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- /* 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__ */
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