From 01e1e4e5b91084b3bf303f9c4ce45a7f44c85964 Mon Sep 17 00:00:00 2001
From: Stefan Kalkowski <stefan.kalkowski@genode-labs.com>
Date: Thu, 27 Oct 2022 14:37:42 +0200
Subject: [PATCH] platform_drv: add "leave_operational" attribute

If a device should not be reset, powered off, and its clocks
shall stay untouched when it gets released, the leave_operational
attribute can be set to true in the device node of the related
device inside the devices ROM delivered to the platform driver.
This is useful for drivers, which only enable and initialize
their device, and can be closed afterwards.

Ref genodelabs/genode#4654
---
 repos/os/src/drivers/platform/device.cc       | 41 +++++++++++--------
 repos/os/src/drivers/platform/device.h        |  4 +-
 .../drivers/platform/device_model_policy.cc   |  3 +-
 3 files changed, 28 insertions(+), 20 deletions(-)

diff --git a/repos/os/src/drivers/platform/device.cc b/repos/os/src/drivers/platform/device.cc
index 082d0d8a4b..a4a83e0181 100644
--- a/repos/os/src/drivers/platform/device.cc
+++ b/repos/os/src/drivers/platform/device.cc
@@ -92,25 +92,27 @@ void Driver::Device::release(Session_component & sc)
 	if (!(_owner == sc))
 		return;
 
-	pci_disable(_env, *this);
+	if (!_leave_operational) {
+		pci_disable(_env, *this);
 
-	_reset_domain_list.for_each([&] (Reset_domain & r)
-	{
-		_model.resets().apply(r.name, [&] (Driver::Reset &reset) {
-			reset.assert(); });
-	});
+		_reset_domain_list.for_each([&] (Reset_domain & r)
+		{
+			_model.resets().apply(r.name, [&] (Driver::Reset &reset) {
+				reset.assert(); });
+		});
 
-	_power_domain_list.for_each([&] (Power_domain & p)
-	{
-		_model.powers().apply(p.name, [&] (Driver::Power &power) {
-			power.off(); });
-	});
+		_power_domain_list.for_each([&] (Power_domain & p)
+		{
+			_model.powers().apply(p.name, [&] (Driver::Power &power) {
+				power.off(); });
+		});
 
-	_clock_list.for_each([&] (Clock & c)
-	{
-		_model.clocks().apply(c.name, [&] (Driver::Clock &clock) {
-			clock.disable(); });
-	});
+		_clock_list.for_each([&] (Clock & c)
+		{
+			_model.clocks().apply(c.name, [&] (Driver::Clock &clock) {
+				clock.disable(); });
+		});
+	}
 
 	_owner = Owner();
 	sc.update_devices_rom();
@@ -181,8 +183,11 @@ void Driver::Device::generate(Xml_generator & xml, bool info) const
 }
 
 
-Driver::Device::Device(Env & env, Device_model & model, Name name, Type type)
-: _env(env), _model(model), _name(name), _type(type) { }
+Driver::Device::Device(Env & env, Device_model & model, Name name, Type type,
+                       bool leave_operational)
+:
+	_env(env), _model(model), _name(name), _type(type),
+	_leave_operational(leave_operational) { }
 
 
 Driver::Device::~Device()
diff --git a/repos/os/src/drivers/platform/device.h b/repos/os/src/drivers/platform/device.h
index 267c1d50f6..029162e1ab 100644
--- a/repos/os/src/drivers/platform/device.h
+++ b/repos/os/src/drivers/platform/device.h
@@ -210,7 +210,8 @@ class Driver::Device : private List_model<Device>::Element
 			Reserved_memory(Range range) : range(range) {}
 		};
 
-		Device(Env & env, Device_model & model, Name name, Type type);
+		Device(Env & env, Device_model & model, Name name, Type type,
+		       bool leave_operational);
 		virtual ~Device();
 
 		Name  name()  const;
@@ -279,6 +280,7 @@ class Driver::Device : private List_model<Device>::Element
 		Device_model              & _model;
 		Name                  const _name;
 		Type                  const _type;
+		bool                  const _leave_operational;
 		Owner                       _owner {};
 		List_model<Io_mem>          _io_mem_list {};
 		List_model<Irq>             _irq_list {};
diff --git a/repos/os/src/drivers/platform/device_model_policy.cc b/repos/os/src/drivers/platform/device_model_policy.cc
index 45a04d8321..cb8745395a 100644
--- a/repos/os/src/drivers/platform/device_model_policy.cc
+++ b/repos/os/src/drivers/platform/device_model_policy.cc
@@ -71,7 +71,8 @@ Device & Device_model::create_element(Genode::Xml_node node)
 {
 	Device::Name name = node.attribute_value("name", Device::Name());
 	Device::Type type = node.attribute_value("type", Device::Type());
-	return *(new (_heap) Device(_env, *this, name, type));
+	bool leave_operational = node.attribute_value("leave_operational", false);
+	return *(new (_heap) Device(_env, *this, name, type, leave_operational));
 }