[U-Boot] [PATCH 05/14] dm: Add networking subsystem analysis

Marek Vasut
2012-08-08T11:42:21Z

Signed-off-by: Marek Vasut <marex@denx.de>
---
doc/driver-model/UDM-net.txt | 434 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 434 insertions(+)
create mode 100644 doc/driver-model/UDM-net.txt

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.
--
1.7.10.4