From mboxrd@z Thu Jan 1 00:00:00 1970 From: mans@mansr.com (=?iso-8859-1?Q?M=E5ns_Rullg=E5rd?=) Date: Wed, 13 Jan 2016 02:07:37 +0000 Subject: [PATCH] spi: atmel: improve internal vs gpio chip-select choice In-Reply-To: <5694BE36.7060702@atmel.com> (Nicolas Ferre's message of "Tue, 12 Jan 2016 09:49:58 +0100") References: <1452211907-16074-1-git-send-email-mans@mansr.com> <5693C9A3.9040403@atmel.com> <5694BE36.7060702@atmel.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Nicolas Ferre writes: > Le 11/01/2016 16:43, M?ns Rullg?rd a ?crit : >> Nicolas Ferre writes: >> >>> Le 08/01/2016 01:11, Mans Rullgard a ?crit : >>>> The driver currently chooses between internal chip-select or gpio >>>> based on the existence of the cs-gpios DT property which fails on >>>> non-DT systems and also enforces the same choice for all devices. >>> >>> Well, I fear that such a per-device choice may impact further the driver >>> than just moving a field from one structure to another... >> >> Could you please elaborate? > > Well, the first thing that comes to my mind is that the DT property may > need to be to the SPI device node and not the controller anymore, for a > need of coherency. > That would imply modifying the binding and I don't want that for such an > useless "improvement". > >>> Moreover, I have the feeling that it was not the objective of this >>> patch. >> >> Your feeling is mistaken. If it's somehow impossible to mix CS types, >> please explain why. > > Please only fix the avr32 issue with CS gpio selection that I admit we > have. I don't need nor want to mix CS types: it just doesn't make sense > to allow it. There's also this comment in spi.h regarding struct spi_master: * @cs_gpios: Array of GPIOs to use as chip select lines; one per CS * number. Any individual value may be -ENOENT for CS lines that * are not GPIOs (driven by the SPI controller itself). -- M?ns Rullg?rd