imx8mq_platform_drv: introduce reset domains

A reset domain can consist of one or several reset-pins
denoted by name that are assigned to a device.
When the device gets acquired via the Platform RPC API,
the pins are de-asserted, and asserted again when the
device gets released.

A configuration looks like the following:

  <device name="mipi_dsi>
    <reset-domain name="mipi_dsi_pclk"/>
    ...
  </device>

Fixes #4171

repos/os/src/drivers/platform/imx8mq/device_model_policy.cc

@@ -47,6 +47,11 @@ void Device_model::destroy_element(Device & dev)
 		device._power_domain_list.destroy_all_elements(policy);
 	}
 
+	{
+		Reset_domain_update_policy policy(_env.heap);
+		device._reset_domain_list.destroy_all_elements(policy);
+	}
+
 	Genode::destroy(_env.heap, &device);
 }
 
@@ -88,4 +93,9 @@ void Device_model::update_element(Device & dev,
 		Power_domain_update_policy policy(_env.heap);
 		device._power_domain_list.update_from_xml(policy, node);
 	}
+
+	{
+		Reset_domain_update_policy policy(_env.heap);
+		device._reset_domain_list.update_from_xml(policy, node);
+	}
 }

repos/os/src/drivers/platform/imx8mq/env.h

@@ -20,6 +20,7 @@
 
 #include <ccm.h>
 #include <gpc.h>
+#include <src.h>
 #include <device.h>
 
 namespace Driver {
@@ -37,6 +38,7 @@ struct Driver::Env
 	Attached_rom_dataspace config      { env, "config"       };
 	Ccm                    ccm         { env                 };
 	Gpc                    gpc         { env                 };
+	Src                    src         { env                 };
 	Device_model           devices     { *this               };
 
 	Env(Genode::Env &env) : env(env) { }

repos/os/src/drivers/platform/imx8mq/imx_device.cc

@@ -23,6 +23,8 @@ bool Driver::Imx_device::acquire(Driver::Session_component & sc)
 	if (ret) {
 		_power_domain_list.for_each([&] (Power_domain & p) {
 			sc.env().gpc.enable(p.name); });
+		_reset_domain_list.for_each([&] (Reset_domain & r) {
+			sc.env().src.enable(r.name); });
 		_clock_list.for_each([&] (Clock & c) {
 			Avl_string_base * asb =
 				sc.env().ccm.tree.first()->find_by_name(c.name.string());
@@ -46,6 +48,8 @@ bool Driver::Imx_device::acquire(Driver::Session_component & sc)
 
 void Driver::Imx_device::release(Session_component & sc)
 {
+	_reset_domain_list.for_each([&] (Reset_domain & r) {
+		sc.env().src.disable(r.name); });
 	_power_domain_list.for_each([&] (Power_domain & p) {
 		sc.env().gpc.disable(p.name); });
 	_clock_list.for_each([&] (Clock & c) {

repos/os/src/drivers/platform/imx8mq/imx_device.h

@@ -22,6 +22,7 @@ namespace Driver {
 	class  Imx_device;
 	struct Clock_update_policy;
 	struct Power_domain_update_policy;
+	struct Reset_domain_update_policy;
 }
 
 
@@ -55,6 +56,15 @@ class Driver::Imx_device : public Driver::Device
 			Power_domain(Name name) : name(name) {}
 		};
 
+		struct Reset_domain : List_model<Reset_domain>::Element
+		{
+			using Name = Genode::String<64>;
+
+			Name name;
+
+			Reset_domain(Name name) : name(name) {}
+		};
+
 		bool acquire(Session_component &) override;
 		void release(Session_component &) override;
 
@@ -71,6 +81,7 @@ class Driver::Imx_device : public Driver::Device
 
 		List_model<Clock>        _clock_list {};
 		List_model<Power_domain> _power_domain_list {};
+		List_model<Reset_domain> _reset_domain_list {};
 };
 
 
@@ -138,4 +149,35 @@ struct Driver::Power_domain_update_policy
 	}
 };
 
+
+struct Driver::Reset_domain_update_policy
+: Genode::List_model<Imx_device::Reset_domain>::Update_policy
+{
+	Genode::Allocator & alloc;
+
+	Reset_domain_update_policy(Genode::Allocator & alloc) : alloc(alloc) {}
+
+	void destroy_element(Element & pd) {
+		Genode::destroy(alloc, &pd); }
+
+	Element & create_element(Genode::Xml_node node)
+	{
+		Element::Name name = node.attribute_value("name", Element::Name());
+		return *(new (alloc) Element(name));
+	}
+
+	void update_element(Element &, Genode::Xml_node) {}
+
+	static bool element_matches_xml_node(Element const & pd, Genode::Xml_node node)
+	{
+		Element::Name name = node.attribute_value("name", Element::Name());
+		return name == pd.name;
+	}
+
+	static bool node_is_element(Genode::Xml_node node)
+	{
+		return node.has_type("reset-domain");
+	}
+};
+
 #endif /* _SRC__DRIVERS__PLATFORM__IMX8MQ__IMX_DEVICE_H_ */

repos/os/src/drivers/platform/imx8mq/src.h

@@ -0,0 +1,58 @@
+/*
+ * \brief  System reset controller for i.MX8
+ * \author Stefan Kalkowski
+ * \date   2021-05-21
+ */
+
+/*
+ * Copyright (C) 2021 Genode Labs GmbH
+ *
+ * This file is part of the Genode OS framework, which is distributed
+ * under the terms of the GNU Affero General Public License version 3.
+ */
+
+#pragma once
+
+#include <base/env.h>
+#include <base/log.h>
+#include <os/attached_mmio.h>
+#include <util/string.h>
+
+struct Src : Genode::Attached_mmio
+{
+	struct Mipi_phy : Register<0x28, 32>
+	{
+		struct Byte  : Bitfield<1, 1> {};
+		struct Reset : Bitfield<2, 1> {};
+		struct Dpi   : Bitfield<3, 1> {};
+		struct Esc   : Bitfield<4, 1> {};
+		struct Pclk  : Bitfield<5, 1> {};
+	};
+
+	void enable(Genode::String<64> name)
+	{
+		if (name == "mipi_dsi_byte") { write<Mipi_phy::Byte>(1); return; }
+		if (name == "mipi_dsi_dpi")  { write<Mipi_phy::Dpi>(1);  return; }
+		if (name == "mipi_dsi_esc")  { write<Mipi_phy::Esc>(1);  return; }
+		if (name == "mipi_dsi_pclk") { write<Mipi_phy::Pclk>(1); return; }
+		warning("Reset domain ", name, " is unknown!");
+	}
+
+	void disable(Genode::String<64> name)
+	{
+		if (name == "mipi_dsi_byte") { write<Mipi_phy::Byte>(0); return; }
+		if (name == "mipi_dsi_dpi")  { write<Mipi_phy::Dpi>(0);  return; }
+		if (name == "mipi_dsi_esc")  { write<Mipi_phy::Esc>(0);  return; }
+		if (name == "mipi_dsi_pclk") { write<Mipi_phy::Pclk>(0); return; }
+		warning("Reset domain ", name, " is unknown!");
+	}
+
+	enum {
+		SRC_MMIO_BASE = 0x30390000,
+		SRC_MMIO_SIZE = 0x10000,
+	};
+
+	Src(Genode::Env & env)
+	: Attached_mmio(env, SRC_MMIO_BASE, SRC_MMIO_SIZE) { };
+};
+