xref: /openbmc/qemu/hw/timer/stm32f2xx_timer.c (revision 64552b6b)
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/irq.h"
27 #include "hw/timer/stm32f2xx_timer.h"
28 #include "qemu/log.h"
29 #include "qemu/module.h"
30 
31 #ifndef STM_TIMER_ERR_DEBUG
32 #define STM_TIMER_ERR_DEBUG 0
33 #endif
34 
35 #define DB_PRINT_L(lvl, fmt, args...) do { \
36     if (STM_TIMER_ERR_DEBUG >= lvl) { \
37         qemu_log("%s: " fmt, __func__, ## args); \
38     } \
39 } while (0)
40 
41 #define DB_PRINT(fmt, args...) DB_PRINT_L(1, fmt, ## args)
42 
43 static void stm32f2xx_timer_set_alarm(STM32F2XXTimerState *s, int64_t now);
44 
45 static void stm32f2xx_timer_interrupt(void *opaque)
46 {
47     STM32F2XXTimerState *s = opaque;
48 
49     DB_PRINT("Interrupt\n");
50 
51     if (s->tim_dier & TIM_DIER_UIE && s->tim_cr1 & TIM_CR1_CEN) {
52         s->tim_sr |= 1;
53         qemu_irq_pulse(s->irq);
54         stm32f2xx_timer_set_alarm(s, s->hit_time);
55     }
56 
57     if (s->tim_ccmr1 & (TIM_CCMR1_OC2M2 | TIM_CCMR1_OC2M1) &&
58         !(s->tim_ccmr1 & TIM_CCMR1_OC2M0) &&
59         s->tim_ccmr1 & TIM_CCMR1_OC2PE &&
60         s->tim_ccer & TIM_CCER_CC2E) {
61         /* PWM 2 - Mode 1 */
62         DB_PRINT("PWM2 Duty Cycle: %d%%\n",
63                 s->tim_ccr2 / (100 * (s->tim_psc + 1)));
64     }
65 }
66 
67 static inline int64_t stm32f2xx_ns_to_ticks(STM32F2XXTimerState *s, int64_t t)
68 {
69     return muldiv64(t, s->freq_hz, 1000000000ULL) / (s->tim_psc + 1);
70 }
71 
72 static void stm32f2xx_timer_set_alarm(STM32F2XXTimerState *s, int64_t now)
73 {
74     uint64_t ticks;
75     int64_t now_ticks;
76 
77     if (s->tim_arr == 0) {
78         return;
79     }
80 
81     DB_PRINT("Alarm set at: 0x%x\n", s->tim_cr1);
82 
83     now_ticks = stm32f2xx_ns_to_ticks(s, now);
84     ticks = s->tim_arr - (now_ticks - s->tick_offset);
85 
86     DB_PRINT("Alarm set in %d ticks\n", (int) ticks);
87 
88     s->hit_time = muldiv64((ticks + (uint64_t) now_ticks) * (s->tim_psc + 1),
89                                1000000000ULL, s->freq_hz);
90 
91     timer_mod(s->timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + s->hit_time);
92     DB_PRINT("Wait Time: %" PRId64 " ticks\n", s->hit_time);
93 }
94 
95 static void stm32f2xx_timer_reset(DeviceState *dev)
96 {
97     STM32F2XXTimerState *s = STM32F2XXTIMER(dev);
98     int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
99 
100     s->tim_cr1 = 0;
101     s->tim_cr2 = 0;
102     s->tim_smcr = 0;
103     s->tim_dier = 0;
104     s->tim_sr = 0;
105     s->tim_egr = 0;
106     s->tim_ccmr1 = 0;
107     s->tim_ccmr2 = 0;
108     s->tim_ccer = 0;
109     s->tim_psc = 0;
110     s->tim_arr = 0;
111     s->tim_ccr1 = 0;
112     s->tim_ccr2 = 0;
113     s->tim_ccr3 = 0;
114     s->tim_ccr4 = 0;
115     s->tim_dcr = 0;
116     s->tim_dmar = 0;
117     s->tim_or = 0;
118 
119     s->tick_offset = stm32f2xx_ns_to_ticks(s, now);
120 }
121 
122 static uint64_t stm32f2xx_timer_read(void *opaque, hwaddr offset,
123                            unsigned size)
124 {
125     STM32F2XXTimerState *s = opaque;
126 
127     DB_PRINT("Read 0x%"HWADDR_PRIx"\n", offset);
128 
129     switch (offset) {
130     case TIM_CR1:
131         return s->tim_cr1;
132     case TIM_CR2:
133         return s->tim_cr2;
134     case TIM_SMCR:
135         return s->tim_smcr;
136     case TIM_DIER:
137         return s->tim_dier;
138     case TIM_SR:
139         return s->tim_sr;
140     case TIM_EGR:
141         return s->tim_egr;
