xref: /openbmc/qemu/hw/timer/mss-timer.c (revision 37677d7d)
1 /*
2  * Block model of System timer present in
3  * Microsemi's SmartFusion2 and SmartFusion SoCs.
4  *
5  * Copyright (c) 2017 Subbaraya Sundeep <sundeep.lkml@gmail.com>.
6  *
7  * Permission is hereby granted, free of charge, to any person obtaining a copy
8  * of this software and associated documentation files (the "Software"), to deal
9  * in the Software without restriction, including without limitation the rights
10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11  * copies of the Software, and to permit persons to whom the Software is
12  * furnished to do so, subject to the following conditions:
13  *
14  * The above copyright notice and this permission notice shall be included in
15  * all copies or substantial portions of the Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23  * THE SOFTWARE.
24  */
25 
26 #include "qemu/osdep.h"
27 #include "qemu/main-loop.h"
28 #include "qemu/module.h"
29 #include "qemu/log.h"
30 #include "hw/timer/mss-timer.h"
31 
32 #ifndef MSS_TIMER_ERR_DEBUG
33 #define MSS_TIMER_ERR_DEBUG  0
34 #endif
35 
36 #define DB_PRINT_L(lvl, fmt, args...) do { \
37     if (MSS_TIMER_ERR_DEBUG >= lvl) { \
38         qemu_log("%s: " fmt "\n", __func__, ## args); \
39     } \
40 } while (0)
41 
42 #define DB_PRINT(fmt, args...) DB_PRINT_L(1, fmt, ## args)
43 
44 #define R_TIM_VAL         0
45 #define R_TIM_LOADVAL     1
46 #define R_TIM_BGLOADVAL   2
47 #define R_TIM_CTRL        3
48 #define R_TIM_RIS         4
49 #define R_TIM_MIS         5
50 
51 #define TIMER_CTRL_ENBL     (1 << 0)
52 #define TIMER_CTRL_ONESHOT  (1 << 1)
53 #define TIMER_CTRL_INTR     (1 << 2)
54 #define TIMER_RIS_ACK       (1 << 0)
55 #define TIMER_RST_CLR       (1 << 6)
56 #define TIMER_MODE          (1 << 0)
57 
58 static void timer_update_irq(struct Msf2Timer *st)
59 {
60     bool isr, ier;
61 
62     isr = !!(st->regs[R_TIM_RIS] & TIMER_RIS_ACK);
63     ier = !!(st->regs[R_TIM_CTRL] & TIMER_CTRL_INTR);
64     qemu_set_irq(st->irq, (ier && isr));
65 }
66 
67 static void timer_update(struct Msf2Timer *st)
68 {
69     uint64_t count;
70 
71     if (!(st->regs[R_TIM_CTRL] & TIMER_CTRL_ENBL)) {
72         ptimer_stop(st->ptimer);
73         return;
74     }
75 
76     count = st->regs[R_TIM_LOADVAL];
77     ptimer_set_limit(st->ptimer, count, 1);
78     ptimer_run(st->ptimer, 1);
79 }
80 
81 static uint64_t
82 timer_read(void *opaque, hwaddr offset, unsigned int size)
83 {
84     MSSTimerState *t = opaque;
85     hwaddr addr;
86     struct Msf2Timer *st;
87     uint32_t ret = 0;
88     int timer = 0;
89     int isr;
90     int ier;
91 
92     addr = offset >> 2;
93     /*
94      * Two independent timers has same base address.
95      * Based on address passed figure out which timer is being used.
96      */
97     if ((addr >= R_TIM1_MAX) && (addr < NUM_TIMERS * R_TIM1_MAX)) {
98         timer = 1;
99         addr -= R_TIM1_MAX;
100     }
101 
102     st = &t->timers[timer];
103 
104     switch (addr) {
105     case R_TIM_VAL:
106         ret = ptimer_get_count(st->ptimer);
107         break;
108 
109     case R_TIM_MIS:
110         isr = !!(st->regs[R_TIM_RIS] & TIMER_RIS_ACK);
111         ier = !!(st->regs[R_TIM_CTRL] & TIMER_CTRL_INTR);
112         ret = ier & isr;
113         break;
114 
115     default:
116         if (addr < R_TIM1_MAX) {
117             ret = st->regs[addr];
118         } else {
119             qemu_log_mask(LOG_GUEST_ERROR,
120                         TYPE_MSS_TIMER": 64-bit mode not supported\n");
121             return ret;
122         }
123         break;
124     }
125 
126     DB_PRINT("timer=%d 0x%" HWADDR_PRIx "=0x%" PRIx32, timer, offset,
127             ret);
128     return ret;
129 }
130 
131 static void
132 timer_write(void *opaque, hwaddr offset,
133             uint64_t val64, unsigned int size)
134 {
135     MSSTimerState *t = opaque;
136     hwaddr addr;
137     struct Msf2Timer *st;
138     int timer = 0;
139     uint32_t value = val64;
140 
141     addr = offset >> 2;
142     /*
143      * Two independent timers has same base address.
144      * Based on addr passed figure out which timer is being used.
