From patchwork Thu Dec 12 03:39:31 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Andreas_F=C3=A4rber?= X-Patchwork-Id: 11286901 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 952FD930 for ; Thu, 12 Dec 2019 03:41:26 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 704F8214D8 for ; Thu, 12 Dec 2019 03:41:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="sNRbhEOg" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 704F8214D8 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=2zYqMkR76Ak8mJrViHp+TfxUXypdQLZoSxzwUJ5yDY4=; b=sNRbhEOgNqkJCd kAP2a22sQsDVF1qGkJ8/vUGF5br+YRO34lauMIPNE03ymoMxqrRlOmTMzU3To9GDXxIRms+WhC71Y Web54AbmNqaPuEBNmyUfvvJG9DdsPhLqrnemXGRL5i+Bzg7N9WEW57bOcJt8B+esJky7jIKFFMRO5 uDGUjkvurtW1oRNnVtUW/VKS3QweQpsnZiN1oVoLXlfvkodo04klChFToGBfBsyBYPoFPh2gJx/Tv FhJgWnz+R300tGH7qvqX9xQOWBVMRk+Vr+drO/Hw56R1TYgIqPVfEE7+Vxj88oXOYxZhgeSt2FxFW bYxi7gfCxQknC6+EKYkQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1ifFLw-0002fd-Fu; Thu, 12 Dec 2019 03:41:24 +0000 Received: from mx2.suse.de ([195.135.220.15] helo=mx1.suse.de) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1ifFKZ-0000NW-6u; Thu, 12 Dec 2019 03:40:01 +0000 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id ECAB9AE40; Thu, 12 Dec 2019 03:39:57 +0000 (UTC) From: =?utf-8?q?Andreas_F=C3=A4rber?= To: linux-realtek-soc@lists.infradead.org, linux-leds@vger.kernel.org Subject: [RFC 04/25] spi: gpio: Implement LSB First bitbang support Date: Thu, 12 Dec 2019 04:39:31 +0100 Message-Id: <20191212033952.5967-5-afaerber@suse.de> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20191212033952.5967-1-afaerber@suse.de> References: <20191212033952.5967-1-afaerber@suse.de> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191211_193959_535474_18184438 X-CRM114-Status: GOOD ( 13.14 ) X-Spam-Score: -2.3 (--) X-Spam-Report: SpamAssassin version 3.4.2 on bombadil.infradead.org summary: Content analysis details: (-2.3 points) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at https://www.dnswl.org/, medium trust [195.135.220.15 listed in list.dnswl.org] 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.0 SPF_PASS SPF: sender matches SPF record X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org, Mark Brown , Jacek Anaszewski , Pavel Machek , =?utf-8?q?Andreas_F=C3=A4rber?= , linux-arm-kernel@lists.infradead.org, Dan Murphy Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org Add support for slave DT property spi-lsb-first, i.e., SPI_LSB_FIRST mode. Duplicate the inline helpers bitbang_txrx_be_cpha{0,1} as LE versions. Make checkpatch.pl happy by changing "unsigned" to "unsigned int". Conditionally call them from all the spi-gpio txrx_word callbacks. Signed-off-by: Andreas Färber --- drivers/spi/spi-bitbang-txrx.h | 68 ++++++++++++++++++++++++++++++++++++++++-- drivers/spi/spi-gpio.c | 42 ++++++++++++++++++++------ 2 files changed, 99 insertions(+), 11 deletions(-) diff --git a/drivers/spi/spi-bitbang-txrx.h b/drivers/spi/spi-bitbang-txrx.h index ae61d72c7d28..999a89325325 100644 --- a/drivers/spi/spi-bitbang-txrx.h +++ b/drivers/spi/spi-bitbang-txrx.h @@ -45,7 +45,7 @@ static inline u32 bitbang_txrx_be_cpha0(struct spi_device *spi, - unsigned nsecs, unsigned cpol, unsigned flags, + unsigned int nsecs, unsigned int cpol, unsigned int flags, u32 word, u8 bits) { /* if (cpol == 0) this is SPI_MODE_0; else this is SPI_MODE_2 */ @@ -77,7 +77,7 @@ bitbang_txrx_be_cpha0(struct spi_device *spi, static inline u32 bitbang_txrx_be_cpha1(struct spi_device *spi, - unsigned nsecs, unsigned cpol, unsigned flags, + unsigned int nsecs, unsigned int cpol, unsigned int flags, u32 word, u8 bits) { /* if (cpol == 0) this is SPI_MODE_1; else this is SPI_MODE_3 */ @@ -106,3 +106,67 @@ bitbang_txrx_be_cpha1(struct spi_device *spi, } return word; } + +static inline u32 +bitbang_txrx_le_cpha0(struct spi_device *spi, + unsigned int nsecs, unsigned int cpol, unsigned int flags, + u32 word, u8 bits) +{ + /* if (cpol == 0) this is SPI_MODE_0; else this is SPI_MODE_2 */ + + u32 oldbit = !(word & 1); + /* clock starts at inactive polarity */ + for (; likely(bits); bits--) { + + /* setup LSB (to slave) on trailing edge */ + if ((flags & SPI_MASTER_NO_TX) == 0) { + if ((word & 1) != oldbit) { + setmosi(spi, word & 1); + oldbit = word & 1; + } + } + spidelay(nsecs); /* T(setup) */ + + setsck(spi, !cpol); + spidelay(nsecs); + + /* sample LSB (from slave) on leading edge */ + word >>= 1; + if ((flags & SPI_MASTER_NO_RX) == 0) + word |= getmiso(spi) << (bits - 1); + setsck(spi, cpol); + } + return word; +} + +static inline u32 +bitbang_txrx_le_cpha1(struct spi_device *spi, + unsigned int nsecs, unsigned int cpol, unsigned int flags, + u32 word, u8 bits) +{ + /* if (cpol == 0) this is SPI_MODE_1; else this is SPI_MODE_3 */ + + u32 oldbit = !(word & 1); + /* clock starts at inactive polarity */ + for (; likely(bits); bits--) { + + /* setup LSB (to slave) on leading edge */ + setsck(spi, !cpol); + if ((flags & SPI_MASTER_NO_TX) == 0) { + if ((word & 1) != oldbit) { + setmosi(spi, word & 1); + oldbit = word & 1; + } + } + spidelay(nsecs); /* T(setup) */ + + setsck(spi, cpol); + spidelay(nsecs); + + /* sample LSB (from slave) on trailing edge */ + word >>= 1; + if ((flags & SPI_MASTER_NO_RX) == 0) + word |= getmiso(spi) << (bits - 1); + } + return word; +} diff --git a/drivers/spi/spi-gpio.c b/drivers/spi/spi-gpio.c index 7ceb0ba27b75..493723eda844 100644 --- a/drivers/spi/spi-gpio.c +++ b/drivers/spi/spi-gpio.c @@ -135,25 +135,37 @@ static inline int getmiso(const struct spi_device *spi) static u32 spi_gpio_txrx_word_mode0(struct spi_device *spi, unsigned nsecs, u32 word, u8 bits, unsigned flags) { - return bitbang_txrx_be_cpha0(spi, nsecs, 0, flags, word, bits); + if (unlikely(spi->mode & SPI_LSB_FIRST)) + return bitbang_txrx_le_cpha0(spi, nsecs, 0, flags, word, bits); + else + return bitbang_txrx_be_cpha0(spi, nsecs, 0, flags, word, bits); } static u32 spi_gpio_txrx_word_mode1(struct spi_device *spi, unsigned nsecs, u32 word, u8 