mbed official / mbed-dev

mbed library sources. Supersedes mbed-src.

Dependents:   Nucleo_Hello_Encoder BLE_iBeaconScan AM1805_DEMO DISCO-F429ZI_ExportTemplate1 ... more

targets/TARGET_NUVOTON/TARGET_M480/lp_ticker.c@187:0387e8f68319, 2018-09-06 (annotated)

Committer:
AnnaBridge
Date:
Thu Sep 06 13:40:20 2018 +0100
Revision:
187:0387e8f68319
Parent:
186:707f6e361f3e
Child:
188:bcfe06ba3d64
mbed-dev library. Release version 163

Who changed what in which revision?

UserRevisionLine numberNew contents of line
AnnaBridge 172:7d866c31b3c5 1 /* mbed Microcontroller Library
AnnaBridge 172:7d866c31b3c5 2 * Copyright (c) 2015-2016 Nuvoton
AnnaBridge 172:7d866c31b3c5 3 *
AnnaBridge 172:7d866c31b3c5 4 * Licensed under the Apache License, Version 2.0 (the "License");
AnnaBridge 172:7d866c31b3c5 5 * you may not use this file except in compliance with the License.
AnnaBridge 172:7d866c31b3c5 6 * You may obtain a copy of the License at
AnnaBridge 172:7d866c31b3c5 7 *
AnnaBridge 172:7d866c31b3c5 8 * http://www.apache.org/licenses/LICENSE-2.0
AnnaBridge 172:7d866c31b3c5 9 *
AnnaBridge 172:7d866c31b3c5 10 * Unless required by applicable law or agreed to in writing, software
AnnaBridge 172:7d866c31b3c5 11 * distributed under the License is distributed on an "AS IS" BASIS,
AnnaBridge 172:7d866c31b3c5 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
AnnaBridge 172:7d866c31b3c5 13 * See the License for the specific language governing permissions and
AnnaBridge 172:7d866c31b3c5 14 * limitations under the License.
AnnaBridge 172:7d866c31b3c5 15 */
AnnaBridge 172:7d866c31b3c5 16
AnnaBridge 172:7d866c31b3c5 17 #include "lp_ticker_api.h"
AnnaBridge 172:7d866c31b3c5 18
Anna Bridge 186:707f6e361f3e 19 #if DEVICE_LPTICKER
AnnaBridge 172:7d866c31b3c5 20
AnnaBridge 172:7d866c31b3c5 21 #include "sleep_api.h"
AnnaBridge 182:a56a73fd2a6f 22 #include "mbed_wait_api.h"
AnnaBridge 182:a56a73fd2a6f 23 #include "mbed_assert.h"
AnnaBridge 172:7d866c31b3c5 24 #include "nu_modutil.h"
AnnaBridge 172:7d866c31b3c5 25 #include "nu_miscutil.h"
AnnaBridge 172:7d866c31b3c5 26
AnnaBridge 182:a56a73fd2a6f 27 /* Micro seconds per second */
AnnaBridge 182:a56a73fd2a6f 28 #define NU_US_PER_SEC 1000000
AnnaBridge 182:a56a73fd2a6f 29 /* Timer clock per lp_ticker tick */
AnnaBridge 182:a56a73fd2a6f 30 #define NU_TMRCLK_PER_TICK 1
AnnaBridge 182:a56a73fd2a6f 31 /* Timer clock per second */
AnnaBridge 182:a56a73fd2a6f 32 #define NU_TMRCLK_PER_SEC (__LXT)
AnnaBridge 182:a56a73fd2a6f 33 /* Timer max counter bit size */
