linux-sg2042/drivers/bcma
Hauke Mehrtens 32998cc96a bcma: use fallback sprom if no on chip sprom is available
bcma should check for a fallback sprom every time it can not find a
sprom on the card itself or a normal external sprom mapped into the
memory of the chip. When otp sprom support was introduced it tried to
read out the sprom from the wireless chip also if no otp sprom was
available. This caused a Data bus error in bcma_sprom_get() when
reading out the sprom for the SoC.

This fixes a regression introduced in commit:

commit 10d8493cd9
Author: Arend van Spriel <arend@broadcom.com>
Date:   Tue Mar 6 15:50:48 2012 +0100

    bcma: add support for on-chip OTP memory used for SPROM storage

This patch was tested on a Netgear WNDR3400 (Broadcom BCM4718 SoC).

Reported-by: Nick Bowler <nbowler@elliptictech.com>
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Acked-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-16 13:32:01 -04:00
..
Kconfig bcma: fix build error on MIPS; implicit pcibios_enable_device 2012-04-10 14:13:30 -04:00
Makefile bcma: add mips driver 2011-08-08 14:29:26 -04:00
README bcma: add Broadcom specific AMBA bus driver 2011-05-10 15:54:54 -04:00
TODO bcma: add Broadcom specific AMBA bus driver 2011-05-10 15:54:54 -04:00
bcma_private.h bcma: add PCIe host controller 2012-02-06 14:53:04 -05:00
core.c bcma: fix implicit use of export.h contents 2011-10-31 19:32:02 -04:00
driver_chipcommon.c bcma: fix implicit use of export.h contents 2011-10-31 19:32:02 -04:00
driver_chipcommon_pmu.c bcma: silence PMU warning for BCM4331 2012-03-07 13:56:37 -05:00
driver_mips.c bcma: get CPU clock 2011-08-08 14:29:29 -04:00
driver_pci.c bcma: add PCIe host controller 2012-02-06 14:53:04 -05:00
driver_pci_host.c bcma: fix build error on MIPS; implicit pcibios_enable_device 2012-04-10 14:13:30 -04:00
host_pci.c bcma: make some functions __devinit 2012-02-06 14:53:03 -05:00
host_soc.c bcma: add SOC bus 2011-08-08 14:29:25 -04:00
main.c bcma: export bcma_find_core 2012-03-05 15:20:50 -05:00
scan.c Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless 2012-02-15 16:24:37 -05:00
scan.h bcma: add Broadcom specific AMBA bus driver 2011-05-10 15:54:54 -04:00
sprom.c bcma: use fallback sprom if no on chip sprom is available 2012-04-16 13:32:01 -04:00

README

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.