Messages in this thread Patch in this message | | | From | Andreas Larsson <> | Subject | [PATCH 5/6] of_spi: Add fetching of of_gpio flags to of_spi_register_master | Date | Thu, 27 Dec 2012 13:10:46 +0100 |
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When using a gpio chip select with a OF_GPIO_ACTIVE_LOW flag, this needs to be known to the controller driver.
Signed-off-by: Andreas Larsson <andreas@gaisler.com> --- Documentation/devicetree/bindings/spi/spi-bus.txt | 3 +- drivers/spi/spi.c | 24 ++++++++++++++++++-- include/linux/spi/spi.h | 5 ++++ 3 files changed, 28 insertions(+), 4 deletions(-)
diff --git a/Documentation/devicetree/bindings/spi/spi-bus.txt b/Documentation/devicetree/bindings/spi/spi-bus.txt index 296015e..a4950a6 100644 --- a/Documentation/devicetree/bindings/spi/spi-bus.txt +++ b/Documentation/devicetree/bindings/spi/spi-bus.txt @@ -57,7 +57,8 @@ contain the following properties. 3-wire mode. If a gpio chipselect is used for the SPI slave the gpio number will be passed -via the cs_gpio +via the cs_gpio and the corresponding of_gpio_flags will be passed via +cs_gpio_flags. SPI example for an MPC5200 SPI bus: spi@f00 { diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index a4baa0a..6f1b717 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -385,8 +385,10 @@ int spi_add_device(struct spi_device *spi) goto done; } - if (master->cs_gpios) + if (master->cs_gpios) { spi->cs_gpio = master->cs_gpios[spi->chip_select]; + spi->cs_gpio_flags = master->cs_gpio_flags[spi->chip_select]; + } /* Drivers may modify this initial i/o setup, but will * normally rely on the device being setup. Devices @@ -1060,7 +1062,8 @@ EXPORT_SYMBOL_GPL(spi_alloc_master); static int of_spi_register_master(struct spi_master *master) { int nb; - int i, *cs; + int ret, i, *cs; + enum of_gpio_flags *flags; struct device_node *np = master->dev.of_node; if (!np) @@ -1083,13 +1086,28 @@ static int of_spi_register_master(struct spi_master *master) if (!master->cs_gpios) return -ENOMEM; + flags = devm_kzalloc(&master->dev, + sizeof(*flags) * master->num_chipselect, + GFP_KERNEL); + master->cs_gpio_flags = flags; + + if (!master->cs_gpio_flags) { + ret = -ENOMEM; + goto err_alloc_flags; + } + for (i = 0; i < master->num_chipselect; i++) cs[i] = -EINVAL; for (i = 0; i < nb; i++) - cs[i] = of_get_named_gpio(np, "cs-gpios", i); + cs[i] = of_get_named_gpio_flags(np, "cs-gpios", i, &flags[i]); return 0; + +err_alloc_flags: + devm_kfree(&master->dev, master->cs_gpios); + master->cs_gpios = NULL; + return ret; } #else static int of_spi_register_master(struct spi_master *master) diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index 88a669c..96b1055 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -23,6 +23,7 @@ #include <linux/mod_devicetable.h> #include <linux/slab.h> #include <linux/kthread.h> +#include <linux/of_gpio.h> /* * INTERFACES between SPI master-side drivers and SPI infrastructure. @@ -58,6 +59,7 @@ extern struct bus_type spi_bus_type; * 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_flags: of_gpio_flags corresponding to cs_gpio * * A @spi_device is used to interchange data between an SPI slave * (usually a discrete chip) and CPU memory. @@ -92,6 +94,7 @@ struct spi_device { void *controller_data; char modalias[SPI_NAME_SIZE]; int cs_gpio; /* chip select gpio */ + enum of_gpio_flags cs_gpio_flags; /* chip select of_gpio_flags */ /* * likely need more hooks for more protocol options affecting how @@ -260,6 +263,7 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv) * 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_gpio_flags: possible array of of_gpio_flags corresponding to cs_gpios * * Each SPI master controller can communicate with one or more @spi_device * children. These make a small bus, sharing MOSI, MISO and SCK signals @@ -367,6 +371,7 @@ struct spi_master { int (*unprepare_transfer_hardware)(struct spi_master *master); /* gpio chip select */ int *cs_gpios; + enum of_gpio_flags *cs_gpio_flags; }; static inline void *spi_master_get_devdata(struct spi_master *master) -- 1.7.0.4
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