From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jean-Christophe PLAGNIOL-VILLARD Subject: Re: [PATCH 2/3] of_spi: add generic binding support to specify ncs gpio Date: Mon, 20 Feb 2012 10:56:39 +0100 Message-ID: <20120220095639.GA11307@game.jcrosoft.org> References: <1328804077-6121-1-git-send-email-plagnioj@jcrosoft.com> <1328804077-6121-2-git-send-email-plagnioj@jcrosoft.com> <20120214042419.GG3378@game.jcrosoft.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org To: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Grant Likely Return-path: Content-Disposition: inline In-Reply-To: <20120214042419.GG3378-RQcB7r2h9QmfDR2tN2SG5Ni2O/JbrIOy@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Sender: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org List-Id: linux-spi.vger.kernel.org Hi Grant, can I have a feedback the Atmel SPI depend on it Best Regards, J. On 05:24 Tue 14 Feb , Jean-Christophe PLAGNIOL-VILLARD wrote: > Hi Grant, > > ping > > Best Regards, > J. > On 17:14 Thu 09 Feb , Jean-Christophe PLAGNIOL-VILLARD wrote: > > This will allow to use gpio for chip select with no modification in the > > driver binding > > > > When use the ncs-gpios, the gpio number will be passed via the controller_data > > and the number of chip select will automatically increased. > > > > Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD > > Cc: devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org > > Cc: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org > > --- > > Documentation/devicetree/bindings/spi/spi-bus.txt | 6 +++ > > drivers/of/of_spi.c | 27 ++++++++--- > > drivers/spi/spi.c | 51 +++++++++++++++++++- > > include/linux/spi/spi.h | 5 ++ > > 4 files changed, 78 insertions(+), 11 deletions(-) > > > > diff --git a/Documentation/devicetree/bindings/spi/spi-bus.txt b/Documentation/devicetree/bindings/spi/spi-bus.txt > > index e782add..5a24729 100644 > > --- a/Documentation/devicetree/bindings/spi/spi-bus.txt > > +++ b/Documentation/devicetree/bindings/spi/spi-bus.txt > > @@ -12,6 +12,7 @@ The SPI master node requires the following properties: > > - #size-cells - should be zero. > > - compatible - name of SPI bus controller following generic names > > recommended practice. > > +- ncs-gpios - (optional) gpios chip select. > > No other properties are required in the SPI bus node. It is assumed > > that a driver for an SPI bus device will understand that it is an SPI bus. > > However, the binding does not attempt to define the specific method for > > @@ -21,6 +22,8 @@ assumption that board specific platform code will be used to manage > > chip selects. Individual drivers can define additional properties to > > support describing the chip select layout. > > > > +If ncs-gpios is used the number of chip select will automatically increased. > > + > > SPI slave nodes must be children of the SPI master node and can > > contain the following properties. > > - reg - (required) chip select address of device. > > @@ -34,6 +37,9 @@ contain the following properties. > > - spi-cs-high - (optional) Empty property indicating device requires > > chip select active high > > > > +If a gpio chipselect is used for the SPI slave the gpio number will be passed > > +via the controller_data > > + > > SPI example for an MPC5200 SPI bus: > > spi@f00 { > > #address-cells = <1>; > > diff --git a/drivers/of/of_spi.c b/drivers/of/of_spi.c > > index 6dbc074..0d41407 100644 > > --- a/drivers/of/of_spi.c > > +++ b/drivers/of/of_spi.c > > @@ -12,6 +12,7 @@ > > #include > > #include > > #include > > +#include > > > > /** > > * of_register_spi_devices - Register child devices onto the SPI bus > > @@ -27,6 +28,7 @@ void of_register_spi_devices(struct spi_master *master) > > const __be32 *prop; > > int rc; > > int len; > > + int ncs_pin; > > > > if (!master->dev.of_node) > > return; > > @@ -50,15 +52,24 @@ void of_register_spi_devices(struct spi_master *master) > > continue; > > } > > > > - /* Device address */ > > - prop = of_get_property(nc, "reg", &len); > > - if (!prop || len < sizeof(*prop)) { > > - dev_err(&master->dev, "%s has no 