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| author | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2011-07-27 09:54:47 +0200 |
|---|---|---|
| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2011-07-27 09:54:47 +0200 |
| commit | aa7eb8e78d8ecd6cd0475d86ea8385ff9cb47ece (patch) | |
| tree | 3f9e98fadd5124fb05e8f6f9b06aa23698d4f215 /drivers/bcma/README | |
| parent | Input: sh_keysc - fix compile warning (diff) | |
| parent | Input: synaptics - fix reporting of min coordinates (diff) | |
| download | linux-aa7eb8e78d8ecd6cd0475d86ea8385ff9cb47ece.tar.xz linux-aa7eb8e78d8ecd6cd0475d86ea8385ff9cb47ece.zip | |
Merge branch 'next' into for-linus
Diffstat (limited to 'drivers/bcma/README')
| -rw-r--r-- | drivers/bcma/README | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/drivers/bcma/README b/drivers/bcma/README new file mode 100644 index 000000000000..f7e7ce46c603 --- /dev/null +++ b/drivers/bcma/README @@ -0,0 +1,19 @@ +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. |