xref: /openbmc/qemu/hw/timer/stm32f2xx_timer.c (revision 500eb6db)
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 #include "qemu/module.h"
29 
30 #ifndef STM_TIMER_ERR_DEBUG
31 #define STM_TIMER_ERR_DEBUG 0
32 #endif
33 
34 #define DB_PRINT_L(lvl, fmt, args...) do { \
35     if (STM_TIMER_ERR_DEBUG >= lvl) { \
36         qemu_log("%s: " fmt, __func__, ## args); \
37     } \
38 } while (0)
39 
40 #define DB_PRINT(fmt, args...) DB_PRINT_L(1, fmt, ## args)
41 
42 static void stm32f2xx_timer_set_alarm(STM32F2XXTimerState *s, int64_t now);
43 
44 static void stm32f2xx_timer_interrupt(void *opaque)
45 {
46     STM32F2XXTimerState *s = opaque;
47 
48     DB_PRINT("Interrupt\n");
49 
50     if (s->tim_dier & TIM_DIER_UIE && s->tim_cr1 & TIM_CR1_CEN) {
51         s->tim_sr |= 1;
52         qemu_irq_pulse(s->irq);
53         stm32f2xx_timer_set_alarm(s, s->hit_time);
54     }
55 
56     if (s->tim_ccmr1 & (TIM_CCMR1_OC2M2 | TIM_CCMR1_OC2M1) &&
57         !(s->tim_ccmr1 & TIM_CCMR1_OC2M0) &&
58         s->tim_ccmr1 & TIM_CCMR1_OC2PE &&
59         s->tim_ccer & TIM_CCER_CC2E) {
60         /* PWM 2 - Mode 1 */
61         DB_PRINT("PWM2 Duty Cycle: %d%%\n",
62                 s->tim_ccr2 / (100 * (s->tim_psc + 1)));
63     }
64 }
65 
66 static inline int64_t stm32f2xx_ns_to_ticks(STM32F2XXTimerState *s, int64_t t)
67 {
68     return muldiv64(t, s->freq_hz, 1000000000ULL) / (s->tim_psc + 1);
69 }
70 
71 static void stm32f2xx_timer_set_alarm(STM32F2XXTimerState *s, int64_t now)
72 {
73     uint64_t ticks;
74     int64_t now_ticks;
75 
76     if (s->tim_arr == 0) {
77         return;
78     }
79 
80     DB_PRINT("Alarm set at: 0x%x\n", s->tim_cr1);
81 
82     now_ticks = stm32f2xx_ns_to_ticks(s, now);
83     ticks = s->tim_arr - (now_ticks - s->tick_offset);
84 
85     DB_PRINT("Alarm set in %d ticks\n", (int) ticks);
86 
87     s->hit_time = muldiv64((ticks + (uint64_t) now_ticks) * (s->tim_psc + 1),
88                                1000000000ULL, s->freq_hz);
89 
90     timer_mod(s->timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + s->hit_time);
91     DB_PRINT("Wait Time: %" PRId64 " ticks\n", s->hit_time);
92 }
93 
94 static void stm32f2xx_timer_reset(DeviceState *dev)
95 {
96     STM32F2XXTimerState *s = STM32F2XXTIMER(dev);
97     int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
98 
99     s->tim_cr1 = 0;
100     s->tim_cr2 = 0;
101     s->tim_smcr = 0;
102     s->tim_dier = 0;
103     s->tim_sr = 0;
104     s->tim_egr = 0;
105     s->tim_ccmr1 = 0;
106     s->tim_ccmr2 = 0;
107     s->tim_ccer = 0;
108     s->tim_psc = 0;
109     s->tim_arr = 0;
110     s->tim_ccr1 = 0;
111     s->tim_ccr2 = 0;
112     s->tim_ccr3 = 0;
113     s->tim_ccr4 = 0;
114     s->tim_dcr = 0;
115     s->tim_dmar = 0;
116     s->tim_or = 0;
117 
118     s->tick_offset = stm32f2xx_ns_to_ticks(s, now);
119 }
120 
121 static uint64_t stm32f2xx_timer_read(void *opaque, hwaddr offset,
122                            unsigned size)
123 {
124     STM32F2XXTimerState *s = opaque;
125 
126     DB_PRINT("Read 0x%"HWADDR_PRIx"\n", offset);
127 
128     switch (offset) {
129     case TIM_CR1:
130         return s->tim_cr1;
131     case TIM_CR2:
132         return s->tim_cr2;
133     case TIM_SMCR:
134         return s->tim_smcr;
135     case TIM_DIER:
136         return s->tim_dier;
137     case TIM_SR:
138         return s->tim_sr;
139     case TIM_EGR:
140         return s->tim_egr;
141     case TIM_CCMR1:
