xref: /openbmc/qemu/hw/timer/mss-timer.c (revision f0984d40)
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/module.h"
28 #include "qemu/log.h"
29 #include "hw/irq.h"
30 #include "hw/qdev-properties.h"
31 #include "hw/timer/mss-timer.h"
32 #include "migration/vmstate.h"
33 
34 #ifndef MSS_TIMER_ERR_DEBUG
35 #define MSS_TIMER_ERR_DEBUG  0
36 #endif
37 
38 #define DB_PRINT_L(lvl, fmt, args...) do { \
39     if (MSS_TIMER_ERR_DEBUG >= lvl) { \
40         qemu_log("%s: " fmt "\n", __func__, ## args); \
41     } \
42 } while (0)
43 
44 #define DB_PRINT(fmt, args...) DB_PRINT_L(1, fmt, ## args)
45 
46 #define R_TIM_VAL         0
47 #define R_TIM_LOADVAL     1
48 #define R_TIM_BGLOADVAL   2
49 #define R_TIM_CTRL        3
50 #define R_TIM_RIS         4
51 #define R_TIM_MIS         5
52 
53 #define TIMER_CTRL_ENBL     (1 << 0)
54 #define TIMER_CTRL_ONESHOT  (1 << 1)
55 #define TIMER_CTRL_INTR     (1 << 2)
56 #define TIMER_RIS_ACK       (1 << 0)
57 #define TIMER_RST_CLR       (1 << 6)
58 #define TIMER_MODE          (1 << 0)
59 
60 static void timer_update_irq(struct Msf2Timer *st)
61 {
62     bool isr, ier;
63 
64     isr = !!(st->regs[R_TIM_RIS] & TIMER_RIS_ACK);
65     ier = !!(st->regs[R_TIM_CTRL] & TIMER_CTRL_INTR);
66     qemu_set_irq(st->irq, (ier && isr));
67 }
68 
69 /* Must be called from within a ptimer_transaction_begin/commit block */
70 static void timer_update(struct Msf2Timer *st)
71 {
72     uint64_t count;
73 
74     if (!(st->regs[R_TIM_CTRL] & TIMER_CTRL_ENBL)) {
75         ptimer_stop(st->ptimer);
76         return;
77     }
78 
79     count = st->regs[R_TIM_LOADVAL];
80     ptimer_set_limit(st->ptimer, count, 1);
81     ptimer_run(st->ptimer, 1);
82 }
83 
84 static uint64_t
85 timer_read(void *opaque, hwaddr offset, unsigned int size)
86 {
87     MSSTimerState *t = opaque;
88     hwaddr addr;
89     struct Msf2Timer *st;
90     uint32_t ret = 0;
91     int timer = 0;
92     int isr;
93     int ier;
94 
95     addr = offset >> 2;
96     /*
97      * Two independent timers has same base address.
98      * Based on address passed figure out which timer is being used.
99      */
100     if ((addr >= R_TIM1_MAX) && (addr < NUM_TIMERS * R_TIM1_MAX)) {
101         timer = 1;
102         addr -= R_TIM1_MAX;
103     }
104 
105     st = &t->timers[timer];
106 
107     switch (addr) {
108     case R_TIM_VAL:
109         ret = ptimer_get_count(st->ptimer);
110         break;
111 
112     case R_TIM_MIS:
113         isr = !!(st->regs[R_TIM_RIS] & TIMER_RIS_ACK);
114         ier = !!(st->regs[R_TIM_CTRL] & TIMER_CTRL_INTR);
115         ret = ier & isr;
116         break;
117 
118     default:
119         if (addr < R_TIM1_MAX) {
120             ret = st->regs[addr];
121         } else {
122             qemu_log_mask(LOG_GUEST_ERROR,
123                         TYPE_MSS_TIMER": 64-bit mode not supported\n");
124             return ret;
125         }
126         break;
127     }
128 
129     DB_PRINT("timer=%d 0x%" HWADDR_PRIx "=0x%" PRIx32, timer, offset,
130             ret);
131     return ret;
132 }
133 
134 static void
135 timer_write(void *opaque, hwaddr offset,
136             uint64_t val64, unsigned int size)
137 {
138     MSSTimerState *t = opaque;
139     hwaddr addr;
140     struct Msf2Timer *st;
141     int timer = 0;
142     uint32_t value = val64;
143 
144     addr = offset >> 2;
145     /*
146      * Two independent timers has same base address.
147      * Based on addr passed figure out which timer is being used.
