Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964926Ab3DOIlD (ORCPT ); Mon, 15 Apr 2013 04:41:03 -0400 Received: from mail-pd0-f180.google.com ([209.85.192.180]:52414 "EHLO mail-pd0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964810Ab3DOIk7 (ORCPT ); Mon, 15 Apr 2013 04:40:59 -0400 From: Girish K S To: spi-devel-general@lists.sourceforge.net, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: grant.likely@secretlab.ca, t.figa@samsung.com, broonie@opensource.wolfsonmicro.com, Girish K S Subject: [PATCH V4 4/5] spi: s3c64xx: Added provision for dedicated cs pin Date: Mon, 15 Apr 2013 14:10:29 +0530 Message-Id: <1366015230-18243-3-git-send-email-ks.giri@samsung.com> X-Mailer: git-send-email 1.7.5.4 In-Reply-To: <1366015230-18243-1-git-send-email-ks.giri@samsung.com> References: <1366015230-18243-1-git-send-email-ks.giri@samsung.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4438 Lines: 136 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 --- changes in v4: moved the struct member cs_gpio from platform data to driver private data. changes in v3: detelted the quirk for GPIO and handled it in the dts file changes in v2: separated the gpio ios and cs gpio as separate patches drivers/spi/spi-s3c64xx.c | 32 ++++++++++++++++++++++++-------- 1 files changed, 24 insertions(+), 8 deletions(-) diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c index 79de18f..7fdc940 100644 --- a/drivers/spi/spi-s3c64xx.c +++ b/drivers/spi/spi-s3c64xx.c @@ -202,6 +202,7 @@ struct s3c64xx_spi_driver_data { struct s3c64xx_spi_port_config *port_conf; unsigned int port_id; unsigned long gpios[4]; + bool cs_gpio; }; static struct s3c2410_dma_client s3c64xx_spi_dma_client = { @@ -414,14 +415,16 @@ 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 (sdd->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 (sdd->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 +553,8 @@ 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 (sdd->cs_gpio) + gpio_set_value(cs->line, spi->mode & SPI_CS_HIGH ? 0 : 1); /* Quiese the signals */ writel(S3C64XX_SPI_SLAVE_SIG_INACT, sdd->regs + S3C64XX_SPI_SLAVE_SEL); @@ -888,7 +892,10 @@ static struct s3c64xx_spi_csinfo *s3c64xx_get_slave_ctrldata( return ERR_PTR(-ENOMEM); } - cs->line = of_get_named_gpio(data_np, "cs-gpio", 0); + /* The CS line is asserted/deasserted by the gpio pin */ + if (sdd->cs_gpio) + 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); @@ -928,7 +935,8 @@ 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 (sdd->cs_gpio) { err = gpio_request_one(cs->line, GPIOF_OUT_INIT_HIGH, dev_name(&spi->dev)); if (err) { @@ -937,9 +945,11 @@ 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); @@ -1026,8 +1036,10 @@ err_gpio_req: static void s3c64xx_spi_cleanup(struct spi_device *spi) { struct s3c64xx_spi_csinfo *cs = spi_get_ctldata(spi); + struct s3c64xx_spi_driver_data *sdd; - if (cs) { + sdd = spi_master_get_devdata(spi->master); + if (cs && sdd->cs_gpio) { gpio_free(cs->line); if (spi->dev.of_node) kfree(cs); @@ -1256,7 +1268,11 @@ static int s3c64xx_spi_probe(struct platform_device *pdev) sdd->cntrlr_info = sci; sdd->pdev = pdev; sdd->sfr_start = mem_res->start; + sdd->cs_gpio = false; if (pdev->dev.of_node) { + if (of_find_property(pdev->dev.of_node, "cs-gpio", NULL)) + sdd->cs_gpio = true; + ret = of_alias_get_id(pdev->dev.of_node, "spi"); if (ret < 0) { dev_err(&pdev->dev, "failed to get alias id, errno %d\n", -- 1.7.5.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/