qemu/hw/timer/stm32f2xx_timer.c
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   1/*
   2 * STM32F2XX Timer
   3 *
   4 * Copyright (c) 2014 Alistair Francis <alistair@alistair23.me>
   5 *
   6 * Permission is hereby granted, free of charge, to any person obtaining a copy
   7 * of this software and associated documentation files (the "Software"), to deal
   8 * in the Software without restriction, including without limitation the rights
   9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10 * copies of the Software, and to permit persons to whom the Software is
  11 * furnished to do so, subject to the following conditions:
  12 *
  13 * The above copyright notice and this permission notice shall be included in
  14 * all copies or substantial portions of the Software.
  15 *
  16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22 * THE SOFTWARE.
  23 */
  24
  25#include "qemu/osdep.h"
  26#include "hw/timer/stm32f2xx_timer.h"
  27#include "qemu/log.h"
  28
  29#ifndef STM_TIMER_ERR_DEBUG
  30#define STM_TIMER_ERR_DEBUG 0
  31#endif
  32
  33#define DB_PRINT_L(lvl, fmt, args...) do { \
  34    if (STM_TIMER_ERR_DEBUG >= lvl) { \
  35        qemu_log("%s: " fmt, __func__, ## args); \
  36    } \
  37} while (0)
  38
  39#define DB_PRINT(fmt, args...) DB_PRINT_L(1, fmt, ## args)
  40
  41static void stm32f2xx_timer_set_alarm(STM32F2XXTimerState *s, int64_t now);
  42
  43static void stm32f2xx_timer_interrupt(void *opaque)
  44{
  45    STM32F2XXTimerState *s = opaque;
  46
  47    DB_PRINT("Interrupt\n");
  48
  49    if (s->tim_dier & TIM_DIER_UIE && s->tim_cr1 & TIM_CR1_CEN) {
  50        s->tim_sr |= 1;
  51        qemu_irq_pulse(s->irq);
  52        stm32f2xx_timer_set_alarm(s, s->hit_time);
  53    }
  54
  55    if (s->tim_ccmr1 & (TIM_CCMR1_OC2M2 | TIM_CCMR1_OC2M1) &&
  56        !(s->tim_ccmr1 & TIM_CCMR1_OC2M0) &&
  57        s->tim_ccmr1 & TIM_CCMR1_OC2PE &&
  58        s->tim_ccer & TIM_CCER_CC2E) {
  59        /* PWM 2 - Mode 1 */
  60        DB_PRINT("PWM2 Duty Cycle: %d%%\n",
  61                s->tim_ccr2 / (100 * (s->tim_psc + 1)));
  62    }
  63}
  64
  65static inline int64_t stm32f2xx_ns_to_ticks(STM32F2XXTimerState *s, int64_t t)
  66{
  67    return muldiv64(t, s->freq_hz, 1000000000ULL) / (s->tim_psc + 1);
  68}
  69
  70static void stm32f2xx_timer_set_alarm(STM32F2XXTimerState *s, int64_t now)
  71{
  72    uint64_t ticks;
  73    int64_t now_ticks;
  74
  75    if (s->tim_arr == 0) {
  76        return;
  77    }
  78
  79    DB_PRINT("Alarm set at: 0x%x\n", s->tim_cr1);
  80
  81    now_ticks = stm32f2xx_ns_to_ticks(s, now);
  82    ticks = s->tim_arr - (now_ticks - s->tick_offset);
  83
  84    DB_PRINT("Alarm set in %d ticks\n", (int) ticks);
  85
  86    s->hit_time = muldiv64((ticks + (uint64_t) now_ticks) * (s->tim_psc + 1),
  87                               1000000000ULL, s->freq_hz);
  88
  89    timer_mod(s->timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + s->hit_time);
  90    DB_PRINT("Wait Time: %" PRId64 " ticks\n", s->hit_time);
  91}
  92
  93static void stm32f2xx_timer_reset(DeviceState *dev)
  94{
  95    STM32F2XXTimerState *s = STM32F2XXTIMER(dev);
  96    int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
  97
  98    s->tim_cr1 = 0;
  99    s->tim_cr2 = 0;
 100    s->tim_smcr = 0;
 101    s->tim_dier = 0;
 102    s->tim_sr = 0;
 103    s->tim_egr = 0;
 104    s->tim_ccmr1 = 0;
 105    s->tim_ccmr2 = 0;
 106    s->tim_ccer = 0;
 107    s->tim_psc = 0;
 108    s->tim_arr = 0;
 109    s->tim_ccr1 = 0;
 110    s->tim_ccr2 = 0;
 111    s->tim_ccr3 = 0;
 112    s->tim_ccr4 = 0;
 113    s->tim_dcr = 0;
 114    s->tim_dmar = 0;
 115    s->tim_or = 0;
 116
 117    s->tick_offset = stm32f2xx_ns_to_ticks(s, now);
 118}
 119
 120static uint64_t stm32f2xx_timer_read(void *opaque, hwaddr offset,
 121                           unsigned size)
 122{
 123    STM32F2XXTimerState *s = opaque;