AnnaBridge 182:a56a73fd2a6f 34 #define NU_TMR_MAXCNT_BITSIZE 24
AnnaBridge 182:a56a73fd2a6f 35 /* Timer max counter */
AnnaBridge 182:a56a73fd2a6f 36 #define NU_TMR_MAXCNT ((1 << NU_TMR_MAXCNT_BITSIZE) - 1)
AnnaBridge 172:7d866c31b3c5 37
AnnaBridge 182:a56a73fd2a6f 38 static void tmr1_vec(void);
AnnaBridge 172:7d866c31b3c5 39
AnnaBridge 182:a56a73fd2a6f 40 /* NOTE: To wake the system from power down mode, timer clock source must be ether LXT or LIRC. */
AnnaBridge 182:a56a73fd2a6f 41 static const struct nu_modinit_s timer1_modinit = {TIMER_1, TMR1_MODULE, CLK_CLKSEL1_TMR1SEL_LXT, 0, TMR1_RST, TMR1_IRQn, (void *) tmr1_vec};
AnnaBridge 182:a56a73fd2a6f 42
AnnaBridge 182:a56a73fd2a6f 43 #define TIMER_MODINIT timer1_modinit
AnnaBridge 182:a56a73fd2a6f 44
AnnaBridge 187:0387e8f68319 45 /* Timer interrupt enable/disable
AnnaBridge 187:0387e8f68319 46 *
AnnaBridge 187:0387e8f68319 47 * Because Timer interrupt enable/disable (TIMER_EnableInt/TIMER_DisableInt) needs wait for lp_ticker,
AnnaBridge 187:0387e8f68319 48 * we call NVIC_DisableIRQ/NVIC_EnableIRQ instead.
AnnaBridge 187:0387e8f68319 49 */
AnnaBridge 187:0387e8f68319 50
AnnaBridge 187:0387e8f68319 51 /* Track ticker status */
AnnaBridge 187:0387e8f68319 52 static volatile uint16_t ticker_inited = 0;
AnnaBridge 172:7d866c31b3c5 53
AnnaBridge 172:7d866c31b3c5 54 #define TMR_CMP_MIN 2
AnnaBridge 172:7d866c31b3c5 55 #define TMR_CMP_MAX 0xFFFFFFu
AnnaBridge 172:7d866c31b3c5 56
AnnaBridge 187:0387e8f68319 57 /* Synchronization issue with LXT/LIRC-clocked Timer
AnnaBridge 187:0387e8f68319 58 *
AnnaBridge 187:0387e8f68319 59 * PCLK : typical HCLK/2
AnnaBridge 187:0387e8f68319 60 * ECLK (engine clock) : LXT/LIRC for Timer used to implement lp_ticker
AnnaBridge 187:0387e8f68319 61 *
AnnaBridge 187:0387e8f68319 62 * When system clock is higher than Timer clock (LXT/LIRC), we need to add delay for ECLK
AnnaBridge 187:0387e8f68319 63 * domain to take effect:
AnnaBridge 187:0387e8f68319 64 * 1. Write : typical 1PCLK + 2ECLK
AnnaBridge 187:0387e8f68319 65 * Read-check doesn't work because it just checks PCLK domain and doesn't check into
AnnaBridge 187:0387e8f68319 66 * ECLK domain.
AnnaBridge 187:0387e8f68319 67 * 2. Clear interrupt flag : typical 2PCLK
AnnaBridge 187:0387e8f68319 68 * It is very rare that we would meet dummy interrupt and get stuck in ISR until
AnnaBridge 187:0387e8f68319 69 * 'clear interrupt flag' takes effect. The issue is ignorable because the pending
AnnaBridge 187:0387e8f68319 70 * time is very short (at most 1 dummy interrupt). We won't take special handling for it.