142     case TIM_CCMR1:
143         return s->tim_ccmr1;
144     case TIM_CCMR2:
145         return s->tim_ccmr2;
146     case TIM_CCER:
147         return s->tim_ccer;
148     case TIM_CNT:
149         return stm32f2xx_ns_to_ticks(s, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL)) -
150                s->tick_offset;
151     case TIM_PSC:
152         return s->tim_psc;
153     case TIM_ARR:
154         return s->tim_arr;
155     case TIM_CCR1:
156         return s->tim_ccr1;
157     case TIM_CCR2:
158         return s->tim_ccr2;
159     case TIM_CCR3:
160         return s->tim_ccr3;
161     case TIM_CCR4:
162         return s->tim_ccr4;
163     case TIM_DCR:
164         return s->tim_dcr;
165     case TIM_DMAR:
166         return s->tim_dmar;
167     case TIM_OR:
168         return s->tim_or;
169     default:
170         qemu_log_mask(LOG_GUEST_ERROR,
171                       "%s: Bad offset 0x%"HWADDR_PRIx"\n", __func__, offset);
172     }
173 
174     return 0;
175 }
176 
177 static void stm32f2xx_timer_write(void *opaque, hwaddr offset,
178                         uint64_t val64, unsigned size)
179 {
180     STM32F2XXTimerState *s = opaque;
181     uint32_t value = val64;
182     int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
183     uint32_t timer_val = 0;
184 
185     DB_PRINT("Write 0x%x, 0x%"HWADDR_PRIx"\n", value, offset);
186 
187     switch (offset) {
188     case TIM_CR1:
189         s->tim_cr1 = value;
190         return;
191     case TIM_CR2:
192         s->tim_cr2 = value;
193         return;
194     case TIM_SMCR:
195         s->tim_smcr = value;
196         return;
197     case TIM_DIER:
198         s->tim_dier = value;
199         return;
200     case TIM_SR:
201         /* This is set by hardware and cleared by software */
202         s->tim_sr &= value;
203         return;
204     case TIM_EGR:
205         s->tim_egr = value;
206         if (s->tim_egr & TIM_EGR_UG) {
207             timer_val = 0;
208             break;
209         }
210         return;
211     case TIM_CCMR1:
212         s->tim_ccmr1 = value;
213         return;
214     case TIM_CCMR2:
215         s->tim_ccmr2 = value;
216         return;
217     case TIM_CCER:
218         s->tim_ccer = value;
219         return;
220     case TIM_PSC:
221         timer_val = stm32f2xx_ns_to_ticks(s, now) - s->tick_offset;
222         s->tim_psc = value & 0xFFFF;
223         value = timer_val;
224         break;
225     case TIM_CNT:
226         timer_val = value;
227         break;
228     case TIM_ARR:
229         s->tim_arr = value;
230         stm32f2xx_timer_set_alarm(s, now);
231         return;
232     case TIM_CCR1:
233         s->tim_ccr1 = value;
234         return;
235     case TIM_CCR2:
236         s->tim_ccr2 = value;
237         return;
238     case TIM_CCR3:
239         s->tim_ccr3 = value;
240         return;
241     case TIM_CCR4:
242         s->tim_ccr4 = value;
243         return;
244     case TIM_DCR:
245         s->tim_dcr = value;
246         return;
247     case TIM_DMAR:
248         s->tim_dmar = value;
249         return;
250     case TIM_OR:
251         s->tim_or = value;
252         return;
253     default:
254         qemu_log_mask(LOG_GUEST_ERROR,
255                       "%s: Bad offset 0x%"HWADDR_PRIx"\n", __func__, offset);
256         return;
257     }
258 
259     /* This means that a register write has affected the timer in a way that
260      * requires a refresh of both tick_offset and the alarm.
