From patchwork Wed Mar 13 06:43:33 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: girishks2000@gmail.com X-Patchwork-Id: 2261901 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork2.kernel.org (Postfix) with ESMTP id 6846ADF215 for ; Wed, 13 Mar 2013 06:47:58 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UFfR3-0006Lr-NE; Wed, 13 Mar 2013 06:45:13 +0000 Received: from mail-ie0-x22c.google.com ([2607:f8b0:4001:c03::22c]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1UFfQ1-00061i-FL for linux-arm-kernel@lists.infradead.org; Wed, 13 Mar 2013 06:44:10 +0000 Received: by mail-ie0-f172.google.com with SMTP id c10so978457ieb.17 for ; Tue, 12 Mar 2013 23:44:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=x-received:from:to:cc:subject:date:message-id:x-mailer:in-reply-to :references; bh=DS6lh4v+seYEK+9Hahe0C/l5PdGPj9yt8wMgXyRkwrk=; b=QL7W0Je1nLKgeFCc5fqHrEK/UH1RBYqPVq0V35IuF9Qp13Fzzck19/dDIrqO5KUmI3 Kx6pUx3KUcb81zUnXa/AT1kzN0TKtdFDPibsKl/eLBH3dBUBO6KU9+JBBMY/Lnd+W0L4 +Nysfv/wp6dg8aqbIeej4Xito5U75tdqohcDwCkG6Z2MpxrIoQNcRPOq/S/pmfdxloU5 vqN5gCefeGHzKDsoml5mmwD75T5VwmR+FCr56kn6ecmZoQJYg1jNMzccTT83ZNO2a0Ho HA25lYibP9bY3eV6mLx4dVoJhLD7DsEtn745vmHhKYSkxKYsQ8JxITxOsSu1bPzwAzu0 gdqQ== X-Received: by 10.50.17.234 with SMTP id r10mr14316696igd.102.1363157048521; Tue, 12 Mar 2013 23:44:08 -0700 (PDT) Received: from localhost.localdomain ([115.113.119.130]) by mx.google.com with ESMTPS id hi4sm1406711igc.6.2013.03.12.23.44.03 (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 12 Mar 2013 23:44:08 -0700 (PDT) From: Girish K S To: spi-devel-general@lists.sourceforge.net, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH V3 4/5] spi: s3c64xx: Added provision for dedicated cs pin Date: Wed, 13 Mar 2013 12:13:33 +0530 Message-Id: <1363157014-9615-5-git-send-email-ks.giri@samsung.com> X-Mailer: git-send-email 1.7.5.4 In-Reply-To: <1363157014-9615-1-git-send-email-ks.giri@samsung.com> References: <1363157014-9615-1-git-send-email-ks.giri@samsung.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130313_024410_084707_32DC36CE X-CRM114-Status: GOOD ( 18.44 ) X-Spam-Score: -1.8 (-) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-1.8 points) pts rule name description ---- ---------------------- -------------------------------------------------- 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (girishks2000[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record 0.2 FREEMAIL_ENVFROM_END_DIGIT Envelope-from freemail username ends in digit (girishks2000[at]gmail.com) -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature Cc: grant.likely@secretlab.ca, t.figa@samsung.com, broonie@opensource.wolfsonmicro.com, Girish K S X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org From: Girish K S The existing driver supports gpio based /cs signal. For controller's that have one device per controller, the slave device's /cs signal might be internally controlled by the chip select bit of slave select register. They are not externally asserted/deasserted using gpio pin. This patch adds support for controllers with dedicated /cs pin. if "cs-gpio" property doesnt exist in a spi dts node, the controller would treat the /cs pin as dedicated. Signed-off-by: Girish K S --- drivers/spi/spi-s3c64xx.c | 