xref: /openbmc/qemu/hw/timer/stm32f2xx_timer.c (revision 891f8dcd)
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 
41 static void stm32f2xx_timer_set_alarm(STM32F2XXTimerState *s, int64_t now);
42 
43 static 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 
56 static inline int64_t stm32f2xx_ns_to_ticks(STM32F2XXTimerState *s, int64_t t)
57 {
58     return muldiv64(t, s->freq_hz, 1000000000ULL) / (s->tim_psc + 1);
59 }
60 
61 static void stm32f2xx_timer_set_alarm(STM32F2XXTimerState *s, int64_t now)
62 {
63     uint64_t ticks;
64     int64_t now_ticks;
65 
66     if (s->tim_arr == 0) {
67         return;
68     }
69 
70     DB_PRINT("Alarm set at: 0x%x\n", s->tim_cr1);
71 
72     now_ticks = stm32f2xx_ns_to_ticks(s, now);
73     ticks = s->tim_arr - (now_ticks - s->tick_offset);
74 
75     DB_PRINT("Alarm set in %d ticks\n", (int) ticks);
76 
77     s->hit_time = muldiv64((ticks + (uint64_t) now_ticks) * (s->tim_psc + 1),
78                                1000000000ULL, s->freq_hz);
79 
80     timer_mod(s->timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + s->hit_time);
81     DB_PRINT("Wait Time: %" PRId64 " ticks\n", s->hit_time);
82 }
83 
84 static void stm32f2xx_timer_reset(DeviceState *dev)
85 {
86     STM32F2XXTimerState *s = STM32F2XXTIMER(dev);
87     int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
88 
89     s->tim_cr1 = 0;
90     s->tim_cr2 = 0;
91     s->tim_smcr = 0;
92     s->tim_dier = 0;
93     s->tim_sr = 0;
94     s->tim_egr = 0;
95     s->tim_ccmr1 = 0;
96     s->tim_ccmr2 = 0;
97     s->tim_ccer = 0;
98     s->tim_psc = 0;
99     s->tim_arr = 0;
100     s->tim_ccr1 = 0;
101     s->tim_ccr2 = 0;
102     s->tim_ccr3 = 0;
103     s->tim_ccr4 = 0;
104     s->tim_dcr = 0;
105     s->tim_dmar = 0;
106     s->tim_or = 0;
107 
108     s->tick_offset = stm32f2xx_ns_to_ticks(s, now);
109 }
110 
111 static uint64_t stm32f2xx_timer_read(void *opaque, hwaddr offset,
112                            unsigned size)
113 {
114     STM32F2XXTimerState *s = opaque;
115 
116     DB_PRINT("Read 0x%"HWADDR_PRIx"\n", offset);
117 
118     switch (offset) {
119     case TIM_CR1:
120         return s->tim_cr1;
121     case TIM_CR2:
122         return s->tim_cr2;
123     case TIM_SMCR:
124         return s->tim_smcr;
125     case TIM_DIER:
126         return s->tim_dier;
127     case TIM_SR:
128         return s->tim_sr;
129     case TIM_EGR:
130         return s->tim_egr;
131     case TIM_CCMR1:
132         return s->tim_ccmr1;
133     case TIM_CCMR2:
134         return s->tim_ccmr2;
135     case TIM_CCER:
136         return s->tim_ccer;
137     case TIM_CNT:
138         return stm32f2xx_ns_to_ticks(s, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL)) -
139                s->tick_offset;
140     case TIM_PSC:
141         return s->tim_psc;
142     case TIM_ARR:
143         return s->tim_arr;
144     case TIM_CCR1:
145         return s->tim_ccr1;
146     case TIM_CCR2:
147         return s->tim_ccr2;
148     case TIM_CCR3:
149         return s->tim_ccr3;
150     case TIM_CCR4:
151         return s->tim_ccr4;
152     case TIM_DCR:
153         return s->tim_dcr;
154     case TIM_DMAR:
155         return s->tim_dmar;
156     case TIM_OR:
157         return s->tim_or;
158     default:
159         qemu_log_mask(LOG_GUEST_ERROR,
160                       "%s: Bad offset 0x%"HWADDR_PRIx"\n", __func__, offset);
161     }
162 
163     return 0;
164 }
165 
166 static void stm32f2xx_timer_write(void *opaque, hwaddr offset,
167                         uint64_t val64, unsigned size)
168 {
169     STM32F2XXTimerState *s = opaque;
170     uint32_t value = val64;
171     int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
172     uint32_t timer_val = 0;
173 
174     DB_PRINT("Write 0x%x, 0x%"HWADDR_PRIx"\n", value, offset);
175 
176     switch (offset) {
177     case TIM_CR1:
178         s->tim_cr1 = value;
179         return;
180     case TIM_CR2:
181         s->tim_cr2 = value;
182         return;
183     case TIM_SMCR:
184         s->tim_smcr = value;
185         return;
186     case TIM_DIER:
187         s->tim_dier = value;
188         return;
189     case TIM_SR:
190         /* This is set by hardware and cleared by software */
191         s->tim_sr &= value;
192         return;
193     case TIM_EGR:
194         s->tim_egr = value;
195         if (s->tim_egr & TIM_EGR_UG) {
196             timer_val = 0;
197             break;
198         }
199         return;
200     case TIM_CCMR1:
201         s->tim_ccmr1 = value;
202         return;
203     case TIM_CCMR2:
204         s->tim_ccmr2 = value;
205         return;
206     case TIM_CCER:
207         s->tim_ccer = value;
208         return;
209     case TIM_PSC:
210         timer_val = stm32f2xx_ns_to_ticks(s, now) - s->tick_offset;
211         s->tim_psc = value;
212         value = timer_val;
213         break;
214     case TIM_CNT:
215         timer_val = value;
216         break;
217     case TIM_ARR:
218         s->tim_arr = value;
219         stm32f2xx_timer_set_alarm(s, now);
220         return;
221     case TIM_CCR1:
222         s->tim_ccr1 = value;
223         return;
224     case TIM_CCR2:
225         s->tim_ccr2 = value;
226         return;
227     case TIM_CCR3:
228         s->tim_ccr3 = value;
229         return;
230     case TIM_CCR4:
231         s->tim_ccr4 = value;
232         return;
233     case TIM_DCR:
234         s->tim_dcr = value;
235         return;
236     case TIM_DMAR:
237         s->tim_dmar = value;
238         return;
239     case TIM_OR:
240         s->tim_or = value;
241         return;
242     default:
243         qemu_log_mask(LOG_GUEST_ERROR,
244                       "%s: Bad offset 0x%"HWADDR_PRIx"\n", __func__, offset);
245         return;
246     }
247 
248     /* This means that a register write has affected the timer in a way that
249      * requires a refresh of both tick_offset and the alarm.