145      */
146     if ((addr >= R_TIM1_MAX) && (addr < NUM_TIMERS * R_TIM1_MAX)) {
147         timer = 1;
148         addr -= R_TIM1_MAX;
149     }
150 
151     st = &t->timers[timer];
152 
153     DB_PRINT("addr=0x%" HWADDR_PRIx " val=0x%" PRIx32 " (timer=%d)", offset,
154             value, timer);
155 
156     switch (addr) {
157     case R_TIM_CTRL:
158         st->regs[R_TIM_CTRL] = value;
159         timer_update(st);
160         break;
161 
162     case R_TIM_RIS:
163         if (value & TIMER_RIS_ACK) {
164             st->regs[R_TIM_RIS] &= ~TIMER_RIS_ACK;
165         }
166         break;
167 
168     case R_TIM_LOADVAL:
169         st->regs[R_TIM_LOADVAL] = value;
170         if (st->regs[R_TIM_CTRL] & TIMER_CTRL_ENBL) {
171             timer_update(st);
172         }
173         break;
174 
175     case R_TIM_BGLOADVAL:
176         st->regs[R_TIM_BGLOADVAL] = value;
177         st->regs[R_TIM_LOADVAL] = value;
178         break;
179 
180     case R_TIM_VAL:
181     case R_TIM_MIS:
182         break;
183 
184     default:
185         if (addr < R_TIM1_MAX) {
186             st->regs[addr] = value;
187         } else {
188             qemu_log_mask(LOG_GUEST_ERROR,
189                         TYPE_MSS_TIMER": 64-bit mode not supported\n");
190             return;
191         }
192         break;
193     }
194     timer_update_irq(st);
195 }
196 
197 static const MemoryRegionOps timer_ops = {
198     .read = timer_read,
199     .write = timer_write,
200     .endianness = DEVICE_NATIVE_ENDIAN,
201     .valid = {
202         .min_access_size = 1,
203         .max_access_size = 4
204     }
205 };
206 
207 static void timer_hit(void *opaque)
208 {
209     struct Msf2Timer *st = opaque;
210 
211     st->regs[R_TIM_RIS] |= TIMER_RIS_ACK;
212 
213     if (!(st->regs[R_TIM_CTRL] & TIMER_CTRL_ONESHOT)) {
214         timer_update(st);
215     }
216     timer_update_irq(st);
217 }
218 
219 static void mss_timer_init(Object *obj)
220 {
221     MSSTimerState *t = MSS_TIMER(obj);
222     int i;
223 
224     /* Init all the ptimers.  */
225     for (i = 0; i < NUM_TIMERS; i++) {
226         struct Msf2Timer *st = &t->timers[i];
227 
228         st->bh = qemu_bh_new(timer_hit, st);
229         st->ptimer = ptimer_init(st->bh, PTIMER_POLICY_DEFAULT);
230         ptimer_set_freq(st->ptimer, t->freq_hz);
231         sysbus_init_irq(SYS_BUS_DEVICE(obj), &st->irq);
232     }
233 
234     memory_region_init_io(&t->mmio, OBJECT(t), &timer_ops, t, TYPE_MSS_TIMER,
235                           NUM_TIMERS * R_TIM1_MAX * 4);
236     sysbus_init_mmio(SYS_BUS_DEVICE(obj), &t->mmio);
237 }
238 
239 static const VMStateDescription vmstate_timers = {
240     .name = "mss-timer-block",
241     .version_id = 1,
242     .minimum_version_id = 1,
243     .fields = (VMStateField[]) {
244         VMSTATE_PTIMER(ptimer, struct Msf2Timer),
245         VMSTATE_UINT32_ARRAY(regs, struct Msf2Timer, R_TIM1_MAX),
246         VMSTATE_END_OF_LIST()
247     }
248 };
249 
250 static const VMStateDescription vmstate_mss_timer = {
251     .name = TYPE_MSS_TIMER,
252     .version_id = 1,
253     .minimum_version_id = 1,
254     .fields = (VMStateField[]) {
255         VMSTATE_UINT32(freq_hz, MSSTimerState),
256         VMSTATE_STRUCT_ARRAY(timers, MSSTimerState, NUM_TIMERS, 0,
257                 vmstate_timers, struct Msf2Timer),
258         VMSTATE_END_OF_LIST()
259     }
260 };
261 
262 static Property mss_timer_properties[] = {
263     /* Libero GUI shows 100Mhz as default for clocks */
264     DEFINE_PROP_UINT32("clock-frequency", MSSTimerState, freq_hz,
265                       100 * 1000000),
266     DEFINE_PROP_END_OF_LIST(),
267 };
268 
269 static void mss_timer_class_init(ObjectClass *klass, void *data)
270 {
271     DeviceClass *dc = DEVICE_CLASS(klass);
272 
273     dc->props = mss_timer_properties;
274     dc->vmsd = &vmstate_mss_timer;
275 }
276 
277 static const TypeInfo mss_timer_info = {
278     .name          = TYPE_MSS_TIMER,
279     .parent        = TYPE_SYS_BUS_DEVICE,
280     .instance_size = sizeof(MSSTimerState),
281     .instance_init = mss_timer_init,
282     .class_init    = mss_timer_class_init,
283 };
284 
285 static void mss_timer_register_types(void)
286 {
287     type_register_static(&mss_timer_info);
288 }
289 
290 type_init(mss_timer_register_types)
291