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>

diff --git a/arch/arm/mach-sunxi/Kconfig b/arch/arm/mach-sunxi/Kconfig
index 2c18cf0..d7f9a03 100644 (file)
--- 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

diff --git a/board/sunxi/board.c b/board/sunxi/board.c
index d0a93da..9146300 100644 (file)
--- a/board/sunxi/board.c
+++ b/board/sunxi/board.c
@@ -28,6 +28,7 @@
 #include <asm/arch/dram.h>
 #include <asm/arch/mmc.h>
 #include <asm/arch/prcm.h>
+#include <asm/arch/pmic_bus.h>
 #include <asm/arch/spl.h>
 #include <asm/global_data.h>
 #include <linux/delay.h>
@@ -602,6 +603,16 @@ void sunxi_board_init(void)
        defined CONFIG_AXP809_POWER || defined CONFIG_AXP818_POWER
        power_failed = axp_init();
 
+       if (IS_ENABLED(CONFIG_AXP_DISABLE_BOOT_ON_POWERON) && !power_failed) {
+               u8 boot_reason;
+
+               pmic_bus_read(AXP_POWER_STATUS, &boot_reason);
+               if (boot_reason & AXP_POWER_STATUS_ALDO_IN) {
+                       printf("Power on by plug-in, shutting down.\n");
+                       pmic_bus_write(0x32, BIT(7));
+               }
+       }
+
 #if defined CONFIG_AXP221_POWER || defined CONFIG_AXP809_POWER || \
        defined CONFIG_AXP818_POWER
        power_failed |= axp_set_dcdc1(CONFIG_AXP_DCDC1_VOLT);