142         return s->tim_ccmr1;
143     case TIM_CCMR2:
144         return s->tim_ccmr2;
145     case TIM_CCER:
146         return s->tim_ccer;
147     case TIM_CNT:
148         return stm32f2xx_ns_to_ticks(s, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL)) -
149                s->tick_offset;
150     case TIM_PSC:
151         return s->tim_psc;
152     case TIM_ARR:
153         return s->tim_arr;
154     case TIM_CCR1:
155         return s->tim_ccr1;
156     case TIM_CCR2:
157         return s->tim_ccr2;
158     case TIM_CCR3:
159         return s->tim_ccr3;
160     case TIM_CCR4:
161         return s->tim_ccr4;
162     case TIM_DCR:
163         return s->tim_dcr;
164     case TIM_DMAR:
165         return s->tim_dmar;
166     case TIM_OR:
167         return s->tim_or;
168     default:
169         qemu_log_mask(LOG_GUEST_ERROR,
170                       "%s: Bad offset 0x%"HWADDR_PRIx"\n", __func__, offset);
171     }
172 
173     return 0;
174 }
175 
176 static void stm32f2xx_timer_write(void *opaque, hwaddr offset,
177                         uint64_t val64, unsigned size)
178 {
179     STM32F2XXTimerState *s = opaque;
180     uint32_t value = val64;
181     int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
182     uint32_t timer_val = 0;
183 
184     DB_PRINT("Write 0x%x, 0x%"HWADDR_PRIx"\n", value, offset);
185 
186     switch (offset) {
187     case TIM_CR1:
188         s->tim_cr1 = value;
189         return;
190     case TIM_CR2:
191         s->tim_cr2 = value;
192         return;
193     case TIM_SMCR:
194         s->tim_smcr = value;
195         return;
196     case TIM_DIER:
197         s->tim_dier = value;
198         return;
199     case TIM_SR:
200         /* This is set by hardware and cleared by software */
201         s->tim_sr &= value;
202         return;
203     case TIM_EGR:
204         s->tim_egr = value;
205         if (s->tim_egr & TIM_EGR_UG) {
206             timer_val = 0;
207             break;
208         }
209         return;
210     case TIM_CCMR1:
211         s->tim_ccmr1 = value;
212         return;
213     case TIM_CCMR2:
214         s->tim_ccmr2 = value;
215         return;
216     case TIM_CCER:
217         s->tim_ccer = value;
218         return;
219     case TIM_PSC:
220         timer_val = stm32f2xx_ns_to_ticks(s, now) - s->tick_offset;
221         s->tim_psc = value & 0xFFFF;
222         value = timer_val;
223         break;
224     case TIM_CNT:
225         timer_val = value;
226         break;
227     case TIM_ARR:
228         s->tim_arr = value;
229         stm32f2xx_timer_set_alarm(s, now);
230         return;
231     case TIM_CCR1:
232         s->tim_ccr1 = value;
233         return;
234     case TIM_CCR2:
235         s->tim_ccr2 = value;
236         return;
237     case TIM_CCR3:
238         s->tim_ccr3 = value;
239         return;
240     case TIM_CCR4:
241         s->tim_ccr4 = value;
242         return;
243     case TIM_DCR:
244         s->tim_dcr = value;
245         return;
246     case TIM_DMAR:
247         s->tim_dmar = value;
248         return;
249     case TIM_OR:
250         s->tim_or = value;
251         return;
252     default:
253         qemu_log_mask(LOG_GUEST_ERROR,
254                       "%s: Bad offset 0x%"HWADDR_PRIx"\n", __func__, offset);
255         return;
256     }
257 
258     /* This means that a register write has affected the timer in a way that
259      * requires a refresh of both tick_offset and the alarm.
