xref: /openbmc/qemu/hw/timer/etraxfs_timer.c (revision 135b03cb)
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/main-loop.h"
30 #include "qemu/module.h"
31 #include "qemu/timer.h"
32 #include "hw/irq.h"
33 #include "hw/ptimer.h"
34 
35 #define D(x)
36 
37 #define RW_TMR0_DIV   0x00
38 #define R_TMR0_DATA   0x04
39 #define RW_TMR0_CTRL  0x08
40 #define RW_TMR1_DIV   0x10
41 #define R_TMR1_DATA   0x14
42 #define RW_TMR1_CTRL  0x18
43 #define R_TIME        0x38
44 #define RW_WD_CTRL    0x40
45 #define R_WD_STAT     0x44
46 #define RW_INTR_MASK  0x48
47 #define RW_ACK_INTR   0x4c
48 #define R_INTR        0x50
49 #define R_MASKED_INTR 0x54
50 
51 #define TYPE_ETRAX_FS_TIMER "etraxfs,timer"
52 #define ETRAX_TIMER(obj) \
53     OBJECT_CHECK(ETRAXTimerState, (obj), TYPE_ETRAX_FS_TIMER)
54 
55 typedef struct ETRAXTimerState {
56     SysBusDevice parent_obj;
57 
58     MemoryRegion mmio;
59     qemu_irq irq;
60     qemu_irq nmi;
61 
62     QEMUBH *bh_t0;
63     QEMUBH *bh_t1;
64     QEMUBH *bh_wd;
65     ptimer_state *ptimer_t0;
66     ptimer_state *ptimer_t1;
67     ptimer_state *ptimer_wd;
68 
69     int wd_hits;
70 
71     /* Control registers.  */
72     uint32_t rw_tmr0_div;
73     uint32_t r_tmr0_data;
74     uint32_t rw_tmr0_ctrl;
75 
76     uint32_t rw_tmr1_div;
77     uint32_t r_tmr1_data;
78     uint32_t rw_tmr1_ctrl;
79 
80     uint32_t rw_wd_ctrl;
81 
82     uint32_t rw_intr_mask;
83     uint32_t rw_ack_intr;
84     uint32_t r_intr;
85     uint32_t r_masked_intr;
86 } ETRAXTimerState;
87 
88 static uint64_t
89 timer_read(void *opaque, hwaddr addr, unsigned int size)
90 {
91     ETRAXTimerState *t = opaque;
92     uint32_t r = 0;
93 
94     switch (addr) {
95     case R_TMR0_DATA:
96         r = ptimer_get_count(t->ptimer_t0);
97         break;
98     case R_TMR1_DATA:
99         r = ptimer_get_count(t->ptimer_t1);
100         break;
101     case R_TIME:
102         r = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) / 10;
103         break;
104     case RW_INTR_MASK:
105         r = t->rw_intr_mask;
106         break;
107     case R_MASKED_INTR:
108         r = t->r_intr & t->rw_intr_mask;
109         break;
110     default:
111         D(printf ("%s %x\n", __func__, addr));
112         break;
113     }
114     return r;
115 }
116 
117 static void update_ctrl(ETRAXTimerState *t, int tnum)
118 {
119     unsigned int op;
120     unsigned int freq;
121     unsigned int freq_hz;
122     unsigned int div;
123     uint32_t ctrl;
124 
125     ptimer_state *timer;
126 
127     if (tnum == 0) {
128         ctrl = t->rw_tmr0_ctrl;
129         div = t->rw_tmr0_div;
130         timer = t->ptimer_t0;
131     } else {
132         ctrl = t->rw_tmr1_ctrl;
133         div = t->rw_tmr1_div;
134         timer = t->ptimer_t1;
135     }
136 
137 
138     op = ctrl & 3;
139     freq = ctrl >> 2;
140     freq_hz = 32000000;
141 
142     switch (freq)
143     {
144     case 0:
145     case 1:
146         D(printf ("extern or disabled timer clock?\n"));
147         break;
148     case 4: freq_hz =  29493000; break;
149     case 5: freq_hz =  32000000; break;
150     case 6: freq_hz =  32768000; break;
151     case 7: freq_hz = 100000000; break;
152     default:
153         abort();
154         break;
155     }
156 
157     D(printf ("freq_hz=%d div=%d\n", freq_hz, div));
158     ptimer_set_freq(timer, freq_hz);
159     ptimer_set_limit(timer, div, 0);
160 
161     switch (op)
162     {
163         case 0:
164             /* Load.  */
165             ptimer_set_limit(timer, div, 1);
166             break;
167         case 1:
168             /* Hold.  */
169             ptimer_stop(timer);
170             break;
171         case 2:
172             /* Run.  */
173             ptimer_run(timer, 0);
174             break;
175         default:
176             abort();
177             break;
178     }
179 }
180 
181 static void timer_update_irq(ETRAXTimerState *t)
