Commit a110f93d authored by wangyuhang's avatar wangyuhang Committed by Mark Brown
Browse files

spi: quad: fix the name of DT property 



spi: quad: fix the name of DT property in patch

The previous property name spi-tx-nbits and spi-rx-nbits looks not
human-readable. To make it consistent with other devices, using property
name spi-tx-bus-width and spi-rx-bus-width instead of the previous one
specify the number of data wires that spi controller will work in.
Add the specification in spi-bus.txt.

Signed-off-by: default avatarwangyuhang <wangyuhang2014@gmail.com>
Signed-off-by: default avatarMark Brown <broonie@linaro.org>
parent a822e99c

Documentation/devicetree/bindings/spi/spi-bus.txt

+10 −0
Original line number Diff line number Diff line
@@ -55,6 +55,16 @@ contain the following properties. 
    		chip select active high

- spi-3wire       - (optional) Empty property indicating device requires

    		    3-wire 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.



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

only 1(SINGLE), 2(DUAL) and 4(QUAD).

Dual/Quad mode is not allowed when 3-wire mode is used.



If a gpio chipselect is used for the SPI slave the gpio number will be passed

via the cs_gpio

drivers/spi/spi.c

+4 −4
Original line number Diff line number Diff line
@@ -870,7 +870,7 @@ static void of_register_spi_devices(struct spi_master *master) 
			spi->mode |= SPI_3WIRE;



		/* Device DUAL/QUAD mode */

		prop = of_get_property(nc, "spi-tx-nbits", &len);

		prop = of_get_property(nc, "spi-tx-bus-width", &len);

		if (prop && len == sizeof(*prop)) {

			switch (be32_to_cpup(prop)) {

			case SPI_NBITS_SINGLE:
@@ -883,14 +883,14 @@ static void of_register_spi_devices(struct spi_master *master) 
				break;

			default:

				dev_err(&master->dev,

					"spi-tx-nbits %d not supported\n",

					"spi-tx-bus-width %d not supported\n",

					be32_to_cpup(prop));

				spi_dev_put(spi);

				continue;

			}

		}



		prop = of_get_property(nc, "spi-rx-nbits", &len);

		prop = of_get_property(nc, "spi-rx-bus-width", &len);

		if (prop && len == sizeof(*prop)) {

			switch (be32_to_cpup(prop)) {

			case SPI_NBITS_SINGLE:
@@ -903,7 +903,7 @@ static void of_register_spi_devices(struct spi_master *master) 
				break;

			default:

				dev_err(&master->dev,

					"spi-rx-nbits %d not supported\n",

					"spi-rx-bus-width %d not supported\n",

					be32_to_cpup(prop));

				spi_dev_put(spi);

				continue;

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