AnnaBridge 187:0387e8f68319 71 */
AnnaBridge 184:08ed48f1de7f 72
AnnaBridge 172:7d866c31b3c5 73 void lp_ticker_init(void)
AnnaBridge 172:7d866c31b3c5 74 {
AnnaBridge 182:a56a73fd2a6f 75 if (ticker_inited) {
AnnaBridge 187:0387e8f68319 76 /* By HAL spec, ticker_init allows the ticker to keep counting and disables the
AnnaBridge 187:0387e8f68319 77 * ticker interrupt. */
AnnaBridge 187:0387e8f68319 78 lp_ticker_disable_interrupt();
AnnaBridge 187:0387e8f68319 79 lp_ticker_clear_interrupt();
AnnaBridge 187:0387e8f68319 80 NVIC_ClearPendingIRQ(TIMER_MODINIT.irq_n);
AnnaBridge 172:7d866c31b3c5 81 return;
AnnaBridge 172:7d866c31b3c5 82 }
AnnaBridge 182:a56a73fd2a6f 83 ticker_inited = 1;
AnnaBridge 172:7d866c31b3c5 84
AnnaBridge 172:7d866c31b3c5 85 // Reset module
AnnaBridge 182:a56a73fd2a6f 86 SYS_ResetModule(TIMER_MODINIT.rsetidx);
AnnaBridge 172:7d866c31b3c5 87
AnnaBridge 172:7d866c31b3c5 88 // Select IP clock source
AnnaBridge 182:a56a73fd2a6f 89 CLK_SetModuleClock(TIMER_MODINIT.clkidx, TIMER_MODINIT.clksrc, TIMER_MODINIT.clkdiv);
AnnaBridge 182:a56a73fd2a6f 90
AnnaBridge 172:7d866c31b3c5 91 // Enable IP clock
AnnaBridge 182:a56a73fd2a6f 92 CLK_EnableModuleClock(TIMER_MODINIT.clkidx);
AnnaBridge 172:7d866c31b3c5 93
AnnaBridge 184:08ed48f1de7f 94 TIMER_T *timer_base = (TIMER_T *) NU_MODBASE(TIMER_MODINIT.modname);
AnnaBridge 184:08ed48f1de7f 95
AnnaBridge 172:7d866c31b3c5 96 // Configure clock
AnnaBridge 184:08ed48f1de7f 97 uint32_t clk_timer = TIMER_GetModuleClock(timer_base);
AnnaBridge 182:a56a73fd2a6f 98 uint32_t prescale_timer = clk_timer / NU_TMRCLK_PER_SEC - 1;
AnnaBridge 182:a56a73fd2a6f 99 MBED_ASSERT((prescale_timer != (uint32_t) -1) && prescale_timer <= 127);
AnnaBridge 182:a56a73fd2a6f 100 MBED_ASSERT((clk_timer % NU_TMRCLK_PER_SEC) == 0);
AnnaBridge 182:a56a73fd2a6f 101 uint32_t cmp_timer = TMR_CMP_MAX;
AnnaBridge 182:a56a73fd2a6f 102 MBED_ASSERT(cmp_timer >= TMR_CMP_MIN && cmp_timer <= TMR_CMP_MAX);
AnnaBridge 172:7d866c31b3c5 103 // Continuous mode
AnnaBridge 172:7d866c31b3c5 104 // NOTE: TIMER_CTL_CNTDATEN_Msk exists in NUC472, but not in M451/M480. In M451/M480, TIMER_CNT is updated continuously by default.
