xref: /openbmc/qemu/hw/timer/etraxfs_timer.c (revision effd60c8)
1 /*
2  * QEMU ETRAX Timers
3  *
4  * Copyright (c) 2007 Edgar E. Iglesias, Axis Communications AB.
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/sysbus.h"
27 #include "sysemu/reset.h"
28 #include "sysemu/runstate.h"
29 #include "migration/vmstate.h"
30 #include "qemu/module.h"
31 #include "qemu/timer.h"
32 #include "hw/irq.h"
33 #include "hw/ptimer.h"
34 #include "qom/object.h"
35 
36 #define D(x)
37 
38 #define RW_TMR0_DIV   0x00
39 #define R_TMR0_DATA   0x04
40 #define RW_TMR0_CTRL  0x08
41 #define RW_TMR1_DIV   0x10
42 #define R_TMR1_DATA   0x14
43 #define RW_TMR1_CTRL  0x18
44 #define R_TIME        0x38
45 #define RW_WD_CTRL    0x40
46 #define R_WD_STAT     0x44
47 #define RW_INTR_MASK  0x48
48 #define RW_ACK_INTR   0x4c
49 #define R_INTR        0x50
50 #define R_MASKED_INTR 0x54
51 
52 #define TYPE_ETRAX_FS_TIMER "etraxfs-timer"
53 typedef struct ETRAXTimerState ETRAXTimerState;
54 DECLARE_INSTANCE_CHECKER(ETRAXTimerState, ETRAX_TIMER,
55                          TYPE_ETRAX_FS_TIMER)
56 
57 struct ETRAXTimerState {
58     SysBusDevice parent_obj;
59 
60     MemoryRegion mmio;
61     qemu_irq irq;
62     qemu_irq nmi;
63 
64     ptimer_state *ptimer_t0;
65     ptimer_state *ptimer_t1;
66     ptimer_state *ptimer_wd;
67 
68     uint32_t wd_hits;
69 
70     /* Control registers.  */
71     uint32_t rw_tmr0_div;
72     uint32_t r_tmr0_data;
73     uint32_t rw_tmr0_ctrl;
74 
75     uint32_t rw_tmr1_div;
76     uint32_t r_tmr1_data;
77     uint32_t rw_tmr1_ctrl;
78 
79     uint32_t rw_wd_ctrl;
80 
81     uint32_t rw_intr_mask;
82     uint32_t rw_ack_intr;
83     uint32_t r_intr;
84     uint32_t r_masked_intr;
85 };
86 
87 static const VMStateDescription vmstate_etraxfs = {
88     .name = "etraxfs",
89     .version_id = 0,
90     .minimum_version_id = 0,
91     .fields = (const VMStateField[]) {
92         VMSTATE_PTIMER(ptimer_t0, ETRAXTimerState),
93         VMSTATE_PTIMER(ptimer_t1, ETRAXTimerState),
94         VMSTATE_PTIMER(ptimer_wd, ETRAXTimerState),
95 
96         VMSTATE_UINT32(wd_hits, ETRAXTimerState),
97 
98         VMSTATE_UINT32(rw_tmr0_div, ETRAXTimerState),
99         VMSTATE_UINT32(r_tmr0_data, ETRAXTimerState),
100         VMSTATE_UINT32(rw_tmr0_ctrl, ETRAXTimerState),
101 
102         VMSTATE_UINT32(rw_tmr1_div, ETRAXTimerState),
103         VMSTATE_UINT32(r_tmr1_data, ETRAXTimerState),
104         VMSTATE_UINT32(rw_tmr1_ctrl, ETRAXTimerState),
105 
106         VMSTATE_UINT32(rw_wd_ctrl, ETRAXTimerState),
107 
108         VMSTATE_UINT32(rw_intr_mask, ETRAXTimerState),
109         VMSTATE_UINT32(rw_ack_intr, ETRAXTimerState),
110         VMSTATE_UINT32(r_intr, ETRAXTimerState),
111         VMSTATE_UINT32(r_masked_intr, ETRAXTimerState),
112 
113         VMSTATE_END_OF_LIST()
114     }
115 };
116 
117 static uint64_t
118 timer_read(void *opaque, hwaddr addr, unsigned int size)
119 {
120     ETRAXTimerState *t = opaque;
121     uint32_t r = 0;
122 
123     switch (addr) {
124     case R_TMR0_DATA:
125         r = ptimer_get_count(t->ptimer_t0);
126         break;
127     case R_TMR1_DATA:
128         r = ptimer_get_count(t->ptimer_t1);
129         break;
130     case R_TIME:
131         r = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) / 10;
132         break;
133     case RW_INTR_MASK:
134         r = t->rw_intr_mask;
135         break;
136     case R_MASKED_INTR:
137         r = t->r_intr & t->rw_intr_mask;
138         break;
139     default:
140         D(printf ("%s %x\n", __func__, addr));
141         break;
142     }
143     return r;
144 }
145 
146 static void update_ctrl(ETRAXTimerState *t, int tnum)
147 {
148     unsigned int op;
149     unsigned int freq;
150     unsigned int freq_hz;
151     unsigned int div;
152     uint32_t ctrl;
153 
