[PATCH] spi: add "spi-lsb-first" to devicetree
Baruch Siach
baruch at tkos.co.il
Tue Apr 1 19:42:56 EST 2014
Hi Zhao Qiang,
On Tue, Apr 01, 2014 at 03:55:31PM +0800, Zhao Qiang wrote:
> add optional property devicetree for SPI slave nodes
> into devicetree so that LSB mode can be enabled by devicetree.
>
> Signed-off-by: Zhao Qiang <B45475 at freescale.com>
> ---
> Documentation/devicetree/bindings/spi/spi-bus.txt | 4 ++++
> drivers/spi/spi.c | 2 ++
> 2 files changed, 6 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/spi/spi-bus.txt b/Documentation/devicetree/bindings/spi/spi-bus.txt
> index e5a4d1b..fdd9f15 100644
> --- a/Documentation/devicetree/bindings/spi/spi-bus.txt
> +++ b/Documentation/devicetree/bindings/spi/spi-bus.txt
> @@ -55,11 +55,15 @@ contain the following properties.
> chip select active high
> - spi-3wire - (optional) Empty property indicating device requires
> 3-wire mode.
> +- spi-lsb-first - (optional) Empty property indicating device requires
> + LSB first mode.
> - spi-tx-bus-width - (optional) The bus width(number of data wires) that
> 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-rx-bus-width - (optional) The bus width(number of data wires) that
> + used for MISO. Defaults to 1 if not present.
Is this part intentionally here? It is not mentioned in the commit log, and
seems to merit a separate patch.
baruch
> Some SPI controllers and devices support Dual and Quad SPI transfer mode.
> It allows data in SPI system transfered in 2 wires(DUAL) or 4 wires(QUAD).
> Now the value that spi-tx-bus-width and spi-rx-bus-width can receive is
> diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
> index 23756b0..0a20a90 100644
> --- a/drivers/spi/spi.c
> +++ b/drivers/spi/spi.c
> @@ -1050,6 +1050,8 @@ static void of_register_spi_devices(struct spi_master *master)
> spi->mode |= SPI_CS_HIGH;
> if (of_find_property(nc, "spi-3wire", NULL))
> spi->mode |= SPI_3WIRE;
> + if (of_find_property(nc, "spi-lsb-first", NULL))
> + spi->mode |= SPI_LSB_FIRST;
>
> /* Device DUAL/QUAD mode */
> if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
--
http://baruch.siach.name/blog/ ~. .~ Tk Open Systems
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