xref: /openbmc/qemu/hw/timer/stm32f2xx_timer.c (revision 503bb0b9)
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     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 
65 static 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 
70 static 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 
93 static 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 
120 static 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 
175 static 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 
264 static const MemoryRegionOps stm32f2xx_timer_ops = {
265     .read = stm32f2xx_timer_read,
266     .write = stm32f2xx_timer_write,
267     .endianness = DEVICE_NATIVE_ENDIAN,
268 };
269 
270 static 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 
298 static Property stm32f2xx_timer_properties[] = {
299     DEFINE_PROP_UINT64("clock-frequency", struct STM32F2XXTimerState,
300                        freq_hz, 1000000000),
301     DEFINE_PROP_END_OF_LIST(),
302 };
303 
304 static 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 
317 static 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 
326 static 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 
334 static void stm32f2xx_timer_register_types(void)
335 {
336     type_register_static(&stm32f2xx_timer_info);
337 }
338 
339 type_init(stm32f2xx_timer_register_types)
340