27 +++++++++++++++++++-------- include/linux/platform_data/spi-s3c64xx.h | 3 +++ 2 files changed, 22 insertions(+), 8 deletions(-) diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c index 94716d1..ac557f8 100644 --- a/drivers/spi/spi-s3c64xx.c +++ b/drivers/spi/spi-s3c64xx.c @@ -414,14 +414,16 @@ static inline void enable_cs(struct s3c64xx_spi_driver_data *sdd, if (sdd->tgl_spi != spi) { /* if last mssg on diff device */ /* Deselect the last toggled device */ cs = sdd->tgl_spi->controller_data; - gpio_set_value(cs->line, - spi->mode & SPI_CS_HIGH ? 0 : 1); + if (cs->cs_gpio) + gpio_set_value(cs->line, + spi->mode & SPI_CS_HIGH ? 0 : 1); } sdd->tgl_spi = NULL; } cs = spi->controller_data; - gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 1 : 0); + if (cs->cs_gpio) + gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 1 : 0); /* Start the signals */ writel(0, sdd->regs + S3C64XX_SPI_SLAVE_SEL); @@ -550,7 +552,8 @@ static inline void disable_cs(struct s3c64xx_spi_driver_data *sdd, if (sdd->tgl_spi == spi) sdd->tgl_spi = NULL; - gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 0 : 1); + if (cs->cs_gpio) + gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 0 : 1); /* Quiese the signals */ writel(S3C64XX_SPI_SLAVE_SIG_INACT, @@ -889,7 +892,12 @@ static struct s3c64xx_spi_csinfo *s3c64xx_get_slave_ctrldata( return ERR_PTR(-ENOMEM); } - cs->line = of_get_named_gpio(data_np, "cs-gpio", 0); + if (of_find_property(data_np, "cs-gpio", NULL)) { + /* The CS line is asserted/deasserted by the gpio pin */ + cs->cs_gpio = true; + cs->line = of_get_named_gpio(data_np, "cs-gpio", 0); + } + if (!gpio_is_valid(cs->line)) { dev_err(&spi->dev, "chip select gpio is not specified or invalid\n"); kfree(cs); @@ -929,7 +937,8 @@ static int s3c64xx_spi_setup(struct spi_device *spi) return -ENODEV; } - if (!spi_get_ctldata(spi)) { + /* Request gpio only if cs line is asserted by gpio pins */ + if (cs->cs_gpio) { err = gpio_request_one(cs->line, GPIOF_OUT_INIT_HIGH, dev_name(&spi->dev)); if (err) { @@ -938,9 +947,11 @@ static int s3c64xx_spi_setup(struct spi_device *spi) cs->line, err); goto err_gpio_req; } - spi_set_ctldata(spi, cs); } + if (!spi_get_ctldata(spi)) + spi_set_ctldata(spi, cs); + sci = sdd->cntrlr_info; spin_lock_irqsave(&sdd->lock, flags); @@ -1028,7 +1039,7 @@ static void s3c64xx_spi_cleanup(struct spi_device *spi) { struct s3c64xx_spi_csinfo *cs = spi_get_ctldata(spi); - if (cs) { + if (cs && cs->cs_gpio) { gpio_free(cs->line); if (spi->dev.of_node) kfree(cs); diff --git a/include/linux/platform_data/spi-s3c64xx.h b/include/linux/platform_data/spi-s3c64xx.h index ceba18d..0343d8d 100644 --- a/include/linux/platform_data/spi-s3c64xx.h +++ b/include/linux/platform_data/spi-s3c64xx.h @@ -17,6 +17,8 @@ struct platform_device; * struct s3c64xx_spi_csinfo - ChipSelect description * @fb_delay: Slave specific feedback delay. * Refer to FB_CLK_SEL register definition in SPI chapter. + * @cs_gpio: CS line status, 'true' if CS line is asserted by gpio. + * 'false' if asserted by internal dedicated pin. * @line: Custom 'identity' of the CS line. * * This is per SPI-Slave Chipselect information. @@ -25,6 +27,7 @@ struct platform_device; */ struct s3c64xx_spi_csinfo { u8 fb_delay; + bool cs_gpio; unsigned line; };