MCPGPIO(4) | Device Drivers Manual | MCPGPIO(4) |
mcpgpio
—
mcpgpio* at iic? addr ?
gpio* at gpiobus?
mcpgpio0 at spi? slave 0 flags 0
mcpgpio1 at spi? slave 0 flags 1
mcpgpio2 at spi? slave 0 flags 2
mcpgpio3 at spi? slave 0 flags 3
gpio* at gpiobus?
mcpgpio
driver supports the following Microchip I/O
Expanders:
Access to the pins is provided by the gpio(4) interface.
The SPI version of these devices support multiple chips per chip select signal. On the MCP23S08 and MCP23S17, this is achieved by tying the address select pins to VDD or GND to select an address (0-3 on MCP23S08 or 0-7 on MCP23S17). The MCP23S18 has a similar capability, but uses an analog voltage input on a single address select pin, along with an internal voltage divider ladder and a series of comparators to generate the 3 address bits; see the data sheet for details. The flags argument in the configuration directive for SPI attachments selects the hardware address of the chip instance for that driver instance.
mcpgpio
driver first appeared in
NetBSD 7.0. It was overhauled in
NetBSD 10.0 to support additional chip types and to
add the I2C attachment.
mcpgpio
driver was written by Frank
Kardel
<kardel@NetBSD.org>
and Jason R. Thorpe
<thorpej@NetBSD.org>.
mcpgpio
driver do not utilize the
Device Tree bindings for this device.
The mcpgpio
driver does not currently act
as a GPIO provider for the platform device tree.
January 10, 2022 | NetBSD 10.0 |