From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Garry Subject: Re: [PATCH v2 2/3] spi: Add HiSilicon v3xx SPI NOR flash controller driver Date: Fri, 10 Jan 2020 11:55:37 +0000 Message-ID: References: <1575900490-74467-1-git-send-email-john.garry@huawei.com> <1575900490-74467-3-git-send-email-john.garry@huawei.com> <0dc5cb2e-b765-9e13-b05e-9e3c835c5985@huawei.com> <20200109212842.GK3702@sirena.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Cc: , , , , , , , , To: Mark Brown Return-path: In-Reply-To: <20200109212842.GK3702-GFdadSzt00ze9xe1eoZjHA@public.gmane.org> Content-Language: en-US Sender: linux-spi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: On 09/01/2020 21:28, Mark Brown wrote: > On Thu, Jan 09, 2020 at 03:54:00PM +0000, John Garry wrote: > >> From checking acpi_spi_add_resource() or anywhere else, I cannot see how >> SPI_RX_DUAL or the others are set for spi_device.mode. What am I missing? >> Are these just not supported yet for ACPI? Or should the spi-nor code not be >> relying on this since we should be able to get this info from the SPI NOR >> part? > Hi Mark, > I'm not aware of any work on integrating this sort of stuff into ACPI > platforms so I think it's just not yet supported in ACPI. I'm not > really sure what would be idiomatic for ACPI, figuring it out from what > the part supports might well be idiomatic there though I don't know how > common it is for people not to wire up all the data lines even if both > controller and device support wider transfers. OK, so I guess that is why we require the width property from the FW and can't blindly rely on SFDP. I've got a horrible > feeling that the idiomatic thing is a combination of that and a bunch of > per-device quirks. There may be a spec I'm not aware of though I'd be a > bit surprised. > I'm not sure on that. I don't see anything in the ACPI spec. I will note that PRP0001+"jedec,spi-nor" compatible DSD seems to be the defacto method to describe the SPI NOR-compat part for ACPI - that's what I'm using. We could add properties there, but that seems improper. I'll continue to look.... Thanks, John