250      */
251     s->tick_offset = stm32f2xx_ns_to_ticks(s, now) - timer_val;
252     stm32f2xx_timer_set_alarm(s, now);
253 }
254 
255 static const MemoryRegionOps stm32f2xx_timer_ops = {
256     .read = stm32f2xx_timer_read,
257     .write = stm32f2xx_timer_write,
258     .endianness = DEVICE_NATIVE_ENDIAN,
259 };
260 
261 static const VMStateDescription vmstate_stm32f2xx_timer = {
262     .name = TYPE_STM32F2XX_TIMER,
263     .version_id = 1,
264     .minimum_version_id = 1,
265     .fields = (VMStateField[]) {
266         VMSTATE_INT64(tick_offset, STM32F2XXTimerState),
267         VMSTATE_UINT32(tim_cr1, STM32F2XXTimerState),
268         VMSTATE_UINT32(tim_cr2, STM32F2XXTimerState),
269         VMSTATE_UINT32(tim_smcr, STM32F2XXTimerState),
270         VMSTATE_UINT32(tim_dier, STM32F2XXTimerState),
271         VMSTATE_UINT32(tim_sr, STM32F2XXTimerState),
272         VMSTATE_UINT32(tim_egr, STM32F2XXTimerState),
273         VMSTATE_UINT32(tim_ccmr1, STM32F2XXTimerState),
274         VMSTATE_UINT32(tim_ccmr2, STM32F2XXTimerState),
275         VMSTATE_UINT32(tim_ccer, STM32F2XXTimerState),
276         VMSTATE_UINT32(tim_psc, STM32F2XXTimerState),
277         VMSTATE_UINT32(tim_arr, STM32F2XXTimerState),
278         VMSTATE_UINT32(tim_ccr1, STM32F2XXTimerState),
279         VMSTATE_UINT32(tim_ccr2, STM32F2XXTimerState),
280         VMSTATE_UINT32(tim_ccr3, STM32F2XXTimerState),
281         VMSTATE_UINT32(tim_ccr4, STM32F2XXTimerState),
282         VMSTATE_UINT32(tim_dcr, STM32F2XXTimerState),
283         VMSTATE_UINT32(tim_dmar, STM32F2XXTimerState),
284         VMSTATE_UINT32(tim_or, STM32F2XXTimerState),
285         VMSTATE_END_OF_LIST()
286     }
287 };
288 
289 static Property stm32f2xx_timer_properties[] = {
290     DEFINE_PROP_UINT64("clock-frequency", struct STM32F2XXTimerState,
291                        freq_hz, 1000000000),
292     DEFINE_PROP_END_OF_LIST(),
293 };
294 
295 static void stm32f2xx_timer_init(Object *obj)
296 {
297     STM32F2XXTimerState *s = STM32F2XXTIMER(obj);
298 
299     sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->irq);
300 
301     memory_region_init_io(&s->iomem, obj, &stm32f2xx_timer_ops, s,
302                           "stm32f2xx_timer", 0x4000);
303     sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->iomem);
304 
305     s->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, stm32f2xx_timer_interrupt, s);
306 }
307 
308 static void stm32f2xx_timer_class_init(ObjectClass *klass, void *data)
309 {
310     DeviceClass *dc = DEVICE_CLASS(klass);
311 
312     dc->reset = stm32f2xx_timer_reset;
313     dc->props = stm32f2xx_timer_properties;
314     dc->vmsd = &vmstate_stm32f2xx_timer;
315 }
316 
317 static const TypeInfo stm32f2xx_timer_info = {
318     .name          = TYPE_STM32F2XX_TIMER,
319     .parent        = TYPE_SYS_BUS_DEVICE,
320     .instance_size = sizeof(STM32F2XXTimerState),
321     .instance_init = stm32f2xx_timer_init,
322     .class_init    = stm32f2xx_timer_class_init,
323 };
324 
325 static void stm32f2xx_timer_register_types(void)
326 {
327     type_register_static(&stm32f2xx_timer_info);
328 }
329 
330 type_init(stm32f2xx_timer_register_types)
331