On 9 May 2012 22:32, Mark Brown <broonie@xxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > On Wed, May 09, 2012 at 10:13:28PM +0800, Thomas Abraham wrote: >> On 9 May 2012 17:07, Mark Brown <broonie@xxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote: >> > On Wed, May 09, 2012 at 03:34:54AM +0530, Thomas Abraham wrote: > >> >> +- gpios: The gpio specifier for clock, mosi and miso interface lines (in no >> >> + particular order). The format of the gpio specifier depends on the gpio >> >> + controller. > >> > This seems odd... This isn't a bitbanging controller, and surely the >> > driver will need to know which signal is which? I suspect this is >> > actually for pinmux rather than to identify the signals but that should >> > at least be made clear and really should be being done using the pinmux >> > API. > >> The driver retrieves the list of gpio's that it is allowed to use. The >> gpio numbers for miso, mosi and clk are mandatory but the order in >> which they are specified is not important since the driver never needs >> to which gpio is which interface line. I agree the pinmux api should >> be used here, but the call to pinmux api would be a incremental change >> here, not changing the code this patch is adding. > > I'd suggest just specifying the order - someone might want to use it > later for some reason and it's not really a hardship for someone to use > it. Avoids any "how does that work?" questions like I had. Ok. I will add the order of the gpios as you have suggested. > >> >> + - samsung,spi-cs-gpio: A gpio specifier that specifies the gpio line used as >> >> + the slave select line by the spi controller. The format of the gpio >> >> + specifier depends on the gpio controller. > >> > We should really have a binding for this at the SPI level (and ideally >> > some code to manage setting the GPIO too) - it's pretty common to use a >> > GPIO as /CS. > >> The existing implementations vary in the way the nCS gpio lines are >> specified. For some controllers, the nCS gpio's are included in the >> spi device node whereas in this implementation, the nCS gpio is listed >> in the spi slave device node. > > Yeah, I know. I'm saying we should try to come up with a binding for > this that can be used by new SPI contollers going forward so things are > consistent. Ok. For this patch series, I will continue with the samsung specific binding for the nCS line. Thanks, Thomas. -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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