xref: /openbmc/qemu/hw/timer/etraxfs_timer.c (revision 20a4f14f)
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 "qemu/module.h"
30 #include "qemu/timer.h"
31 #include "hw/irq.h"
32 #include "hw/ptimer.h"
33 
34 #define D(x)
35 
36 #define RW_TMR0_DIV   0x00
37 #define R_TMR0_DATA   0x04
38 #define RW_TMR0_CTRL  0x08
39 #define RW_TMR1_DIV   0x10
40 #define R_TMR1_DATA   0x14
41 #define RW_TMR1_CTRL  0x18
42 #define R_TIME        0x38
43 #define RW_WD_CTRL    0x40
44 #define R_WD_STAT     0x44
45 #define RW_INTR_MASK  0x48
46 #define RW_ACK_INTR   0x4c
47 #define R_INTR        0x50
48 #define R_MASKED_INTR 0x54
49 
50 #define TYPE_ETRAX_FS_TIMER "etraxfs,timer"
51 #define ETRAX_TIMER(obj) \
52     OBJECT_CHECK(ETRAXTimerState, (obj), TYPE_ETRAX_FS_TIMER)
53 
54 typedef struct ETRAXTimerState {
55     SysBusDevice parent_obj;
56 
57     MemoryRegion mmio;
58     qemu_irq irq;
59     qemu_irq nmi;
60 
61     ptimer_state *ptimer_t0;
62     ptimer_state *ptimer_t1;
63     ptimer_state *ptimer_wd;
64 
65     int wd_hits;
66 
67     /* Control registers.  */
68     uint32_t rw_tmr0_div;
69     uint32_t r_tmr0_data;
70     uint32_t rw_tmr0_ctrl;
71 
72     uint32_t rw_tmr1_div;
73     uint32_t r_tmr1_data;
74     uint32_t rw_tmr1_ctrl;
75 
76     uint32_t rw_wd_ctrl;
77 
78     uint32_t rw_intr_mask;
79     uint32_t rw_ack_intr;
80     uint32_t r_intr;
81     uint32_t r_masked_intr;
82 } ETRAXTimerState;
83 
84 static uint64_t
85 timer_read(void *opaque, hwaddr addr, unsigned int size)
86 {
87     ETRAXTimerState *t = opaque;
88     uint32_t r = 0;
89 
90     switch (addr) {
91     case R_TMR0_DATA:
92         r = ptimer_get_count(t->ptimer_t0);
93         break;
94     case R_TMR1_DATA:
95         r = ptimer_get_count(t->ptimer_t1);
96         break;
97     case R_TIME:
98         r = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) / 10;
99         break;
100     case RW_INTR_MASK:
101         r = t->rw_intr_mask;
102         break;
103     case R_MASKED_INTR:
104         r = t->r_intr & t->rw_intr_mask;
105         break;
106     default:
107         D(printf ("%s %x\n", __func__, addr));
108         break;
109     }
110     return r;
111 }
112 
113 static void update_ctrl(ETRAXTimerState *t, int tnum)
114 {
115     unsigned int op;
116     unsigned int freq;
117     unsigned int freq_hz;
118     unsigned int div;
119     uint32_t ctrl;
120 
121     ptimer_state *timer;
122 
123     if (tnum == 0) {
124         ctrl = t->rw_tmr0_ctrl;
125         div = t->rw_tmr0_div;
126         timer = t->ptimer_t0;
127     } else {
128         ctrl = t->rw_tmr1_ctrl;
129         div = t->rw_tmr1_div;
130         timer = t->ptimer_t1;
131     }
132 
133 
134     op = ctrl & 3;
135     freq = ctrl >> 2;
136     freq_hz = 32000000;
137 
138     switch (freq)
139     {
140     case 0:
141     case 1:
142         D(printf ("extern or disabled timer clock?\n"));
143         break;
144     case 4: freq_hz =  29493000; break;
145     case 5: freq_hz =  32000000; break;
146     case 6: freq_hz =  32768000; break;
147     case 7: freq_hz = 100000000; break;
148     default:
149         abort();
150         break;
151     }
152 
153     D(printf ("freq_hz=%d div=%d\n", freq_hz, div));
154     ptimer_transaction_begin(timer);
