Diff: targets/TARGET_NUVOTON/TARGET_NUC472/lp_ticker.c

Revision:

153:9398a535854b

Parent:

152:9a67f0b066fc

diff -r 9a67f0b066fc -r 9398a535854b targets/TARGET_NUVOTON/TARGET_NUC472/lp_ticker.c
--- a/targets/TARGET_NUVOTON/TARGET_NUC472/lp_ticker.c	Thu Dec 15 11:48:27 2016 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,224 +0,0 @@
-/* mbed Microcontroller Library
- * Copyright (c) 2015-2016 Nuvoton
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
- 
-#include "lp_ticker_api.h"
-
-#if DEVICE_LOWPOWERTIMER
-
-#include "sleep_api.h"
-#include "nu_modutil.h"
-#include "nu_miscutil.h"
-#include "critical.h"
-
-// lp_ticker tick = us = timestamp
-#define US_PER_TICK             (1)
-#define US_PER_SEC              (1000 * 1000)
-
-#define US_PER_TMR2_INT         (US_PER_SEC * 10)
-#define TMR2_CLK_PER_SEC        (__LXT)
-#define TMR2_CLK_PER_TMR2_INT   ((uint32_t) ((uint64_t) US_PER_TMR2_INT * TMR2_CLK_PER_SEC / US_PER_SEC))
-#define TMR3_CLK_PER_SEC        (__LXT)
-
-static void tmr2_vec(void);
-static void tmr3_vec(void);
-static void lp_ticker_arm_cd(void);
-
-static int lp_ticker_inited = 0;
-static volatile uint32_t counter_major = 0;
-static volatile uint32_t cd_major_minor_clks = 0;
-static volatile uint32_t cd_minor_clks = 0;
-static volatile uint32_t wakeup_tick = (uint32_t) -1;
-
-// NOTE: To wake the system from power down mode, timer clock source must be ether LXT or LIRC.
-// NOTE: TIMER_2 for normal counting and TIMER_3 for scheduled wakeup
-static const struct nu_modinit_s timer2_modinit = {TIMER_2, TMR2_MODULE, CLK_CLKSEL1_TMR2SEL_LXT, 0, TMR2_RST, TMR2_IRQn, (void *) tmr2_vec};
-static const struct nu_modinit_s timer3_modinit = {TIMER_3, TMR3_MODULE, CLK_CLKSEL1_TMR3SEL_LXT, 0, TMR3_RST, TMR3_IRQn, (void *) tmr3_vec};
-
-#define TMR_CMP_MIN         2
-#define TMR_CMP_MAX         0xFFFFFFu
-
-void lp_ticker_init(void)
-{
-    if (lp_ticker_inited) {
-        return;
-    }
-    lp_ticker_inited = 1;
-    
-    counter_major = 0;
-    cd_major_minor_clks = 0;
-    cd_minor_clks = 0;
-    wakeup_tick = (uint32_t) -1;
-
-    // Reset module
-    SYS_ResetModule(timer2_modinit.rsetidx);
-    SYS_ResetModule(timer3_modinit.rsetidx);
-    
-    // Select IP clock source
-    CLK_SetModuleClock(timer2_modinit.clkidx, timer2_modinit.clksrc, timer2_modinit.clkdiv);
-    CLK_SetModuleClock(timer3_modinit.clkidx, timer3_modinit.clksrc, timer3_modinit.clkdiv);
-    // Enable IP clock
-    CLK_EnableModuleClock(timer2_modinit.clkidx);
-    CLK_EnableModuleClock(timer3_modinit.clkidx);
-
-    // Configure clock
-    uint32_t clk_timer2 = TIMER_GetModuleClock((TIMER_T *) NU_MODBASE(timer2_modinit.modname));
-    uint32_t prescale_timer2 = clk_timer2 / TMR2_CLK_PER_SEC - 1;
-    MBED_ASSERT((prescale_timer2 != (uint32_t) -1) && prescale_timer2 <= 127);
-    MBED_ASSERT((clk_timer2 % TMR2_CLK_PER_SEC) == 0);
