os & base-hw: freescale EPIT timer driver

Fix #576

os/src/drivers/timer/hw/epit/platform_timer_base.h

@@ -0,0 +1,117 @@
+/*
+ * \brief  Basic driver behind platform timer
+ * \author Stefan Kalkowski
+ * \date   2012-10-25
+ */
+
+/*
+ * Copyright (C) 2012 Genode Labs GmbH
+ *
+ * This file is part of the Genode OS framework, which is distributed
+ * under the terms of the GNU General Public License version 2.
+ */
+
+#ifndef _HW__EPIT__PLATFORM_TIMER_BASE_H_
+#define _HW__EPIT__PLATFORM_TIMER_BASE_H_
+
+/* Genode includes */
+#include <io_mem_session/connection.h>
+#include <util/mmio.h>
+#include <irq_session/connection.h>
+#include <drivers/board_base.h>
+#include <drivers/timer/epit_base.h>
+
+namespace Genode
+{
+	/**
+	 * Epit timer
+	 */
+	class Epit : public Epit_base
+	{
+		private:
+
+			/**
+			 * Timer tics per microsecond
+			 */
+			static float tics_per_us() {
+				return (float)TICS_PER_MS / 1000.0; }
+
+			/**
+			 * Microseconds per timer tic
+			 */
+			static float us_per_tic() { return 1.0 / tics_per_us(); }
+
+		public:
+
+			/**
+			 * Constructor
+			 *
+			 * \param base  MMIO base
+			 */
+			Epit(addr_t const base) : Epit_base(base) { }
+
+			/**
+			 * Count down 'value', raise IRQ output, wrap counter and continue
+			 */
+			void run_and_wrap(unsigned long value) {
+				start_one_shot(value); }
+
+			/**
+			 * Maximum timeout value
+			 */
+			unsigned long max_value() {
+				return read<Lr>(); }
+
+			/**
+			 * Translate timer tics to microseconds
+			 */
+			unsigned long tics_to_us(unsigned long const tics)
+			{
+				float const us = tics * us_per_tic();
+				return (unsigned long)us;
+			}
+
+			/**
+			 * Translate microseconds to timer tics
+			 */
+			unsigned long us_to_tics(unsigned long const us)
+			{
+				float const tics = us * tics_per_us();
+				return (unsigned long)tics;
+			}
+
+			/**
+			 * Sample the timer counter and according wrapped status
+			 */
+			unsigned long value(bool & wrapped)
+			{
+				unsigned long v = read<Cnt>();
+				wrapped = (bool)read<Sr::Ocif>();
+				return wrapped ? read<Cnt>() : v;
+			}
+	};
+}
+
+/**
+ * Basic driver behind platform timer
+ */
+class Platform_timer_base : public Genode::Io_mem_connection,
+                            public Genode::Epit
+{
+	public:
+
+	enum { IRQ = Genode::Board_base::EPIT_2_IRQ };
+
+		/**
+		 * Constructor
+		 */
+		Platform_timer_base()
+		: Io_mem_connection(Genode::Board_base::EPIT_2_MMIO_BASE,
+		                    Genode::Board_base::EPIT_2_MMIO_SIZE),
+		  Genode::Epit((Genode::addr_t)Genode::env()->rm_session()
+		                ->attach(dataspace()))
+		{ }
+};
+
+#endif /* _HW__EPIT__PLATFORM_TIMER_BASE_H_ */
+

os/src/drivers/timer/hw/epit/target.mk

@@ -0,0 +1,24 @@
+#
+# \brief   Timer session server
+# \author  Stefan Kalkowski
+# \date    2012-10-25
+#
+
+# set program name
+TARGET = timer
+
+# add C++ sources
+SRC_CC += main.cc
+
+# skip build if required specs not fullfilled
+REQUIRES += hw epit
+
+# add libraries
+LIBS += cxx server env alarm
+
+# add include paths
+INC_DIR += $(PRG_DIR) $(PRG_DIR)/../ $(PRG_DIR)/../../nova/
+
+# declare source paths
+vpath main.cc $(PRG_DIR)/../..
+