+/* This is used to make sure the power-button pusher is serious. The button
+ * must be held until the value of this counter reaches zero.
+ */
+static int power_button_countdown;
+
+/* Must hold the button down for at least this many counts to be processed */
+#define PBUTTON_HOLDDOWN_COUNT 4 /* 2 secs */
+
+static void dsmg600_power_handler(unsigned long data);
+static DEFINE_TIMER(dsmg600_power_timer, dsmg600_power_handler, 0, 0);
+
+static void dsmg600_power_handler(unsigned long data)
+{
+ /* This routine is called twice per second to check the
+ * state of the power button.
+ */
+
+ if (gpio_get_value(DSMG600_PB_GPIO)) {
+
+ /* IO Pin is 1 (button pushed) */
+ if (power_button_countdown > 0)
+ power_button_countdown--;
+
+ } else {
+
+ /* Done on button release, to allow for auto-power-on mods. */
+ if (power_button_countdown == 0) {
+ /* Signal init to do the ctrlaltdel action,
+ * this will bypass init if it hasn't started
+ * and do a kernel_restart.
+ */
+ ctrl_alt_del();
+
+ /* Change the state of the power LED to "blink" */
+ gpio_line_set(DSMG600_LED_PWR_GPIO, IXP4XX_GPIO_LOW);
+ } else {
+ power_button_countdown = PBUTTON_HOLDDOWN_COUNT;
+ }
+ }
+
+ mod_timer(&dsmg600_power_timer, jiffies + msecs_to_jiffies(500));
+}
+
+static irqreturn_t dsmg600_reset_handler(int irq, void *dev_id)
+{
+ /* This is the paper-clip reset, it shuts the machine down directly. */
+ machine_power_off();
+
+ return IRQ_HANDLED;
+}
+