On 27/06/2016 at 18:15:17 +0300, Sergei Ianovich wrote : > > How do yo currently select microwire mode for PX270? > > I didn't say I use PXA270 to drive this RTC. I just say it is possible. > The driver needs to set bits 5:4 of SSCR0_1/2/3 register to 0b10. > Microwire mode will be selected for a built-in SPI port. All bitbanging > will be done by the chip, the driver will just need to set up DMA > transfer. This is an example of a pretty sophisticated hardware > controller. > > I actually use a simple software controller in LP8841. The driver is > in drivers/spi/spi-lp8841-rtc.c. Ok, seeing that, now I'm thinking that switching the ds1302 driver to spi was a mistake and bitbanging in the driver was the right thing to do. What you introduced are two drivers instead of one and the abstraction is actually getting worse. So I'm thinking the best solution is to write a proper driver bitbanging microwire (maybe in the SPI subsystem) that everybody could use, including old architectures. Else, I may as well revert to the previous driver. -- Alexandre Belloni, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