154     ptimer_state *timer;
155 
156     if (tnum == 0) {
157         ctrl = t->rw_tmr0_ctrl;
158         div = t->rw_tmr0_div;
159         timer = t->ptimer_t0;
160     } else {
161         ctrl = t->rw_tmr1_ctrl;
162         div = t->rw_tmr1_div;
163         timer = t->ptimer_t1;
164     }
165 
166 
167     op = ctrl & 3;
168     freq = ctrl >> 2;
169     freq_hz = 32000000;
170 
171     switch (freq)
172     {
173     case 0:
174     case 1:
175         D(printf ("extern or disabled timer clock?\n"));
176         break;
177     case 4: freq_hz =  29493000; break;
178     case 5: freq_hz =  32000000; break;
179     case 6: freq_hz =  32768000; break;
180     case 7: freq_hz = 100000000; break;
181     default:
182         abort();
183         break;
184     }
185 
186     D(printf ("freq_hz=%d div=%d\n", freq_hz, div));
187     ptimer_transaction_begin(timer);
188     ptimer_set_freq(timer, freq_hz);
189     ptimer_set_limit(timer, div, 0);
190 
191     switch (op)
192     {
193         case 0:
194             /* Load.  */
195             ptimer_set_limit(timer, div, 1);
196             break;
197         case 1:
198             /* Hold.  */
199             ptimer_stop(timer);
200             break;
201         case 2:
202             /* Run.  */
203             ptimer_run(timer, 0);
204             break;
205         default:
206             abort();
207             break;
208     }
209     ptimer_transaction_commit(timer);
210 }
211 
212 static void timer_update_irq(ETRAXTimerState *t)
213 {
214     t->r_intr &= ~(t->rw_ack_intr);
215     t->r_masked_intr = t->r_intr & t->rw_intr_mask;
216 
217     D(printf("%s: masked_intr=%x\n", __func__, t->r_masked_intr));
218     qemu_set_irq(t->irq, !!t->r_masked_intr);
219 }
220 
221 static void timer0_hit(void *opaque)
222 {
223     ETRAXTimerState *t = opaque;
224     t->r_intr |= 1;
225     timer_update_irq(t);
226 }
227 
228 static void timer1_hit(void *opaque)
229 {
230     ETRAXTimerState *t = opaque;
231     t->r_intr |= 2;
232     timer_update_irq(t);
233 }
234 
235 static void watchdog_hit(void *opaque)
236 {
237     ETRAXTimerState *t = opaque;
238     if (t->wd_hits == 0) {
239         /* real hw gives a single tick before resetting but we are
240            a bit friendlier to compensate for our slower execution.  */
241         ptimer_set_count(t->ptimer_wd, 10);
242         ptimer_run(t->ptimer_wd, 1);
243         qemu_irq_raise(t->nmi);
244     }
245     else
246         qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
247 
248     t->wd_hits++;
249 }
250 
251 static inline void timer_watchdog_update(ETRAXTimerState *t, uint32_t value)
252 {
253     unsigned int wd_en = t->rw_wd_ctrl & (1 << 8);
254     unsigned int wd_key = t->rw_wd_ctrl >> 9;
255     unsigned int wd_cnt = t->rw_wd_ctrl & 511;
256     unsigned int new_key = value >> 9 & ((1 << 7) - 1);
257     unsigned int new_cmd = (value >> 8) & 1;
258 
259     /* If the watchdog is enabled, they written key must match the
260        complement of the previous.  */
261     wd_key = ~wd_key & ((1 << 7) - 1);
262 
263     if (wd_en && wd_key != new_key)
264         return;
265 
266     D(printf("en=%d new_key=%x oldkey=%x cmd=%d cnt=%d\n",
267          wd_en, new_key, wd_key, new_cmd, wd_cnt));
268 
269     if (t->wd_hits)
270         qemu_irq_lower(t->nmi);
271 
272     t->wd_hits = 0;
273 
274     ptimer_transaction_begin(t->ptimer_wd);
275     ptimer_set_freq(t->ptimer_wd, 760);
276     if (wd_cnt == 0)
277         wd_cnt = 256;
278     ptimer_set_count(t->ptimer_wd, wd_cnt);
279     if (new_cmd)
280         ptimer_run(t->ptimer_wd, 1);
281     else
282         ptimer_stop(t->ptimer_wd);
283 
284     t->rw_wd_ctrl = value;
285     ptimer_transaction_commit(t->ptimer_wd);
286 }
287 
288 static void
289 timer_write(void *opaque, hwaddr addr,