261      */
262     s->tick_offset = stm32f2xx_ns_to_ticks(s, now) - timer_val;
263     stm32f2xx_timer_set_alarm(s, now);
264 }
265 
266 static const MemoryRegionOps stm32f2xx_timer_ops = {
267     .read = stm32f2xx_timer_read,
268     .write = stm32f2xx_timer_write,
269     .endianness = DEVICE_NATIVE_ENDIAN,
270 };
271 
272 static const VMStateDescription vmstate_stm32f2xx_timer = {
273     .name = TYPE_STM32F2XX_TIMER,
274     .version_id = 1,
275     .minimum_version_id = 1,
276     .fields = (VMStateField[]) {
277         VMSTATE_INT64(tick_offset, STM32F2XXTimerState),
278         VMSTATE_UINT32(tim_cr1, STM32F2XXTimerState),
279         VMSTATE_UINT32(tim_cr2, STM32F2XXTimerState),
280         VMSTATE_UINT32(tim_smcr, STM32F2XXTimerState),
281         VMSTATE_UINT32(tim_dier, STM32F2XXTimerState),
282         VMSTATE_UINT32(tim_sr, STM32F2XXTimerState),
283         VMSTATE_UINT32(tim_egr, STM32F2XXTimerState),
284         VMSTATE_UINT32(tim_ccmr1, STM32F2XXTimerState),
285         VMSTATE_UINT32(tim_ccmr2, STM32F2XXTimerState),
286         VMSTATE_UINT32(tim_ccer, STM32F2XXTimerState),
287         VMSTATE_UINT32(tim_psc, STM32F2XXTimerState),
288         VMSTATE_UINT32(tim_arr, STM32F2XXTimerState),
289         VMSTATE_UINT32(tim_ccr1, STM32F2XXTimerState),
290         VMSTATE_UINT32(tim_ccr2, STM32F2XXTimerState),
291         VMSTATE_UINT32(tim_ccr3, STM32F2XXTimerState),
292         VMSTATE_UINT32(tim_ccr4, STM32F2XXTimerState),
293         VMSTATE_UINT32(tim_dcr, STM32F2XXTimerState),
294         VMSTATE_UINT32(tim_dmar, STM32F2XXTimerState),
295         VMSTATE_UINT32(tim_or, STM32F2XXTimerState),
296         VMSTATE_END_OF_LIST()
297     }
298 };
299 
300 static Property stm32f2xx_timer_properties[] = {
301     DEFINE_PROP_UINT64("clock-frequency", struct STM32F2XXTimerState,
302                        freq_hz, 1000000000),
303     DEFINE_PROP_END_OF_LIST(),
304 };
305 
306 static void stm32f2xx_timer_init(Object *obj)
307 {
308     STM32F2XXTimerState *s = STM32F2XXTIMER(obj);
309 
310     sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->irq);
311 
312     memory_region_init_io(&s->iomem, obj, &stm32f2xx_timer_ops, s,
313                           "stm32f2xx_timer", 0x400);
314     sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->iomem);
315 
316     s->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, stm32f2xx_timer_interrupt, s);
317 }
318 
319 static void stm32f2xx_timer_class_init(ObjectClass *klass, void *data)
320 {
321     DeviceClass *dc = DEVICE_CLASS(klass);
322 
323     dc->reset = stm32f2xx_timer_reset;
324     dc->props = stm32f2xx_timer_properties;
325     dc->vmsd = &vmstate_stm32f2xx_timer;
326 }
327 
328 static const TypeInfo stm32f2xx_timer_info = {
329     .name          = TYPE_STM32F2XX_TIMER,
330     .parent        = TYPE_SYS_BUS_DEVICE,
331     .instance_size = sizeof(STM32F2XXTimerState),
332     .instance_init = stm32f2xx_timer_init,
333     .class_init    = stm32f2xx_timer_class_init,
334 };
335 
336 static void stm32f2xx_timer_register_types(void)
337 {
338     type_register_static(&stm32f2xx_timer_info);
339 }
340 
341 type_init(stm32f2xx_timer_register_types)
342