Re: [PATCH] spi: add "spi-lsb-first" to devicetree
From: Baruch Siach <baruch@tkos.co.il>
Date: 2014-04-01 08:42:56
Also in:
linux-devicetree, linux-spi
Hi Zhao Qiang, On Tue, Apr 01, 2014 at 03:55:31PM +0800, Zhao Qiang wrote:
quoted hunk
add optional property devicetree for SPI slave nodes into devicetree so that LSB mode can be enabled by devicetree. Signed-off-by: Zhao Qiang <redacted> --- 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
quoted hunk
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 isdiff --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)) {
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