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| -rw-r--r-- | doc/driver-model/UDM-net.txt | 434 |
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diff --git a/doc/driver-model/UDM-net.txt b/doc/driver-model/UDM-net.txt new file mode 100644 index 0000000..e2ea8f5 --- /dev/null +++ b/doc/driver-model/UDM-net.txt @@ -0,0 +1,434 @@ +The U-Boot Driver Model Project +=============================== +Net system analysis +=================== +Marek Vasut <marek.vasut@gmail.com> +2012-03-03 + +I) Overview +----------- + +The networking subsystem already supports multiple devices. Therefore the +conversion shall not be very hard. + +The network subsystem is operated from net/eth.c, which tracks all registered +ethernet interfaces and calls their particular functions registered via +eth_register(). + +The eth_register() is called from the network driver initialization function, +which in turn is called most often either from "board_net_init()" or +"cpu_net_init()". This function has one important argument, which is the +"struct eth_device", defined at include/net.h: + +struct eth_device { + /* DRIVER: Name of the device */ + char name[NAMESIZE]; + /* DRIVER: MAC address */ + unsigned char enetaddr[6]; + /* DRIVER: Register base address */ + int iobase; + /* CORE: state of the device */ + int state; + + /* DRIVER: Device initialization function */ + int (*init) (struct eth_device*, bd_t*); + /* DRIVER: Function for sending packets */ + int (*send) (struct eth_device*, volatile void* packet, int length); + /* DRIVER: Function for receiving packets */ + int (*recv) (struct eth_device*); + /* DRIVER: Function to cease operation of the device */ + void (*halt) (struct eth_device*); + /* DRIVER: Function to send multicast packet (OPTIONAL) */ + int (*mcast) (struct eth_device*, u32 ip, u8 set); + /* DRIVER: Function to change ethernet MAC address */ + int (*write_hwaddr) (struct eth_device*); + /* CORE: Next device in the linked list of devices managed by net core */ + struct eth_device *next; + /* CORE: Device index */ + int index; + /* DRIVER: Driver's private data */ + void *priv; +}; + +This structure defines the particular driver, though also contains elements that +should not be exposed to the driver, like core state. + +Small, but important part of the networking subsystem is the PHY management +layer, whose drivers are contained in drivers/net/phy. These drivers register in +a very similar manner to network drivers, by calling "phy_register()" with the +argument of "struct phy_driver": + +struct phy_driver { + /* DRIVER: Name of the PHY driver */ + char *name; + /* DRIVER: UID of the PHY driver */ + unsigned int uid; + /* DRIVER: Mask for UID of the PHY driver */ + unsigned int mask; + /* DRIVER: MMDS of the PHY driver */ + unsigned int mmds; + /* DRIVER: Features the PHY driver supports */ + u32 features; + /* DRIVER: Initialize the PHY hardware */ + int (*probe)(struct phy_device *phydev); + /* DRIVER: Reconfigure the PHY hardware */ + int (*config)(struct phy_device *phydev); + /* DRIVER: Turn on the PHY hardware, allow it to send/receive */ + int (*startup)(struct phy_device *phydev); + /* DRIVER: Turn off the PHY hardware */ + int (*shutdown)(struct phy_device *phydev); + /* CORE: Allows this driver to be part of list of drivers */ + struct list_head list; +}; + +II) Approach +------------ + +To convert the elements of network subsystem to proper driver model method, the +"struct eth_device" will have to be split into multiple components. The first +will be a structure defining the driver operations: + +struct eth_driver_ops { + int (*init)(struct instance*, bd_t*); + int (*send)(struct instance*, void *packet, int length); + int (*recv)(struct instance*); + void (*halt)(struct instance*); + int (*mcast)(struct instance*, u32 ip, u8 set); + int (*write_hwaddr)(struct instance*); +}; + +Next, there'll be platform data which will be per-driver and will replace the +"priv" part of "struct eth_device". Last part will be the per-device core state. + +With regards to the PHY part of the API, the "struct phy_driver" is almost ready +to be used with the new driver model approach. The only change will be the +replacement of per-driver initialization functions and removal of +"phy_register()" function in favor or driver model approach. + +III) Analysis of in-tree drivers +-------------------------------- + + 1) drivers/net/4xx_enet.c + ------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 2) drivers/net/altera_tse.c + --------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 3) drivers/net/armada100_fec.c + ------------------------------ + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 4) drivers/net/at91_emac.c + -------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 5) drivers/net/ax88180.c + ------------------------ + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 6) drivers/net/ax88796.c + ------------------------ + + This file contains a components of the NE2000 driver, implementing only + different parts on the NE2000 clone AX88796. This