xref: /openbmc/qemu/hw/timer/stm32f2xx_timer.c (revision 77a8257e)
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 "hw/timer/stm32f2xx_timer.h"
26 
27 #ifndef STM_TIMER_ERR_DEBUG
28 #define STM_TIMER_ERR_DEBUG 0
29 #endif
30 
31 #define DB_PRINT_L(lvl, fmt, args...) do { \
32     if (STM_TIMER_ERR_DEBUG >= lvl) { \
33         qemu_log("%s: " fmt, __func__, ## args); \
34     } \
35 } while (0);
36 
37 #define DB_PRINT(fmt, args...) DB_PRINT_L(1, fmt, ## args)
38 
39 static void stm32f2xx_timer_set_alarm(STM32F2XXTimerState *s, int64_t now);
40 
41 static void stm32f2xx_timer_interrupt(void *opaque)
42 {
43     STM32F2XXTimerState *s = opaque;
44 
45     DB_PRINT("Interrupt\n");
46 
47     if (s->tim_dier & TIM_DIER_UIE && s->tim_cr1 & TIM_CR1_CEN) {
48         s->tim_sr |= 1;
49         qemu_irq_pulse(s->irq);
50         stm32f2xx_timer_set_alarm(s, s->hit_time);
51     }
52 }
53 
54 static inline int64_t stm32f2xx_ns_to_ticks(STM32F2XXTimerState *s, int64_t t)
55 {
56     return muldiv64(t, s->freq_hz, 1000000000ULL) / (s->tim_psc + 1);
57 }
58 
59 static void stm32f2xx_timer_set_alarm(STM32F2XXTimerState *s, int64_t now)
60 {
61     uint64_t ticks;
62     int64_t now_ticks;
63 
64     if (s->tim_arr == 0) {
65         return;
66     }
67 
68     DB_PRINT("Alarm set at: 0x%x\n", s->tim_cr1);
69 
70     now_ticks = stm32f2xx_ns_to_ticks(s, now);
71     ticks = s->tim_arr - (now_ticks - s->tick_offset);
72 
73     DB_PRINT("Alarm set in %d ticks\n", (int) ticks);
74 
75     s->hit_time = muldiv64((ticks + (uint64_t) now_ticks) * (s->tim_psc + 1),
76                                1000000000ULL, s->freq_hz);
77 
78     timer_mod(s->timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + s->hit_time);
79     DB_PRINT("Wait Time: %" PRId64 " ticks\n", s->hit_time);
80 }
81 
82 static void stm32f2xx_timer_reset(DeviceState *dev)
83 {
84     STM32F2XXTimerState *s = STM32F2XXTIMER(dev);
85     int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
86 
87     s->tim_cr1 = 0;
88     s->tim_cr2 = 0;
89     s->tim_smcr = 0;
90     s->tim_dier = 0;
91     s->tim_sr = 0;
92     s->tim_egr = 0;
93     s->tim_ccmr1 = 0;
94     s->tim_ccmr2 = 0;
95     s->tim_ccer = 0;
96     s->tim_psc = 0;
97     s->tim_arr = 0;
98     s->tim_ccr1 = 0;
99     s->tim_ccr2 = 0;
100     s->tim_ccr3 = 0;
101     s->tim_ccr4 = 0;
102     s->tim_dcr = 0;
103     s->tim_dmar = 0;
104     s->tim_or = 0;
105 
106     s->tick_offset = stm32f2xx_ns_to_ticks(s, now);
107 }
108 
109 static uint64_t stm32f2xx_timer_read(void *opaque, hwaddr offset,
110                            unsigned size)
111 {
112     STM32F2XXTimerState *s = opaque;
113 
114     DB_PRINT("Read 0x%"HWADDR_PRIx"\n", offset);
115 
116     switch (offset) {
117     case TIM_CR1:
118         return s->tim_cr1;
119     case TIM_CR2:
120         return s->tim_cr2;
121     case TIM_SMCR:
122         return s->tim_smcr;
123     case TIM_DIER:
124         return s->tim_dier;
125     case TIM_SR:
126         return s->tim_sr;
127     case TIM_EGR:
128         return s->tim_egr;
129     case TIM_CCMR1:
130         return s->tim_ccmr1;
131     case TIM_CCMR2:
132         return s->tim_ccmr2;
133     case TIM_CCER:
134         return s->tim_ccer;
135     case TIM_CNT:
136         return stm32f2xx_ns_to_ticks(s, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL)) -
137                s->tick_offset;
138     case TIM_PSC:
139         return s->tim_psc;
140     case TIM_ARR:
141         return s->tim_arr;
142     case TIM_CCR1:
143         return s->tim_ccr1;
144     case TIM_CCR2:
145         return s->tim_ccr2;
146     case TIM_CCR3:
147         return s->tim_ccr3;
148     case TIM_CCR4:
149         return s->tim_ccr4;
150     case TIM_DCR:
151         return s->tim_dcr;
152     case TIM_DMAR:
153         return s->tim_dmar;
154     case TIM_OR:
155         return s->tim_or;
156     default:
157         qemu_log_mask(LOG_GUEST_ERROR,
158                       "%s: Bad offset 0x%"HWADDR_PRIx"\n", __func__, offset);
159     }
160 
161     return 0;
162 }
163 
164 static void stm32f2xx_timer_write(void *opaque, hwaddr offset,
165                         uint64_t val64, unsigned size)
166 {
167     STM32F2XXTimerState *s = opaque;
168     uint32_t value = val64;
169     int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
170     uint32_t timer_val = 0;
171 
172     DB_PRINT("Write 0x%x, 0x%"HWADDR_PRIx"\n", value, offset);
173 
174     switch (offset) {
175     case TIM_CR1:
176         s->tim_cr1 = value;
177         return;
178     case TIM_CR2:
179         s->tim_cr2 = value;
180         return;
181     case TIM_SMCR:
182         s->tim_smcr = value;
183         return;
184     case TIM_DIER:
185         s->tim_dier = value;
186         return;
187     case TIM_SR:
188         /* This is set by hardware and cleared by software */
189         s->tim_sr &= value;
190         return;
191     case TIM_EGR:
192         s->tim_egr = value;
193         if (s->tim_egr & TIM_EGR_UG) {
194             timer_val = 0;
195             break;
196         }
197         return;
198     case TIM_CCMR1:
199         s->tim_ccmr1 = value;
200         return;
201     case TIM_CCMR2:
202         s->tim_ccmr2 = value;
203         return;
204     case TIM_CCER:
205         s->tim_ccer = value;
206         return;
207     case TIM_PSC:
208         timer_val = stm32f2xx_ns_to_ticks(s, now) - s->tick_offset;
209         s->tim_psc = value;
210         value = timer_val;
211         break;
212     case TIM_CNT:
213         timer_val = value;
214         break;
215     case TIM_ARR:
216         s->tim_arr = value;
217         stm32f2xx_timer_set_alarm(s, now);
218         return;
219     case TIM_CCR1:
220         s->tim_ccr1 = value;
221         return;
222     case TIM_CCR2:
223         s->tim_ccr2 = value;
224         return;
225     case TIM_CCR3:
226         s->tim_ccr3 = value;
227         return;
228     case TIM_CCR4:
229         s->tim_ccr4 = value;
230         return;
231     case TIM_DCR:
232         s->tim_dcr = value;
233         return;
234     case TIM_DMAR:
235         s->tim_dmar = value;
236         return;
237     case TIM_OR:
238         s->tim_or = value;
239         return;
240     default:
241         qemu_log_mask(LOG_GUEST_ERROR,
242                       "%s: Bad offset 0x%"HWADDR_PRIx"\n", __func__, offset);
243         return;
244     }
245 
246     /* This means that a register write has affected the timer in a way that
247      * requires a refresh of both tick_offset and the alarm.
