[PATCH 1/6] spi-imx: add CSPI and eCSPI support for i.MX51 MCU
Baruch Siach
baruch at tkos.co.il
Thu Sep 2 13:29:09 EDT 2010
Hi Lothar,
On Thu, Sep 02, 2010 at 05:11:56PM +0200, Lothar Waßmann wrote:
> > > - if (cpu_is_mx25() || cpu_is_mx31() || cpu_is_mx35()) {
> > > + /* i.MX51 has two eCSPI and one CSPI controllers, eCSPI controllers are
> > > + * not compatible with existing SPI controllers on other i.MX platforms,
> > > + * while CSPI controller is 100% compatible with the one on the i.MX35.
> > > + * We set the platform device id to 2 for this CSPI at i.MX51 board init
> > > + * level to distinguish it from two eCSPI controllers.
> > > + */
> > This comment is missing in Sascha's driver. I like it.
> > BTW, I'd like to make use of platform ids in this driver. This would
> > make this ugly "on imx51 id2 is a cspi" distinction unnecessary.
> >
> > > + if (cpu_is_mx25() || cpu_is_mx31() || cpu_is_mx35() ||
> > > + (cpu_is_mx51() && (pdev->id == 2))) {
> I'd prefer a flag in the platform_data that tells the driver to act as
> an eCSPI driver. This way the information about eCSPI or not would be
> where it belongs (in the arch specific code).
But this also increases the size of driver code, since the compiler can
resolve cpu_is_* at compile time, and drop the dead code. Maybe an is_ecspi
macro will make the above code clearer.
baruch
--
~. .~ Tk Open Systems
=}------------------------------------------------ooO--U--Ooo------------{=
- baruch at tkos.co.il - tel: +972.2.679.5364, http://www.tkos.co.il -
More information about the linux-arm-kernel
mailing list