(pnode) || !ofnode_is_available(pnode))
+ continue;
+
+ err = device_bind_driver_to_node(dev, DSA_PORT_CHILD_DRV_NAME,
+ name, pnode, &pdev);
+ if (pdev) {
+ struct dsa_port_pdata *port_pdata;
+
+ port_pdata = dev_get_parent_plat(pdev);
+ strncpy(port_pdata->name, name, DSA_PORT_NAME_LENGTH);
+ pdev->name = port_pdata->name;
+ }
+
+ /* try to bind all ports but keep 1st error */
+ if (err && !first_err)
+ first_err = err;
+ }
+
+ if (first_err)
+ return first_err;
+
+ dev_dbg(dev, "DSA ports successfully bound\n");
+
+ return 0;
+}
+
+/**
+ * Initialize the uclass per device internal state structure (priv).
+ * TODO: pick up references to other switch devices here, if we're cascaded.
+ */
+static int dsa_pre_probe(struct udevice *dev)
+{
+ struct dsa_pdata *pdata = dev_get_uclass_plat(dev);
+ struct dsa_priv *priv = dev_get_uclass_priv(dev);
+
+ if (!pdata || !priv)
+ return -ENODEV;
+
+ priv->num_ports = pdata->num_ports;
+ priv->cpu_port = pdata->cpu_port;
+ priv->cpu_port_fixed_phy = fixed_phy_create(pdata->cpu_port_node);
+ if (!priv->cpu_port_fixed_phy) {
+ dev_err(dev, "Failed to register fixed-link for CPU port\n");
+ return -ENODEV;
+ }
+
+ uclass_find_device_by_ofnode(UCLASS_ETH, pdata->master_node,
+ &priv->master_dev);
+ return 0;
+}
+
+UCLASS_DRIVER(dsa) = {
+ .id = UCLASS_DSA,
+ .name = "dsa",
+ .post_bind = dsa_post_bind,
+ .pre_probe = dsa_pre_probe,
+ .per_device_auto = sizeof(struct dsa_priv),
+ .per_device_plat_auto = sizeof(struct dsa_pdata),
+ .per_child_plat_auto = sizeof(struct dsa_port_pdata),
+ .flags = DM_UC_FLAG_SEQ_ALIAS,
+};
projects / u-boot.git / commitdiff