260      */
261     s->tick_offset = stm32f2xx_ns_to_ticks(s, now) - timer_val;
262     stm32f2xx_timer_set_alarm(s, now);
263 }
264 
265 static const MemoryRegionOps stm32f2xx_timer_ops = {
266     .read = stm32f2xx_timer_read,
267     .write = stm32f2xx_timer_write,
268     .endianness = DEVICE_NATIVE_ENDIAN,
269 };
270 
271 static const VMStateDescription vmstate_stm32f2xx_timer = {
272     .name = TYPE_STM32F2XX_TIMER,
273     .version_id = 1,
274     .minimum_version_id = 1,
275     .fields = (VMStateField[]) {
276         VMSTATE_INT64(tick_offset, STM32F2XXTimerState),
277         VMSTATE_UINT32(tim_cr1, STM32F2XXTimerState),
278         VMSTATE_UINT32(tim_cr2, STM32F2XXTimerState),
279         VMSTATE_UINT32(tim_smcr, STM32F2XXTimerState),
280         VMSTATE_UINT32(tim_dier, STM32F2XXTimerState),
281         VMSTATE_UINT32(tim_sr, STM32F2XXTimerState),
282         VMSTATE_UINT32(tim_egr, STM32F2XXTimerState),
283         VMSTATE_UINT32(tim_ccmr1, STM32F2XXTimerState),
284         VMSTATE_UINT32(tim_ccmr2, STM32F2XXTimerState),
285         VMSTATE_UINT32(tim_ccer, STM32F2XXTimerState),
286         VMSTATE_UINT32(tim_psc, STM32F2XXTimerState),
287         VMSTATE_UINT32(tim_arr, STM32F2XXTimerState),
288         VMSTATE_UINT32(tim_ccr1, STM32F2XXTimerState),
289         VMSTATE_UINT32(tim_ccr2, STM32F2XXTimerState),
290         VMSTATE_UINT32(tim_ccr3, STM32F2XXTimerState),
291         VMSTATE_UINT32(tim_ccr4, STM32F2XXTimerState),
292         VMSTATE_UINT32(tim_dcr, STM32F2XXTimerState),
293         VMSTATE_UINT32(tim_dmar, STM32F2XXTimerState),
294         VMSTATE_UINT32(tim_or, STM32F2XXTimerState),
295         VMSTATE_END_OF_LIST()
296     }
297 };
298 
299 static Property stm32f2xx_timer_properties[] = {
300     DEFINE_PROP_UINT64("clock-frequency", struct STM32F2XXTimerState,
301                        freq_hz, 1000000000),
302     DEFINE_PROP_END_OF_LIST(),
303 };
304 
305 static void stm32f2xx_timer_init(Object *obj)
306 {
307     STM32F2XXTimerState *s = STM32F2XXTIMER(obj);
308 
309     sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->irq);
310 
311     memory_region_init_io(&s->iomem, obj, &stm32f2xx_timer_ops, s,
312                           "stm32f2xx_timer", 0x400);
313     sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->iomem);
314 
315     s->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, stm32f2xx_timer_interrupt, s);
316 }
317 
318 static void stm32f2xx_timer_class_init(ObjectClass *klass, void *data)
319 {
320     DeviceClass *dc = DEVICE_CLASS(klass);
321 
322     dc->reset = stm32f2xx_timer_reset;
323     dc->props = stm32f2xx_timer_properties;
324     dc->vmsd = &vmstate_stm32f2xx_timer;
325 }
326 
327 static const TypeInfo stm32f2xx_timer_info = {
328     .name          = TYPE_STM32F2XX_TIMER,
329     .parent        = TYPE_SYS_BUS_DEVICE,
330     .instance_size = sizeof(STM32F2XXTimerState),
331     .instance_init = stm32f2xx_timer_init,
332     .class_init    = stm32f2xx_timer_class_init,
333 };
334 
335 static void stm32f2xx_timer_register_types(void)
336 {
337     type_register_static(&stm32f2xx_timer_info);
338 }
339 
340 type_init(stm32f2xx_timer_register_types)
341