The Raspberry Pi firmware manages the power-down and reboot
process. To do this it installs a pm_power_off handler, causing
the gpio-poweroff module to abort the probe function.
This patch introduces a "force" DT property that overrides that
behaviour, and also adds a DT overlay to enable and control it.
Note that running in an active-low configuration (DT parameter
"active_low") requires a custom dt-blob.bin and probably won't
allow a reboot without switching off, so an external inversion
of the trigger signal may be preferable.
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
+#include <linux/of.h>
#include <linux/property.h>
#include <linux/gpio/consumer.h>
#include <linux/mod_devicetable.h>
{
bool input = false;
enum gpiod_flags flags;
+ bool force = false;
/* If a pm_power_off function has already been added, leave it alone */
- if (pm_power_off != NULL) {
+ force = of_property_read_bool(pdev->dev.of_node, "force");
+ if (!force && (pm_power_off != NULL)) {
dev_err(&pdev->dev,
"%s: pm_power_off function already registered\n",
__func__);