sunxi: Add option to prevent booting on power plug-in

For sunxi boards with the AXP209, AXP221, AXP809, and AXP818 PMICs
(plus possibly others, I only confirmed the datasheets for these),
it is sometimes desirable to not boot whenever the device is
plugged in. An example would be when using the NTC CHIP inside a
PocketCHIP.
This provides a configurable option to check if bit 0 of
register 0 of the PMIC says it was powered because of a power button
press (0) or a plug-in event (1). If the value is 1 and this option
is selected, the device shuts down shortly after printing a message
to console stating the reason why it's shutting down. Powering up the
board with the power button is not affected.

Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
[Andre: reword to speak of boot, remove #ifdefs]
Signed-off-by: Andre Przywara <andre.przywara@arm.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/arch/arm/mach-sunxi/Kconfig b/arch/arm/mach-sunxi/Kconfig
index 2c18cf02d1..d7f9a03152 100644
--- a/arch/arm/mach-sunxi/Kconfig
+++ b/arch/arm/mach-sunxi/Kconfig
@@ -785,6 +785,16 @@ config AXP_GPIO
 	---help---
 	Say Y here to enable support for the gpio pins of the axp PMIC ICs.
 
+config AXP_DISABLE_BOOT_ON_POWERON
+	bool "Disable device boot on power plug-in"
+	depends on AXP209_POWER || AXP221_POWER || AXP809_POWER || AXP818_POWER
+	default n
+	---help---
+	  Say Y here to prevent the device from booting up because of a plug-in
+	  event. When set, the device will boot into the SPL briefly to
+	  determine why it was powered on, and if it was determined because of
+	  a plug-in event instead of a button press event it will shut back off.
+
 config VIDEO_SUNXI
 	bool "Enable graphical uboot console on HDMI, LCD or VGA"
 	depends on !MACH_SUN8I_A83T