[lkml]   [2005]   [Dec]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: [PATCH 2.6-git] SPI: add set_clock() to bitbang
    David Brownell wrote:

    >>No, suppose there're two devices behind the same SPI bus that have
    >>different clock constraints. As active SPI device change may well happen
    >>when each new message is processed, we'll need to set up clocks again
    >>for each message. Right?
    >Clock is coupled to chipselect/device. When the bus controller
    >switches to the other device, it updates the clock accordingly.
    Yeah, but chipselect is called on per-transfer basis what is likely to
    be redundant for clock setting.
    Per-message clock configuration is enough AFAIS.

    >How exactly that's done is system-specific. Many controllers
    >just have a register per chipselect, listing stuff like SPI mode,
    >clock divisor, and word size. So switching to that chipselect
    >kicks those in automatically ... devices ignore the clock unless
    >they've been selected.
    Hmm, usually clocks are configured for the bus not device.
    So, summarizing, you haven't convinced me yet. :)

    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to
    More majordomo info at
    Please read the FAQ at

     \ /
      Last update: 2005-12-23 08:14    [W:0.020 / U:3.360 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site