[U-Boot] [PATCH 3/6] spi: Support half-duplex mode in FDT decode

Ajay kumar ajaynumb at gmail.com
Tue Jul 8 08:11:39 CEST 2014


On Mon, Jul 7, 2014 at 9:46 PM, Simon Glass <sjg at chromium.org> wrote:
> This parameter should also be supported.
>
> Signed-off-by: Simon Glass <sjg at chromium.org>
> ---
>
>  doc/device-tree-bindings/spi/spi-bus.txt | 2 ++
>  drivers/spi/spi.c                        | 2 ++
>  2 files changed, 4 insertions(+)
>
> diff --git a/doc/device-tree-bindings/spi/spi-bus.txt b/doc/device-tree-bindings/spi/spi-bus.txt
> index 800dafe..5c8720a 100644
> --- a/doc/device-tree-bindings/spi/spi-bus.txt
> +++ b/doc/device-tree-bindings/spi/spi-bus.txt
> @@ -59,6 +59,8 @@ 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-half-duplex  - (optional) Indicates that the SPI bus should wait for
> +                     a header byte before reading data from the slave.
>
>  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).
> diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
> index 7ddea9b..7d81fbd 100644
> --- a/drivers/spi/spi.c
> +++ b/drivers/spi/spi.c
> @@ -53,6 +53,8 @@ struct spi_slave *spi_base_setup_slave_fdt(const void *blob, int busnum,
>                 mode |= SPI_CPHA;
>         if (fdtdec_get_bool(blob, node, "spi-cs-high"))
>                 mode |= SPI_CS_HIGH;
> +       if (fdtdec_get_bool(blob, node, "spi-half-duplex"))
> +               mode |= SPI_PREAMBLE;
>         return spi_setup_slave(busnum, cs, max_hz, mode);
>  }
>  #endif
> --
> 2.0.0.526.g5318336
>
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Able to test display on peach_pit(which needs tps65090) with these patches.
Also, crosec commands from u-boot prompt works as expected on peach_pit.

Tested-by: Ajay Kumar <ajaykumar.rs at samsung.com>


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