gpio: raspberrypi-exp: Driver for RPi3 GPIO expander via mailbox service
Pi3 and Compute Module 3 have a GPIO expander that the
VPU communicates with.
There is a mailbox service that now allows control of this
expander, so add a kernel driver that can make use of it.
Reviewed-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 8dbb228..fd0562a 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -122,6 +122,15 @@
Select this option to enable GPIO driver for
Atheros AR71XX/AR724X/AR913X SoC devices.
+config GPIO_RASPBERRYPI_EXP
+ tristate "Raspberry Pi 3 GPIO Expander"
+ default RASPBERRYPI_FIRMWARE
+ depends on OF_GPIO
+ depends on (ARCH_BCM2835 && RASPBERRYPI_FIRMWARE) || COMPILE_TEST
+ help
+ Turn on GPIO support for the expander on Raspberry Pi 3 boards, using
+ the firmware mailbox to communicate with VideoCore on BCM283x chips.
+
config GPIO_BCM_KONA
bool "Broadcom Kona GPIO"
depends on OF_GPIO && (ARCH_BCM_MOBILE || COMPILE_TEST)