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authorLuigi 'Comio' Mantellini <luigi.mantellini@idf-hit.com>2009-10-10 12:42:20 +0200
committerBen Warren <biggerbadderben@gmail.com>2009-10-10 23:16:53 -0700
commit4ba31ab33ac824635fcb49ac609070a9ebcab7f0 (patch)
tree4465058cdcbc4e554cd9e054385e1c2d67763866 /doc
parentcd77dd109c4a439519a78c32eddc42bdebc7a61f (diff)
Rewrite the miiphybb (Bit-banged MII bus driver) in order to support an arbitrary number of mii buses.
This feature is useful when your board uses different mii buses for different phys and all (or a part) of these buses are implemented via bit-banging mode. The driver requires that the following macros should be defined into the board configuration file: CONFIG_BITBANGMII - Enable the miiphybb driver CONFIG_BITBANGMII_MULTI - Enable the multi bus support If the CONFIG_BITBANGMII_MULTI is not defined, the board's config file needs to define at least the following macros: MII_INIT - Generic code to enable the MII bus (optional) MDIO_DECLARE - Declaration needed to access to the MDIO pin (optional) MDIO_ACTIVE - Activate the MDIO pin as out pin MDIO_TRISTATE - Activate the MDIO pin as input/tristate pin MDIO_READ - Read the MDIO pin MDIO(v) - Write v on the MDIO pin MDC_DECLARE - Declaration needed to access to the MDC pin (optional) MDC(v) - Write v on the MDC pin The previous macros make the driver compatible with the previous version (that didn't support the multi-bus). When the CONFIG_BITBANGMII_MULTI is also defined, the board code needs to fill the bb_miiphy_buses[] array with a record for each required bus and declare the bb_miiphy_buses_num variable with the number of mii buses. The record (struct bb_miiphy_bus) has the following fields/callbacks (see miiphy.h for details): char name[] - The symbolic name that must be equal to the MII bus registered name int (*init)() - Initialization function called at startup time (just before the Ethernet initialization) int (*mdio_active)() - Activate the MDIO pin as output int (*mdio_tristate)() - Activate the MDIO pin as input/tristate pin int (*set_mdio)() - Write the MDIO pin int (*get_mdio)() - Read the MDIO pin int (*set_mdc)() - Write the MDC pin int (*delay)() - Delay function void *priv - Private data used by board specific code The board code will look like: struct bb_miiphy_bus bb_miiphy_buses[] = { { .name = miibus#1, .init = b1_init, .mdio_active = b1_mdio_active, ... }, { .name = miibus#2, .init = b2_init, .mdio_active = b2_mdio_active, ... }, ... int bb_miiphy_buses_num = sizeof(bb_miiphy_buses) / sizeof(bb_miiphy_buses[0]); Signed-off-by: Luigi 'Comio' Mantellini <luigi.mantellini@idf-hit.com> Signed-off-by: Ben Warren <biggerbadderben@gmail.com>
Diffstat (limited to 'doc')
-rw-r--r--doc/README.bitbangMII56
1 files changed, 56 insertions, 0 deletions
diff --git a/doc/README.bitbangMII b/doc/README.bitbangMII
new file mode 100644
index 0000000000..edd085630f
--- /dev/null
+++ b/doc/README.bitbangMII
@@ -0,0 +1,56 @@
+This patch rewrites the miiphybb ( Bit-banged MII bus driver ) in order to
+support an arbitrary number of mii buses. This feature is useful when your
+board uses different mii buses for different phys and all (or a part) of these
+buses are implemented via bit-banging mode.
+
+The driver requires that the following macros should be defined into the board
+configuration file:
+
+CONFIG_BITBANGMII - Enable the miiphybb driver
+CONFIG_BITBANGMII_MULTI - Enable the multi bus support
+
+If the CONFIG_BITBANGMII_MULTI is not defined, the board's config file needs
+to define at least the following macros:
+
+MII_INIT - Generic code to enable the MII bus (optional)
+MDIO_DECLARE - Declaration needed to access to the MDIO pin (optional)
+MDIO_ACTIVE - Activate the MDIO pin as out pin
+MDIO_TRISTATE - Activate the MDIO pin as input/tristate pin
+MDIO_READ - Read the MDIO pin
+MDIO(v) - Write v on the MDIO pin
+MDC_DECLARE - Declaration needed to access to the MDC pin (optional)
+MDC(v) - Write v on the MDC pin
+
+The previous macros make the driver compatible with the previous version
+(that didn't support the multi-bus).
+
+When the CONFIG_BITBANGMII_MULTI is also defined, the board code needs to fill
+the bb_miiphy_buses[] array with a record for each required bus and declare
+the bb_miiphy_buses_num variable with the number of mii buses.
+The record (struct bb_miiphy_bus) has the following fields/callbacks (see
+miiphy.h for details):
+
+char name[] - The symbolic name that must be equal to the MII bus
+ registered name
+int (*init)() - Initialization function called at startup time (just
+ before the Ethernet initialization)
+int (*mdio_active)() - Activate the MDIO pin as output
+int (*mdio_tristate)() - Activate the MDIO pin as input/tristate pin
+int (*set_mdio)() - Write the MDIO pin
+int (*get_mdio)() - Read the MDIO pin
+int (*set_mdc)() - Write the MDC pin
+int (*delay)() - Delay function
+void *priv - Private data used by board specific code
+
+The board code will look like:
+
+struct bb_miiphy_bus bb_miiphy_buses[] = {
+ { .name = "miibus#1", .init = b1_init, .mdio_active = b1_mdio_active, ... },
+ { .name = "miibus#2", .init = b2_init, .mdio_active = b2_mdio_active, ... },
+ ...
+};
+int bb_miiphy_buses_num = sizeof(bb_miiphy_buses) /
+ sizeof(bb_miiphy_buses[0]);
+
+2009 Industrie Dial Face S.p.A.
+ Luigi 'Comio' Mantellini <luigi.mantellini@idf-hit.com>