290             uint64_t val64, unsigned int size)
291 {
292     ETRAXTimerState *t = opaque;
293     uint32_t value = val64;
294 
295     switch (addr)
296     {
297         case RW_TMR0_DIV:
298             t->rw_tmr0_div = value;
299             break;
300         case RW_TMR0_CTRL:
301             D(printf ("RW_TMR0_CTRL=%x\n", value));
302             t->rw_tmr0_ctrl = value;
303             update_ctrl(t, 0);
304             break;
305         case RW_TMR1_DIV:
306             t->rw_tmr1_div = value;
307             break;
308         case RW_TMR1_CTRL:
309             D(printf ("RW_TMR1_CTRL=%x\n", value));
310             t->rw_tmr1_ctrl = value;
311             update_ctrl(t, 1);
312             break;
313         case RW_INTR_MASK:
314             D(printf ("RW_INTR_MASK=%x\n", value));
315             t->rw_intr_mask = value;
316             timer_update_irq(t);
317             break;
318         case RW_WD_CTRL:
319             timer_watchdog_update(t, value);
320             break;
321         case RW_ACK_INTR:
322             t->rw_ack_intr = value;
323             timer_update_irq(t);
324             t->rw_ack_intr = 0;
325             break;
326         default:
327             printf("%s " HWADDR_FMT_plx " %x\n", __func__, addr, value);
328             break;
329     }
330 }
331 
332 static const MemoryRegionOps timer_ops = {
333     .read = timer_read,
334     .write = timer_write,
335     .endianness = DEVICE_LITTLE_ENDIAN,
336     .valid = {
337         .min_access_size = 4,
338         .max_access_size = 4
339     }
340 };
341 
342 static void etraxfs_timer_reset_enter(Object *obj, ResetType type)
343 {
344     ETRAXTimerState *t = ETRAX_TIMER(obj);
345 
346     ptimer_transaction_begin(t->ptimer_t0);
347     ptimer_stop(t->ptimer_t0);
348     ptimer_transaction_commit(t->ptimer_t0);
349     ptimer_transaction_begin(t->ptimer_t1);
350     ptimer_stop(t->ptimer_t1);
351     ptimer_transaction_commit(t->ptimer_t1);
352     ptimer_transaction_begin(t->ptimer_wd);
353     ptimer_stop(t->ptimer_wd);
354     ptimer_transaction_commit(t->ptimer_wd);
355     t->rw_wd_ctrl = 0;
356     t->r_intr = 0;
357     t->rw_intr_mask = 0;
358 }
359 
360 static void etraxfs_timer_reset_hold(Object *obj)
361 {
362     ETRAXTimerState *t = ETRAX_TIMER(obj);
363 
364     qemu_irq_lower(t->irq);
365 }
366 
367 static void etraxfs_timer_realize(DeviceState *dev, Error **errp)
368 {
369     ETRAXTimerState *t = ETRAX_TIMER(dev);
370     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
371 
372     t->ptimer_t0 = ptimer_init(timer0_hit, t, PTIMER_POLICY_LEGACY);
373     t->ptimer_t1 = ptimer_init(timer1_hit, t, PTIMER_POLICY_LEGACY);
374     t->ptimer_wd = ptimer_init(watchdog_hit, t, PTIMER_POLICY_LEGACY);
375 
376     sysbus_init_irq(sbd, &t->irq);
377     sysbus_init_irq(sbd, &t->nmi);
378 
379     memory_region_init_io(&t->mmio, OBJECT(t), &timer_ops, t,
380                           "etraxfs-timer", 0x5c);
381     sysbus_init_mmio(sbd, &t->mmio);
382 }
383 
384 static void etraxfs_timer_class_init(ObjectClass *klass, void *data)
385 {
386     DeviceClass *dc = DEVICE_CLASS(klass);
387     ResettableClass *rc = RESETTABLE_CLASS(klass);
388 
389     dc->realize = etraxfs_timer_realize;
390     dc->vmsd = &vmstate_etraxfs;
391     rc->phases.enter = etraxfs_timer_reset_enter;
392     rc->phases.hold = etraxfs_timer_reset_hold;
393 }
394 
395 static const TypeInfo etraxfs_timer_info = {
396     .name          = TYPE_ETRAX_FS_TIMER,
397     .parent        = TYPE_SYS_BUS_DEVICE,
398     .instance_size = sizeof(ETRAXTimerState),
399     .class_init    = etraxfs_timer_class_init,
400 };
401 
402 static void etraxfs_timer_register_types(void)
403 {
404     type_register_static(&etraxfs_timer_info);
405 }
406 
407 type_init(etraxfs_timer_register_types)
408