From patchwork Wed Nov 7 16:22:08 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 10672623 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 412EE13BF for ; Wed, 7 Nov 2018 16:22:15 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2E8F42CAAF for ; Wed, 7 Nov 2018 16:22:15 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2AFBE2CA07; Wed, 7 Nov 2018 16:22:15 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.7 required=2.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 664222CA80 for ; Wed, 7 Nov 2018 16:22:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727668AbeKHBxQ (ORCPT ); Wed, 7 Nov 2018 20:53:16 -0500 Received: from heliosphere.sirena.org.uk ([172.104.155.198]:35174 "EHLO heliosphere.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727576AbeKHBxQ (ORCPT ); Wed, 7 Nov 2018 20:53:16 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sirena.org.uk; s=20170815-heliosphere; h=Date:Message-Id:In-Reply-To: Subject:Cc:To:From:Sender:Reply-To:MIME-Version:Content-Type: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:References: List-Id:List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner: List-Archive; bh=PZeWc9mcHV5fR1HgArcwMCorKmC51gX1mPnOsthA/Vk=; b=dmepVLhJq0yF y375Y9NMhoVX1ai5uKj5C8K5vnDW3rEOFE44bnacfgPmuDpmqziD+O7wY7DH68p4Gay6DhZPWx2Ed Oi0aV2ZrntPgkzFNU5B7R3fPA/Jao1hrqZGfjjPoR2sfY5AXlOh+5zTYDxB7RNVHsfELVTMOxegrA UWHKI=; Received: from cpc102320-sgyl38-2-0-cust46.18-2.cable.virginm.net ([82.37.168.47] helo=debutante.sirena.org.uk) by heliosphere.sirena.org.uk with esmtpa (Exim 4.89) (envelope-from ) id 1gKQan-0006ie-6A; Wed, 07 Nov 2018 16:22:09 +0000 Received: by debutante.sirena.org.uk (Postfix, from userid 1000) id E38511124E14; Wed, 7 Nov 2018 16:22:08 +0000 (GMT) From: Mark Brown To: Linus Walleij Cc: Andrzej Hajda , Lorenzo Bianconi , Mark Brown , Mark Brown , linux-spi@vger.kernel.org, Andrzej Hajda , Lorenzo Bianconi , linux-gpio@vger.kernel.org, linux-spi@vger.kernel.org Subject: Applied "spi: gpio: Support 3WIRE high-impedance turn-around" to the spi tree In-Reply-To: <20181101212504.11723-1-linus.walleij@linaro.org> Message-Id: <20181107162208.E38511124E14@debutante.sirena.org.uk> Date: Wed, 7 Nov 2018 16:22:08 +0000 (GMT) Sender: linux-spi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The patch spi: gpio: Support 3WIRE high-impedance turn-around has been applied to the spi tree at https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted. You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed. If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced. Please add any relevant lists and maintainers to the CCs when replying to this mail. Thanks, Mark From 5132b3d283710d196cd8af99b5585507e8b30709 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Thu, 1 Nov 2018 22:25:04 +0100 Subject: [PATCH] spi: gpio: Support 3WIRE high-impedance turn-around Some devices such as the TPO TPG110 display panel require a "high-impedance turn-around", in effect a clock cycle after switching the line from output to input mode. Support this in the GPIO driver to begin with. Other driver may implement it if they can, it is unclear if this can be achieved with anything else than GPIO bit-banging. Cc: Andrzej Hajda Acked-by: Lorenzo Bianconi Signed-off-by: Linus Walleij Signed-off-by: Mark Brown --- drivers/spi/spi-gpio.c | 24 +++++++++++++++++++++--- include/linux/spi/spi.h | 1 + 2 files changed, 22 insertions(+), 3 deletions(-) diff --git a/drivers/spi/spi-gpio.c b/drivers/spi/spi-gpio.c index 45973ee3ae11..a4aee26028cd 100644 --- a/drivers/spi/spi-gpio.c +++ b/drivers/spi/spi-gpio.c @@ -256,11 +256,29 @@ static int spi_gpio_setup(struct spi_device *spi) static int spi_gpio_set_direction(struct spi_device *spi, bool output) { struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi); + int ret; if (output) return gpiod_direction_output(spi_gpio->mosi, 1); - else - return gpiod_direction_input(spi_gpio->mosi); + + ret = gpiod_direction_input(spi_gpio->mosi); + if (ret) + return ret; + /* + * Send a turnaround high impedance cycle when switching + * from output to input. Theoretically there should be + * a clock delay here, but as has been noted above, the + * nsec delay function for bit-banged GPIO is simply + * {} because bit-banging just doesn't get fast enough + * anyway. + */ + if (spi->mode & SPI_3WIRE_HIZ) { + gpiod_set_value_cansleep(spi_gpio->sck, + !(spi->mode & SPI_CPOL)); + gpiod_set_value_cansleep(spi_gpio->sck, + !!(spi->mode & SPI_CPOL)); + } + return 0; } static void spi_gpio_cleanup(struct spi_device *spi) @@ -410,7 +428,7 @@ static int spi_gpio_probe(struct platform_device *pdev) return status; master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32); - master->mode_bits = SPI_3WIRE | SPI_CPHA | SPI_CPOL; + master->mode_bits = SPI_3WIRE | SPI_3WIRE_HIZ | SPI_CPHA | SPI_CPOL; master->flags = master_flags; master->bus_num = pdev->id; /* The master needs to think there is a chipselect even if not connected */ diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index 6be77fa5ab90..3ced58eebe1b 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -155,6 +155,7 @@ struct spi_device { #define SPI_RX_DUAL 0x400 /* receive with 2 wires */ #define SPI_RX_QUAD 0x800 /* receive with 4 wires */ #define SPI_CS_WORD 0x1000 /* toggle cs after each word */ +#define SPI_3WIRE_HIZ 0x2000 /* high impedance turnaround */ int irq; void *controller_state; void *controller_data;