From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcus Weseloh Subject: [PATCH v6 1/3] spi: dts: Add new device property to specifcy a wait time between word transmissions Date: Sat, 26 Dec 2015 16:53:04 +0100 Message-ID: <1451145186-14235-2-git-send-email-mweseloh42@gmail.com> References: <1451145186-14235-1-git-send-email-mweseloh42@gmail.com> Reply-To: mweseloh42-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: Chen-Yu Tsai , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Ian Campbell , Kumar Gala , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Marcus Weseloh , Mark Brown , Mark Rutland , Maxime Ripard , Pawel Moll , Rob Herring To: linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org Return-path: In-Reply-To: <1451145186-14235-1-git-send-email-mweseloh42-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> List-Post: , List-Help: , List-Archive: , List-Unsubscribe: , List-Id: linux-spi.vger.kernel.org Adds a new property "spi-word-wait-ns" to the spi-bus binding that allows SPI slave devices to set a wait time between the transmission of words. Signed-off-by: Marcus Weseloh Reviewed-by: Maxime Ripard Acked-by: Rob Herring --- Documentation/devicetree/bindings/spi/spi-bus.txt | 2 ++ drivers/spi/spi.c | 2 ++ include/linux/spi/spi.h | 2 ++ 3 files changed, 6 insertions(+) diff --git a/Documentation/devicetree/bindings/spi/spi-bus.txt b/Documentation/devicetree/bindings/spi/spi-bus.txt index bbaa857..434d321 100644 --- a/Documentation/devicetree/bindings/spi/spi-bus.txt +++ b/Documentation/devicetree/bindings/spi/spi-bus.txt @@ -61,6 +61,8 @@ contain the following properties. used for MOSI. Defaults to 1 if not present. - spi-rx-bus-width - (optional) The bus width(number of data wires) that used for MISO. Defaults to 1 if not present. +- spi-word-wait-ns - (optional) Delay between transmission of words + in nanoseconds Some SPI controllers and devices support Dual and Quad SPI transfer mode. It allows data in the SPI system to be transferred in 2 wires(DUAL) or 4 wires(QUAD). diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 2b0a8ec..186373b 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -1467,6 +1467,8 @@ of_register_spi_device(struct spi_master *master, struct device_node *nc) if (of_find_property(nc, "spi-lsb-first", NULL)) spi->mode |= SPI_LSB_FIRST; + of_property_read_u32(nc, "spi-word-wait-ns", &spi->word_wait_ns); + /* Device DUAL/QUAD mode */ if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) { switch (value) { diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index cce80e6..ea3037f 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -118,6 +118,7 @@ void spi_statistics_add_transfer_stats(struct spi_statistics *stats, * for driver coldplugging, and in uevents used for hotplugging * @cs_gpio: gpio number of the chipselect line (optional, -ENOENT when * when not using a GPIO line) + * @word_wait_ns: A wait time between word transfers in nanoseconds * * @statistics: statistics for the spi_device * @@ -158,6 +159,7 @@ struct spi_device { void *controller_data; char modalias[SPI_NAME_SIZE]; int cs_gpio; /* chip select gpio */ + u32 word_wait_ns; /* wait time between words */ /* the statistics */ struct spi_statistics statistics; -- 1.9.1