doc/README.bitbangMII

   1 This patch rewrites the miiphybb ( Bit-banged MII bus driver ) in order to
   2 support an arbitrary number of mii buses. This feature is useful when your
   3 board uses different mii buses for different phys and all (or a part) of these
   4 buses are implemented via bit-banging mode.
   5
   6 The driver requires that the following macros should be defined into the board
   7 configuration file:
   8
   9 CONFIG_BITBANGMII       - Enable the miiphybb driver
  10 CONFIG_BITBANGMII_MULTI - Enable the multi bus support
  11
  12 If the CONFIG_BITBANGMII_MULTI is not defined, the board's config file needs
  13 to define at least the following macros:
  14
  15 MII_INIT      - Generic code to enable the MII bus (optional)
  16 MDIO_DECLARE  - Declaration needed to access to the MDIO pin (optional)
  17 MDIO_ACTIVE   - Activate the MDIO pin as out pin
  18 MDIO_TRISTATE - Activate the MDIO pin as input/tristate pin
  19 MDIO_READ     - Read the MDIO pin
  20 MDIO(v)       - Write v on the MDIO pin
  21 MDC_DECLARE   - Declaration needed to access to the MDC pin (optional)
  22 MDC(v)        - Write v on the MDC pin
  23
  24 The previous macros make the driver compatible with the previous version
  25 (that didn't support the multi-bus).
  26
  27 When the CONFIG_BITBANGMII_MULTI is also defined, the board code needs to fill
  28 the bb_miiphy_buses[] array with a record for each required bus and declare
  29 the bb_miiphy_buses_num variable with the number of mii buses.
  30 The record (struct bb_miiphy_bus) has the following fields/callbacks (see
  31 miiphy.h for details):
  32
  33 char name[]            - The symbolic name that must be equal to the MII bus
  34                          registered name
  35 int (*init)()          - Initialization function called at startup time (just
  36                          before the Ethernet initialization)
  37 int (*mdio_active)()   - Activate the MDIO pin as output
  38 int (*mdio_tristate)() - Activate the MDIO pin as input/tristate pin
  39 int (*set_mdio)()      - Write the MDIO pin
  40 int (*get_mdio)()      - Read the MDIO pin
  41 int (*set_mdc)()       - Write the MDC pin
  42 int (*delay)()         - Delay function
  43 void *priv             - Private data used by board specific code
  44
  45 The board code will look like:
  46
  47 struct bb_miiphy_bus bb_miiphy_buses[] = {
  48  { .name = "miibus#1", .init = b1_init, .mdio_active = b1_mdio_active, ... },
  49  { .name = "miibus#2", .init = b2_init, .mdio_active = b2_mdio_active, ... },
  50  ...
  51 };
  52 int bb_miiphy_buses_num = sizeof(bb_miiphy_buses) /
  53                           sizeof(bb_miiphy_buses[0]);
  54
  55 2009 Industrie Dial Face S.p.A.
  56      Luigi 'Comio' Mantellini <luigi.mantellini@idf-hit.com>