xref: /openbmc/qemu/hw/timer/etraxfs_timer.c (revision 0b8fa32f)
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/sysemu.h"
28 #include "qemu/module.h"
29 #include "qemu/timer.h"
30 #include "hw/ptimer.h"
31 
32 #define D(x)
33 
34 #define RW_TMR0_DIV   0x00
35 #define R_TMR0_DATA   0x04
36 #define RW_TMR0_CTRL  0x08
37 #define RW_TMR1_DIV   0x10
38 #define R_TMR1_DATA   0x14
39 #define RW_TMR1_CTRL  0x18
40 #define R_TIME        0x38
41 #define RW_WD_CTRL    0x40
42 #define R_WD_STAT     0x44
43 #define RW_INTR_MASK  0x48
44 #define RW_ACK_INTR   0x4c
45 #define R_INTR        0x50
46 #define R_MASKED_INTR 0x54
47 
48 #define TYPE_ETRAX_FS_TIMER "etraxfs,timer"
49 #define ETRAX_TIMER(obj) \
50     OBJECT_CHECK(ETRAXTimerState, (obj), TYPE_ETRAX_FS_TIMER)
51 
52 typedef struct ETRAXTimerState {
53     SysBusDevice parent_obj;
54 
55     MemoryRegion mmio;
56     qemu_irq irq;
57     qemu_irq nmi;
58 
59     QEMUBH *bh_t0;
60     QEMUBH *bh_t1;
61     QEMUBH *bh_wd;
62     ptimer_state *ptimer_t0;
63     ptimer_state *ptimer_t1;
64     ptimer_state *ptimer_wd;
65 
66     int wd_hits;
67 
68     /* Control registers.  */
69     uint32_t rw_tmr0_div;
70     uint32_t r_tmr0_data;
71     uint32_t rw_tmr0_ctrl;
72 
73     uint32_t rw_tmr1_div;
74     uint32_t r_tmr1_data;
75     uint32_t rw_tmr1_ctrl;
76 
77     uint32_t rw_wd_ctrl;
78 
79     uint32_t rw_intr_mask;
80     uint32_t rw_ack_intr;
81     uint32_t r_intr;
82     uint32_t r_masked_intr;
83 } ETRAXTimerState;
84 
85 static uint64_t
86 timer_read(void *opaque, hwaddr addr, unsigned int size)
87 {
88     ETRAXTimerState *t = opaque;
89     uint32_t r = 0;
90 
91     switch (addr) {
92     case R_TMR0_DATA:
93         r = ptimer_get_count(t->ptimer_t0);
94         break;
95     case R_TMR1_DATA:
96         r = ptimer_get_count(t->ptimer_t1);
97         break;
98     case R_TIME:
99         r = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) / 10;
100         break;
101     case RW_INTR_MASK:
102         r = t->rw_intr_mask;
103         break;
104     case R_MASKED_INTR:
105         r = t->r_intr & t->rw_intr_mask;
106         break;
107     default:
108         D(printf ("%s %x\n", __func__, addr));
109         break;
110     }
111     return r;
112 }
113 
114 static void update_ctrl(ETRAXTimerState *t, int tnum)
115 {
116     unsigned int op;
117     unsigned int freq;
118     unsigned int freq_hz;
119     unsigned int div;
120     uint32_t ctrl;
121 
122     ptimer_state *timer;
123 
124     if (tnum == 0) {
125         ctrl = t->rw_tmr0_ctrl;
126         div = t->rw_tmr0_div;
127         timer = t->ptimer_t0;
128     } else {
129         ctrl = t->rw_tmr1_ctrl;
130         div = t->rw_tmr1_div;
131         timer = t->ptimer_t1;
132     }
133 
134 
135     op = ctrl & 3;
136     freq = ctrl >> 2;
137     freq_hz = 32000000;
138 
139     switch (freq)
140     {
141     case 0:
142     case 1:
143         D(printf ("extern or disabled timer clock?\n"));
144         break;
145     case 4: freq_hz =  29493000; break;
146     case 5: freq_hz =  32000000; break;
147     case 6: freq_hz =  32768000; break;
148     case 7: freq_hz = 100000000; break;
149     default:
150         abort();
151         break;
152     }
153 
154     D(printf ("freq_hz=%d div=%d\n", freq_hz, div));
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 }
177 
178 static void timer_update_irq(ETRAXTimerState *t)
179 {
180     t->r_intr &= ~(t->rw_ack_intr);
181     t->r_masked_intr = t->r_intr & t->rw_intr_mask;
182 
183     D(printf("%s: masked_intr=%x\n", __func__, t->r_masked_intr));
184     qemu_set_irq(t->irq, !!t->r_masked_intr);
185 }
186 
187 static void timer0_hit(void *opaque)
188 {
189     ETRAXTimerState *t = opaque;
190     t->r_intr |= 1;
191     timer_update_irq(t);
192 }
193 
194 static void timer1_hit(void *opaque)
195 {
196     ETRAXTimerState *t = opaque;
197     t->r_intr |= 2;
198     timer_update_irq(t);
199 }
200 
201 static void watchdog_hit(void *opaque)
202 {
203     ETRAXTimerState *t = opaque;
204     if (t->wd_hits == 0) {
205         /* real hw gives a single tick before reseting but we are
206            a bit friendlier to compensate for our slower execution.  */
207         ptimer_set_count(t->ptimer_wd, 10);
208         ptimer_run(t->ptimer_wd, 1);
209         qemu_irq_raise(t->nmi);
210     }
211     else
212         qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
213 
214     t->wd_hits++;
215 }
216 
217 static inline void timer_watchdog_update(ETRAXTimerState *t, uint32_t value)
