From mboxrd@z Thu Jan 1 00:00:00 1970 From: tudor.ambarus@microchip.com (Tudor Ambarus) Date: Tue, 26 Jun 2018 17:44:26 +0300 Subject: [RFC PATCH 1/2] spi: Add QuadSPI driver for Atmel SAMA5D2 In-Reply-To: <20180622093905.62a3b936@bbrezillon> References: <20180618162124.21749-1-bugalski.piotr@gmail.com> <20180618162124.21749-2-bugalski.piotr@gmail.com> <20180621233321.0f25f572@bbrezillon> <20180622093905.62a3b936@bbrezillon> Message-ID: <455adb76-530a-1fd5-303c-cfa158ad7870@microchip.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi, Piotr, General things to consider for the limitation in performance: - is the serial flash memory operating in Quad SPI? - QSCLK should be as high as possible - transfer delays - I checked them, they have default values, we should be good. - use DMA, as you suggested On 06/22/2018 10:39 AM, Boris Brezillon wrote: > [...] > >>>> +/* >>>> + * Atmel SAMA5D2 QuadSPI driver. >>>> + * >>>> + * Copyright (C) 2018 Cryptera A/S >>> >>> A non-negligible portion of this code has been copied from the existing >>> driver. Please keep the existing copyright (you can still add Cryptera's >>> one). >>> >> >> Technically this driver were written from scratch, with spi-fsl-qspi >> as example of new interface. Hence the name and code structure. >> But it's the same peripheral as Atmel's driver uses so code looks >> similar. I can unify the code to make comparsion even simpler and >> then update copyright. > > Hm, ok. Some constructs really looked like they were copied > from the old driver, hence my comment. I'll let Nicolas give his > opinion on this aspect. This driver will be a conversion of the legacy one to the spi-mem interface. I would keep the legacy copyright and add Cryptera's below, as Boris suggested. [...] >>>> +#define QSPI_SR_CMD_COMPLETED (QSPI_SR_INSTRE | QSPI_SR_CSR) >>> >>> Do you really to wait for both INSTRE and CSR to consider the command >>> as complete? >>> >> >> This part were really copied from Atmel driver. I wasn't sure so I >> used tested solution. > > Okay. I guess that's a question for Cyrille and/or Tudor then. We have to wait for both INSTRE and CSR. Best, ta