linux/spi/spi_gpio.h

5  * For each bitbanged SPI bus, set up a platform_device node with:
6  *   - name "spi_gpio"
7  *   - id the same as the SPI bus number it implements
8  *   - dev.platform data pointing to a struct spi_gpio_platform_data
15  * that the controller_data being the GPIO used for each device's
20  *		// this slave uses GPIO 42 for its chipselect
23  *		// this one uses GPIO 86 for its chipselect
39 #define SPI_GPIO_NO_CHIPSELECT		((unsigned long)-1l)
40 #define SPI_GPIO_NO_MISO		((unsigned long)-1l)
41 #define SPI_GPIO_NO_MOSI		((unsigned long)-1l)
44  * struct spi_gpio_platform_data - parameter for bitbanged SPI master
45  * @sck: number of the GPIO used for clock output
46  * @mosi: number of the GPIO used for Master Output, Slave In (MOSI) data
47  * @miso: number of the GPIO used for Master Input, Slave Output (MISO) data
50  * All GPIO signals used with the SPI bus managed through this driver
55  * functions associated with a "native" SPI controller if a driver for that
61  * drivers expect to see all-ones data as the no slave "response".)