AnnaBridge 184:08ed48f1de7f 105 timer_base->CTL = TIMER_CONTINUOUS_MODE | prescale_timer/* | TIMER_CTL_CNTDATEN_Msk*/;
AnnaBridge 184:08ed48f1de7f 106 wait_us((NU_US_PER_SEC / NU_TMRCLK_PER_SEC) * 3);
AnnaBridge 184:08ed48f1de7f 107
AnnaBridge 184:08ed48f1de7f 108 timer_base->CMP = cmp_timer;
AnnaBridge 184:08ed48f1de7f 109 wait_us((NU_US_PER_SEC / NU_TMRCLK_PER_SEC) * 3);
AnnaBridge 172:7d866c31b3c5 110
AnnaBridge 172:7d866c31b3c5 111 // Set vector
AnnaBridge 182:a56a73fd2a6f 112 NVIC_SetVector(TIMER_MODINIT.irq_n, (uint32_t) TIMER_MODINIT.var);
AnnaBridge 172:7d866c31b3c5 113
AnnaBridge 187:0387e8f68319 114 NVIC_DisableIRQ(TIMER_MODINIT.irq_n);
AnnaBridge 172:7d866c31b3c5 115
AnnaBridge 184:08ed48f1de7f 116 TIMER_EnableInt(timer_base);
AnnaBridge 184:08ed48f1de7f 117 wait_us((NU_US_PER_SEC / NU_TMRCLK_PER_SEC) * 3);
AnnaBridge 184:08ed48f1de7f 118
AnnaBridge 184:08ed48f1de7f 119 TIMER_EnableWakeup(timer_base);
AnnaBridge 182:a56a73fd2a6f 120 wait_us((NU_US_PER_SEC / NU_TMRCLK_PER_SEC) * 3);
AnnaBridge 184:08ed48f1de7f 121
AnnaBridge 184:08ed48f1de7f 122 TIMER_Start(timer_base);
AnnaBridge 184:08ed48f1de7f 123 wait_us((NU_US_PER_SEC / NU_TMRCLK_PER_SEC) * 3);
AnnaBridge 184:08ed48f1de7f 124
AnnaBridge 184:08ed48f1de7f 125 /* Wait for timer to start counting and raise active flag */
AnnaBridge 184:08ed48f1de7f 126 while(! (timer_base->CTL & TIMER_CTL_ACTSTS_Msk));
AnnaBridge 172:7d866c31b3c5 127 }
AnnaBridge 172:7d866c31b3c5 128
AnnaBridge 187:0387e8f68319 129 void lp_ticker_free(void)
AnnaBridge 187:0387e8f68319 130 {
AnnaBridge 187:0387e8f68319 131 TIMER_T *timer_base = (TIMER_T *) NU_MODBASE(TIMER_MODINIT.modname);
AnnaBridge 187:0387e8f68319 132
AnnaBridge 187:0387e8f68319 133 /* Stop counting */
AnnaBridge 187:0387e8f68319 134 TIMER_Stop(timer_base);
AnnaBridge 187:0387e8f68319 135 wait_us((NU_US_PER_SEC / NU_TMRCLK_PER_SEC) * 3);
AnnaBridge 187:0387e8f68319 136
AnnaBridge 187:0387e8f68319 137 /* Wait for timer to stop counting and unset active flag */
AnnaBridge 187:0387e8f68319 138 while((timer_base->CTL & TIMER_CTL_ACTSTS_Msk));
AnnaBridge 187:0387e8f68319 139
AnnaBridge 187:0387e8f68319 140 /* Disable wakeup */
AnnaBridge 187:0387e8f68319 141 TIMER_DisableWakeup(timer_base);
AnnaBridge 187:0387e8f68319 142 wait_us((NU_US_PER_SEC / NU_TMRCLK_PER_SEC) * 3);
AnnaBridge 187:0387e8f68319 143
AnnaBridge 187:0387e8f68319 144 /* Disable interrupt */
AnnaBridge 187:0387e8f68319 145 TIMER_DisableInt(timer_base);
AnnaBridge 187:0387e8f68319 146 wait_us((NU_US_PER_SEC / NU_TMRCLK_PER_SEC) * 3);
AnnaBridge 187:0387e8f68319 147
AnnaBridge 187:0387e8f68319 148 NVIC_DisableIRQ(TIMER_MODINIT.irq_n);