 124
 125    DB_PRINT("Read 0x%"HWADDR_PRIx"\n", offset);
 126
 127    switch (offset) {
 128    case TIM_CR1:
 129        return s->tim_cr1;
 130    case TIM_CR2:
 131        return s->tim_cr2;
 132    case TIM_SMCR:
 133        return s->tim_smcr;
 134    case TIM_DIER:
 135        return s->tim_dier;
 136    case TIM_SR:
 137        return s->tim_sr;
 138    case TIM_EGR:
 139        return s->tim_egr;
 140    case TIM_CCMR1:
 141        return s->tim_ccmr1;
 142    case TIM_CCMR2:
 143        return s->tim_ccmr2;
 144    case TIM_CCER:
 145        return s->tim_ccer;
 146    case TIM_CNT:
 147        return stm32f2xx_ns_to_ticks(s, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL)) -
 148               s->tick_offset;
 149    case TIM_PSC:
 150        return s->tim_psc;
 151    case TIM_ARR:
 152        return s->tim_arr;
 153    case TIM_CCR1:
 154        return s->tim_ccr1;
 155    case TIM_CCR2:
 156        return s->tim_ccr2;
 157    case TIM_CCR3:
 158        return s->tim_ccr3;
 159    case TIM_CCR4:
 160        return s->tim_ccr4;
 161    case TIM_DCR:
 162        return s->tim_dcr;
 163    case TIM_DMAR:
 164        return s->tim_dmar;
 165    case TIM_OR:
 166        return s->tim_or;
 167    default:
 168        qemu_log_mask(LOG_GUEST_ERROR,
 169                      "%s: Bad offset 0x%"HWADDR_PRIx"\n", __func__, offset);
 170    }
 171
 172    return 0;
 173}
 174
 175static void stm32f2xx_timer_write(void *opaque, hwaddr offset,
 176                        uint64_t val64, unsigned size)
 177{
 178    STM32F2XXTimerState *s = opaque;
 179    uint32_t value = val64;
 180    int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
 181    uint32_t timer_val = 0;
 182
 183    DB_PRINT("Write 0x%x, 0x%"HWADDR_PRIx"\n", value, offset);
 184
 185    switch (offset) {
 186    case TIM_CR1:
 187        s->tim_cr1 = value;
 188        return;
 189    case TIM_CR2:
 190        s->tim_cr2 = value;
 191        return;
 192    case TIM_SMCR:
 193        s->tim_smcr = value;
 194        return;
 195    case TIM_DIER:
 196        s->tim_dier = value;
 197        return;
 198    case TIM_SR:
 199        /* This is set by hardware and cleared by software */
 200        s->tim_sr &= value;
 201        return;
 202    case TIM_EGR:
 203        s->tim_egr = value;
 204        if (s->tim_egr & TIM_EGR_UG) {
 205            timer_val = 0;
 206            break;
 207        }
 208        return;
 209    case TIM_CCMR1:
 210        s->tim_ccmr1 = value;
 211        return;
 212    case TIM_CCMR2:
 213        s->tim_ccmr2 = value;
 214        return;
 215    case TIM_CCER:
 216        s->tim_ccer = value;
 217        return;
 218    case TIM_PSC:
 219        timer_val = stm32f2xx_ns_to_ticks(s, now) - s->tick_offset;
 220        s->tim_psc = value & 0xFFFF;
 221        value = timer_val;
 222        break;
 223    case TIM_CNT:
 224        timer_val = value;
 225        break;
 226    case TIM_ARR:
 227        s->tim_arr = value;
 228        stm32f2xx_timer_set_alarm(s, now);
 229        return;
 230    case TIM_CCR1:
 231        s->tim_ccr1 = value;
 232        return;
 233    case TIM_CCR2:
 234        s->tim_ccr2 = value;
 235        return;
 236    case TIM_CCR3:
 237        s->tim_ccr3 = value;
 238        return;
 239    case TIM_CCR4:
 240        s->tim_ccr4 = value;
 241        return;
 242    case TIM_DCR:
 243        s->tim_dcr = value;
 244        return;
 245    case TIM_DMAR:
 246        s->tim_dmar = value;
 247        return;
 248    case TIM_OR:
 249        s->tim_or = value;
 250        return;
 251    default:
 252        qemu_log_mask(LOG_GUEST_ERROR,
 253                      "%s: Bad offset 0x%"HWADDR_PRIx"\n", __func__, offset);
 254        return;
 255    }
 256
 257    /* This means that a register write has affected the timer in a way that
 258     * requires a refresh of both tick_offset and the alarm.
