From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shawn Guo Subject: Re: [PATCH 1/2] spi: imx: set correct chip_select in platform setup Date: Mon, 20 Mar 2017 15:38:16 +0800 Message-ID: <20170320073815.GD3443@dragon> References: <1489726983-17706-1-git-send-email-gerg@linux-m68k.org> <1489726983-17706-2-git-send-email-gerg@linux-m68k.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, fabio.estevam-3arQi8VN3Tc@public.gmane.org, kernel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org To: Greg Ungerer Return-path: Content-Disposition: inline In-Reply-To: <1489726983-17706-2-git-send-email-gerg-Td1EMuHUCqxL1ZNQvxDV9g@public.gmane.org> Sender: linux-spi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: On Fri, Mar 17, 2017 at 03:03:02PM +1000, Greg Ungerer wrote: > Some platform based configuration setup of spi-imx SPI devices does > not set the "chip_select" to the actual hardware chip select used. > This works because the cs_gpio mapping that is associated with this > platform setup maps the chip_select offset used to the appropriate > hardware chip select. The spi-imx driver uses the chip_select as an > index into the cs_gpio array and ultimately gets the correct hardware > chip select for its hardware setup. > > The motivation is to be able to eventually modify the spi-imx code to > use the "chip_select" directly for harwdare setup instead of indirectly > via the cs_gpio mapping array. > > This change only affects platforms using the hardware chip select > addressing method for their SPI devices (sometimes called native chip > select). The majority of devices using the spi-imx driver use the GPIO > addressing method. > > The change to use the correct "chip_select" is strait forward. But the > cs_gpio mapping arrary also needs to be modifed to match that change. In > simple terms the cs_gpio mapping should always have the hardware chip > select number at its same index offset. > > There is no functional change with these patches. The three affected > platforms should work exactly as before. However I don't have any of > these platforms (or access to them) and so I can't test them. So this > patch is compile tested only. > > Signed-off-by: Greg Ungerer The subject prefix should be 'ARM: imx: ...'. Since the patch can go independently, I fix up the prefix and applied the patch. Thanks. Shawn -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html