218 {
219     unsigned int wd_en = t->rw_wd_ctrl & (1 << 8);
220     unsigned int wd_key = t->rw_wd_ctrl >> 9;
221     unsigned int wd_cnt = t->rw_wd_ctrl & 511;
222     unsigned int new_key = value >> 9 & ((1 << 7) - 1);
223     unsigned int new_cmd = (value >> 8) & 1;
224 
225     /* If the watchdog is enabled, they written key must match the
226        complement of the previous.  */
227     wd_key = ~wd_key & ((1 << 7) - 1);
228 
229     if (wd_en && wd_key != new_key)
230         return;
231 
232     D(printf("en=%d new_key=%x oldkey=%x cmd=%d cnt=%d\n",
233          wd_en, new_key, wd_key, new_cmd, wd_cnt));
234 
235     if (t->wd_hits)
236         qemu_irq_lower(t->nmi);
237 
238     t->wd_hits = 0;
239 
240     ptimer_set_freq(t->ptimer_wd, 760);
241     if (wd_cnt == 0)
242         wd_cnt = 256;
243     ptimer_set_count(t->ptimer_wd, wd_cnt);
244     if (new_cmd)
245         ptimer_run(t->ptimer_wd, 1);
246     else
247         ptimer_stop(t->ptimer_wd);
248 
249     t->rw_wd_ctrl = value;
250 }
251 
252 static void
253 timer_write(void *opaque, hwaddr addr,
254             uint64_t val64, unsigned int size)
255 {
256     ETRAXTimerState *t = opaque;
257     uint32_t value = val64;
258 
259     switch (addr)
260     {
261         case RW_TMR0_DIV:
262             t->rw_tmr0_div = value;
263             break;
264         case RW_TMR0_CTRL:
265             D(printf ("RW_TMR0_CTRL=%x\n", value));
266             t->rw_tmr0_ctrl = value;
267             update_ctrl(t, 0);
268             break;
269         case RW_TMR1_DIV:
270             t->rw_tmr1_div = value;
271             break;
272         case RW_TMR1_CTRL:
273             D(printf ("RW_TMR1_CTRL=%x\n", value));
274             t->rw_tmr1_ctrl = value;
275             update_ctrl(t, 1);
276             break;
277         case RW_INTR_MASK:
278             D(printf ("RW_INTR_MASK=%x\n", value));
279             t->rw_intr_mask = value;
280             timer_update_irq(t);
281             break;
282         case RW_WD_CTRL:
283             timer_watchdog_update(t, value);
284             break;
285         case RW_ACK_INTR:
286             t->rw_ack_intr = value;
287             timer_update_irq(t);
288             t->rw_ack_intr = 0;
289             break;
290         default:
291             printf ("%s " TARGET_FMT_plx " %x\n",
292                 __func__, addr, value);
293             break;
294     }
295 }
296 
297 static const MemoryRegionOps timer_ops = {
298     .read = timer_read,
299     .write = timer_write,
300     .endianness = DEVICE_LITTLE_ENDIAN,
301     .valid = {
302         .min_access_size = 4,
303         .max_access_size = 4
304     }
305 };
306 
307 static void etraxfs_timer_reset(void *opaque)
308 {
309     ETRAXTimerState *t = opaque;
310 
311     ptimer_stop(t->ptimer_t0);
312     ptimer_stop(t->ptimer_t1);
313     ptimer_stop(t->ptimer_wd);
314     t->rw_wd_ctrl = 0;
315     t->r_intr = 0;
316     t->rw_intr_mask = 0;
317     qemu_irq_lower(t->irq);
318 }
319 
320 static void etraxfs_timer_realize(DeviceState *dev, Error **errp)
321 {
322     ETRAXTimerState *t = ETRAX_TIMER(dev);
323     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
324 
325     t->bh_t0 = qemu_bh_new(timer0_hit, t);
326     t->bh_t1 = qemu_bh_new(timer1_hit, t);
327     t->bh_wd = qemu_bh_new(watchdog_hit, t);
328     t->ptimer_t0 = ptimer_init(t->bh_t0, PTIMER_POLICY_DEFAULT);
329     t->ptimer_t1 = ptimer_init(t->bh_t1, PTIMER_POLICY_DEFAULT);
330     t->ptimer_wd = ptimer_init(t->bh_wd, PTIMER_POLICY_DEFAULT);
331 
332     sysbus_init_irq(sbd, &t->irq);
333     sysbus_init_irq(sbd, &t->nmi);
334 
335     memory_region_init_io(&t->mmio, OBJECT(t), &timer_ops, t,
336                           "etraxfs-timer", 0x5c);
337     sysbus_init_mmio(sbd, &t->mmio);
338     qemu_register_reset(etraxfs_timer_reset, t);
339 }
340 
341 static void etraxfs_timer_class_init(ObjectClass *klass, void *data)
342 {
343     DeviceClass *dc = DEVICE_CLASS(klass);
344 
345     dc->realize = etraxfs_timer_realize;
346 }
347 
348 static const TypeInfo etraxfs_timer_info = {
349     .name          = TYPE_ETRAX_FS_TIMER,
350     .parent        = TYPE_SYS_BUS_DEVICE,
351     .instance_size = sizeof(ETRAXTimerState),
352     .class_init    = etraxfs_timer_class_init,
353 };
354 
355 static void etraxfs_timer_register_types(void)
356 {
357     type_register_static(&etraxfs_timer_info);
358 }
359 
360 type_init(etraxfs_timer_register_types)
361