From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751538Ab3BKAXZ (ORCPT ); Sun, 10 Feb 2013 19:23:25 -0500 Received: from mail-wi0-f180.google.com ([209.85.212.180]:47676 "EHLO mail-wi0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751061Ab3BKAXY (ORCPT ); Sun, 10 Feb 2013 19:23:24 -0500 From: Grant Likely Subject: Re: [PATCH v2 6/6] of_spi: Initialize cs_gpios and cs_gpio with -EEXIST To: Andreas Larsson Cc: Rob Herring , Linus Walleij , devicetree-discuss@lists.ozlabs.org, spi-devel-general@lists.sourceforge.net, linux-kernel@vger.kernel.org, software@gaisler.com In-Reply-To: <1359471223-4794-7-git-send-email-andreas@gaisler.com> References: <1359471223-4794-1-git-send-email-andreas@gaisler.com> <1359471223-4794-7-git-send-email-andreas@gaisler.com> Date: Mon, 11 Feb 2013 00:23:20 +0000 Message-Id: <20130211002320.824593E0C13@localhost> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 29 Jan 2013 15:53:43 +0100, Andreas Larsson wrote: > Holes in the cs-gpios DT phandle list is supposed to mark that native > chipselects is to be used. The value returned from of_get_named_gpio_flags in > this case is -EEXIST. By initializing cs_gpios and cs_gpio with -EEXIST, this > and only this errno will indicate to a spi controller driver that a native > chipselect is to be used. > > Signed-off-by: Andreas Larsson I've left this one off for now. Take a look at the patch I posted and let me know if you think this one should still be applied. g. > --- > drivers/spi/spi.c | 4 ++-- > include/linux/spi/spi.h | 7 +++++-- > 2 files changed, 7 insertions(+), 4 deletions(-) > > diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c > index 6f1b717..7494bad 100644 > --- a/drivers/spi/spi.c > +++ b/drivers/spi/spi.c > @@ -334,7 +334,7 @@ struct spi_device *spi_alloc_device(struct spi_master *master) > spi->dev.parent = &master->dev; > spi->dev.bus = &spi_bus_type; > spi->dev.release = spidev_release; > - spi->cs_gpio = -EINVAL; > + spi->cs_gpio = -EEXIST; > device_initialize(&spi->dev); > return spi; > } > @@ -1097,7 +1097,7 @@ static int of_spi_register_master(struct spi_master *master) > } > > for (i = 0; i < master->num_chipselect; i++) > - cs[i] = -EINVAL; > + cs[i] = -EEXIST; > > for (i = 0; i < nb; i++) > cs[i] = of_get_named_gpio_flags(np, "cs-gpios", i, &flags[i]); > diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h > index 96b1055..0701882 100644 > --- a/include/linux/spi/spi.h > +++ b/include/linux/spi/spi.h > @@ -58,7 +58,8 @@ extern struct bus_type spi_bus_type; > * @modalias: Name of the driver to use with this device, or an alias > * for that name. This appears in the sysfs "modalias" attribute > * for driver coldplugging, and in uevents used for hotplugging > - * @cs_gpio: Negative or gpio for chip select. > + * @cs_gpio: Negative or gpio for chip select. Set to -EEXIST when chipselect > + * should be handled natively by the controller driver > * @cs_gpio_flags: of_gpio_flags corresponding to cs_gpio > * > * A @spi_device is used to interchange data between an SPI slave > @@ -262,7 +263,9 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv) > * @unprepare_transfer_hardware: there are currently no more messages on the > * queue so the subsystem notifies the driver that it may relax the > * hardware by issuing this call > - * @cs_gpios: possible array of negative values or gpios for chip selects > + * @cs_gpios: possible array of negative values or gpios for chip selects. A > + * chipselect that should be handled natively by the controller driver is > + * set to -EEXIST. > * @cs_gpio_flags: possible array of of_gpio_flags corresponding to cs_gpios > * > * Each SPI master controller can communicate with one or more @spi_device > -- > 1.7.0.4 > -- Grant Likely, B.Sc, P.Eng. Secret Lab Technologies, Ltd.