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_NANO100/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 174:b96e65c34a4d 1 /* mbed Microcontroller Library
AnnaBridge 174:b96e65c34a4d 2 * Copyright (c) 2015-2017 Nuvoton
AnnaBridge 174:b96e65c34a4d 3 *
AnnaBridge 174:b96e65c34a4d 4 * Licensed under the Apache License, Version 2.0 (the "License");
AnnaBridge 174:b96e65c34a4d 5 * you may not use this file except in compliance with the License.
AnnaBridge 174:b96e65c34a4d 6 * You may obtain a copy of the License at
AnnaBridge 174:b96e65c34a4d 7 *
AnnaBridge 174:b96e65c34a4d 8 * http://www.apache.org/licenses/LICENSE-2.0
AnnaBridge 174:b96e65c34a4d 9 *
AnnaBridge 174:b96e65c34a4d 10 * Unless required by applicable law or agreed to in writing, software
AnnaBridge 174:b96e65c34a4d 11 * distributed under the License is distributed on an "AS IS" BASIS,
AnnaBridge 174:b96e65c34a4d 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
AnnaBridge 174:b96e65c34a4d 13 * See the License for the specific language governing permissions and
AnnaBridge 174:b96e65c34a4d 14 * limitations under the License.
AnnaBridge 174:b96e65c34a4d 15 */
AnnaBridge 182:a56a73fd2a6f 16
AnnaBridge 174:b96e65c34a4d 17 #include "lp_ticker_api.h"
AnnaBridge 174:b96e65c34a4d 18
Anna Bridge 186:707f6e361f3e 19 #if DEVICE_LPTICKER
AnnaBridge 174:b96e65c34a4d 20
AnnaBridge 174:b96e65c34a4d 21 #include "sleep_api.h"
AnnaBridge 182:a56a73fd2a6f 22 #include "mbed_wait_api.h"
AnnaBridge 182:a56a73fd2a6f 23 #include "mbed_assert.h"
AnnaBridge 174:b96e65c34a4d 24 #include "nu_modutil.h"
AnnaBridge 174:b96e65c34a4d 25 #include "nu_miscutil.h"
AnnaBridge 174:b96e65c34a4d 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 174:b96e65c34a4d 37
AnnaBridge 182:a56a73fd2a6f 38 /* NOTE: Don't add static modifier here. These IRQ handler symbols are for linking.
AnnaBridge 182:a56a73fd2a6f 39 Vector table relocation is not actually supported for low-resource target. */
AnnaBridge 182:a56a73fd2a6f 40 void TMR1_IRQHandler(void);
AnnaBridge 174:b96e65c34a4d 41
AnnaBridge 182:a56a73fd2a6f 42 /* NOTE: To wake the system from power down mode, timer clock source must be ether LXT or LIRC. */
AnnaBridge 182:a56a73fd2a6f 43 static const struct nu_modinit_s timer1_modinit = {TIMER_1, TMR1_MODULE, CLK_CLKSEL1_TMR1_S_LXT, 0, TMR1_RST, TMR1_IRQn, (void *) TMR1_IRQHandler};
AnnaBridge 182:a56a73fd2a6f 44
AnnaBridge 182:a56a73fd2a6f 45 #define TIMER_MODINIT timer1_modinit
AnnaBridge 182:a56a73fd2a6f 46
AnnaBridge 187:0387e8f68319 47 /* Timer interrupt enable/disable
AnnaBridge 187:0387e8f68319 48 *
AnnaBridge 187:0387e8f68319 49 * Because Timer interrupt enable/disable (TIMER_EnableInt/TIMER_DisableInt) needs wait for lp_ticker,
AnnaBridge 187:0387e8f68319 50 * we call NVIC_DisableIRQ/NVIC_EnableIRQ instead.