bits, unsigned flags) { - return bitbang_txrx_be_cpha1(spi, nsecs, 0, flags, word, bits); + if (unlikely(spi->mode & SPI_LSB_FIRST)) + return bitbang_txrx_le_cpha1(spi, nsecs, 0, flags, word, bits); + else + return bitbang_txrx_be_cpha1(spi, nsecs, 0, flags, word, bits); } static u32 spi_gpio_txrx_word_mode2(struct spi_device *spi, unsigned nsecs, u32 word, u8 bits, unsigned flags) { - return bitbang_txrx_be_cpha0(spi, nsecs, 1, flags, word, bits); + if (unlikely(spi->mode & SPI_LSB_FIRST)) + return bitbang_txrx_le_cpha0(spi, nsecs, 1, flags, word, bits); + else + return bitbang_txrx_be_cpha0(spi, nsecs, 1, flags, word, bits); } static u32 spi_gpio_txrx_word_mode3(struct spi_device *spi, unsigned nsecs, u32 word, u8 bits, unsigned flags) { - return bitbang_txrx_be_cpha1(spi, nsecs, 1, flags, word, bits); + if (unlikely(spi->mode & SPI_LSB_FIRST)) + return bitbang_txrx_le_cpha1(spi, nsecs, 1, flags, word, bits); + else + return bitbang_txrx_be_cpha1(spi, nsecs, 1, flags, word, bits); } /* @@ -170,28 +182,40 @@ static u32 spi_gpio_spec_txrx_word_mode0(struct spi_device *spi, unsigned nsecs, u32 word, u8 bits, unsigned flags) { flags = spi->master->flags; - return bitbang_txrx_be_cpha0(spi, nsecs, 0, flags, word, bits); + if (unlikely(spi->mode & SPI_LSB_FIRST)) + return bitbang_txrx_le_cpha0(spi, nsecs, 0, flags, word, bits); + else + return bitbang_txrx_be_cpha0(spi, nsecs, 0, flags, word, bits); } static u32 spi_gpio_spec_txrx_word_mode1(struct spi_device *spi, unsigned nsecs, u32 word, u8 bits, unsigned flags) { flags = spi->master->flags; - return bitbang_txrx_be_cpha1(spi, nsecs, 0, flags, word, bits); + if (unlikely(spi->mode & SPI_LSB_FIRST)) + return bitbang_txrx_le_cpha1(spi, nsecs, 0, flags, word, bits); + else + return bitbang_txrx_be_cpha1(spi, nsecs, 0, flags, word, bits); } static u32 spi_gpio_spec_txrx_word_mode2(struct spi_device *spi, unsigned nsecs, u32 word, u8 bits, unsigned flags) { flags = spi->master->flags; - return bitbang_txrx_be_cpha0(spi, nsecs, 1, flags, word, bits); + if (unlikely(spi->mode & SPI_LSB_FIRST)) + return bitbang_txrx_le_cpha0(spi, nsecs, 1, flags, word, bits); + else + return bitbang_txrx_be_cpha0(spi, nsecs, 1, flags, word, bits); } static u32 spi_gpio_spec_txrx_word_mode3(struct spi_device *spi, unsigned nsecs, u32 word, u8 bits, unsigned flags) { flags = spi->master->flags; - return bitbang_txrx_be_cpha1(spi, nsecs, 1, flags, word, bits); + if (unlikely(spi->mode & SPI_LSB_FIRST)) + return bitbang_txrx_le_cpha1(spi, nsecs, 1, flags, word, bits); + else + return bitbang_txrx_be_cpha1(spi, nsecs, 1, flags, word, bits); } /*----------------------------------------------------------------------*/ @@ -389,7 +413,7 @@ static int spi_gpio_probe(struct platform_device *pdev) master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32); master->mode_bits = SPI_3WIRE | SPI_3WIRE_HIZ | SPI_CPHA | SPI_CPOL | - SPI_CS_HIGH; + SPI_CS_HIGH | SPI_LSB_FIRST; if (!spi_gpio->mosi) { /* HW configuration without MOSI pin *