Messages in this thread | | | Date | Tue, 20 Dec 2005 21:02:24 +0300 | From | Vitaly Wool <> | Subject | Re: [PATCH/RFC] SPI: async message handing library update |
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Hi David --
just a cuple of notes here and below...
General one: how is it supposed to set SPI bus clock in this model? I guess that the only option is to set it in txrx_*. That is not optimal since it means setting clock for each transfer which is not an optimal solution, better have a function (bitbang->set_clock or whatever) )to set clock per message.
> if (!spi->max_speed_hz) > spi->max_speed_hz = 500 * 1000; > > /* nsecs = max(50, (clock period)/2), be optimistic */ > cs->nsecs = (1000000000/2) / (spi->max_speed_hz); > if (cs->nsecs < 50) > cs->nsecs = 50; > > Suggest not to hardcode values here.
> /* set up default clock polarity, and activate chip */ > if (!chipselect) { > bitbang->chipselect(spi, 1); > ndelay(nsecs); > > Suggest special enum/define for chipselect value.
> /* protocol tweaks before next transfer */ > if (t->delay_usecs) > udelay(t->delay_usecs); > > Suggest nsecs here as well.
Generic note: haven't tested that with DMA, will have more comments prolly... Another one: I just feel comfortabel with using 'bitbang' term for the variety of SPI stuff which this library suits.
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