182 {
183     t->r_intr &= ~(t->rw_ack_intr);
184     t->r_masked_intr = t->r_intr & t->rw_intr_mask;
185 
186     D(printf("%s: masked_intr=%x\n", __func__, t->r_masked_intr));
187     qemu_set_irq(t->irq, !!t->r_masked_intr);
188 }
189 
190 static void timer0_hit(void *opaque)
191 {
192     ETRAXTimerState *t = opaque;
193     t->r_intr |= 1;
194     timer_update_irq(t);
195 }
196 
197 static void timer1_hit(void *opaque)
198 {
199     ETRAXTimerState *t = opaque;
200     t->r_intr |= 2;
201     timer_update_irq(t);
202 }
203 
204 static void watchdog_hit(void *opaque)
205 {
206     ETRAXTimerState *t = opaque;
207     if (t->wd_hits == 0) {
208         /* real hw gives a single tick before reseting but we are
209            a bit friendlier to compensate for our slower execution.  */
210         ptimer_set_count(t->ptimer_wd, 10);
211         ptimer_run(t->ptimer_wd, 1);
212         qemu_irq_raise(t->nmi);
213     }
214     else
215         qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
216 
217     t->wd_hits++;
218 }
219 
220 static inline void timer_watchdog_update(ETRAXTimerState *t, uint32_t value)
221 {
222     unsigned int wd_en = t->rw_wd_ctrl & (1 << 8);
223     unsigned int wd_key = t->rw_wd_ctrl >> 9;
224     unsigned int wd_cnt = t->rw_wd_ctrl & 511;
225     unsigned int new_key = value >> 9 & ((1 << 7) - 1);
226     unsigned int new_cmd = (value >> 8) & 1;
227 
228     /* If the watchdog is enabled, they written key must match the
229        complement of the previous.  */
230     wd_key = ~wd_key & ((1 << 7) - 1);
231 
232     if (wd_en && wd_key != new_key)
233         return;
234 
235     D(printf("en=%d new_key=%x oldkey=%x cmd=%d cnt=%d\n",
236          wd_en, new_key, wd_key, new_cmd, wd_cnt));
237 
238     if (t->wd_hits)
239         qemu_irq_lower(t->nmi);
240 
241     t->wd_hits = 0;
242 
243     ptimer_set_freq(t->ptimer_wd, 760);
244     if (wd_cnt == 0)
245         wd_cnt = 256;
246     ptimer_set_count(t->ptimer_wd, wd_cnt);
247     if (new_cmd)
248         ptimer_run(t->ptimer_wd, 1);
249     else
250         ptimer_stop(t->ptimer_wd);
251 
252     t->rw_wd_ctrl = value;
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_stop(t->ptimer_t0);
315     ptimer_stop(t->ptimer_t1);
316     ptimer_stop(t->ptimer_wd);
317     t->rw_wd_ctrl = 0;
318     t->r_intr = 0;
319     t->rw_intr_mask = 0;
320     qemu_irq_lower(t->irq);
321 }
322 
323 static void etraxfs_timer_realize(DeviceState *dev, Error **errp)
324 {
325     ETRAXTimerState *t = ETRAX_TIMER(dev);
326     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
327 
328     t->bh_t0 = qemu_bh_new(timer0_hit, t);
329     t->bh_t1 = qemu_bh_new(timer1_hit, t);
330     t->bh_wd = qemu_bh_new(watchdog_hit, t);
331     t->ptimer_t0 = ptimer_init(t->bh_t0, PTIMER_POLICY_DEFAULT);
332     t->ptimer_t1 = ptimer_init(t->bh_t1, PTIMER_POLICY_DEFAULT);
333     t->ptimer_wd = ptimer_init(t->bh_wd, PTIMER_POLICY_DEFAULT);
334 
335     sysbus_init_irq(sbd, &t->irq);
336     sysbus_init_irq(sbd, &t->nmi);
337 
338     memory_region_init_io(&t->mmio, OBJECT(t), &timer_ops, t,
339                           "etraxfs-timer", 0x5c);
340     sysbus_init_mmio(sbd, &t->mmio);
341     qemu_register_reset(etraxfs_timer_reset, t);
342 }
343 
344 static void etraxfs_timer_class_init(ObjectClass *klass, void *data)
345 {
346     DeviceClass *dc = DEVICE_CLASS(klass);
347 
348     dc->realize = etraxfs_timer_realize;
349 }
350 
351 static const TypeInfo etraxfs_timer_info = {
352     .name          = TYPE_ETRAX_FS_TIMER,
353     .parent        = TYPE_SYS_BUS_DEVICE,
354     .instance_size = sizeof(ETRAXTimerState),
355     .class_init    = etraxfs_timer_class_init,
356 };
357 
358 static void etraxfs_timer_register_types(void)
359 {
360     type_register_static(&etraxfs_timer_info);
361 }
362 
363 type_init(etraxfs_timer_register_types)
364