xref: /openbmc/qemu/hw/timer/mss-timer.c (revision 750541c4)
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/log.h"
29 #include "hw/timer/mss-timer.h"
30 
31 #ifndef MSS_TIMER_ERR_DEBUG
32 #define MSS_TIMER_ERR_DEBUG  0
33 #endif
34 
35 #define DB_PRINT_L(lvl, fmt, args...) do { \
36     if (MSS_TIMER_ERR_DEBUG >= lvl) { \
37         qemu_log("%s: " fmt "\n", __func__, ## args); \
38     } \
39 } while (0)
40 
41 #define DB_PRINT(fmt, args...) DB_PRINT_L(1, fmt, ## args)
42 
43 #define R_TIM_VAL         0
44 #define R_TIM_LOADVAL     1
45 #define R_TIM_BGLOADVAL   2
46 #define R_TIM_CTRL        3
47 #define R_TIM_RIS         4
48 #define R_TIM_MIS         5
49 
50 #define TIMER_CTRL_ENBL     (1 << 0)
51 #define TIMER_CTRL_ONESHOT  (1 << 1)
52 #define TIMER_CTRL_INTR     (1 << 2)
53 #define TIMER_RIS_ACK       (1 << 0)
54 #define TIMER_RST_CLR       (1 << 6)
55 #define TIMER_MODE          (1 << 0)
56 
57 static void timer_update_irq(struct Msf2Timer *st)
58 {
59     bool isr, ier;
60 
61     isr = !!(st->regs[R_TIM_RIS] & TIMER_RIS_ACK);
62     ier = !!(st->regs[R_TIM_CTRL] & TIMER_CTRL_INTR);
63     qemu_set_irq(st->irq, (ier && isr));
64 }
65 
66 static void timer_update(struct Msf2Timer *st)
67 {
68     uint64_t count;
69 
70     if (!(st->regs[R_TIM_CTRL] & TIMER_CTRL_ENBL)) {
71         ptimer_stop(st->ptimer);
72         return;
73     }
74 
75     count = st->regs[R_TIM_LOADVAL];
76     ptimer_set_limit(st->ptimer, count, 1);
77     ptimer_run(st->ptimer, 1);
78 }
79 
80 static uint64_t
81 timer_read(void *opaque, hwaddr offset, unsigned int size)
82 {
83     MSSTimerState *t = opaque;
84     hwaddr addr;
85     struct Msf2Timer *st;
86     uint32_t ret = 0;
87     int timer = 0;
88     int isr;
89     int ier;
90 
91     addr = offset >> 2;
92     /*
93      * Two independent timers has same base address.
94      * Based on address passed figure out which timer is being used.
95      */
96     if ((addr >= R_TIM1_MAX) && (addr < NUM_TIMERS * R_TIM1_MAX)) {
97         timer = 1;
98         addr -= R_TIM1_MAX;
99     }
100 
101     st = &t->timers[timer];
102 
103     switch (addr) {
104     case R_TIM_VAL:
105         ret = ptimer_get_count(st->ptimer);
106         break;
107 
108     case R_TIM_MIS:
109         isr = !!(st->regs[R_TIM_RIS] & TIMER_RIS_ACK);
110         ier = !!(st->regs[R_TIM_CTRL] & TIMER_CTRL_INTR);
111         ret = ier & isr;
112         break;
113 
114     default:
115         if (addr < R_TIM1_MAX) {
116             ret = st->regs[addr];
117         } else {
118             qemu_log_mask(LOG_GUEST_ERROR,
119                         TYPE_MSS_TIMER": 64-bit mode not supported\n");
120             return ret;
121         }
122         break;
123     }
124 
125     DB_PRINT("timer=%d 0x%" HWADDR_PRIx "=0x%" PRIx32, timer, offset,
126             ret);
127     return ret;
128 }
129 
130 static void
131 timer_write(void *opaque, hwaddr offset,
132             uint64_t val64, unsigned int size)
133 {
134     MSSTimerState *t = opaque;
135     hwaddr addr;
136     struct Msf2Timer *st;
137     int timer = 0;
138     uint32_t value = val64;
139 
140     addr = offset >> 2;
141     /*
142      * Two independent timers has same base address.
143      * Based on addr passed figure out which timer is being used.