148      */
149     if ((addr >= R_TIM1_MAX) && (addr < NUM_TIMERS * R_TIM1_MAX)) {
150         timer = 1;
151         addr -= R_TIM1_MAX;
152     }
153 
154     st = &t->timers[timer];
155 
156     DB_PRINT("addr=0x%" HWADDR_PRIx " val=0x%" PRIx32 " (timer=%d)", offset,
157             value, timer);
158 
159     switch (addr) {
160     case R_TIM_CTRL:
161         st->regs[R_TIM_CTRL] = value;
162         ptimer_transaction_begin(st->ptimer);
163         timer_update(st);
164         ptimer_transaction_commit(st->ptimer);
165         break;
166 
167     case R_TIM_RIS:
168         if (value & TIMER_RIS_ACK) {
169             st->regs[R_TIM_RIS] &= ~TIMER_RIS_ACK;
170         }
171         break;
172 
173     case R_TIM_LOADVAL:
174         st->regs[R_TIM_LOADVAL] = value;
175         if (st->regs[R_TIM_CTRL] & TIMER_CTRL_ENBL) {
176             ptimer_transaction_begin(st->ptimer);
177             timer_update(st);
178             ptimer_transaction_commit(st->ptimer);
179         }
180         break;
181 
182     case R_TIM_BGLOADVAL:
183         st->regs[R_TIM_BGLOADVAL] = value;
184         st->regs[R_TIM_LOADVAL] = value;
185         break;
186 
187     case R_TIM_VAL:
188     case R_TIM_MIS:
189         break;
190 
191     default:
192         if (addr < R_TIM1_MAX) {
193             st->regs[addr] = value;
194         } else {
195             qemu_log_mask(LOG_GUEST_ERROR,
196                         TYPE_MSS_TIMER": 64-bit mode not supported\n");
197             return;
198         }
199         break;
200     }
201     timer_update_irq(st);
202 }
203 
204 static const MemoryRegionOps timer_ops = {
205     .read = timer_read,
206     .write = timer_write,
207     .endianness = DEVICE_NATIVE_ENDIAN,
208     .valid = {
209         .min_access_size = 1,
210         .max_access_size = 4
211     }
212 };
213 
214 static void timer_hit(void *opaque)
215 {
216     struct Msf2Timer *st = opaque;
217 
218     st->regs[R_TIM_RIS] |= TIMER_RIS_ACK;
219 
220     if (!(st->regs[R_TIM_CTRL] & TIMER_CTRL_ONESHOT)) {
221         timer_update(st);
222     }
223     timer_update_irq(st);
224 }
225 
226 static void mss_timer_init(Object *obj)
227 {
228     MSSTimerState *t = MSS_TIMER(obj);
229     int i;
230 
231     /* Init all the ptimers.  */
232     for (i = 0; i < NUM_TIMERS; i++) {
233         struct Msf2Timer *st = &t->timers[i];
234 
235         st->ptimer = ptimer_init(timer_hit, st, PTIMER_POLICY_LEGACY);
236         ptimer_transaction_begin(st->ptimer);
237         ptimer_set_freq(st->ptimer, t->freq_hz);
238         ptimer_transaction_commit(st->ptimer);
239         sysbus_init_irq(SYS_BUS_DEVICE(obj), &st->irq);
240     }
241 
242     memory_region_init_io(&t->mmio, OBJECT(t), &timer_ops, t, TYPE_MSS_TIMER,
243                           NUM_TIMERS * R_TIM1_MAX * 4);
244     sysbus_init_mmio(SYS_BUS_DEVICE(obj), &t->mmio);
245 }
246 
247 static void mss_timer_finalize(Object *obj)
248 {
249     MSSTimerState *t = MSS_TIMER(obj);
250     int i;
251 
252     for (i = 0; i < NUM_TIMERS; i++) {
253         struct Msf2Timer *st = &t->timers[i];
254 
255         ptimer_free(st->ptimer);
256     }
257 }
258 
259 static const VMStateDescription vmstate_timers = {
260     .name = "mss-timer-block",
261     .version_id = 1,
262     .minimum_version_id = 1,
263     .fields = (VMStateField[]) {
264         VMSTATE_PTIMER(ptimer, struct Msf2Timer),
265         VMSTATE_UINT32_ARRAY(regs, struct Msf2Timer, R_TIM1_MAX),
266         VMSTATE_END_OF_LIST()
267     }
268 };
269 
270 static const VMStateDescription vmstate_mss_timer = {
271     .name = TYPE_MSS_TIMER,
272     .version_id = 1,
273     .minimum_version_id = 1,
274     .fields = (VMStateField[]) {
275         VMSTATE_UINT32(freq_hz, MSSTimerState),
276         VMSTATE_STRUCT_ARRAY(timers, MSSTimerState, NUM_TIMERS, 0,
277                 vmstate_timers, struct Msf2Timer),
278         VMSTATE_END_OF_LIST()
279     }
280 };
281 
282 static Property mss_timer_properties[] = {
283     /* Libero GUI shows 100Mhz as default for clocks */
284     DEFINE_PROP_UINT32("clock-frequency", MSSTimerState, freq_hz,
285                       100 * 1000000),
286     DEFINE_PROP_END_OF_LIST(),
287 };
288 
289 static void mss_timer_class_init(ObjectClass *klass, void *data)
290 {
291     DeviceClass *dc = DEVICE_CLASS(klass);
292 
293     device_class_set_props(dc, mss_timer_properties);
294     dc->vmsd = &vmstate_mss_timer;
295 }
296 
297 static const TypeInfo mss_timer_info = {
298     .name          = TYPE_MSS_TIMER,
299     .parent        = TYPE_SYS_BUS_DEVICE,
300     .instance_size = sizeof(MSSTimerState),
301     .instance_init = mss_timer_init,
302     .instance_finalize = mss_timer_finalize,
303     .class_init    = mss_timer_class_init,
304 };
305 
306 static void mss_timer_register_types(void)
307 {
308     type_register_static(&mss_timer_info);
309 }
310 
311 type_init(mss_timer_register_types)
312