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Diffstat (limited to 'include/net/dsa.h')
| -rw-r--r-- | include/net/dsa.h | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/include/net/dsa.h b/include/net/dsa.h new file mode 100644 index 0000000000..0f31a908c9 --- /dev/null +++ b/include/net/dsa.h @@ -0,0 +1,165 @@ +/* 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__ */ |