248      */
249     s->tick_offset = stm32f2xx_ns_to_ticks(s, now) - timer_val;
250     stm32f2xx_timer_set_alarm(s, now);
251 }
252 
253 static const MemoryRegionOps stm32f2xx_timer_ops = {
254     .read = stm32f2xx_timer_read,
255     .write = stm32f2xx_timer_write,
256     .endianness = DEVICE_NATIVE_ENDIAN,
257 };
258 
259 static const VMStateDescription vmstate_stm32f2xx_timer = {
260     .name = TYPE_STM32F2XX_TIMER,
261     .version_id = 1,
262     .minimum_version_id = 1,
263     .fields = (VMStateField[]) {
264         VMSTATE_INT64(tick_offset, STM32F2XXTimerState),
265         VMSTATE_UINT32(tim_cr1, STM32F2XXTimerState),
266         VMSTATE_UINT32(tim_cr2, STM32F2XXTimerState),
267         VMSTATE_UINT32(tim_smcr, STM32F2XXTimerState),
268         VMSTATE_UINT32(tim_dier, STM32F2XXTimerState),
269         VMSTATE_UINT32(tim_sr, STM32F2XXTimerState),
270         VMSTATE_UINT32(tim_egr, STM32F2XXTimerState),
271         VMSTATE_UINT32(tim_ccmr1, STM32F2XXTimerState),
272         VMSTATE_UINT32(tim_ccmr2, STM32F2XXTimerState),
273         VMSTATE_UINT32(tim_ccer, STM32F2XXTimerState),
274         VMSTATE_UINT32(tim_psc, STM32F2XXTimerState),
275         VMSTATE_UINT32(tim_arr, STM32F2XXTimerState),
276         VMSTATE_UINT32(tim_ccr1, STM32F2XXTimerState),
277         VMSTATE_UINT32(tim_ccr2, STM32F2XXTimerState),
278         VMSTATE_UINT32(tim_ccr3, STM32F2XXTimerState),
279         VMSTATE_UINT32(tim_ccr4, STM32F2XXTimerState),
280         VMSTATE_UINT32(tim_dcr, STM32F2XXTimerState),
281         VMSTATE_UINT32(tim_dmar, STM32F2XXTimerState),
282         VMSTATE_UINT32(tim_or, STM32F2XXTimerState),
283         VMSTATE_END_OF_LIST()
284     }
285 };
286 
287 static Property stm32f2xx_timer_properties[] = {
288     DEFINE_PROP_UINT64("clock-frequency", struct STM32F2XXTimerState,
289                        freq_hz, 1000000000),
290     DEFINE_PROP_END_OF_LIST(),
291 };
292 
293 static void stm32f2xx_timer_init(Object *obj)
294 {
295     STM32F2XXTimerState *s = STM32F2XXTIMER(obj);
296 
297     sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->irq);
298 
299     memory_region_init_io(&s->iomem, obj, &stm32f2xx_timer_ops, s,
300                           "stm32f2xx_timer", 0x4000);
301     sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->iomem);
302 
303     s->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, stm32f2xx_timer_interrupt, s);
304 }
305 
306 static void stm32f2xx_timer_class_init(ObjectClass *klass, void *data)
307 {
308     DeviceClass *dc = DEVICE_CLASS(klass);
309 
310     dc->reset = stm32f2xx_timer_reset;
311     dc->props = stm32f2xx_timer_properties;
312     dc->vmsd = &vmstate_stm32f2xx_timer;
313 }
314 
315 static const TypeInfo stm32f2xx_timer_info = {
316     .name          = TYPE_STM32F2XX_TIMER,
317     .parent        = TYPE_SYS_BUS_DEVICE,
318     .instance_size = sizeof(STM32F2XXTimerState),
319     .instance_init = stm32f2xx_timer_init,
320     .class_init    = stm32f2xx_timer_class_init,
321 };
322 
323 static void stm32f2xx_timer_register_types(void)
324 {
325     type_register_static(&stm32f2xx_timer_info);
326 }
327 
328 type_init(stm32f2xx_timer_register_types)
329