From: Torsten Fleischer <torfl6...@gmail.com>
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 <torfl6...@gmail.com>
---
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 linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