-    uint32_t cmp_timer2 = TMR2_CLK_PER_TMR2_INT;
-    MBED_ASSERT(cmp_timer2 >= TMR_CMP_MIN && cmp_timer2 <= TMR_CMP_MAX);
-    // Continuous mode
-    ((TIMER_T *) NU_MODBASE(timer2_modinit.modname))->CTL = TIMER_PERIODIC_MODE | prescale_timer2 | TIMER_CTL_CNTDATEN_Msk;
-    ((TIMER_T *) NU_MODBASE(timer2_modinit.modname))->CMP = cmp_timer2;
-    
-    // Set vector
-    NVIC_SetVector(timer2_modinit.irq_n, (uint32_t) timer2_modinit.var);
-    NVIC_SetVector(timer3_modinit.irq_n, (uint32_t) timer3_modinit.var);
-    
-    NVIC_EnableIRQ(timer2_modinit.irq_n);
-    NVIC_EnableIRQ(timer3_modinit.irq_n);
-    
-    TIMER_EnableInt((TIMER_T *) NU_MODBASE(timer2_modinit.modname));
-    TIMER_EnableWakeup((TIMER_T *) NU_MODBASE(timer2_modinit.modname));
-    
-    // Schedule wakeup to match semantics of lp_ticker_get_compare_match()
-    lp_ticker_set_interrupt(wakeup_tick);
-    
-    // Start timer
-    TIMER_Start((TIMER_T *) NU_MODBASE(timer2_modinit.modname));
-}
-
-timestamp_t lp_ticker_read()
-{    
-    if (! lp_ticker_inited) {
-        lp_ticker_init();
-    }
-    
-    TIMER_T * timer2_base = (TIMER_T *) NU_MODBASE(timer2_modinit.modname);
-    
-    do {
-        uint64_t major_minor_clks;
-        uint32_t minor_clks;
-        
-        // NOTE: As TIMER_CNT = TIMER_CMP and counter_major has increased by one, TIMER_CNT doesn't change to 0 for one tick time.
-        // NOTE: As TIMER_CNT = TIMER_CMP or TIMER_CNT = 0, counter_major (ISR) may not sync with TIMER_CNT. So skip and fetch stable one at the cost of 1 clock delay on this read.
-        do {
-            core_util_critical_section_enter();
-        
-            // NOTE: Order of reading minor_us/carry here is significant.
-            minor_clks = TIMER_GetCounter(timer2_base);
-            uint32_t carry = (timer2_base->INTSTS & TIMER_INTSTS_TIF_Msk) ? 1 : 0;
-            // When TIMER_CNT approaches TIMER_CMP and will wrap soon, we may get carry but TIMER_CNT not wrapped. Hanlde carefully carry == 1 && TIMER_CNT is near TIMER_CMP.
-            if (carry && minor_clks > (TMR2_CLK_PER_TMR2_INT / 2)) {
-                major_minor_clks = (counter_major + 1) * TMR2_CLK_PER_TMR2_INT;
-            }
-            else {
-                major_minor_clks = (counter_major + carry) * TMR2_CLK_PER_TMR2_INT + minor_clks;
-            }
-            
-            core_util_critical_section_exit();
-        }
-        while (minor_clks == 0 || minor_clks == TMR2_CLK_PER_TMR2_INT);
-
-        // Add power-down compensation
-        return ((uint64_t) major_minor_clks * US_PER_SEC / TMR3_CLK_PER_SEC / US_PER_TICK);
-    }
-    while (0);
-}
-
-void lp_ticker_set_interrupt(timestamp_t timestamp)
-{
-    uint32_t now = lp_ticker_read();
-    wakeup_tick = timestamp;
-    
-    TIMER_Stop((TIMER_T *) NU_MODBASE(timer3_modinit.modname));
-    
-    /**
