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-rw-r--r--include/linux/spi/spi_gpio.h6
1 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/spi/spi_gpio.h b/include/linux/spi/spi_gpio.h
index 0f01a0f1f40..ca6782ee4b9 100644
--- a/include/linux/spi/spi_gpio.h
+++ b/include/linux/spi/spi_gpio.h
@@ -25,10 +25,16 @@
* ...
* };
*
+ * If chipselect is not used (there's only one device on the bus), assign
+ * SPI_GPIO_NO_CHIPSELECT to the controller_data:
+ * .controller_data = (void *) SPI_GPIO_NO_CHIPSELECT;
+ *
* If the bitbanged bus is later switched to a "native" controller,
* that platform_device and controller_data should be removed.
*/
+#define SPI_GPIO_NO_CHIPSELECT ((unsigned long)-1l)
+
/**
* struct spi_gpio_platform_data - parameter for bitbanged SPI master
* @sck: number of the GPIO used for clock output