From patchwork Wed Nov 25 20:41:59 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Torsten Fleischer X-Patchwork-Id: 39462 X-Patchwork-Delegate: galak@kernel.crashing.org Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from bilbo.ozlabs.org (localhost [127.0.0.1]) by ozlabs.org (Postfix) with ESMTP id E2931100A3B for ; Thu, 26 Nov 2009 08:21:15 +1100 (EST) Received: from mailout01.t-online.de (mailout01.t-online.de [194.25.134.80]) by ozlabs.org (Postfix) with ESMTP id 8E7D7B6F1C for ; Thu, 26 Nov 2009 08:21:06 +1100 (EST) Received: from fwd05.aul.t-online.de by mailout01.t-online.de with smtp id 1NDOgi-0004W3-00; Wed, 25 Nov 2009 21:42:08 +0100 Received: from linux-z6s0.localnet (JbSgHcZ-rhtIDXSFcB2L1dPJKCIhFUrKiLXrt+cRWTIgqcHMsYorr0Re1aN-kUIZ-+@[87.163.49.253]) by fwd05.t-online.de with esmtp id 1NDOga-16KNSy0; Wed, 25 Nov 2009 21:42:00 +0100 From: Torsten Fleischer Organization: privat To: Grant Likely Subject: Re: spi_mpc8xxx.c: chip select polarity problem Date: Wed, 25 Nov 2009 21:41:59 +0100 User-Agent: KMail/1.12.2 (Linux/2.6.31.5-0.1-default; KDE/4.3.1; i686; ; ) References: <200911161742.46663.to-fleischer@t-online.de> <200911211708.47253.to-fleischer@t-online.de> In-Reply-To: MIME-Version: 1.0 Message-Id: <200911252141.59549.to-fleischer@t-online.de> X-ID: JbSgHcZ-rhtIDXSFcB2L1dPJKCIhFUrKiLXrt+cRWTIgqcHMsYorr0Re1aN-kUIZ-+ X-TOI-MSGID: 6bff2c57-d5be-48d6-97de-9d2ed233ba43 Cc: linuxppc-dev@lists.ozlabs.org X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org On Wen, Nov 25, 2009 at 01:33:57 Grant Likely wrote: > Thanks. However, there needs to be a proper description of what this > patch does to go in the commit header. Can you please write one? > > Thanks, > g. > [...] The initialization of the chip selects is removed from the probe() function of the spi_mpc8xxx driver, because the driver doesn't know the polarity of the chip selects of the SPI devices at the time of its initialization. For this reason the initialization of the several chip selects is postponed to the point of time when the very first SPI transfer to the associated device occurs. Signed-off-by: Torsten Fleischer diff -u -r -N linux-2.6.31.6_orig//drivers/spi/spi_mpc8xxx.c linux-2.6.31.6/drivers/spi/spi_mpc8xxx.c --- linux-2.6.31.6_orig//drivers/spi/spi_mpc8xxx.c 2009-11-10 01:32:31.000000000 +0100 +++ linux-2.6.31.6/drivers/spi/spi_mpc8xxx.c 2009-11-19 08:15:33.000000000 +0100 @@ -114,6 +114,7 @@ u32 rx_shift; /* RX data reg shift when in qe mode */ u32 tx_shift; /* TX data reg shift when in qe mode */ u32 hw_mode; /* Holds HW mode register settings */ + int initialized; }; static inline void mpc8xxx_spi_write_reg(__be32 __iomem *reg, u32 val) @@ -503,15 +504,52 @@ return ret; } + + +struct mpc8xxx_spi_probe_info { + struct fsl_spi_platform_data pdata; + int *gpios; + bool *alow_flags; +}; + +static struct mpc8xxx_spi_probe_info * +to_of_pinfo(struct fsl_spi_platform_data *pdata) +{ + return container_of(pdata, struct mpc8xxx_spi_probe_info, pdata); +} + +static int mpc8xxx_spi_cs_init(struct spi_device *spi) +{ + struct device *dev = spi->dev.parent; + struct mpc8xxx_spi_probe_info *pinfo = to_of_pinfo(dev->platform_data); + u16 cs = spi->chip_select; + int gpio = pinfo->gpios[cs]; + bool on = pinfo->alow_flags[cs] ^ !(spi->mode & SPI_CS_HIGH); + + return gpio_direction_output(gpio, on); +} + static int mpc8xxx_spi_transfer(struct spi_device *spi, struct spi_message *m) { struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master); + struct spi_mpc8xxx_cs *cs = spi->controller_state; unsigned long flags; m->actual_length = 0; m->status = -EINPROGRESS; + if (cs && !cs->initialized) { + int ret; + + ret = mpc8xxx_spi_cs_init(spi); + if (ret) { + dev_dbg(&spi->dev, "cs_init failed: %d\n", ret); + return ret; + } + cs->initialized = 1; + } + spin_lock_irqsave(&mpc8xxx_spi->lock, flags); list_add_tail(&m->queue, &mpc8xxx_spi->queue); queue_work(mpc8xxx_spi->workqueue, &mpc8xxx_spi->work); @@ -648,18 +686,6 @@ return 0; } -struct mpc8xxx_spi_probe_info { - struct fsl_spi_platform_data pdata; - int *gpios; - bool *alow_flags; -}; - -static struct mpc8xxx_spi_probe_info * -to_of_pinfo(struct fsl_spi_platform_data *pdata) -{ - return container_of(pdata, struct mpc8xxx_spi_probe_info, pdata); -} - static void mpc8xxx_spi_cs_control(struct spi_device *spi, bool on) { struct device *dev = spi->dev.parent; @@ -720,14 +746,6 @@ pinfo->gpios[i] = gpio; pinfo->alow_flags[i] = flags & OF_GPIO_ACTIVE_LOW; - - ret = gpio_direction_output(pinfo->gpios[i], - pinfo->alow_flags[i]); - if (ret) { - dev_err(dev, "can't set output direction for gpio " - "#%d: %d\n", i, ret); - goto err_loop; - } } pdata->max_chipselect = ngpios;