From: Torsten Fleischer <torfl6749@xxxxxxxxx> Use an empty 'cs-gpios' property if a single device is connected which has no chip select. This refers to the discussion at https://lkml.org/lkml/2013/11/13/62. Signed-off-by: Torsten Fleischer <torfl6749@xxxxxxxxx> --- Documentation/devicetree/bindings/spi/spi-gpio.txt | 6 ++++-- drivers/spi/spi-gpio.c | 10 +++++++--- 2 files changed, 11 insertions(+), 5 deletions(-) diff --git a/Documentation/devicetree/bindings/spi/spi-gpio.txt b/Documentation/devicetree/bindings/spi/spi-gpio.txt index 8a824be..ad8795f 100644 --- a/Documentation/devicetree/bindings/spi/spi-gpio.txt +++ b/Documentation/devicetree/bindings/spi/spi-gpio.txt @@ -8,8 +8,10 @@ Required properties: - gpio-sck: GPIO spec for the SCK line to use - gpio-miso: GPIO spec for the MISO line to use - gpio-mosi: GPIO spec for the MOSI line to use - - cs-gpios: GPIOs to use for chipselect lines - - num-chipselects: number of chipselect lines + - cs-gpios: GPIOs to use for chipselect lines. Leave this property empty if + a single device with no chip select is connected. + - num-chipselects: Number of chipselect lines. Has to be "1" even if a single + device with no chip select is connected. Example: diff --git a/drivers/spi/spi-gpio.c b/drivers/spi/spi-gpio.c index 9f59553..b343818a 100644 --- a/drivers/spi/spi-gpio.c +++ b/drivers/spi/spi-gpio.c @@ -461,9 +461,13 @@ static int spi_gpio_probe(struct platform_device *pdev) * property of the node. */ - for (i = 0; i < SPI_N_CHIPSEL; i++) - spi_gpio->cs_gpios[i] = - of_get_named_gpio(np, "cs-gpios", i); + if ((SPI_N_CHIPSEL == 1) && + (of_gpio_named_count(np, "cs-gpios") == 0)) + spi_gpio->cs_gpios[0] = SPI_GPIO_NO_CHIPSELECT; + else + for (i = 0; i < SPI_N_CHIPSEL; i++) + spi_gpio->cs_gpios[i] = + of_get_named_gpio(np, "cs-gpios", i); } #endif -- 1.8.4.5 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