155     ptimer_set_freq(timer, freq_hz);
156     ptimer_set_limit(timer, div, 0);
157 
158     switch (op)
159     {
160         case 0:
161             /* Load.  */
162             ptimer_set_limit(timer, div, 1);
163             break;
164         case 1:
165             /* Hold.  */
166             ptimer_stop(timer);
167             break;
168         case 2:
169             /* Run.  */
170             ptimer_run(timer, 0);
171             break;
172         default:
173             abort();
174             break;
175     }
176     ptimer_transaction_commit(timer);
177 }
178 
179 static void timer_update_irq(ETRAXTimerState *t)
180 {
181     t->r_intr &= ~(t->rw_ack_intr);
182     t->r_masked_intr = t->r_intr & t->rw_intr_mask;
183 
184     D(printf("%s: masked_intr=%x\n", __func__, t->r_masked_intr));
185     qemu_set_irq(t->irq, !!t->r_masked_intr);
186 }
187 
188 static void timer0_hit(void *opaque)
189 {
190     ETRAXTimerState *t = opaque;
191     t->r_intr |= 1;
192     timer_update_irq(t);
193 }
194 
195 static void timer1_hit(void *opaque)
196 {
197     ETRAXTimerState *t = opaque;
198     t->r_intr |= 2;
199     timer_update_irq(t);
200 }
201 
202 static void watchdog_hit(void *opaque)
203 {
204     ETRAXTimerState *t = opaque;
205     if (t->wd_hits == 0) {
206         /* real hw gives a single tick before reseting but we are
207            a bit friendlier to compensate for our slower execution.  */
208         ptimer_set_count(t->ptimer_wd, 10);
209         ptimer_run(t->ptimer_wd, 1);
210         qemu_irq_raise(t->nmi);
211     }
212     else
213         qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
214 
215     t->wd_hits++;
216 }
217 
218 static inline void timer_watchdog_update(ETRAXTimerState *t, uint32_t value)
219 {
220     unsigned int wd_en = t->rw_wd_ctrl & (1 << 8);
221     unsigned int wd_key = t->rw_wd_ctrl >> 9;
222     unsigned int wd_cnt = t->rw_wd_ctrl & 511;
223     unsigned int new_key = value >> 9 & ((1 << 7) - 1);
224     unsigned int new_cmd = (value >> 8) & 1;
225 
226     /* If the watchdog is enabled, they written key must match the
227        complement of the previous.  */
228     wd_key = ~wd_key & ((1 << 7) - 1);
229 
230     if (wd_en && wd_key != new_key)
231         return;
232 
233     D(printf("en=%d new_key=%x oldkey=%x cmd=%d cnt=%d\n",
234          wd_en, new_key, wd_key, new_cmd, wd_cnt));
235 
236     if (t->wd_hits)
237         qemu_irq_lower(t->nmi);
238 
239     t->wd_hits = 0;
240 
241     ptimer_transaction_begin(t->ptimer_wd);
242     ptimer_set_freq(t->ptimer_wd, 760);
243     if (wd_cnt == 0)
244         wd_cnt = 256;
245     ptimer_set_count(t->ptimer_wd, wd_cnt);
246     if (new_cmd)
247         ptimer_run(t->ptimer_wd, 1);
248     else
249         ptimer_stop(t->ptimer_wd);
250 
251     t->rw_wd_ctrl = value;
252     ptimer_transaction_commit(t->ptimer_wd);
253 }
254 
255 static void
256 timer_write(void *opaque, hwaddr addr,
257             uint64_t val64, unsigned int size)
258 {
259     ETRAXTimerState *t = opaque;
260     uint32_t value = val64;
261 
262     switch (addr)
263     {
264         case RW_TMR0_DIV:
265             t->rw_tmr0_div = value;
266             break;
267         case RW_TMR0_CTRL:
