From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.6 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1C7A1C04ABB for ; Thu, 13 Sep 2018 14:26:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B514B20861 for ; Thu, 13 Sep 2018 14:26:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=lechnology.com header.i=@lechnology.com header.b="gf2ygXnO" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B514B20861 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lechnology.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727726AbeIMTgh (ORCPT ); Thu, 13 Sep 2018 15:36:37 -0400 Received: from vern.gendns.com ([206.190.152.46]:46517 "EHLO vern.gendns.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726741AbeIMTgg (ORCPT ); Thu, 13 Sep 2018 15:36:36 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lechnology.com; s=default; h=Content-Transfer-Encoding:Content-Type: In-Reply-To:MIME-Version:Date:Message-ID:From:References:Cc:To:Subject:Sender :Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=IZZgvUx9RJZ8uvSOM70gTpEseE17YXDOS1vzz42g9CM=; b=gf2ygXnOlv8/yenUmgXA4zOvbc E9zdQFFXvs0tSTeGHaKd6y/CGqfyozLC6bZmXZO8tbr6/Vlc9CAmdZ6BXVoZdtD4lksVV2dtON+JZ A2aR8FXrMexIF//fCeWF5Bepv5JESbGCFXsWzvt3GHkchtR6PomUo4DpkK4NEe01/zcLhQMqyRKA+ sdImI08SfZCe1Y94DXzdgfl2DHndkZ3WJ3AKm3c0Z0z3g95DqvUreBl0r0a6W28iwXj0+BtinZIVp /muSLehWvUgf4s9f90vdZRlDxs/fxOlZdaGNhqGgIYTliWo1OLJbCYRvahsvAHGnij2VEVSjkgGgY Qo8/6T/A==; Received: from 108-198-5-147.lightspeed.okcbok.sbcglobal.net ([108.198.5.147]:42168 helo=[192.168.0.134]) by vern.gendns.com with esmtpsa (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.91) (envelope-from ) id 1g0Sa0-00BuOP-Jo; Thu, 13 Sep 2018 10:26:48 -0400 Subject: Re: [PATCH v2 4/4] spi: spi-davinci: Add support for SPI_CS_WORD To: Geert Uytterhoeven Cc: linux-spi , linux-iio@vger.kernel.org, Jonathan Cameron , Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald , Mark Brown , Linux Kernel Mailing List References: <20180913003920.30600-1-david@lechnology.com> <20180913003920.30600-5-david@lechnology.com> From: David Lechner Message-ID: Date: Thu, 13 Sep 2018 09:26:48 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - vern.gendns.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - lechnology.com X-Get-Message-Sender-Via: vern.gendns.com: authenticated_id: davidmain+lechnology.com/only user confirmed/virtual account not confirmed X-Authenticated-Sender: vern.gendns.com: davidmain@lechnology.com X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/13/2018 08:44 AM, Geert Uytterhoeven wrote: > Hi David, > > On Thu, Sep 13, 2018 at 2:40 AM David Lechner wrote: >> This adds support for the SPI_CS_WORD flag to the TI DaVinci SPI >> driver. This mode can be used as long as we are using the hardware >> chip select and not a GPIO chip select. >> >> Signed-off-by: David Lechner >> --- >> drivers/spi/spi-davinci.c | 11 ++++++++--- >> 1 file changed, 8 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/spi/spi-davinci.c b/drivers/spi/spi-davinci.c >> index d502cf504deb..8f7dcbc53c57 100644 >> --- a/drivers/spi/spi-davinci.c >> +++ b/drivers/spi/spi-davinci.c >> @@ -230,7 +230,8 @@ static void davinci_spi_chipselect(struct spi_device *spi, int value) >> !(spi->mode & SPI_CS_HIGH)); >> } else { >> if (value == BITBANG_CS_ACTIVE) { >> - spidat1 |= SPIDAT1_CSHOLD_MASK; >> + if (!(spi->mode & SPI_CS_WORD)) >> + spidat1 |= SPIDAT1_CSHOLD_MASK; >> spidat1 &= ~(0x1 << chip_sel); >> } >> } >> @@ -440,8 +441,12 @@ static int davinci_spi_setup(struct spi_device *spi) >> return retval; >> } >> >> - if (internal_cs) >> + if (internal_cs) { >> set_io_bits(dspi->base + SPIPC0, 1 << spi->chip_select); >> + } else if (spi->mode & SPI_CS_WORD) { >> + dev_err(&spi->dev, "SPI_CS_WORD can't be use with GPIO CS\n"); >> + return -EINVAL; > > Does the SPI core fall back to splitting the transfer in this case? Hmm... it doesn't look like it. I suppose it might be best to modify the SPI core to say: if ((spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) || gpio_is_valid(spi->cs_gpio)) { instead of: if ((spi->mode & SPI_CS_WORD) && !(ctlr->mode_bits & SPI_CS_WORD)) { Then we could drop the error above. > >> + } > > Gr{oetje,eeting}s, > > Geert > > -- > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org > > In personal conversations with technical people, I call myself a hacker. But > when I'm talking to journalists I just say "programmer" or something like that. > -- Linus Torvalds >