alistair23-linux/drivers/bcma
Rafał Miłecki dd4544f054 bgmac: driver for GBit MAC core on BCMA bus
BCMA is a Broadcom specific bus with devices AKA cores. All recent BCMA
based SoCs have gigabit ethernet provided by the GBit MAC core. This
patch adds driver for such a cores registering itself as a netdev. It
has been tested on a BCM4706 and BCM4718 chipsets.

In the kernel tree there is already b44 driver which has some common
things with bgmac, however there are many differences that has led to
the decision or writing a new driver:
1) GBit MAC cores appear on BCMA bus (not SSB as in case of b44)
2) There is 64bit DMA engine which differs from 32bit one
3) There is no CAM (Content Addressable Memory) in GBit MAC
4) We have 4 TX queues on GBit MAC devices (instead of 1)
5) Many registers have different addresses/values
6) RX header flags are also different

The driver in it's state is functional how, however there is of course
place for improvements:
1) Supporting more net_device_ops
2) SUpporting more ethtool_ops
3) Unaligned addressing in DMA
4) Writing separated PHY driver

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-09 23:37:03 -08:00
..
bcma_private.h Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2012-12-14 14:27:45 -08:00
core.c bcma: change delays to follow timers-howto guide 2012-09-28 13:54:02 -04:00
driver_chipcommon.c Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2012-12-14 14:27:45 -08:00
driver_chipcommon_nflash.c bcma: mark nflash if it is the boot flash 2012-10-19 15:52:37 -04:00
driver_chipcommon_pmu.c bgmac: driver for GBit MAC core on BCMA bus 2013-01-09 23:37:03 -08:00
driver_chipcommon_sflash.c bcma: add some more flash chips for serial flash 2012-10-19 15:52:39 -04:00
driver_gmac_cmn.c bcma: add trivial GBIT MAC COMMON driver 2012-07-12 15:27:18 -04:00
driver_gpio.c bcma: add GPIO driver 2012-11-21 21:55:52 +01:00
driver_mips.c bcma: mips: fix clearing device IRQ 2012-12-10 15:49:53 -05:00
driver_pci.c bcma: change delays to follow timers-howto guide 2012-09-28 13:54:02 -04:00
driver_pci_host.c bcma: handle return value of pci_assign_resource 2012-11-30 13:38:13 -05:00
host_pci.c bcma: suspend/resume callbacks should be conditionally compiled on CONFIG_PM_SLEEP 2012-10-29 15:19:31 -04:00
host_soc.c bcma: make some functions static 2012-08-10 15:26:52 -04:00
Kconfig bcma: add GPIO driver 2012-11-21 21:55:52 +01:00
main.c Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2012-12-14 14:27:45 -08:00
Makefile bcma: add GPIO driver 2012-11-21 21:55:52 +01:00
README
scan.c bcma: add missing iounmap on error path 2012-07-26 15:37:57 -04:00
scan.h bcma: fix typo - reading number of slave wrappers 2012-07-12 15:27:17 -04:00
sprom.c bcma: use fallback sprom if sprom on card was not valid 2012-10-19 15:52:53 -04:00
TODO

Broadcom introduced new bus as replacement for older SSB. It is based on AMBA,
however from programming point of view there is nothing AMBA specific we use.

Standard AMBA drivers are platform specific, have hardcoded addresses and use
AMBA standard fields like CID and PID.

In case of Broadcom's cards every device consists of:
1) Broadcom specific AMBA device. It is put on AMBA bus, but can not be treated
   as standard AMBA device. Reading it's CID or PID can cause machine lockup.
2) AMBA standard devices called ports or wrappers. They have CIDs (AMBA_CID)
   and PIDs (0x103BB369), but we do not use that info for anything. One of that
   devices is used for managing Broadcom specific core.

Addresses of AMBA devices are not hardcoded in driver and have to be read from
EPROM.

In this situation we decided to introduce separated bus. It can contain up to
16 devices identified by Broadcom specific fields: manufacturer, id, revision
and class.