greybus: arche-platform: Add support for init-off feature

Disable wake_detect interrupt after request

As part of SW-4344/SW-7061, now we are enabling FW flashing
to all builds. That means check for need of FW upgrade is
going to be present in all builds, and moving to FW_FlASHING
mode from active is heavy operation; so the idea here is
simplify this process and save the boot time due to switching
back-n-forth between ACTIVE<=>FW_FLASHING modes.

So we decided to put unipro into OFF state by default on boot,
which can be changed through DT property. If arche-platform
device node has "arche,init-off" property set, then unipro
will be in OFF state on boot. User can bring it back by

 # echo active > /sys/devices/arche_platform*/state

And to simply the exit code of probe() fn the
arche_platform_coldboot_seq() has been shifted to the
bottom of the _probe() fn.

Testing Done: Tested on EVT2 platform, with and without
"arche,init-off" property, multiple times.
Note: I am seeing SW-7128, which is not related to these changes.
Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Tested-by: Michael Scott <michael.scott@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/staging/greybus/arche-platform.c

@@ -672,8 +672,7 @@ static int arche_platform_probe(struct platform_device *pdev)
 		dev_err(dev, "failed to request wake detect IRQ %d\n", ret);
 		return ret;
 	}
-
-	gpio_direction_input(arche_pdata->wake_detect_gpio);
+	disable_irq(arche_pdata->wake_detect_irq);
 
 	ret = device_create_file(dev, &dev_attr_state);
 	if (ret) {
@@ -681,38 +680,41 @@ static int arche_platform_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	mutex_lock(&arche_pdata->platform_state_mutex);
-	ret = arche_platform_coldboot_seq(arche_pdata);
-	if (ret) {
-		dev_err(dev, "Failed to cold boot svc %d\n", ret);
-		goto err_coldboot;
-	}
-
 	ret = of_platform_populate(np, NULL, NULL, dev);
 	if (ret) {
 		dev_err(dev, "failed to populate child nodes %d\n", ret);
-		goto err_populate;
+		goto err_device_remove;
 	}
 
 	arche_pdata->pm_notifier.notifier_call = arche_platform_pm_notifier;
 	ret = register_pm_notifier(&arche_pdata->pm_notifier);
-	mutex_unlock(&arche_pdata->platform_state_mutex);
 
 	if (ret) {
 		dev_err(dev, "failed to register pm notifier %d\n", ret);
-		goto err_populate;
+		goto err_device_remove;
 	}
 
 	/* Register callback pointer */
 	arche_platform_change_state_cb = arche_platform_change_state;
 
+	/* Explicitly power off if requested */
+	if (!of_property_read_bool(pdev->dev.of_node, "arche,init-off")) {
+		mutex_lock(&arche_pdata->platform_state_mutex);
+		ret = arche_platform_coldboot_seq(arche_pdata);
+		if (ret) {
+			dev_err(dev, "Failed to cold boot svc %d\n", ret);
+			goto err_coldboot;
+		}
+		arche_platform_wd_irq_en(arche_pdata);
+		mutex_unlock(&arche_pdata->platform_state_mutex);
+	}
+
 	dev_info(dev, "Device registered successfully\n");
 	return 0;
 
-err_populate:
-	arche_platform_poweroff_seq(arche_pdata);
 err_coldboot:
 	mutex_unlock(&arche_pdata->platform_state_mutex);
+err_device_remove:
 	device_remove_file(&pdev->dev, &dev_attr_state);
 	return ret;
 }