AnnaBridge 187:0387e8f68319 51 */
AnnaBridge 187:0387e8f68319 52
AnnaBridge 187:0387e8f68319 53 /* Track ticker status */
AnnaBridge 187:0387e8f68319 54 static volatile uint16_t ticker_inited = 0;
AnnaBridge 174:b96e65c34a4d 55
AnnaBridge 174:b96e65c34a4d 56 #define TMR_CMP_MIN 2
AnnaBridge 174:b96e65c34a4d 57 #define TMR_CMP_MAX 0xFFFFFFu
AnnaBridge 174:b96e65c34a4d 58
AnnaBridge 187:0387e8f68319 59 /* Synchronization issue with LXT/LIRC-clocked Timer
AnnaBridge 187:0387e8f68319 60 *
AnnaBridge 187:0387e8f68319 61 * PCLK : typical HCLK/2
AnnaBridge 187:0387e8f68319 62 * ECLK (engine clock) : LXT/LIRC for Timer used to implement lp_ticker
AnnaBridge 187:0387e8f68319 63 *
AnnaBridge 187:0387e8f68319 64 * When system clock is higher than Timer clock (LXT/LIRC), we need to add delay for ECLK
AnnaBridge 187:0387e8f68319 65 * domain to take effect:
AnnaBridge 187:0387e8f68319 66 * 1. Write : typical 1PCLK + 2ECLK
AnnaBridge 187:0387e8f68319 67 * Read-check doesn't work because it just checks PCLK domain and doesn't check into
AnnaBridge 187:0387e8f68319 68 * ECLK domain.
AnnaBridge 187:0387e8f68319 69 * 2. Clear interrupt flag : typical 2PCLK
AnnaBridge 187:0387e8f68319 70 * It is very rare that we would meet dummy interrupt and get stuck in ISR until
AnnaBridge 187:0387e8f68319 71 * 'clear interrupt flag' takes effect. The issue is ignorable because the pending
AnnaBridge 187:0387e8f68319 72 * time is very short (at most 1 dummy interrupt). We won't take special handling for it.
AnnaBridge 187:0387e8f68319 73 */
AnnaBridge 184:08ed48f1de7f 74
AnnaBridge 174:b96e65c34a4d 75 void lp_ticker_init(void)
AnnaBridge 174:b96e65c34a4d 76 {
AnnaBridge 182:a56a73fd2a6f 77 if (ticker_inited) {
AnnaBridge 187:0387e8f68319 78 /* By HAL spec, ticker_init allows the ticker to keep counting and disables the
AnnaBridge 187:0387e8f68319 79 * ticker interrupt. */
AnnaBridge 187:0387e8f68319 80 lp_ticker_disable_interrupt();
AnnaBridge 187:0387e8f68319 81 lp_ticker_clear_interrupt();
AnnaBridge 187:0387e8f68319 82 NVIC_ClearPendingIRQ(TIMER_MODINIT.irq_n);
AnnaBridge 174:b96e65c34a4d 83 return;
AnnaBridge 174:b96e65c34a4d 84 }
AnnaBridge 182:a56a73fd2a6f 85 ticker_inited = 1;
AnnaBridge 174:b96e65c34a4d 86
AnnaBridge 174:b96e65c34a4d 87 // Reset module
AnnaBridge 182:a56a73fd2a6f 88 SYS_ResetModule(TIMER_MODINIT.rsetidx);
AnnaBridge 182:a56a73fd2a6f 89
AnnaBridge 174:b96e65c34a4d 90 // Select IP clock source
AnnaBridge 182:a56a73fd2a6f 91 CLK_SetModuleClock(TIMER_MODINIT.clkidx, TIMER_MODINIT.clksrc, TIMER_MODINIT.clkdiv);
AnnaBridge 182:a56a73fd2a6f 92
AnnaBridge 174:b96e65c34a4d 93 // Enable IP clock
AnnaBridge 182:a56a73fd2a6f 94 CLK_EnableModuleClock(TIMER_MODINIT.clkidx);
AnnaBridge 174:b96e65c34a4d 95
AnnaBridge 184:08ed48f1de7f 96 TIMER_T *timer_base = (TIMER_T *) NU_MODBASE(TIMER_MODINIT.modname);