144      */
145     if ((addr >= R_TIM1_MAX) && (addr < NUM_TIMERS * R_TIM1_MAX)) {
146         timer = 1;
147         addr -= R_TIM1_MAX;
148     }
149 
150     st = &t->timers[timer];
151 
152     DB_PRINT("addr=0x%" HWADDR_PRIx " val=0x%" PRIx32 " (timer=%d)", offset,
153             value, timer);
154 
155     switch (addr) {
156     case R_TIM_CTRL:
157         st->regs[R_TIM_CTRL] = value;
158         timer_update(st);
159         break;
160 
161     case R_TIM_RIS:
162         if (value & TIMER_RIS_ACK) {
163             st->regs[R_TIM_RIS] &= ~TIMER_RIS_ACK;
164         }
165         break;
166 
167     case R_TIM_LOADVAL:
168         st->regs[R_TIM_LOADVAL] = value;
169         if (st->regs[R_TIM_CTRL] & TIMER_CTRL_ENBL) {
170             timer_update(st);
171         }
172         break;
173 
174     case R_TIM_BGLOADVAL:
175         st->regs[R_TIM_BGLOADVAL] = value;
176         st->regs[R_TIM_LOADVAL] = value;
177         break;
178 
179     case R_TIM_VAL:
180     case R_TIM_MIS:
181         break;
182 
183     default:
184         if (addr < R_TIM1_MAX) {
185             st->regs[addr] = value;
186         } else {
187             qemu_log_mask(LOG_GUEST_ERROR,
188                         TYPE_MSS_TIMER": 64-bit mode not supported\n");
189             return;
190         }
191         break;
192     }
193     timer_update_irq(st);
194 }
195 
196 static const MemoryRegionOps timer_ops = {
197     .read = timer_read,
198     .write = timer_write,
199     .endianness = DEVICE_NATIVE_ENDIAN,
200     .valid = {
201         .min_access_size = 1,
202         .max_access_size = 4
203     }
204 };
205 
206 static void timer_hit(void *opaque)
207 {
208     struct Msf2Timer *st = opaque;
209 
210     st->regs[R_TIM_RIS] |= TIMER_RIS_ACK;
211 
212     if (!(st->regs[R_TIM_CTRL] & TIMER_CTRL_ONESHOT)) {
213         timer_update(st);
214     }
215     timer_update_irq(st);
216 }
217 
218 static void mss_timer_init(Object *obj)
219 {
220     MSSTimerState *t = MSS_TIMER(obj);
221     int i;
222 
223     /* Init all the ptimers.  */
224     for (i = 0; i < NUM_TIMERS; i++) {
225         struct Msf2Timer *st = &t->timers[i];
226 
227         st->bh = qemu_bh_new(timer_hit, st);
228         st->ptimer = ptimer_init(st->bh, PTIMER_POLICY_DEFAULT);
229         ptimer_set_freq(st->ptimer, t->freq_hz);
230         sysbus_init_irq(SYS_BUS_DEVICE(obj), &st->irq);
231     }
232 
233     memory_region_init_io(&t->mmio, OBJECT(t), &timer_ops, t, TYPE_MSS_TIMER,
234                           NUM_TIMERS * R_TIM1_MAX * 4);
235     sysbus_init_mmio(SYS_BUS_DEVICE(obj), &t->mmio);
236 }
237 
238 static const VMStateDescription vmstate_timers = {
239     .name = "mss-timer-block",
240     .version_id = 1,
241     .minimum_version_id = 1,
242     .fields = (VMStateField[]) {
243         VMSTATE_PTIMER(ptimer, struct Msf2Timer),
244         VMSTATE_UINT32_ARRAY(regs, struct Msf2Timer, R_TIM1_MAX),
245         VMSTATE_END_OF_LIST()
246     }
247 };
248 
249 static const VMStateDescription vmstate_mss_timer = {
250     .name = TYPE_MSS_TIMER,
251     .version_id = 1,
252     .minimum_version_id = 1,
253     .fields = (VMStateField[]) {
254         VMSTATE_UINT32(freq_hz, MSSTimerState),
255         VMSTATE_STRUCT_ARRAY(timers, MSSTimerState, NUM_TIMERS, 0,
256                 vmstate_timers, struct Msf2Timer),
257         VMSTATE_END_OF_LIST()
258     }
259 };
260 
261 static Property mss_timer_properties[] = {
262     /* Libero GUI shows 100Mhz as default for clocks */
263     DEFINE_PROP_UINT32("clock-frequency", MSSTimerState, freq_hz,
264                       100 * 1000000),
265     DEFINE_PROP_END_OF_LIST(),
266 };
267 
268 static void mss_timer_class_init(ObjectClass *klass, void *data)
269 {
270     DeviceClass *dc = DEVICE_CLASS(klass);
271 
272     dc->props = mss_timer_properties;
273     dc->vmsd = &vmstate_mss_timer;
274 }
275 
276 static const TypeInfo mss_timer_info = {
277     .name          = TYPE_MSS_TIMER,
278     .parent        = TYPE_SYS_BUS_DEVICE,
279     .instance_size = sizeof(MSSTimerState),
280     .instance_init = mss_timer_init,
281     .class_init    = mss_timer_class_init,
282 };
283 
284 static void mss_timer_register_types(void)
285 {
286     type_register_static(&mss_timer_info);
287 }
288 
289 type_init(mss_timer_register_types)
290