'reg' property\n", > > - nc->full_name); > > - spi_dev_put(spi); > > - continue; > > + /* ncs gpio */ > > + ncs_pin = of_get_named_gpio(nc, "ncs-gpio", 0); > > + > > + if (gpio_is_valid(ncs_pin)) { > > + spi->controller_data = (void *)ncs_pin; > > + spi->chip_select = master->num_chipselect; > > + master->num_chipselect++; > > + } else { > > + /* Device address */ > > + prop = of_get_property(nc, "reg", &len); > > + if (!prop || len < sizeof(*prop)) { > > + dev_err(&master->dev, "%s has no 'reg' property\n", > > + nc->full_name); > > + spi_dev_put(spi); > > + continue; > > + } > > + spi->chip_select = be32_to_cpup(prop); > > } > > - spi->chip_select = be32_to_cpup(prop); > > > > /* Mode (clock phase/polarity/etc.) */ > > if (of_find_property(nc, "spi-cpha", NULL)) > > diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c > > index e2f4ca0..1f5ffa6 100644 > > --- a/drivers/spi/spi.c > > +++ b/drivers/spi/spi.c > > @@ -28,6 +28,7 @@ > > #include > > #include > > #include > > +#include > > #include > > #include > > > > @@ -339,15 +340,16 @@ EXPORT_SYMBOL_GPL(spi_alloc_device); > > int spi_add_device(struct spi_device *spi) > > { > > static DEFINE_MUTEX(spi_add_lock); > > - struct device *dev = spi->master->dev.parent; > > + struct spi_master *master = spi->master; > > + struct device *dev = master->dev.parent; > > struct device *d; > > int status; > > > > /* Chipselects are numbered 0..max; validate. */ > > - if (spi->chip_select >= spi->master->num_chipselect) { > > + if (spi->chip_select >= master->num_chipselect) { > > dev_err(dev, "cs%d >= max %d\n", > > spi->chip_select, > > - spi->master->num_chipselect); > > + master->num_chipselect); > > return -EINVAL; > > } > > > > @@ -371,6 +373,13 @@ int spi_add_device(struct spi_device *spi) > > goto done; > > } > > > > + if (master->num_gpio_chipselect && > > + spi->chip_select >= master->first_gpio_chipselect) { > > + int num = spi->chip_select = master->first_gpio_chipselect; > > + > > + spi->controller_data = (void*)master->chipselect_gpios[num]; > > + } > > + > > /* Drivers may modify this initial i/o setup, but will > > * normally rely on the device being setup. Devices > > * using SPI_CS_HIGH can't coexist well otherwise... > > @@ -562,6 +571,38 @@ struct spi_master *spi_alloc_master(struct device *dev, unsigned size) > > } > > EXPORT_SYMBOL_GPL(spi_alloc_master); > > > > +static int of_spi_register_master(struct spi_master *master) > > +{ > > + int nb, i; > > + int *cs; > > + struct device_node *np = master->dev.of_node; > > + > > + if (!np) > > + return 0; > > + > > + nb = of_gpio_named_count(np, "ncs-gpios"); > > + > > + if (nb < 1) > > + return 0; > > + > > + master->chipselect_gpios = kzalloc(sizeof(int) * nb, GFP_KERNEL); > > + > > + if (!master->chipselect_gpios) > > + return -ENOMEM; > > + > > + master->first_gpio_chipselect = master->num_chipselect; > > + master->num_chipselect += nb; > > + master->num_gpio_chipselect = nb; > > + > > + for (i = 0; i < nb; i++) { > > + cs = &master->chipselect_gpios[i]; > > + > > + *cs = of_get_named_gpio(np, "ncs-gpios", i); > > + } > > + > > + return 0; > > +} > > + > > /** > > * spi_register_master - register SPI master controller > > * @master: initialized master, originally from spi_alloc_master() > > @@ -593,6 +634,10 @@ int spi_register_master(struct spi_master *master) > > if (!dev) > > return -ENODEV; > > > > + status = of_spi_register_master(master); > > + if (status) > > + return status; > > + > > /* even if it's just one always-selected device, there must > > * be at least one chipselect > > */ > > diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h > > index 176fce9..d21c267 100644 > > --- a/include/linux/spi/spi.h > > +++ b/include/linux/spi/spi.h > > @@ -318,6 +318,11 @@ struct spi_master { > > > > /* called on release() to free memory provided by spi_master */ > > void (*cleanup)(struct spi_device *spi); > > + > > + /* gpio chip select */ > > + int *chipselect_gpios; > > + int first_gpio_chipselect; > > + int num_gpio_chipselect; > > }; > > > > static inline void *spi_master_get_devdata(struct spi_master *master) > > -- > > 1.7.7 > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel