Kev Mann / mbed-dev-OS5_10_4

RTC auf true

hal/LowPowerTickerWrapper.cpp@2:7aab896b1a3b, 2019-03-13 (annotated)

Committer:
kevman
Date:
Wed Mar 13 11:03:24 2019 +0000
Revision:
2:7aab896b1a3b
Parent:
0:38ceb79fef03 
2019-03-13

Who changed what in which revision?

UserRevisionLine numberNew contents of line
kevman 0:38ceb79fef03 1 /* mbed Microcontroller Library
kevman 0:38ceb79fef03 2 * Copyright (c) 2018 ARM Limited
kevman 0:38ceb79fef03 3 *
kevman 0:38ceb79fef03 4 * Licensed under the Apache License, Version 2.0 (the "License");
kevman 0:38ceb79fef03 5 * you may not use this file except in compliance with the License.
kevman 0:38ceb79fef03 6 * You may obtain a copy of the License at
kevman 0:38ceb79fef03 7 *
kevman 0:38ceb79fef03 8 * http://www.apache.org/licenses/LICENSE-2.0
kevman 0:38ceb79fef03 9 *
kevman 0:38ceb79fef03 10 * Unless required by applicable law or agreed to in writing, software
kevman 0:38ceb79fef03 11 * distributed under the License is distributed on an "AS IS" BASIS,
kevman 0:38ceb79fef03 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
kevman 0:38ceb79fef03 13 * See the License for the specific language governing permissions and
kevman 0:38ceb79fef03 14 * limitations under the License.
kevman 0:38ceb79fef03 15 */
kevman 0:38ceb79fef03 16 #include "hal/LowPowerTickerWrapper.h"
kevman 0:38ceb79fef03 17 #include "platform/Callback.h"
kevman 0:38ceb79fef03 18
kevman 0:38ceb79fef03 19 LowPowerTickerWrapper::LowPowerTickerWrapper(const ticker_data_t *data, const ticker_interface_t *interface, uint32_t min_cycles_between_writes, uint32_t min_cycles_until_match)
kevman 0:38ceb79fef03 20 : _intf(data->interface), _min_count_between_writes(min_cycles_between_writes + 1), _min_count_until_match(min_cycles_until_match + 1), _suspended(false)
kevman 0:38ceb79fef03 21 {
kevman 0:38ceb79fef03 22 core_util_critical_section_enter();
kevman 0:38ceb79fef03 23
kevman 0:38ceb79fef03 24 this->data.interface = interface;
kevman 0:38ceb79fef03 25 this->data.queue = data->queue;
kevman 0:38ceb79fef03 26 _reset();
kevman 0:38ceb79fef03 27
kevman 0:38ceb79fef03 28 core_util_critical_section_exit();
kevman 0:38ceb79fef03 29 }
kevman 0:38ceb79fef03 30
kevman 0:38ceb79fef03 31 void LowPowerTickerWrapper::irq_handler(ticker_irq_handler_type handler)
kevman 0:38ceb79fef03 32 {
kevman 0:38ceb79fef03 33 core_util_critical_section_enter();
kevman 0:38ceb79fef03 34
kevman 0:38ceb79fef03 35 if (_pending_fire_now || _match_check(_intf->read()) || _suspended) {
kevman 0:38ceb79fef03 36 _timeout.detach();
kevman 0:38ceb79fef03 37 _pending_timeout = false;
kevman 0:38ceb79fef03 38 _pending_match = false;
kevman 0:38ceb79fef03 39 _pending_fire_now = false;
kevman 0:38ceb79fef03 40 if (handler) {
kevman 0:38ceb79fef03 41 handler(&data);
kevman 0:38ceb79fef03 42 }
kevman 0:38ceb79fef03 43 } else {
kevman 0:38ceb79fef03 44 // Spurious interrupt
kevman 0:38ceb79fef03 45 _intf->clear_interrupt();
kevman 0:38ceb79fef03 46 }
kevman 0:38ceb79fef03 47
kevman 0:38ceb79fef03 48 core_util_critical_section_exit();
kevman 0:38ceb79fef03 49 }
kevman 0:38ceb79fef03 50
kevman 0:38ceb79fef03 51 void LowPowerTickerWrapper::suspend()
kevman 0:38ceb79fef03 52 {
kevman 0:38ceb79fef03 53 core_util_critical_section_enter();
kevman 0:38ceb79fef03 54
kevman 0:38ceb79fef03 55 // Wait until rescheduling is allowed
kevman 0:38ceb79fef03 56 while (!_set_interrupt_allowed) {
kevman 0:38ceb79fef03 57 timestamp_t current = _intf->read();
kevman 0:38ceb79fef03 58 if (((current - _last_actual_set_interrupt) & _mask) >= _min_count_between_writes) {
kevman 0:38ceb79fef03 59 _set_interrupt_allowed = true;
kevman 0:38ceb79fef03 60 }
kevman 0:38ceb79fef03 61 }
kevman 0:38ceb79fef03 62
kevman 0:38ceb79fef03 63 _reset();
kevman 0:38ceb79fef03 64 _suspended = true;
kevman 0:38ceb79fef03 65
kevman 0:38ceb79fef03 66 core_util_critical_section_exit();
kevman 0:38ceb79fef03 67 }
kevman 0:38ceb79fef03 68
kevman 0:38ceb79fef03 69 void LowPowerTickerWrapper::resume()
kevman 0:38ceb79fef03 70 {
kevman 0:38ceb79fef03 71 core_util_critical_section_enter();
kevman 0:38ceb79fef03 72
kevman 0:38ceb79fef03 73 // Wait until rescheduling is allowed
kevman 0:38ceb79fef03 74 while (!_set_interrupt_allowed) {
kevman 0:38ceb79fef03 75 timestamp_t current = _intf->read();
kevman 0:38ceb79fef03 76 if (((current - _last_actual_set_interrupt) & _mask) >= _min_count_between_writes) {
kevman 0:38ceb79fef03 77 _set_interrupt_allowed = true;
kevman 0:38ceb79fef03 78 }
kevman 0:38ceb79fef03 79 }
kevman 0:38ceb79fef03 80
kevman 0:38ceb79fef03 81 _suspended = false;
kevman 0:38ceb79fef03 82
kevman 0:38ceb79fef03 83 core_util_critical_section_exit();
kevman 0:38ceb79fef03 84 }
kevman 0:38ceb79fef03 85
kevman 0:38ceb79fef03 86 bool LowPowerTickerWrapper::timeout_pending()
kevman 0:38ceb79fef03 87 {
kevman 0:38ceb79fef03 88 core_util_critical_section_enter();
kevman 0:38ceb79fef03 89
kevman 0:38ceb79fef03 90 bool pending = _pending_timeout;
kevman 0:38ceb79fef03 91
kevman 0:38ceb79fef03 92 core_util_critical_section_exit();
kevman 0:38ceb79fef03 93 return pending;
kevman 0:38ceb79fef03 94 }
kevman 0:38ceb79fef03 95
kevman 0:38ceb79fef03 96 void LowPowerTickerWrapper::init()
kevman 0:38ceb79fef03 97 {
kevman 0:38ceb79fef03 98 core_util_critical_section_enter();
kevman 0:38ceb79fef03 99
kevman 0:38ceb79fef03 100 _reset();
kevman 0:38ceb79fef03 101 _intf->init();
kevman 0:38ceb79fef03 102
kevman 0:38ceb79fef03 103 core_util_critical_section_exit();
kevman 0:38ceb79fef03 104 }
kevman 0:38ceb79fef03 105
kevman 0:38ceb79fef03 106 void LowPowerTickerWrapper::free()
kevman 0:38ceb79fef03 107 {
kevman 0:38ceb79fef03 108 core_util_critical_section_enter();
kevman 0:38ceb79fef03 109
kevman 0:38ceb79fef03 110 _reset();
kevman 0:38ceb79fef03 111 _intf->free();
kevman 0:38ceb79fef03 112
kevman 0:38ceb79fef03 113 core_util_critical_section_exit();
kevman 0:38ceb79fef03 114 }
kevman 0:38ceb79fef03 115
kevman 0:38ceb79fef03 116 uint32_t LowPowerTickerWrapper::read()
kevman 0:38ceb79fef03 117 {
kevman 0:38ceb79fef03 118 core_util_critical_section_enter();
kevman 0:38ceb79fef03 119
kevman 0:38ceb79fef03 120 timestamp_t current = _intf->read();
kevman 0:38ceb79fef03 121 if (!_suspended && _match_check(current)) {
kevman 0:38ceb79fef03 122 _intf->fire_interrupt();
kevman 0:38ceb79fef03 123 }
kevman 0:38ceb79fef03 124
kevman 0:38ceb79fef03 125 core_util_critical_section_exit();
kevman 0:38ceb79fef03 126 return current;
kevman 0:38ceb79fef03 127 }
kevman 0:38ceb79fef03 128
kevman 0:38ceb79fef03 129 void LowPowerTickerWrapper::set_interrupt(timestamp_t timestamp)
kevman 0:38ceb79fef03 130 {
kevman 0:38ceb79fef03 131 core_util_critical_section_enter();
kevman 0:38ceb79fef03 132
kevman 0:38ceb79fef03 133 _last_set_interrupt = _intf->read();
kevman 0:38ceb79fef03 134 _cur_match_time = timestamp;
kevman 0:38ceb79fef03 135 _pending_match = true;
kevman 0:38ceb79fef03 136 if (!_suspended) {
kevman 0:38ceb79fef03 137 _schedule_match(_last_set_interrupt);
kevman 0:38ceb79fef03 138 } else {
kevman 0:38ceb79fef03 139 _intf->set_interrupt(timestamp);
kevman 0:38ceb79fef03 140 _last_actual_set_interrupt = _last_set_interrupt;
kevman 0:38ceb79fef03 141 _set_interrupt_allowed = false;
kevman 0:38ceb79fef03 142 }
kevman 0:38ceb79fef03 143
kevman 0:38ceb79fef03 144 core_util_critical_section_exit();
kevman 0:38ceb79fef03 145 }
kevman 0:38ceb79fef03 146
kevman 0:38ceb79fef03 147 void LowPowerTickerWrapper::disable_interrupt()
kevman 0:38ceb79fef03 148 {
kevman 0:38ceb79fef03 149 core_util_critical_section_enter();
kevman 0:38ceb79fef03 150
kevman 0:38ceb79fef03 151 _intf->disable_interrupt();
kevman 0:38ceb79fef03 152
kevman 0:38ceb79fef03 153 core_util_critical_section_exit();
kevman 0:38ceb79fef03 154 }
kevman 0:38ceb79fef03 155
kevman 0:38ceb79fef03 156 void LowPowerTickerWrapper::clear_interrupt()
kevman 0:38ceb79fef03 157 {
kevman 0:38ceb79fef03 158 core_util_critical_section_enter();
kevman 0:38ceb79fef03 159
kevman 0:38ceb79fef03 160 _intf->clear_interrupt();
kevman 0:38ceb79fef03 161
kevman 0:38ceb79fef03 162 core_util_critical_section_exit();
kevman 0:38ceb79fef03 163 }
kevman 0:38ceb79fef03 164
kevman 0:38ceb79fef03 165 void LowPowerTickerWrapper::fire_interrupt()
kevman 0:38ceb79fef03 166 {
kevman 0:38ceb79fef03 167 core_util_critical_section_enter();
kevman 0:38ceb79fef03 168
kevman 0:38ceb79fef03 169 _pending_fire_now = 1;
kevman 0:38ceb79fef03 170 _intf->fire_interrupt();
kevman 0:38ceb79fef03 171
kevman 0:38ceb79fef03 172 core_util_critical_section_exit();
kevman 0:38ceb79fef03 173 }
kevman 0:38ceb79fef03 174
kevman 0:38ceb79fef03 175 const ticker_info_t *LowPowerTickerWrapper::get_info()
kevman 0:38ceb79fef03 176 {
kevman 0:38ceb79fef03 177
kevman 0:38ceb79fef03 178 core_util_critical_section_enter();
kevman 0:38ceb79fef03 179
kevman 0:38ceb79fef03 180 const ticker_info_t *info = _intf->get_info();
kevman 0:38ceb79fef03 181
kevman 0:38ceb79fef03 182 core_util_critical_section_exit();
kevman 0:38ceb79fef03 183 return info;
kevman 0:38ceb79fef03 184 }
kevman 0:38ceb79fef03 185
kevman 0:38ceb79fef03 186 void LowPowerTickerWrapper::_reset()
kevman 0:38ceb79fef03 187 {
kevman 0:38ceb79fef03 188 MBED_ASSERT(core_util_in_critical_section());
kevman 0:38ceb79fef03 189
kevman 0:38ceb79fef03 190 _timeout.detach();
kevman 0:38ceb79fef03 191 _pending_timeout = false;
kevman 0:38ceb79fef03 192 _pending_match = false;
kevman 0:38ceb79fef03 193 _pending_fire_now = false;
kevman 0:38ceb79fef03 194 _set_interrupt_allowed = true;
kevman 0:38ceb79fef03 195 _cur_match_time = 0;
kevman 0:38ceb79fef03 196 _last_set_interrupt = 0;
kevman 0:38ceb79fef03 197 _last_actual_set_interrupt = 0;
kevman 0:38ceb79fef03 198
kevman 0:38ceb79fef03 199 const ticker_info_t *info = _intf->get_info();
kevman 0:38ceb79fef03 200 if (info->bits >= 32) {
kevman 0:38ceb79fef03 201 _mask = 0xffffffff;
kevman 0:38ceb79fef03 202 } else {
kevman 0:38ceb79fef03 203 _mask = ((uint64_t)1 << info->bits) - 1;
kevman 0:38ceb79fef03 204 }
kevman 0:38ceb79fef03 205
kevman 0:38ceb79fef03 206 // Round us_per_tick up
kevman 0:38ceb79fef03 207 _us_per_tick = (1000000 + info->frequency - 1) / info->frequency;
kevman 0:38ceb79fef03 208 }
kevman 0:38ceb79fef03 209
kevman 0:38ceb79fef03 210 void LowPowerTickerWrapper::_timeout_handler()
kevman 0:38ceb79fef03 211 {
kevman 0:38ceb79fef03 212 core_util_critical_section_enter();
kevman 0:38ceb79fef03 213 _pending_timeout = false;
kevman 0:38ceb79fef03 214
kevman 0:38ceb79fef03 215 timestamp_t current = _intf->read();
kevman 0:38ceb79fef03 216 /* Add extra check for '_last_set_interrupt == _cur_match_time'
kevman 0:38ceb79fef03 217 *
kevman 0:38ceb79fef03 218 * When '_last_set_interrupt == _cur_match_time', _ticker_match_interval_passed sees it as
kevman 0:38ceb79fef03 219 * one-round interval rather than just-pass, so add extra check for it. In rare cases, we
kevman 0:38ceb79fef03 220 * may trap in _timeout_handler/_schedule_match loop. This check can break it.
kevman 0:38ceb79fef03 221 */
kevman 0:38ceb79fef03 222 if ((_last_set_interrupt == _cur_match_time) ||
kevman 0:38ceb79fef03 223 _ticker_match_interval_passed(_last_set_interrupt, current, _cur_match_time)) {
kevman 0:38ceb79fef03 224 _intf->fire_interrupt();
kevman 0:38ceb79fef03 225 } else {
kevman 0:38ceb79fef03 226 _schedule_match(current);
kevman 0:38ceb79fef03 227 }
kevman 0:38ceb79fef03 228
kevman 0:38ceb79fef03 229 core_util_critical_section_exit();
kevman 0:38ceb79fef03 230 }
kevman 0:38ceb79fef03 231
kevman 0:38ceb79fef03 232 bool LowPowerTickerWrapper::_match_check(timestamp_t current)
kevman 0:38ceb79fef03 233 {
kevman 0:38ceb79fef03 234 MBED_ASSERT(core_util_in_critical_section());
kevman 0:38ceb79fef03 235
kevman 0:38ceb79fef03 236 if (!_pending_match) {
kevman 0:38ceb79fef03 237 return false;
kevman 0:38ceb79fef03 238 }
kevman 0:38ceb79fef03 239 /* Add extra check for '_last_set_interrupt == _cur_match_time' as above */
kevman 0:38ceb79fef03 240 return (_last_set_interrupt == _cur_match_time) ||
kevman 0:38ceb79fef03 241 _ticker_match_interval_passed(_last_set_interrupt, current, _cur_match_time);
kevman 0:38ceb79fef03 242 }
kevman 0:38ceb79fef03 243
kevman 0:38ceb79fef03 244 uint32_t LowPowerTickerWrapper::_lp_ticks_to_us(uint32_t ticks)
kevman 0:38ceb79fef03 245 {
kevman 0:38ceb79fef03 246 MBED_ASSERT(core_util_in_critical_section());
kevman 0:38ceb79fef03 247
kevman 0:38ceb79fef03 248 // Add 4 microseconds to round up the micro second ticker time (which has a frequency of at least 250KHz - 4us period)
kevman 0:38ceb79fef03 249 return _us_per_tick * ticks + 4;
kevman 0:38ceb79fef03 250 }
kevman 0:38ceb79fef03 251
kevman 0:38ceb79fef03 252 void LowPowerTickerWrapper::_schedule_match(timestamp_t current)
kevman 0:38ceb79fef03 253 {
kevman 0:38ceb79fef03 254 MBED_ASSERT(core_util_in_critical_section());
kevman 0:38ceb79fef03 255
kevman 0:38ceb79fef03 256 // Check if _intf->set_interrupt is allowed
kevman 0:38ceb79fef03 257 if (!_set_interrupt_allowed) {
kevman 0:38ceb79fef03 258 if (((current - _last_actual_set_interrupt) & _mask) >= _min_count_between_writes) {
kevman 0:38ceb79fef03 259 _set_interrupt_allowed = true;
kevman 0:38ceb79fef03 260 }
kevman 0:38ceb79fef03 261 }
kevman 0:38ceb79fef03 262
kevman 0:38ceb79fef03 263 uint32_t cycles_until_match = (_cur_match_time - current) & _mask;
kevman 0:38ceb79fef03 264 bool too_close = cycles_until_match < _min_count_until_match;
kevman 0:38ceb79fef03 265
kevman 0:38ceb79fef03 266 if (!_set_interrupt_allowed) {
kevman 0:38ceb79fef03 267
kevman 0:38ceb79fef03 268 // Can't use _intf->set_interrupt so use microsecond Timeout instead
kevman 0:38ceb79fef03 269
kevman 0:38ceb79fef03 270 // Speed optimization - if a timer has already been scheduled
kevman 0:38ceb79fef03 271 // then don't schedule it again.
kevman 0:38ceb79fef03 272 if (!_pending_timeout) {
kevman 0:38ceb79fef03 273 uint32_t ticks = cycles_until_match < _min_count_until_match ? cycles_until_match : _min_count_until_match;
kevman 0:38ceb79fef03 274 _timeout.attach_us(mbed::callback(this, &LowPowerTickerWrapper::_timeout_handler), _lp_ticks_to_us(ticks));
kevman 0:38ceb79fef03 275 _pending_timeout = true;
kevman 0:38ceb79fef03 276 }
kevman 0:38ceb79fef03 277 return;
kevman 0:38ceb79fef03 278 }
kevman 0:38ceb79fef03 279
kevman 0:38ceb79fef03 280 if (!too_close) {
kevman 0:38ceb79fef03 281
kevman 0:38ceb79fef03 282 // Schedule LP ticker
kevman 0:38ceb79fef03 283 _intf->set_interrupt(_cur_match_time);
kevman 0:38ceb79fef03 284 current = _intf->read();
kevman 0:38ceb79fef03 285 _last_actual_set_interrupt = current;
kevman 0:38ceb79fef03 286 _set_interrupt_allowed = false;
kevman 0:38ceb79fef03 287
kevman 0:38ceb79fef03 288 // Check for overflow
kevman 0:38ceb79fef03 289 uint32_t new_cycles_until_match = (_cur_match_time - current) & _mask;
kevman 0:38ceb79fef03 290 if (new_cycles_until_match > cycles_until_match) {
kevman 0:38ceb79fef03 291 // Overflow so fire now
kevman 0:38ceb79fef03 292 _intf->fire_interrupt();
kevman 0:38ceb79fef03 293 return;
kevman 0:38ceb79fef03 294 }
kevman 0:38ceb79fef03 295
kevman 0:38ceb79fef03 296 // Update variables with new time
kevman 0:38ceb79fef03 297 cycles_until_match = new_cycles_until_match;
kevman 0:38ceb79fef03 298 too_close = cycles_until_match < _min_count_until_match;
kevman 0:38ceb79fef03 299 }
kevman 0:38ceb79fef03 300
kevman 0:38ceb79fef03 301 if (too_close) {
kevman 0:38ceb79fef03 302
kevman 0:38ceb79fef03 303 // Low power ticker incremented to less than _min_count_until_match
kevman 0:38ceb79fef03 304 // so low power ticker may not fire. Use Timeout to ensure it does fire.
kevman 0:38ceb79fef03 305 uint32_t ticks = cycles_until_match < _min_count_until_match ? cycles_until_match : _min_count_until_match;
kevman 0:38ceb79fef03 306 _timeout.attach_us(mbed::callback(this, &LowPowerTickerWrapper::_timeout_handler), _lp_ticks_to_us(ticks));
kevman 0:38ceb79fef03 307 _pending_timeout = true;
kevman 0:38ceb79fef03 308 return;
kevman 0:38ceb79fef03 309 }
kevman 0:38ceb79fef03 310 }