AnnaBridge 187:0387e8f68319 149
AnnaBridge 187:0387e8f68319 150 /* Disable IP clock */
AnnaBridge 187:0387e8f68319 151 CLK_DisableModuleClock(TIMER_MODINIT.clkidx);
AnnaBridge 187:0387e8f68319 152
AnnaBridge 187:0387e8f68319 153 ticker_inited = 0;
AnnaBridge 187:0387e8f68319 154 }
AnnaBridge 187:0387e8f68319 155
AnnaBridge 172:7d866c31b3c5 156 timestamp_t lp_ticker_read()
AnnaBridge 172:7d866c31b3c5 157 {
AnnaBridge 182:a56a73fd2a6f 158 if (! ticker_inited) {
AnnaBridge 172:7d866c31b3c5 159 lp_ticker_init();
AnnaBridge 172:7d866c31b3c5 160 }
AnnaBridge 172:7d866c31b3c5 161
AnnaBridge 184:08ed48f1de7f 162 TIMER_T *timer_base = (TIMER_T *) NU_MODBASE(TIMER_MODINIT.modname);
AnnaBridge 172:7d866c31b3c5 163
AnnaBridge 182:a56a73fd2a6f 164 return (TIMER_GetCounter(timer_base) / NU_TMRCLK_PER_TICK);
AnnaBridge 172:7d866c31b3c5 165 }
AnnaBridge 172:7d866c31b3c5 166
AnnaBridge 172:7d866c31b3c5 167 void lp_ticker_set_interrupt(timestamp_t timestamp)
AnnaBridge 172:7d866c31b3c5 168 {
AnnaBridge 182:a56a73fd2a6f 169 /* In continuous mode, counter will be reset to zero with the following sequence:
AnnaBridge 182:a56a73fd2a6f 170 * 1. Stop counting
AnnaBridge 182:a56a73fd2a6f 171 * 2. Configure new CMP value
AnnaBridge 182:a56a73fd2a6f 172 * 3. Restart counting
AnnaBridge 182:a56a73fd2a6f 173 *
AnnaBridge 182:a56a73fd2a6f 174 * This behavior is not what we want. To fix it, we could configure new CMP value
AnnaBridge 182:a56a73fd2a6f 175 * without stopping counting first.
AnnaBridge 182:a56a73fd2a6f 176 */
AnnaBridge 184:08ed48f1de7f 177 TIMER_T *timer_base = (TIMER_T *) NU_MODBASE(TIMER_MODINIT.modname);
AnnaBridge 172:7d866c31b3c5 178
AnnaBridge 182:a56a73fd2a6f 179 /* NOTE: Because H/W timer requests min compare value, our implementation would have alarm delay of
AnnaBridge 182:a56a73fd2a6f 180 * (TMR_CMP_MIN - interval_clk) clocks when interval_clk is between [1, TMR_CMP_MIN). */
AnnaBridge 182:a56a73fd2a6f 181 uint32_t cmp_timer = timestamp * NU_TMRCLK_PER_TICK;
AnnaBridge 182:a56a73fd2a6f 182 cmp_timer = NU_CLAMP(cmp_timer, TMR_CMP_MIN, TMR_CMP_MAX);
AnnaBridge 184:08ed48f1de7f 183
AnnaBridge 187:0387e8f68319 184 /* NOTE: Rely on LPTICKER_DELAY_TICKS to be non-blocking. */
AnnaBridge 182:a56a73fd2a6f 185 timer_base->CMP = cmp_timer;
AnnaBridge 187:0387e8f68319 186
AnnaBridge 187:0387e8f68319 187 /* We can call ticker_irq_handler now. */
AnnaBridge 187:0387e8f68319 188 NVIC_EnableIRQ(TIMER_MODINIT.irq_n);
AnnaBridge 182:a56a73fd2a6f 189 }
AnnaBridge 182:a56a73fd2a6f 190
AnnaBridge 182:a56a73fd2a6f 191 void lp_ticker_disable_interrupt(void)
