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NAMEgpiobus —
GPIO bus system
SYNOPSISTo compile these devices into your kernel and use the device hints, place the following lines in your kernel configuration file:device gpio
device gpioc
device gpioiic
device gpioled Additional device entries for the device a10_gpio
device bcm_gpio
device imx51_gpio
device lpcgpio
device mv_gpio
device ti_gpio
device gpio_avila
device gpio_cambria
device zy7_gpio
device pxagpio Additional device entries for the device ar71xxx_gpio
device octeon_gpio
device rt305_gpio Additional device entries for the device wiigpio
device macgpio Additional device entries for the device sifive_gpio DESCRIPTIONThegpiobus system provides a simple interface to the
GPIO pins that are usually available on embedded architectures and can provide
bit banging style devices to the system.
The acronym The BUS physically consists of multiple pins that can be configured for input/output, IRQ delivery, SDA/SCL iicbus use, etc. On some embedded architectures (like MIPS), discovery of the bus and configuration of the pins is done via device.hints(5) in the platform's kernel config(5) file. On some others (like ARM), where FDT(4) is used to describe the device tree, the bus discovery is done via the DTS passed to the kernel, being either statically compiled in, or by a variety of ways where the boot loader (or Open Firmware enabled system) passes the DTS blob to the kernel at boot. On a
device.hints(5)
based system these hints can be used to configure drivers for devices
attached to
The following
device.hints(5)
are only provided by the
Simply put, each pin of the GPIO interface is connected to an input/output of some device in a system. SEE ALSOgpioiic(4), gpioled(4), iicbus(4), device.hints(5), gpioctl(8)HISTORYThegpiobus manual page first appeared in
FreeBSD 10.0.
AUTHORSThis manual page was written by Sean Bruno <sbruno@FreeBSD.org>.
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