AnnaBridge 184:08ed48f1de7f 97
AnnaBridge 174:b96e65c34a4d 98 // Configure clock
AnnaBridge 184:08ed48f1de7f 99 uint32_t clk_timer = TIMER_GetModuleClock(timer_base);
AnnaBridge 182:a56a73fd2a6f 100 uint32_t prescale_timer = clk_timer / NU_TMRCLK_PER_SEC - 1;
AnnaBridge 182:a56a73fd2a6f 101 MBED_ASSERT((prescale_timer != (uint32_t) -1) && prescale_timer <= 127);
AnnaBridge 182:a56a73fd2a6f 102 MBED_ASSERT((clk_timer % NU_TMRCLK_PER_SEC) == 0);
AnnaBridge 182:a56a73fd2a6f 103 uint32_t cmp_timer = TMR_CMP_MAX;
AnnaBridge 182:a56a73fd2a6f 104 MBED_ASSERT(cmp_timer >= TMR_CMP_MIN && cmp_timer <= TMR_CMP_MAX);
AnnaBridge 174:b96e65c34a4d 105 // Continuous mode
AnnaBridge 184:08ed48f1de7f 106 timer_base->CTL = TIMER_CONTINUOUS_MODE;
AnnaBridge 184:08ed48f1de7f 107 wait_us((NU_US_PER_SEC / NU_TMRCLK_PER_SEC) * 3);
AnnaBridge 184:08ed48f1de7f 108
AnnaBridge 184:08ed48f1de7f 109 timer_base->PRECNT = prescale_timer;
AnnaBridge 184:08ed48f1de7f 110 wait_us((NU_US_PER_SEC / NU_TMRCLK_PER_SEC) * 3);
AnnaBridge 184:08ed48f1de7f 111
AnnaBridge 184:08ed48f1de7f 112 timer_base->CMPR = cmp_timer;
AnnaBridge 184:08ed48f1de7f 113 wait_us((NU_US_PER_SEC / NU_TMRCLK_PER_SEC) * 3);
AnnaBridge 182:a56a73fd2a6f 114
AnnaBridge 174:b96e65c34a4d 115 // Set vector
AnnaBridge 182:a56a73fd2a6f 116 NVIC_SetVector(TIMER_MODINIT.irq_n, (uint32_t) TIMER_MODINIT.var);
AnnaBridge 182:a56a73fd2a6f 117
AnnaBridge 187:0387e8f68319 118 NVIC_DisableIRQ(TIMER_MODINIT.irq_n);
AnnaBridge 174:b96e65c34a4d 119
AnnaBridge 184:08ed48f1de7f 120 TIMER_EnableInt(timer_base);
AnnaBridge 184:08ed48f1de7f 121 wait_us((NU_US_PER_SEC / NU_TMRCLK_PER_SEC) * 3);
AnnaBridge 184:08ed48f1de7f 122
AnnaBridge 184:08ed48f1de7f 123 TIMER_EnableWakeup(timer_base);
AnnaBridge 182:a56a73fd2a6f 124 wait_us((NU_US_PER_SEC / NU_TMRCLK_PER_SEC) * 3);
AnnaBridge 184:08ed48f1de7f 125
AnnaBridge 184:08ed48f1de7f 126 TIMER_Start(timer_base);
AnnaBridge 184:08ed48f1de7f 127 wait_us((NU_US_PER_SEC / NU_TMRCLK_PER_SEC) * 3);
AnnaBridge 184:08ed48f1de7f 128
AnnaBridge 184:08ed48f1de7f 129 /* Wait for timer to start counting and raise active flag */
AnnaBridge 184:08ed48f1de7f 130 while(! (timer_base->CTL & TIMER_CTL_TMR_ACT_Msk));
AnnaBridge 174:b96e65c34a4d 131 }
AnnaBridge 174:b96e65c34a4d 132
AnnaBridge 187:0387e8f68319 133 void lp_ticker_free(void)
AnnaBridge 187:0387e8f68319 134 {
AnnaBridge 187:0387e8f68319 135 TIMER_T *timer_base = (TIMER_T *) NU_MODBASE(TIMER_MODINIT.modname);
AnnaBridge 187:0387e8f68319 136
AnnaBridge 187:0387e8f68319 137 /* Stop counting */
AnnaBridge 187:0387e8f68319 138 TIMER_Stop(timer_base);
AnnaBridge 187:0387e8f68319 139 wait_us((NU_US_PER_SEC / NU_TMRCLK_PER_SEC) * 3);
AnnaBridge 187:0387e8f68319 140
AnnaBridge 187:0387e8f68319 141 /* Wait for timer to stop counting and unset active flag */
AnnaBridge 187:0387e8f68319 142 while((timer_base->CTL & TIMER_CTL_TMR_ACT_Msk));