268             D(printf ("RW_TMR0_CTRL=%x\n", value));
269             t->rw_tmr0_ctrl = value;
270             update_ctrl(t, 0);
271             break;
272         case RW_TMR1_DIV:
273             t->rw_tmr1_div = value;
274             break;
275         case RW_TMR1_CTRL:
276             D(printf ("RW_TMR1_CTRL=%x\n", value));
277             t->rw_tmr1_ctrl = value;
278             update_ctrl(t, 1);
279             break;
280         case RW_INTR_MASK:
281             D(printf ("RW_INTR_MASK=%x\n", value));
282             t->rw_intr_mask = value;
283             timer_update_irq(t);
284             break;
285         case RW_WD_CTRL:
286             timer_watchdog_update(t, value);
287             break;
288         case RW_ACK_INTR:
289             t->rw_ack_intr = value;
290             timer_update_irq(t);
291             t->rw_ack_intr = 0;
292             break;
293         default:
294             printf ("%s " TARGET_FMT_plx " %x\n",
295                 __func__, addr, value);
296             break;
297     }
298 }
299 
300 static const MemoryRegionOps timer_ops = {
301     .read = timer_read,
302     .write = timer_write,
303     .endianness = DEVICE_LITTLE_ENDIAN,
304     .valid = {
305         .min_access_size = 4,
306         .max_access_size = 4
307     }
308 };
309 
310 static void etraxfs_timer_reset(void *opaque)
311 {
312     ETRAXTimerState *t = opaque;
313 
314     ptimer_transaction_begin(t->ptimer_t0);
315     ptimer_stop(t->ptimer_t0);
316     ptimer_transaction_commit(t->ptimer_t0);
317     ptimer_transaction_begin(t->ptimer_t1);
318     ptimer_stop(t->ptimer_t1);
319     ptimer_transaction_commit(t->ptimer_t1);
320     ptimer_transaction_begin(t->ptimer_wd);
321     ptimer_stop(t->ptimer_wd);
322     ptimer_transaction_commit(t->ptimer_wd);
323     t->rw_wd_ctrl = 0;
324     t->r_intr = 0;
325     t->rw_intr_mask = 0;
326     qemu_irq_lower(t->irq);
327 }
328 
329 static void etraxfs_timer_realize(DeviceState *dev, Error **errp)
330 {
331     ETRAXTimerState *t = ETRAX_TIMER(dev);
332     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
333 
334     t->ptimer_t0 = ptimer_init(timer0_hit, t, PTIMER_POLICY_DEFAULT);
335     t->ptimer_t1 = ptimer_init(timer1_hit, t, PTIMER_POLICY_DEFAULT);
336     t->ptimer_wd = ptimer_init(watchdog_hit, t, PTIMER_POLICY_DEFAULT);
337 
338     sysbus_init_irq(sbd, &t->irq);
339     sysbus_init_irq(sbd, &t->nmi);
340 
341     memory_region_init_io(&t->mmio, OBJECT(t), &timer_ops, t,
342                           "etraxfs-timer", 0x5c);
343     sysbus_init_mmio(sbd, &t->mmio);
344     qemu_register_reset(etraxfs_timer_reset, t);
345 }
346 
347 static void etraxfs_timer_class_init(ObjectClass *klass, void *data)
348 {
349     DeviceClass *dc = DEVICE_CLASS(klass);
350 
351     dc->realize = etraxfs_timer_realize;
352 }
353 
354 static const TypeInfo etraxfs_timer_info = {
355     .name          = TYPE_ETRAX_FS_TIMER,
356     .parent        = TYPE_SYS_BUS_DEVICE,
357     .instance_size = sizeof(ETRAXTimerState),
358     .class_init    = etraxfs_timer_class_init,
359 };
360 
361 static void etraxfs_timer_register_types(void)
362 {
363     type_register_static(&etraxfs_timer_info);
364 }
365 
366 type_init(etraxfs_timer_register_types)
367