greybus: hd: arche-platform: implement greybus shutdown

Implement platform driver shutdown callback to perform proper greybus
shutdown so that the userspace unipro_shutdown service that shuts down
the APB/SVC abruptly can be removed. The shutdown callback in
arche-platform will first remove SVC so that all the Interface can be
Deactivated in a sequence according to the spec before powering off the
APB:

Before:
 -> Arche/APB power off
 -> SoC power off

After this patch:
 -> HD shutdown
     -> SVC shutdown
         -> Module shutdown
             -> Interface shutdown
                 -> Bundle shutdown
 -> Arche/APB power off
 -> SoC power off

Testing Done:
 - Observe all Interfaces are deactivated in the log during shutdown
 - Measure power off current and make sure no regression

Signed-off-by: David Lin <dtwlin@google.com>
Reviewed-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Reviewed-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/staging/greybus/arche-apb-ctrl.c b/drivers/staging/greybus/arche-apb-ctrl.c
index fce6a187ecfe..cae56fc0a6e5 100644
--- a/drivers/staging/greybus/arche-apb-ctrl.c
+++ b/drivers/staging/greybus/arche-apb-ctrl.c
@@ -444,6 +444,11 @@ static int arche_apb_ctrl_resume(struct device *dev)
 	return 0;
 }
 
+static void arche_apb_ctrl_shutdown(struct platform_device *pdev)
+{
+	apb_ctrl_poweroff(&pdev->dev);
+}
+
 static SIMPLE_DEV_PM_OPS(arche_apb_ctrl_pm_ops, arche_apb_ctrl_suspend,
 			 arche_apb_ctrl_resume);
 
@@ -455,6 +460,7 @@ static struct of_device_id arche_apb_ctrl_of_match[] = {
 static struct platform_driver arche_apb_ctrl_device_driver = {
 	.probe		= arche_apb_ctrl_probe,
 	.remove		= arche_apb_ctrl_remove,
+	.shutdown	= arche_apb_ctrl_shutdown,
 	.driver		= {
 		.name	= "arche-apb-ctrl",
 		.pm	= &arche_apb_ctrl_pm_ops,