AnnaBridge 187:0387e8f68319 143
AnnaBridge 187:0387e8f68319 144 /* Disable wakeup */
AnnaBridge 187:0387e8f68319 145 TIMER_DisableWakeup(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 /* Disable interrupt */
AnnaBridge 187:0387e8f68319 149 TIMER_DisableInt(timer_base);
AnnaBridge 187:0387e8f68319 150 wait_us((NU_US_PER_SEC / NU_TMRCLK_PER_SEC) * 3);
AnnaBridge 187:0387e8f68319 151
AnnaBridge 187:0387e8f68319 152 NVIC_DisableIRQ(TIMER_MODINIT.irq_n);
AnnaBridge 187:0387e8f68319 153
AnnaBridge 187:0387e8f68319 154 /* Disable IP clock */
AnnaBridge 187:0387e8f68319 155 CLK_DisableModuleClock(TIMER_MODINIT.clkidx);
AnnaBridge 187:0387e8f68319 156
AnnaBridge 187:0387e8f68319 157 ticker_inited = 0;
AnnaBridge 187:0387e8f68319 158 }
AnnaBridge 187:0387e8f68319 159
AnnaBridge 174:b96e65c34a4d 160 timestamp_t lp_ticker_read()
AnnaBridge 182:a56a73fd2a6f 161 {
AnnaBridge 182:a56a73fd2a6f 162 if (! ticker_inited) {
AnnaBridge 174:b96e65c34a4d 163 lp_ticker_init();
AnnaBridge 174:b96e65c34a4d 164 }
AnnaBridge 174:b96e65c34a4d 165
AnnaBridge 184:08ed48f1de7f 166 TIMER_T *timer_base = (TIMER_T *) NU_MODBASE(TIMER_MODINIT.modname);
AnnaBridge 182:a56a73fd2a6f 167
AnnaBridge 182:a56a73fd2a6f 168 return (TIMER_GetCounter(timer_base) / NU_TMRCLK_PER_TICK);
AnnaBridge 174:b96e65c34a4d 169 }
AnnaBridge 174:b96e65c34a4d 170
AnnaBridge 174:b96e65c34a4d 171 void lp_ticker_set_interrupt(timestamp_t timestamp)
AnnaBridge 174:b96e65c34a4d 172 {
AnnaBridge 182:a56a73fd2a6f 173 /* In continuous mode, counter will be reset to zero with the following sequence:
AnnaBridge 182:a56a73fd2a6f 174 * 1. Stop counting
AnnaBridge 182:a56a73fd2a6f 175 * 2. Configure new CMP value
AnnaBridge 182:a56a73fd2a6f 176 * 3. Restart counting
AnnaBridge 182:a56a73fd2a6f 177 *
AnnaBridge 182:a56a73fd2a6f 178 * This behavior is not what we want. To fix it, we could configure new CMP value
AnnaBridge 182:a56a73fd2a6f 179 * without stopping counting first.
AnnaBridge 182:a56a73fd2a6f 180 */
AnnaBridge 184:08ed48f1de7f 181 TIMER_T *timer_base = (TIMER_T *) NU_MODBASE(TIMER_MODINIT.modname);
AnnaBridge 174:b96e65c34a4d 182
AnnaBridge 182:a56a73fd2a6f 183 /* NOTE: Because H/W timer requests min compare value, our implementation would have alarm delay of
AnnaBridge 182:a56a73fd2a6f 184 * (TMR_CMP_MIN - interval_clk) clocks when interval_clk is between [1, TMR_CMP_MIN). */
AnnaBridge 182:a56a73fd2a6f 185 uint32_t cmp_timer = timestamp * NU_TMRCLK_PER_TICK;
AnnaBridge 182:a56a73fd2a6f 186 cmp_timer = NU_CLAMP(cmp_timer, TMR_CMP_MIN, TMR_CMP_MAX);
AnnaBridge 184:08ed48f1de7f 187
AnnaBridge 187:0387e8f68319 188 /* NOTE: Rely on LPTICKER_DELAY_TICKS to be non-blocking. */
AnnaBridge 182:a56a73fd2a6f 189 timer_base->CMPR = cmp_timer;
AnnaBridge 187:0387e8f68319 190
AnnaBridge 187:0387e8f68319 191 /* We can call ticker_irq_handler now. */
