[DeviceDrivers] Add CPU time

components/drivers/Kconfig

@@ -16,6 +16,30 @@ config RT_USING_HWTIMER
     bool "Using hardware timer device drivers"
     default n
 
+config RT_USING_CPUTIME
+    bool "Enable CPU time for high resolution clock counter"
+    default n
+    help
+        When enable this option, the BSP should provide a rt_clock_cputime_ops
+        for CPU time by:
+        clock_cpu_setops(const struct rt_clock_cputime_ops *ops);
+
+        Then developer can use high resolution clock counter with:
+
+        ts = clock_cpu_gettime(); 
+        /* The unit of clock_cpu_gettime() can be returned by */
+        unit = clock_cpu_getres(); /* number for nanosecond */
+
+if RT_USING_CPUTIME 
+    config RT_USING_CPUTIME_CORTEXM
+        bool "Use DWT for CPU time"
+        default y
+        depends on ARCH_ARM_CORTEX_M3 || ARCH_ARM_CORTEX_M4 || ARCH_ARM_CORTEX_M7
+        help
+            Some Cortex-M3/4/7 MCU has Data Watchpoint and Trace Register, use 
+            the cycle counter in DWT for CPU time.
+endif
+
 config RT_USING_I2C
     bool "Using I2C device drivers"
     default n

components/drivers/cputime/SConscript

@@ -0,0 +1,14 @@
+from building import *
+
+cwd     = GetCurrentDir()
+CPPPATH = [cwd + '/../include']
+src     = Split('''
+cputime.c
+''')
+
+if GetDepend('RT_USING_CPUTIME_CORTEXM'):
+    src += ['cputime_cortexm.c']
+
+group   = DefineGroup('DeviceDrivers', src, depend = ['RT_USING_CPUTIME'], CPPPATH = CPPPATH)
+
+Return('group')

components/drivers/cputime/cputime.c

@@ -0,0 +1,70 @@
+/*
+ * File      : cputime.h
+ * This file is part of RT-Thread RTOS
+ * COPYRIGHT (C) 2017, RT-Thread Development Team
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Change Logs:
+ * Date           Author            Notes
+ * 2017-12-23     Bernard           first version
+ */
+
+#include <rtdevice.h>
+#include <rtthread.h>
+
+static const struct rt_clock_cputime_ops *_cputime_ops  = RT_NULL;
+
+/**
+ * The clock_cpu_getres() function shall return the resolution of CPU time, the 
+ * number of nanosecond per tick.
+ */
+uint32_t clock_cpu_getres(void)
+{
+    if (_cputime_ops)
+        return _cputime_ops->cputime_getres();
+
+    rt_set_errno(-ENOSYS);
+    return 0;
+}
+
+/**
+ * The clock_cpu_gettime() function shall return the current value of cpu time tick.
+ */
+uint32_t clock_cpu_gettime(void)
+{
+    if (_cputime_ops)
+        return _cputime_ops->cputime_gettime();
+
+    rt_set_errno(-ENOSYS);
+    return 0;
+}
+
+/**
+ * The clock_cpu_seops() function shall set the ops of cpu time.
+ * 
+ * @return always return 0.
+ */
+int clock_cpu_setops(const struct rt_clock_cputime_ops *ops)
+{
+    _cputime_ops = ops;
+    if (ops)
+    {
+        RT_ASSERT(ops->cputime_getres  != RT_NULL);
+        RT_ASSERT(ops->cputime_gettime != RT_NULL);
+    }
+
+    return 0;
+}

components/drivers/cputime/cputime_cortexm.c

@@ -0,0 +1,66 @@
+/*
+ * File      : cputime_cortexm.c
+ * This file is part of RT-Thread RTOS
+ * COPYRIGHT (C) 2017, RT-Thread Development Team
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Change Logs:
+ * Date           Author            Notes
+ * 2017-12-23     Bernard           first version
+ */
+
+#include <rthw.h>
+#include <rtdevice.h>
+#include <rtthread.h>
+
+#include <board.h>
+
+/* Use Cycle counter of Data Watchpoint and Trace Register for CPU time */
+
+static uint32_t cortexm_cputime_getres(void)
+{
+    return (1000 * 1000 * 1000)/SystemCoreClock;
+}
+
+static uint32_t cortexm_cputime_gettime(void)
+{
+    return DWT->CYCCNT;
+}
+
+const static struct rt_clock_cputime_ops _cortexm_ops = 
+{
+    cortexm_cputime_getres,
+    cortexm_cputime_gettime
+};
+
+int cortexm_cputime_init(void)
+{
+    /* check support bit */
+    if ((DWT->CTRL & (1UL << DWT_CTRL_NOCYCCNT_Pos)) == 0) 
+    {
+        /* whether cycle counter not enabled */
+        if ((DWT->CTRL & (1UL << DWT_CTRL_CYCCNTENA_Pos)) == 0) 
+        {
+            /* enable cycle counter */
+            DWT->CTRL |= (1UL << DWT_CTRL_CYCCNTENA_Pos);
+        }
+
+        clock_cpu_setops(&_cortexm_ops);
+    }
+
+    return 0;
+}
+INIT_BOARD_EXPORT(cortexm_cputime_init);

components/drivers/include/drivers/cputime.h

@@ -0,0 +1,39 @@
+/*
+ * File      : cputime.h
+ * This file is part of RT-Thread RTOS
+ * COPYRIGHT (C) 2017, RT-Thread Development Team
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Change Logs:
+ * Date           Author            Notes
+ * 2017-12-23     Bernard           first version
+ */
+
+#ifndef CPUTIME_H__
+#define CPUTIME_H__
+
+struct rt_clock_cputime_ops
+{
+    uint32_t (*cputime_getres) (void);
+    uint32_t (*cputime_gettime)(void);
+};
+
+uint32_t clock_cpu_getres(void);
+uint32_t clock_cpu_gettime(void);
+
+int clock_cpu_setops(const struct rt_clock_cputime_ops *ops);
+
+#endif

components/drivers/include/rtdevice.h

@@ -108,6 +108,10 @@ extern "C" {
 #include "drivers/audio.h"
 #endif
 
+#ifdef RT_USING_CPUTIME
+#include "drivers/cputime.h"
+#endif
+
 #ifdef __cplusplus
 }
 #endif