Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932879Ab3CMGoT (ORCPT ); Wed, 13 Mar 2013 02:44:19 -0400 Received: from mail-ie0-f179.google.com ([209.85.223.179]:46523 "EHLO mail-ie0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932328Ab3CMGoI (ORCPT ); Wed, 13 Mar 2013 02:44:08 -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 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> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4295 Lines: 127 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; }; -- 1.8.0 -- 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/