AnnaBridge 187:0387e8f68319 192 NVIC_EnableIRQ(TIMER_MODINIT.irq_n);
AnnaBridge 174:b96e65c34a4d 193 }
AnnaBridge 174:b96e65c34a4d 194
AnnaBridge 174:b96e65c34a4d 195 void lp_ticker_disable_interrupt(void)
AnnaBridge 174:b96e65c34a4d 196 {
AnnaBridge 187:0387e8f68319 197 /* We cannot call ticker_irq_handler now. */
AnnaBridge 187:0387e8f68319 198 NVIC_DisableIRQ(TIMER_MODINIT.irq_n);
AnnaBridge 174:b96e65c34a4d 199 }
AnnaBridge 174:b96e65c34a4d 200
AnnaBridge 174:b96e65c34a4d 201 void lp_ticker_clear_interrupt(void)
AnnaBridge 174:b96e65c34a4d 202 {
AnnaBridge 187:0387e8f68319 203 /* To avoid sync issue, we clear TIF/TWKF simultaneously rather than call separate
AnnaBridge 187:0387e8f68319 204 * driver API:
AnnaBridge 187:0387e8f68319 205 *
AnnaBridge 187:0387e8f68319 206 * TIMER_ClearIntFlag((TIMER_T *) NU_MODBASE(TIMER_MODINIT.modname));
AnnaBridge 187:0387e8f68319 207 * TIMER_ClearWakeupFlag((TIMER_T *) NU_MODBASE(TIMER_MODINIT.modname));
AnnaBridge 187:0387e8f68319 208 */
AnnaBridge 187:0387e8f68319 209 TIMER_T *timer_base = (TIMER_T *) NU_MODBASE(TIMER_MODINIT.modname);
AnnaBridge 187:0387e8f68319 210 timer_base->ISR = TIMER_ISR_TMR_IS_Msk | TIMER_ISR_TMR_WAKE_STS_Msk;
AnnaBridge 174:b96e65c34a4d 211 }
AnnaBridge 174:b96e65c34a4d 212
AnnaBridge 182:a56a73fd2a6f 213 void lp_ticker_fire_interrupt(void)
AnnaBridge 174:b96e65c34a4d 214 {
AnnaBridge 182:a56a73fd2a6f 215 // NOTE: This event was in the past. Set the interrupt as pending, but don't process it here.
AnnaBridge 182:a56a73fd2a6f 216 // This prevents a recursive loop under heavy load which can lead to a stack overflow.
AnnaBridge 182:a56a73fd2a6f 217 NVIC_SetPendingIRQ(TIMER_MODINIT.irq_n);
AnnaBridge 187:0387e8f68319 218
AnnaBridge 187:0387e8f68319 219 /* We can call ticker_irq_handler now. */
AnnaBridge 187:0387e8f68319 220 NVIC_EnableIRQ(TIMER_MODINIT.irq_n);
AnnaBridge 174:b96e65c34a4d 221 }
AnnaBridge 174:b96e65c34a4d 222
AnnaBridge 182:a56a73fd2a6f 223 const ticker_info_t* lp_ticker_get_info()
AnnaBridge 174:b96e65c34a4d 224 {
AnnaBridge 182:a56a73fd2a6f 225 static const ticker_info_t info = {
AnnaBridge 182:a56a73fd2a6f 226 NU_TMRCLK_PER_SEC / NU_TMRCLK_PER_TICK,
AnnaBridge 182:a56a73fd2a6f 227 NU_TMR_MAXCNT_BITSIZE
AnnaBridge 182:a56a73fd2a6f 228 };
AnnaBridge 182:a56a73fd2a6f 229 return &info;
AnnaBridge 182:a56a73fd2a6f 230 }
AnnaBridge 182:a56a73fd2a6f 231
AnnaBridge 182:a56a73fd2a6f 232 void TMR1_IRQHandler(void)
AnnaBridge 182:a56a73fd2a6f 233 {
AnnaBridge 187:0387e8f68319 234 lp_ticker_clear_interrupt();
AnnaBridge 184:08ed48f1de7f 235
AnnaBridge 182:a56a73fd2a6f 236 // NOTE: lp_ticker_set_interrupt() may get called in lp_ticker_irq_handler();
AnnaBridge 182:a56a73fd2a6f 237 lp_ticker_irq_handler();
AnnaBridge 174:b96e65c34a4d 238 }
AnnaBridge 182:a56a73fd2a6f 239
AnnaBridge 174:b96e65c34a4d 240 #endif