AnnaBridge 182:a56a73fd2a6f 192 {
AnnaBridge 187:0387e8f68319 193 /* We cannot call ticker_irq_handler now. */
AnnaBridge 187:0387e8f68319 194 NVIC_DisableIRQ(TIMER_MODINIT.irq_n);
AnnaBridge 182:a56a73fd2a6f 195 }
AnnaBridge 182:a56a73fd2a6f 196
AnnaBridge 182:a56a73fd2a6f 197 void lp_ticker_clear_interrupt(void)
AnnaBridge 182:a56a73fd2a6f 198 {
AnnaBridge 187:0387e8f68319 199 /* To avoid sync issue, we clear TIF/TWKF simultaneously rather than call separate
AnnaBridge 187:0387e8f68319 200 * driver API:
AnnaBridge 187:0387e8f68319 201 *
AnnaBridge 187:0387e8f68319 202 * TIMER_ClearIntFlag((TIMER_T *) NU_MODBASE(TIMER_MODINIT.modname));
AnnaBridge 187:0387e8f68319 203 * TIMER_ClearWakeupFlag((TIMER_T *) NU_MODBASE(TIMER_MODINIT.modname));
AnnaBridge 187:0387e8f68319 204 */
AnnaBridge 187:0387e8f68319 205 TIMER_T *timer_base = (TIMER_T *) NU_MODBASE(TIMER_MODINIT.modname);
AnnaBridge 187:0387e8f68319 206 timer_base->INTSTS = TIMER_INTSTS_TIF_Msk | TIMER_INTSTS_TWKF_Msk;
AnnaBridge 172:7d866c31b3c5 207 }
AnnaBridge 172:7d866c31b3c5 208
AnnaBridge 172:7d866c31b3c5 209 void lp_ticker_fire_interrupt(void)
AnnaBridge 172:7d866c31b3c5 210 {
AnnaBridge 172:7d866c31b3c5 211 // NOTE: This event was in the past. Set the interrupt as pending, but don't process it here.
AnnaBridge 172:7d866c31b3c5 212 // This prevents a recursive loop under heavy load which can lead to a stack overflow.
AnnaBridge 182:a56a73fd2a6f 213 NVIC_SetPendingIRQ(TIMER_MODINIT.irq_n);
AnnaBridge 187:0387e8f68319 214
AnnaBridge 187:0387e8f68319 215 /* We can call ticker_irq_handler now. */
AnnaBridge 187:0387e8f68319 216 NVIC_EnableIRQ(TIMER_MODINIT.irq_n);
AnnaBridge 172:7d866c31b3c5 217 }
AnnaBridge 172:7d866c31b3c5 218
AnnaBridge 182:a56a73fd2a6f 219 const ticker_info_t* lp_ticker_get_info()
AnnaBridge 172:7d866c31b3c5 220 {
AnnaBridge 182:a56a73fd2a6f 221 static const ticker_info_t info = {
AnnaBridge 182:a56a73fd2a6f 222 NU_TMRCLK_PER_SEC / NU_TMRCLK_PER_TICK,
AnnaBridge 182:a56a73fd2a6f 223 NU_TMR_MAXCNT_BITSIZE
AnnaBridge 182:a56a73fd2a6f 224 };
AnnaBridge 182:a56a73fd2a6f 225 return &info;
AnnaBridge 172:7d866c31b3c5 226 }
AnnaBridge 172:7d866c31b3c5 227
AnnaBridge 182:a56a73fd2a6f 228 static void tmr1_vec(void)
AnnaBridge 172:7d866c31b3c5 229 {
AnnaBridge 187:0387e8f68319 230 lp_ticker_clear_interrupt();
AnnaBridge 184:08ed48f1de7f 231
AnnaBridge 182:a56a73fd2a6f 232 // NOTE: lp_ticker_set_interrupt() may get called in lp_ticker_irq_handler();
AnnaBridge 182:a56a73fd2a6f 233 lp_ticker_irq_handler();
AnnaBridge 182:a56a73fd2a6f 234 }
AnnaBridge 172:7d866c31b3c5 235
AnnaBridge 172:7d866c31b3c5 236 #endif