Re: [RFC 04/25] spi: gpio: Implement LSB First bitbang support
From: Andreas Färber <afaerber@suse.de>
Date: 2019-12-12 21:08:28
Also in:
linux-leds, linux-spi, lkml
Am 12.12.19 um 18:19 schrieb Mark Brown:
On Thu, Dec 12, 2019 at 04:14:59PM +0100, Andreas Färber wrote:quoted
Am 12.12.19 um 09:40 schrieb Geert Uytterhoeven:quoted
On Thu, Dec 12, 2019 at 4:41 AM Andreas Färber [off-list ref] wrote:quoted
Add support for slave DT property spi-lsb-first, i.e., SPI_LSB_FIRST mode.quoted
quoted
quoted
Duplicate the inline helpers bitbang_txrx_be_cpha{0,1} as LE versions. Make checkpatch.pl happy by changing "unsigned" to "unsigned int".Separate patch for this?
For the checkpatch cleanup? Or helpers preparation vs. spi-gpio.c usage?
quoted
So from that angle I don't see a better way than either duplicating the functions or using some macro magic to #include the header twice. If we wanted to go down that path, we could probably de-duplicate the existing two functions, too, but I was trying to err on the cautious side, since I don't have setups to test all four code paths myself (and a ton of more relevant but less fun patches to flush out ;)).Yeah, I don't think there's any great options here with the potential performance issues - probably the nicest thing would be to autogenerate lots of variants but I think that's far more trouble than it's worth.
Maybe add another code comment to revisit that idea later then? Thanks, Andreas -- SUSE Software Solutions Germany GmbH Maxfeldstr. 5, 90409 Nürnberg, Germany GF: Felix Imendörffer HRB 36809 (AG Nürnberg) _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel