usb rpi: get rid of local hardware timer

We used a hardware timer locally in the RPI USB driver because a timer
connection was not precise enough to fullfill the host controllers
requirements.

With the modern timer connection interface, however, reading out time at
a connection is microseconds precise and we can remove the local timer.
But we cannot use the same timer connection for doing legacy-interface
stuff like usleep (currently used in LX kit) and modern-interface stuff
like curr_time. Thus, we open two connections for now.

Ref #2400

repos/dde_linux/src/include/lx_kit/timer.h

@@ -38,9 +38,6 @@ namespace Lx {
 	             unsigned long      *jiffies_ptr = nullptr);
 
 	void timer_update_jiffies();
-
-	typedef unsigned long (*jiffies_update_func)(void);
-	void register_jiffies_func(jiffies_update_func func);
 }
 
 

repos/dde_linux/src/lib/usb/spec/rpi/platform.cc

@@ -12,7 +12,6 @@
  */
 
 /* Genode includes */
-#include <base/attached_io_mem_dataspace.h>
 #include <io_mem_session/connection.h>
 #include <util/mmio.h>
 #include <platform_session/connection.h>
@@ -21,8 +20,7 @@
 /* emulation */
 #include <platform.h>
 #include <lx_emul.h>
-#include <lx_kit/timer.h>
+#include <timer_session/connection.h>
-
 
 /* dwc-otg */
 #define new new_
@@ -31,124 +29,9 @@
 
 using namespace Genode;
 
-namespace Genode { template <unsigned long> class Sp804_base; }
-
 unsigned dwc_irq();
 
 
-/**
- * Basic driver for the ARM SP804 timer
- */
-template <unsigned long CLK>
-class Genode::Sp804_base : public Mmio
-{
-	enum {
-		TICS_PER_MS = CLK / 1000,
-	};
-
-	/**
-	 * Holds value that shall be loaded to the timer value register
-	 */
-	struct Load : Register<0x0, 32> { };
-
-	/**
-	 * Timer value register
-	 */
-	struct Value : Register<0x4, 32> { enum { MAX_VALUE = 0xffffffff }; };
-
-	/**
-	 * Timer control register
-	 */
-	struct Control : Register<0x8, 8>
-	{
-		struct Oneshot  : Bitfield<0,1> { };
-		struct Size     : Bitfield<1,1> { };
-		struct Pre      : Bitfield<2,2> { };
-		struct Int_en   : Bitfield<5,1> { };
-		struct Mode     : Bitfield<6,1> { };
-		struct Timer_en : Bitfield<7,1> { };
-	};
-
-	/**
-	 * Clears the timer interrupt
-	 */
-	struct Int_clr : Register<0xc, 1> { };
-
-	unsigned _last_tick = Value::MAX_VALUE;
-
-	public:
-
-		/**
-		 * Constructor, clears interrupt output
-		 */
-		Sp804_base(addr_t const mmio_base) : Mmio(mmio_base)
-		{
-			/* clear irq */
-			write<Int_clr>(1);
-
-			/* disabble and configure */
-			write<typename Control::Timer_en>(0);
-			write<Control>(Control::Mode::bits(0)     | /* free running */
-			               Control::Int_en::bits(0)   | /* IRQ disabled */
-			               Control::Pre::bits(0)      | /* clk divider 1 */
-			               Control::Size::bits(1)     | /* 32 bit */
-			               Control::Oneshot::bits(0));  /* one-shot off */
-
-			/* start */
-			write<Load>(Value::MAX_VALUE);
-			write<typename Control::Timer_en>(1);
-		}
-
-		unsigned long update_jiffies()
-		{
-			unsigned tick = read<Value>();
-
-			/* timer runs backwards */
-			unsigned delta = ticks_to_ms(_last_tick - tick);
-
-			/* delta < 1 jiffie */
-			if (!msecs_to_jiffies(delta))
-				return jiffies;
-
-			jiffies   += msecs_to_jiffies(delta);
-			_last_tick = tick;
-			return jiffies;
-		}
-
-		/**
-		 * Translate native timer value to milliseconds
-		 */
-		static unsigned long ticks_to_ms(unsigned long const tics) {
-			return tics / TICS_PER_MS; }
-};
-
-
-enum { TIMER_MMIO_BASE   = 0x2000b400,
-       TIMER_MMIO_SIZE   = 0x100,
-       TIMER_CLOCK       = 992*1000 };
-
-struct Platform_timer : Attached_io_mem_dataspace,
-                        Sp804_base<TIMER_CLOCK>
-{
-	Platform_timer() :
-		Attached_io_mem_dataspace(TIMER_MMIO_BASE, TIMER_MMIO_SIZE),
-		Sp804_base((Genode::addr_t)local_addr<void>())
-	{ }
-
-	static Platform_timer &instance()
-	{
-		static Platform_timer _timer;
-		return _timer;
-	}
-};
-
-
-static unsigned long jiffies_update_func()
-{
-	return Platform_timer::instance().update_jiffies();
-}
-
-
 /************************************************
  ** Resource info passed to the dwc_otg driver **
  ************************************************/
@@ -280,12 +163,6 @@ extern "C" int  module_smsc95xx_driver_init();
 
 void platform_hcd_init(Services *services)
 {
-	/* enable timer */
-	Platform_timer::instance();
-
-	/* use costum jiffies update function and the Sp804 timer */
-	Lx::register_jiffies_func(jiffies_update_func);
-
 	/* enable USB power */
 	Platform::Connection platform;
 	platform.power_state(Platform::Session::POWER_USB_HCD, true);

repos/dde_linux/src/lx_kit/timer.cc

@@ -81,11 +81,11 @@ class Lx_kit::Timer : public Lx::Timer
 
 		unsigned long                               &_jiffies;
 		::Timer::Connection                          _timer_conn;
+		::Timer::Connection                          _timer_conn_modern;
 		Lx_kit::List<Context>                        _list;
 		Lx::Task                                     _timer_task;
 		Genode::Signal_handler<Lx_kit::Timer>        _dispatcher;
 		Genode::Tslab<Context, 32 * sizeof(Context)> _timer_alloc;
-		Lx::jiffies_update_func                      _jiffies_func = nullptr;
 
 		/**
 		 * Lookup local timer
@@ -177,6 +177,7 @@ class Lx_kit::Timer : public Lx::Timer
 		:
 			_jiffies(jiffies),
 			_timer_conn(env),
+			_timer_conn_modern(env),
 			_timer_task(Timer::run_timer, reinterpret_cast<void*>(this),
 			            "timer", Lx::Task::PRIORITY_2, Lx::scheduler()),
 			_dispatcher(ep, *this, &Lx_kit::Timer::_handle),
@@ -292,10 +293,7 @@ class Lx_kit::Timer : public Lx::Timer
 		}
 
 		void update_jiffies() {
-			_jiffies = _jiffies_func ? _jiffies_func() : msecs_to_jiffies(_timer_conn.elapsed_ms()); }
+			_jiffies = usecs_to_jiffies(_timer_conn_modern.curr_time().trunc_to_plain_us().value); }
-
-		void register_jiffies_func(Lx::jiffies_update_func func) {
-			_jiffies_func = func; }
 
 		void usleep(unsigned us) {
 			_timer_conn.usleep(us); }
@@ -319,9 +317,3 @@ void Lx::timer_update_jiffies()
 {
 	timer().update_jiffies();
 }
-
-
-void Lx::register_jiffies_func(jiffies_update_func func)
-{
-	dynamic_cast<Lx_kit::Timer &>(timer()).register_jiffies_func(func);
-}