being no standalone driver, + no conversion will be done here. + + 7) drivers/net/bfin_mac.c + ------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 8) drivers/net/calxedaxgmac.c + ----------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 9) drivers/net/cs8900.c + ----------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 10) drivers/net/davinci_emac.c + ------------------------------ + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 11) drivers/net/dc2114x.c + ------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 12) drivers/net/designware.c + ---------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 13) drivers/net/dm9000x.c + ------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 14) drivers/net/dnet.c + ---------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 15) drivers/net/e1000.c + ----------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 16) drivers/net/e1000_spi.c + --------------------------- + + Driver for the SPI bus integrated on the Intel E1000. This is not part of the + network stack. + + 17) drivers/net/eepro100.c + -------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 18) drivers/net/enc28j60.c + -------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 19) drivers/net/ep93xx_eth.c + ---------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 20) drivers/net/ethoc.c + ----------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 21) drivers/net/fec_mxc.c + ------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 22) drivers/net/fsl_mcdmafec.c + ------------------------------ + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 23) drivers/net/fsl_mdio.c + -------------------------- + + This file contains driver for FSL MDIO interface, which is not part of the + networking stack. + + 24) drivers/net/ftgmac100.c + --------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 25) drivers/net/ftmac100.c + -------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 26) drivers/net/greth.c + ----------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 27) drivers/net/inca-ip_sw.c + ---------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 28) drivers/net/ks8695eth.c + --------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 29) drivers/net/lan91c96.c + -------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 30) drivers/net/macb.c + ---------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 31) drivers/net/mcffec.c + ------------------------ + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 32) drivers/net/mcfmii.c + ------------------------ + + This file contains MII interface driver for MCF FEC. + + 33) drivers/net/mpc512x_fec.c + ----------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 34) drivers/net/mpc5xxx_fec.c + ----------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 35) drivers/net/mvgbe.c + ----------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 36) drivers/net/natsemi.c + ------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 37) drivers/net/ne2000_base.c + ----------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. This driver contains the core + implementation of NE2000, which needs a few external functions, implemented by + AX88796, NE2000 etc. + + 38) drivers/net/ne2000.c + ------------------------ + + This file implements external functions necessary for native NE2000 compatible + networking card to work. + + 39) drivers/net/netarm_eth.c + ---------------------------- + + This driver uses the old, legacy, network API and will either have to be + converted or removed. + + 40) drivers/net/netconsole.c + ---------------------------- + + This is actually an STDIO driver. + + 41) drivers/net/ns8382x.c + ------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 42) drivers/net/pcnet.c + ----------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 43) drivers/net/plb2800_eth.c + ----------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 44) drivers/net/rtl8139.c + ------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 45) drivers/net/rtl8169.c + ------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 46) drivers/net/sh_eth.c + ------------------------ + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 47) drivers/net/smc91111.c + -------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 48) drivers/net/smc911x.c + ------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 49) drivers/net/tsec.c + ---------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 50) drivers/net/tsi108_eth.c + ---------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 51) drivers/net/uli526x.c + ------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 52) drivers/net/vsc7385.c + ------------------------- + + This is a driver that only uploads firmware to a switch. This is not subject + of conversion. + + 53) drivers/net/xilinx_axi_emac.c + --------------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 54) drivers/net/xilinx_emaclite.c + --------------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. |