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20 lines
956 B
Plaintext
20 lines
956 B
Plaintext
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Broadcom introduced new bus as replacement for older SSB. It is based on AMBA,
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however from programming point of view there is nothing AMBA specific we use.
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Standard AMBA drivers are platform specific, have hardcoded addresses and use
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AMBA standard fields like CID and PID.
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In case of Broadcom's cards every device consists of:
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1) Broadcom specific AMBA device. It is put on AMBA bus, but can not be treated
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as standard AMBA device. Reading it's CID or PID can cause machine lockup.
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2) AMBA standard devices called ports or wrappers. They have CIDs (AMBA_CID)
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and PIDs (0x103BB369), but we do not use that info for anything. One of that
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devices is used for managing Broadcom specific core.
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Addresses of AMBA devices are not hardcoded in driver and have to be read from
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EPROM.
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In this situation we decided to introduce separated bus. It can contain up to
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16 devices identified by Broadcom specific fields: manufacturer, id, revision
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and class.
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