 259     */
 260    s->tick_offset = stm32f2xx_ns_to_ticks(s, now) - timer_val;
 261    stm32f2xx_timer_set_alarm(s, now);
 262}
 263
 264static const MemoryRegionOps stm32f2xx_timer_ops = {
 265    .read = stm32f2xx_timer_read,
 266    .write = stm32f2xx_timer_write,
 267    .endianness = DEVICE_NATIVE_ENDIAN,
 268};
 269
 270static const VMStateDescription vmstate_stm32f2xx_timer = {
 271    .name = TYPE_STM32F2XX_TIMER,
 272    .version_id = 1,
 273    .minimum_version_id = 1,
 274    .fields = (VMStateField[]) {
 275        VMSTATE_INT64(tick_offset, STM32F2XXTimerState),
 276        VMSTATE_UINT32(tim_cr1, STM32F2XXTimerState),
 277        VMSTATE_UINT32(tim_cr2, STM32F2XXTimerState),
 278        VMSTATE_UINT32(tim_smcr, STM32F2XXTimerState),
 279        VMSTATE_UINT32(tim_dier, STM32F2XXTimerState),
 280        VMSTATE_UINT32(tim_sr, STM32F2XXTimerState),
 281        VMSTATE_UINT32(tim_egr, STM32F2XXTimerState),
 282        VMSTATE_UINT32(tim_ccmr1, STM32F2XXTimerState),
 283        VMSTATE_UINT32(tim_ccmr2, STM32F2XXTimerState),
 284        VMSTATE_UINT32(tim_ccer, STM32F2XXTimerState),
 285        VMSTATE_UINT32(tim_psc, STM32F2XXTimerState),
 286        VMSTATE_UINT32(tim_arr, STM32F2XXTimerState),
 287        VMSTATE_UINT32(tim_ccr1, STM32F2XXTimerState),
 288        VMSTATE_UINT32(tim_ccr2, STM32F2XXTimerState),
 289        VMSTATE_UINT32(tim_ccr3, STM32F2XXTimerState),
 290        VMSTATE_UINT32(tim_ccr4, STM32F2XXTimerState),
 291        VMSTATE_UINT32(tim_dcr, STM32F2XXTimerState),
 292        VMSTATE_UINT32(tim_dmar, STM32F2XXTimerState),
 293        VMSTATE_UINT32(tim_or, STM32F2XXTimerState),
 294        VMSTATE_END_OF_LIST()
 295    }
 296};
 297
 298static Property stm32f2xx_timer_properties[] = {
 299    DEFINE_PROP_UINT64("clock-frequency", struct STM32F2XXTimerState,
 300                       freq_hz, 1000000000),
 301    DEFINE_PROP_END_OF_LIST(),
 302};
 303
 304static void stm32f2xx_timer_init(Object *obj)
 305{
 306    STM32F2XXTimerState *s = STM32F2XXTIMER(obj);
 307
 308    sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->irq);
 309
 310    memory_region_init_io(&s->iomem, obj, &stm32f2xx_timer_ops, s,
 311                          "stm32f2xx_timer", 0x400);
 312    sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->iomem);
 313
 314    s->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, stm32f2xx_timer_interrupt, s);
 315}
 316
 317static void stm32f2xx_timer_class_init(ObjectClass *klass, void *data)
 318{
 319    DeviceClass *dc = DEVICE_CLASS(klass);
 320
 321    dc->reset = stm32f2xx_timer_reset;
 322    dc->props = stm32f2xx_timer_properties;
 323    dc->vmsd = &vmstate_stm32f2xx_timer;
 324}
 325
 326static const TypeInfo stm32f2xx_timer_info = {
 327    .name          = TYPE_STM32F2XX_TIMER,
 328    .parent        = TYPE_SYS_BUS_DEVICE,
 329    .instance_size = sizeof(STM32F2XXTimerState),
 330    .instance_init = stm32f2xx_timer_init,
 331    .class_init    = stm32f2xx_timer_class_init,
 332};
 333
 334static void stm32f2xx_timer_register_types(void)
 335{
 336    type_register_static(&stm32f2xx_timer_info);
 337}
 338
 339type_init(stm32f2xx_timer_register_types)
 340