-     * FIXME: Scheduled alarm may go off incorrectly due to wrap around.
-     * Conditions in which delta is negative:
-     * 1. Wrap around
-     * 2. Newly scheduled alarm is behind now
-     */ 
-    //int delta = (timestamp > now) ? (timestamp - now) : (uint32_t) ((uint64_t) timestamp + 0xFFFFFFFFu - now);
-    int delta = (int) (timestamp - now);
-    if (delta > 0) {
-        cd_major_minor_clks = (uint64_t) delta * US_PER_TICK * TMR3_CLK_PER_SEC / US_PER_SEC;
-        lp_ticker_arm_cd();
-    }
-    else {
-        cd_major_minor_clks = cd_minor_clks = 0;
-        /**
-         * This event was in the past. Set the interrupt as pending, but don't process it here.
-         * This prevents a recurive loop under heavy load which can lead to a stack overflow.
-         */  
-        NVIC_SetPendingIRQ(timer3_modinit.irq_n);
-    }
-}
-
-void lp_ticker_disable_interrupt(void)
-{
-    TIMER_DisableInt((TIMER_T *) NU_MODBASE(timer3_modinit.modname));
-}
-
-void lp_ticker_clear_interrupt(void)
-{
-    TIMER_ClearIntFlag((TIMER_T *) NU_MODBASE(timer3_modinit.modname));
-}
-
-static void tmr2_vec(void)
-{
-    TIMER_ClearIntFlag((TIMER_T *) NU_MODBASE(timer2_modinit.modname));
-    TIMER_ClearWakeupFlag((TIMER_T *) NU_MODBASE(timer2_modinit.modname));
-    counter_major ++;
-}
-
-static void tmr3_vec(void)
-{
-    TIMER_ClearIntFlag((TIMER_T *) NU_MODBASE(timer3_modinit.modname));
-    TIMER_ClearWakeupFlag((TIMER_T *) NU_MODBASE(timer3_modinit.modname));
-    cd_major_minor_clks = (cd_major_minor_clks > cd_minor_clks) ? (cd_major_minor_clks - cd_minor_clks) : 0;
-    if (cd_major_minor_clks == 0) {
-        // NOTE: lp_ticker_set_interrupt() may get called in lp_ticker_irq_handler();
-        lp_ticker_irq_handler();
-    }
-    else {
-        lp_ticker_arm_cd();
-    }
-}
-
-static void lp_ticker_arm_cd(void)
-{
-    TIMER_T * timer3_base = (TIMER_T *) NU_MODBASE(timer3_modinit.modname);
-    
-    // Reset 8-bit PSC counter, 24-bit up counter value and CNTEN bit
-    timer3_base->CTL |= TIMER_CTL_RSTCNT_Msk;
-    // One-shot mode, Clock = 1 KHz 
-    uint32_t clk_timer3 = TIMER_GetModuleClock((TIMER_T *) NU_MODBASE(timer3_modinit.modname));
-    uint32_t prescale_timer3 = clk_timer3 / TMR3_CLK_PER_SEC - 1;
-    MBED_ASSERT((prescale_timer3 != (uint32_t) -1) && prescale_timer3 <= 127);
-    MBED_ASSERT((clk_timer3 % TMR3_CLK_PER_SEC) == 0);
-    timer3_base->CTL &= ~(TIMER_CTL_OPMODE_Msk | TIMER_CTL_PSC_Msk | TIMER_CTL_CNTDATEN_Msk);
-    timer3_base->CTL |= TIMER_ONESHOT_MODE | prescale_timer3 | TIMER_CTL_CNTDATEN_Msk;
-    
-    cd_minor_clks = cd_major_minor_clks;
-    cd_minor_clks = NU_CLAMP(cd_minor_clks, TMR_CMP_MIN, TMR_CMP_MAX);
-    timer3_base->CMP = cd_minor_clks;
-    
-    TIMER_EnableInt(timer3_base);
-    TIMER_EnableWakeup((TIMER_T *) NU_MODBASE(timer3_modinit.modname));
-    TIMER_Start(timer3_base);
-}
-#endif