Re: [RFC 0/2] Add hci_smd driver

[Kumar Gala <galak@codeaurora.org>]

On Feb 11, 2014, at 10:23 AM, Lukasz Rymanowski <lukasz.rymanowski@tieto.com> wrote:

> Hi
> 
> On 7 February 2014 12:35, Lukasz Rymanowski <lukasz.rymanowski@tieto.com> wrote:
>> Hello,
>> 
>> This is a try (long shoot) to upstream hci shared memory driver (hci_smd)
>> which is used on Qualcomm platforms and BT chips.
>> 
>> To make it build with upstream tree I had to introduce some simple SMD API.
>> The idea here is that since SMD channel is represented by platform device
>> (as it is done in mach-msm),
>> then platfrom_data contains smd_data which contains API for that channel.
>> 
>> Writing this SMD API I was inspired with MSM-SMD and since I'm not an expert
>> in this area I'm asking for comments here.
>> 
>> Maybe instead of SMD API I made, I should expose functions like smd_open(), smd_write()
>> etc. something similar how sdio does, and  just deliver to upstream dummy device
>> implementing this SMD API?
>> 
>> Other options I was considering is to implement  module inside mach-msm which
>> would handle registering SMD BT Channels and when it is done, it would register
>> new platform device like "smd-bt". Then I could move smd.h to some bluetooth includes
>> (althought don't now where at the moment) and hci_smd would register driver for "smd-bt"
>> In this case I would also could rid of one static variable I have now in hci_smd
>> 
>> Comments on those options are welcome.
>> 
>> Anyway, Hci_smd is based on one of the older version of this driver found in msm kernel
>> branch, so there are no wakelocks as in new version and also workqueues are used
>> instead of takslet.
>> 
>> Since SMD expose two channels, one for CMD/EVENT and one for ACL Data I decide to
>> do separate worqueues for this. This is to make sure that ACL data never blocks EVENT
>> packages
>> 
> 
> Adding linux-arm-msm group for comments on SMD API.
> 
> BR
> Lukasz

What chip/SoC/board are you trying to get bluetooth support on?

- k

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